Using ecological site information to develop drought response strategies

TitleUsing ecological site information to develop drought response strategies
Publication TypeConference Paper
Year of Publication2019
AuthorsBrown JR, Reyes J.T., Elias EH, Steele C, Wyndham A.
Conference NameUniversities Council on Water Resources
Date Published06/11/2019

Ecological Sites (ES) are interpretive groupings of static soil properties with unique climate, geomorphic and edaphic properties.  They can be mapped using National Cooperative Soil Survey tools and are supported by standardized, databased descriptions that include spatial biophysical attributes (eg soil depth, texture) and temporal behaviors (eg vegetation dynamics, disturbance responses).  In this project, we used ecological site information to evaluate the potential impact of drought conditions and to develop potential response strategies in two Major Land Resource Areas (MLRAs).  MLRA 69 in SE Colorado is characterized by mollisols, short grass prairie vegetation and extensive livestock grazing/dryland small grains.  MLRA in SE Arizona is characterized by aridisols, desert shrub/oak woodland/desert grassland vegetation and is used for livestock grazing.  We developed drought vulnerability assessment criteria to rank impacts on specific management units and to serve as a basis for developing strategic responses.  The primary threat of drought in MLRA 69 is reduced livestock forage and mid-term suppression of forage production post-drought, including ranch-level economic impacts.   Soils and vegetation are relatively well-adapted to drought and have substantial capacity for recovery, but economic stability is more fragile.  MLRA 41 has experienced, and continues to, experience short, medium and long-term drought impacts.  Short term impacts include reduced forage production; medium term impacts are primarily suppressed forage production post-drought; and long-term impacts include grass to shrub transitions and soil degradation.  Within each MLRA, there were substantial differences among ES, both in terms of reduction of forage production and in long-term recovery post drought.  These differences offer opportunities for managers to develop drought responses by selectively destocking management units as drought progresses and restocking post drought.