Karst Habitats Research Articles

A re-evaluation of the phylogenetic relationships of the Cyrtodactylus condorensis group (Squamata; Gekkonidae) and a suggested protocol for the characterization of rock-dwelling ecomorphology in Cyrtodactylus

A re-evaluation of the phylogenetic relationships of the four species of the monophyletic Cyrtodactylus conodorensis group using the mitochondrial gene ND2 with Bayesian and Maximum Likelihood analyses provides strong statistical support for the recovery the cave-adapted ecomorphs C. eisenmanae and C. grismeri as the sister lineage to the scansorial forest-adapted ecomorphs C. condorensis and C. leegrismeri. This phylogeny provides the context in which these ecomorphs are morphologically characterized. The majority of newly described species within Cyrtodactylus have come from karst habitats and granite boulder cave-like microhabitats. Although some authors have commented on subtle to notable differences in the morphology and color pattern associated with species from these habitats, none have explicitly presented data necessary to characterize this putative departure from a more generalized, scansorial morphology. To this end, the closely related species of the condorensis group are used to provide a suggested protocol to recover and delimit characters adaptive to a restrictive lifestyle of climbing on flat, rocky substrates in low levels of illumination. Understanding the phylogenetic context in which a morphological shift from a general scansorial species to a rock-adapted species relative to the historical evolution of its environment has conservation and management implications. This is particularly important given that a number of the newly described karst-adapted species from throughout Southeast Asia are threatened with extension because of the ongoing quarrying activities of their habitat.

Differences between caves with and without bats in a Brazilian karst habitat

ABSTRACT. Since bats shelter in roosts during their period of diurnal inactivity, the quality and availability of roosts are important aspects of their ecology. Karst areas have great potential for the availability of day roosts, since they form caves, which serve as bat shelters. Here we characterize the caves used by bats in a preserved karst area of Southeastern Brazil. Using logistic regression analysis we identified the cave characteristics that influence bat occupation. Sixty-six caves were characterized based on measurements of internal height and width, height and width of the entrance(s) of the cave, number of entrances, maximum horizontal development of cave, and internal temperature and humidity. In nineteen months we found 14 species in 32 caves. Most species were eventually recorded in multiple caves, with the exception of D. rotundus, G. soricina and A. planirostris, which were always found in the same caves. Desmodus rotundus showed maternity roost fidelity. We found no differences in microclimate between the caves that are occupied and those that are not. In other words, the microclimate of the caves studied herein can be characterized as stable over the years. The only predictor affecting the presence of bats in the study area was the cave’s maximum horizontal development: the caves that are occupied have greater horizontal development. Based on our results, we conclude that bats occupy many of the caves and that some species are more frequent in certain caves than in others, including some roosts that are used as maternity roosts. These findings indicate that these caves are important resources for the bats in the karst environment studied, and should be preserved.

Ecological traits of dragonfly (Odonata) assemblages along an oligotrophic Dinaric karst hydrosystem

Ecological traits of dragonfly larvae in tufa-depositing habitats of the Dinaric karst were studied monthly over a one-year period (2007–2008). The study encompassed various lotic karst habitats (springs, mountainous rivers, streams, tufa barriers) and microhabitats (angiosperms, mosses, cobbles, sand, silt with leaf litter). The aims of the study were to identify dragonfly composition, abundance and spatial distribution, their habitat and microhabitat preferences, and to determine the most important environmental factors explaining dragonfly assemblages in the studied hydrosystem. The dragonfly fauna was composed of eight species, Onychogomphus forcipatus (Linnaeus, 1758) was the most widespread and the most numerous. Water temperature, ammonium and oxygen concentrations had the highest influence on dragonfly assemblages. The most favorable habitat type were tufa barriers, less favorable were lower lotic habitats, while dragonflies were almost completely absent from upper lotic habitats and their springs. Dragonfly larvae preferred microhabitats with inorganic substrates (i.e. cobbles and sand) and slower water velocity, while they mostly avoided mosses associated with the strongest current. This study provides an important contribution to the knowledge of dragonfly ecology in lotic habitats of the Dinaric karst.

