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Yangzi cave, Guangxi, China. The cave entrance is approximately 70 m wide, 15 m high and the depth of the entrance cavern supporting vascular plants 170 m. This cave is type locality for 8 vascular plant species.
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Few studies document plants in caves. Our field observations of a widespread and seemingly angiosperm-rich cave flora in SW China lead us to test the following hypotheses, 1) SW China caves contain a diverse vascular plant flora, 2) that this is a relic of a largely absent forest type lacking endemic species, and 3) that the light environment plant...
Citations
... Along with microclimatic conditions, the trophic supply further contributes to characterizing subterranean habitats. The general lack of sunlight in caves prevents the survival of plants (with a few exceptions for more illuminated cave sections where some species, particularly Cryptogams plant, can be stable residents) [6]; the lack of primary producers drastically contributes to reducing the quantity of organic matter available to local communities [1]. Subterranean habitats are therefore strongly dependent on the external inputs of organic matter, which are more consistent near the cave entrance and almost absent in the deepest cave sections [7][8][9]. ...
Subterranean environments are often characterized by a natural gradient of microclimatic conditions and trophic resources, showing a higher trophic availability and a lower microclimatic stability in the shallowest area (close to the cave entrance), while the opposite occurs in the deepest sections. The shallowest areas of subterranean environments (e.g., the entrance and twilight zone, Mesovoid Shallow Substratum) act as ecotones between the surface habitats and the deep areas, creating a particular habitat which can be exploited by numerous species with different degrees of adaptation to subterranean environments. Species living in these ecotones may hold a key role in sustaining the entire ecosystem, as they are likely one of the major drivers of allochthonous organic matter. Indeed, these species are usually facultative cave-dwellers, meaning that they are able to exit and forage on the surface. Once these species are back inside the cave, they provide the local community with different typologies of organic matter (e.g., feces, eggs), which represent one of the most important sources of organic carbon. Therefore, studying which ecological features may exert significant effects on the abundance of these species may be of great help in understanding the ecosystem dynamics and the functional role of each species. In this study we analyzed the data collected through a year-round monitoring program, aiming to assess the potential effects that both abiotic and biotic features may have on the abundance of three facultative cave species. We focused on seven caves located in Monte Albo (Sardinia, Italy). The cave environments were divided into 3-meter sectors, and within each cave sector, microclimatic and biological data were seasonally recorded. We focused on the following facultative cave species: the spiders Metellina merianae and Tegenaria sp. and the snail Oxychilus oppressus. Different relationships were observed between the ecological features and the abundance of the three species. The two spiders were more abundant in warmer cave sectors closer to the cave entrance, especially the M. merianae. On the other hand, the snail tended to be more abundant farther from the cave entrance and in more illuminated cave sectors, probably because sunlight promotes the abundance of some of its trophic resources (e.g., lichens, vegetation). Furthermore, O. oppressus was the only species whose abundance and cave distribution was significantly affected by seasonality. This study provides useful and novel information to understand the population dynamics of facultative cave species and their role in subterranean ecosystems.
... However, the indirect impacts of these changes on the underground world can be "fatal" to the existing cave inhabitants (Trajano 2000). The causes of such changes can be diverse, and many human activities have implications for the subterranean realm (Ferreira and Horta 2001;Faille et al. 2015b;Monro et al. 2018;Costa Cardoso et al. 2021). In the actual context of a biodiversity crisis, the question of the conservation of these ecosystems and their inhabitants is a priority. ...
Planthoppers are an interesting and contrasting model among insects for studying the subterranean environments. Their morphological and ethological adaptations to the underground conditions (complete darkness, lower temperatures, high hygrometry, stability of environmental constants, rarefied food sources, etc.), and their worldwide distribution in both temperate and tropical areas make them an interesting model among invertebrates. In this review, we highlight why cave planthoppers study matters, with particular emphasis on the Cixiidae. The two hypotheses proposed, the ‘climatic relict hypothesis’ and the ‘adaptive shift’, are not sufficient enough to clearly understand and explain the drivers to cavernicoly. Phylogenetic analyses approaches might help to better document and increase our knowledge on such peculiar environments. The singularity of the distribution pattern of the adaptation to cavernicoly in planthoppers raises also interesting questions to investigate and suggest contrasting scenarios to explore further, particularly should the Cixiidae be defined as a subtroglophile lineage?
