Projecting the Hydrologic Impacts of Climate Change on Montane Wetlands

PLoS One. 2015 Sep 2;10(9):e0136385. doi: 10.1371/journal.pone.0136385. eCollection 2015.

Abstract

Wetlands are globally important ecosystems that provide critical services for natural communities and human society. Montane wetland ecosystems are expected to be among the most sensitive to changing climate, as their persistence depends on factors directly influenced by climate (e.g. precipitation, snowpack, evaporation). Despite their importance and climate sensitivity, wetlands tend to be understudied due to a lack of tools and data relative to what is available for other ecosystem types. Here, we develop and demonstrate a new method for projecting climate-induced hydrologic changes in montane wetlands. Using observed wetland water levels and soil moisture simulated by the physically based Variable Infiltration Capacity (VIC) hydrologic model, we developed site-specific regression models relating soil moisture to observed wetland water levels to simulate the hydrologic behavior of four types of montane wetlands (ephemeral, intermediate, perennial, permanent wetlands) in the U. S. Pacific Northwest. The hybrid models captured observed wetland dynamics in many cases, though were less robust in others. We then used these models to a) hindcast historical wetland behavior in response to observed climate variability (1916-2010 or later) and classify wetland types, and b) project the impacts of climate change on montane wetlands using global climate model scenarios for the 2040s and 2080s (A1B emissions scenario). These future projections show that climate-induced changes to key driving variables (reduced snowpack, higher evapotranspiration, extended summer drought) will result in earlier and faster drawdown in Pacific Northwest montane wetlands, leading to systematic reductions in water levels, shortened wetland hydroperiods, and increased probability of drying. Intermediate hydroperiod wetlands are projected to experience the greatest changes. For the 2080s scenario, widespread conversion of intermediate wetlands to fast-drying ephemeral wetlands will likely reduce wetland habitat availability for many species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Climate Change*
  • Droughts
  • Humans
  • Hydrology / methods*
  • Models, Statistical
  • Models, Theoretical
  • Northwestern United States
  • Regression Analysis
  • Seasons
  • Soil / chemistry
  • Water Movements*
  • Wetlands*

Substances

  • Soil

Grants and funding

The David H. Smith Conservation Research Fellowship Program funded MER's salary and field research (no grant number; smithfellows.org). The North Pacific Landscape Conservation Cooperative funded SL's salary, a workshop to share results, and equipment (USFWS grant #F11AC00080; http://www.northpacificlcc.org/). The Northwest Climate Science Center provided salary support for SL, MER, AFH, JJL, and MH and funding for field research (USGS grant #GS276A-A; http://www.doi.gov/csc/Northwest/index.cfm). The Canada Research Chairs Program provided salary for WJP (http://www.chairs-chaires.gc.ca/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.