Table 1 - uploaded by Douglas Euston-Brown
Content may be subject to copyright.
Similar publications
Identifying the environmental factors that shape intraspecific genetic and phenotypic diversity of species can provide insights into the processes that generate and maintain divergence in highly diverse biomes such as the savannas of the Neotropics. Here, we sampled Qualea grandiflora, the most widely distributed tree species in the Cerrado, a larg...
Citations
... e. cleared and sown/unsown), only invasive vegetation was removed within the plots once during 2016, including roots and surface litter (which would contain seeds). The removal of all invasive vegetation was carried out following the South African savanna weed-clearing protocols outlined by Euston-Brown et al. (2007), namely hand-pulling for smaller plants and seedlings, and the use of weeding forks for larger plants (>0.5 m). Cleared only plots had the soil lightly raked and compacted manually, using a rubber ground rammer (tamper) after clearing. ...
The annual herb Parthenium hysterophorus L. (Asteraceae), remains one of Southern Africa's most significant invasive weeds, commonly invading savannas, and their rangelands, causing severe losses to agriculture, livestock production and native biodiversity. Previous studies have suggested that perennial grasses may act as useful competitive species, capable of suppressing the growth and invasion of P. hysterophorus. To explore this, a total of 48 plots were established within an invaded savanna, using a randomised block design, and included treatments with and without the clearing of P. hysterophorus, as well as with and without the sowing of native perennial grass seed (Anthephora pubescens, Chloris gayana, Cynodon dactylon, Digitaria eriantha, Eragrostis curvula, Panicum maximum and Themeda triandra). Plots were assessed yearly in terms of P. hysterophorus density and growth as well as grass species composition, basal cover, and biomass over a three-year period. Clearing alone was found to exacerbate invasion, increasing P. hysterophorus density by 40%. Whereas the sowing of grass seed, in both the cleared and uncleared plots, increased the abundance of perennial grass species by 28%, subsequently reducing the size, reproductive output and density of P. hysterophorus over the three years. In addition, these sowing efforts contributed towards partial restoration of the plots, enhancing grass basal cover by ~15% and biomass production by 17%. Overall, this research suggests that sowing of native grass species, with or without clearing, may be a useful supplementary control or restoration tool towards the long-term management of P. hysterophorus invasions in managed savannas and rangelands in Southern Africa.
... get species, the likelihood of non-target impacts on site and environmental conditions(Euston-Brown, Rathogwa, & Richardson, 2007).Richardson et al. (2007) suggest several non-chemical control strategies (such as control of regenerating aliens, clearing alien stands, introduce biological control, fire and grazing) as main management actions to facilitate restoration of riparian plant communities. ...
Invasive plant species can hinder the establishment and growth of native plants and impact several ecosystem properties, such as soil cover, nutrient cycling, fire regimes and hydrology. Controlling invasive plants is then a necessary, yet usually expensive, step towards the restoration of an ecosystem. A synthesis of literature is needed to understand variation in invasive plants' impacts and their practical control in restoration contexts, and to identify associated knowledge gaps.
We reviewed 372 articles published from 2000 to 2019 covering the control of undesirable plants (both exotic invasive and overabundant native plant species) in ecological restoration to gather information on the main plants being controlled and methods used, and considering the distribution of studies among biomes and countries grouped according to the Human Development Index (HDI).
Grasses and forbs were the most‐studied invasive plant species in restoration sites, but invasive trees were well studied in the tropics. Poaceae and Asteraceae were the most studied families of invasive plants. Non‐chemical interventions (mostly mowing and prescribed fire) were used in more than half of the reviewed studies globally, but chemical methods (mainly glyphosate spraying, used in 40% of projects using herbicides) are also common. The reviewed studies were mostly performed in countries with very high HDI. Countries with low and medium HDI used only non‐chemical methods.
Synthesis and applications. Decisions about which control method to use depend heavily on the invasive plant species' growth forms, the local economic situation where the restoration sites are located and resources available for control. More developed countries tend to use more chemical control, whereas less developed ones use mainly non‐chemical methods. Since most of the reviewed studies were performed in countries with very high HDI, we lack information from developing countries, which concentrates global hotspots for biodiversity conservation and global commitments of forest and landscape restoration.
... Lantana camara L. biological attributes like high number of production of fruits each year (prolific seed production) (Mack et al., 2000) and duration of fruit production (which is throughout the year when conditions are favorable such as adequate light and moisture) (Gentle & Duggin, 1998;Euston-Brown et al., 2007;Gujral & Vasudevan, 1983), its ability to propagate vegetatively by a process called layering where horizontal stems take root when they are in contact with moist soil (Priyanka & Joshi, 2013;Walton, 2006), ability of the weed seeds to germinate at any time of the year and the seed viability for longer periods ranging from 2-5 years (Wijayabandara et al., 2011), better competitive ability compared to native flora, widespread geographic range (wide ecological tolerance) (Sharma et al., 2005;Day et al., 2003) contributed to the success of its dispersal. The ability of Lantana camara L. to rapidly colonize areas of land which have been disturbed (in countries like Ethiopia where activities such as logging and clearance for agriculture are common) may allow its dispersal too (FEPPC, 2005). ...
