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The Vegetation Of The Humid Tropical Region Of North Queensland
Journal of Ecology
... Our reference plots of mature rainforest were situated in the forest vegetation surrounding Lake Barrine (145° 38′ E, 17° 15′ S), a volcanic maar at an altitude of c. 760 m a.s.l., and contained within a c. 500 ha section of the Crater Lakes National Park (NP), and our restoration plots in a revegetated forest (Donaghy's Corridor, see later) just southeast of the lake (Fig. 1). There is no long-term rainfall gauge data available in the vicinity; however mean annual rainfall is believed to be about 2.5 m; mean annual temperatures vary from 25°C in January to 15.5°C in July (Tracey 1982). ...
... The Lake Barrine section of the Crater Lakes NP is comprised primarily of mature tropical rainforest known as complex mesophyll vine forest (Tracey 1982) and as Regional Ecosystem 7.8.2 (Goosem et al. 1999). This rainforest type grows over basaltic soils, and is characterized by well-developed canopy stratification, the conspicuous presence of trees with plank roots, numerous robust woody lianas, and a high diversity of lifeforms (Tracey 1982). ...
... The Lake Barrine section of the Crater Lakes NP is comprised primarily of mature tropical rainforest known as complex mesophyll vine forest (Tracey 1982) and as Regional Ecosystem 7.8.2 (Goosem et al. 1999). This rainforest type grows over basaltic soils, and is characterized by well-developed canopy stratification, the conspicuous presence of trees with plank roots, numerous robust woody lianas, and a high diversity of lifeforms (Tracey 1982). At a broader landscape scale, Lake Barrine is a forest fragment which in precolonial times was continuous with a larger block of rainforest in Gadgarra NP, due southeast ( Fig. 1). ...
Restoration of forest ecosystems is a global imperative, yet there are relatively few studies assessing the success of old forest restoration efforts in the tropics. We assessed the vegetation structure, species diversity and composition of a 25-year-old wildlife corridor restoration site linking two patches of mature rainforest in the uplands of the Wet Tropics of Australia. Our results show that the vegetation structure of the restored rainforest was similar to that of mature reference rainforest in profile, in the overall stem size class distribution, in plot level means of stem basal areas and in the number of individuals. Reference mature rainforest had significantly higher plot-level mean biomass than was found in restored rainforest. Species richness and diversity indices of the two forest types also showed differences, and these were significant in terms of species composition, with the mature rainforest having a higher percentage of wind or mechanically dispersed species, and restored rainforest having more animal dispersed species. Although the restored rainforest is not compositionally similar to mature rainforest, the habitat it provides for wildlife and the presence of many mature rainforest species recruiting in the restored rainforest are positive restoration outcomes. Future monitoring and comparisons with other revegetated sites or naturally regenerating forest will provide deeper insights into the processes of recovery in restored forests.
... The possibility of undescribed species has been recognised for some time (Bailey 1935;Moore 1965;Tracey 1982;Rodd 1983;Jones 1984;Tucker 1988). Some of these taxa have received 'tag names' based on their locality, for example 'Mt Lewis Archontophoenix' 'Rocky River Archontophoenix' and 'Myola Archontophoenix'; such names have been adopted in both botanical and horticultural literature. ...
... It also occurs commonly on interfluve ridges as a rainforest subcanopy element in very wet regions (up to 2500 mm rainfall per annum) as well as occurring in gallery forests along seasonally dry creeks. Soil types are diverse and include a variety of bedrocks; for example on basaltic and alluvial soils (Tracey 1982) and poorly drained piedmont alluvial terraces and lower granite footslope colluvium (Graham & Hopkins 1980) (1865). Bailey (1902) noted that this illustration was "not good, the stem too slender", thus suggesting it not to be a true representation. ...
... Populations are numerous though small, usually including no more than about 20 individuals. Tracey (1982) recorded this species in simple microphyll vine/fern forest on Mts Spurgeon and Lewis. Occurrence on Mt Finnigan is on the north-east face in vine forests restricted to gullies at 400-600 m altitude and in simple notophyli forest at 600-1 100 m altitude. ...
... The closed canopy is usually 20-25 m high with frequent tree species including Syzygium luehmannii, Canarium Floristic characteristics: (wind disturbed WET and CYP) The dense canopy is between 15 and 30 m tall and may be dominated solely by Acacia celsa (upland areas), or A. celsa in combination with A. cincinnata, A. polystachya, A. mangium (foothills and lowlands) or A. melanoxylon (higher altitudes). The vine forest understorey is usually 5-10 m below the canopy and includes a number of species that have been described by Tracey (1982) Types 12a, b, c, & d. Cordyline cannifolia, Linospadix spp., the ferns Blechnum cartilagineum and Parapolystichum spp. the graminoids Exocarya scleroides and Lomandra longifolia and the tree fern Alsophila rebeccae are prominent in the ground layer (Tracey 1982 type 8). ...
... Floristic characteristics (WET 800-1300 m altitude): A simple microphyll vine fern forest (Tracey 1982 Type 9) usually occurs. The canopy is even but only 20-25 metres tall, with patches of emergent Agathis atropurpurea in places (at higher elevations Floristic characteristics (WET above 1300 m altitude): A simple microphyll vine fern thicket occurs with the dense canopy only 10-12 m tall, and wind-sheared emergent Leptospermum wooroonooran to 15 m tall (Tracey 1982 Type 10). ...
... Floristic characteristics (WET 800-1300 m altitude): A simple microphyll vine fern forest (Tracey 1982 Type 9) usually occurs. The canopy is even but only 20-25 metres tall, with patches of emergent Agathis atropurpurea in places (at higher elevations Floristic characteristics (WET above 1300 m altitude): A simple microphyll vine fern thicket occurs with the dense canopy only 10-12 m tall, and wind-sheared emergent Leptospermum wooroonooran to 15 m tall (Tracey 1982 Type 10). Frequent canopy species include Acmena hemilampra subsp. ...
... The closed canopy is usually 20-25 m high with frequent tree species including Syzygium luehmannii, Canarium Floristic characteristics: (wind disturbed WET and CYP) The dense canopy is between 15 and 30 m tall and may be dominated solely by Acacia celsa (upland areas), or A. celsa in combination with A. cincinnata, A. polystachya, A. mangium (foothills and lowlands) or A. melanoxylon (higher altitudes). The vine forest understorey is usually 5-10 m below the canopy and includes a number of species that have been described by Tracey (1982) Types 12a, b, c, & d. Cordyline cannifolia, Linospadix spp., the ferns Blechnum cartilagineum and Parapolystichum spp. the graminoids Exocarya scleroides and Lomandra longifolia and the tree fern Alsophila rebeccae are prominent in the ground layer (Tracey 1982 type 8). ...
... Floristic characteristics (WET 800-1300 m altitude): A simple microphyll vine fern forest usually occurs (Tracey 1982 Type 9), sometimes down to 600 m. The canopy is even but only 20-25 metres tall, with patches of emergent Agathis atropurpurea in places (at higher elevations Floristic characteristics (WET above 1300 m altitude): A simple microphyll vine fern thicket occurs with the dense canopy only 10-12 m tall, and wind-sheared emergent Leptospermum wooroonooran to 15 m tall (Tracey 1982 Type 10). ...
... Floristic characteristics (WET 800-1300 m altitude): A simple microphyll vine fern forest usually occurs (Tracey 1982 Type 9), sometimes down to 600 m. The canopy is even but only 20-25 metres tall, with patches of emergent Agathis atropurpurea in places (at higher elevations Floristic characteristics (WET above 1300 m altitude): A simple microphyll vine fern thicket occurs with the dense canopy only 10-12 m tall, and wind-sheared emergent Leptospermum wooroonooran to 15 m tall (Tracey 1982 Type 10). Frequent canopy species include Acmena hemilampra subsp. ...
The Vegetation of Queensland. Descriptions of Broad Vegetation Groups. This publication summarises the diverse vegetation of Queensland, Australia by describing and mapping 98 broad vegetation groups which summarise the 1449 regional ecosystems that occur in the State.
... Some of the trees are deciduous (Webb 1959:552). Tracey and Webb (1975) and Tracey (1982) have developed a detailed structural classification for rainforest and related vegetation types in the Wet Tropics. Thirteen sub-formations of rainforest, as well as 10 types of rainforest with emergent sclerophylls, have been identified. ...
... 1c. Local on very wet to wet lowlands and river valleys, canopy 36-42 metres on alluvial deposits (Tracey and Webb 1975;Tracey 1982). ...
... Now very restricted on cloudy wet highlands and on moist to dry lowlands, foothills and uplands but before European clearing more common toward the rainfall limit of rainforest, for example on the Atherton Tablelands north and west of Malanda. On basalts (Tracey and Webb 1975;Tracey 1982). ...
... However, the last half a century of research has revealed that the Wet Tropics host uniquely high concentrations of all plant groups, including angiosperm and gymnosperm species, with evolutionary histories tracing back to Gondwanaland (Webb and Tracey, 1994;Sanderson, 2008), containing 19 of 26 near basal families of dicotyledonous plants and 626 species endemic to Australia (Metcalfe and Ford, 2009;Wet Tropics Management Authority, 2016). Beyond the rainforest, more open, drier, and varied sclerophyll forests host a further variety of endemic Australian plant species (Tracey, 1982). Although the Wet Tropics covers only 0.12% of Australia, it also contains approximately 45% of all Australian terrestrial vertebrate species, a quarter of which have special conservation value (Wet Tropics Management Authority, 2016). ...
... The Wet Tropics is home to a diversity of forest types that have seen significant temporal fluctuations in their distribution in the past (Kershaw et al., 2007). Tracey and Webb (1975) and Tracey (1982) have developed a detailed structural classification for rainforest and related vegetation types in the Wet Tropics. Thirteen sub-formations of rainforest, as well as 10 types of rainforest with emergent sclerophylls, have been identified. ...
