Download or read book Effects of Migratory Geese on Plant Communities and Nitrogen Dynamics in an Alaskan Salt Marsh written by Amy Beach Zacheis and published by . This book was released on 2000 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Herbivory is an integral component of ecosystems that impacts plant communities and ecosystem processes, and affects forage availability and quality for the herbivore. I investigated the effects of lesser snow geese (Anser caerulescens caerulescens) and Canada geese (Branta canadensis) on two salt marsh communities, a sedge meadow and an herb meadow, in Cook Inlet, Alaska. Geese used the marshes during spring migration for a brief period, and foraging intensity was low compared to other goose-grazing systems. Seventy percent of the snow goose diet was on belowground plant tissues, whereas 92% of the Canada goose diet was on aboveground shoots. In the sedge meadow, where feeding was primarily on aboveground shoots, there was no effect of grazing on biomass of the dominant species Carex ramenskii and Triglochin maritimum, or on shoot nitrogen concentrations in these species (an index of forage quality). An experiment with captive geese found no effect of herbivory on biomass or nitrogen concentrations at foraging intensity ten times greater than that imposed by wild geese, indicating that this community is highly resilient to herbivory. In the herb meadow, where snow geese fed on belowground tissues, biomass of Plantago maritima and Potentilla egedii was lower, and biomass of Carex ramenskii higher, on grazed compared to ungrazed plots. Plant species' response to herbivory was determined by plant growth form, the type of herbivory (above- or belowground), and competitive interactions. Light herbivore pressure in this community altered the relative abundance of forage species for geese. In the sedge meadow community, geese increased nitrogen mineralization rates by trampling litter into wet soils. Litter incorporated into soils increased organic nitrogren pool size, decreased soil C:N ratios, and facilitated the growth of nitrogen-fixing cyanobacteria, all of which led to increased mineralization rates in grazed areas. Fecal nitrogren inputs were small and did not affect nitrogen availability. A captive goose experiment found that fecal additions ten-fold larger also had no effect on nitrogen availability. In the herb meadow, geese did not affect nitrogen mineralization because soils were dry with little standing water, so that incorporation of litter into soils through trampling was less important"--Leaves iii-iv.
Download or read book Human Impacts on Salt Marshes written by Brian R. Silliman and published by Univ of California Press. This book was released on 2009-06-03 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Human Impacts on Salt Marshes provides an excellent global synthesis of an important, underappreciated environmental problem and suggests solutions to the diverse threats affecting salt marshes."—Peter B. Moyle, University of California, Davis
Download or read book Large Herbivore Ecology Ecosystem Dynamics and Conservation written by Kjell Danell and published by Cambridge University Press. This book was released on 2006-05-25 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most large herbivores require some type of management within their habitats. Some populations of large herbivores are at the brink of extinction, some are under discussion for reintroduction, whilst others already occur in dense populations causing conflicts with other land use. Large herbivores are the major drivers for forming the shape and function of terrestrial ecosystems. This 2006 book addresses the scientifically based action plans to manage both the large herbivore populations and their habitats worldwide. It covers the processes by which large herbivores not only affect their environment (e.g. grazing) but are affected by it (e.g. nutrient cycling) and the management strategies required. Also discussed are new modeling techniques, which help assess integration processes in a landscape context, as well as assessing the consequences of new developments in the processes of conservation. This book will be essential reading for all involved in the management of both large herbivores and natural resources.
