Part 4: Forest Succession

The ecosystems within the area that burned in the Hayman Fire have a long history of fire (see part 1 of this chapter). It follows, therefore, that all of the native species and populations in this area probably have one or more mechanisms for enduring fire or becoming reestablished after fire and that no native species is likely to become extinct as a result of the direct effects of the Hayman Fire. It also follows that active rehabilitation is not required for all of the burned area. In fact, much or even most of the area is likely to recover normally without intervention, and in some areas our well-intentioned rehabilitation efforts actually could interfere with natural recovery processes. Despite the general expectation just stated, ecosystem recovery and native species persistence is likely to be problematic within certain portions of the Hayman burn area. In other parts of the burned area, postfire trajectories may lead to ecological conditions different from what existed just before the Hayman Fire, but nevertheless within the historical range of variability for this ecosystem. Therefore, in addressing this question, we describe three potential postfire trends in vegetation development, and indicate generally where in the Hayman landscape each trend is likely to be manifest. The three trends are (1) development of vegetation structure, composition, and function similar to what existed just before the Hayman Fire, (2) development of vegetation that is different from prefire conditions but within the historical range of variability, and (3) development of vegetation that is different from prefire conditions and also is dissimilar to or at extremes of the historical range of variability for this ecosystem. Vegetation structure refers to overall physiognomy, for example, dense forest, open forest, shrubland, or grassland. Composition refers to the species present and the relative abundance of each species. Function refers to ecosystem processes of energy flow, material cycling, disturbances, and others. Our predictions are summarized generally in table 6.