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C. T. Dyrness. Early Stages of Plant Succession Following Logging and Burning in the Western Cascades of Oregon. Ecology, Vol. 54, No. 1. (Jan., 1973), pp. 57-69

Vegetative changes were documented for 7 years on permanent plots located in three clearcut logged units in the western Cascade Mountains of Oregon. Plant cover and composition were observed the year prior to logging the old-growth Douglas-fir forest, after logging but before burning, and during each of five growing seasons following broadcast slash burning. Total plant cover was 15.2, 49.3, and 75.5% in the first, second, and fifth years after slash burning, respectively. Invading herbaceous species dominated from the second through fourth growing seasons after burning, but by the fifth year residual herbaceous species regained dominance. Differences in disturbance from logging and burning strongly influenced successional trends. In undisturbed soil areas, residual species, such as Acer circinatum, Oxalis oregana, and Gaultheira shallon, dominated. Areas disturbed by logging but unburned supported a wide variety of both residual and invader species. Light to severely burned sites were largely occupied by invaders such as Ceanothus velutinus,Epilobium angustifolium, and E. paniculatum. Although often obscured by varying degrees of disturbance, relationships between early stages of succession and prelogging plant community were discernible. For example, of the species considered characteristic of five undisturbed plant communities, only 13 percent were absent from the plots 5 years after burning. The invaders Ceanothus velutinus, Agoseris grandiflora, and Gnaphalium microcephalum var. thermale were restricted to sites previously supporting rather xeric communities; while Rubus leucodermis and Anaphalis margaritacea were found on plots characteristic of the more mesic communities.

Charles B. Halpern. Early Successional Patterns of Forest Species: Interactions of Life History Traits and Disturbance. Ecology, Vol. 70, No. 3. (Jun., 1989), pp. 704-720

Patterns of abundance were examined for vascular plant species during 21 years of succession in two clear-cut and burned Douglas-fir forests in the western Cascade Range of Oregon. A majority of forest understory species persisted through disturbance. Most colonizing species established within 2 year s after burning. Individualistic species responses were described by a series of broadly overlapping, unimodal curves of constancy and canopy cover, differing in time of initiation, duration, and magnitude. Thus, early successional change was characterized by gradual shifts in the abundance of generally persistent species. Eleven population patterns (species groups) were identified. Interactions of life history traits and disturbance explain the temporal trends of the most common species. Within the groups of invading species, the timing of initial establishment, as well as the timing and magnitude of peak abundance were related to the origin of propagules, phenological traits, potential for vegetative expansion, and temporal and spatial variation in disturbance. Abundance patterns of invading species were also influenced by stochastic and historical factors. Contrasting responses of species between sites reflected differences in histories of logging and slash burning. Within the groups of residual species, temporal patterns of abundance reflected initial species distributions, resistance to logging and burning disturbance, mode of reproduction, morphological traits, and spatial variation in disturbance intensity. These observations suggest that early secondary succession in Douglas-fir forests has a deterministic component, founded in the life history traits of the available species, and a stochastic component reflecting site history and variation in disturbance.

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The CFR home page is also a good source for other forestry links. It can be reached by going to: http://www.cfr.washington.edu/If you have any links, articles or abstracts you would like to see included in the SMC newsletter, please e-mail them to: moshea@u.washington.edu

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