Projecting the Hydrologic Impacts of Climate Change on Montane Wetlands

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.

Experimental evidence for beneficial effects of projected climate change on hibernating amphibians

“…Moreover, when exposed to a shorter and/or milder winter, survivors also had larger body mass after hibernation, which is likely to have long-lasting effects by enhancing further survival and fecundity142342. While other consequences of climate change, such as an increasing probability of mass mortalities in aquatic larvae due to premature pond-desiccation, the spread of invasive predators and infectious diseases are likely to have negative effects on anuran populations located in the temperate zone and at high altitudes and latitudes131325304344, the benefits arising from milder and shorter winters may somewhat dampen these effects on population persistence273132. Further studies testing the general applicability of our results across several amphibian taxa, under different climate change scenarios and during several life stages are urgently needed.…”

Hydrological Function of a Mountain Fen at Low Elevation Under Dry Conditions

“…Hydrological behaviour is thus a critical control on mountain fen ecological and biogeochemical function, including water and carbon storage (Crockett, Ronayne, & Cooper, ; Harbert & Cooper, ; Millar, Cooper, Dwire, Hubbard, & von Fischer, ). Mountain fens are expected to be highly sensitive to changing climate as what are thought to be their primary water supplies (precipitation, snowpack) are directly influenced by climate (Lee et al, ).…”

Multistate occupancy modeling improves understanding of amphibian breeding dynamics in the Greater Yellowstone Area

“…, Lee et al. ). We assessed covariates for multicollinearity by considering Pearson correlation coefficients ( r ) and eliminated covariates that had high correlations ( r ≥ 0.60) from appearing in the same model.…”