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Abstract Understanding microbial roles in ecosystem function requires integrating microscopic processes into food webs. The carnivorous pitcher plant,Sarracenia purpurea, offers a tractable study system where diverse food webs of macroinvertebrates and microbes facilitate digestion of captured insect prey, releasing nutrients supporting the food web and host plant. However, how interactions between these macroinvertebrate and microbial communities contribute to ecosystem functions remains unclear. We examined the role of the pitcher plant mosquito,Wyeomyia smithii, in top‐down control of the composition and function of pitcher plant microbial communities. Mosquito larval abundance was enriched or depleted across a natural population ofS. purpureapitchers over a 74‐day field experiment. Bacterial community composition and microbial community function were characterized by 16S rRNA amplicon sequencing and profiling of carbon substrate use, bulk metabolic rate, hydrolytic enzyme activity, and macronutrient pools. Bacterial communities changed from pitcher opening to maturation, but larvae exerted minor effects on high‐level taxonomic composition. Higher larval abundance was associated with lower diversity communities with distinct functions and elevated nitrogen availability. Treatment‐independent clustering also supported roles for larvae in curating pitcher microbial communities through shifts in community diversity and function. These results demonstrate top‐down control of microbial functions in an aquatic microecosystem.
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Benthic and Epibenthic Invertebrate Assemblages Associated with Estuarine Submerged Aquatic Vegetation Differ Between Native and Invasive Plants
Estuarine submerged aquatic vegetation (SAV) provides vital habitat for macroinvertebrate communities that support diverse food webs and subsequent ecosystem services. Invasive SAV, however, has the potential to alter estuarine food webs through competition with native SAV, resulting in different associated biological communities. In the Mobile-Tensaw Delta (Alabama, USA), the invasive Eurasian milfoil, Myriophyllum spicatum, is fast becoming the dominant SAV, out-competing native SAV such as wild celery, Vallisneria americana. This study investigated the above- and belowground macroinvertebrate assemblages associated with these SAV habitats. We found significantly different assemblages between the SAV, with V. americana supporting more even and diverse epifaunal assemblages, and M. spicatum supporting greater total abundances of macroinvertebrates. Gammarid amphipods were more than 11 times more abundant in M. spicatum, while Polychaete species were threefold more abundant in V. americana. Our results suggest that V. americana may support a more diverse and even community compared to M. spicatum. If so, the continued decline in coverage of native V. americana and invasion of M. spicatum across the Mobile-Tensaw Delta could have system-wide ecological consequences.
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- Award ID(s):
- 2150347
- PAR ID:
- 10574306
- Publisher / Repository:
- Gulf and Caribbean Research
- Date Published:
- Journal Name:
- Gulf and Caribbean Research
- Volume:
- 35
- ISSN:
- 2572-1410
- Page Range / eLocation ID:
- SC25 to SC30
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Russel, JA (Ed.)Understanding microbial roles in ecosystem function requires integrating microscopic processes into food webs. The carnivorous pitcher plant, Sarracenia purpurea, offers a tractable study system where diverse food webs of macroinvertebrates and microbes facilitate digestion of captured insect prey, releasing nutrients supporting the food web and host plant. However, how interactions between these macroinvertebrate and microbial communities contribute to ecosystem functions remains unclear. We examined the role of the pitcher plant mosquito, Wyeomyia smithii, in top-down control of the composition and function of pitcher plant microbial communities. Mosquito larval abundance was enriched or depleted across a natural population of S. purpurea pitchers over a 74-day field experiment. Bacterial community composition and microbial community function were characterized by 16S rRNA amplicon sequencing and profiling of carbon substrate use, bulk metabolic rate, hydrolytic enzyme activity, and macronutrient pools. Bacterial communities changed from pitcher opening to maturation, but larvae exerted minor effects on high-level taxonomic composition. Higher larval abundance was associated with lower diversity communities with distinct functions and elevated nitrogen availability. Treatment-independent clustering also supported roles for larvae in curating pitcher microbial communities through shifts in community diversity and function. These results demonstrate top-down control of microbial functions in an aquatic microecosystem.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.18785/gcr.3501.18
