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The advancement of species poleward, due to global warming, has recently been documented worldwide. In Louisiana, Avicennia germinans (black mangrove) is moving northward into Spartina alterniflora salt marshes. Mangroves were historically restricted to southernmost islands and beaches by winter freezes; however, recently a noticeable expansion has occurred. The influence that mangroves have on ecosystem...
Secondarily treated municipal effluent from Breaux Bridge, Louisiana has been discharged into the Cypriere Perdue forested wetland since the early 1950s. Approximately one million gallons per day (3,785 m−3 day−1) are discharged into the 1470 ha wetland, with average total nitrogen and phosphorus loading rates of 1.15 g N m−2 yr−1 and 0.31 g P m−2 yr−1, respectively. Vegetation and water quality of...
Hurricanes have shaped the structure of mangrove forests in the Everglades via wind damage, storm surges and sediment deposition. Immediate effects include changes to stem size-frequency distributions and to species relative abundance and density. Long-term impacts to mangroves are poorly understood at present. We examine impacts of Hurricane Wilma on mangroves and compare the results to findings...
Dryland rivers are characterized by high spatio-temporal variability in water resources, with alternating wet and dry reaches and fluctuating stream flow rates. To investigate response to this dynamic, riparian plant communities from perennial, temporally intermittent, and ephemeral-flow reaches of the Hassayampa River and an ephemeral tributary (southwestern USA) were characterized over a three year...
Vegetation structure and soil properties were measured on a sandbar, a three year old sandbar emergent marsh (SEM), and five mature Spartina alterniflora Loisel marshes located near the mouth of the Altamaha River (Georgia, USA) to determine how quickly tidal marsh vegetation and soils develop during primary succession. Those data were compared to published data collected from young (10–16 yr old)...
The floating mat fens of the Tanana Flats in interior Alaska are productive wetlands near the urban center of Fairbanks. Airboat traffic has created a network of trails through the floating vegetation mats. We established protected areas along established trails, which allowed for measurement of plant community resistance to airboat traffic and resilience following cessation of traffic. The fen plant...
Understanding the consequences of hurricanes on the food resources available to neotropicalnearctic migrant songbirds may provide important insight into the effects of hurricanes on migratory populations. During autumn migration 2006 we investigated the foraging ecology of two species of insectivorous migrants, Blue-gray Gnatcatcher (Polioptila caerulea) and Yellow Warbler (Dendroica petechia), and...
Hurricanes can damage trees in forested wetlands, and the potential for mortality related to these storms exists due to the effects of tree damage over time. In August 1992, Hurricane Andrew passed through the forested wetlands of southern Louisiana with winds in excess of 225 kph. Although more than 78% of the basal area was destroyed in some areas, most trees greater than 2.5 cm dbh were alive and...
Most wetland maps must be updated for much of North America. High-resolution satellite images and LiDAR-based elevation data have been developed in recent years, and these may prove useful in wetland mapping. We compared the accuracy of the Wisconsin Wetland Inventory maps (WWI) to maps derived from IKONOS high resolution satellite data and LiDAR data for a 63.4 km2 study area in north-central Wisconsin...
Hurricane Katrina pushed mixed Taxodium distichum forests toward a dominance of Taxodium distichum (baldcypress) and Nyssa aquatica (water tupelo) because these species had lower levels of susceptibility to wind damage than other woody species. This study documents the volume of dead versus live material of woody trees and shrubs of T. distichum swamps following Hurricane Katrina along the Gulf Coast...
We investigated variation in species resistance to hurricane winds and effects of Hurricane Rita on long-term forest dynamics using three 4-ha permanent plots in the Big Thicket of east Texas. Woody stems > 4.5 cm DBH that were severely damaged, uprooted, or snapped constituted 5% of stems at the dry upland site, 22% at the river floodplain site, and 31% at the mesic site. This variation corresponded...
In estuarine systems, informed water resource management decisions rely, in part, on evaluating how changes in freshwater inflow and salinity affect a selected management target (i.e., habitat or organismal changes). This study examined the distribution of Spartina alterniflora and S. cynosuriodes species along the Altamaha River estuary in Georgia in association with an extensive drought, during...
Little is known about the effectiveness of mangroves in suppressing water level heights during landfall of tropical storms and hurricanes. Recent hurricane strikes along the Gulf Coast of the United States have impacted wetland integrity in some areas and hastened the need to understand how and to what degree coastal forested wetlands confer protection by reducing the height of peak water level. In...
Tropical weather disturbances are a major influence on coastal wetlands in North America. However, studies of their impact on biotic communities are rare. The abundance and species composition of amphibians and reptiles were investigated within levee, herbaceous marsh, and forested swamp habitats in southeastern Louisiana from 2002 to 2004 and again in 2005 to 2006. During the course of this study,...
We added nitrogen (N), phosphorus (P), and N+P to a Zizaniopsis miliacea (Giant Cutgrass) dominated tidal freshwater marsh in Georgia USA to investigate nutrient limitation of tidal freshwater marsh primary production and invertebrate densities. After two years, aboveground biomass was significantly greater in the plots receiving N (2130 g m−2), and N+P (2066 g m−2) than in the control (886 g m−2)...
Hemerocallis esculenta suffered frost damage during a night of remarkably low temperatures at Sarobetsu Mire, northern Japan, on 5 June 2002. A numerical model simulation was conducted to evaluate how groundwater conditions affected the nocturnal air temperature at the mire. The numerical model developed in this study reproduced the nighttime cooling process of the air temperature profile at high...
To evaluate the effects of saltwater intrusion and nutrient enrichment on wetland microbial communities, we measured changes in sediment microbial structure and function in response to increased salinity and nutrients. Sediments were collected from a cypress-tupelo swamp near Lake Pontchartrain, Louisiana, USA, and maintained in microcosms treated with elevated salinity, nitrogen (N), or phosphorus...
Two long-term submerged Eutric Gleysols (GLe) and two short-term flooded Eutric Fluvisols (FLe) with high organic carbon contents (Corg between 5.1 and 12.9%) were selected to characterize soil microbial communities at the Elbe River (Germany). Measurements included dehydrogenase activity (DHA), soil microbial carbon (Cmic), soil basal respiration (BR), metabolic quotient (qCO2), Cmic/Corg ratio,...
The Everglades ecosystem contains the largest contiguous tract of mangrove forest outside the tropics that were also coincidentally intersected by a major Category 5 hurricane. Airborne videography was flown to capture the landscape pattern and process of forest damage in relation to storm trajectory and circulation. Two aerial video transects, representing different topographic positions, were used...
Hydrologic budgets for depressional wetlands require estimates of runoff from watersheds. In the Southern High Plains, where there is little elevation relief, ground surveys provide accurate watershed estimates but are time-consuming and costly. Estimates can be derived at lower cost from DEMs (Digital Elevation Models) and topographical maps, but data resolution and interpretation introduces errors...
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