Responses of Spartina alterniflora to Multiple Stressors: Changing Precipitation Patterns, Accelerated Sea Level Rise, and Nutrient Enrichment
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- 作者：Alana Hanson ; Roxanne Johnson ; Cathleen Wigand ; Autumn Oczkowski…
- 刊名：Estuaries and Coasts
- 出版年：2016
- 出版时间：September 2016
- 年：2016
- 卷：39
- 期：5
- 页码：1376-1385
- 全文大小：9,070 KB
- 刊物类别：Earth and Environmental Science
- 刊物主题：Environment
Environment
Ecology
Geosciences
Environmental Management
Nature Conservation - 出版者：Springer New York
- ISSN：1559-2731
- 卷排序：39
文摘
Coastal wetlands, well recognized for their ecosystem services, have faced many threats throughout the USA and elsewhere. While managers require good information on the net impact of these combined stressors on wetlands, little such information exists. We conducted a 4-month mesocosm study to analyze the multiple stressor effects of precipitation changes, sea level rise, and eutrophication on the salt marsh plant Spartina alterniflora. Pots containing plants in an organic soil matrix were positioned in tanks and received Narragansett Bay (RI, USA) water. The study simulated three precipitation levels (ambient daily rain, biweekly storm, and drought), three levels of tidal inundations (high (15 cm below mean high water (MHW)), mean (MHW), and low (15 cm above MHW)), and two nutrient enrichment levels (unenriched and nutrient-enriched bay water). Our results demonstrate that storm and drought stressors led to significantly less above- and belowground biomass than those in ambient rain conditions. Plants that were flooded at high inundation had less belowground biomass, fine roots, and shoots. Nutrients had no detectable effect on aboveground biomass, but the enriched pots had higher stem counts and more fine roots than unenriched pots, in addition to greater CO2 emission rates; however, the unenriched pots had significantly more coarse roots and rhizomes, which help to build peat in organogenic marshes. These results suggest that multiple stressors of altered precipitation, sea level rise, and nutrient enrichment would lead to reduced marsh sustainability.KeywordsSalt marshSpartina alternifloraClimate changePrecipitationSea level riseEutrophication