Publications

This paper evaluates both the ideas and empirical evidence pertaining to the control of species density in herbaceous plant communities. While most theoretical discussions of species density have emphasized the importance of habitat productivity and disturbance regimes, many other factors (e.g. species pools, plant litter accumulation, plant morphology) have been proposed to be important...

No abstract available.

Lake Chicot, in south central Louisiana, USA, was created in 1943 by the impoundment of Chicot Bayou. Extensive establishment of woody seedlings occurred in the lake during a 1.5 year period, including the growing seasons of both 1986 and 1987, when the reservoir was drained for repair work on the dam. Study plots were established in September 1986 to document woody vegetation...

Induction of triploidy and tetraploidy in Nile tilapia, Oreochromis niloticus, was investigated by heat shock, cold shock, hydrostatic pressure, and/or chemicals (cytochalasin A, B, and D). Additionally, efficacy of combined protocols was determined. Heat shock 10 min after fertilization induced triploidy when incubation temperature was 24 C but not when incubation temperature was 31 C...

In the United States lead is an ubiquitous environmental pollutant that is a serious human health hazard, especially for women of childbearing age, developing fetuses, and young children. Information concerning the uptake and distribution of lead to maternal and fetal tissues during pregnancy is poorly documented. A study was designed using domestic swine and lead isotope enrichment...

Aircraft L-band VV-, HH-, and VH-polarizations were examined as tools for monitoring burn recovery in a coastal marsh. Significant relationships were observed between time-since-burn (difference between burn and image collection dates; 550-900 days after burn) and returns related to all polarizations. As marsh burn recovery progressed, VV returns decreased while HH and VH returns...

Water resources data for the 1999 water year for South Carolina consist of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; and ground-water levels. This report contains discharge records for 118 gaging stations; stage-only records for 38 gaging stations; stage and contents for 17 lakes and reservoirs; water quality for 42 gaging...

Water-resources data for the 1998 water year for Texas are presented in four volumes, and consist of records of stage, discharge, and water quality of streams and canals; stage, contents, and water-quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 1 contains records for water discharge at 112 gaging stations; stage only at 5 gaging stations...

Variation of electrochemical oxidation-reduction (redox) potential was examined in surface salt march sediments under conditions of flooding and tidal simulation in mesocosms and field sites. Time series were generated of redox potential measured in sediment profiles at 2-10 cm depth using combination Pt-Ag/AgCl (ORP) electrodes. Redox potential data were acquired at rapid rates (1-55...

No abstract available.

This report presents data for samples of periphyton and water collected in 1995 and 1996 from Water Conservation Areas, the Big Cypress National Preserve, and the Everglades National Park in south Florida. Periphyton samples were analyzed for concentrations of total mercury, methylmercury, nitrogen, phosphorus, organic carbon, and inorganic carbon . Water-column samples collected on the...

In 1996, seven cores were recovered in western Collier County, southwestern Florida, to acquire subsurface geologic and hydrologic data to support ground-water modeling efforts. This report presents the lithostratigraphy, X-ray diffraction analyses, petrography, biostratigraphy, and strontium-isotope stratigraphy of these cores. The oldest unit encountered in the study cores is an...