Lantana camara L. is one of the worst invasive alien species that are categorized worldwide. The objective of this review paper was to review the dispersal and threats posed by Lantana camara L. in Ethiopia and based on review results, to suggest management strategies that can bring solutions to the threats posed by the weed. Both biological characteristics of Lantana camara L. and its dispersal agents have contributed to the success of its dispersal. Even though Lantana camara L. is dispersed in other places within Ethiopia, Debrezeit, Dire Dawa, Harar and Somali are the hotspot areas for the weed. Biodiversity and potential agricultural loss, human and animal health problems and infestation in national parks are the identified threats that Lantana camara L. posed within the country. Utilization of Lantana camara L. for various purposes, prevention of its further dispersal into non-infected areas, use of fire, mechanical and biological control and awareness creation are the suggested management strategies that can bring solutions to the threats posed by the weed within the country.
... The main clearing practice utilized to control C. odorata is known as cut-stump treatment, i.e. slashing followed immediately with a treatment of herbicide to the remaining stump (Euston-Brown et al., 2007). Small plants are generally hand-pulled (Van Gils et al., 2004;Euston-Brown et al., 2007). ...
... The main clearing practice utilized to control C. odorata is known as cut-stump treatment, i.e. slashing followed immediately with a treatment of herbicide to the remaining stump (Euston-Brown et al., 2007). Small plants are generally hand-pulled (Van Gils et al., 2004;Euston-Brown et al., 2007). Due to the rapid regenerative properties of the plant, cut-stump treatment always needs to be followed-up several times. ...
Biological invasions have increased dramatically in the past centuries and are one of the greatest threats to biodiversity today. Chromolaena odorata, a herbaceous shrub from the Americas, is one of the most widespread and problematic invasive plant species in the tropics and sub-tropics. The plant is a serious problem in South Africa, where invasive species threaten biodiversity and use up water resources. This study combines data on the distribution of C. odorata with ecological and clearing management data to evaluate the efficacy of an invasive plant clearing program over its decade of operation in the Hluhluwe-iMfolozi Park in KwaZulu-Natal, South Africa. Densities and local extent of the C. odorata invasion were significantly reduced during the period of operations of the clearing program. Seasonal effects impacted clearing efficacy, namely a reduction in efficacy during the seed dispersal period. Clearing success was positively associated with clearing effort and fire frequency and negatively associated with rainfall. Management implications drawn from the results include halting clearing during the seed-drop period, giving extra attention to areas with more rainfall and other water availability, and incorporating fire with other clearing methods where possible.
... 1. These include prolific flowering and production of fleshy fruit throughout the year (Euston-Brown et al., 2007; Gujral and Vasudevan, 1983), features that are particularly important as frugivorous birds are important dispersal vectors. Endozoochory (i.e. the dispersal of seeds after passage through the vertebrate gut) has been shown to increase seed germination rates and vigor (Jordaan et al., 2011). ...
... Over the last two decades, the potential of fungal pathogens as control agents has also been explored, and in 2001 permission was granted to release the leaf-spot fungus Passalora lantanae Chupp (formerly in Mycovellosiella), collected from Florida, USA (Den Breeÿen and Morris, 2003). It was released in the Eastern Cape, KwaZulu-Natal and Mpumalanga (Euston-Brown et al., 2007), but failed to establish (Retief, 2010). Other pathogens currently under investigation include Septoria sp. and Puccinia lantanae Farlow (Klein, 2011). ...
... Mechanical control methods used in WfW projects involve slashing and sometimes scraping by bulldozing. In areas with limited invasions, hand pulling of seedlings is employed (Euston-Brown et al., 2007). At least 11 herbicides are registered for use on L. camara in South Africa (see Brown et al., 2007). ...
Lantana camara L. (sensu lato) has a wide range of impacts throughout its global invasive range. Here we review the mechanisms driving its invasion dynamics in South Africa at national (biome, habitat) and regional (within a protected area) scales. Although only three introduction events into South Africa have been recorded (the earliest in 1858), as of 1998 L. camara was found in over 2 million ha (total area), with a condensed area of about 70,000 ha. Moreover, L. camara is present in most of the country's major biomes and a diversity of habitats, confirming its broad ecological tolerance. Using correlative bioclimatic models, we show that under future climate conditions, L. camara's range in South Africa could expand considerably over the coming decades. While human-mediated dispersal and climatic suitability have been crucial in shaping L. camara's current broad-scale distribution in South Africa, dispersal by birds and along rivers are important drivers of invasion at landscape scales. For example, current evidence suggests that in the Kruger National Park, L. camara has spread primarily along rivers. We conclude with a discussion on the implications of the different invasion dynamics for biological control and management, and provide recommendations for future research.
... We applied the treatments from August to October 2003. The initial clearing was performed in September 2003 according to Working for Water standards and consists of hand-pulling or spraying of seedlings and slashing of established plants followed by herbicide application to the remaining stumps (Van Gils et al. 2004; Euston-Brown et al. 2007). A follow-up clearing following the same procedure as the initial clearing Fire aids control of invasive shrub 609 and which is a standard practice in conventional clearing programmes, was performed in May 2005. ...
