National land-cover pattern data

Land cover and its spatial patterns are key ingredients in ecological studies that consider large regions and the impacts of human activities. Because land-cover maps show only cover types and their locations, further processing is needed to extract pattern information and to characterize its spatial variability. We are producing a nationally consistent spatial database of six land-cover pattern indices: forest area density, forest connectivity, the U index (a measure of general land-use pressure by humans), land-cover connectivity, land-cover diversity, and landscape pattern types. We use the land-cover maps produced by the Multi-resolution Land Characteristics Consortium for the conterminous United States at 30-m resolution. The goal of this paper is to encourage use of the pattern data as: contextual information and independent variables for studies involving a set of field sites; indicators of landscape conditions for ecological assessments; and dependent variables in biogeographic and socioeconomic models. The new maps will be most useful in studies that require consistent and comparable land-cover pattern measurements over large regions and can be combined with the original land-cover maps and other data.

土地覆被及其空间格局，是开展大尺度区域生态研究与人类活动影响分析的核心组成要素。由于常规土地覆被地图仅能展示覆被类型及其空间分布位置，需经进一步处理方可提取格局信息并表征其空间变异性。本研究正构建一套全国统一的空间数据库，涵盖六项土地覆被格局指数：森林面积密度、森林连通性、U指数（用于衡量人类总体土地利用压力）、土地覆被连通性、土地覆被多样性及景观格局类型。本研究采用多分辨率土地特征联盟（Multi-resolution Land Characteristics Consortium）制作的美国本土30米分辨率土地覆被地图。本文旨在推广该格局数据的三类应用场景：作为多野外站点研究的背景信息与自变量、生态评估中的景观状况指示因子，以及生物地理与社会经济模型中的因变量。这套全新的格局数据集，在需要对大尺度区域开展统一且可比较的土地覆被格局测量的研究中具备极高应用价值，且可与原始土地覆被地图及其他数据集进行融合使用。