... Nevertheless, there has thus far been relatively little discussion of the scale of this occupation. Commonly cited estimates of the pre-contact Aboriginal population numbers in the region, based on European census data and ethnographic analysis, lie around 5,500 people (Harris, 1978;Tracey, 1982), a number that perhaps suggests limited pre-colonial impact on the environments of the Wet Tropics. This is particularly the case given assumptions that the rainforests of the Wet Tropics would have been broadly unattractive to human settlement, a perspective also used to explain a relatively late occupation of the region, with toxic nuts and tubers, and sparse, difficult-to-catch fauna only becoming desirable in the Mid-Holocene when specialized adaptations to the attainment and processing of these foods arose in response to climate change (Cosgrove, 1996;Cosgrove et al., 2007). ...
The ‘Wet Tropics’ of Australia host a unique variety of plant lineages that trace their origins to the super-continent of Gondwanaland. While these ‘ancient’ evolutionary records are rightly emphasised in current management of the region, multidisciplinary research and lobbying by Rainforest Aboriginal Peoples have also demonstrated the significance of the cultural heritage of the ‘Wet Tropics’. Here, we evaluate the existing archaeological, paleoenvironmental, and historical evidence to demonstrate the diverse ways in which these forests are globally significant, not just for their ecological heritage, but also for their preservation of traces of millennia of anthropogenic activities, including active burning and food tree manipulation. We argue that detailed palaeoecological, ethnobotanical, and archaeological studies, working within the framework of growing national and world heritage initiatives and active application of traditional knowledge, offer the best opportunities for sustainable management of these unique environments in the face of increasingly catastrophic climate change and bushfires.
... Mosses and liverworts, the major groups of bryophytes, are a significant component of the biodiversity in the Australian wet tropics, in north-east Queensland, occurring in all ecosystems as colonisers of soil, rocks, fallen logs, and as epiphytes and epiphylls. While much attention has been paid to the vascular plants, vegetation types and ecology of tropical north-east Queensland (Tracey & Webb 1975, Kershaw 1978, Tracey 1982, R.M. Schuster (in Keto & Scott 1986) emphasised the importance of bryophytes in the region and criticised the paucity of studies. ...
... 15-19°S, long. 145-146°30'E) (approximating the Wet Tropics bioregion) was described by Tracey (1982), based on Webb (1959Webb ( , 1968Webb ( , 1978 and Tracey and Webb (1975) for rainforests, and Specht (1970) for other vegetation communities. Vegetation descriptions are currently under review , 2001a, 2001b. ...
... Vegetation descriptions are currently under review , 2001a, 2001b. Thirteen rainforest structural types (Webb 1968) are recognised within the Wet Tropics bioregion (Tracey 1982). ...
Abstract (updated): A checklist of the mosses (Bryophyta) of the Wet Tropics bioregion, north-east Queensland is presented. Included is an update on the taxonomy of species, listing a total of 397 taxa. The habitat and distribution patterns of species within the area and in Australia, together with information on the phytogeographical affinities of these taxa in related areas beyond Australia, are discussed.
... E; Mokany, Westcott, Prasad, Ford, & Metcalfe, 2014; see Figure 2a). Thus, our analysis extends from contiguous closed forest near the coast (e.g., the area surrounding Mt Bellenden Ker receives >10,000 mm of annual rainfall in some years) into the seasonally dry monsoonal inlands, where scattered pockets of rainforest experience seasonal drought (Tracey, 1982;Webb, Tracey, & Williams, 1976;. ...
... Indeed, several decades of research illustrate that the spatial turnover of plant species across the WT is determined by complex, fine-scale interactions between turnover in climate, topography, soil and biotic factors (e.g., Bowman, 2000;Mackey, 1994;Webb, 1959Webb, , 1968. In particular, site fertility and topographic wetness are significant determinants of vegetation composition, plant height, canopy density and leaf size in the WT (Tracey, 1969;Webb, 1969 Lance, 1970), with height being strongly correlated with productivity (Tracey, 1982;Webb, 1959;Webb et al., 1970). Unfortunately, these non-climatic factors cannot be quantified at macroecological scales. ...
... Furthermore, the GPP of individual sites in the humid, monsoonal climate of the Wet Tropics will be influenced strongly by water stress and extremes of temperature across inter-annual wet-dry cycles (Tracey, 1982;Webb et al., 1984). Thus, we specified the site-level explanatory factors of GPP as the mean total monthly rainfall (in millimetres per month) and the mean daily maximum temperature of each month (in degrees Celsius). ...
Aim
A key ecological debate is whether ecosystem functions are distinctly influenced by biological diversity across broad scales. Although recent work has emphasized the importance of links between ecosystem functions and measures of ecological specialization as proxies of biodiversity, few studies have analysed macroecological relationships empirically in diverse environments. We tested whether gross primary productivity (GPP) in the Australian Wet Tropics (WT) was distinctly related to community‐level measures of the ecological specialization of component tree species across climate space, after accounting for climate drivers.
Location
Wet Tropics, Australia.
Time period
1976–2012.
Major taxa studied
Nine hundred and forty‐eight WT tree species.
Methods
Using all geographically valid herbarium records for WT trees, we quantified the realized climatic niche widths using continental surfaces for maximum temperature of the warmest period and total annual rainfall. The median realized niche width for all tree species occurring at 510 sites was used to approximate ecological specialization within communities. To separate climatic effects on GPP, we applied a novel analysis using the difference in GPP and the difference in median community realized niche width between site pairs with similar climatic conditions. Linear models were then run on the difference in GPP between site pairs (response) and the difference in climatic niche widths (predictor).
Results
For climatically similar sites in drier areas, GPP was higher in sites composed of species with narrower temperature niches (average R² = 0.087, average t‐statistic = −3.45). Conversely, for climatically similar sites in drier areas, GPP was lower in sites composed of species with narrower rainfall niches (average R² = 0.171, average t‐statistic = 5.06).
Main conclusions
Wet Tropics sites with more thermal specialists had higher productivity, whereas sites with more moisture specialists had lower productivity. These findings suggest that physiological specialization across climate space can influence primary productivity at broad scales, but in inconsistent ways.
... The undulating plateaus of the Atherton and Evelyn tablelands rise to 600-900 m a.s.l. and persistent cloud cover maintains moist conditions on the higher mountain ranges all year around (Kershaw 1994). The climate is tropical with occasional cyclones and an average rainfall of over 2,000 mm per annum, most of which falls in the monsoonal wet season from November to April (Tracey 1982). The current extent of vegetation in the Wet Tropics bioregion forms a contiguous canopy of humid tropical rainforest interspersed with patches of pyrophytic sclerophyll open forest and woodland (Hopkins et al. 1993). ...
... The contemporary vegetation at Goddard Creek is simple notophyll vine forest (SNVF) ( Fig. 2; Wet Tropics Management Authority 2009) which represents the most extensive and homogeneous upland rainforest type in the wet tropics (Tracey 1982, p 32). SNVF in the cloudy wet tablelands is described as floristically very species rich (Queensland Department of Environment, Land and Water 2017) and noted as a biodiversity hotspot for phylogenetic diversity and taxonomic richness (Costion et al. 2014). Its structural formation is characterised by an even-aged canopy of tall closed forest up to 33 m high and occasional emergents up to 35 m (Tracey 1982). Tree girth diameter is uniform with exception of emergent and plank buttresses, and described as "pole forests" by Tracey (1982, p 32). ...
... The site's surface geology is granite with a red brown gradational soil consisting of sandy loam to medium clay at depth (Tracey 1982). Excavations were conducted on the site during the field seasons of 2002 and 2004 and consisted of two squares (A1 and A5) which were both 1 m × 1 m in size located 5 m apart, as well as a 1 m × 5 m trench (Fig. 3). ...
Anthracology, the systematic recovery and analysis of wood charcoal from archaeological sites, provides insights into past subsistence practices, socio-ecological interactions and palaeoenvironments. A pilot study focusing on the identification of firewood taxa from the late Holocene deposit at Goddard Creek has revealed the fuel choices and collection patterns of Rainforest Aboriginal people in the settlement of upland notophyll rainforest on the Evelyn tableland in northeast Queensland, Australia. The analysis indicates the existence of a floristically rich rainforest site at the time of occupation, with potentially up to 90 different rainforest taxa recorded, including the positive identification of 37 taxa. Firewood used in association with toxic nut processing at the site consisted of the preferential selection of fresh Rhodamnia sp. wood and Citronella sp. branches, possibly for specialised functions, as well as a range of other taxa that were collected according to availability from the surrounding rainforest. These preliminary results demonstrate the potential of anthracological analysis for archaeological interpretations in tropical Australia, while highlighting the continuing efforts required to successfully apply the discipline in this region. This study contributes to the wider research into the history of the wet tropics cultural landscape and is the first application of systematic wood charcoal studies to an archaeological site in the wet tropical rainforests of Australia.
... The remnant vegetation of the area is described as complex mesophyll vine forest and notophyll vine forest with drier areas transitioning into complex semievergreen notophyll vine forest (Queensland Herbarium, 2015;Tracey, 1982). Within the complex mesophyll vine forest, multiple intact canopies may be present with the upper canopy averaging a height of 20-40 m and emergent trees reaching 55 m (Queensland Herbarium, 2015;Tracey, 1982). ...
... The remnant vegetation of the area is described as complex mesophyll vine forest and notophyll vine forest with drier areas transitioning into complex semievergreen notophyll vine forest (Queensland Herbarium, 2015;Tracey, 1982). Within the complex mesophyll vine forest, multiple intact canopies may be present with the upper canopy averaging a height of 20-40 m and emergent trees reaching 55 m (Queensland Herbarium, 2015;Tracey, 1982). ...
... Deciduous tree species are rare; however, woody lianas, epiphytes, and ferns are common resulting in a complex forest structure (Tracey, 1982). ...