Download or read book Herbivore mediated Effects on Ecosystem Processes in a Near Arctic Salt Marsh written by Brian Thomas Person and published by . This book was released on 2001 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Herbivores influence, and often regulate energy flow. I investigated interactions between herbivory and the foods on which geese rely while nesting and rearing their broods on the Yukon-Kuskokwim Delta in southwestern Alaska. In a captive Cackling Canada gosling (Branta Canadensis minima) experiment I decoupled the effects of seasonal declines in forage quality and availability on gosling development. An 11% decline in forage quality translated to goslings that were structurally smaller and 100 g lighter at 31 days of age. Forage availability had similar effects on gosling size, and the combined magnitude of these effects are similar to those observed in wild populations. I manipulated within-season grazing history of 'Carex subspathacea' swards within brood-rearing areas used by Black Brant geese (Branta bernicla nigricans). Spatial variation in forage quality and availability exceeded seasonal variation. Brant consumed over 95% of the annual aboveground production of these swards without any short- or apparent long-term effects on aboveground growth. Adding grazing pressure to 'C. ramenskii, ' or removing grazing pressure from 'C. subspathacea, ' resulted in a bi-directional shift in the morphology and nutritional characteristics of these sedges. The areal extent of 'C. subspathacea' increased 2 to 8% of the Tutakoke landscape with a concomitant decrease in 'C. ramenskii' meadows between 1991-1998. Brant have been increasing the carrying capacity of the Tutakoke River colony following a population decline in the early 1980's. The population has increased beginning in 1988, yet remains below historic numbers. Density-dependent effects on gosling growth accompanied the population increase initially. However, gosling mass has increased over the past decade due to herbivore-mediated increases in the areal extent of grazing lawns"--Leaves iii-iv.
Download or read book The Wetlands Handbook 2 Volume Set written by Edward Maltby and published by John Wiley & Sons. This book was released on 2009-07-23 with total page 800 pages. Available in PDF, EPUB and Kindle. Book excerpt: Forty-two chapters by international experts from a wide range ofdisciplines make The Wetlands Handbook the essential toolfor those seeking comprehensive understanding of the subject. Adeparture from more traditional treatises, this text examinesfreshwater wetland ecosystem science from the fundamentals toissues of management and policy. Introductory chapters address the scope and significance ofwetlands globally for communities, culture and biodiversity.Subsequent sections deal with processes underpinning wetlandfunctioning, how wetlands work, their uses and values for humansand nature, their sensitivity to external impacts, and how they maybe restored. The text is illustrated by numerous examples,emphasising functional and holistic approaches to wetlandmanagement, including case studies on the wise use andrehabilitation of wetlands in farmed, urban, industrial and otherdamaged environments, highlighting the long-term benefits ofmultiple use. The Wetlands Handbook will provide aninvaluable reference for researchers, managers, policy-makers andstudents of wetland sciences.
Download or read book The Impact of Nutrient Loading on Nitrogen Removal and Carbon Dynamics in a Juncus Roemerianus and Spartina Alterniflora Dominated Salt Marsh in the Northern Gulf of Mexico written by Taylor Ledford and published by . This book was released on 2019 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increased anthropogenic nutrient loading of nitrogen (N) and phosphorus (P) to estuaries and bays can lead to eutrophication, anoxia or hypoxia, and/or loss of native or other important species. Coastal salt marshes help to counteract eutrophication by removing excess N through microbially-mediated denitrification. One important factor that regulates salt marsh N removal is vegetation type, which affects sediment N-removal capacity by modifying redox potential and altering the microbial community structure within sediments. Additionally, plant community structure can alter carbon (C) uptake via photosynthesis and C release via sediment oxidation and organic matter degradation. A 1-year field study was conducted in a salt marsh located on Dauphin Island, AL, where we increased N and P inputs by 20 g N m-2 yr-1/ 1.25 g P m-2 yr-1 (low fertilization) and 40 g N m-2 yr-1/2.5 g P m-2 yr-1 (high fertilization) in plots dominated by either Juncus roemerianus (black needlerush) or Spartina alterniflora (smooth cordgrass). Denitrification was 5X higher in unamended J. roemerianus plots versus S. alterniflora, but denitrification in S. alterniflora was more responsive to fertilization, increasing ten-fold while denitrification in J. roemerianus plots did not respond to fertilization. Gross primary productivity (GPP) was marginally higher (~5%) in control plots of J. roemerianus than in control S. alterniflora plots. High fertilization increased GPP by 27% in S. alterniflora plots, however, GPP did not respond to fertilization in J. roemerianus plots. Additionally, ERCO2 was similar across vegetation types in control plots, and did not respond to fertilization in either vegetation type. Net ecosystem exchange was similar in J. roemerianus and S. alterniflora control plots and did not change in response to N and P additions for either vegetation type. Our results illustrate that while both J. roemerianus and S. alterniflora marshes have the capacity to withstand nutrient loading in the Gulf of Mexico via N removal, S. alterniflora dominated marshes may have a greater capacity to mitigate N inputs. Additionally, in a world with higher nutrient inputs and despite higher GPP in S. alterniflora, both vegetation types will continue to sequester C at similar rates.