Development of microsatellite markers in Garcinia paucinervis (Clusiaceae), an endangered species of karst habitats.

Premise of the study:Microsatellite markers were developed for Garcinia paucinervis (Clusiaceae), an endangered and endemic tree species of karst habitats, to analyze its genetic diversity and genetic structure.Methods and Results:Using shotgun sequencing on an Illumina MiSeq platform, a total of 22 microsatellite primer sets were characterized, of which 17 were identified as polymorphic. For these polymorphic loci, the total number of alleles per locus ranged from two to 12 across 54 individuals from three populations. The observed and expected heterozygosities ranged from 0.000 to 1.000 and from 0.000 to 0.850, respectively. No pair of loci showed significant linkage disequilibrium. Three loci in one population deviated significantly from Hardy–Weinberg equilibrium (P < 0.05). Seven loci (JSL3, JSL5, JSL22, JSL29, JSL32, JSL39, and JSL43) were successfully amplified in G. bracteata.Conclusions:These markers will be useful in studies on genetic diversity and population structure of G. paucinervis.

The Relationship between pH and Bacterial Communities in a Single Karst Ecosystem and Its Implication for Soil Acidification.

Enhanced monsoon duration and soil acidification from acid rain are expected to impact the distribution of microbial communities in surface and subsurface environments, although these impacts are poorly understood for most systems. In central China, soluble carbonate bedrock forms extensive karst landscapes. Current predictions are that the amount of monsoonal precipitation and acid rainfall in central China will increase, which is expected to lead to changes in the pH balance of karst ecosystems. To evaluate the role of pH, total organic carbon, and other geochemical parameters (e.g., Ca2+, Mg2+, NH4+, NOx, SO42-) in shaping bacterial communities within a single karst system in central China, samples were collected from the thin surface soils overlying Heshang Cave, cave sediments, and weathered cave passage rocks from the entrance, twilight, and dark zones, as well as from epikarstic drip waters inside the cave. Illumina sequencing of 16S rRNA genes and multivariate statistical analyses revealed that each tested community was distinct and the community variability was significantly correlated with pH, total organic carbon, and potassium concentrations. Specifically, surface soils were dominated by Acidobacteria, Verrucomicrobia and Planctomycetes, and diversity significantly decreased with acidic pH values. Nitrospirae, Gemmatimonadetes, Firmicutes, and Chloroflexi were unique to cave sediments, while Actinobacteria and Proteobacteria dominated weathered rocks and drip waters, respectively. The results reveal important implications regarding the effects of acidification on bacterial communities in karst areas, and on the control of pH in shaping bacterial communities throughout a karst system. Increased water flux into and through karst habitats due to monsoonal precipitation may result in deeper penetration of acidic solutions into karst and shift the bacterial communities inside the cave in the future.

Distribution and life-history traits of Calathus cinctus Motschulsky, 1850 (Coleoptera: Carabidae) in Croatia, with distribution of closely related species