Closed-canopy forests are being rapidly fragmented across much of the tropical world. Determining the impacts of fragmentation on ecological processes enables better forest management and improves species-conservation outcomes. Lianas are an integral part of tropical forests but can have detrimental and potentially complex interactions with their host trees. These effects can include reduced tree growth and fecundity, elevated tree mortality, alterations in tree-species composition, degradation of forest succession, and a substantial decline in forest carbon storage. We examined the individual impacts of fragmentation and edge effects (0-100-m transect from edge to forest interior) on the liana community and liana-host tree interactions in rainforests of the Atherton Tableland in north Queensland, Australia. We compared the liana and tree community, the traits of liana-infested trees, and determinants of the rates of tree infestation within five forest fragments (23-58 ha in area) and five nearby intact-forest sites. Fragmented forests experienced considerable disturbance-induced degradation at their edges, resulting in a significant increase in liana abundance. This effect penetrated to significantly greater depths in forest fragments than in intact forests. The composition of the liana community in terms of climbing guilds was significantly different between fragmented and intact forests, likely because forest edges had more small-sized trees favoring particular liana guilds which preferentially use these for climbing trellises. Sites that had higher liana abundances also exhibited higher infestation rates of trees, as did sites with the largest lia-nas. However, large lianas were associated with low-disturbance forest sites. Our study shows that edge disturbance of forest fragments significantly altered the abundance and community composition of lianas and their ecological relationships with trees, with liana impacts on trees being elevated in fragments relative to intact forests. Consequently, effective control of lianas in forest fragments requires management practices which directly focus on minimizing forest edge disturbance.
... The method originated in tropical north Queensland, Australia in the 1980s. Tree species lists for the region's 13 forest types [12,13] and observations of tree performance at local arboreta provided a foundation for candidate-species selection, while effective propagation techniques for hundreds of indigenous forest tree species were developed in a native tree nursery. Initial field trials from 1985 to 2000, at three sites (11-730 m.a.s.l.) screened out unsuitable species. ...
... Methods that adapt several of the FSM principles have been devised to specifically promote use of native tree species and biodiversity recovery in systems aimed at food and timber production, particularly where human population pressure is high, e.g. 'rainforestation' in the Philippines [13,14]. ...
As interest in restoring tropical forests surges, so does the need for effective methods to ensure success. The framework species method (FSM) restores forest ecosystems by densely planting open sites, close to natural forest, with woody species, indigenous to the reference ecosystem and selected for their ability to accelerate ecological succession. Criteria for selecting framework species include: (i) representative of the reference forest ecosystem, (ii) tolerant of open conditions, (iii) ability to suppress weeds, (iv) attractiveness to seed-dispersing animals and (v) easily propagated. The method is effective where forest remnants and viable populations of seed dispersers remain. The origins and elements of the FSM are discussed. We review its adoption in 12 countries. Adherence to original principles was mostly high, but some misuse of the term was evident. The need for clearer definitions was identified. We place the FSM on a scale of restoration methods, matched with degradation levels and compare its establishment costs with those of other methods. Obstacles to its wider adoption, both technical and socio-economic, are discussed, along with how these might be overcome. Finally, the FSM is more clearly defined to facilitate its use in contributing towards the goals of the UN Decade on Restoration.
This article is part of the theme issue ‘Understanding forest landscape restoration: reinforcing scientific foundations for the UN Decade on Ecosystem Restoration’.
... Spec section of Paluma Range National Park (18"5 7'S, 1401 1'E, altitude 880-900 m), which is about 80 km north of Townsville, north Queensland (Fig 2.5). Paluma is an upper montane rain forest, classified as a simple notophyll vine forest (Tracey 1982), which is characterized by a relatively even canopy surface, mostly notophyll leaves, commonly slender and wiry vines (few robust woody lianas), and frequent epiphytes in tree crowns (Talley et al. 1996). Average annual rainfall in this area is about 3375 mm ( Fig. 2.6), in which more rain falls during the wet season (December to April) (Gross 1993 in Talley et al. 1996). ...
... Samples of R. australasica were collected in the Henrietta Creek section of Wooroonooran National Park, which is about 30 km west of Innisfail, north Queensland (Fig 2.5). This forest is classified as a complex mesophyll vine forest (Tracey 1982). According to Gleason et al. (2008), this ecosystem is classified as sub-tropical wet forest based on Holdridge's (1947) ...
Secondary hemi-epiphytes start their life as ground-dwelling plants. Like other vines, the plant then climbs the host, but when the plant reaches maturity, the oldest portion of the stem dies. The plant then loses its stem connection to the soil and becomes semi-epiphytic. However, true secondary hemi-epiphytism is probably not as common as thought, since, in most cases semi-epiphytic vines reconnect to the soil through aerial roots. The change in soil connection during the ontogeny of these species may have physiological and anatomical consequences. As they eventually live in the canopy environment, it is feasible that secondary hemi-epiphytes might develop adaptations to cope with the stressful canopy environment, especially water stress during dry periods. However, there is a lack of understanding on the ecophysiology of secondary hemi-epiphytes in rainforests.
There is a paucity of information on the anatomy and physiology of secondary hemi-epiphytes, once they lose their stem connection to the soil, compared with the terrestrial early stage of development. To address this knowledge gap, characteristics of stem water transport, leaf anatomy and physiology, and soil water resource partitioning were examined in this research. Two species were selected for the study: Freycinetia excelsa F. Muell (Pandanaceae) and Rhaphidophora australasica F.M. Bailey (Araceae), which occur naturally in the Wet Tropics area of north Queensland. The general objective of this research is to better understand the ecophysiology of secondary hemi-epiphytes during their ontogenetic development.
The capacity of F. excelsa and R. australasica stems to conduct water differed between plants of different developmental phases. Adult individuals of F. excelsa and R. australasica had wider vessels than younger plants. Hydraulic architecture parameters, i.e. hydraulic conductivity, stem specific conductivity and leaf specific conductivity, were also higher in adult plants than for intermediate and juvenile individuals. These results indicate that adult plants had a higher capacity to conduct water through the stem to the leaves than did individuals at an earlier stage of development.
As the plants became more mature and longer, they tended to have low hydraulic conductivity at the stem base. This finding is supported by the fact that the size of xylem vessels was found to decrease in the basipetal direction: the base of the stem had narrower vessels than the middle part of the stem. However, the low hydraulic conductivity at the base of the stem may also be related to the fact that monocotyledonous plants lack secondary development. Therefore, the stem base contains the oldest shoot tissues and the vessels might be less functional. Wider vessels and higher hydraulic conductivity in adult individuals of F. excelsa and R. australasica show that the change in plant-soil connectivity during ontogeny of these species does not physically restrict water transport.
Adult individuals of F. excelsa and R. australasica had larger stomata than conspecific juveniles. However, adult plants also had more stomata per unit area, which gives them more control of the opening and closing of stomata in certain areas of the leaves. These characteristics of leaf anatomy suggest that secondary hemi-epiphytes are well-adapted to the canopy environment.
Juvenile plants of these two study species appear to be more sensitive to the onset of drought than plants of later developmental stages. Within each dry and wet season, the water potential of leaves from all growth forms were similar but the patterns of daily CO2 exchange differed, with CO2 uptake by juvenile plants most affected by dry season conditions. However, the CO2 exchange rates were similar for adult, intermediate and juvenile plants during the wet season. High water availability in the wet season and relatively low evaporative demands provide excellent conditions for plants to absorb CO2. The significant down-regulation of CO2 exchange in the dry season in the juveniles is related to the lower hydraulic conductivity of their stems. Water supply to juveniles may be restricted during the dry season, such that down-regulation of CO2 uptake and stomatal opening are necessary to diminish water loss and maintain water potential. Water supplied to intermediate and adult plants by aerial roots growing from a number of places along the stem is evidently sufficient to sustain higher rates of CO2 exchange and water loss.
Plants of different ontogenetic stages had different behaviours towards soil water resources. Based on the hydrogen stable isotopes of water derived from different layers of the soil profile, matched with isotope signatures of the stem water, water uptake by juvenile individuals was limited to the area near the soil surface; on the other hand, adult plants utilized water from all soil layers studied. This consequently affects the capacity of plants to exploit all available soil water sources across seasons, which influences the performance of individuals of different ontogenetic stages in response to environmental conditions.
Variations in the ecophysiological attributes of the secondary hemi-epiphytes F. excelsa and R. australasica indicate differences in the ability of these plants to survive during their development. This study showed that smaller size juveniles may have a higher potential susceptibility to stressful environmental conditions compared to larger adult congeners. Based on ecophysiological characters, these two secondary hemi-epiphytic have not adapted especially to the epiphytic habit as they climb the host and live in the canopy. The plants’ soil connections through aerial roots provide access to soil, avoid the stem basal hydraulic bottle neck and contribute to more options for soil water resource acquisition.
... Allocasuarina torulosa, the Forest Oak, is also dioecious and similar in form to A. littoralis but is more prevalent on the dry sclerophyll slopes of hinterland areas. While not commonly found together, both species occasionally occur sympatrically in coastal and hinterland areas (Tracey 1982;Crowley 1986). The main flowering period for Allocasuarina is during the winter months with infructescences (cones) taking 6 to 9 months to mature (Moncur et al. 1997). ...
... Cones are produced on peduncles along the main stem and branches with mixing of annual cohorts, making it difficult to estimate cone/seed age by their position on the tree. Seed can be held serotinously for up to three decades and is only released upon the death of the supporting limb by fire or mechanical damage (Tracey 1982;Crowley 1986). Seed viability, as determined by germination rate, has been found to decline progressively from an initial 60% to <10% within 12 years after seed set, possibly sooner (Pannell and Myerscough 1993). ...
Habitat modification and destruction are known to be responsible for declines in avian taxa. Specialist species such as the vulnerable Glossy Black-cockatoo (Calyptorhynchus lathami ssp. lathami) are particularly at risk due to the limited number of Casuarina and Allocasuarina species on which they feed, which is compounded by their propensity for selecting only specific individual feed trees within patches. This study aims to address the lack of understanding surrounding Glossy Black-cockatoo feeding ecology in southeast Queensland, Australia, by examining determinants of tree selection for Allocasuarina littoralis and A. torulosa. We conducted surveys to identify feed and non-feed trees of both Allocasuarina species, and differences between the physical and chemical characteristics of trees, cones, and seeds were investigated. We found that larger trees were preferentially foraged, with nutritional profitability as the primary factor governing tree selection. Feed tree cones had higher seed number and seed mass, with seeds containing higher levels of fatty acids and nutrients than non-feed tree cones. We conclude that further research should aim to delineate the factors contributing to these differences, alongside determining appropriate management strategies to support viable feeding habitat, which is most likely comprised of mixed age patches, capable of maintaining mature trees offering sufficient nutrient reward.