Download or read book Ecological Society of America Annual Meeting Abstracts written by Ecological Society of America. Meeting and published by . This book was released on 1998 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Arctic Ecosystems in Peril written by Bruce D. J. Batt and published by . This book was released on 1997 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Doctoral Dissertations written by and published by . This book was released on 2001 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecology Abstracts written by and published by . This book was released on 1995 with total page 714 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coverage: 1982- current; updated: monthly. This database covers current ecology research across a wide range of disciplines, reflecting recent advances in light of growing evidence regarding global environmental change and destruction. Major ares of subject coverage include: Algae/lichens, Animals, Annelids, Aquatic ecosystems, Arachnids, Arid zones, Birds, Brackish water, Bryophytes/pteridophytes, Coastal ecosystems, Conifers, Conservation, Control, Crustaceans, Ecosyst em studies, Fungi, Grasses, Grasslands, High altitude environments, Human ecology, Insects, Legumes, Mammals, Management, Microorganisms, Molluscs, Nematodes, Paleo-ecology, Plants, Pollution studies, Reptiles, River basins, Soil, TAiga/tundra, Terrestrial ecosystems, Vertebrates, Wetlands, Woodlands.
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1998 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Herbivore Optimization by North American Elk written by Kelley Merlet Stewart and published by . This book was released on 2006 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Understanding herbivore optimization has implications for theories underpinning ecosystem processes, management of large herbivores, and the landscapes they inhabit. We designed an experiment to examine interactions related to density dependence of North American elk (Cervus elaphus) and resulting plant responses to herbivory in the Blue Mountains of Oregon, USA, from 1999 to 2001"--Page 1.
Download or read book Restoration of Aquatic Ecosystems written by National Research Council and published by National Academies Press. This book was released on 1992-01-01 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aldo Leopold, father of the "land ethic," once said, "The time has come for science to busy itself with the earth itself. The first step is to reconstruct a sample of what we had to begin with." The concept he expressedâ€"restorationâ€"is defined in this comprehensive new volume that examines the prospects for repairing the damage society has done to the nation's aquatic resources: lakes, rivers and streams, and wetlands. Restoration of Aquatic Ecosystems outlines a national strategy for aquatic restoration, with practical recommendations, and features case studies of aquatic restoration activities around the country. The committee examines: Key concepts and techniques used in restoration. Common factors in successful restoration efforts. Threats to the health of the nation's aquatic ecosystems. Approaches to evaluation before, during, and after a restoration project. The emerging specialties of restoration and landscape ecology.
Download or read book The Management of Natural Coastal Carbon Sinks written by Dan Laffoley and published by IUCN. This book was released on 2009 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Halophytes written by Marius-Nicusor Grigore and published by Springer. This book was released on 2021-05-19 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highlights the potential of biosaline agriculture in a changing environment Covers all important topics related to halophyte biology including biochemistry, genetics and genomics Provides information on potential use of halophytes Each topic is explained in detail and examined from various angles More than 100 contributions by international experts
Download or read book Global Climate Change Impacts in the United States written by U.S. Global Change Research Program and published by Cambridge University Press. This book was released on 2009-08-24 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summarizes the science of climate change and impacts on the United States, for the public and policymakers.
Download or read book Salt Marshes written by Duncan M. FitzGerald and published by Cambridge University Press. This book was released on 2021-04-22 with total page 499 pages. Available in PDF, EPUB and Kindle. Book excerpt: A multidisciplinary review of salt marshes, describing how they function and respond to external pressures such as sea-level rise.
