Abstract
The alteration of fresh and marine water cycling is likely to occur in coastal ecosystems as climate change causes the global redistribution of precipitation while simultaneously driving sea-level rise at a rate of 2-3 mm yr-1. Here, we examined how precipitation alters the ecological effects of ocean water intrusion to coastal dunes on two oceanic carbonate islands in the Bahamas. The approach was to compare sites that receive high and low annual rainfall and are also characterized by seasonal distribution (wet and dry season) of precipitation. The spatial and temporal variations in precipitation serve as a proxy for conditions of altered precipitation which may occur via climate change. We used the natural abundances of stable isotopes to identify water sources (e.g., precipitation, groundwater and ocean water) in the soil-plant continuum and modeled the depth of plant water uptake. Results indicated that decreased rainfall caused the shallow freshwater table on the dune ecosystem to sink and contract towards the inland, the lower freshwater head allowed ocean water to penetrate into the deeper soils, while shallow soils became exceedingly dry. Plants at the drier site that lived nearest to the ocean responded by taking up water from the deeper and consistently moist soil layers where ocean water intruded. Towards the inland, decreased rainfall caused the water table to sink to a depth that precluded both recharge to the upper soil layers and access by plants. Consequently, plants captured water in more shallow soils recharged by infrequent rainfall events. The results demonstrate dune ecosystems on oceanic islands are more susceptible to ocean water intrusion when annual precipitation decreases. Periods of diminished precipitation caused drought conditions, increased exposure to saline marine water and altered water-harvesting strategies. Quantifying species tolerances to ocean water intrusion and drought are necessary to determine a threshold of community sustainability. Published 2010. This article is a US Government work and is in the public domain in the USA.
| Original language | English |
|---|---|
| Pages (from-to) | 1860-1869 |
| Number of pages | 10 |
| Journal | Global Change Biology |
| Volume | 16 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 1 2010 |
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Keywords
- Caribbean islands
- Climate change
- Coastal plants
- Eco physiology
- Ocean water intrusion
- Oxygen isotopes
- Water cycle
- Water relations
ASJC Scopus subject areas
- Ecology
- Global and Planetary Change
- Environmental Science(all)
- Environmental Chemistry
Cite this
Decreased precipitation exacerbates the effects of sea level on coastal dune ecosystems in open ocean islands. / Greaver, Tara L.; Sternberg, Leonel.
In: Global Change Biology, Vol. 16, No. 6, 01.06.2010, p. 1860-1869.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Decreased precipitation exacerbates the effects of sea level on coastal dune ecosystems in open ocean islands
AU - Greaver, Tara L.
AU - Sternberg, Leonel
PY - 2010/6/1
Y1 - 2010/6/1
N2 - The alteration of fresh and marine water cycling is likely to occur in coastal ecosystems as climate change causes the global redistribution of precipitation while simultaneously driving sea-level rise at a rate of 2-3 mm yr-1. Here, we examined how precipitation alters the ecological effects of ocean water intrusion to coastal dunes on two oceanic carbonate islands in the Bahamas. The approach was to compare sites that receive high and low annual rainfall and are also characterized by seasonal distribution (wet and dry season) of precipitation. The spatial and temporal variations in precipitation serve as a proxy for conditions of altered precipitation which may occur via climate change. We used the natural abundances of stable isotopes to identify water sources (e.g., precipitation, groundwater and ocean water) in the soil-plant continuum and modeled the depth of plant water uptake. Results indicated that decreased rainfall caused the shallow freshwater table on the dune ecosystem to sink and contract towards the inland, the lower freshwater head allowed ocean water to penetrate into the deeper soils, while shallow soils became exceedingly dry. Plants at the drier site that lived nearest to the ocean responded by taking up water from the deeper and consistently moist soil layers where ocean water intruded. Towards the inland, decreased rainfall caused the water table to sink to a depth that precluded both recharge to the upper soil layers and access by plants. Consequently, plants captured water in more shallow soils recharged by infrequent rainfall events. The results demonstrate dune ecosystems on oceanic islands are more susceptible to ocean water intrusion when annual precipitation decreases. Periods of diminished precipitation caused drought conditions, increased exposure to saline marine water and altered water-harvesting strategies. Quantifying species tolerances to ocean water intrusion and drought are necessary to determine a threshold of community sustainability. Published 2010. This article is a US Government work and is in the public domain in the USA.
AB - The alteration of fresh and marine water cycling is likely to occur in coastal ecosystems as climate change causes the global redistribution of precipitation while simultaneously driving sea-level rise at a rate of 2-3 mm yr-1. Here, we examined how precipitation alters the ecological effects of ocean water intrusion to coastal dunes on two oceanic carbonate islands in the Bahamas. The approach was to compare sites that receive high and low annual rainfall and are also characterized by seasonal distribution (wet and dry season) of precipitation. The spatial and temporal variations in precipitation serve as a proxy for conditions of altered precipitation which may occur via climate change. We used the natural abundances of stable isotopes to identify water sources (e.g., precipitation, groundwater and ocean water) in the soil-plant continuum and modeled the depth of plant water uptake. Results indicated that decreased rainfall caused the shallow freshwater table on the dune ecosystem to sink and contract towards the inland, the lower freshwater head allowed ocean water to penetrate into the deeper soils, while shallow soils became exceedingly dry. Plants at the drier site that lived nearest to the ocean responded by taking up water from the deeper and consistently moist soil layers where ocean water intruded. Towards the inland, decreased rainfall caused the water table to sink to a depth that precluded both recharge to the upper soil layers and access by plants. Consequently, plants captured water in more shallow soils recharged by infrequent rainfall events. The results demonstrate dune ecosystems on oceanic islands are more susceptible to ocean water intrusion when annual precipitation decreases. Periods of diminished precipitation caused drought conditions, increased exposure to saline marine water and altered water-harvesting strategies. Quantifying species tolerances to ocean water intrusion and drought are necessary to determine a threshold of community sustainability. Published 2010. This article is a US Government work and is in the public domain in the USA.
KW - Caribbean islands
KW - Climate change
KW - Coastal plants
KW - Eco physiology
KW - Ocean water intrusion
KW - Oxygen isotopes
KW - Water cycle
KW - Water relations
UR - http://www.scopus.com/inward/record.url?scp=77953666917&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77953666917&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2486.2010.02168.x
DO - 10.1111/j.1365-2486.2010.02168.x
M3 - Article
AN - SCOPUS:77953666917
VL - 16
SP - 1860
EP - 1869
JO - Global Change Biology
JF - Global Change Biology
SN - 1354-1013
IS - 6
ER -