... Additionally, sclerophyll forest, dominated by eucalyptus and acacias, is also found in the Wet Tropics. Mesophyll forests occur in very wet to moist lowland areas with the dominant canopy tree species having an average leaf length of more than 12.5 cm, while microphyll forests generally occur in wet highland areas with the dominant canopy tree species having an average leaf length of less than 7.5 cm (Tracey, 1982;Webb, 1968). Notophyll forests are the most extensive rainforest type in the Wet Tropics bioregion ranging from the foothills to the uplands with dominant canopy tree species having an average leaf length of 7.5-12.5 cm (Tracey, 1982;Webb, 1959Webb, , 1968WTMA, 2014) (details in Supplementary Materials). ...
... Mesophyll forests occur in very wet to moist lowland areas with the dominant canopy tree species having an average leaf length of more than 12.5 cm, while microphyll forests generally occur in wet highland areas with the dominant canopy tree species having an average leaf length of less than 7.5 cm (Tracey, 1982;Webb, 1968). Notophyll forests are the most extensive rainforest type in the Wet Tropics bioregion ranging from the foothills to the uplands with dominant canopy tree species having an average leaf length of 7.5-12.5 cm (Tracey, 1982;Webb, 1959Webb, , 1968WTMA, 2014) (details in Supplementary Materials). ...
Tropical forests are the storehouse of both ecosystem services and biodiversity but the interlinkages between these two components of ecosystems are yet to be fully explored. We utilized expert opinion to assess the key and multiple ecosystem services, and biodiversity in a tropical landscape. We found that key and multiple ecosystem services supply varies across the landscape and that forest disturbances reduce the capacity to supply those ecosystem services. We also found that a spatial congruence is likely to occurs between high-potential biodiversity and high-potential global climate regulation ecosystem service in the intact rainforest areas while a spatial divergence is likely to occurs in the sclerophyll and other disturbed and low tree abundance forested areas. Overall in a tropical forested landscape, a spatial congruence between high-potential multiple ecosystem services supply and high-potential biodiversity values is likely to occurs provided that the multiple ecosystem services are forest-based. Along with conserving relatively intact forests, management intervention priorities should focus on increasing tree abundance both in non-tree vegetated land cover areas and within disturbed forested areas to increase the high-potential multiple ecosystem services supply at the landscape level. A careful selection of multiple ecosystem services is required to integrate both high-potential multiple ecosystem services and high-potential biodiversity in tropical forest management.
... Donaghy's Corridor is a 16.4 ha block of restored riparian-zone habitat linking the isolated 505 ha Lake Barrine section of Crater Lakes National Park to Wooroonooran National Park (80,000 ha). Located in the tropical highlands at 720 m a.s.l, the site receives annual rainfall of 1428 mm (mostly between November and March), with average temperatures varying from 17.1°C in winter to 27.3°C in summer (Tracey 1982). Planting of around 17,000 stems from 101 species was undertaken over four years from 1995 to 1998 to establish the corridor along Toohey Creek, converting cattle pasture and 1.75 ha of regrowth into a wildlife corridor between two World Heritage Area properties separated since the 1940s (Tucker & Simmons 2009). ...
Re-establishing ecological connectivity between remnants and continuous forest can counter the effects of fragmentation and climate change by strategically increasing habitat area and improving movement potential. To evaluate the effect of restoring habitat between an isolated fragment and adjacent intact rainforest, we re-surveyed vegetation, birds and ground mammals in a restored wildlife corridor over a 12-month period in 2021, comparing results to data from 1996-1998 (birds) and 2000 (vegetation and mammals). Over 150 naturally regenerating plants were recorded; birds were primarily responsible for seed dispersal. Numbers of large-seeded (>30 mm dia.) and late successional species dispersed by birds and mammals have increased. Bird and mammal assemblages are increasingly similar to adjacent reference forest, although some endemic birds remain absent. Germination of some large-fruited species coincides with colonisation by the only mammals capable of their dispersal; generalist mammals have been replaced by rainforest specialists. After nearly 25 years, plantings have produced a structurally complex habitat inhabited by many species, and tropical restoration projects in similar settings may achieve comparable responses.
... The phenological observations and physiological measurements for this study were conducted in lowland tropical rainforest at the DRO administered by James Cook University (16 • 06 20 S 145 • 26 40 E, 50 m a.s.l.), in northeastern Queensland, Australia. The rainforest at the study site has been classified as complex mesophyll vine forest (Tracey, 1982;Goosem et al., 1999). The vegetation at the DRO has an uneven height and heterogeneous floristic composition, with the canopy comprising a mixture of both mesophyll and notophyll species spread across a wide range of phylogenies (Laidlaw et al., 2007). ...
Climate change is expected to increase the intensity and occurrence of drought in tropical regions, potentially affecting the phenology and physiology of tree species. Phenological activity may respond to a drying and warming environment by advancing reproductive timing and/or diminishing the production of flowers and fruits. These changes have the potential to disrupt important ecological processes, with potentially wide-ranging effects on tropical forest function. Here, we analysed the monthly flowering and fruiting phenology of a tree community (337 individuals from 30 species) over 7 years in a lowland tropical rainforest in northeastern Australia and its response to a throughfall exclusion drought experiment (TFE) that was carried out from 2016 to 2018 (3 years), excluding approximately 30% of rainfall. We further examined the ecophysiological effects of the TFE on the elemental (C:N) and stable isotope (δ13C and δ15N) composition of leaves, and on the stable isotope composition (δ13C and δ18O) of stem wood of four tree species. At the community level, there was no detectable effect of the TFE on flowering activity overall, but there was a significant effect recorded on fruiting and varying responses from the selected species. The reproductive phenology and physiology of the four species examined in detail were largely resistant to impacts of the TFE treatment. One canopy species in the TFE significantly increased in fruiting and flowering activity, whereas one understory species decreased significantly in both. There was a significant interaction between the TFE treatment and season on leaf C:N for two species. Stable isotope responses were also variable among species, indicating species-specific responses to the TFE. Thus, we did not observe consistent patterns in physiological and phenological changes in the tree community within the 3 years of TFE treatment examined in this study.
... Ecologists in Australia favour fine-scale tropical rainforest classification systems and maps that have been derived from decades of intensive study (e.g. Webb, 1959;Tracey and Webb, 1975;Tracey, 1982;WTMA, 2009). Other montane ecosystems in the world have not received this level of attention. ...
... The nearest extensive rainforest is 3 km to the east. Most of the Park is on fertile basalt soil supporting larger-leaved complex rainforest, but forest types with smaller leaves and simpler structures occur on less fertile metamorphic soils in the south-east and southwest (Tracey 1982;Queensland Government 2020;App. S2). ...
Remnant protected areas are essential for the survival of rainforest bird species within agricultural landscapes. The Lake Eacham section of Crater Lakes National Park on the Atherton Tablelands, Far North Queensland, is a 450 ha remnant of mid-altitude tropical rainforest in the Wet Tropics World Heritage Area, surrounding a 52 ha volcanic crater lake, and 3 km from intact forest. It has been 'hyper-disturbed' by edge effects and periodic tropical cyclones, and has high tourist visitation rates. From 1993-1998 a volunteer group, the Tablelands National Park Volunteers, conducted monthly bird surveys in three sites. These sites supported a significant rainforest avifauna, with 7,496 bird records of 87 species. Most birds were dependent or largely dependent on rainforest, including 28 Wet Tropics endemic species or subspecies of which four were rainforest obligates. Arboreal insectivores were most abundant, followed by disperser frugivores. Birds seen included nine threatened and four near threatened species. The suite of species at Lake Eacham was comparable with that found in nearby intact forest. We believe this important remnant should be resurveyed, as recent surveys in intact rainforest in the region have detected declines in a number of species including 17 that we recorded as common or abundant. Further, two severe tropical cyclones have impacted the Park since 1998 and Lake Eacham is central to two major revegetation linkage projects, the Peterson Creek and Lakes Corridors. As the volunteer group disbanded in 2016, we provide the complete data as a supplementary file, to give others the opportunity for resurvey.
... Most of the plant species in the study site are highly moisturedependent (Drake & Franks, 2003;Tracey, 1982). ...
Stable isotope studies (δ2H and δ18O) of water within plants are providing new information on water sources, competitive interactions and water use patterns under natural conditions. This is based on the assumption that there is no fractionation at the time of water uptake or during its transport within trees. However, previous studies have found fractionation does occur in water taken up through the roots in halophytic and xerophytic plants. It is unclear how widespread such fractionation is in other species. In this study, we tested this fractionation by comparing stem and branch xylem water isotopes over the period of one day (from 8am-5pm) in four wet tropical rainforest tree species (Dendrocnide photinophylla, Aphananthe philippinensis, Daphnandra repandula and Mallotus polyadenos).We found branch water isotope ratios (δ2H and δ18O) were enriched compared with stem xylem water isotopes. D. photinophylla had a significantly different branch δ18O ratio than A. philippinensis, D. repandula and M. polyadenos. In contrast, there were no significant differences in stem xylem δ18O among the four observed tree species.We found clear differences in the stable isotope ratios of δ18O for stem and branch xylem water for D. photinophylla and D. repandula of upto -0.85% and 0.50%, respectively. Remarkable δ2H differences were also found between stem and branch xylem water isotope ratios for A. philippinensis, D. repandula and M. polyadenos, being upto -12.14%, -16.17% and -9.65%, respectively. A Dual isotope (δ2H - δ18O) plot showed branch water values were more enriched than stem xylem water values for D. photinophylla and D. repandula, indicating a clear difference between stem and branch xylem water. This study suggests that δ2H and δ18O fractionation could be a species-specific phenomenon in tropical trees, which has important implications for plant water source identification and evapotranspiration partitioning.
... The soil in the Lake Barrine catchment derives from the pyroclastic and parent basaltic and metamorphic rocks and supports a slightly disturbed tropical rainforest with uneven canopy, classified as complex mesophyll vine forest (type 1b) (Tracey, 1982). The rainforest contains 430 species among which Podocarpus, Agathis, Eugenia, Elaeocarpus, Proteaceae and Cunoniaceae are important tree genera and families of the mature canopy (Chen, 1986). ...
