Landscape fragmentation Effective Mesh Density time-series, 2009: major and medium anthropogenic fragmenting elements (FGA2-S) - version 1.0, Nov. 2019

This dataset is the new version of the Effective Mesh Density (seff) 2016 dataset with improved input data, for the year 2009. This new dataset uses the Copernicus Imperviousness and the TomTom TeleAtlas datasets as fragmenting geometries.

The Effective Mesh Density (seff) is a measure of the degree to which movement between different parts of the landscape is interrupted by a Fragmentation Geometry (FG). FGs are defined as the presence of impervious surfaces and traffic infrastructure, including medium sized roads. The more FGs fragment the landscape, the higher the effective mesh density hence the higher the fragmentation. The geographic coverage of the dataset is EEA39 except these countries: Albania, Bosnia and Herzegovina, Cyprus, Iceland, Kosovo (UNSCR 1244/99), Montenegro, North Macedonia, Romania, Serbia and Türkiye.

An important consequence of landscape fragmentation is the increased isolation of ecosystem patches that breaks the structural connections and decreases resilience and ability of habitats to provide various ecosystem services. Fragmentation also influences human communities, agriculture, recreation and overall quality of life. Monitoring how fragmentation decreases landscape quality and changes the visual perception of landscapes provides information for policy measures that aim at improving ecosystem condition and restoration as well as maintaining the attractiveness of landscapes for recreational activities.

本数据集为2016版有效网格密度（Effective Mesh Density, seff）数据集的更新版本，优化了输入数据，对应研究年份为2009年。新版数据集采用哥白尼不透水面（Copernicus Imperviousness）数据集与TomTom TeleAtlas数据集作为破碎化几何数据源。

有效网格密度（seff）是衡量景观不同区域间的移动被破碎化几何（Fragmentation Geometry, FG）阻断程度的指标。破碎化几何指不透水面与包括中等规模道路在内的交通基础设施的存在。景观被破碎化几何分割的程度越高，有效网格密度便越高，景观破碎化程度也就越强。本数据集的地理覆盖范围为EEA39区域，但不包含以下国家：阿尔巴尼亚、波斯尼亚和黑塞哥维那、塞浦路斯、冰岛、科索沃（联合国安理会第1244/1999号决议框架下）、黑山、北马其顿、罗马尼亚、塞尔维亚及土耳其（Türkiye）。

景观破碎化的一项重要影响是生态系统斑块的隔离程度加剧，这会破坏景观的结构连接性，降低生境提供各类生态系统服务的韧性与能力。破碎化同时也会对人类社区、农业、休闲活动及整体生活质量产生影响。通过监测破碎化如何降低景观质量、改变景观视觉观感，可为旨在改善生态系统状况、开展生态修复以及维持景观休闲吸引力的政策举措提供决策依据。