... In the late 20th century, Zhang et al. conducted detailed studies on bryophytes in karst caves in China [18,19]. Monro et al. discovered a high diversity of vascular plants in cave habitats in Southwest China and mentioned that the bryophytes in caves flourished, yet they did not identify bryophyte species [20]. Internationally, there have been relatively few reports on the diversity of bryophytes in lava caves, especially in China. ...
Volcanic lava cave habitats are extreme environments. We carried out field investigations for five years and reported the results of bryophyte diversity in eight volcanic lava caves of Jingpo Lake World Geopark, where the largest underground lava caves in China are preserved. The results are as follows: (1) A total of 230 quadrats were set up, and 2041 bryophyte specimens were collected. The specimens belong to 272 species of 107 genera in 47 families, including 26 liverworts (13 genera, 11 families) and 246 mosses (94 genera, 36 families). (2) The α diversity of bryophytes in Underground Lava Fall Cave was the highest, while that in Foggy Cave was the lowest. (3) The dominant families included Mniaceae, etc, accounting for 55.9% of the total species. The dominant genera included Plagiomnium, etc, accounting for 24.3% of the total species. The dominant species included Sanionia uncinata (Hedw.) Loeske etc. (4) There are no shared species among all eight lava caves, and each cave has a unique species composition. (5) Compared with that in other habitats in our previous studies, the similarity of bryophyte species between lava caves and underground forests of craters was high (113 species, 40.07%), while it was low between lava caves and lava platforms (9 species, 4.65%). Our study revealed that the lava caves have a high potential for bryophyte diversity, and such ancient ecological disaster sites are now rare refuges for bryophytes. Mosses are more adapted to cave habitats than liverworts. Bryophytes in this special eco-environment need to be considered and protected in order to preserve high-quality gene resources for humans, which is of great significance for the maintenance and development of biodiversity.
... These caves are viable ecosystems with a mix of invertebrate inhabitants that range from permanent cave dwellers to occasional visitors. Cave fauna was not investigated, however overseas studies have found that unique plant species can inhabitat cave entrances (Monro 2018) and play a part in cave ecosystems. ...
An extended version with additional cave notes, photographs and comments. Published in the NZSS Bulletin Vol.11 // No.222 // May 2023
... First, a profound understanding of cave climatology is essential for the successful protection of caves and their unique ecosystems as valuable natural resources. Several studies agree that caves contain some of the most vulnerable ecosystems on Earth (Noss & Peters, 1995;Elliott, 2000;Wynne & Pleytez, 2005;Wynne et al., 2007;Wood et al., 2008;Caraka et al., 2018;Reboleira et al., 2022), with numerous cave-dwelling organisms being endemic to a small region or even to a single cave (Barr & Holsinger, 1985;Reddell, 1994;Sarbu et al., 1996;Culver et al., 2000;Zhao et al., 2011;Monro et al., 2018;Nitzu et al., 2018). In times of rapid global climate and environmental change (Mannion, 2014;Rahmstorf & Schellnhuber, 2019;IPCC, 2021IPCC, , 2022, the relatively stable environmental and climatic conditions of caves increasingly make them refuge and archive for many endangered animal and plant species, which can no longer survive elsewhere (LaVal et al., 1977;Humphreys, 2000;Krajick, 2001;Christman et al., 2005;Judson, 2007). ...
