Using Landsat imagery to map understory shrub expansion relative to landscape position in a mid‐Appalachian watershed
Abstract Globally, shrub expansion is an important driver of ecological change. However, most studies of shrub expansion have focused on dryland ecosystems (e.g., savannas, rangelands, grasslands), or in tundra regions (e.g., arctic, alpine). However, shrubs play a key role in other systems, such as...
Published in: | Ecosphere |
---|---|
Main Authors: | , , |
Other Authors: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2018
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1002/ecs2.2404 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fecs2.2404 https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1002/ecs2.2404 |
id |
crwiley:10.1002/ecs2.2404 |
---|---|
record_format |
openpolar |
spelling |
crwiley:10.1002/ecs2.2404 2024-09-09T19:27:55+00:00 Using Landsat imagery to map understory shrub expansion relative to landscape position in a mid‐Appalachian watershed Atkins, Jeff W. Epstein, Howard E. Welsch, Daniel L. University of Virginia 2018 http://dx.doi.org/10.1002/ecs2.2404 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fecs2.2404 https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1002/ecs2.2404 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Ecosphere volume 9, issue 10 ISSN 2150-8925 2150-8925 journal-article 2018 crwiley https://doi.org/10.1002/ecs2.2404 2024-06-20T04:22:24Z Abstract Globally, shrub expansion is an important driver of ecological change. However, most studies of shrub expansion have focused on dryland ecosystems (e.g., savannas, rangelands, grasslands), or in tundra regions (e.g., arctic, alpine). However, shrubs play a key role in other systems, such as the understory of temperate forests. In the Appalachian forests of the eastern United States, rhododendron ( Rhododendron maximum ) is the most prevalent species constituent of the understory evergreen shrub community and can affect forest diversity and structure by altering light and moisture regimes, and changing soil chemical and physical properties. We examine the spatial patterns and temporal dynamics of the evergreen shrub layer within a mid‐Appalachian forest over the period from 1986 to 2011 using Landsat TM data to explore how shrub expansion is related to landscape position (e.g., elevation, aspect, and distance‐to‐stream). We use a combination of remotely sensed vegetation indices (e.g., NDVI , tasseled cap indices) derived from snow‐free, leaf‐off Landsat 5 surface reflectance data from 1986 to 2011 paired with a Random Forest classification model to examine shrub dynamics in the Weimer Run watershed near Canaan Valley, West Virginia, a first‐order, high‐altitude watershed. We show extensive increases in winter greenness we attribute to expansion of the evergreen shrub community. From 1986 to 2011, there is a 0.14 increase in winter NDVI , with a 52% relative increase in shrub coverage over 25 yr. Shrub expansion is most notable at lower elevations, along streams, and on southerly oriented slopes. We argue that changes in shrub abundance are due to decreased moisture limitations driven by changing climate. There is an increased effort to reintroduce native conifers to this region, but changes in the shrub community jeopardize this effort, as rhododendron inhibits the growth and dispersal of these conifers (e.g., red spruce). Our results show that rhododendron shrubs are expanding into areas of the forest ... Article in Journal/Newspaper Arctic Tundra Wiley Online Library Arctic Ecosphere 9 10 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Abstract Globally, shrub expansion is an important driver of ecological change. However, most studies of shrub expansion have focused on dryland ecosystems (e.g., savannas, rangelands, grasslands), or in tundra regions (e.g., arctic, alpine). However, shrubs play a key role in other systems, such as the understory of temperate forests. In the Appalachian forests of the eastern United States, rhododendron ( Rhododendron maximum ) is the most prevalent species constituent of the understory evergreen shrub community and can affect forest diversity and structure by altering light and moisture regimes, and changing soil chemical and physical properties. We examine the spatial patterns and temporal dynamics of the evergreen shrub layer within a mid‐Appalachian forest over the period from 1986 to 2011 using Landsat TM data to explore how shrub expansion is related to landscape position (e.g., elevation, aspect, and distance‐to‐stream). We use a combination of remotely sensed vegetation indices (e.g., NDVI , tasseled cap indices) derived from snow‐free, leaf‐off Landsat 5 surface reflectance data from 1986 to 2011 paired with a Random Forest classification model to examine shrub dynamics in the Weimer Run watershed near Canaan Valley, West Virginia, a first‐order, high‐altitude watershed. We show extensive increases in winter greenness we attribute to expansion of the evergreen shrub community. From 1986 to 2011, there is a 0.14 increase in winter NDVI , with a 52% relative increase in shrub coverage over 25 yr. Shrub expansion is most notable at lower elevations, along streams, and on southerly oriented slopes. We argue that changes in shrub abundance are due to decreased moisture limitations driven by changing climate. There is an increased effort to reintroduce native conifers to this region, but changes in the shrub community jeopardize this effort, as rhododendron inhibits the growth and dispersal of these conifers (e.g., red spruce). Our results show that rhododendron shrubs are expanding into areas of the forest ... |
author2 |
University of Virginia |
format |
Article in Journal/Newspaper |
author |
Atkins, Jeff W. Epstein, Howard E. Welsch, Daniel L. |
spellingShingle |
Atkins, Jeff W. Epstein, Howard E. Welsch, Daniel L. Using Landsat imagery to map understory shrub expansion relative to landscape position in a mid‐Appalachian watershed |
author_facet |
Atkins, Jeff W. Epstein, Howard E. Welsch, Daniel L. |
author_sort |
Atkins, Jeff W. |
title |
Using Landsat imagery to map understory shrub expansion relative to landscape position in a mid‐Appalachian watershed |
title_short |
Using Landsat imagery to map understory shrub expansion relative to landscape position in a mid‐Appalachian watershed |
title_full |
Using Landsat imagery to map understory shrub expansion relative to landscape position in a mid‐Appalachian watershed |
title_fullStr |
Using Landsat imagery to map understory shrub expansion relative to landscape position in a mid‐Appalachian watershed |
title_full_unstemmed |
Using Landsat imagery to map understory shrub expansion relative to landscape position in a mid‐Appalachian watershed |
title_sort |
using landsat imagery to map understory shrub expansion relative to landscape position in a mid‐appalachian watershed |
publisher |
Wiley |
publishDate |
2018 |
url |
http://dx.doi.org/10.1002/ecs2.2404 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fecs2.2404 https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1002/ecs2.2404 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Tundra |
genre_facet |
Arctic Tundra |
op_source |
Ecosphere volume 9, issue 10 ISSN 2150-8925 2150-8925 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1002/ecs2.2404 |
container_title |
Ecosphere |
container_volume |
9 |
container_issue |
10 |
_version_ |
1809897238740074496 |