Regional hydrologic and carbon balance responses of forests resulting from potential climate change

Abstract

The projected response of coniferous forests to a clLmatic change scenario of doubled atmospheric CO2, air temperature of +4 ~ and +10% preeipitation was studied using a computer simulation model of forest ecosystem processes. A topographically complex forested region of Montana was simulated to study regional climate change induced forest responses. In general, increases of 10-20% in LAI, and 20-30% in evapotranspiration (ET) and photosynthesis (PSN) were projected. Snowpack duration decreased by 19-69 days depending on location, and growing season length increased proportionally. However, hydrologic outflow, primarily fed by snowmelt in this region, was projected to decrease by as much as 30%, which could virtually dry up rivers and irrigation water in the future.To understand the simulated forest responses, and explore the extent to which these results might apply continentally, seasonal hydrologic partitioning between outflow and ET, PSN, respiration, and net primary production (NPP) were simulated for two contrasting climates of Jacksonville, Florida (hot, wet) and Missoula, Montana (cold, dry). Three forest responses were studied sequentially from; climate change alone, addition of CO2 induced tree physiological responses of -30% stomatal conductance and +30% photosynthetic rates, and finally with a reequilibration of forest leaf area index (LAI), derived by a hydrologic equilibrium theory. NPP was projected to increase 88%, and ET 10%, in Missoula, MT, yet decrease 5% and 16% respectively for Jacksonville, FL, emphasizing the contrasting forest responses possible with future climatic change.

Climate change impacts and adaptation in forest management: a review

“…Most early studies of forest ecosystem responses to climate change were built around ecosystem process models at various scales (Graham et al 1990;Running and Nemani 1991;Rastetter et al 1991). A number of recent studies have investigated the effects of past and current climate change on forest processes, often with surprising effects (Groffman et al 2012).…”

Wildland fire in ecosystems: effects of fire on flora

“…The effects will likely cascade throughout ecosystems. For example, increased water use efficiency of upland plants can be expected to reduce stream flows (Running and Nemani 1991), thereby affecting aquatic systems.…”

Estimation of Canopy Water Content by Means of Hyperspectral Indices Based on Drought Stress Gradient Experiments of Maize in the North Plain China

“…Generally, canopy water content (CWC) and the mean leaf equivalent water thickness at the canopy level ( ̅̅̅̅̅̅̅ ) are widely used for describing the vegetation water status [6,7]. Since many biogeochemical processes including photosynthesis, evapotranspiration and net primary production are closely related to vegetation CWC and ̅̅̅̅̅̅̅ [8][9][10], therefore, gaining a thorough and better understanding of vegetation CWC and ̅̅̅̅̅̅̅ will play an important role in mapping and monitoring the conditions of terrestrial ecosystems such as environmental stress [11], wildfire potential [12] or soil moisture retrieval [13].…”