Effects of Climate Change on Ecosystem Services in the Northern Rockies

Abstract

Ecosystem services are increasingly valued on federal lands, beyond just their economic value. Climate change effects will vary greatly within different subregions of the Northern Rockies, with some ecosystem services being affected in the short term and others in the long term. Of the many ecosystem services provided in the Northern Rockies, eight are considered here, including annual water yield, water quality, wood products, minerals and mineral extraction, forage for livestock, viewsheds and air quality, regulation of soil erosion, and carbon sequestration. Although annual water yield is not expected to change significantly, timing of water availability will likely shift, and summer flows may decline. These changes may result in some communities experiencing summer water shortages, although reservoir storage can provide some capacity. Rural agricultural communities will be disproportionately affected by climate change if water does become limiting. Water quality will also decrease in some locations if wildfires and floods increase, adding sediment to rivers and reservoirs. Hazardous fuel treatments, riparian restoration, and upgrading of hydrologic infrastructure can build resilience to disturbances that damage water quality. Forage for livestock is expected to increase in productive grasslands as a result of a longer growing season and in some cases elevated carbon dioxide. Therefore, ranching and grazing may benefit from climate change. Primary effects on grazing include loss of rural population, spread of nonnative grasses, and fragmentation of rangelands. Viewsheds and air quality will be negatively affected by increasing wildfires and longer pollen seasons. A growing percentage of the Northern Rockies population will be in demographic groups at risk for respiratory and other medical problems on days with poor air quality. Hazardous fuel treatments can help build resilience to disturbances that degrade air quality. Carbon sequestration will be increasingly difficult if wildfires, insect outbreaks, and perhaps plant disease increase as expected, especially in the western part of the Northern Rockies. At the same time, managing forests for carbon sequestration is likely to become more important in response to national policies on carbon emissions. Hazardous fuel treatments can help build resilience to disturbances that rapidly oxidize carbon and emit it to the atmosphere.