2.2.2 Land use and driver data
In the simulation of future land use in China, the land use data were
downloaded from the Resource and Environment Science and Data Center
(RESDC), including 2010 and 2015. Referring to the classification system
of China’s National Land Use and Cover Change (CNLUCC) (Table S2), the
land use data in 2015 were reclassified by ArcMap10.5 software,
including cultivated land, forest, grassland, waters, construction land,
and unused land. The region expressed by the classified grassland (all
kinds of grasslands with herbaceous plants and coverage of more than
5%, including shrub grassland dominated by grazing and sparse forest
grassland with canopy density of less than 10%) is consistent with the
habitat previously recorded by T. chinense , so we regarded the
grassland as the natural habitat of T. chinense . The driving
factors were divided into physical geography, human disturbance, and
bioclimate (Figure S1). Physical geographic factors included elevation
(WorldClim Database v2.1), soil erosion (RESDC), and distance from
water. Distance from the water was calculated based on water system data
(RESDC) using the EuclideanDistance tool in ArcMap10.5. Human
disturbance factors included the population data and GDP data of 2015
were downloaded from the RESDC and the distance from road and railway
(DRA) calculated by EuclideanDistance tool based on the road data and
railway data of RESDC. Bioclimatic factors included annual precipitation
and mean temperature data from WorldClim Database v2.1 in 2015. All the
above data layers used the Resample tool in ArcMap10.5 to unify the data
resolution to 2.5 min.