![Plant diversity in riparian forests in northwest Colorado: Effects of time and river regulation [An article from: Forest Ecology and Management]](https://www.ebooknetworking.net/books/B00/0RR/bigB000RR69BU.jpg)
Plant diversity in riparian forests in northwest Colorado: Effects of time and river regulation [An article from: Forest Ecology and Management]
Description
This digital document is a journal article from Forest Ecology and Management, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
During the 20th Century the flow of most rivers in the United States was regulated by diversions and dams, with major impacts on riparian forests. Few unregulated rivers remain to provide baseline information for assessing these impacts. We characterized patterns in riparian plant communities along chronosequences on the unregulated Yampa River and the regulated Green River in northwestern Colorado, examining patterns in plant species diversity in relation to the ages of floodplain terraces. On both rivers, mean plant species richness in cottonwood (Populus deltoides Marshall subsp. wislizenzii (Watson) Eckenwalder) dominated riparian forests declined by more than 50% from young sites (250 years). Mean species richness (number of plant species/1000m^2) was 40% higher on the unregulated Yampa River than on the regulated Green River, and 84% of the variance in total species richness related to age class, river, and tree cover. One-third of the plant species in all plots were exotic and 63% of the variance in exotic species richness was explained by a positive correlation with the richness of native species. On the Yampa and Green Rivers, ecosystem development and river regulation both reduce species richness, and these effects appear to be additive. The methods and insights from this study can be applied to other river systems to investigate the processes that change species diversity over time, and vegetation responses to the major changes in environmental conditions that follow river regulation.
Description:
During the 20th Century the flow of most rivers in the United States was regulated by diversions and dams, with major impacts on riparian forests. Few unregulated rivers remain to provide baseline information for assessing these impacts. We characterized patterns in riparian plant communities along chronosequences on the unregulated Yampa River and the regulated Green River in northwestern Colorado, examining patterns in plant species diversity in relation to the ages of floodplain terraces. On both rivers, mean plant species richness in cottonwood (Populus deltoides Marshall subsp. wislizenzii (Watson) Eckenwalder) dominated riparian forests declined by more than 50% from young sites (250 years). Mean species richness (number of plant species/1000m^2) was 40% higher on the unregulated Yampa River than on the regulated Green River, and 84% of the variance in total species richness related to age class, river, and tree cover. One-third of the plant species in all plots were exotic and 63% of the variance in exotic species richness was explained by a positive correlation with the richness of native species. On the Yampa and Green Rivers, ecosystem development and river regulation both reduce species richness, and these effects appear to be additive. The methods and insights from this study can be applied to other river systems to investigate the processes that change species diversity over time, and vegetation responses to the major changes in environmental conditions that follow river regulation.