Available online xxx Handling Editor: P Rioual Keywords: Paleoclimate change Northeastern Australia Bulk organic geochemistry m-XRF Maar lake sediment Deglacial Carbon isotope a b s t r a c t Lake Barrine (17.25 S, 145.64 E), on the Atherton Tablelands in tropical northeast Australia, was formed as a maar lake in the late Pleistocene. The 65 m-deep stratified lake provides a detailed sediment record of climate and environmental change on the Tablelands. We reconstruct hydroclimate and vegetation change over the last~18,000 years from a 7.2 m long sediment core at 20-year resolution using multiple paleoenvironmental proxies (m-XRF elements, d 13 C TOC , TOC and C:N ratio). The data series are supported by a chronology based on 22 accelerator mass spectrometer (AMS) radiocarbon dates. The results suggest a distinct period of intense but highly seasonal rainfall coincident with the Antarctic Cold Reversal (14.7 e13.0 cal ka BP). This period was followed by a trend into the early Holocene toward wetter, less seasonal conditions that allowed the progressive establishment of tropical forest in the catchment. The catchment was completely covered by closed forest by 7.3 cal ka BP. The inferred precipitation changes at Lake Barrine are consistent with other records on the Tablelands and in phase with the changes in tropical SE Africa, NW Australia and anti-phase with the East Asian summer monsoon region in the Holocene but not before that. This result supports previous conclusions that precipitation variations correlate (in phase or anti-phased) in these regions. This correlation results from a dynamic balance among intertropical convergence zone (ITCZ), the Indian Ocean Dipole (IOD) and El Niño Southern Oscillation (ENSO).
... Barron Gorge National Park comprises part of the Wet Tropics World Heritage Area of Australia (16.84 • S, 145.64 • E), whose listing was partially due to its recognition as a hotspot of plant and animal biodiversity. The vegetation community of the park, part of the traditional lands of the Djabugandji people (traditional owners), is composed of a closed-canopy mesophyll/notophyll vine forest (Tracey, 1982). ...
Lianas are increasing in abundance in many tropical forests. This increase can alter forest structure and decrease both carbon storage and tree diversity via antagonistic relationships between lianas and their host trees. Climate change is postulated as an underlying driver of increasing liana abundances, via increases in dry-season length, forest-disturbance events, and atmospheric CO2 concentrations; all factors thought to favour lianas. However, the impact of climate change on liana reproductive phenology, an underlying determinant of liana abundance, has been little studied, particularly outside of Neotropical forests. Over a 15-year period (2000–2014), we examined the phenological patterns of a liana community in intact rainforests of the Wet Tropics bioregion of Australia; a World Heritage Area and hotspot of floral diversity. Specifically, we assessed (1) flowering and fruiting patterns of liana species; (2) potential climate drivers of flowering and fruiting activity; and (3) the influence of El Niño-related climatic disturbances on liana phenology. We found that flowering and fruiting of the studied liana species increased over time. Liana reproduction, moreover, rose in apparent response to higher temperatures and reduced rainfall. Finally, we found flowering and fruiting of the liana species increased following El Niño events. These results suggest that liana reproduction and abundance are likely to increase under predicted future climate regimes, with potentially important impacts on the survival, growth, and reproduction of resident trees and thus the overall health of Australian tropical rainforests.
... The region encompasses a World Heritage Area with wide variety of tropical forest vegetation, primarily closed canopy evergreen wet forest (Goosem et al., 1999) developing under high rainfall in a coastal strip extending 450 km north from Cooktown to south in Townsville. In contrast, dry forests are restricted to inland enclaves under specific fire-protected settings and surrounded by savanna woodland (Tracey, 1982;Bowman, 2000;Neldner et al., 2019). ...
Forest tree species in wet and dry habitats are generally considered functionally divergent in leaf and stem functional traits such as leaf area, leaf mass per area, wood density and tree height. Yet, these traits have limited utility for characterizing plant water transport adaptations and strategies. We tested the hypothesis that wet and dry forest trees are functionally divergent in their water conducting apparatus. To assess trait differences and adaptations, we sampled branch wood from nine same-genus species-pairs, each species-pair occurring respectively in the wet (>1500 mm annual rainfall) and dry forest (<800 mm annual rainfall) in tropical Queensland, Australia. From branch wood sections, we measured anatomical traits involved in water conduction (stem vessel dimensions, fractions and their spatial distributions, theoretical water conductivities), storage (parenchyma), and providing hydraulic safety functions (fibres fractions, vulnerability index). Relative to wet forest species, we found on overall that dry forest trees had trait combinations showing adaptations to aridity such as more storage tissue and greater vessel connectivity which may provide alternative pathways for water transport should vessel embolism occur. Habitat is an environmental filter that influences trait behavior across related species. However, depending on the genera, species in both dry and wet forest habitats also exhibit various tradeoffs in trait values, highlighting the existence of diverse hydraulic strategies within wet forest and dry forest trees.
... The rainfall is highly seasonal with 66% falling between January and April, the wet season. The forest type at the site has a complex vertical profile, with canopy heights ranging from 24 to 33 m (Liddell et al., 2007), and a wide variety of plant lifeforms such as epiphytes, lianas, shrubs and herbs (Tracey, 1982). Soils are developed over metamorphic and granitic colluvium and are of relatively high fertility (Bass et al., 2011). ...
Tree saplings and shrubs are frequently overlooked components of tropical rainforest biodiversity, and it may be hypothesized that their small stature and shallow root systems predisposes them to be vulnerable to drought. However, these purported influences of drought on growth, physiological performance and plant traits on tree saplings and shrubs have yet to be studied in simulated drought conditions in the field. We simulated drought using a rainfall exclusion experiment in 0.4 ha of lowland tropical rainforest in northeast Australia in 2015. After six months, we compared the average change in aboveground biomass and plant health of drought-affected tree saplings and understory shrubs with control individuals. We also assessed photosynthetic function, plant health and leaf traits in eight target species. Both tree saplings and shrubs had significantly lower aboveground biomass in the drought treatment compared to the control. Drought-affected individuals of target species exhibited a significantly higher incidence of disease and insect attack, and reduced photosynthesis, leaf fresh mass and leaf toughness compared to control individuals. We conclude that reduced growth and photosynthetic capability, an increased susceptibility to insect attack, and leaf trait changes constitute a near immediate drought response in tropical rainforest tree saplings and shrubs. Our results show that these often-overlooked lifeforms are likely to be the most rapidly and negatively impacted component of tropical rainforest biodiversity under drought conditions.
... These forests can be complex, simple, evergreen, semi-evergreen and semi-deciduous and occur mostly from foothills to uplands. Trees have a canopy height of 24-33 m and communities occur generally on basalt and granite soils (Tracey, 1982). ...
Flower visitors use different parts of the landscape through the plants they visit, however these connections vary within and among land uses. Identifying which flower‐visiting insects are carrying pollen, and from where in the landscape, can elucidate key pollen–insect interactions and identify the most important sites for maintaining community‐level interactions across land uses. We developed a bipartite meta‐network, linking pollen–insect interactions with the sites they occur in. We used this to identify which land‐use types at the site‐ and landscape‐scale (within 500 m of a site) are most important for conserving pollen–insect interactions. We compared pollen–insect interactions across four different land uses (remnant native forest, avocado orchard, dairy farm, rotational potato crop) within a mosaic agricultural landscape. We sampled insects using flight intercept traps, identified pollen carried on their bodies and quantified distinct pollen–insect interactions that were highly specialized to both natural and modified land uses. We found that sites in crops and dairy farms had higher richness of pollen–insect interactions and higher interaction strength than small forest patches and orchards. Further, many interactions involved pollinator groups such as flies, wasps, and beetles that are often under‐represented in pollen–insect network studies, but were often connector species in our networks. These insect groups require greater attention to enable wholistic pollinator community conservation. Pollen samples were dominated by grass (Poaceae) pollen, indicating anemophilous plant species may provide important food resources for pollinators, particularly in modified land uses. Field‐scale land use (within 100 m of a site) better predicted pollen–insect interaction richness, uniqueness, and strength than landscape‐scale. Thus, management focused at smaller scales may provide more tractable outcomes for conserving or restoring pollen–insect interactions in modified landscapes. For instance, actions aimed at linking high‐richness sites with those containing unique (i.e., rare) interactions by enhancing floral corridors along field boundaries and between different land uses may best aid interaction diversity and connectance. The ability to map interactions across sites using a meta‐network approach is practical and can inform land‐use planning, whereby conservation efforts can be targeted toward areas that host key interactions between plant and pollinator species.
... These forest types support relatively high quality foliage (Martin, 2005). The Shipton's Flat site supports many of the same tree species as the 'mabi' forests of the Atherton Tablelands (Tracey, 1982), where Lumholtz's tree kangaroo is particularly abundant (Newell, 1999a, b). ...
The two Australian species of tree kangaroos are restricted to relatively small areas of rainforest in the wet tropics of north-east Queensland. Historical clearing for agriculture has removed extensive areas of high quality habitat for Lumholtz's tree kangaroo, but most remaining forests are protected in conservation reserves. The habitat of Bennett's tree kangaroo is largely intact. Traditional hunting may have exerted significant controls on the distribution of tree kangaroos, but neither species is currently hunted. Populations of Lumholtz's tree kangaroo inhabiting remnant forest on the Atherton Tableland are susceptible to vehicle-strike and dog attacks, but mortalities are < 1% of the estimated population. Climate change poses a potentially serious threat to Lumholtz's tree kangaroo, with a 2 °C increase in temperature predicted to reduce the extent of high quality habitat for this species by 75%. Impacts on Bennett's tree kangaroo are unknown. Our capacity to mitigate threats to the Australian tree kangaroos would be improved by the conduct of research on the ecological determinants of distribution and abundance, the study of thermoregulatory responses to increased temperatures, and studies to inform potential translocation of tree kangaroos to subtropical rainforests if required to conserve them in the face of climate change.
... The Daintree rainforest hosts the highest levels of floral endemism in Australia, and supports many near-basal angiosperm lineages (Metcalfe and Ford 2008). The forest of the DRO is classified as complex mesophyll vine forest (Tracey 1982), a type of rainforest common in protected areas of the Wet Tropics bioregion on soils of low to medium fertility. The climate in the Cape Tribulation area is humid tropical with a mean average temperature of 24.1°C and mean annual rainfall of 4403 mm year −1 during the study period. ...
