Treesearch

Douglas-firs from 91 seed sources in North America were evaluated after 5 and 6 years in 15 common-garden tests in the mountainous regions of northwest and north central Spain. Analyses of tallest trees showed that most of the sources of highest potential for reforestation in Spain are found in regions where the Pacific Ocean air mass dominates climate. Fast growers came from coastal slopes of the Coast Ranges from northwest California to the Georgia Strait of southwest British Columbia and inland slopes of the Olympic Mountains and Coast and Cascade Ranges facing the Puget Trough in...

SYSTUM-1 is an individual-tree/distance-independent simulator developed for use in young plantations in California and southern Oregon. The program was developed to run under the DOS operating system and requires DOS 3.0 or higher running on an 8086 or higher processor. The simulator is designed to provide a link with existing PC-based simulators (CACTOS and ORGANON) currently in use in northern California and southern Oregon. The input requirements include a sample of trees including heights, species, and expansion factor as well as a sample of competing vegetation including percent cover...

This paper summarizes a longer presentation of research needs identified by two working groups commissioned by the Land Grant Colleges of the Pacific. Major discussion points by the workshop participants are also summarized.

Long-term research into the composition, phenology, yield, and growth rates of agroforests can be accomplished with the use of permanent field plots. The periodic remeasurement of these plots provides researchers a quantitative measure of what changes occur over time in indigenous agroforestry systems.

Procedures and methods used to determine the structure of an agroforest are presented. Simple statistical procedures to present the data in a meaningful form are also discussed.

Agroforestry has the potential to contribute greatly to Pacific island development efforts. However, success will depend on fully realizing the social implications of agricultural research on island cultures. Agroforesters must recognize their role as "agents of change." Because of this, they must strive for the involvement of the community in all stages of their research. The applied research approach, exemplified by the Farming Systems Research and Development methodology, is offered as a model approach.

Statistical topics that related to agroforestry studies are discussed. These included study objectives, populations of interest, sampling schemes, sample sizes, estimation vs. hypothesis testing, and P-values. In addition, a relatively new and very much improved histogram display is described.

The concept of sustainability is an underlying theme in much of the literature dealing with the economics of agroforestry. Four major areas of concern for economic investigation into sustainable agroforestry systems — profitability, dynamics, externalities, and markets — are addressed using examples from the available literature. Finally, the social constraints that farmers face when adopting agroforestry technologies are discussed.

For the many Micronesian islands, agroforestry was a sustainable land use system, and an integral component of the traditional subsistence system which provided the people with many of the necessities of life. Given the increasing pressures on limited land resources, the social and environmental problems associated with modern agriculture, particularly its use of pesticides and fertilizers, greater attention is being paid to agroforestry as a low-input sustainable agricultural system, appropriate to Micronesia and the rest of the Pacific. Unfortunately, relatively little detailed informatio...

The indigenous agroforestry system on Pohnpei was studied using circular plots laid out in transect across 57 randomly-selected farms. Data were collected on species and cultivar presence, size, density, frequency, as well as soil type, slope, aspect, and other related information. Through farmer interviews, farm family demographic data was also recorded. Seasonality of major crops was observed. Analysis shows indigenous agroforestry on Pohnpei to be a complex, but extremely well ecologically and culturally adapted, production system.