1. 首页
  2. 机构
  3. USDA Forest Service
  4. Cumulative Yellow-Cedar Decline

Cumulative Yellow-Cedar Decline

Data represent presence/absence for cedar decline is occurrence Cedar decline refers to the dying or decline of yellow-cedar (Chamaecyparis nootkatensis) forests in Southeast Alaska and is characterized by red or yellow foliage in trees currently dying, or by white-gray snags of old mortality. Mapped snags can be standing dead as long as eighty years. The data were collected via aerial sketch mapping techniques and recorded on 1:250,000 USGS base maps from 500-3000 foot above ground level(AGL) observations. Survey coverage has been most intense for forests adjacent to shorelines and waterways. Data are collected, refined and updated on an annual basis. This data represent not one year's mortality but the cumulative effect seen from the air.

数据与资源

其他信息

域 价值
最近更新 十二月 17, 2019, 10:30 (AKST)
创建的 十二月 17, 2019, 10:30 (AKST)
状态 Complete
Start Date 2012-08-02
End Date 2012-08-02