DOI: 10.5061/dryad.v15dv41s4
title: Steep topography buffers threatened gymnosperm species against anthropogenic pressures in China

description: China is one of the most species-rich countries in the world, harbouring
 many rare gymnosperms. Following recent human-led loss of forests, China
 is now experiencing increases in forest cover resulting from efforts of
 reforestation-schemes. As anthropogenic activities have previously been
 found to interact with topography in shaping forest cover in China and
 considering the large human population and the ongoing population increase
 of the country, it is important to understand the role of anthropogenic
 pressures relative to environmental drivers for shaping species
 distributions here. Based on the well-established relationship between
 human population density and topography, we propose a hypothesis for
 explaining species distributions in a country dominated by human
 activities, predicting that species are more likely to occur in areas of
 steep topography under medium human population densities compared to low-
 and high human population densities. Using species occurrence data from
 the Chinese Vascular Plant Distribution Database along with a common SDM
 method (Maximum Entropy Modelling) we tested this hypothesis. Our results
 show that steep topography has the highest importance for predicting
 Chinese gymnosperm species occurrences in general, and threatened species
 specifically, in areas of medium human population densities. Consequently,
 these species are more often found in areas of steep terrain, supporting
 the proposed hypothesis. Results from this study highlight the need to
 include topographically heterogeneous habitats when planning new protected
 areas for species conservation.
description: The species data were obtained from the <i>Chinese Vascular
 Plant Distribution Database</i>. The database has been assembled
 over the last 10 years by the Biodiversity and Biosafety Group at the
 Institute of Botany, Chinese Academy of Sciences. The database consists of
 native species occurrence records collected in the period 1900 – present
 time, with the majority of collections made after 1950, from both museum
 inventory reports and published literature such as floras and checklists
 at a national, provincial, and regional level (Huang <i>et
 al.</i>, 2011). Standardization of taxonomic names in the database
 was done according to <i>Catalogue of Life China</i>
 (Checklist 2015, http://www.sp2000.org.cn/) and <i>Flora of China</i> (http://foc.eflora.cn/).  For this study, only gymnosperm species were considered and the dataset used here contains 243 species at species and sub-species level (covering all Chinese gymnosperms). Species occurrences are represented at the county level (2380 counties), and each occurrence is considered a presence.
description: The excell sheet contains presence data for all gymnosperm
 species in China. Ones in the dataset indicate a species presence. Zeros
 in the dataset do <strong>not</strong> indicate true
 presences. Presences are recorded for all chinese counties, and each of
 these counties is represented by a county code ('CNTY_CODE').
 Each county is likewise associated by the point location of the county
 centroid in WGS84 latitude and longitude coordinates (columns
 'Lon' and 'Lat').