Treesearch

Oak trees in California are subject to periodic burning by fire, but their trunks and crowns vary in tolerance to fire. And once burned, oaks are difficult to identify by species. Fifteen oak species grow in California. This report provides keys to identifying five species of southern California oaks: coast live oak (Quercus agrifolia Née), interior live oak (Q. wislizenii A. DC.), California black oak (Q. kelloggii Newb.), canyon live oak (Q. chrysolepis Liebm.), and California scrub oak (Q. dumosa Nutt.). For each species, the characteristics of leaves, acorns, and bark; response to...

Abundance, survival, and growth ofmamane (Sophora chrysophylla) regeneration were determined inside and outside sheep exclosures located in heavily browsed portions of the mamane forest of Mauna Kea, Hawaii. Vegetational cover of other species was estimated. Mamane grew abundantly inside 16-year-old exclosures but was sparse outside. Height class distributions indicated that feral sheep prevented establishment of regeneration. Survival of seedlings and sprouts at 2-year-old exclosures was greater inside than outside. The largest difference between survival inside and outside was found...

Using aerial photographs taken in 1954, 1965, and 1975, percentage of tree cover was determined for three sections of the sheep- and cattle-grazed mamane (Sophora chrysophylla) forest of Mauna Kea, Hawaii. In one section, the Ka 'ohe Game Management Area, where grazing by sheep was judged light, tree cover increased slightly during the 21-yr period, and tree cover did not change significantly along an elevation gradient. This condition was probably the result of the predominance of naio (Myoporum sandwicense) trees, which are not as palatable as mamane and, therefore, are less sensitive to...

Management of feral and Mouflon sheep and feral goats within the Mauna Kea Forest Reserve/Game Management area has been criticized as inadequate to prevent the adverse environmental impact which these introduced herbivores have on native components of the scrub forest ecosystem. This study determined the intensity of bark stripping of mamane (Sophora chrysophylla), a small endemic leguminous tree, by these animals and assessed the impact of their browsing on the size class structure of mamane stands. In all but one of the 4 areas sampled, a high proportion of mamane trees bore bark...

A trial planting to compare the biomass production of 9 tree species was established in May 1979. Species compared were Acacia melanoxylon, Casuarina cunninghamiana, Casuarina equisitifolia, Eucalyptus camaldulensis, E. dalrympleana, E. regnans, Populus hybrid, and Taxodium distichum. E. globulus was substituted for E. regnans when the latter failed to survive. E. camaldulensis and E. dalrympleana were superior to all other species. Other commercial plantings have been established in the intermediate and interior valleys of Riverside and San Diego Counties. Eucalyptus species included in...

The Soil Conservation Service is in the early stages of testing many species of Eucalyptus or windbreaks. Over 260 different species have been collected. The pre-planting selection criteria and process is described as well as the test conditions and procedures. Some sources of information on the use of the Eucalypts may be misleading through overgeneralization. Early results support the need for greater communication and testing of a wide variety of species and provenances in California.

California was settled in an era before the full impact of the industrial revolution that was taking place in Great Britain was fully realized, a revolution that was to change the course of western culture more drastically than any previous time in history. Friedrich Engels wrote in 1845 of the industrial revolution as "a revolution which at the same time changed the whole of civil society, and the significance of which for the history of the world is only now beginning to be understood" (Tucker 1972). Society of today tends to forget the needs of the historic peoples before machinery,...

To provide up-to-date information on Eucalyptus in California, researchers from Califor-nia, Florida, Hawaii, Oregon, and France presented papers on species selection, products, uses, and economics, growth and yield, cultural requirements, propagation, and breeding programs. This Proceedings of the Workshop should serve as a useful reference for landowners, foresters, nurserymen, horticulturists, and others who are planning to plant Eucalyptus.

Recent reviews have suggested that tree species are the most variable of organisms, as measured by proportion of polymorphic loci or average heterozygosity (Hamrick, 1979; Hamrick et al., 1979). Average heterozygosity is greater than 0.30 for several conifers. By contrast, annual herbaceous species have a mean heterozygosity of 0.13 (Hamrick et al., 1979).