Aims
Anthropogenic climate change is predicted to increase mean temperatures and rainfall seasonality. How tropical rainforest species will respond to this climate change remains uncertain. Here we analyzed the effects of a 4-year experimental throughfall exclusion on an Australian endemic palm (Normambya normanbyi) in the Daintree rainforest of North Queensland, Australia. We aimed to understand the impact of a simulated reduction in rainfall on the species’ physiological processes and fruiting phenology.
Methods
We examined the fruiting phenology and ecophysiology of this locally abundant palm to determine the ecological responses of the species to drought. Soil water availability was reduced overall by ~30% under a throughfall exclusion experiment (TFE), established in May 2015. We monitored monthly fruiting activity for 8 years in total (2009 - 2018), including four years prior to the onset of the TFE. In the most recent year of the study, we measured physiological parameters including photosynthetic rate, stomatal conductance and carbon stable isotopes (δ 13C, an integrated measure of water use efficiency) from young and mature leaves in both the dry and wet seasons.
Important Findings
We determined that the monthly fruiting activity of all palms was primarily driven by photoperiod, mean solar radiation and mean temperature. However, individuals exposed to lower soil moisture in the TFE decreased significantly in fruiting activity, photosynthetic rate and stomatal conductance. We found that these measures of physiological performance were affected by the TFE, season and the interaction of the two. Recovery of fruiting activity in the TFE palms was observed in 2018, when there was an increase in shallow soil moisture compared to previous years in the treatment. Our findings suggest that palms, such as the N. normanbyi, will be sensitive to future climate change with long-term monitoring recommended to determine population-scale impacts.
... One of these plots can be accessed by a 48.5 m high canopy-access crane (Leibherr Model 91EC, Adelaide, Australia). Forest at the DRO is described as a complex mesophyll vine forest Type 1a (Tracey, 1982) with a tall but irregular canopy varying in height from 25 to 33 m with indistinct stratification of the subcanopy. Within the crane plot are 85 canopy tree species (comprising 60 genera and 35 families) representing a basal area of ~33 m 2 ha -1 (Tng et al., 2016). ...
Premise:
Within closed-canopy forests, vertical gradients of light and atmospheric CO2 drive variations in leaf carbon isotope ratios, leaf mass per area (LMA), and the micromorphology of leaf epidermal cells. Variations in traits observed in preserved or fossilized leaves could enable inferences of past forest canopy closure and leaf function and thereby habitat of individual taxa. However, as yet no calibration study has examined how isotopic, micro- and macromorphological traits, in combination, reflect position within a modern closed-canopy forest or how these could be applied to the fossil record.
Methods:
Leaves were sampled from throughout the vertical profile of the tropical forest canopy using the 48.5 m crane at the Daintree Rainforest Observatory, Queensland, Australia. Carbon isotope ratios, LMA, petiole metric (i.e., petiole-width2 /leaf area, a proposed proxy for LMA that can be measured from fossil leaves), and leaf micromorphology (i.e., undulation index and cell area) were compared within species across a range of canopy positions, as quantified by leaf area index (LAI).
Results:
Individually, cell area, δ13 C, and petiole metric all correlated with both LAI and LMA, but the use of a combined model provided significantly greater predictive power.
Conclusions:
Using the observed relationships with leaf carbon isotope ratio and morphology to estimate the range of LAI in fossil floras can provide a measure of canopy closure in ancient forests. Similarly, estimates of LAI and LMA for individual taxa can provide comparative measures of light environment and growth strategy of fossil taxa from within a flora.
... It was also a response to current reports (e.g. Tracey, 1982) that approximately one-quarter of the total area of rainforest of northern Queensland had been cleared during the 20th century, mainly for intensive production, grazing and agriculture. ...
... In both regions, active beef-or dairy-cattle pasture sites located on previously rainforest-covered land were used as the 'pre-existing condition'. In the tropics, intact rainforest reference sites (representing the 'target') were located in complex notophyll or mesophyll vine forest (Tracey, 1982). Three sites were located near the margin of extensive rainforest (contiguous with rainforest > 100,000 ha in extent) and seven were in remnants 40-400 ha in size. ...
Decline in rainforest cover in many areas ofAustralia is being countered by various methods of forest reestablishment, including ecological restoration plantings, timber plantations, and unmanaged regrowth.We used assemblages of soil- and litter- dwelling mites to determine which style most closely recaptures the assemblage structure of mites associated with intact rainforest at 84 tropical and subtropical sites in eastern Australia. The six habitat types surveyed were pasture (the typical ‘pre-restoration’ state), unmanaged regrowth, monoculture forestry, multi-species forestry, ecological restoration and intact rainforest (the ‘target’state). Forestry and ecological restoration sites were 5–20 years old.Mites were extracted fromsoil/litter samples and (excluding Oribatida) identified to family or to finer levels. For two diverse but taxonomically difficult superfamilies characteristic of rainforest,Uropodoidea and Trombidioidea, identificationwas tomorphotaxon. Presence/absence data were analyzed in several ways. First, we used our data to create a list of ‘indicator taxa’ for pasture and rainforest, and determined the abundance of these indicators in each of the four reforestationmethods.We also calculatedmorphotaxon richness for uropodoids and trombidioids and compared these values among habitat types. In both of these analyses, ecological restoration was most similar to rainforest.We used ordination andANOSIM to compare mite assemblages among habitattypes. Althoughmite assemblages clearly distinguished between rainforest and pasture sites, they did not identify any of the four reforestation methods as being consistently similar to rainforest. They did, however, indicate that monoculture forestry and multi-species forestry plantations were often not readily distinguishable from pasture. This may have as much to do with silviculturalmethods common to these plantations (e.g., pruning, herbicide application, andmaintenance of a relatively open canopy) as to the low diversity of trees present in plantations. We conclude with a brief discussion of the utility of mites in rapid bioassessment programs in Australia, and suggest that the most pragmatic approach involves focusing on a few easily recognized indicators rather than on entire assemblages.
... Nutrient concentrations in the stream are typically very low (Connolly & Pearson, 2013). Vegetation within the catchment is primarily simple notophyll vine forest (Tracey, 1982), with complex notophyll vine forest close to the stream (Webb, 1978). ...
Headwater streams drain large proportions of landscapes and represent a large proportion of stream habitat. Understanding their ecology requires more comparative data from the smallest streams. We describe dynamics of benthic organic material (BOM) and invertebrate assemblages in an order-2 Australian tropical stream and compare samples from orders-1 and 2 sites. Litterfall and, especially, stream discharge determined BOM standing stock. Most material was in the > 1 mm fraction, pools stored more than riffles, and order-1 sites more than order-2. BOM increased in the dry season but was depleted by wet-season spates. Retention was greater in years without major spates, when riffle-pool stream sections were largely ecologically isolated. Invertebrate richness was greater in riffles than pools and in order-2 than order-1 sites, with overlap in composition. Current velocity was the primary variable determining distributions in order-2 sites, with particulate organic matter (63–250 µm) the main variable in order-1 sites. However, explanatory relationships were weak because of unusually benign conditions during the sampling period. We need more globally comprehensive spatially explicit assessment of the ecosystem dynamics of headwater streams to predict effects of environmental change. Assessments over extended periods are necessary to capture the variability of even apparently predictable systems.
... Using aerial photos combined with records of early land use, Hill et al. (2000) argued that management of fire by the Kuku-Yalanji people prior to European occupation ensured the presence of extensive rainforest cover, and that current rainforest expansion in her study region represents recovery from logging. The regeneration from logging hypothesis is also highly likely for upland rainforest, given an estimate of more than 40% of the original area of rainforest on the Tablelands at the time of contact in the late nineteenth century had been cleared, mainly for cane farming and cattle grazing (Tracey 1982). ...
Australian tall eucalypt forests have been the subject of awe and admiration since early colonial days. In the Wet Tropics of North Queensland, such forest occurs in transitional or ecotonal patches between rainforests and open woodland savannas. Rainforest species are commonly interpreted to be encroaching into the understorey of these tall eucalypt forests, namely those with statuesque Rose Gum (Eucalyptus grandis) dominants. This has led to concerns for the long term persistence of E. grandis forests, and ongoing debates over their need for active fire management. In this essay, I highlight the enigmatic ecology of these ecotonal forest habitats, and make the case that the management of these habitats should be grounded in ecological principles within a broader perspective of patterns in global vegetation change.
Citation: Tng DYP. 2019. The enigma of Eucalyptus grandis(Rose Gum)/rainforest ecotones in the Australian Wet Tropics –the plot thickens. North Queensland Naturalist 49: 25-33.
... The study was undertaken on the Thiaki Creek Nature Reserve (Fig. 1), located on the southern Atherton Tablelands in far North Queensland, Australia (145°51 0 E 17°43 0 S), between 900 and 1000 m elevation. The topography comprises narrow valleys surrounded by 15-45°slopes, with an underlying basaltic substrate (Tracey 1982). The region has distinct wet (November-April) and dry (May-October) seasons, with an annual rainfall of 1940 mm (Cheesman et al. 2018). ...
Central to the success of restoration plantings within abandoned pastures is the appropriate selection of species that can establish and grow rapidly to form canopies to suppress grasses. However, species selection can be difficult, largely due to combinations of biotic and abiotic factors operating across multiple spatial scales that can affect seedling growth rates. Using a large replicated restoration experiment in Australia's Wet Tropics, we evaluated seedling growth rates of 24 native rainforest species commonly used in local restoration efforts over the first 31 months post-planting. We investigated the influence of landscape, site, and planting conditions on early-stage seedling growth and whether functional traits and surrounding neighborhood density and composition explain variation in seedling growth rates. Seedling growth rates were influenced by numerous stem-, species-, plot-, and climate-level factors, with the strength of these effects strongly dependent on the size of the seedling. Specifically, species with low wood densities and larger seeds grew faster. In response to plot-scale and climate factors, larger seedlings consistently displayed faster growth, demonstrating the benefits of initial seedling size for seedling success. Our study highlights that early-stage seedling growth can be influenced by many factors, operating across multiple spatial scales. Importantly, we demonstrate that planting larger seedlings may improve seedling growth and that developing strategies to increase the survival of fast-growing low wood density species is crucial for ensuring that plantings can achieve canopy closure quickly, improving early to mid-term trajec-tories of tropical forest recovery.
