Title | Nonlinear dynamics in arid systems: interactions among drivers and processes across scales |
Publication Type | Conference Paper |
Year of Publication | 2004 |
Authors | Peters DC, Havstad K |
Conference Name | Sixth Symposium on the Natural Resources of the Chihuahuan Desert Region |
Date Published | October 15, 2004 |
Conference Location | Alpine, TX |
ARIS Log Number | 171312 |
Keywords | arid systems, broad-scale drivers, Chihuahuan Desert, drivers, feedbacks, interactions, landscape contest, nonlinear dynamics, processes, scales, spatially contagious processes, threshold behavior |
Abstract | Conversion from perennial grasslands to shrub-dominated systems has occurred globally in arid and semiarid systems and regionally in the Chihuahuan Desert over the past 100-150 years. Broad-scale drivers, such as grazing and extreme drought, are often invoked to explain shrub invasion dynamics. We use long-term, spatially explicit data to show that these drivers are frequently insufficient to explain patterns in shrub invasion and grass persistence at the landscape scale. At the Jornada Experimental Range, we are developing a new conceptual framework to explain high temporal and spatial variation in landscape patterns and dynamics. Our framework focuses on five key aspects of these systems: (1) threshold behavior, (2) spatially contagious processes, (3) landscape context, (4) feedbacks between biotic and abiotic processes at multiple scales, and (5) landscape legacies. We show how accounting for these key aspects of system behavior can explain nonlinear dynamics across spatial and temporal scales. This talk provides the background for the remaining talks in the special session “Landscape linkages and cross-scale interactions in the Chihuahuan Desert.” |