Virginia Institute of Marine Science
Human-driven habitat fragmentation is cited as one of the most pressing threats facing many coastal ecosystems today. Many experiments have explored the consequences of fragmentation on fauna in one foundational habitat, seagrass beds, but have either surveyed along a gradient of existing patchiness, used artificial materials to mimic a natural bed, or sampled over short timescales. Here, we describe faunal responses to constructed fragmented landscapes varying from 4-400 m(2) in two transplant garden experiments incorporating live eelgrass (Zostera marina L.). In experiments replicated within two subestuaries of the Chesapeake Bay, USA across multiple seasons and non-consecutive years, we comprehensively censused mesopredators and epifaunal communities using complementary quantitative methods. We found that community properties, including abundance, species richness, Simpson and functional diversity, and composition were generally unaffected by the number of patches and the size of the landscape, or the intensity of sampling. Additionally, an index of competition based on species co-occurrences revealed no trends with increasing patch size, contrary to theoretical predictions. We extend conclusions concerning the invariance of animal communities to habitat fragmentation from small-scale observational surveys and artificial experiments to experiments conducted with actual living plants and at more realistic scales. Our findings are likely a consequence of the rapid life histories and high mobility of the organisms common to eelgrass beds, and have implications for both conservation and restoration, suggesting that even small patches can rapidly promote abundant and diverse faunal communities.
ZOSTERA-MARINA L; SUBMERGED AQUATIC VEGETATION; RAOS QUADRATIC ENTROPY; LOWER CHESAPEAKE BAY; GULF-OF-MEXICO; HABITAT FRAGMENTATION; SPECIES COOCCURRENCE; PATCH SIZE; DIVERSITY; BEDS
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Funding was provided by the grants from the Virginia Recreational Fishing License Fund, as well as private grants from the Allied-Signal Foundation and the Keith Campbell Foundation for the Environment.
Sasha Tozzi, Walker O. Smith. Contrasting Photo-physiological Responses of the Haptophyte Phaeocystis Antarctica and the Diatom Pseudonitzschia sp. in the Ross Sea (Antarctica). AIMS Geosciences, 2017, 3(2): 142-162. doi: 10.3934/geosci.2017.2.142