... Of particular interest is the biota of the habitats of the cave entrance zones, which have several unique features. Unusual climatic conditions and high humidity (Northup and Lavoie 2001;Williams 2008), the presence of environmental gradients (Mulec et al. 2008), habitat diversity (Mulec et al. 2008;Novak et al. 2012;Czerwik-Marcinkowska 2013), the proven microrefugial role of the cave entrances as ecotones (Monro et al. 2018), determine the high biodiversity of phototrophs realized in small volumes of subterranean cavity entrances. The most popular are studies of species adaptations to cave environments, relationships and competition within populations and communities, features of reproductive strategies, the habitat-forming potential of cave biota, biodiversity formation, and the conservation value of cave photic zones (Serena and Meluzzi 1997;Pentecost and Zhaohui 2001;Tao et al. 2015;Monro et al. 2018;Puglisi et al. 2019). ...
... Unusual climatic conditions and high humidity (Northup and Lavoie 2001;Williams 2008), the presence of environmental gradients (Mulec et al. 2008), habitat diversity (Mulec et al. 2008;Novak et al. 2012;Czerwik-Marcinkowska 2013), the proven microrefugial role of the cave entrances as ecotones (Monro et al. 2018), determine the high biodiversity of phototrophs realized in small volumes of subterranean cavity entrances. The most popular are studies of species adaptations to cave environments, relationships and competition within populations and communities, features of reproductive strategies, the habitat-forming potential of cave biota, biodiversity formation, and the conservation value of cave photic zones (Serena and Meluzzi 1997;Pentecost and Zhaohui 2001;Tao et al. 2015;Monro et al. 2018;Puglisi et al. 2019). ...
... It can be assumed that large cave entrances, as in Kutuk-Sumgan Cave, have more diverse habitats, which affects biodiversity. This fact can be confirmed by the studies of Monro et al. (2018) and Ren et al. (2021) in caves in China. ...
This article presents results of a study of bryophytes in seven caves of the Kutuk tract of the National Park «Bashkiria» of the Republic of Bashkortostan, including the largest cave in Bashkiria – Kutuk-Sumgan.Fifty-five bryophytes species were found in the studied caves. The dominant species in all caves was Timmia bavarica. The species composition of bryophytes of each cave is unique. Among identified bryophytes species 23, species were found only in one cave, and 11 species in 2 caves. During our survey, we found 31 species in Kutuk-Sumgan Cave, 21 species in Kutuk-2 and Kutuk-3 caves, 19 species in Kutuk-4 caves, 18 species in Vintovaya and Zigzag caves and 14 species in Kutuk-1 cave. Using the Jaccard and Phi-squared similarity indices, we revealed the stability of the bryoflora of the caves in different years and show its changes. Changes in the composition and structure of mosses in the Kutuk tract may be caused by mechanical influences. Benchmark similarity analysis allowed us to determine the influence of entrance morphology and glaciation in the photic zone of the caves on the composition of bryophytes.Using the Kutuk tract caves as an example, it is shown that in the primary analysis of the bryoflora, when selecting a characteristic cave, up to 40% of the total species composition of the caves can be identified in a single cave. The current study of Kutuk tract caves shows that identification of the primere analyses of bioflora permits identification of up to 40% of species composition of an individual cave.Three criteria for selecting a characteristic cave were identified: size of the photic zone and morphology of the entrance, diversity of habitats, and the least degree of disturbance.
... In this case, changes in the species composition can only be associated with stress factors. Cave studies conducted in southwestern China confirmed the microrefugia role of cave entrance zones, and the flora of the photic zones was determined to be a relic of the regional karst forest flora [48]. The identified algoflora in the caves of Gobustan can be interpreted as lithophilic communities, characteristic of caves, as species enduring seasonal adversity in the caves, and even relict species. ...