Calathus cinctus Motschulsky, 1850 was only recently separated from the group Calathus melanocephalus (Linnaeus, 1758). C. cinctus has now been recorded for the first time in Croatia, along the temporary Krčić River situated beneath Mt. Dinara. However, revision of museum collections revealed that this species also occurs at other localities in Croatia, in the Alpine region and along the Adriatic coast. Its sister species C. melanocephalus, as the type species of the group, is widely distributed in Croatia, whereas C. mollis Marsham, 1802 is mostly restricted to the coastal region, with a few records from Alpine and Continental Croatia. The distribution range of C. cinctus overlaps with the distribution ranges of its sister species. Life-history traits were studied using pitfall traps in a karst region of Croatia, including eu-Mediterranean and sub-Mediterranean zones, in riparian and karst habitats, and on agricultural land. Based on goodness-of-fit criteria, the zero-inflated negative binomial model and negative binomial model best described the distribution of C. cinctus. For both models, there was a statistically significant difference between habitat types for activity density, indicating that C. cinctus has a preference for open habitats. It was recorded above a range of soil types (e.g. red, brown, sandy, cultivated), with sparse vegetation, suggesting that sufficient sun exposure is a more important requirement than soil type. The seasonal dynamics of C. cinctus differed between eu-Mediterranean and sub-Mediterranean zones, despite the rather close proximity of the studied localities. Geographical variability of seasonal activity was most likely due to differences in climate, altitude and the vicinity of the high mountain. Calathus cinctus populations in both zones were wing-dimorphic, with brachypterous specimens prevailing in both populations, indicating population stability.

Geographical pattern of isolation and diversification in karst habitat islands: a case study in the Primulina eburnea complex

AbstractAimThis study aimed to clarify species boundaries as well as phylogenetic relationships among species of the Primulina eburnea complex, a rapidly diversifying group of edaphic specialists confined to karst habitat islands in southern China. We investigated patterns of genetic isolation and diversification in this complex.LocationLimestone karsts in southern China.MethodsWe analysed data from three chloroplast DNA (cpDNA) regions and eight nuclear microsatellite loci, representing five closely related species in the P. eburnea complex sampled from 62 populations across its entire distributional range. We conducted a Bayesian phylogenetic analysis, constructed maximum parsimony haplotype networks and assessed population genetic diversity, population differentiation and geographical structure within and between species.ResultsOf the 60 identified haplotypes, eight were shared between populations and only one was shared between species. Both cpDNA and the nuclear markers revealed a high level of population genetic differentiation and a strong phylogeographical structure. Four main genetic clusters were identified according to their geographical proximity, although geographical structuring differed slightly between the cpDNA and the nuclear loci. The pattern of genetic structure of both the cpDNA and microsatellite genomes can be explained by patterns of isolation by distance (IBD), across both the distribution of the complex and the populations of individual species.Main conclusionsThis is the first study to investigate geographical isolation and speciation in a clade associated with karst habitat islands in southern China. Geographically structured population differentiation of the P. eburnea complex suggests that divergence is mainly driven by genetic drift, with little evidence of gene flow. Allopatric speciation is the main mode of diversification in the group. These results highlight the importance of geographical isolation in promoting population differentiation in karst habitat islands.

Vegetation in karst terrain of southwestern China allocates more biomass to roots

Abstract. In mountainous areas of southwestern China, especially Guizhou province, continuous, broadly distributed karst landscapes with harsh and fragile habitats often lead to land degradation. Research indicates that vegetation located in karst terrains has low aboveground biomass and land degradation that reduces vegetation biomass, but belowground biomass measurements are rarely reported. Using the soil pit method, we investigated the root biomass of karst vegetation in five land cover types: grassland, grass–scrub tussock, thorn–scrub shrubland, scrub–tree forest, and mixed evergreen and deciduous forest in Maolan, southern Guizhou province, growing in two different soil-rich and rock-dominated habitats. The results show that roots in karst vegetation, especially the coarse roots, and roots in rocky habitats are mostly distributed in the topsoil layers (89 % on the surface up to 20 cm depth). The total root biomass in all habitats of all vegetation degradation periods is 18.77 Mg ha−1, in which roots in rocky habitat have higher biomass than in earthy habitat, and coarse root biomass is larger than medium and fine root biomass. The root biomass of mixed evergreen and deciduous forest in karst habitat (35.83 Mg ha−1) is not greater than that of most typical, non-karst evergreen broad-leaved forests in subtropical regions of China, but the ratio of root to aboveground biomass in karst forest (0.37) is significantly greater than the mean ratio (0.26 ± 0.07) of subtropical evergreen forests. Vegetation restoration in degraded karst terrain will significantly increase the belowground carbon stock, forming a potential regional carbon sink.

