共查询到20条相似文献，搜索用时 46 毫秒
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《林业科技开发》2001,(2)
甜柿优良品种及早实优质高产栽培技术该成果内容主要包括 :(1)收集 16 0多个柿属种质资源 ,建成我国南方第一个种质资源圃。 (2 )筛选出野柿 6号、1号两个优质砧木 ,解决了甜柿繁殖难关。 (3)采取配套先进栽培技术在立地条件较差的南方红壤低山丘陵地区引种 ,取得次郎品种早期丰产园 2年结果、3年投产、5年单产超过75 0 0ｋｇ/ｈｍ2 、7年单产达 1 5万ｋｇ/ｈｍ2 的良好成效。达到了早实丰产目标 ,从 2 0多个品种中筛选出适于我国栽培的 6个品种。 (4 )全面系统地开展了甜柿各品种的生物学特性研究 ,营养成分分析 ,果实发育过程中单宁、糖分… 相似文献
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根据农业部下达的“低丘红壤综合开发利用研究”合同项目,浙江省林科所与浙江省农科院土肥所合作,从1981年起在兰溪上华开展了“低丘红壤树种对比和造林技术的 相似文献
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甜柿苗真伪冬态鉴别技术 总被引：1，自引：0，他引：1
甜柿不需人工脱涩,采下即可食用,甜脆爽口,具有较高的营养价值和商品价值。近年来,全国甜柿生产空前高涨,许多省份大规模发展。由于目前我国苗木市场不规范,常有许多伪劣苗木充斥市场,如用涩柿冒充甜柿,劣质甜柿品种冒充优良主栽品种,大量的嫁接不亲和苗木混入其中,致使农民遭受巨大损失。于1994～1996年冬在中国林科院亚林所和浙江巨州苗圃地选择25个柿品种、砧苗木,每种100株以上,在室内对其形态特征进行详细的观察记载,并拍照和绘图,找出异同点,从苗茎色彩、皮孔、芽等表型形态上成功地区分了目前生产上常用和大量推广的多个甜柿品种,并… 相似文献
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红土丘陵毛竹丰产栽培技术的研究 总被引：1，自引：1，他引：1
金衢盆地的大片低丘红壤,由于土壤干燥瘠薄,限制了竹林的发展。农民用竹十分困难。为了促进农业生产的发展,活跃经济,逐步满足和改善人民日常生活和生产对竹产品的需要。我们于1971年至1972年,在浙江省兰溪县永昌乡永昌赵村进行红土丘陵种竹试验。 相似文献
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Opportunities for Small-Scale Forestry in Carbon Markets 总被引：2，自引：1，他引：1
This paper presents an explanatory framework of how greenhouse gas emissions offsets produced from natural and planted forests
(‘carbon forestry’) feature in voluntary and regulated carbon markets. An introduction to the convoluted policy malaise surrounding
the use of forests in regulated carbon markets is also presented. Whilst there are many opportunities and potential benefits
of using forests to produce offsets, relatively few carbon forestry projects currently exist, particularly in regulated carbon
markets. This seems due to financial, institutional and administrative obstacles, with prohibitive transaction costs often
cited as the most prominent constraint to expanded carbon forestry development. The papers in this special issue present a
wide coverage of carbon forestry development policy issues. The special issue provides a unique insight into the state of
carbon forestry globally and highlights the pressing need for policy and market reform to facilitate more sustainable carbon
forestry development. 相似文献
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The use of small-scale harvesting equipment continues to grow in forestry in many regions of the world. This equipment includes various devices and methods used to harvesting that generally are smaller, less expensive and less productive than advanced forestry machines. The objective of this study is to compare the efficiency of five alternative extraction methods implemented in a harvesting unit located in a mixed beech and oak forest ecosystem in northwestern Turkey. A continuous time study was conducted during primary transport operations that included skidding with animal power, skidding with farm tractor, hauling with farm tractor, hauling with forest tractor, and extraction by skyline. Timber was skidded uphill on a skid trail, and an average skidding distance of 100 m for all haulage methods was considered. Average slope of the harvesting unit ranged from 20 to 40 %. Average productivities for respective haulage methods were 3.80, 6.25, 2.80, 5.25 and 10.09 m3/h. Significant differences were found between productivity of haulage methods using one-way analysis of variance. The extraction by skyline, skidding with farm tractor, and hauling with forest tractor were determined to be the most statistically different methods, the productivity of these methods was found significantly higher than the other methods. Skid trails are useful for shortening distances during forest operations and skidding with farm tractor is a productive method in small-scale forestry of Turkey. 相似文献
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Forestland tenure institutions and patterns are in a period of rapid change in the USA. Historically dominant forestland tenures
are disappearing, and new tenures are emerging. Traditional, vertically integrated forest products firms have shed their forestland
holdings which have been picked up by Timber Investment Management Organizations (TIMOs) and Real Estate Investment Trusts
(REITs). Increasing numbers of private individuals and families are purchasing small rural tracts and some communities are
developing innovative means to gain control over nearby forestlands in order to protect these lands from commercial real estate
development. Within this context of rapid ownership change, small-scale forest owners including families and communities find
themselves at a competitive disadvantage, relative to large corporate owners, in wood commodity markets. This paper considers
how small-scale forest tenures, relative to large corporate tenures, may be advantageous to society with regard to selected
ecological, social, and economic factors. While the paper primarily draws upon illustrations from the US Pacific Northwest,
its themes are global in nature. 相似文献
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Small-Scale Timber Harvesting: Mule Logging in Hyrcanian Forest 总被引：1，自引：1，他引：0
Meghdad Jourgholami 《Small-Scale Forestry》2012,11(2):255-262