Unique natural objects, such as the caves of the Gobustan National Historical and Artistic Preserve, are also of great cultural and historical value due to rock art and sites of ancient people. A favorable microclimate makes these habitats convenient for colonization by microbiota, including phototrophs. In arid regions with intense seasonal fluctuations of microclimatic parameters, the conditions for survival are the least favorable; therefore, it becomes especially important to determine the composition of communities that are the most adapted to specific conditions. This work aimed to identify the biodiversity of communities of caves and grottoes of the Gobustan Reserve. The studies were carried out in July 2019. Samples were analyzed for cyanobacteria and algae by microscopy and cultivation methods, microfungi were isolated by soil dilution, and the fouling glass method was also used. In total, 29 taxa of cyanobacteria and algae, 18 taxa of fungi, and 3 species of mosses were identified. The studied habitats were dominated by the algae Chlorella vulgaris, Aphanocapsa sp., and Stichococcus bacillaris; the subdominants were Jaaginema subtilissimum, Leptolyngbya tenuis, Chlorococcum minutum, and Humidophila contenta. Microfungi had the highest occurrence of Aspergillus niger, Aureobasidium pullulans, Alternaria alternata, and Talaromyces ruber. It was noted that cyanobacteria dominated in morphologically differentiated biofilms and green algae on the rocks. The greatest number of microfungi was found in the aphotic zone and bryophyte tufts. The dominance of green algae is atypical for most caves of other regions and may be associated with intense lighting of habitats. The absence of protonema is a consequence of the aridity and low moisture content of the substrates.
... & G. Forst. is a large genus of Urticaceae containing several hundred species distributed throughout tropical and subtropical Asia (Christenhusz et al. 2017;Fu et al. 2021). Elatostema is a succulent herb normally found in evergreen forest, along stream, gorges, caves and limestone mountains (Wang 2014;Fu et al. 2017;Monro et al. 2018). Based on molecular and morphological evidences, a recent systematic study (Tseng et al. 2019) demonstrated that Elatostema is a monophyletic genus that includes Pellionia Gaudich. ...
Three new species of Elatostema (Urticaceae) from Thailand, E. kaweesakii Triyutth. & L.F.Fu, sp. nov. , E. rubricaule Triyutth. & L.F.Fu, sp. nov. and E. saxatile Triyutth. & L.F.Fu, sp. nov. , are newly described and illustrated. These new species can be distinguished by the presence of rhizome. Elatostema kaweesakii is similar to E. atroviride . Elatostema kaweesakii is a lithophyte growing in limestone crevices. It differs from E. atroviride by its large swollen rhizome, glabrous stem, glabrous receptacle, number of tepal in staminate flower, absence of tepal in pistillate flower, presence of staminodes in pistillate flower and smooth achene. Elatostema rubricaule and E. saxatile are found on sandstone habitats. They have distinct flattened and disk-like rhizome. Elatostema rubricaule is distinguished by its distinct sulcate and reddish stem with flattened and disc-like rhizome and chartaceous leaves with entire margin. Elatostema saxatile resembles E. bulbiferum but differs by its flattened and disc-like rhizome, acute leaf apex, glabrous receptacle in pistillate inflorescences, presence of staminodes in pistillate flower, and its sandstone habitat. Descriptions, distribution, ecological and phenological data are provided.
... They use Rheum leaves as vegetables and they dry the roots of Rheum plants for different purposes, e.g. wounds, boils, scars and digestion problems [1,15,36]. ...
... Although the karst region is a World Heritage Site, the level of anthropogenic disturbance has reached unprecedented proportions. Anthropogenic activities in this region include quarrying, mining, soil erosion, sewage discharge, construction of roads, tourism activities, and hydroelectric projects (Zhao and Zhang, 2009;Lan et al., 2013;Li et al., 2016;Monro et al., 2018;Niemiller and Taylor, 2019;He et al., 2021). ...
Subterranean aquatic biodiversity loss has exceeded that of surface aquatic systems, and cavefish are a predominant indicator of biodiversity loss. The karst subsurface environment and its biodiversity are generally considered to be fragile and extremely sensitive to environmental disturbances such as hydroelectric projects. Subterranean biodiversity is faced with several threats, such as: hydrostation mining, domestic wastewater etc., and protecting and managing these unique and endemic species presents several challenges of wild population survive and monitoring population dynamic. The impact of infrastructure policies on cavefish species in China is used as an example to analyse the current and potential threats to cavefish species and karst subterranean habitats in China. Any strategy employed to conserve cavefish in China should include strengthening research on cavefish, including formal descriptions of taxa and listing these species on the IUCN Red List, as well as national and local lists of species for conservation. Such knowledge can be used to establish a conservation strategy for cavefish and subsurface biodiversity.
