气候变化领域集成服务门户(CCPortal): Sea-level rise and the emergence of a keystone grazer alter the geomorphic evolution and ecology of southeast US salt marshes

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DOI	10.1073/pnas.1917869117
	Sea-level rise and the emergence of a keystone grazer alter the geomorphic evolution and ecology of southeast US salt marshes
	Crotty S.M.; Ortals C.; Pettengill T.M.; Shi L.; Olabarrieta M.; Joyce M.A.; Altieri A.H.; Morrison E.; Bianchi T.S.; Craft C.; Bertness M.D.; Angelini C.
发表日期	2020
ISSN	0027-8424
起始页码	17891
结束页码	17902
卷号	117 期号:30
英文摘要	Keystone species have large ecological effects relative to their abundance and have been identified in many ecosystems. However, global change is pervasively altering environmental conditions, potentially elevating new species to keystone roles. Here, we reveal that a historically innocuous grazer—the marsh crab Sesarma reticulatum—is rapidly reshaping the geomorphic evolution and ecological organization of southeastern US salt marshes now burdened by rising sea levels. Our analyses indicate that sea-level rise in recent decades has widely outpaced marsh vertical accretion, increasing tidal submergence of marsh surfaces, particularly where creeks exhibit morphologies that are unable to efficiently drain adjacent marsh platforms. In these increasingly submerged areas, cordgrass decreases belowground root:rhizome ratios, causing substrate hardness to decrease to within the optimal range for Sesarma burrowing. Together, these bio-physical changes provoke Sesarma to aggregate in high-density grazing and burrowing fronts at the heads of tidal creeks (hereafter, creekheads). Aerial-image analyses reveal that resulting “Sesarma-grazed” creekheads increased in prevalence from 10 ± 2% to 29 ± 5% over the past <25 y and, by tripling creek-incision rates relative to nongrazed creekheads, have increased marsh-landscape drainage density by 8 to 35% across the region. Field experiments further demonstrate that Sesarma-grazed creekheads, through their removal of vegetation that otherwise obstructs predator access, enhance the vulnerability of macrobenthic invertebrates to predation and strongly reduce secondary production across adjacent marsh platforms. Thus, sea-level rise is creating conditions within which Sesarma functions as a keystone species that is driving dynamic, landscape-scale changes in saltmarsh geomorphic evolution, spatial organization, and species interactions. © 2020 National Academy of Sciences. All rights reserved.
英文关键词	Biodiversity; Bioturbation; Ecosystem engineer; Herbivory; Morphodynamics
语种	英语
scopus关键词	Article; climate change; coastal plain; community structure; controlled study; field experiment; geomorphology; grassland; grazer; grazing; keystone species; land drainage; macrobenthos; nonhuman; organismal interaction; predator prey interaction; priority journal; salt marsh; sea level rise; secondary production (biomass); Sesarma reticulatum; United States
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160870
作者单位	Crotty, S.M., Department of Environmental Engineering Sciences, Engineering School of Sustainable Infrastructure and Environment, University of Florida, Gainesville, FL 32611, United States, School of the Environment, Yale University, New Haven, CT 06511, United States; Ortals, C., Department of Coastal Engineering, Engineering School of Sustainable Infrastructure and Environment, University of Florida, Gainesville, FL 32611, United States; Pettengill, T.M., Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912, United States; Shi, L., Department of Coastal Engineering, Engineering School of Sustainable Infrastructure and Environment, University of Florida, Gainesville, FL 32611, United States; Olabarrieta, M., Department of Coastal Engineering, Engineering School of Sustainable Infrastructure and Environment, University of Florida, Gainesville, FL 32611, United States; Joyce, M.A., Department of Biosciences, Swansea University, Singleton Park, Swansea, SA28PP, Unite...
推荐引用方式 GB/T 7714	Crotty S.M.,Ortals C.,Pettengill T.M.,et al. Sea-level rise and the emergence of a keystone grazer alter the geomorphic evolution and ecology of southeast US salt marshes[J],2020,117(30).
APA	Crotty S.M..,Ortals C..,Pettengill T.M..,Shi L..,Olabarrieta M..,...&Angelini C..(2020).Sea-level rise and the emergence of a keystone grazer alter the geomorphic evolution and ecology of southeast US salt marshes.Proceedings of the National Academy of Sciences of the United States of America,117(30).
MLA	Crotty S.M.,et al."Sea-level rise and the emergence of a keystone grazer alter the geomorphic evolution and ecology of southeast US salt marshes".Proceedings of the National Academy of Sciences of the United States of America 117.30(2020).