Animal-powered logging is a labour-intensive operation. Mule logging is still performed in the Hyrcanian forest ecoregion in Iran as a small-scale harvesting method. Mule logging in Namkhaneh district of Kheyrud Forest within this ecoregion was studied to develop hauling regression models and estimate haulage costs. A continuous time study was conducted of hauling of sawn-lumber, pulpwood and fuelwood, to assess mule logging productivity and cost for sawn-lumber and pulpwood as well as fuelwood hauling. Hauling distance was found to be the most important cost factor in wood extraction by mule. The hourly production rates of hauling with mule were 0.84, 0.52 and 0.42 m3 for sawn-lumber, pulpwood and fuelwood, respectively. The cost of the mule hauling system USD 13 per productive mule hours. Hourly costs of mule hauling of sawn-lumber, pulpwood and fuelwood logging were 15.5, 25, and 30.6 USD/m3. Increasing hauling distances caused a linear increase in haulage cost. There appears to be an opportunity to reduce cost of log production by increasing scheduled work hours, wider utilization of mules and reducing labour cost. 相似文献
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The small-scale harvesting equipment system has been and continues to grow in use in forestry operations in some regions in the world. This harvest system can include a range of equipment types, such as feller-bunchers or chainsaws, skidders or farm tractors, and chippers. These machines are generally smaller, lower cost and less productive than larger, more advanced forestry machines. The objective of this project was to investigate the feasibility of a small scale harvesting system that would produce feedstock for a biomass power plant. The system had to be cost competitive. A boom-type feller-buncher, a small grapple skidder and a chipper were tested as a small-scale system. In this study, feller-buncher and skidder productivity was determined to be 10.5 m3 per productive machine hour, and production for the chipper was determined to be 18 m3 per productive machine hour. Production from the system did not reach the desired levels of 4 loads/day (25 m3/load); however, the system was able to produce about 3 loads/day. The results showed that the system currently could fill a roadside van for $16.90/m3, but suggested machine modifications could potentially reduce the system cost to $12.73/m3. Residual stand damage was minimal, especially on flatter ground and not operating on a slash layer. Soil disturbance from the harvesting system was predominantly undisturbed or classified as a shallow disturbance. 相似文献
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Among other factors, harvesting intensity in private forests depends on property, resource and forest owner characteristics. The research was conducted in Slovenia, a Central European country with very fragmented and small-scale forest property, a large number of owners and co-owners and a long tradition of sustainable forest management. In the nationwide study, data from the Land and Property Register and forest inventory database were used to build a logistic regression model to identify factors that influence harvesting intensity. The results of the model revealed that growing stock, share of conifers, share of forest area under regeneration, total size of forest property in owner- and co-ownership, parcel size and accessibility of the forest area to forest operations increase harvesting intensity. Slope, number and age of owners and co-owners, and skidding distance negatively influence harvesting intensity. The results can offer useful information for policy and decision makers for formulating policy as well as implementing the most suitable mix of policy instruments. 相似文献
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《Journal of Sustainable Forestry》2013,32(4):61-80
Abstract Intensive, subsistence agriculture on hillsides of southeast Guatemala has caused extensive soil degradation. This retrospective study evaluated the success of an agroforestry treatment in improving the sustainability of mountainous agricultural systems in terms of soil nutrient status and erosion control. Three years after maize (Zea mays) and pasture fields were alley-cropped with N-fixing Gliricidia sepium trees, soil nutrient levels were examined and compared to nonalley-cropped controls. Agroforestry treatment showed significantly higher soil organic matter (SOM) over paired plots with no alley-cropping (mean 4.3% vs. 3.2% C, p < 0.05). Mean total N was also higher, with 0.12% in the nonagro-forestry control plots compared to 0.16% underthe agroforestry treatment (p <0.05). Some improvement in soil water-holding capacity(WHC) was also observed in the agroforestry systems. Differences in soil levels of available P, ranging from 8.0 to 64.4 μg/g, were not significant and correlated more with site than with agroforestry treatment versus control. Specific soil and site properties such as texture and slope as well as land use and ground cover management largely influenced improvements in soil nutrient status under the agroforestry treatment at each site. Despite increases in soil nutrients, maize plant productivity showed no response to the agroforestry treatment in terms of leaf chlorophyll index or maize plant height. Three years after the initiation of agroforestry, soil erosion rates showed no difference from paired controls; rates were correlated with ground cover and soil characteristics such as texture and surface rockiness rather than with agroforestry treatment. While soil nutrient status had not reached levels optimum for maize growth after three years, the positive trajectory of change in soil nutrients suggests the potential for using agroforestry systems in mountainous regions of Guatemala to increase the sustainability of agricultural production. 相似文献
