Treesearch

Oak woodlands, the predominant vegetation type in the most inhabitable areas of California, comprise 10 million acres in the State and have been used primarily for livestock production. Today, residential intrusion into oak woodlands results in habitat fragmentation and degradation of economic, esthetic, and ecological values. Decision makers must face up to the population pressures caused by the increasing human population in California and its shift from coastal metropolitan areas into formerly rural areas—especially oak woodlands. Newcomers want roads, schools, housing, shopping...

ABSTRACT. We compared stomatal conductance, transpiration, plant water potential, and soil moisture depletion patterns for three shrub species common on early seral forest sites in southwestern Oregon following logging or fire. Our goal was to determine which of these species were more likely to be the strongest competitors with regenerating conifers. The three species, Arctostaphylos patula Greene, Ceanothus sanguineus Pursh., and Holodiscus discolor (Pursh.) Maxim., were selected to represent a range in leaf morphology and expected water use patterns. Diurnal patterns of leaf conductance,...

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Summer throughfall and year-round precipitation chemistry were studied for three years at Barton Flats (BF), a low to moderate pollution site in the San Bernardino Mountains (SBM) in southern California. Winter fog plus dry deposition, and bulk deposition were also measured during one season at three sites traversing an atmospheric deposition gradient in the SBM. Throughfall N (NO3- + NH4+) inputs during the growing season in 1993 were 4.0 kg ha-1 compared to 0.4 kg ha-1 for S. Deposition of N and S in summer 1994 was 50% of that in 1993, and precipitation in summer 1994 was 31% as high as...

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