Recovery Plan for the Northern Spotted Owl - DRAFT

growth often increases (Reinhardt and Ryan 1988), while residual Douglas-firmay show no change in radial growth lixcrement.If a crown fire does occur, it kills all the trees in the stand. Herbs and shrubsmay dominate the floristics of early succession, with some herbs (e.g.,Epilobium angustifoliurn) peaking and declining within the same decade(Stickney 1986). Western larch has light-winged seeds, which can blow onto aburned site from adjacent stands or from lightly scorched cones in the firekilledstand (Haig et al. 1941). Lodgepole pine, if present on the site, willestablish from serotinous cones in the area. If the crown fires have beenspaced more than 150 years apart, western larch is the most probable treedominant at the time of disturbance, because lodgepole pine, the other earlyseral species with fast growth, is short-lived and may have been killed bymountain pine beetles (Haig et al. 1941). Where the crown fire interval isshorter than 150 years, lodgepole pine will at least share dominance in thepost-fire tree cohort (Gabriel 1976, Antos 1977, Antos and Habeck 1981).However, if the stand is repeatedly underburned after lodgepole pine establishment,lodgepole pine will be eliminated because of its thin bark in favor ofwestern larch, ponderosa pine, and Douglas-fir.If two crown fires occur in quick succession, the site may revert to a brushfield(Antos and Habeck 1981), as neither western larch nor lodgepole pine survivessuch fires in the pole stage (Davis et al. 1980). Where a single crown fireoccurs, stand establishment usually includes individuals of other species aswell as lodgepole pine and larch. On dry sites, ponderosa pine may be included.On average sites, Douglas-fir and grand fir are normally present, andon moist sites western white pine may be a codominant. None of the associatedspecies typically grows as fast as western larch and lodgepole pine (Haig etal. 1941, Cobb 1988). Individual species create different strata over time,although all may establish in the same time period. On a series of even-agedstands in eastern Washington that regenerated after crown fires, Cobb (1988;Figure F.8) found western larch to be a consistent dominant, with lodgepolepine sharing dominance on some sites. Douglas-fir and grand fir showed avariety of stratification patterns but always in intermediate or suppressedcrown positions.Low intensity fires in these stands increase the relative dominance of westernlarch, ponderosa pine, and/or Douglas-fir over their associates because of theircrown position relative to grand fir, and thicker bark than lodgepole pine ondominant trees. Substantial understory development, perhaps after thebreakup of lodgepole pine in the canopy, will encourage an understoryreinitiation stage in stand development (Oliver 1981) which may be associatedwith increased crown fire potential and another set of multiple successionalpost-fire pathways.A successional model of western larch/Douglas-fir forests, including firedynamics was developed by Keane et al. (1990) for the Douglas-fir series inMontana. The model outputs generated by fire return intervals of 10, 20, and50 years, and a no-fire situation are shown in Figure F.9. Ponderosa pine ismost dominant in the more frequent fire return interval simulations. In theDouglas-fir series simulation, Douglas-fir is the most shade-tolerant speciesincluded and dominates the no-fire scenario. In the East Cascades subregion,the Douglas-fir series has little larch, and the fire scenarios would favorponderosa pine with some Douglas-fir. The grand fir series is more commonwhere larch is found; Douglas-fir in this series behaves more like larch whilegrand fir is the most shade-tolerant species. Substituting those species in thegraphs gives a general idea of this alternative succession scenario: for example,in the no-fire scenario, larch, ponderosa pine, and Douglas-fir would declineand grand fir would increase.464