A new species of nocturnal gecko (Paroedura) from karstic limestone in northern Madagascar

Paroedura hordiesi sp. n. is described from Montagne des Français, a karstic limestone massif in the far north of Madagascar recently established as nature reserve. The new species has the nostril in contact with the rostral scale and shares many characters with P. karstophila and especially with P. homalorhina which are also restricted to karstic habitats. Paroedura hordiesi differs from P. karstophila by a smoother skin on dorsum and legs, by original and regenerated tails being both entirely smooth, by colouration, and by larger snout-vent length. Morphologically the new species is most similar to P. homalorhina from the Ankarana reserve from which it can be distinguished by shorter limbs and a less slender habitus. Published molecular data place the new species as close relative of P. homalorhina and another undescribed species from Nosy Hara Island, while newly determined data of the cox1 gene for P. karstophila confirm the distinctness of the new species from this taxon. Integrating the information from published and novel molecular data, the new species differs from all nominal Paroedura (except P. vahiny for which no molecular data are available to date) by strong genetic divergences. P. hordiesi might be another microendemic species of the Montagne des Français region. We suggest its IUCN Red List classification as “Critically Endangered” on the basis that it has an extent of occurrence of at most 50 km², it is known from a single location, and there is a continuing decline in the extent and quality of its habitat.

Dietary adaptations of Assamese macaques (Macaca assamensis) in limestone forests in Southwest China.

Limestone hills are an unusual habitat for primates, prompting them to evolve specific behavioral adaptations to the component karst habitat. From September 2012 to August 2013, we collected data on the diet of one group of Assamese macaques living in limestone forests at Nonggang National Nature Reserve, Guangxi Province, China, using instantaneous scan sampling. Assamese macaques were primarily folivorous, young leaves accounting for 75.5% and mature leaves an additional 1.8% of their diet. In contrast, fruit accounted for only 20.1%. The young leaves of Bonia saxatilis, a shrubby, karst-endemic bamboo that is superabundant in limestone hills, comprised the bulk of the average monthly diet. Moreover, macaques consumed significantly more bamboo leaves during the season when the availability of fruit declined, suggesting that bamboo leaves are an important fallback food for Assamese macaques in limestone forests. In addition, diet composition varied seasonally. The monkeys consumed significantly more fruit and fewer young leaves in the fruit-rich season than in the fruit-lean season. Fruit consumption was positively correlated with fruit availability, indicating that fruit is a preferred food for Assamese macaques. Of seventy-eight food species, only nine contributed >0.5% of the annual diet, and together these nine foods accounted for 90.7% of the annual diet. Our results suggest that bamboo consumption represents a key factor in the Assamese macaque's dietary adaptation to limestone habitat.

First Record of the Gekkonid Genus Cnemaspis Strauch, 1887 from Gunung Mulu National Park, Northern Sarawak, East Malaysia may Represent an Undescribed Species

We provide confirmed photographic evidence for the previously overlooked occurrence of the polyphyletic Asian gecko genus Cnemaspis from Gunung Mulu National Park, the world-renowned UNESCO natural heritage site in northern Sarawak, East Malaysia. This new record from Sarawak province represents a remarkable range extension for Cnemaspis cf. kendallii by 550 km to the northeast and denotes the most northern occurrence of the genus in Borneo. Our new finding makes it very likely that these gekkonid lizards also inhabit appropriate limestone karst habitats in adjacent Sabah, Brunei, and Kalimantan. Given the visible differences in the Mulu specimen compared to those from the remaining distribution range on Borneo and the Malaysian Peninsula together with the fact that numerous Cnemaspis species are restricted to small areas, it seems plausible that another undescribed, rather cryptic and possibly locally endemic Bornean species is involved. Lastly, the new record contributes to the importance of the Mulu National Park as a major conservation area in East Malaysia of international concerns.

