Using Landsat imagery to map understory shrub expansion relative to landscape position in a mid‐Appalachian watershed

摘要: Globally, shrub expansion is an important driver of ecological change. However, most studies have focused on dryland ecosystems (e.g., savannas, rangelands, grasslands), or in tundra regions arctic, alpine). shrubs play a key role other systems, such as the understory temperate forests. In Appalachian forests eastern United States, rhododendron (Rhododendron maximum) prevalent species constituent evergreen community and can affect forest diversity structure by altering light moisture regimes, changing soil chemical physical properties. We examine spatial patterns temporal dynamics layer within mid‐Appalachian over period from 1986 to 2011 using Landsat TM data explore how related landscape position elevation, aspect, distance‐to‐stream). use combination remotely sensed vegetation indices NDVI, tasseled cap indices) derived snow‐free, leaf‐off 5 surface reflectance paired with Random Forest classification model Weimer Run watershed near Canaan Valley, West Virginia, first‐order, high‐altitude watershed. show extensive increases winter greenness we attribute community. From 2011, there 0.14 increase 52% relative coverage 25 yr. Shrub notable at lower elevations, along streams, southerly oriented slopes. argue that changes abundance are due decreased limitations driven climate. There increased effort reintroduce native conifers this region, but jeopardize effort, inhibits growth dispersal these red spruce). Our results expanding into areas which they previously been restricted. Use remote sensing methods may allow better habitat suitability mapping, leading targeted restoration efforts more‐informed ecosystem forecasts.