26 research outputs found
Phylogeography of the Sino-Himalayan Fern Lepisorus clathratus on “The Roof of the World”
The Qinghai-Tibetan Plateau (QTP) and its southern and southeastern mountain ranges, Himalaya-Hengduan Mountains (HHM), are one of the most extensive habitats for alpine plants in the world. How ferns occurring in QTP and HHM changed their distribution ranges in response to Quaternary climatic oscillations remains almost unknown.We employed sequences of two chloroplast DNA regions, rps4-trnS and trnL-trnF, to reconstruct phylogeography of the Sino-Himalayan fern Lepisorus clathratus, occurring mainly in the QTP and HHM. Individuals of this species have either dehiscent or indehiscent sporangia with the latter evolved from the plesiomorphic dehiscent forms. Based on a range-wide sampling, we detected 27 cpDNA haplotypes that were divided into five groups by network analyses. Populations in the Hengduan Mountains possess the highest genetic diversity, while a single haplogroup is detected across the north-central region. A distinct phylogeographical subdivision was detected between the Hengduan Mountains and north-central region by AMOVA analysis. The haplogroup distribution pattern, coalescence and AMOVA analysis suggest that a long term survival area (refugia) of the species was located in the Hengduan Mountains during glaciations, with probable range expansions into north-central regions during interglacial periods. Populations with indehiscent sporangium can carry private haplotypes and are inclined to maintain genetic homogeneity. One group with indehiscent sporangia most likely survived in situ on the QTP during glaciations.This study for the first time sheds light on the response of alpine ferns in the QTP and HHM to the Quaternary climatic oscillations
Conducting robust ecological analyses with climate data
Although the number of studies discerning the impact of climate change on ecological systems continues to increase, there has been relatively little sharing of the lessons learnt when accumulating this evidence. At a recent workshop entitled ‘Using climate data in ecological research’ held at the UK Met Office, ecologists and climate scientists came together to discuss the robust analysis of climate data in ecology. The discussions identified three common pitfalls encountered by ecologists: 1) selection of inappropriate spatial resolutions for analysis; 2) improper use of publically available data or code; and 3) insufficient representation of the uncertainties behind the adopted approach. Here, we discuss how these pitfalls can be avoided, before suggesting ways that both ecology and climate science can move forward. Our main recommendation is that ecologists and climate scientists collaborate more closely, on grant proposals and scientific publications, and informally through online media and workshops. More sharing of data and code (e.g. via online repositories), lessons and guidance would help to reconcile differing approaches to the robust handling of data. We call on ecologists to think critically about which aspects of the climate are relevant to their study system, and to acknowledge and actively explore uncertainty in all types of climate data. And we call on climate scientists to make simple estimates of uncertainty available to the wider research community. Through steps such as these, we will improve our ability to robustly attribute observed ecological changes to climate or other factors, while providing the sort of influential, comprehensive analyses that efforts to mitigate and adapt to climate change so urgently require
Global distribution of a wild bee subfamily, Colletinae
Bee data were assembled from various digital resources and unpublished
original data digitized by the authors and checked for taxonomic and geographic
errors.<div>Reference: Bystriakova N, Griswold T, Ascher JS, Kuhlmann M (2017) Key environmental determinants of global and regional richness and endemism patterns for a wild bee subfamily. Biodivers Conserv. doi: 10.1007/s10531-017-1432-7</div
Matrix of vascular plant species observations at 141 points in La Amistad Binational Park
Matrix of vascular plant species observations at 141 points in La Amistad Binational Park including three associated spreadsheets. 'Matrix' sheet is the matrix with species names shortened to 8 characters. 'Variables' sheet are the geographical coordinates, elevation, slope and climate variables for each sample point. 'Plot coords' are the geographical coordinates for each sample point. 'Short names' are the full binomials for the abbreviated species names used in the matrix
Sampling bias in geographic and environmental space and its effect on the predictive power of species distribution models
Despite ever-growing popularity of species distribution models (SDM), their performance under conditions of spatially biased data has rarely been studied in detail. Here we explore the effect of a known spatial bias on the predictive ability of Maxent models, using five species of the genus Asplenium with variable reproductive modes. The models were trained and tested on western and central European presence-only distributional data, first with random background and then with target-group background. Then we tested the models on an independent Ukrainian dataset of the same species, using the area under the curve (AUC) value as test statistic. We carried out a principal components analysis (PCA) on the collection localities of the individual species to explore the properties of their ecological niches. In all but one species, spatial bias in the distributional data resulted in poor performance of the Maxent models (trained on the European dataset and tested on the Ukrainian dataset). In all species correction for sampling bias resulted in significantly wider predicted climatic niches. Based on the results of the PCA, spatial bias resulted in environmental bias of variable degree. We argue that species reproductive biology should be taken into account when distributional data are analysed in terms of their suitability for species distribution modelling. The reported results will inform biodiversity conservation assessments, particularly those using data from natural history collections
Discovery of a diverse cave flora in China
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 plants occupy in caves is not distinct from non-cave habitats. To do so we surveyed 61 caves and used species accumulation curves (SAC) to estimate the total diversity of this flora and used a subsample of 14 caves to characterise the light environment. We used regional floras and existing conservation assessments to evaluate the conservation value of this flora. We used observations on human disturbance within caves to evaluate anthropogenic activities. Four-hundred-and-eighteen vascular plant species were documented with SACs predicting a total diversity of 529–846. Ninety-three percent of the species documented are known karst forest species, 7% are endemic to caves and 81% of the species are angiosperms. We demonstrate that the light environment in caves is distinct to that of terrestrial habitats and that a subset of the flora likely grow in the lowest light levels documented for vascularised plants. Our results suggest that the proportion of species threatened with extinction is like that for the terrestrial habitat and that almost half of the entrance caverns sampled showed signs of human disturbance. We believe that this is the first time that such an extensive sample of cave flora has been undertaken and that such a diverse vascular plant flora has been observed in caves which we predict occurs elsewhere in SE Asia. We argue that the cave flora is an extension of the karst forest understory present prior to catastrophic deforestation in the 20thC. We suggest that within SW China caves serve as both refuges and a valuable source of germplasm for the restoration of karst forest. We also propose that caves represent a distinct habitat for plants that is most similar t