Seasonal variations in leaf δ13C values: implications for different water-use strategies among species growing on continuous dolomite outcrops in subtropical China

Plant species growing in shallow-soil habitat are likely to experience water deficit especially in seasonally dry or arid regions. However, only scarce studies focused on their water-use strategies. The current study aimed to reveal water-use strategies of different species growing on continuous dolomite outcrops (a typical shallow-soil habitat) in subtropical China that relied on different water sources, and to investigate the differences between narrow endemic and widespread species, based on season variations in leaf δ13C values. Leaf samples of six plant species (Radermachera sinica, Sapium rotundifolium, Sterculia euosma, Schefflera octophylla, Alchornea trewioides, and Vitex negundo, in different life-forms and leaf phenologies) were collected for carbon isotope measurements in the wet and dry seasons, respectively. Contrary to the expectation, the evergreen big shrub species, S. octophylla, which always relied on deep water sources, exhibited the most positive δ13C values (high water-use efficiency, WUE), indicating more conservative water-use strategies. While the two deciduous small shrubs, A. trewioides and V. negundo, which always relied on shallow water sources, exhibited the most negative δ13C values (low WUE). This result was associated with their short life spans, indicating an opportunistic water-use strategy. Leaf δ13C values of almost all (except for S. octophylla) the selected species were significantly (P < 0.05) higher in the dry season than in the wet season. This indicated that it was a common strategy for species in rocky karst habitat to improve their WUE in dry season. Despite the similar water sources utilized by the selected three tree species, the widespread one (R. sinica) exhibited greater improvement in leaf δ13C values than the narrow endemic ones (S. rotundifolium and S. euosma). This suggested that the widespread tree species had more flexible water-use strategies. It was further speculated that broad spatial distribution of widespread species may contribute to their highly plastic responses to changes in environmental conditions rather than always maintaining high WUE.

Rooting characteristics of two widely distributed woody plant species growing in different karst habitats of southwest China

A series of studies claimed that deep root development of plant established in karst regions was facilitated by fractured bedrock beneath the shallow soils; however, bedrock is not a uniform medium for root proliferation. We hypothesized plant species that survived in different karst habitats had some other rooting characteristics rather than deep penetration. To test the hypothesis, coarse root systems of two widely distributed woody species (one tree and one shrub) growing in three typical rocky karst habitats (shallow soil, loose rocky soil and exposed rock) were excavated in karst region of southwest China. Root systems were investigated based on four parameters: maximum rooting depth, maximum radial extent, root tapering pattern and root curvature. In all the three habitats, maximum rooting depths were no deeper than 120 and 40 cm for the tree and shrub species, respectively. Maximum radial extents were extremely large compared with maximum rooting depth, indicating that rooting characteristics were dominated by horizontal extension rather than deep penetration. Roots of both species growing in shallow soil habitat tapered gradually and curved slightly, which was consistent with the specific characteristics of this habitat. On the contrary, roots of the tree species growing in the other two habitats tapered rapidly but curved slightly, while roots of the shrub species tapered gradually but curved strongly. It was speculated that limited depths and rapid tapering rates of the tree roots were likely compensated by their utmost radial extensions, while the shrub species might benefit from its root curvature as the associated root tropisms may increase the ability of root to encounter more water and contribute to potentially high resource absorption efficiency. Our results highlight the importance of taking shallow-rooted species into account in understanding the distribution of natural plant communities and predicting future vegetation dynamics in karst regions.

