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Beavers (Castor canadensis Kuhl) can influence the competitive dynamics of plant species through selective foraging, collection of materials for dam creation, and alteration of hydrologic conditions. In the Grand Canyon National Park, the native Salix gooddingii C.R.Ball (Goodding?s willow) and Salix exigua Nutt. (coyote willow) are a staple food of beavers. Because Salix competes with the invasive Tamarix ramosissima Ledeb., land mangers are concerned that beavers may cause an increase in Tamarix through selective foraging of Salix. A spatial analysis was conducted to assess whether the presence of beavers correlates with the relative abundance of Salix and Tamarix. These methods were designed to detect a system-wide...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Castor canadensis,
Colorado River,
Salix,
Springer Netherlands,
Wetlands, All tags...
herbivory,
plant-animal interactions,
riparian vegetation,
tamarisk, Fewer tags
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Aim A regional analysis was used to explore the influence of river regulation on the dominance of non-native, invasive shrubs and trees. We addressed the following questions: (1) How do large dams affect hydrological parameters that influence riparian vegetation? (2) How do flow regimes affect the dominance of non-native woody species? (3) How do changes in flow regimes affect the dominance of non-native woody species? Location South-western USA. Methods We sampled the canopy cover of woody species on 179 point bars along seven non-dammed and thirteen dammed river segments. Wilcoxon rank sum tests were used to determine differences between flow parameters in dammed and non-dammed rivers. We used correlation analyses...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Dams,
Elaeagnus,
Global Ecology and Biogeography,
Populus,
Salix, All tags...
Tamarix,
flow regimes,
hydrology,
invasions,
riparian vegetation,
south-western USA, Fewer tags
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In the southwestern US, the composition and abundance of riparian plants has changed as a result of flow regime alteration and the invasion of Tamarix. We investigated trends in vegetation dynamics along the Green and Colorado Rivers in Canyonlands National Park (CNP) from 1976 to 2008 through historical aerial photo analyses. We also explored the relationships between understory and overstory species in riparian habitat of CNP. The effects of river regulation on seedling establishment patterns were assessed in slightly regulated, moderately regulated, and extremely regulated river sections in the southwestern US. Tamarix dominated the overstory vegetation in all river sections in CNP but was less dominant along...
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