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Explore WARC's science publications.

Filter Total Items: 3374

Long-term growth trends of baldcypress (Taxodium distichum (L.) rich.) at Caddo Lake, Texas

Caddo Lake, situated on the border of northeast Texas and northwest Louisiana, USA is a medium-sized lake dominated by stands of baldcypress (Taxodiwn distichum). A study of tree growth was initiated at Caddo Lake to address concerns about the health of the baldcypress ecosystem. The lake has been subjected to several dramatic water-level changes over the past 200 years, including water-level stab
Authors
B. D. Keeland, P.J. Young

Vertebrate herbivory in managed coastal wetlands: A manipulative experiment

Structural marsh management and nutria herbivory are both believed to strongly influence plant production in the brackish, deltaic marshes of coastal Louisiana, USA. Previous studies have tested the effects of structural management on aboveground biomass after implementing management, but very few studies have collected data before and after management. Thus, to test the effects of structural mars
Authors
L.A. Johnson, A.L. Foote

The effects of herbivory on neighbor interactions along a coastal marsh gradient

Many current theories of community function are based on the assumption that disturbances such as herbivory act to reduce the importance of neighbor interactions among plants. In this study, we examined the effects of herbivory (primarily by nutria, Myocastor coypus) on neighbor interactions between three dominant grasses in three coastal marsh communities, fresh, oligohaline, and mesohaline. The
Authors
K.L. Taylor, J.B. Grace, B.D. Marx

Conserving coastal wetlands despite sea-level rise

Abstract not supplied at this time
Authors
W.K. Nuttle, T. J. Smith

Temperature effects on stocks and stability of a phytoplankton-zooplankton model and the dependence on light and nutrients

A model of a closed phytoplankton—zooplankton ecosystem was analyzed for effects of temperature on stocks and stability and the dependence of these effects on light and total nutrient concentration of the system. An analysis of the steady state equations showed that the effect of temperature on zooplankton and POM biomass was levelled when primary production is nutrient limited. Temperature increa
Authors
J. Norberg, D.L. DeAngelis

A rop net and removable walkway used to quantitatively sample fishes over wetland surfaces in the dwarf mangrove of the Southern Everglades

We describe a 9 m2 drop net and removable walkways designed to quantify densities of small fishes in wetland habitats with low to moderate vegetation density. The method permits the collection of small, quantitative, discrete samples in ecologically sensitive areas by combining rapid net deployment from fixed sites with the carefully contained use of the fish toxicant rotenone. This method require
Authors
J.J. Lorenz, C.C. McIvor, G. V. N. Powell, P. C. Frederick

Population viability analysis of the Florida manatee (Trichechus manatus latirostris), 1976-1991

Recent development of age-determination techniques for Florida manatees (Trichechus manatus latirostris) has permitted derivation of age-specific data on reproduction and survival of a sample of 1212 carcasses obtained throughout Florida from 1976–1991. Population viability analysis using these data projects a slightly negative growth rate (−0.003) and an unacceptably low probability of persistenc
Authors
M. Marmontel, S.R. Humphrey, T. J. O'Shea

Source-sink dynamics and the coexistence of species on a single resource

We investigate the potential for coexistence of species that compete for a shared resource when the resource occurs in both a source area acting as a refuge and a sink area where it is used by the competing species. Our model shows that the mixing rate between the source and sink resource populations has a dramatic influence on the outcome of competition. When there is a strict sink–source depende
Authors
M. Loreau, D.L. DeAngelis

A simulation study of the spatiotemporal dynamics of the Unionid mussels

Abstract not supplied at this time
Authors
Hooi-Ling Lee, D.L. DeAngelis

Facing the challenges of invasive alien species in North America

Abstract not supplied at this time
Authors
I.E. Effort, C. Macias Garcia, J.D. Williams

Effects of habitat suitability on the survival of relocated freshwater mussels

Freshwater mussels are often relocated from existing beds for both conservation and management reasons. In this study, we empirically tested whether the habitat type at the destination site was important in predicting the success of mussel relocation. In 1993, four species of freshwater mussels were relocated in the Apalachicola River in Florida, into three distinct habitat types: stable sand, lim
Authors
Hannah M. Hamilton, Jayne Brim-Box, Robert M. Dorazio