Assessing the status of a disjunct population of the endangered crayfish Euastacus bispinosus in a karst rising‐spring habitat in southern Australia

Abstract Many species of freshwater crayfish of the endemic Australian genus Euastacus are threatened with extinction. Routine monitoring of most Euastacus species is minimal, and a subsequent lack of information has hampered prioritization of conservation and management efforts. The present study investigated population parameters and temporal changes in abundance in a disjunct population of Euastacus bispinosus. This occurs at the western extent of the range of the species in the state of South Australia (SA) and inhabits a groundwater‐dependent karst habitat distinct from the larger population in the Victorian Glenelg basin. Euastacus bispinosus was recorded at sites within seven karst rising‐springs as well as two isolated locations (sinkhole and cave), which expanded the extent of occurrence of the species in SA, but the area of occupancy remains limited. Most subpopulations contained low numbers, had little or no signs of recruitment, were dominated by large crayfish, and demonstrated a high incidence of gonopore aberrations. Declines in abundance were observed across these subpopulations between 2006 and 2011, although these declines were not statistically significant. Of critical importance to the conservation of the species in SA is ensuring that groundwater discharge is maintained in karst rising‐springs, hydrological connectivity is enhanced between subpopulations and degradation within habitats is reversed. Further monitoring and research is necessary to gain a clear understanding of the status of subpopulations of the species over time. Copyright © 2014 John Wiley &amp; Sons, Ltd.

Implications of the Ecophysiological Adaptation of Plants on Tropical Karst Habitats for the Ecological Restoration of Desertified Rocky Lands in Southern China

Karst lands are widely spread in China, particularly in Southwest China, which cover the largest continuous karst area with a unique landscape. Due to the human interference for a long time and the special substrate and hot and humid climate, the karst lands in this region have been severely degraded, the desertified rocky karst lands now totally cover the area of 1.2×105 km2 in southern China. This results in environmental deterioration and difficulty for the social and economical development. Karst lands in southern China are characterized with thin or little soil, low soil nutrients and low water holding capacity. We have done a series of research on the ecophysiological adaption of plants on a tropical karst mountain. In this article, we briefly synthesize our research and the key findings, and also some other research in order to provide reference information for the ecological restoration of desertified karst lands. Our studies have indicated that the co-existence of evergreen and deciduous trees and lianas is helpful for the maintenance of water balance of karst ecosystems. The evergreen trees are tolerant to water deficit and xylem cavitation, while deciduous trees shed leaves to reduce water use in the dry season. Most of karst woody plants have deep roots, while the lianas have the deepest roots in order to reach deeper water source belowground in dry season. Some plants such as Bombax ceiba Linn. and Caryota urens Linn. store water in their stems to support the necessary physiological processes in dry season. Most of the tropical karst plants are short of Zn and K nutrients according to the foliar nutrient analysis, this should be taken into account during the ecological restoration and agricultural practices. Lianas are able to use the localized water and nutrients and employ the abundant light source and spaces of desertified karst lands by means of their climbing stems. They often have high photosynthesis and strong regulation of water use, and are useful plant materials for the restoration of the desertified karst lands. An important oil liana, Plukenetia volubilis L, is now recommended for plantation by the Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, which is an ideal plant for the restoration of desertified karst lands. The ecological restoration of desertified karst lands could consider using different function groups of plants to construct a multiple-storey community.

Eco-physiological adaptation of dominant tree species at two contrasting karst habitats in southwestern China

