Encroachment of Juniperus species as a socio-ecological problem on private rangelands
Ecological models, resiliency theory and quantitative observation all indicate that the increased dominance of woody plants on Great Plains grasslands is a major threat to agriculture and conservation of grassland ecosystems. It is generally agreed that the dominant driver of invasion is fire suppression and restoration of fire regimes is the best approach to restore grasslands. Models predict that conversion of grassland to woodland can happen as quickly as 25-45 years and have identified thresholds for associated tree size and herbaceous biomass (fine fuel) that are related to fire frequency, fire intensity and other fuel-load altering processes. Our ecological understanding of the conversion process has progressed over the past several decades because of sound ecological studies, but patterns predicted by models are often incomplete in the privately owned landscapes of the Southern Great Plains.
Sociological drivers exist that explain these patterns and are influenced by many social entities that range in scale from the federal government to the individual land owner. The traditional network of government agencies, such as USDA-NRCS and University Cooperative Extension Services, combined with the development of land-owner cooperatives, user groups (patch-burn working group) and a Great Plains Fire Science Exchange has limited the invasion of these fire-sensitive trees in many places. Socio-ecological relationships among government agencies, land-owners and these new emergent organizations have managed to develop approaches to overcome thresholds and barriers predicted by the ecological models.