Successfully managing invasive plants in natural systems is extremely difficult. Recently however, progress has been made
with an approach focused on changing ecosystem processes through the disturbance regime. We performed a large-scale (3 ha)
full-factorial field experiment in densely invaded woodland in Hluhluwe-iMfolozi Park, a savanna reserve in South Africa,
to study the effect of fire on the control of the pan-tropical invasive exotic shrub Chromolaena odorata in combination with the conventional method, i.e. manual clearing and herbicide application. We show how fire interacted
with the conventional clearing of C. odorata and induced an intense canopy fire that caused a shift from woodland to grassland. After 2.5years of monitoring, grasses
were still dominant and re-invasion minimal. It is important to note that fire without prior clearing did not have the same
effect and was not successful in reducing densities of C. odorata. An integrated control practice targeting the species with mechanical and chemical methods, while simultaneously targeting
its habitat through fire, effectively controlled dense C. odorata thickets during the course of the experiment. However, this approach transformed regular surface fires into high-intensity
canopy fires that are rare in savannas. We discuss how this altered fire regime may threaten native habitats, including fire-sensitive
forest patches and riverine woodlands within the savanna mozaic. This is an important dilemma for managers that should not
be overlooked and asks for long-term data on the impact of control programs on the native vegetation.
KeywordsBiological invasions–Conservation–Fire–Hluhluwe-iMfolozi Park–Integrative management–Tree-grass dynamics
... To date, Wf W has spent approximately 180 million ZAR (7% of its total budget) on controlling L. camara invasions in South Africa (van Wilgen et al. 2012). However, the programme's success against L. camara invasions has been limited as cleared sites are often quickly reinvaded (Euston-Brown et al. 2007). ...
... Grassland and savanna ecosystem repair notes to accompany practical decision frameworks 1. Initial clearance (also see Euston-Brown et al., 2007) • For dense to closed woody alien stands, fell and remove large-diameter wood (N 50 mm) from the riparian zone. This wood may be sold to offset some of the clearance costs, or else stacked and left to decompose. ...
... In many practical restoration frameworks, the WfW norms, treatments and herbicide policies will be appropriate. Where habitat-specific tools have been developed, for example "Clearing Protocols for Mesic Savannas and Sweet Grassveld" (Euston-Brown et al., 2007), these should also be used to guide preliminary ecosystem repair. However, as these tools were developed primarily to maximise alien plant reduction, there are some instances where an ecosystem repair goal may require a deviation from these approaches. ...
This paper reviews the results of recent research on riparian vegetation recovery following the clearance of invasive alien plants. In Fynbos, Grassland and Savanna Biomes, riparian ecosystems were found to have relatively-high ecological resilience to invasion by alien plants, except in some situations of closed alien stands (75–100% aerial cover). Where alien invasion is the primary disturbance at a site, and invasion intensity is low (
... Grassland and savanna ecosystem repair notes to accompany practical decision frameworks 1. Initial clearance (also see Euston-Brown et al., 2007) • For dense to closed woody alien stands, fell and remove large-diameter wood (N 50 mm) from the riparian zone. This wood may be sold to offset some of the clearance costs, or else stacked and left to decompose. ...
... In many practical restoration frameworks, the WfW norms, treatments and herbicide policies will be appropriate. Where habitat-specific tools have been developed, for example "Clearing Protocols for Mesic Savannas and Sweet Grassveld" (Euston-Brown et al., 2007), these should also be used to guide preliminary ecosystem repair. However, as these tools were developed primarily to maximise alien plant reduction, there are some instances where an ecosystem repair goal may require a deviation from these approaches. ...
... Nevertheless, the invasion of C. odorata is a major global problem and seriously impacts many livelihoods in the tropics and subtropics. In 2007, an extensive management report came out giving thorough guidelines for the control of C. odorata in mesic savannas (Euston-Brown et al. 2007). I hope that my research can add to this and, therefore, I want to conclude with a set of management recommendations for the control of C. odorata in mesic savannas that have been derived from my research. ...
During the last century biological invasions have become an important global phenomenon and constitute one of the most serious threats to biodiversity worldwide. Invasions are characterized by the proliferation, spread and persistence of species in new areas that are often very distant from their native ranges. They largely result from the ever-expanding human transport and commerce that deliberately or accidentally distribute species around the face of the earth, moving them beyond their natural dispersal barriers. Invasive species can have profound impacts on the systems they invade, either directly, e.g. through predation or competitive exclusion of native species, or indirectly through altering fundamental ecosystem processes, like nutrient cycling, hydrology or fire regimes. The study of invasions is relevant not only from the perspective of conservation biology, but also provides important insights in the basic determinants of community structure, e.g. mechanisms relating to species coexistence and turn-over, niche theory or plant – soil interactions. The study of invasions has received more and more attention over the last decades and much work in invasion ecology has focused on identifying underlying mechanisms that explain invasion success. However, the basic questions ‘what determines a successful invader’ (species invasiveness) and ‘which communities are susceptible to invasion’ (community invasibility) remain yet largely unresolved and are the topic of ongoing research.
