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Filter Total Items: 3531

The effects of landscape position on plant species density: Evidence of past environmental effects in a coastal wetland The effects of landscape position on plant species density: Evidence of past environmental effects in a coastal wetland

Here we propose that an important cause of variation in species density may be prior environmental conditions that continue to influence current patterns. In this paper we investigated the degree to which species density varies with location within the landscape, independent of contemporaneous environmental conditions. The area studied was a coastal marsh landscape subject to periodic...
Authors
J.B. Grace, G.R. Guntenspergen

Nonindigenous species Nonindigenous species

No abstract available.
Authors
R.A. Orr, G. McClung, R. Peoples, J.D. Williams

Recent advances in life history of Gulf of Mexico sturgeon, Acipenser oxyrinchus desotoi, in the Suwannee River, Florida, USA: A synopsis Recent advances in life history of Gulf of Mexico sturgeon, Acipenser oxyrinchus desotoi, in the Suwannee River, Florida, USA: A synopsis

Gulf sturgeon spawn on portions of three sites in the upper Suwannee River, which may appropriately be described as spawning reefs. The same areas are utilized from year to year. Habitat factors important in spawning site determination include gravel/cobble substrate, the presence of eddy fields, a neutral to slightly alkaline pH, and an empirically observed range in calcium ion content...
Authors
K. J. Sulak, James P. Clugston

The factors controlling species density in herbaceous plant communities: An assessment The factors controlling species density in herbaceous plant communities: An assessment

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...
Authors
J.B. Grace

Induction of triploidy and tetraploidy in Nile tilapia, Oreochromis niloticus (L.) Induction of triploidy and tetraploidy in Nile tilapia, Oreochromis niloticus (L.)

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...
Authors
A.-R.A. El Gamal, K. B. Davis, J.A. Jenkins, Torrans E. Les
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