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Coral reefs experience numerous natural and anthropogenic environmental gradients that alter biophysical conditions and affect biodiversity. While many studies have focused on drivers of reef biodiversity using traditional diversity metrics (e.g., species richness, diversity, evenness), less is known about how environmental variability may influence functional diversity. In this study, we tested the impact of submarine groundwater discharge (SGD) on taxonomic and functional diversity metrics in Mo‘orea, French Polynesia. SGD is the expulsion of terrestrial fresh or recirculated seawater into marine environments and is associated with reduced temperatures, pH, and salinity and elevated nutrient levels. Using a regression approach along the SGD gradient, we found that taxon and functional-entity richness displayed unimodal relationships to SGD parameters, primarily nitrate + nitrite and phosphate variability, with peak richness at moderate SGD for stony coral and the full benthic community. Macroalgae showed this unimodal pattern for functional-entity but not taxonomic richness. Functional community composition (presence and abundance of functional entities) increased along the gradient, while taxonomic composition showed a nonlinear relationship to SGD-related parameters. SGD is a common feature of many coastal ecosystems globally and therefore may be more important to structuring benthic functional diversity than previously thought. Further, studying community shifts through a functional-trait lens may provide important insights into the roles of community functions on ecosystem processes and stability, leading to improved management strategies.
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The Dynamics of Soil Mesofauna Communities in a Tropical Urban Coastal Wetland: Responses to Spatiotemporal Fluctuations in Phreatic Level and Salinity
Coastal wetlands, vital for ecological diversity, have been significantly altered by anthropogenic activities, particularly in the Caribbean. These changes have created a complex mosaic of habitats and physicochemical conditions, further stressed by climate variability and sea-level rise. This study, conducted in Las Cucharillas Natural Reserve, a tropical urban coastal wetland in Puerto Rico, aimed to determine the effects of spatiotemporal variations in phreatic levels and salinity on soil mesofauna assemblages, crucial bio-indicators of environmental change. In 2020 and 2021, soil samples were collected from five diverse habitat types during different hydroperiods. Each sample was taken under four randomly selected plant types and processed using lighted Tullgren–Berlese extractors. Phreatic level and salinity were also measured. A total of 43 families were quantified, underscoring distinct habitat differences, similarities, and overall ecosystem diversity. Moderate correlations between phreatic levels, salinity, and mesofauna richness and abundance were determined. Peak richness and abundance were quantified at shallow (−0.03 to −0.07 m) and slightly moderate (−0.12 to −0.17 m) phreatic levels where oligohaline salinity (>0.5 to 5.0 ppt) prevails. The study highlights the adaptability of mesofauna to environmental shifts and their potential as biosensors for effective coastal wetland management amid climatic and anthropogenic pressures.
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- Award ID(s):
- 1736093
- PAR ID:
- 10497656
- Publisher / Repository:
- MDPI
- Date Published:
- Journal Name:
- Arthropoda
- Volume:
- 2
- Issue:
- 1
- ISSN:
- 2813-3323
- Page Range / eLocation ID:
- 1 to 27
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/arthropoda2010001
