Process model of fire ecology and succession in a mixed-conifer forest

Journal Article · Sun Jan 01 04:00:00 EST 1984 · Ecology; (United States)

DOI:https://doi.org/10.2307/1937768· OSTI ID:5230551

Kercher, J R; Axelrod, M C

A forest succession simulator, SILVA, has been developed for the mixed-conifer forest (seven major species) of the Sierra Nevada, California, to simulate the effects of fire on forest dynamics. SILVA is an extensive modification of a simulator for forests of the northeastern United States. The simulation includes the time development of the growth in tree diameter, tree height, and leaf-area index. Recruitment and mortality are modeled stochastically. Modifications include fire ecology, temporal seed-crop patterns, and seedling-survival factors unique to Sierra Nevada forests. The probability of mortality from fire is determined by the height of crown scorch (a function of fire intensity, diameter at breast height, and bark thickness). The model simulates the dynamic and structural responses of communities to many factors. For 500-yr simulations from an initial clear-cut condition, the time-averaged basal-area ratios of Pinus ponderosa to Abies concolor were 5.2:1 and 1:16 for elevations of 1524 m and 1829 m, respectively. At 1524 m, the ratio of P. ponderosa to A. concolor decreased 59% when fire suppression was introduced. Fire provides P. ponderosa with a strong competitive advantage. Its growth form and growth rate are significant factors in its ability to evade fire. Rank correlations of species were compared with data for stands of ponderosa pine and white fir. Correlations were significant at 1% and 10% levels, respectively.

• Research Organization: Lawrence Livermore National Lab., CA
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5230551
• Journal Information: Ecology; (United States), Journal Name: Ecology; (United States) Vol. 65:6; ISSN ECOLA
• Country of Publication: United States
• Language: English

Related Subjects

510100* -- Environment
Terrestrial-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
BASELINE ECOLOGY
BIOLOGICAL EFFECTS
BIOLOGICAL VARIABILITY
CALIFORNIA
CONIFERS
ECOLOGICAL SUCCESSION
ECOLOGY
FEDERAL REGION IX
FIRES
FORESTS
GROWTH
MATHEMATICAL MODELS
MORTALITY
NORTH AMERICA
PINES
PLANT GROWTH
PLANTS
POPULATION DYNAMICS
SEEDLINGS
SIMULATION
TREES
USA