... While not all the specimens were sectioned, all of the specimens have tessellated, vertically-orientated, fissured bark, and have evidence of stratified secondary phloem and one stem (QMF58858) has a diameter of over four centimeters, and hence Austrovideira were relatively large, robust lianas. As many of fossil plants at the Capella site belong to, or are considered closely related to, genera that have species with relatively large leaves, e.g., Athertonia, Elaeocarpus, Fontainea and Pleiogynium the Capella forest is interpreted as a complex mesophyllnotophyll rainforest (sensu Webb & Tracey, 1981;Tracey, 1982) with lianas (Menispermaceae and Vitaceae). The presence of conifer wood suggests a canopy of emergent conifers, as they are reliant upon wind dispersal of their pollen. ...
Austrovideira dettmannae gen. & sp. nov. from the early Oligocene Capella Flora in central Queensland is the first fossil Vitaceae wood described from the Southern Hemisphere. A new combination, Stafylioxylon ramunculiformis (Poole and Wilkinson) Pace and Rozefelds for a Northern Hemisphere fossil wood is also proposed. Austrovideira and Stafylioxylon share with Vitaceoxylon secondary xylem with two diameter classes of vessels, wide vessels usually solitary, narrow vessels forming radial chains, very wide and tall rays, scanty paratracheal parenchyma and septate fibres. Austrovideira differs from Vitaceoxylon in having scalariform intervessel pits and homocellular rays composed exclusively of procumbent cells. This combination of features is seen in the Ampelocissus-Vitis clade, and a clearly stratified phloem with fibre bands alternating with all other axial elements and phloem rays rapidly dilating towards the periderm is restricted to Parthenocissus and Vitis. Stafylioxylon shares with Austrovideira the presence of scalariform intervessel pits but it differs from that genus in both ray composition and bark anatomy, as it lacks a stratified phloem. These fossil wood genera demonstrate that the lianescent habit in the Vitaceae was established by the Eocene in the Northern Hemisphere and by the Oligocene in the Southern Hemisphere. The pollen and seed fossil record shows that the Vitaceae were in Australia by the Eocene and fossil seeds suggest that the family had radiated by this time. The Oligocene Capella flora with two seed taxa and fossil wood (Austrovideira) provides further evidence of an Australian radiation. The fossil evidence, suggests a significant Gondwanic history for the family.
... A narrow band of tall open forest exists on the upland western margins of rainforest in the Wet Tropics region. This is vegetation Type 14 (Tracey and Webb 1975;Tracey 1982), which towards the wetter side of the band becomes Types 14a and 14b, also referred to as wet sclerophyll forest. It probably presents the greatest management challenge for forest fauna conservation in north Queensland. ...
... The study streams were perennial and flowed through closed rainforest ("simple notophyll vine forest"; Tracey, 1982). Six riffles and six pools were sampled in each of the study areas (Paluma and Tully). ...
Tadpoles can be abundant consumers in stream ecosystems, and may influence the structure and function of streams through their feeding activities and interactions with other organisms. To understand the contribution of tadpoles to stream functioning, and the potential impact of their loss, it is necessary to determine their diets and how they might influence food‐web structure.
Using gut‐content analysis and stable‐isotope analysis of N and C, we determined the main food sources and trophic positions of tadpoles of five native frog species, invertebrates, and fish in upland and lowland Australian Wet Tropics streams.
Omnivory was prevalent among the tadpoles and invertebrates. Tadpoles consumed different food according to availability and nutrient quality, but assimilated mainly biofilm and algae. Most tadpoles and invertebrates assimilated the same high‐quality foods.
Food webs in upland riffles were simplified by local extinction of tadpoles, and were probably simplified in pools in the cooler months by seasonal decline in tadpole abundance. Food‐web complexity was increased in some pools by the presence of predatory fish and a greater number of basal sources.
As tadpoles are important seasonal components in stream food webs, their local extinction can greatly alter food‐web structure and complexity and, possibly, processes such as leaf litter breakdown and sediment accumulation.
... This study was undertaken on the Thiaki Creek Nature Reserve (Fig. 1), located on the southern Atherton Tablelands of far North Queensland, Australia (145°51'E 17°43'S), between 900 and 1000 m elevation, with an average annual rainfall of 1400 mm (Bell et al., 1987). The underlying substrate is basaltic (Tracey, 1982) with a varied topography of narrow valleys surrounded by 15° to 45° slopes. The 181 ha reserve comprises 130 ha of primary and mature secondary rainforest, classified as Endangered Regional Ecosystem 7.8.4, ...
The success of restoration projects is known to vary widely, with outcomes relating to numerous biotic and abiotic factors. Though many studies have examined the factors associated with long‐term restoration success, few have examined which factors impact the establishment of restoration plantings.
In Australia's Wet Tropics, we used a large replicated restoration experiment to assess seedling survival for 24 native rainforest species commonly used in local restoration efforts. The experiment allowed for a rigorous assessment of the effects of species functional traits, planting conditions, and landscape‐ and local‐scale biotic and abiotic factors on seedling survival. This study reports on seedling survival between three different time periods of 0–4, 4–9 and 9–31 months post planting.
The probability of seedling survival was influenced by multiple factors, varying in importance over time. Across the whole study period, seedlings with high wood density and which were planted closer to intact forest consistently displayed the highest probabilities of survival. Transient factors affecting seedling survival across the three time periods included plot aspect (0–4 months only), the identity of the planter and slope (4–9 and 9–31 months). Overall, species survival did not differ between the low (6 species) and high (24 species) diversity treatments, but was significantly lower in monocultures of Flindersia brayleyana by the end of the study.
We demonstrate that early‐stage seedling survival depends on species wood density and planting location. Our results support the use of species with more conservative growth strategies when limited funds are available for follow‐up plantings. High wood density species had significantly higher survival than lower wood density, early successional species typically used in rainforest restoration plantings.
Synthesis and applications . Our study highlights the importance of wood density and landscape structure to the initial survival of rainforest plantings. Factors influencing seedling survival shifted over time but, most importantly, our results highlight that, when planting into abandoned pastures, it may be preferable to select species with higher wood densities to maximize survival during the crucial early stages of establishment and growth.
Globally, invasive species, climate change and increasing tourism are currently recognised as the three most significant threats to Outstanding Universal Values of natural World Heritage listed Areas. This study investigated the threat of incursion of invasive plant species associated with access roads in the Wet Tropics World Heritage Area in Queensland, Australia. We assessed species richness, abundance, and the spread of non-native plant species along roads and in the adjacent vegetation using 306 1m² quadrats along 34 transects first sampled in 2015 and resampled in 2021. Plant species and vegetation cover of all ground-layer plants were recorded. Thirty-one non-native plant species were recorded, and their richness was found to be significantly higher at the road edge (27 species) than in the adjacent vegetation (16 species). Non-native plant species richness and cover decreased with distance from the road edge, in contrast to that of native plants which showed an increase. Many significant associations were detected including those between non-native plant cover, non-native species richness, native plant cover, plant litter cover, forest canopy cover, bare ground, rock and stones cover, and time since last fire (P < 0.05). Vegetation cover for more than 73% of the recorded non-native species at the road edge was < 5%. The large number of non-native species and the potential for a small set of these species to dominate the road edge and spread into the adjoining environment, highlights the need to mitigate the impacts of linear infrastructure development in protected areas, and the importance of timely surveillance and targeted control of non-native plants at road edges to avoid their spread into the adjacent vegetation.
An observation of birds, lizards, and fish feeding on swarming termite alates (Termes sp.) in tropical rainforest is described.
This datasheet on Albizia procera covers Identity, Overview, Distribution, Dispersal, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Management, Genetics and Breeding, Economics, Further Information.
This datasheet on Acacia mangium covers Identity, Overview, Associated Diseases, Pests or Pathogens, Distribution, Dispersal, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Management, Genetics and Breeding, Economics, Further Information.
The aerial micro-habitats created by bird’s-nest ferns provide invertebrate habitats that are distinct from the forest-floor environment, and they contribute to the biological diversity of tropical and subtropical forests. In this study, we set up and surveyed a 3.84-ha sample area in the Fushan Forest Dynamics Plot, which is located in a subtropical moist forest in northern Taiwan. We analyzed the spatial distributions of 2 native bird’s-nest ferns, Asplenium antiquum and A. nidus, to explore how topography and structural factors of host trees, which strongly affect the light conditions and water availability, shape the spatial distributions of these 2 species. The distributions of these 2 bird’s-nest ferns were mostly concentrated in downhill areas and near creeks with higher water availability. In terms of the epiphytic locations on host trees, the 2 bird’s-nest ferns were mostly attached to the trunk
of host trees rather than to the branches in the canopy. The epiphytic height of both species was concentrated at 2~4 m above the ground, and they rarely grew at a height of >10 m above the ground. The spatial distribution characteristics of A. antiquum and A. nidus were similar. Even in the Fushan subtropical humid forest where drought events are rare, A. antiquum and A. nidus were mostly distributed in downhill areas and near creeks with relatively high water availability and on the lower trunks of host trees with low light levels. The roles of photosynthesis, water physiological characteristics, and typhoon disturbances to the forest canopy in affecting the spatial patterns of bird’s-nest ferns in this subtropical moist forest are also discussed.
Context Transdisciplinary research is important where information from multiple fields is required to develop ecologically and culturally appropriate environmental planning that protects local conservation and socio-cultural values.
Objectives Here, we describe research to inform ecosystem restoration and conservation of Chumbrumba Swamp within the Wet Tropics World Heritage Area, Australia. Many such open wetlands in the region have been degraded through agriculture and pastoral production, but there has been little research into their status, history and conservation needs.
Methods The recent to pre-European settlement history of the site was explored, along with spatial variation of vegetation communities at the site, and these data integrated with historical and ethnographical information on the site and its cultural values.
