2.1 Data Collection and Preprocessing of Distribution
Point Data
A total of 199 distribution records of T. sinense were sourced
from various data platforms, including Flora Reipublicae Popularis
Sinicae (http://iplant.cn/), Plant Photo Bank of China, and the Global
Biodiversity Information Facility (GBIF, http://www.gbif.org).
Additionally, our research group conducted field investigations,
yielding 121 distribution data points. Consequently, a comprehensive
dataset comprising 320 distribution records of T. sinense was
compiled.
The coordinate points of T. sinense , denoted by latitude and
longitude, were converted into decimal numbers compatible with ARCGIS
using standard formulas. The resulting table contained three columns:
space, longitude, and latitude, and was stored in CSV format.
Subsequently, the distribution data in CSV format were imported into
ARCGIS 10.2. By utilizing the ”Data/Display XY data” and ”Data/Export
data” functions, a vector file representing the distribution points ofT. sinense was generated. The projection utilized the WGS1984
geographic coordinate system, with each grid layer retaining only one
distribution point. This process ensured an accuracy of 2.5 m,
facilitated by ENMTTools software. Following the removal of duplicate
entries and the mitigation of sampling deviations, a final set of 232
distribution points was selected (Fig. 1).