Abstract
The cycling and sequestration of carbon are important ecosystem functions of estuarine wetlands that may be affected by climate change. We conducted experiments across a latitudinal and climate gradient of tidal marshes in the northeast Pacific to evaluate the effects of climate- and vegetation-related factors on litter decomposition. We manipulated tidal exposure and litter type in experimental mesocosms at two sites and used variation across marsh landscapes at seven sites to test for relationships between decomposition and marsh elevation, soil temperature, vegetation composition, litter quality, and sediment organic content. A greater than tenfold increase in manipulated tidal inundation resulted in small increases in decomposition of roots and rhizomes of two species, but no significant change in decay rates of shoots of three other species. In contrast, across the latitudinal gradient, decomposition rates of Salicornia pacifica litter were greater in high marsh than in low marsh. Rates were not correlated with sediment temperature or organic content, but were associated with plant assemblage structure including above-ground cover, species composition, and species richness. Decomposition rates also varied by litter type; at two sites in the Pacific Northwest, the grasses Deschampsia cespitosa and Distichlis spicata decomposed more slowly than the forb S. pacifica. Our data suggest that elevation gradients and vegetation structure in tidal marshes both affect rates of litter decay, potentially leading to complex spatial patterns in sediment carbon dynamics. Climate change may thus have direct effects on rates of decomposition through increased inundation from sea-level rise and indirect effects through changing plant community composition.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1296-1310 |
| Number of pages | 15 |
| Journal | Ecosystems |
| Volume | 20 |
| Issue number | 7 |
| DOIs | |
| State | Published - Nov 1 2017 |
Bibliographical note
Funding Information:Funding for this study was provided by the U.S. Department of the Interior Southwest and Northwest Climate Science Centers, the U.S. Geological Survey DOI on the Landscape Program, the Ecosystems and Climate and Land-use Research and Development programs of the U.S. Geological Survey, and Oregon State University. We thank Tristan Edgarian, Craig Cornu, Jenni Schmitt, Patrick Brennand, Yareli Sanchez, Len-nah Shakeri, Laura Hollander, Ari Goodman, Sierra Blakely, Chase Freeman, Jimmie Lambert, Dave Nelson, Mee-ya Monnin, and Jordan Rosencranz for their valuable assistance with this project. The U.S. Fish and Wildlife Service, NOAA’s South Slough National Estuarine Research Reserve, U.S. Navy, California State Parks, and California Department of Fish and Wildlife kindly permitted access to the research sites. We thank J. Jones and two anonymous reviewers for comments that improved the manuscript. Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. government. The findings and conclusions in this article are those of the authors and do not necessarily represent the views of the SWCSC or NWCSC. This manuscript is submitted for publication with the understanding that the U.S. Government is authorized to reproduce and distribute reprints for governmental purposes.
Funding Information:
Funding for this study was provided by the U.S. Department of the Interior Southwest and Northwest Climate Science Centers, the U.S. Geological Survey DOI on the Landscape Program, the Ecosystems and Climate and Land-use Research and Development programs of the U.S. Geological Survey, and Oregon State University. We thank Tristan Edgarian, Craig Cornu, Jenni Schmitt, Patrick Brennand, Yareli Sanchez, Lennah Shakeri, Laura Hollander, Ari Goodman, Sierra Blakely, Chase Freeman, Jimmie Lambert, Dave Nelson, Mee-ya Monnin, and Jordan Rosencranz for their valuable assistance with this project. The U.S. Fish and Wildlife Service, NOAA?s South Slough National Estuarine Research Reserve, U.S. Navy, California State Parks, and California Department of Fish and Wildlife kindly permitted access to the research sites. We thank J. Jones and two anonymous reviewers for comments that improved the manuscript. Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. government. The findings and conclusions in this article are those of the authors and do not necessarily represent the views of the SWCSC or NWCSC. This manuscript is submitted for publication with the understanding that the U.S. Government is authorized to reproduce and distribute reprints for governmental purposes. Author contributions C.J., G.G., J.T., and K.T. designed the study; C.J., K.B., and B.D. conducted field work; C.J. analyzed the data; C.J. wrote the paper, K.B. produced Fig. 1, and all authors helped revise the paper. Janousek, C.N., Buffington, K.J., Guntenspergen, G.R., Thorne, K.M., Dugger, B.D., and Takekawa, J.Y., 2017, Decomposition of plant litter in Pacific coast tidal marshes, 2014?2015: U.S. Geological Survey data release, http://doi.org/10.5066/F70P0X6C.
Publisher Copyright:
© 2017, Springer Science+Business Media New York.
Keywords
- carbon cycling
- plant composition
- sea-level rise
- sediment temperature
- species richness
- tidal inundation
