Treesearch

The Bee Fire burned 9,620 acres of grass and chaparral in the San Bernardino National Forest in southern California from June 29 to July 2, 1996. Rate of spread data were determined from successive fire perimeters and compared with rate of spread predicted by the Rothermel rate of spread model using fuel model 4 (heavy brush) and a custom fuel model for chamise chaparral. A linear relationship between observed and predicted rate of spread was found (R2 = 0.60). The two fuel models performed similarly with only a difference in scale. Observed spread rates were approximately 80 percent of...

On Yap Island, indigenous management of the fallow in shifting agriculture has resulted in the development of site-stable taro patch and tree garden agroforestry systems. These systems are relatively sustainable and supportive of household economies , with some surplus for local market sales. however, a broad range of crops whose harvest is complementary to those produced in the agroforestry plots are still produced by shifting systems of agricultures in wild lands outside of villages. These are used to produced surpluses for special occasions. Althought traditional techniques for intensifi...

Tree health is a critical parameter for evaluating urban ecosystem health and sustainability. Tradi­tionally, this parameter has been derived from field surveys. We used multispectral remote sensing data and GIS techniques to determine tree health at the University of California, Davis. The study area (363 ha) contained 8,962 trees of 215 species. Tree health conditions were mapped for each physiognomic type at two scales: pixel and whole tree. At the pixel scale, each tree pixel within the tree crown was classified as either healthy or unhealthy based on vegetation index values. At the...

Communities in Western Washington and Oregon include nearly 7.4 million people (State of Washington 2001, US Census Bureau 2001) comprising almost 80% of the states’ total populations. The region’s rapid growth, development, and increasing congestion belie the area’s verdant repute. Forests continue to be a quintessential component of the Pacific Northwest’s economic, physical, and social fabric. However, with reliance on traditional forest products waning, urban and community forests bring opportunity for economic renewal, combating development woes, and increasing the quality of life for...

This paper presents a comparison of the structure, function, and value of street and park tree populations in two California cities. Trees provided net annual benefits valued at $ 2.2 million in Modesto and $805, 732 in Santa Monica. Benefit-cost ratios were 1.85:1 and 1.52:1 in Modesto and Santa Monica, respectively. Residents received $1.85 and $1.52 in annual benefits for every $1 invested in management. Aesthetic and other benefits accounted for 50% to 80% of total annual benefits, while expenditures for pruning accounted for about 50% of total annual costs. Although these results were...

Total canopy cover and canopy cover over street and sidewalk surfaces were estimated for street trees in Davis, California, U.S. Calculations were made using simple trigonometric equations based on the results of a sample inventory. Canopy cover from public trees over streets and sidewalks varied between 4% and 46% by city zone, averaging 14% citywide. Consideration of land use, planting locations, and age distribution suggests that 25% coverage of streets and sidewalks is an attainable goal for typical city zones.

The genus Cocos is monotypic. Cocos nucifera is believed to have originated in the Old World tropics, but the natural range is unknown and the origin of the species is the subject of considerable debate (Harries 1978, Parrotta 1993). Dispersal by humans has played a major role in the naturalization of the species on tropical and subtropical shores throughout the world.

Metrosideros is a genus of about 50 species. With the exception of one species found in South Africa, all grow in the Pacific from the Philippines, through Papua New Guinea, to New Zealand and on high volcanic islands (Wagner and others 1990). Five species occur in the Hawaiian Islands (Wagner and others 1990). Metrosideros polymorpha is native to Hawaii, where it grows on all the main islands except Niihau and Kahoolawe. It is the most abundant and widespread native tree in Hawaii (Adee and Conrad 1990) and grows in association with numerous species in both wet and relatively dry forests.

The genus Rhizophora comprises six to eight species and three or four hybrids (Duke 1992, Tomlinson 1986). All members of this pantropical genus are considered true mangroves and are limited in distribution to the intertidal zone. The native range of R. mangle includes the coast of central and southern Florida, Bermuda and most of the West Indies, both coasts of continental tropical America from Mexico south to Brazil and northern Peru, and the coast of West Africa from Senegal to Angola (Chapman 1976, Little and Wadsworth 1964). Rhizophora mangle has also been introduced in several other...

Acacia koa is one of three closely related species native to the Hawaiian Islands, where it is found on all the main islands except Niihau and Kahoolawe. It grows in almost pure stands, in mixed koa-ohia (Metrosideros polymorpha Gaudich.) stands, and in association with a variety of other tree species (Whitesell 1990).