Format

Send to

Choose Destination
Proc Natl Acad Sci U S A. 2016 Feb 23;113(8):1978-86. doi: 10.1073/pnas.1512650113. Epub 2016 Feb 8.

Do geographically isolated wetlands influence landscape functions?

Author information

1
School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611; mjc@ufl.edu.
2
Department of Biology, Western University, London, ON, Canada N6A 5B7;
3
National Center for Environmental Assessment, United States Environmental Protection Agency, Washington, DC 20460;
4
Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON, Canada N2L 3G1;
5
Department of Wildlife, Fisheries, and Conservation Biology, University of Maine, Orono, ME 04469;
6
School of Public Health and Environmental Affairs, Indiana University, Bloomington, IN 47405;
7
CSS-Dynamac Corporation, Cincinnati, OH 45268;
8
School of Natural Resource Sciences, North Dakota State University, Fargo, ND 58108-6050;
9
Odum School of Ecology, The University of Georgia, Athens, GA 30602;
10
National Exposure Research Laboratory, United States Environmental Protection Agency, Cincinnati, OH 45268;
11
Soil and Water Science Department, University of Florida, Gainesville, FL 32611;
12
Region 4, United States Environmental Protection Agency, Athens, GA 30605;
13
Joseph W. Jones Ecological Research Center, Newton, GA 39870;
14
Department of Geographical Sciences, University of Maryland, College Park, MD 20742;
15
Western Ecology Division, National Health and Environmental Effects Research Laboratory, United States Environmental Protection Agency, Corvallis, OR 97333;
16
Department of Integrative Biology, University of South Florida, Tampa, FL 33620;
17
CDM Smith, Inc., Indianapolis, IN 46204;
18
Department of Forest Resources and Environmental Conservation, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061;
19
Northern Prairie Wildlife Research Center, United States Geological Survey, Jamestown, ND 58401;
20
Office of Wetlands, Oceans, and Watersheds, United States Environmental Protection Agency, Washington, DC 20460;
21
School of Geosciences, University of South Florida, Tampa, FL 3362;
22
Wetland and Aquatic Research Center, United States Geological Survey, Gainesville, FL 32653.

Abstract

Geographically isolated wetlands (GIWs), those surrounded by uplands, exchange materials, energy, and organisms with other elements in hydrological and habitat networks, contributing to landscape functions, such as flow generation, nutrient and sediment retention, and biodiversity support. GIWs constitute most of the wetlands in many North American landscapes, provide a disproportionately large fraction of wetland edges where many functions are enhanced, and form complexes with other water bodies to create spatial and temporal heterogeneity in the timing, flow paths, and magnitude of network connectivity. These attributes signal a critical role for GIWs in sustaining a portfolio of landscape functions, but legal protections remain weak despite preferential loss from many landscapes. GIWs lack persistent surface water connections, but this condition does not imply the absence of hydrological, biogeochemical, and biological exchanges with nearby and downstream waters. Although hydrological and biogeochemical connectivity is often episodic or slow (e.g., via groundwater), hydrologic continuity and limited evaporative solute enrichment suggest both flow generation and solute and sediment retention. Similarly, whereas biological connectivity usually requires overland dispersal, numerous organisms, including many rare or threatened species, use both GIWs and downstream waters at different times or life stages, suggesting that GIWs are critical elements of landscape habitat mosaics. Indeed, weaker hydrologic connectivity with downstream waters and constrained biological connectivity with other landscape elements are precisely what enhances some GIW functions and enables others. Based on analysis of wetland geography and synthesis of wetland functions, we argue that sustaining landscape functions requires conserving the entire continuum of wetland connectivity, including GIWs.

KEYWORDS:

connectivity; navigable waters; significant nexus

PMID:
26858425
PMCID:
PMC4776504
DOI:
10.1073/pnas.1512650113
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center