Treesearch

A total of 62 coast live oaks (Quercus agrifolia) were monitored since they were initially boxed for transplantation in 1993. At that time, only branches injured during the moving process and deadwood were removed, leaving the entire canopy intact. This was a departure from the usual transplanting methodology that traditionally removes up to 70 percent of the canopy in order to compensate for the massive root loss incurred during boxing. To date, survival of non-pruned trees has exceeded that of a cohort of 25 transplanted oaks that received the standard canopy reduction. A discussion of...

Knowledge of relationships among plant communities and environmental variables can be used in restoration, ecological assessments, predictive mapping and conservation planning. This information would be particularly important in the conservation of endangered ecosystems, such as those of Garry oak in British Columbia. To investigate relationships, sixteen environmental variables were examined for a plant community framework using Detrended Correspondence Analysis and interpretive graphing. Overall, the variables and the degree of differentiation were adequately represented by the framework...

A new canker disease of Lithocarpus densiflorus, Quercus agrifolia, Q. kellogii, and Q. parvula var. shrevei in California is shown to be caused by Phytophthora ramorum. The pathogen is a recently described species that was previously known only from Germany and The Netherlands on Rhododendron and Viburnum. This disease has reached epidemic proportions in mixed evergreen and redwood forests over an area approximately 300 km long along the central coast of California. The most consistent and diagnostic symptoms on larger trees are the cankers that develop before foliage symptoms become...

Rapid urbanization of California's oak woodlands is having a pronounced effect on its ecological values. These areas are sought out for new residential sites to a large degree because of their amenity values. In response to this rapid exurban migration, there has been an increase in use of conservation easements and purchase of development rights by land trusts and other entities to maintain large blocks of open space. However, the effect of dedicated open space on land markets is not known. This project is designed to quantify how aesthetic and environmental values of adjacent oak...

Blue oaks (Quercus douglasii) are not regenerating well over much of California. The roles of fire and browsing in regeneration are probably significant, but poorly understood. We burned two foothill blue oak woodland sites which contained significant numbers of small trees between 40 and 70 cm tall, then compared height growth over 14 years among 48 trees that were: a) unburned and unbrowsed, b) unburned but browsed, c) burned and browsed, and d) burned and unbrowsed. Fire completely killed and/or removed the tops, but all plants subsequently resprouted, creating an even-aged stem class....

Garry oak (Quercus garryana) meadows of the Pacific Northwest are heavily invaded but the dynamics surrounding this ecosystem transformation are poorly understood. Of particular uncertainty is the role of the invasive species in structuring the community, and the potential stability of this invasive-dominated system when disturbed. Clarifying such issues is central to restoration success for Garry oak meadows, one of Canada’s most endangered terrestrial ecosystems. This paper examines the competitive inter-relationships among exotic and native flora, and how these inter-relationships are...

Use of prescribed fire for management of livestock forage and fuel load is increasing in California oak woodlands, but its effects on vertebrate wildlife are unknown. We conducted a light-intensity prescribed fire in mixed blue oak-coast live-oak woodlands in coastal-central California and assessed vegetation change and numerical response of small, non-game vertebrates, to the fire. The prescribed fire significantly reduced four (grass, shrub cover, coarse woody debris, woodrat houses; P

The Santa Barbara County Oak Restoration Program was initiated in 1994 to determine the major factors limiting recruitment of valley oak (Quercus lobata) and coast live oak (Q. agrifolia). At Sedgwick Reserve in Santa Barbara County, California, we have replicated large-scale planting experiments in four different years to determine the effects of cattle and other ecological factors on oak seedling establishment in oak savannas and woodlands. In 33 large experimental plots (50 x 50 m) we planted acorns collected from Q. lobata and Q. agrifolia on the site. Fifteen of these large plots are...

The Oak Habitat Restoration Project began in 1991 when several individuals recognized that the oak woodlands and savannas of Walnut Creek's nearly 2,800 acres of open spaces had little natural regeneration. This group gathered volunteers who harvested acorns, planted them, and then installed tree shelters and watered the resulting seedlings. The Project soon became a unit of the Walnut Creek Open Space Foundation, which now provides most of our equipment and materials. The Project usually has 18 activity dates each year, nearly all on Saturday mornings. We usually plant 250 to 300 sites...

Resource agencies, private landowners, and citizen monitoring programs utilize turbidity (water clarity) measurements as a water quality indicator for total suspended solids (TSS – mass of solids per unit volume) and other constituents in streams and rivers. The dynamics and relationships between turbidity and TSS are functions of watershed-specific factors and temporal trends within storms and across seasons. This paper describes these relationships using four years of water quality and stream discharge data from seven experimental watersheds in the northern Sierra foothills and north...