Regional growth changes in ozone-stressed ponderosa pine (Pinus ponderosa) in the Sierra Nevada, California, USA

摘要: Basal area growth trends were determined for ponderosa pine (Pinus ponderosa) in the Sierra Nevada, California, USA, to: (1) evaluate long term patterns, and (2) determine if there has been any recent change frequency of changes outside expected range natural variability. Ponderosa was sampled 56 stands with sample divided equally between sites without documentation symptomatic ozone injury. increment calculated, temporal patterns evaluated each tree using time series analysis techniques, summarized site by decade. There several regional during this century, including a large number decreases 1920s increases 1930s. Many synchronous within but less frequently stands. significant reductions since 1950 some southern Sierra. These growth...