Results The botanical and palaeoecological analyses showed that Chumbrumba Swamp comprises a unique and highly sensitive ecosystem mosaic with high biodiversity. An endangered ecosystem complex, 82 vascular plant species, several disjunct or endemic taxa, and species at new northern range limits were recorded within its 20 ha area. The site comprises a stable swamp site with fringing woodland and rainforest that has persisted for around 5000 years. European settlement overlaid changes in the vegetation from disturbance (e.g. fire, clearing, grazing). However, fire also affected the swamp site during pre-European times.
Conclusions Historical and ethnographic information contextualised the biophysical data and confirmed the cultural importance of the site and the dynamic interactions between ‘people and nature’. These results have been used to inform environmental restoration and validate the importance of a transdisciplinary and precautionary approach to planning wetland restoration and conservation.
Lianas are an important component of tropical forests; they alter tree mortality and recruitment and impact biogeochemical cycling. Recent evidence suggests that the abundance of lianas in tropical forests is increasing. To understand and predict the effect of lianas on ecosystem processes in tropical forests, it is important to understand the mechanisms through which they compete with trees. In this study, we investigated the functional traits of lianas and trees in a lowland tropical forest in northeast Queensland, Australia. The site is located at 16.1° south latitude and experiences significant seasonality in rainfall, with pronounced wet and dry seasons. It is also subject to relatively frequent disturbance by cyclones. We asked the question of whether the canopy liana community at this site would display functional traits consistent with a competitive advantage over trees in response to disturbance, or in response to dry season water stress. We found that traits that we considered indicative of a dry season advantage (xylem water δ¹⁸O as an indicator of rooting depth; leaf and stem tissue δ¹³C and instantaneous gas exchange as measures of water‐use efficiency) did not differ between canopy lianas and canopy trees. On the other hand, lianas differed from trees in traits that should confer an advantage in response to disturbance (low wood density; low leaf dry matter content; high leaf N concentration; high mass‐based photosynthetic rates). We conclude that the liana community at the study site expressed functional traits geared towards rapid resource acquisition and growth in response to disturbance, rather than outcompeting trees during periods of water stress. These results contribute to a body of literature which will be useful for parameterising a liana functional type in ecosystem models.
Lianas (woody climbers) are structural parasites of trees that compete with them for light and below-ground resources. Most studies of liana–tree interactions are based on ground-level observations of liana stem density and size, with these assessments generally assumed to reflect the amount of liana canopy cover and overall burden to the tree. We tested this assumption in a 1-ha plot of lowland rainforest in tropical Australia. We recorded 1072 liana stems (≥1 cm diameter at breast height {dbh}) ha ⁻¹ across all trees (≥10 cm dbh) on the plot and selected 58 trees for detailed study. We estimated liana canopy cover on selected trees that hosted 0–15 liana individuals, using a 47-m-tall canopy crane. Notably, we found no significant correlations between liana canopy cover and three commonly used ground-based measurements of liana abundance as follows: liana stem counts per tree, liana above-ground biomass per tree and liana basal area per tree. We also explored the role of tree size and liana infestation and found that larger trees (≥20 cm dbh) were more likely to support lianas and to host more liana stems than smaller trees (≤20 cm dbh). This pattern of liana stem density, however, did not correlate with greater liana coverage in the canopy. Tree family was also found to have a significant effect on likelihood of hosting lianas, with trees in some families 3–4 times more likely to host a liana than other families. We suggest that local ground-based measures of liana–tree infestation may not accurately reflect liana canopy cover for individual trees because they were frequently observed spreading through neighbouring trees at our site. We believe that future liana research will benefit from new technologies such as high-quality aerial photography taken from drones when the aim is to detect the relative burden of lianas on individual trees.
The State of Queensland in northeast Australia covers 1.73 million square kilometres and encompasses a wide variety of landscapes across temperate, wet and dry tropics and semi-arid to arid climatic zones. Currently (January 2019), 1424 regional ecosystems are recognised across Queensland. Regional ecosystems are defined and mapped at 1:100,000 scale across the state. Many regional ecosystems include one or more vegetation communities, some of which are only recognised and mapped at scales larger than 1:100,000. A vegetation community is an association within a regional ecosystem that has similar structure and floristics and occurs within the same land zone.
Broad Vegetation Groups (BVGs) are a higher-level grouping of vegetation communities and regional ecosystems. BVGs provide an overview of vegetation across the state or a bioregion. They are a useful addition to the regional ecosystem framework by providing an overview of major ecological patterns and relationships across Queensland, independent of bioregions and land zones, and facilitate comparisons with vegetation in other states and internationally. The primary aim of this document is to concisely describe the BVGs of Queensland to enhance their use in government planning, policy and regulation, e.g. vegetation offsets, Bushfire Hazard Area mapping, public education and scientific investigations.
Floristic, structural, functional, biogeographic and landscape attributes have all been used in the BVG classification. The first aggregation of BVGs in the hierarchical classification is determined on the basis of vegetation structure (cover, height and growth form) of the ecologically dominant layer. BVGs are ordered broadly to reflect the vegetation structure along a mesic gradient from wet closed forests (rainforests) of the coast and north east, to the arid spinifex hummock grasslands of the south west. Specialised habitats such as freshwater wetlands (BVG 34) and intertidal areas (BVG 35) form the final groups. The rainforest aggregation (BVGs 1-7) are characterised by a generally closed tree canopy, predominantly non-sclerophyllous plants and frequently specialised lifeforms. The large aggregation of BVGs dominated by eucalypts (BVGs 8-19) is further subdivided on the basis of structure, mesic situation, landscape situation, predominant geology and dominant/ diagnostic species. The third aggregation of BVGs is dominated by trees or tall shrubs that are not eucalypts or rainforest species. Some BVGs in this aggregation are generally dominated by a single species, e.g. Melaleuca viridiflora (BVG 21a), or a group of taxonomically and functionally related species, e.g. Acacia cambagei/ A. georginae/ A. argyrodendron (BVG 26a), or by a combination of a structural formation, habitat and functionally related species such as low open woodlands on sand plains (BVG 27b).
The final aggregation of BVGs is those not dominated by trees or tall shrubs. Some BVGs in this aggregation encompass vegetation types that are generally dominated by a suite of taxonomically and functionally related species, such as Acacia spp. on residuals (BVG 24a) or Senna spp. (e.g. BVG 24b). Other groups are dominated by a distinct structural formation (such as tussock and closed tussock grasslands BVGs 30-32).
The Vegetation of Queensland describes the 98 BVGs defined for the 1:1M mapping level and lists the most extensive regional ecosystems in each BVG. The document is illustrated with 375 photographs, 108 tables and 103 maps, with detailed pre-clearing and remnant extent, and extent within the protected area estate. There are three nested levels of BVG which reflect the approximate scale at which they are designed to be used: the 1:1,000,000 (regional) (98 BVGs), 1:2,000,000 (state) (35 BVGs) and 1:5,000,000 (national) (16 BVGs). Links are provided to more detailed information and online regional ecosystem mapping.
A new density gradient method for the extraction of spores of putative ectomycorrhizal fungi from scats of Uromys caudimaculatus (white tailed rat) (Muridae) was compared to two commonly employed methods, sieving and maceration. The study demonstrated this new method to be superior both quantitatively and qualitatively to the sieving and maceration methods. All three extraction methods were effective in recovering a variety of morphologically different spores from the scat. All taxa found were recovered by all of the three methods. However, the sieving and maceration methods required 3 X and 5 X the number of grids counted, respectively, to recover the same number of taxa as the density gradient method. The methods also differed significantly in the number of spores recovered. The new density gradient method recovered an average of 3 X, and 13 X, the number of spores recovered by the sieving and maceration methods, respectively. It is suggested that this method is not only suitable for spore enumeration work, but is a nondestructive efficient technique for concentration of spores.
Determining if the seasonality of leaf litter invertebrate populations in tropical rainforests is driven by climate or availability of litter, or both, is important to more accurately predict the vulnerability of litter invertebrates to climate change. Here we used two approaches to disentangle these effects. First, the influence of climatic seasonality was quantified by sampling a fixed volume of litter monthly over 4 years and counting extracted beetles and ants. Second, litter volume was experimentally manipulated (addition and exclusion) to test the influence of litter quantity independently of climatic variation. There were significant seasonal peaks for both beetle and ant abundance and these were positively correlated with rainfall, temperature and litter volume. As abundance was measured on a ‘per litter volume’ basis we conclude that there was a significant effect of climate on abundance. The litter manipulation experiment showed that beetle and ant abundance per litter volume were also influenced by litter volume, when it was low. We recognise that other factors such as litter structure or complexity may have affected temporal ant abundance. Beetle and ant abundance were depressed in litter exclusion plots but did not differ significantly between control and addition plots, suggesting a possible ceiling in the effect of litter volume on population sizes. We conclude that seasonality in climate and litter quantity are driving most temporal variation in insect abundance and that there may be some resilience among leaf litter insects to cope with higher temperatures. However, future responses by plants to increased climatic variability and higher CO2 concentrations may alter litter fall dynamics and thus temporal patterns in litter insect abundances.
Microclimatic conditions have a strong influence on the distribution of vascular epiphytes, among which orchids often occur in sunnier and more drought-prone situations than ferns. However, very few studies have looked at the distribution of ferns and orchids in Australian tropical rainforests. By using transmitted light measurements at the locations of individual epiphytes and vapour pressure deficit from the canopy and base of host trees, we were able to determine the patterns of light and humidity in the rainforest environment, and the responses of ferns and orchids to variation in the physical environments. We surveyed five sites, ranging from 800 to 1180 m in elevation in the lower montane rainforests of north-east Australia. Data loggers recorded the vapour pressure deficit (VPD) at the forest floor and canopy of each site. Light was correlated with height within the host tree and VPD differed significantly over position in the host tree and elevation. There was a strong partitioning of taxonomic groups over the light and VPD gradients. Orchids occurred in environments that had higher mean light levels and mean daily maximum VPD (27% and 0.43 kPa, respectively) than ferns (21% and 0.28 kPa). There was also strong microclimatic partitioning of species within taxonomic groups, suggesting that microclimatic factors play an important role in the realized niche spaces of epiphytes within the tropical Australian rainforest. Thus, the tested ecological generalizations made on tropical rainforest epiphytes apply in Australia.
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