Publications

Evaluation systems to assess the biotic integrity of plant communities exist for some ecosystems, but not the increasingly rare coastal prairies of Louisiana. A list of plant species occurring in Louisiana's coastal prairie was created and coefficients of conservatism (C) were assigned for each species. A Floristic Quality Index (FQI), which is calculated using the C values provided by a...

In this 3-week laboratory, students investigate the effects of an abiotic or biotic ecological factor on the growth or reproduction of rapid-cycling brassica (Brassica rapa L.: Wisconsin Fast Plants) seedlings in the field. Measurable treatments include light, wind, herbivory, chemical or organic fertilizer, insecticides, and growth regulators (i.e., gibberellic acid spray, auxin paste)...

Several oak species are frequently planted for reforestation projects in the Lower Mississippi Alluvial Valley (LMAV), but the success of these plantings has been variable. The survival and growth of planted seed or seedlings are affected by a variety of factors, including competition, herbivory, site preparation, precipitation, planting stock quality, and planting techniques. We...

Around the world, dams, diversions, and drainage systems reengineer rivers for navigation, farming, and urban development, and this has caused vast changes in the environmental conditions of the flood plains adjacent to these rivers (Middleton, 2002). Even though “flood pulses,” the periodic overflow of these rivers, were once the most important hydrological factor regulating all...

Abstract not supplied at this time

We describe a commercially-available funnel trap for sampling aquatic vertebrates. The traps can be used in heavily vegetated wetlands and can be set in water up to 60 cm deep without concern for drowning the animals. They were especially useful for capturing the aquatic salamanders Siren lacertina and Amphiuma means, which have been difficult to capture with traditional sampling methods...

Abstract not supplied at this time

We estimated adult survival probabilities for the endangered Florida manatee (Trichechus manatus latirostris) in four regional populations using photo-identification data and open-population capture-recapture statistical models. The mean annual adult survival probability over the most recent 10-yr period of available estimates was as follows: Northwest - 0.956 (SE 0.007), Upper St. Johns...

Introduced for sport fishing, as biological controls or other purposes, and as a result of illegal activity, nonnative fishes occupy national park waters where approximately 118 species now compete with native aquatic organisms.

Recruitment patterns in clonal plant populations are predicted to vary with seed dispersal capability and disturbance regime, such that species with small, widely dispersed seeds will become increasingly dominated by vegetative recruitment on disturbed areas following early colonization. Subsequent mortality due to competitive or stochastic effects is then predicted to cause a gradual...

1. Dwarf stands of the mangrove Rhizophora mangle L. are extensive in the Caribbean. We fertilized dwarf trees in Almirante Bay, Bocas del Toro Province, north-eastern Panama with nitrogen (N) and phosphorus (P) to determine (1) if growth limitations are due to nutrient deficiency; and (2) what morphological and/or physiological factors underlie nutrient limitations to growth. 2. Shoot...

No abstract available.