The purpose of this study was to investigate the eco-physiological adaptation of indigenous woody species to their habitats in karst areas of southwestern China. Two contrasting forest habitats were studied: a degraded habitat in Daxiagu and a well-developed habitat in Tianlongshan, and the eco-physiological characteristics of the trees were measured for three growth seasons. Photosynthetic rate (Pn), stomatal conductance (gs), and transpiration rate (Tr) of the tree species in Daxiagu were 2-3 times higher than those in Tianlongshan under ambient conditions. However, this habitat effect was not significant when measurements were taken under controlled conditions. Under controlled conditions, Pn, gs, and Tr of the deciduous species were markedly higher than those for the evergreen species. Habitat had no significant effect on water use efficiency (WUE) or photochemical characteristics of PSII. The stomatal sensitivity of woody species in the degraded habitat was much higher than that in the well-developed habitat. Similarly, the leaf total nitrogen (N) and phosphorus (P) contents expressed on the basis of either dry mass or leaf area were also much higher in Daxiagu than they were in Tianlongshan. The mass-based leaf total N content of deciduous species was much higher than that of evergreen species, while leaf area-based total N and P contents of evergreens were significantly higher than those of deciduous species. The photosynthetic nitrogen- and phosphorus-use efficiencies (PNUE and PPUE) of deciduous species were much higher than those of evergreens. Further, the PPUE of the woody species in Tianlongshan was much higher than that of the woody species in Daxiagu. The results from three growth seasons imply that the tree species were able to adapt well to their growth habitats. Furthermore, it seems that so-called "temporary drought stress" may not occur, or may not be severe for most woody plants in karst areas of southwestern China.

Aquatic biota of different karst habitats in epigean and subterranean systems of Central Brazil – visibility versus relevance of taxa

The karstic area of S&atilde;o Domingos, central Brazil, holds extensive drainage systems. In order to understand its biodiversity, various volumes of water were filtered with planktonic nets in stretches of subterranean and superficial rivers on five different occasions. We sampled four drips (152L), three calcite pools (368L), two subterranean rivers fed mainly by percolation water (6,395L), two subterranean rivers fed mainly by water coming from a sinkhole (4,175L) along different caves, one resurgence (158L), and four epigean rivers (101,690L). Physical and chemical variables were measured at some sites. Canonical Correlation Analysis was used to verify relationships between taxa and environment. The degree of similarity of the biota was assessed by cluster analysis (Sorensen, single linkage). There were records of exclusive taxa in epigean and subterranean samples, mainly in drips, which harbour the most unique fauna. The high richness of taxa presently recorded reveals the potential of the vadose zone biota in the tropical region, which was neglected in studies on Brazilian subterranean biodiversity. According to our results, the unsaturated zone tropical fauna may have different composition compared to that from temperate habitats. The studied communities were dominated by rotifers, while crustacean are predominant in the latter. The hypothesis can be clarified with the increase of long term studies and taxa identification at species level, besides the use of complementary sampling methods.

A new species of Kaloula (Amphibia: Anura: Microhylidae) from southern Guangxi, China.

A new species of narrow-mouthed frog of Kaloula is described in the Nonggang National Nature Reserve, Sino-Vietnamese border region of southern China. Kaloula nonggangensis sp. nov. is distinguished from its congeners by a combination of the following characters: medium size (SVL 41.4-52.7 mm in 18 adult males, 52.2 mm in 1 female); smooth or slightly rough olive dorsum with irregular dark-green marks and brown spots; tips of the fingers widely dilated and truncated; males with nearly fully webbed toes; males with two side protuberant osseous tubercles on the upper surface of the tips of fingers and chest beige with small lemon-colored spots. K. nonggangensis sp. nov. is found in habitats ranging from cultivated fields adjacent to the forest to primary evergreen forest in karst habitats. Based upon a 16S ribosomal RNA mitochondrial gene fragment, K. nonggangensis sp. nov. is embedded within the K. verrucosa group (including K borealis, K. rugifera and K. verrucosa), and displays a low genetic distance to these species (< 3%). Considering the distinct morphology and karyotype we nevertheless suggest a status as separate species for these allopatrically distributed lineages.

