Tidal Flat Ecosystem Ecology
Macroalgal mats and geomorphic features create structural heterogeneity in otherwise flat, homogeneous environments. My dissertation and ongoing research examine relationships between hydrologic flow, geomorphology, macroalgal mats, and microphytobenthos in the Virginia Coast Reserve LTER. The non-native macroalga Agarophyton vermiculophyllum (previously Gracilaria vermiculophylla) is dominant, and the focal species for research.
Macroalgal Canopy Effects on Microphytobenthos
I quantified effects of macroalgal mat canopies on microphytobenthos growing beneath on tidal flats. Using a whole-ecosystem experiment, a field survey, and meta-analysis, I found macroalgal mats dominated by Agarophyton had no consistent effect on microphytobenthos biomass.
Besterman, A.F. & Pace, M.L. 2018. Do macroalgal canopies impact microphytobenthos on mudflats? Evidence from a meta-analysis, comparative survey, and large-scale manipulation. Estuaries and Coasts 41:2304-2316. https://doi.org/10.1007/s12237-018-0418-3 |
Macroalgal Distributions Across a Seascape
Using a LiDAR-derived digital elevation model (DEM), modeled hydrologic flow variables (water residence time, wind fetch), and sediment particle size distributions, I modeled species-distribution relationships for macroalgal communities dominated by Agarophyton. Using the DEM I developed a novel topographic variable for mudflats, that integrated hydrologic and geomorphic characteristics relevant for macroalgal survival and growth. I found the "hummockiness" of a mudflat, in interaction with the water residence time for the local embayment, determined the abundance of macroalgae across a > 900 km2 coastal seascape.
Besterman AF, K.J. McGlathery, M.A. Reidenbach, P.L. Wiberg, M.L. Pace. Predicting benthic macroalgal abundance in shallow coastal lagoons from geomorphology and hydrologic flow patterns. Limnology and Oceanography: Early View. https://doi.org/10.1002/lno.11592 |
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