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Full-Text Articles in Physical Sciences and Mathematics
13.4.1. Considerations Of Community Characteristics For Sampling Vegetation, Leigh H. Fredrickson, Frederic A. Reid
13.4.1. Considerations Of Community Characteristics For Sampling Vegetation, Leigh H. Fredrickson, Frederic A. Reid
Waterfowl Management Handbook
Wetland managers often monitor marsh vegetation to determine if management goals have been met and expenditures justified. Vegetation can be monitored using indices that identify plant composition, trends in vegetative changes, or rough estimates of food production. Development of vegetation sampling protocol requires careful assessment of management goals in relation to benefits received from sampling efforts. Assessing the results of manipulations has direct management implications, whereas detailed studies that emphasize plant life histories or basic ecological investigations have less direct value. Information on plant community characteristics that will enable managers to match sampling techniques with refuge needs and the constraints …
13.4.10. Control Of Willow And Cottonwood Seedlings In Herbaceous Wetlands, Leigh H. Fredrickson, Frederic A. Reid
13.4.10. Control Of Willow And Cottonwood Seedlings In Herbaceous Wetlands, Leigh H. Fredrickson, Frederic A. Reid
Waterfowl Management Handbook
Willow and cottonwood are common species in forested wetlands and occur throughout most riparian and floodplain habitats of North America. These woody species are especially common in early successional stands where seasonal flooding occurs regularly. Cottonwood and willow are often considered problem plants, because they rapidly invade wetlands dominated by herbaceous flora and can form dense, extensive stands. The shade created by these species eliminates herbaceous undergrowth, and once the sapling stage is reached, cottonwoods and willows are difficult to eradicate. Control of these species can be costly and varies considerably with latitude.
13.4.9. Preliminary Considerations For Manipulating Vegetation, Leigh H. Fredrickson, Frederic A. Reid
13.4.9. Preliminary Considerations For Manipulating Vegetation, Leigh H. Fredrickson, Frederic A. Reid
Waterfowl Management Handbook
A wide diversity of plants has adapted to the dynamic nature of wetlands. The continually changing floral landscape is shaped by physical or abiotic components that include climate, fire, soil, and water. Water quantity, quality, and chemistry have a dominating influence on wetlands as do factors such as hydroperiod (period when soils are saturated) and hydrological regime. Other factors that may affect the abundance, structure, and species composition of macrophytes or robust emergents are natural grazing, disease, and interspecific plant competition.
Vegetation is important to waterfowl for producing seeds, tubers, and browse; providing nest sites; and serving as substrates for …
13.1.1. Nutritional Values Of Waterfowl Foods, Leigh H. Fredrickson, Frederic A. Reid
13.1.1. Nutritional Values Of Waterfowl Foods, Leigh H. Fredrickson, Frederic A. Reid
Waterfowl Management Handbook
Over 40 species of North American waterfowl use wetland habitats throughout their annual cycles. Survival, reproduction, and growth are dependent on the availability of foods that meet nutritional requirements for recurring biological events. These requirements occur among a wide variety of environmental conditions that also influence nutritional demands. Recent work on nesting waterfowl has identified the female’s general nutrient needs for egg laying and incubation. Far less is known about nutritional requirements for molt and other portions of the life cycle, particularly those during the non-breeding season. Although information on specific requirements for amino acids and micronutrients of wild birds …
Complete Waterfowl Management Handbook
Complete Waterfowl Management Handbook
Waterfowl Management Handbook
The North American Waterfowl Management Plan, the Service's most recent mandate for management of migratory waterfowl, and recent legislation such as the Farm Bill all underscore the need for a single source of information about the management of waterfowl and their habitat. Much of this information exists in scientific papers, unpublished reports, or has never been recorded, and thus is not readily accessible by waterfowl managers. The need for a waterfowl management handbook was originally suggested to the Office of Information Transfer by personnel in the Service's north-central region. A prototype handbook was developed in 1987 and critiqued by 38 …
13.2.1. Waterfowl Use Of Wetland Complexes, Leigh H. Fredrickson, Frederic A. Reid
13.2.1. Waterfowl Use Of Wetland Complexes, Leigh H. Fredrickson, Frederic A. Reid
Waterfowl Management Handbook
Waterfowl are a diverse group of birds that have widely divergent requirements for survival and recruitment. Whistling-ducks, geese, and swans (Anserinae) and ducks (Anatinae) have contrasting life history requirements.
Several goose populations have expanded greatly despite extensive continental wetland losses and degradation. Most expanding populations nest in arctic areas where modifications or disturbance of nesting habitats have been minimal. These grazers often find suitable migratory and wintering habitats in terrestrial or agricultural environments. In contrast, ducks are less terrestrial and populations are influenced more by wetland characteristics, such as quality, total area of wetland basins, and size and configuration of …
13.3.1. Invertebrate Response To Wetland Management, Leigh H. Fredrickson
13.3.1. Invertebrate Response To Wetland Management, Leigh H. Fredrickson
Waterfowl Management Handbook
By gaining greater understanding and appreciation of wetland environments, managers have developed creative insights for waterfowl conservation. Among the most exciting new developments in the understanding of functional wetlands has been the recognition of the important roles of invertebrates in aquatic ecosystems. These roles include trophic linkage from primary production to secondary consumers such as waterfowl, packaging of specific nutritional components such as amino acids and micronutrients for vertebrate predators, and detrital processing of wetland organic material. Although specific invertebrate responses to various management techniques are not always predictable and may differ among invertebrate species, patterns related to water regimes, …
13.3.2. Initial Considerations For Sampling Wetland Invertebrates, Leigh H. Fredrickson, Frederic A. Reid
13.3.2. Initial Considerations For Sampling Wetland Invertebrates, Leigh H. Fredrickson, Frederic A. Reid
Waterfowl Management Handbook
As the importance of invertebrates to waterbird nutrition and detrital processing has become increasingly evident, the need for effective and efficient invertebrate sampling has grown. Identification of invertebrate responses to management requires sampling and selection of appropriate sampling equipment. Goals must be established according to qualitative or quantitative needs, organism characteristics, and wetland types. Management objectives often can be met by sampling specific invertebrates to index the effect of management rather than through long-term studies requiring large sample sizes and intensive effort. Certain wetland and invertebrate characteristics that should be considered when initiating invertebrate sampling are described below.