Oaks ’n’ Folks – Volume 15, Issue 1 – March 2000 California’s oak savannas are home to many unique plants and animals. To the growing list of creatures for which oak woodlands are critical habitat, we’d like to add one
Read full articleA Half Century of Change
A Half Century of Change to the Flora of a Hardwood Rangeland in Northwest California Oaks ’n’ Folks – Volume 15, Issue 1 – March 2000 The 2,168 ha University of California Hopland Research and Extension Center (HREC) in southeastern
Read full articleHabitat Fragmentation Limits Pollen Availability
Habitat Fragmentation Limits Pollen Availability and Acorn Production in Blue Oak Oaks ’n’ Folks – Volume 15, Issue 1 – March 2000 Although the negative consequences of habitat fragmentation in forested landscapes are becoming better understood, we still know remarkably
Read full articleReturn of Natural Hardwood Regeneration in a Cleared Watershed
Many of California’s watersheds have been cleared of their tree and shrub cover, often with the goal of improving grazing conditions for livestock. Large areas of these watersheds can remain with few trees because several oak species are not regenerating adequately to replace removed trees. As a result, these watersheds are susceptible to soil erosion, diminished and degraded wildlife habitat, and decreased water quality.
Read full articleValley Oak Conservation
The valley oak (Quercus lobata) is one of California’s unique endemic tree species. It is distributed throughout the great Central Valley, in the coast ranges from Mendocino County south, and in the transverse mountains in southern California. Few examples of mature woodland exist in the Central Valley, where up to 90% of valley oak woodland has been cleared for agriculture and urban development.
Read full articleVernal Pools in Oak Woodlands
Vernal pools are seasonal bodies of water that form in shallow depressions following winter rains. Because of an underlying hard pan layer, water may persist for several months providing a wetland oasis for many uniquely adapted species of plants and animals. More prevalent taxa such as waterfowl, frogs, salamanders, dragonflies, and numerous aquatic insects readily use the pools for feeding, breeding, and juvenile development.
Read full articleAcorn Production by California Oaks
As one of the most abundant natural food resources in California, acorns provide food for a vast array of wildlife from scrub jays to mule deer and were formerly a staple of Native Californians, making up over half the diet of some groups and significantly influencing tribal ranges. Given their importance, it may seem strange that relatively little is known concerning acorn production patterns of California’s oaks.
Read full articleNutrient Cycling in California
A research project sponsored by the Integrated Hardwood Range Management Program examining nutrient cycling is showing that oak trees play a major role in maintaining the nutrient status of these ecosystems. Each year, a typical blue oak (Quercus douglasii) will return approximately 2, 1, 2.5, and 1.8 kg of nitrogen, phosphorus, calcium and potassium, respectively, to the soil surface in the form of litterfall (leaves, twigs and acorns) and canopy throughfall (canopy leaching).
Read full articleHistoric Distribution of Oaks from Pollen Analyses
A recent study funded by the IHRMP utilized pollen analysis to reconstruct the structure and abundance of oak woodlands in California on two different time scales: the late Quaternary period covering the last 15,000 years, and the last 500 years spanning the arrival of European settlers.
Read full articleA Hardwood Rangeland Classification System for California
An ecologically-based hardwood rangeland classification system for California provides private landowners, land managers, and researchers a unifying framework from which known ecological and management information can be retrieved. Standardization of type names facilitates the exchange of information on hardwood rangelands between and among agencies, landowners, and universities. As part of research funded by the Integrated Hardwood Range Management Program, dichotomous keys have been developed for the various type descriptions to ensure that the system is field oriented, and user-friendly.
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