Ecogeographical variable dataset for species distribution modelling, describing forest landscape in Latvia, 2017

42 ecogeographical variables (EGVs) used to describe the landscape of Latvia at three scales (local and two landscape). Layers are focused on the description of forest heterogeneity, but account for other ecosystems and land cover types as well. The more temporarily changing land use and land cover (LULC) types as forest and agricultural lands are described from 2017 databases. With most of the other LULC information gathered from the topographic map (2016) at the scale of 1:10 000.
All the raster layers provided here are in the Latvian projected coordinate reference system (epsg:3059) with a grid cell size of 25ha. Each layer provides quantitative information on the area, shape, and edge of habitat classes and additionally, age, time since the last forestry disturbance, relative soil humidity, relative soil richness etc. for forests. The three scales represent information from within 25ha grid cell, and two radii – 1250 and 2500 m - around the center of the grid cell.

42个生态地理变量（ecogeographical variables, EGVs）用于刻画拉脱维亚在三种尺度（局地尺度与两种景观尺度）下的景观特征。本次数据集的图层以描述森林异质性为核心，同时涵盖其他生态系统与土地覆被类型。其中动态性较强的土地利用与土地覆被（land use and land cover, LULC）类型，如林地与农用地，均基于2017年数据库进行表征；其余多数土地利用与土地覆被信息则源自比例尺为1:10000的2016年地形图。
本次提供的全部栅格图层均采用拉脱维亚投影坐标系（epsg:3059），栅格单元尺寸为25公顷。每个图层不仅量化了生境类别的面积、形状与边缘特征，还针对森林生境补充了林龄、末次林业扰动后的时长、相对土壤湿度、相对土壤肥力等相关参数。三种尺度分别对应25公顷栅格单元内部的信息，以及以该栅格单元中心为原点、半径分别为1250米与2500米的缓冲范围内的信息。