首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4篇
  免费   0篇
林业   3篇
畜牧兽医   1篇
  2017年   1篇
  2012年   1篇
  2006年   1篇
  2005年   1篇
排序方式: 共有4条查询结果,搜索用时 0 毫秒
1
1.
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   
2.
We investigated age-related changes in biomass cycling and soil properties in a kayu putih (Melaleuca leucadendron LINN, Myrtaceae) with improved shifting cultivation system in East Java, Indonesia, to design better management plans for sustainable kayu putih oil production and crop yield. Harvested biomass of kayu putih increased markedly from 7- to 15-year-old stands, but did not increase further in older stands averaging 2.41 Mg ha−1 yr−1. Kayu putih contributed 1.9–31.0% of total biomass production. Cassava (Manihot esculenta Crantz) tuber was the largest component of biomass cycling. Harvested biomass of cassava decreased with increasing stand age and there was a trade-off between above- and below-ground biomass productions. Harvested biomass of maize (Zea mays L.) grain was constant throughout stand growth, whereas returned biomass fluctuated. With increasing stand age, soil organic matter (SOM) accumulated in soil indicating that returned biomass was decomposing slowly. Content of primary nutrients did not change with stand age. The contribution of cassava to harvested biomass was considerably larger than that of kayu putih. For this reason, selection of cassava as a single companion crop may not be suitable for sustaining kayu putih oil production. Maize may be a good companion crop for kayu putih because it produces a constant grain yield throughout stand growth and its contribution to harvested biomass is comparable to that of kayu putih. In addition, maize is shallow-rooted and causes less below-ground competition with deep-rooted kayu putih trees.  相似文献   
3.
4.
Smallholder timber plantations may offer opportunities for farmers to increase their income. Nonetheless, such opportunities are often lost largely due to unfavorable regulations imposed on harvesting and marketing of timber. Adverse impacts are worsened because the regulations are not effectively communicated to smallholder farmers. We assessed the level of smallholder knowledge of existing regulations and found it very low. In part, this correlated to their socio-demographic characteristics. Poor literacy skills and a low level of education make it difficult for older farmers’ to increase their knowledge. This is compounded by the limited information channels that can reach the farmers. Improving smallholders’ knowledge by providing information concerning markets and regulations in a timely and clear manner could help smallholders exercise coping strategies and priorities when selling their timber that would in turn reduce the negative impacts of regulations. The roles of village authorities could be crucial. They are close to the smallholders and could channel the information. The government could provide training and incentives for them to be more active in communicating the regulations to the smallholders.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号