Spatial and temporal pattern in seagrass community composition and productivity in south Florida
Fourqurean, J.W.; Willsie, A.; Rose, C.D.; Rutten, L.M. (2001). Spatial and temporal pattern in seagrass community composition and productivity in south Florida. Mar. Biol. (Berl.) 138(2): 341-354. http://dx.doi.org/10.1007/s002270000448
In: Marine Biology: International Journal on Life in Oceans and Coastal Waters. Springer: Heidelberg; Berlin. ISSN 0025-3162; e-ISSN 1432-1793, more
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| Authors | | Top |
- Fourqurean, J.W.
- Willsie, A.
- Rose, C.D.
- Rutten, L.M.
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| Abstract |
We document the distribution and abundance of seagrasses, as well as the intra-annual temporal patterns in the abundance of seagrasses and the productivity of the nearshore dominant seagrass (Thalassia testudinum) in the south Florida region. At least one species of seagrass was present at 80.8% of 874 randomly chosen mapping sites, delimiting 12,800?km2 of seagrass beds in the 17,000-km2 survey area. Halophila decipiens had the greatest range in the study area; it was found to occur over 7,500?km2. The range of T. testudinum was almost as extensive (6,400?km2), followed by Syringodium filiforme (4,400?km2), Halodule wrightii (3,000?km2) and Halophila engelmanni (50?km2?). The seasonal maxima of standing crop was about 32% higher than the yearly mean. The productivity of T. testudinum was both temporally and spatially variable. Yearly mean areal productivity averaged 0.70 g?m-2day-1, with a range of 0.05–3.29?g?m-2?day-1. Specific productivity ranged between 3.2 and 34.2 mg?g-1?day-1, with a mean of 18.3?mg?g-1?day-1. Annual peaks in specific productivity occurred in August, and minima in February. Integrating the standing crop for the study area gives an estimate of 1.4?×?1011?g T.?testudinum and 3.6?×?1010?g S. filiforme, which translate to a yearly production of 9.4?×?1011?g T.?testudinum leaves and 2.4?×?1011?g S. filiforme leaves. We assessed the efficacy of rapid visual surveys for estimating abundance of seagrasses in south Florida by comparing these results to measures of leaf biomass for T. testudinum and S. filiforme. Our rapid visual surveys proved useful for quantifying seagrass abundance, and the data presented in this paper serve as a benchmark against which future change in the system can be quantified. |
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