World Forests 30m BaseVue 2013

Retirement Notice: This item is in mature support as of April 2024 and will be retired in December 2026. A replacement for this item is available for your use. Esri recommends updating your maps and apps to use the new version. Forests are provided here as an excerpted subset of the World Land Cover 30m BaseVue 2013 layer. Separating forests is useful as a cartographic layer on environmentally oriented maps and analytically as a basis for ecosystem and habitat definition. Dataset Summary BaseVue 2013 is a commercial global, land use / land cover (LULC) product developed by MDA. BaseVue covers the Earth’s entire land area, excluding Antarctica. BaseVue is independently derived from roughly 9,200 Landsat 8 images and is the highest spatial resolution (30m), most current LULC product available. The capture dates for the Landsat 8 imagery range from April 11, 2013 to June 29, 2014. The following 4 classes of forest are featured in this layer: Deciduous Forest: Trees > 3 meters in height, canopy closure >35% (<25% inter-mixture with evergreen species) that seasonally lose their leaves, except Larch. Evergreen Forest: Trees >3 meters in height, canopy closure >35% (<25% inter-mixture with deciduous species), of species that do not lose leaves. (will include coniferous Larch regardless of deciduous nature). Woody Wetlands: Areas where forest or shrubland vegetation accounts for greater than 20% of vegetative cover and the soil or substrate periodically is saturated with, or covered by water. Only used within the continental U.S. Mixed Forest: Areas dominated by trees generally greater than 5 meters tall, and greater than 20% of total vegetation cover. Neither deciduous nor evergreen species are greater than 75% of total tree cover. Only used within the continental U.S. MDA updated the underlying data in late 2016 and this service was updated in February 2017. An improved selection of cloud-free images was used to produce the update, resulting in improvement of classification quality to 80% of the tiles for this service.退役声明：本数据集自2024年4月起进入成熟支持阶段，并将于2026年12月正式停用。目前已有替代产品可供使用，Esri建议您更新相关地图与应用，以适配新版产品。 本森林数据集为《World Land Cover 30m BaseVue 2013》图层的节选子集。将森林要素单独提取，可作为环境类地图的制图图层，也可作为生态系统与栖息地定义的分析基础。 数据集摘要：BaseVue 2013是MDA开发的商用全球土地利用/土地覆盖（Land Use/Land Cover, LULC）产品。该数据集覆盖除南极洲以外的全球全部陆地区域，独立基于约9200景陆地卫星8号（Landsat 8）影像生成，是当前空间分辨率最高（30米）、时效性最强的LULC产品。所用Landsat 8影像的采集时间范围为2013年4月11日至2014年6月29日。 本图层包含以下4类森林： 1. 落叶阔叶林（Deciduous Forest）：树高超过3米、树冠覆盖率大于35%（与常绿树种混交比例低于25%）且季节性落叶的林分，落叶松除外。 2. 常绿林（Evergreen Forest）：树高超过3米、树冠覆盖率大于35%（与落叶树种混交比例低于25%）且终年不落叶的林分（无论落叶特性，均包含针叶落叶松）。 3. 木本湿地（Woody Wetlands）：森林或灌丛植被占植被覆盖比例超过20%，且土壤或基质周期性被水饱和或淹没的区域。该类别仅适用于美国本土地区。 4. 混交林（Mixed Forest）：以树高普遍超过5米的树木为主，且树木占总植被覆盖比例大于20%的区域。落叶树种与常绿树种占比均未超过总树木覆盖的75%。该类别仅适用于美国本土地区。 MDA于2016年末更新了基础数据，本服务亦于2017年2月完成更新。本次更新选用了更优质的无云影像，使得本服务的分类质量提升至80%的瓦片覆盖范围。