Treesearch

The symposium, held at San Diego State University, provided information about the Mediterranean-type ecosystems found throughout the world. In the papers, and in brief summeries of poster displays, both researchers and managers addressed concerns relating to vegetation, fauna, soils, hydrology, fire, and planning. A Review and Follow-up section presents general comments of selected participants.

The California Wildlife/Fish Habitat Relationships (WFHR) System is an ongoing effort to apply our knowledge of wildlife habitat requirements to identify and explain the consequences of proposed land use activities, particularly those activities that affect vegetation. The U.S. Forest Service initiated the WFHR program in California in 1976 and has developed it for all Forest Service lands in the state. The California Department of Fish and Game is currently expanding the WFHR program to include non-Forest Service lands in California.

A taxonomic Vegetation Classification System proposed for use in California is designed to simplify interdisciplinary communication about vegetation. The system structure is an aggregative plant community hierarchy at four levels of precision--the Association, Series, Subformation, and Formation. A flexible Phase category links specific resource management concerns to the system. The System is based on the concept of vegetation as an ecological component, and is neutral with respect to management function; design criteria stem from performance needs and principals of classification. The...

In analyzing fire management programs for their economic efficiency, it is necessary to assign monetary values to the changes in resource outputs caused by, fire. The derivation of resource values is complicated by imperfect or nonexistent commercial market structures. The valuation concept recommended for fire program analyses is willingness-to-pay because it permits uniform derivation of resource values across all resource categories, and it represents the full economic value of the output to society. The process of measuring fire effects in program evaluations introduces implications...

On fuelbreaks, herbicides have been the primary tool for controlling brush regrowth. Vegetation of low volume and low growth is maintained on these wide strips as an aid to firefighting safety. Goats are a promising alternative to herbicides, and may be the best tool available for controlling brush regrowth on fuelbreaks. They eat a wider variety of plants, and more woody plants, than other livestock. They are less selective on first-year brush regrowth, and more selective as brush is older. Goats should not be expected to control tall, mature brush. A good strategy is sufficient goats to...

This manual describes fast, low-cost biochemical procedures for separating enzymes representing numerous genes of forest trees. During electrophoresis the mixture of enzymes from a megagametophyte or embryo of a germinated seed separates in a gel. Specific stains applied to gel slices locate each enzyme. These procedures expand on those developed for crops research. They provide a means for forest geneticists to get urgently needed information on the amount and geographic distribution of genetic variation in conifers for evaluating species relationships, for protecting rare natural...

Natural pyrethrins and nonhalogenated synthetic pyrethroids are highly active and safe insecticides but are not photostable. A stabilized formulation was developed based on 1% of mixed diarly-p-phenylenediamines in an aromatic solvent. The synthetic pyrethroids bioethanomethrin and resmethrin as well as natural pyrethrins were protected from degradation when exposed to artificial and solar radiation. The photostabilization effect was also confirmed by bioassay against the western spruce budworm.

Fourth-instar larch casebearer, Coleophora laricella (Hübner), was significantly less susceptible to acephate and malathion than were adults of its parasites. Chrysocharis larcinellae(Ratz.) and Dicladocerus nearcticus Yoshimoto (P0.01) than the hosts to diflubenzuron. Malathion was equally toxic to both parasite species. D.nearcticus appeared to be the more tolerant of the parasites to both acephate and diflubenzuron.