Effects of the second-generation larch plantations onsoil fertility and tree growth

Larch is one of the most important plantation species in the northeast region of China. After clear cutting of larch plantations it is the urgent problem to besolved that whether the second generation is continuously plant6d, whether the soil fertility is decreasing and the plantstion is how to be managed onthe forestry produCtion. In odder tO realize the secondgenerahon Of larch plantstions and to provide thetheoretical base and the reasonable managementmeasures, we inventoried the groWth o…     

尖把梨盛果期低产园优质高产栽培技术

尖把梨风味浓郁,口感极佳,品质上等。因管理不当,导致盛果期树势过旺,树形紊乱,通透不良,产量品质低劣。经3年科学管理,各项指标明显改善,产量产值达到生产要求。栽培技术要点是,合理进行骨干枝改造,细致进行枝组枝条修剪,选择适合的授粉品种高接,适时适量疏果,有效防治病虫害和科学改土、施肥、灌水。     

不同类型沙松人工林产量及生长预测

文章对1963∽1964年在白石砬子自然保护区营造的沙松纯林、沙松-落叶松-阔叶混交林及沙松-阔叶混交林等不同林型人工林的固定标准地进行了产量观测，通过计算机拟合运算优化出指数函数Y=ae^bx，对各种类型沙松人工林进行了生长预测。结果表明，各类沙松人工林均有良好的发展前途，到55年生主伐时可获得可观的木材产量；除沙松-落叶松混交林外，其他几种混交林型材积生长量差异不显著；结合生态群落结构和生物多样性因素分析得出：在东部山区的适宜地区应大力推广培育沙松-落叶松-阔叶混交林等针阔混交林模式。     

Timber investment returns for selected plantations and native forests in South America and the Southern United States

Timber investment returns were estimated for the principal exotic and selected native species in the Southern Cone of Latin America and in the Southern United States. Exotic eucalyptus plantations in South America were most profitable, with internal rates of returns (IRRs) ranging from 13% to 23%, followed by exotic loblolly pine, with IRRs from 9% to 17%. Average loblolly pine plantation returns in the US South were less profitable, with an IRR of about 9.5%, and natural forest management in the South had IRRs of 4% to 8%. Subtropical native species plantations of the best araucaria and nothofagus species had reasonable financial returns, with IRRs ranging from 5% to 13%. Subtropical or tropical native forests had fewer commercial timber species, and had much lower growth rates and returns. Their IRRs were less than 4%, or even negative for unmanaged stands. State subsidy payments for forest plantations or for timber stand improvements increased IRRs somewhat and reserving areas for environmental protection reduced their IRRs slightly. Including land costs in the cash flows decreased these internal rates of return substantially. Natural stand returns in Latin America were much less than those of plantations, but management of those stands offered better rates of return than only holding the land.     

A review of management impacts on the soil productivity of South African commercial forestry plantations and the implications for multiple-rotation productivity

An overview of southern African research that has investigated the impact of management practices that can potentially affect the long-term site productivity of plantations is presented, with an emphasis of these impacts on soil productivity and with the implications for multiple-rotation site productivity. Activities that are most likely to cause long-term changes in soil productivity are identified as those causing high site disturbance during the inter-rotation period, notably ground-based mechanised operations and harvest residue management (including complete biomass removal) and, under some conditions, fertilisation. The impacts of these practices on soil and stand productivity are discussed from a southern African perspective. Knowledge gaps are identified and it is suggested that the immediate research priority is to identify meaningful indicators that are sensitive to change and that can be linked to stand production. Other key research focus areas are proposed and the need for a permanent long-term monitoring network is highlighted.     

意杨优质胶合板材的要求及其定向培育初探

淮阴是我国引种栽培意大利杨树最早的地区之一。其大径级优质材主要用于胶合板的生产。该文具体论核实 了意杨优质胶合板材的要求及其进行定培育的措施。     

Guiding Principles for Small-Scale Forestry in a Watershed of the Venezuelan Andes: Constraints and Opportunities

In the Venezuelan Andes, some small-scale forest plantations have become an important resource basis for forest management. In this paper, the forestry management progress in the Mucujún river watershed is analyzed. Constraints and opportunities for sustainable management within national policies, local regulations, environmental features and social benefits are also examined. Plantation assessment, and biophysical, legal and socioeconomics information, are used for guiding small-scale forestry practices in this watershed, with emphasis on the main principles of landscape management. These plantations have become an important part of the socio-ecological landscapes with potential for wood production—in the context of low intensity and low environmental impact environmental services and amenity—because of the two protected areas within the watershed. Current forest stand conditions, however, reflect that management requires improvement. Furthermore, the analysis suggests that improvement of local livelihoods may be achieved with a small-scale forestry approach, taking properly into account the basic criteria of social involvement and management of planted forests, while maintaining ecosystem services including biodiversity and water supply.     

东南沿海古树名木消亡规律与保护管理对策——以浙江省宁海县为例

通过对东南沿海古树名木保护管理的必要性及优劣势分析,以浙江省宁海县古树名木为例,对它们的消亡规律、保护管理的经验、存在的问题展开调查、分析、研究;并在此基础上,进行科学归纳,结合东南沿海的社会、地理、气候特点,制定出适合该地区的、切实可行的古树名木复壮技术措施和保护管理对策。