Population differentiation in tree-ring growth responses of white fir (Abies concolor) to climate: Implications for predicting forest responses to climate change
Forest succession models and correlative models have predicted 200-650 kilometer shifts in the geographic range of temperature forests and forest species as one response to global climate change. This study examines differences in tree-ring growth, and in the phenotypic plasticity of tree-ring growth in 16-year old white fir, Abies concolor, from ten populations grown in four common gardens in the Sierra Nevada of California. For each population tree-ring growth was modelled as a function of precipitation and degree-day sums. Tree-ring growth under these scenarios of doubled CO[sub 2] climates was estimated. Clinal variation in growth responses of white fir populations was found. Populations from cold sources were less plastic in their response to degree-day sums and populations from warm sources (typically lower elevation sites) were more plastic in their response to degree-day sums. Intermediate populations had intermediate responses. Differences between populations were more pronounced under the various warming scenarios than under current climatic conditions. Under the warmest climatic scenario, using output from UKMO, the growth response functions predicted that the most responsive population would grow at a rate 40% larger than the least responsive population. Population differentiation will affect forest productivity in the future and make more difficult the task of predicting the responses of forests to climate change. The substantial scientific uncertainties about the magnitude and rate of climate change and the responses of natural ecosystems to these changes makes formulating policy more difficult. This research indicates that a local phenomenon, population differentiation, may affect predictions of forest responses to climatic change, suggesting that further research may increase rather than decrease estimates of uncertainty about the effects of climate change. Policy responses to climate change will have to proceed in the face of such uncertainty.
- Research Organization:
- California Univ., Berkeley, CA (United States)
- OSTI ID:
- 7181244
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Response of tree growth to climatic variation and stand dynamics: Implications for modeling stand dynamics under varying climatic conditions
Abies concolor growth responses to vegatation changes following shrub removal, northern Sierra Nevada, California. Forest Service research paper (Final)
Related Subjects
CARBON DIOXIDE
ECOLOGICAL CONCENTRATION
CLIMATIC CHANGE
BIOLOGICAL EFFECTS
FIRS
BIOLOGICAL ADAPTATION
TREE RINGS
MATHEMATICAL MODELS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CONIFERS
OXIDES
OXYGEN COMPOUNDS
PINOPHYTA
PLANTS
TREES
560400* - Other Environmental Pollutant Effects
560300 - Chemicals Metabolism & Toxicology