Wednesday, November 7, 2007 - 10:45 AM
323-4
A Comprehensive, Quantitative Assessment of the Soils of Coastal Wetlands in Hawai'i.
Coastal wetlands are important features in the landscape that provide numerous ecosystem services including water quality improvement, flood attenuation, and carbon sequestration. Despite their importance, a comprehensive, quantitative assessment of the soils of these wetlands in the state of Hawai’i has yet to occur. In response to this need, the goal of this presentation is to assess the soil properties of created, restored, and semi-natural wetlands of Hawai’i . To accomplish this goal, we sampled 40 coastal wetlands sites in both freshwater and estuarine settings from the five major Hawaiian Islands (Kaua'i, Oahu, Moloka'i, Maui, and Hawai'i ). We sampled transects that spanned the major hydrologic gradients at each site. Locations of all sampling points were identified with a GPS. Preliminary results indicated that there were significant differences in soil properties such as moisture, bulk density, texture, and organic matter across the hydrologic gradients and among the different types of sites. We also investigated the effects of watershed size and land-use on the soil nutrient levels at each site. Sites in watersheds with higher forested land cover had lower soil nutrient levels than sites in more urban or agricultural watersheds. As more soil analyses are completed, we will continue to conduct additional statistical analyses of the data. This is the first integrated assessment of coastal wetland soils in Hawai’i . Results of this study will be of interest to soil scientists, managers, and policy makers in providing feedback on wetland creation and restoration activities, setting water quality standards for Hawaiian wetlands, and prioritizing sites for conservation.
Recorded presentation