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101.
R. Godoy 《Agroforestry Systems》1990,12(2):163-172
In this paper the author: (a) discusses the uniqueness of rattan among non-timber forest products, (b) examines the financial and the economic profitability of smallholder rattan cultivation, and (c) outlines a strategy for expanding smallholder rattan plantations among non-traditional producers. 相似文献
102.
103.
104.
105.
BudiadiEmail author Yoichi?Kanazawa Hiroaki?T.?Ishii M.?Sambas?Sabarnurdin Priyono?Suryanto 《Agroforestry Systems》2005,64(2):143-155
Kayu putih oil, extracted from the kayu putih tree (Melaleuca leucadendron), is an important non-timber forest product (NTFP)
in Indonesia. We compared productivity of kayu putih tree plantations among three different sites in East, Central, and West
Java, Indonesia. Leaf-twig, and branch production per tree differed significantly among the three sites. Tree biomass production
was highest at the site in West Java practicing tumpangsari (a form of shifting cultivation) of kayu putih with rice (Oryza
sativa) on alluvial soils. Tree biomass production was lowest at the site in East Java, practicing tumpangsari of kayu putih
with maize (Zea mays) and cassava (Mani- hot esculenta). At this site, tree biomass production increased with increasing stand
age and low production was compensated by greater biomass yield of companion crops. Intermediate tree biomass production was
observed at the site in Central Java where intercropping is only practiced for the first two years after plantation establishment.
Production of tree biomass and kayu putih oil did not increase with increasing stand density, indicating that at a given site,
high tree stocking did not lead to high production. Stand-level productivity of the plantations increased with increasing
stand age and maximum productivity was attained at 15 to 35 years, after which productivity declined. This suggested unsustainable
stand productivity as plantations increase in age. 相似文献
106.
Yanjie Hu John Perez-Garcia Alicia Robbins Ying Liu Fei Liu 《Scandinavian Journal of Forest Research》2015,30(1):13-29
Over the last decade, while the size of China's economy more than doubled, China has simultaneously become a major producer and exporter of forest products. Although China's domestic supply of wood is significantly constrained both by a limited natural supply and by conservation-oriented policies, the country is increasingly regarded as the world's “wood workshop.” Furthermore, China is the largest driver of demand for the trade in tropical logs and is becoming a significant driver of demand for trade in coniferous logs. In this paper, we describe a spatial equilibrium model adapted to study forest sector markets and policies that affect them. We present the model and the result of two alternative future scenarios. The first scenario analyzes the impact on global forest products markets of a US recovery in wood markets. The second scenario examines the effect on global forest products markets of decelerating growth in Chinese demand for wood products. Through these two scenarios, the modeling output sheds light on the role China's wood products markets have on resource supply and trade around the world. The trade model shows substantial potential changes in global prices, production, and trade activity associated with the recovery in domestic demand in the USA. 相似文献
107.
Since its inception nearly 15 years ago, environmental certification has become an important issue in the wood products industry. One research question that has been examined is the potential willingness for supply chain participants to pay a premium for certified products or raw materials to offset certification costs. This study examines stated willingness to pay for four wood products from the perspective of U.S. consumers. Data was collected in 1995 and 2005 from the population of U.S. residential consumers to detect changes in willingness to pay for certified wood products along time and increase the statistical strength of the model. Results of an ordered probit model suggest that higher probabilities of paying a premium are associated to consumers who seek out certified products and who believe certification can lessen environmental impacts such as tropical deforestation. There is also a strong relationship between respondent income and willingness-to-pay. Despite the current industry structure in the U.S. that has adopted a mass-certification strategy that does not place price premiums on certified products, results suggest that such premiums may exist for imported certified tropical wood products. Analysis of marginal effects suggests consumers' willingness to pay a 10% premium for three of the four certified items studied. Niche markets may potentially be exploited in the U.S. and price premiums captured by wood products manufacturers in tropical regions and/or American importers. 相似文献
108.
Nontimber forest product harvesting in the Pacific Northwest is neither a new activity nor a disappearing relic of the pre-industrial era. Though the emphasis may have shifted from subsistence to commercial and recreational pursuits, harvesting and harvesters of wild species are still widespread throughout the region. Hundreds of businesses and thousands of harvesters earn part or all of their income from the harvests. Every year thousands of pounds and hundreds of nontimber forest products valued in the hundreds of millions of dollars are harvested from regional public and private forests. This harvesting of a large diversity of species represents a considerable subset of the overall terrestrial biodiversity in Pacific Northwest forests. Despite widespread extraction, little investment in research, planning, or basic inventorying and monitoring has been done on nontimber forest products. Without better information, land managers will be increasingly unable to make informed decisions on how to manage nontimber forest product biodiversity sustainably as demand for products increases. 相似文献
109.
The embedment tests of laminated veneer lumber (LVL) with two moduli of elasticity (MOE; 7.8 GPa and 9.8GPa), parallel strand lumber (PSL), and laminated strand lumber (LSL) were conducted in accordance with ASTM-D 5764. The load-embedment relation for each of these engineered wood products (EWPs) was established. The directional characteristics of bearing strength (e), initial stiffness (k
e), and effective elastic foundation depth were obtained from the tested results. The effective elastic foundation depth (=E/k
e,E = MOE), based on the theory of a beam on elastic foundation, was obtained from thek
e and MOE. An of 90° (perpendicular to the grain) was calculated by dividingE
90 [MOE of 90° from the compression test, but MOE of 0° (E
0), parallel to the grain, obtained from the bending test] byk
e90, the initial stiffness of 90°. This study aimed to obtain the bearing characteristics of each EWP, taking into consideration their anisotropic structures, for estimating the fastening strength of a dowel-type fastener. The relations between the bearing coefficients (
e,k
e,) on the loading direction and dowel diameter were established from the load-embedment curves. Based on the results of the embedment test, tested EWPs showed different tendencies in all directions from wood and glued laminated timber.Part of this study was presented at the 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999 相似文献
110.
本试验旨在应用间接竞争酶联免疫吸附测定(ELISA)法以及色谱法测定不同加工工艺的大豆饲料产品中主要大豆抗营养因子大豆球蛋白、β-伴大豆球蛋白和胰蛋白酶抑制因子以及大豆中蔗糖、棉子糖和水苏糖的含量。采用ELISA试剂盒对国内257份大豆制品中大豆球蛋白、β-伴大豆球蛋白和胰蛋白酶抑制因子含量进行检测与分析;利用离子色谱建立了大豆产品中蔗糖、棉子糖和水苏糖的灵敏、准确的同步测定法,并对国内92份大豆制品中寡糖含量进行检测与分析。结果表明:发酵豆粕、膨化大豆、大豆浓缩蛋白和大豆分离蛋白中大豆球蛋白、β-伴大豆球蛋白和胰蛋白酶抑制因子含量相对较低;本试验所建立的离子色谱同步测定大豆中蔗糖、棉子糖和水苏糖的方法具有灵敏度和准确性高、重现性好的优点,适用于大豆寡糖的测定;通过对实际样品的检测和分析,发现发酵豆粕和大豆分离蛋白中3种大豆寡糖含量均相对较低。本试验所得到不同加工工艺的大豆产品中主要抗营养因子含量的相关数据将为大豆在畜禽饲料中的高效利用提供很好的技术支撑。 相似文献