Stable Isotopic Study on Water Utilization Sources of &lt;i&gt;Pinus yunnanensis &lt;/i&gt;Plantations in the Central Yunnan Karst Plateau

In order to explain the water utilization mechanism of Pinus Yunnanensis plantations in the Central Yunnan Karst Plateau, SW China, and their adaptive strategies to arid karst habitat, the authors collected and analyzed the stable 18O isotope values of stem water of Pinus Yunnanensis in Bajiang valley, and their accompanying trees and bushes and their potential water sources. The IsoSource model was applied to compute the probable contribution of multiple potential water sources to total plant. The results show that in the ecosystem of Pinus Yunnanensis plantations, there exists significant evaporative isotopic fractionation during the process of hydraulic infiltration from precipitation to ground water and soil water and that of hydraulic redistribution in the soil profile. Water utilization positions and proportions of Pinus Yunnanensis and its accompanying trees and bushes vary from season to season, and they are evident competitors for water. During dry seasons, mature Pinus Yunnanensis uses 68.6% of 0-55cm soil water while the contribution of 30-110cm soil water and groundwater to the young Pinus Yunnanensis reaches 55.8% and 31.7% respectively. In rainy seasons, the use ratio of 0-55cm surface soil water by young Pinus Yunnanensis, Pistacia weinmannifolia and Rhododendron spiciferum are 63.1%, 56.3% and 86.2% respectively while the mature Pinus Yunnanensis uses rainfall, groundwater and fog droplets of canopy interception.

Process of biodiversity research of Karst areas in China

Because the Karst environment is very sensitive to disturbance, once a strong disturbance occurs in a Karst ecosystem it will undergo reverse succession, and both its recovery and restoration might be difficult. So, biodiversity is an important factor in maintaining existing Karst landscapes and also provides the basis for recovery of degraded Karst ecosystems. Karst restoration has become the core issue in research related to environmental changes in Karst areas. With the implementation of the World Heritage List and Rocky Desertification Project in recent years, the number of related research papers has shown rapid growth and Karst has become one of the important topics of new research. This paper uses the CNKI (China National Knowledge Infrastructure) and Springer databases as well as the Taylor & Francis UK database as data sources; the result shows: (1) the quantity of Karst related journal articles is on the rise, exceeding 20 articles per year since 2008; (2) Karst related journal articles focus on two major categories, ecology (51) and environmental engineering (41); (3) the literature mainly comprises jointly produced documents, and most are from the core research team of Wang Kelin, Su Weici, Xiong Kangning. Based on statistical results, we comprehensively review two theses and 89 academic papers and use combined data from the internet and correlation analysis to give a scientific overview of recent literature. The result can be seen in three ways. First, 39 papers have been published on mechanisms that maintain biodiversity>20 papers on the characteristics of diversity>20 papers on monitoring and evaluation of diversity>13 papers on Karst restoration and reconstruction of diversity. Second, the research concentrated on three aspects, namely, 16 papers on the characteristics of native biodiversity, 17 on biological mechanisms that maintain biodiversity, and 15 on non-biological mechanisms for maintaining biodiversity. Third, for comparing natural Karst habitats with degraded habitat in two contrasting ecological landscapes, the paper elaborates on dynamic biodiversity research in Karst areas from different perspectives and different fields and scientifically analyses the correlations of literature from these different perspectives. This paper is based on a brief summary of research related to biodiversity in Karst regions, as well as research related to the perspectives of specific geological and geomorphological conditions of Karst regions and clarifies the basic condition of biological diversity in Karst areas. Four problem areas are identified that need to be the subject of future studies. First, research related to genetics, species and ecosystem research needs to be integrated and strengthened and further study of mechanisms related to genetic variation, species in Karst area flora and changes within Karst ecosystems is needed. Second, research on the mechanisms involved in habitat maintenance serves as the basis of the establishment of regional diversity surveys. On this basis, research related to maintaining diversity in light of economic development should be added with discussions on issues such as population variation and the ability of populations to evolve as well as changes in regional biodiversity on both the macro and microlevels. Third, species selection during habitat reconstruction is very subjective. If we want to balance economic development with ecological benefits, we need to study how we can coordinate the relationships among species in the reconstruction area, and maintain stable regional biodiversity. Last, designing a monitoring system is an important basis for status surveys and prediction of future conditions. Monitoring might provide scientific data to help maintain biological diversity in Karst areas.