Treesearch

Tree mortality caused by root diseases constitutes a major drain on Forest productivity of mixed-conifer stands. Factors such as changes in species composition, selective harvesting, unfavorable economic climate, and optimizing of short-term benefits have contributed to current stand conditions. Computer simulation models, such as the "RRMOD Computerized Root Disease Simulation Model", are currently available to managers to evaluate the effects of stand management under different silvicultural prescriptions. Several management strategies are available to managers to reduce losses caused by...

This paper describes specific measures recently employed for protection of riparian resources during construction of an oil and gas pipeline that crossed coastal reaches of 23 perennial and intermittent streams between Point Conception and Gaviota in Santa Barbara County, California. Flumes were constructed to maintain stream flow; anchored straw bales and silt fences were used to filter sediment in the streams; water bars, incorporated straw mulch, anchored jute fabric, and trench plugs were installed to minimize soil loss on slopes; jute and synthetic fabrics were used to stabilize...

This analysis will consider Riparian benefits from alternative project designs at Wildcat and San Pablo Creeks. Particular emphasis will be placed on quantification of riparian values and on the relationship of projects benefits for each project alternative to estimated costs of implementation.

Abstract - Large floods in northwestern California in the past two decades have mobilized extensive areas of valley floors, removed streamside trees, and widened channels. Channel cross sections were surveyed to illustrate an hypothesis on the linkage between sediment transport, colonization of channel margins by trees, and streambank recovery. Riparian trees, e.g., white alder (Alnus rhombifolia), colonize the water's edge at low flow to receive adequate moisture during the dry season. Such stands can endure annual high flows only after the flood-enhanced sediment load declines and the...

In order to successfully combat pathogens such as annosus root rot, the land manager and pathologist must have periodic dialogue about the pest, its identification, effects, impacts, and cures. The author presents four important topics to structure this dialogue. These are (1) training from the pathologist to the silviculturist or other land manager, (2) site specific input, by the pathologist to silvicultural prescriptions, (3) risk assessment models, and (4) marginal analysis models.

Active management of coastal streams is needed to ensure the continued existence of significant riparian systems in Southern California. The concept of a dynamic self-replacing plant community is no longer a truism there. In the past decades one exotic species in particular, the Giant Reed (Arundo donax L.) has had an ever-increasing negative role in the succession of riparian systems. The aggressiveness of this exotic has enabled it to invade disturbed areas along many water-courses of Southern California. Giant Reed is also capable of invading mature woodlands, interrupting the cycle of...

A cumulative watershed effect (CWE) is any response to multiple land-use activities that is caused by, or results in, altered watershed function. The CWE issue is politically defined, as is the significance of particular impacts. But the processes generating CWEs are the traditional focus of geomorphology and ecology, and have thus been studied for decades. The CWE issue is complicated by the variety of land-use activities which cause impacts, and by the multitude of philosophical and economic values impacted.

In 1984 – 1987 the recovery of riparian willows (Salix spp.) and sycamores (Platanus racemosa) was studied on two short, intermittent stream sections in a newly acquired portion of Henry W. Coe State Park in central California. Prior to removal of cattle in 1983, the plots contained mature sycamores, one young sycamore, and five willows. By 1985 over 320 willows, 16 sycamores and 1 cottonwood (Populus fremontii) had appeared, and basal sprouts had developed on the mature sycamores. Young willows and sycamores grew slowly, and establishment and growth generally ceased as surface flows...

Protecting riparian habitat from livestock grazing on private land is a complex task that requires paying attention to sociological and economic as well as physical and biological factors. Six livestock exclusion fencing projects on private property in northwestern California are described. The importance of long term maintenance and the need for landowner incentives are discussed. Significant gains may be made via a statewide, coordinated effort to encourage the protection of riparian habitat on private property.