Disturbance patterns in southern Rocky Mountain forests

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The pattern of landscape diversity in the southern Rocky Mountains has been described as resulting from "two superimposed vegetation patterns: the distribution of species along gradients of limiting factors, and patterns of disturbance and recovery within the communities at each point along the environmental gradients" (Romme and Knight 1982). The previous chapter in this volume has emphasized the first pattern whereas this chapter emphasizes the role of natural disturbance in creating landscape patterns. A conceptual framework for analyzing the characteristics and consequences of disturbance is the concept of disturbance regime, or the spatial and temporal characteristics of disturbances in a particular landscape (Paine and Levin 1981, White and Pickett 1985). The key descriptors of a disturbance regime are:(1) spatial distribution, 2) frequency, 3) size of the area disturbed, 4) mean return interval, 5) predictability, 6) rotation period, 7) magnitude or severity, and 8) the synergistic interactions of different kinds of disturbances. Within an area of otherwise homogeneous habitat, variations in these parameters are major determinants of landscape heterogeneity and, consequently, must be considered in evaluating the fragmentation caused by forest cutting and road construction. Although numerous case studies have been done on vegetation and ecosystem response to disturbance for the southern Rocky Mountains, relatively little work has been done on disturbance regimes per se. To inform discussions of the relationship of landscape patchiness to natural disturbances and issues of fragmentation, this chapter will emphasize four "key" questions about disturbance regimes: 1. How do disturbance regimes vary along environmental gradients? 2. How have humans altered natural disturbance regimes? 3. How do disturbance interactions affect vegetation responses as well as the occurrence and spread of subsequent disturbances? 4. How does climatic variability affect disturbance regimes and vegetation response to disturbances?

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ELECTRONIC FILE - Ecology

SWAP (2/19/2016) citation (with minor correction):
Veblen TT. 2000. Disturbance patterns in southern Rocky Mountain forests. In: Knight RL, Smith FW, Buskirk SW, et al., editors. Forest fragmentation in the southern Rocky Mountains. Boulder (CO): University Press of Colorado. p. 31–54. [accessed 2016 Feb 04]. http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1131&context=b....