USDA Northern Plains Regional Climate Hub assessment of climate change variability and adaptation and mitigation strategies

Authors: Derner, Justin; JOYCE, LINDA - Forest Service (FS); GUERRERO, RAFAEL - Natural Resources Conservation Service (NRCS, USDA); STEELE, RACHEL - US Department Of Agriculture (USDA)

Submitted to: USDA Miscellaneous Publication 1343
Publication Type: Government Publication
Publication Acceptance Date: 5/3/2015
Publication Date: 5/4/2015
Citation: Derner, J.D., Joyce, L., Guerrero, R., Steele, R. 2015. USDA Northern Plains Regional Climate Hub assessment of climate change variability and adaptation and mitigation strategies. USDA Miscellaneous Publication 1343. Available: climatehubs.oce.usda.gov/sites/default/files/Northern%20Plains%20Vulnerability%20Assessment%205_1_2015_Compressed.pdf.

Interpretive Summary: Changing climatic conditions (for example, longer and warmer growing seasons, changes in distribution of seasonal precipitation, and warmer temperatures) can affect decision-making for ranchers, farmers and forest land owners in the Northern Plains (Montana, Wyoming, Colorado, North Dakota, South Dakota, and Nebraska). For the major production systems and crops in the Northern Plains, this vulnerability assessment highlights the risks with changing climate, vulnerabilities of the production system/crop, and provides a suite of adaptation strategies that land managers can employ to enhance climate smart/informed decision-making to reduce enterprise risk and increase resilience of these working lands. Some of the potential adaptation strategies include: 1) enhancement of soil organic matter and soil health (and as a result greater water holding capacity and enhanced nutrient cycling) by cover crops, especially mixtures involving legumes, 2) integrated crop-livestock systems with strategies of utilizing aftermath grazing and cover crop grazing for feeder cattle, 3) adaptive grazing management through providing flexibility to match forage availability/demand, 4) grassbanking (resting of pastures for >1 year) to provide forage during dry periods, 5) proactive management strategies to reduce invasive species, reduce risk of wildfires, and promote resiliency of native plant communities, and 6) increased attention to seasonal precipitation/temperature and drought forecasting resources (e.g., http://drought.gov/drought/).

Technical Abstract: Ranchers, farmers and forest land owners in the Northern Plains have experienced warmer temperatures (1 to 1.5 degrees F), longer growing seasons (about a week and a half) and generally more precipitation (5 to >15% increases over the eastern 2/3 of this region) over the past twenty years compared to most of the 20th century. As a result, land use changes and shifts in production systems have occurred with 1) cattle increasing with stock coming in from drought-stricken areas of California and Texas/Oklahoma, and 2) displacement of wheat acres in counties in the eastern part of the Northern Plains by substantial increases in corn and soybean acres. Projected climatic changes are expected to result in continued longer and warmer growing seasons with mountain areas most impacted, and this will alter the amount of snowpack and timing of snowmelt to impact runoff to reservoirs for irrigation use on crops, hayland, recreation, navigation, fish habitat and human consumptive use. Predicted increases in winter, spring and fall seasonal precipitation (and slightly drier summers) will result in no changes or reductions in consecutive dry days in this region, even though growing seasons will be longer and temperatures warmer. As a result, the expectation is that corn and soybeans production systems will continue to move north-northwest in the region, at further expense of wheat and small grains (e.g., barley) with expansion into southern parts of Canadian provinces of Saskatchewan and Alberta. Increased emphasis on conservation measures and adaptation strategies will be needed to deal with vulnerabilities of altered snowpack levels with earlier snow melt that affect reservoir management for irrigation, decreases in levels of groundwater aquifers, water runoff and quality impacts from soil erosion associated with a higher frequency of downpours (high intensity rainfall) and increased pest and weed pressure for crops. Conservation efforts including mitigation strategies involving increased irrigation efficiency (i.e., more crop per drop),and new technology for subsurface irrigation, and adaptation strategies involving enhancement of soil organic matter and soil health (and as a result greater water holding capacity and enhanced nutrient cycling) by cover crops, especially mixtures involving legumes, and integrated crop-livestock systems. Additionally, genetic development of varieties through sophisticated breeding programs involving molecular approaches can help offset negative impacts of rising temperatures and drought. Dryland crops can utilize conservation efforts with adaptation strategies that include intensification of management to provide nearly year-round ground cover to reduce soil exposure to water/wind erosion and increase soil health by double cropping and using cover crops that can provide soil nitrogen through mixtures with legumes. Vulnerabilities for confined livestock are predicted higher temperature humidity indexes (THI), increased pest pressure (e.g., ectoparasites) due to earlier and longer, as well as warmer growing seasons, and possible water runoff and quality issues associated with increased frequency of very heavy precipitation. Here, livestock producers will be implementing mitigation practices such as providing partial to total shelter to reduce heat stress associated with extreme temperatures, and housing systems may need to be modified to provide increased temperature regulation. Also, livestock producers can use adaptation strategies of utilizing aftermath grazing and cover crop grazing for feeder cattle, altering timing of placement of feeder animals and subsequent finishing time of these animals to reduce stress associated with heat waves, and considering alternative livestock breeds, class or species which more closely match the environment. For ranchers with grazing livestock, the difficulty is matching f