189 research outputs found
Recommended from our members
Chapter 6, Figure 6.12
https://scholarworks.umass.edu/umpress_tidal_wetlands_primer_images/1046/thumbnail.jp
Recommended from our members
Chapter 1, Figure 1.6
https://scholarworks.umass.edu/umpress_tidal_wetlands_primer_images/1005/thumbnail.jp
Recommended from our members
Chapter 12, Figure 12.4
https://scholarworks.umass.edu/umpress_tidal_wetlands_primer_images/1087/thumbnail.jp
Wetland Trends for Selected Areas of the Casco Bay Estuary of the Gulf of Maine (1974-77 to 1984-87)
Recommended from our members
Delaware Wetlands: Status and Changes from 1992 to 2007
A report which summarizes the status of the wetlands in Delaware in 2007 as well as the changes that have taken place since 1992
1969: Abilene Christian College Bible Lectures - Full Text
GOD’S ETERNAL PURPOSE
Being the Abilene Christian College Annual Bible Lectures 1969
Published by
ABILENE CHRISTIAN COLLEGE BOOK STORE
ACC Station Abilene, Texas 7960
US Fish and Wildlife Service 1979 wetland classification: A review
In 1979 the US Fish and Wildlife Service published and adopted a classification of wetlands and deepwater habitats of the United States. The system was designed for use in a national inventory of wetlands. It was intended to be ecologically based, to furnish the mapping units needed for the inventory, and to provide national consistency in terminology and definition. We review the performance of the classification after 13 years of use. The definition of wetland is based on national lists of hydric soils and plants that occur in wetlands. Our experience suggests that wetland classifications must facilitate mapping and inventory because these data gathering functions are essential to management and preservation of the wetland resource, but the definitions and taxa must have ecological basis. The most serious problem faced in construction of the classification was lack of data for many of the diverse wetland types. Review of the performance of the classification suggests that, for the most part, it was successful in accomplishing its objectives, but that problem areas should be corrected and modification could strengthen its utility. The classification, at least in concept, could be applied outside the United States. Experience gained in use of the classification can furnish guidance as to pitfalls to be avoided in the wetland classification process
Wetland Issues Affecting Waterfowl Conservation in North America
This paper summarises discussions by invited speakers during a special session at the 6th North American Duck Symposium on wetland issues that affect waterfowl, highlighting current ecosystem challenges and opportunities for the conservation of waterfowl in North America. Climate change, invasive species, U.S. agricultural policy (which can encourage wetland drainage and the expansion of row-crop agriculture into grasslands), cost and competition for water rights, and wetland management for non-waterfowl species were all considered to pose significant threats to waterfowl populations in the near future. Waterfowl populations were found to be faced with significant threats in several regions, including: the Central Valley of California, the
Playa Lakes Region of the south-central U.S., the Prairie Pothole Region of the northern U.S. and western and central Canada, the boreal forest of northern Canada, the Great Lakes region and Latin America. Apart from direct and indirect threats to habitat, presenters identified that accurate and current data on the location, distribution and diversity of wetlands are needed by waterfowl managers, environmental planners and regulatory agencies to ensure focused, targeted and cost-effective wetland conservation. Although populations of many waterfowl species are currently at or above long-term average numbers, these populations are thought to be at risk of decline in the near future because of ongoing and predicted nesting habitat loss and wetland destruction in many areas of North America
Use of a reciprocal transplant study to measure the rate of plant community change in a tidal marsh along a salinity gradient
The relationship between environmental factors and the spatial distribution of maintained and actively used burrows of the grapsid crab Helograpsus haswellianus was studied at three saltmarsh sites in southeast Queensland, Australia. The sites had been modified by runnelling for mosquito-control, a method that transports low-amplitude tides to areas of saltmarsh. The study investigated the relationship between burrow density, burrow aperture size, and runnelling, as well as the effect of flooding or non-flooding tides and distance from a tidal source. Responses differed at the three sites. The most consistent pattern across all sites was that active burrows were most numerous between 30 and 50 m from the saltmarsh / mangrove interface at the landward side of the tidal source. At particular sites, there were significant relationships between burrow aperture size, tidal period, and the presence of runnels. Generally, few small burrows occurred low on the shore, while larger burrows were distributed across the shore to 50 m. At naturally dry sites, more burrows occurred within 5 m of the runnel, whereas at naturally wet sites, fewer burrows were found close to the runnel. As runnels transport low-amplitude tides, moisture conditions required for burrowing may very between flooding and non-flooding tides. Overall, the influence of tides on the density of crab burrows and their aperture sizes was of more importance than the presence of runnels alone
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