Geography as destiny? Social and ecological resilience in rangelands of the American southwest

Background/Question/Methods

Social-ecological systems perspectives focus on the reciprocal relationships between human and natural ecosystem elements and how these interactions determine human well-being, ecological state change, and land use change. In the arid southwestern US, which is dominated by ranching, a deeper understanding of social-ecological relationships is critical because land use change is accelerating. Productive cattle ranches, for example, can remain within family ownership for generations, whereas limited ecological potential, ecological degradation, and the “impermanence syndrome” can lead to repeated sales of other ranches. We asked whether we could predict expressions of social resilience (intrafamilial transfer of ownership vs. repeated ranch turnover to new owners) as a function of biophysical and geographic variables. In other words, are some ranches prone to failure? We studied an area dominated by federal public land (Bureau of Land Management grazing allotments) in southwestern New Mexico, USA. We examined the relationships of 1) frequency of ranch turnover and 2) intrafamilial transfer with variables related to 3) ecological resilience (soils, climate, departure from reference state) and 4) factors that may contribute to the perception of ranch impermanence (grazing allotment size and distance to the US-Mexico border and major cities). The dataset included 432 grazing allotments examined over a 70 year period.

Results/Conclusions

Our analysis supported the hypothesis that ranch ownership dynamics were related to ecological potential, ecological state, and ranch impermanence factors. The frequency of ranch turnover was positively related to the dominance of low-resilience (sandy) soils and degraded ecological states and negatively related to mean annual precipitation, distance from the US-Mexico border, and distance to major cities. Ranch turnover was positively related to grazing allotment size, perhaps because the largest allotments were established in the poorest soils under the Taylor Grazing Act (1934). In contrast, intrafamilial transfers were positively related to mean annual precipitation and distance from cities but negatively related to allotment size and the dominance of sandy soils. Thus, geographic position within the study area appears to be an important determinant of past land ownership dynamics. Future land use changes, including urban expansion, energy development, and establishment of conservation areas might also be predicted by ecological and impermanence factors.