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Tom Dedeurwaerdere 《Small-Scale Forestry》2009,8(2):193-209
This paper analyses the governance characteristics of an innovative policy instrument for sustainable forest management in Flanders, namely a mechanism based on social learning and collaborative planning within joint forest management organizations. These organizations have been successful in involving non-industrial private forest owners in managing the transition towards sustainable management in small-scale forestry. Why was this innovative scheme successful? And what are its shortcomings and possible limitations? The hypothesis developed in this paper is that the success of the forest groups has been made possible by the explicit organization of a process of social learning, leading to change in the beliefs and the social norms of forest owners and users. Based on the analysis of this case of cooperative forestry, and on theoretical insights from governance theory, the contribution to fostering social learning from three distinct mechanisms is established, these being (1) the recourse to sustainability criteria and indicators as an open-ended learning device, (2) the experimentation with disruptive action strategies to put new beliefs into practice, and (3) the building of new forms of social cooperation around these new beliefs and practices. 相似文献
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Under Vision 2020, a target was set in 1997 for trebling the forestry plantation area in Australia by the year 2020. Government subsidies and
extension for plantation establishment have largely disappeared, hence forestry expansion is highly dependent on access to
private finance. Plantation expansions throughout Australia has occurred predominantly through managed investment schemes,
and to a lesser extent by joint venture schemes between landholders and government or private enterprise. Relatively small-scale
hardwood plantations have been established, designed to replace the hardwood timber from the native forests that will be protected
from further logging after 2024 under the Regional Forestry Agreements. Views on financing methods for forestry expansion
in Queensland were investigated through by an email survey of 12 forestry and finance professionals, followed by in-depth
personal interviews of the same group of key informants. Issues identified include lack of transparent information, inequitable
taxation system between Managed Investment Scheme (MIS) companies and small-scale forest owners, need for further R&D on all
aspects of the industry, and design of a strategic alliance model for forestry investors. Participants took the view that
adoption of a strategic alliance model would encourage further investment in small-scale forestry and argued that this model
could protect the interests of all the stakeholders through reducing investment risk and creating competitive advantage. The
potential introduction of a carbon trading scheme also attracted interest from investors, who look for recognisable structures
that may alleviate the risk of investing in an industry with which they are unfamiliar. The participants considered that further
R&D should be the main focus for government participation in small-scale forestry, although recognizing current difficulties
with information sharing. 相似文献
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The authors tested two mini-yarders, one for uphill and the other for downhill extraction. The two machines were modern commercial
models, offering state-of-the-art yarding technology on a miniature scale and at a much lower cost than required for purchasing
a full-size tower yarder. The two units must not be regarded as alternative, but rather as complementary, since they offer
different capabilities and advantages. Both machines were tested while harvesting firewood from the thinning of young beech
stands in Central Italy. The tests indicated that both units can reach a productivity between 1.5 and 2.4 m3 SMH−1, including all delays, as well as set-up and dismantle time. Calculated extraction cost ranged between 24 and over 30€ m−3. The authors calculated a set of regression equations for estimating machine productivity as a function of the main work
conditions. The performance of the studied mini-yarders does not seem much inferior to that achieved by professional light
tower yarder under the same work conditions, but the lighter construction of the small-scale units may result in a lower resistance
to wear and abuse. In any case, mini-yarders seem ideal for deployment under the typical conditions of small-scale forestry,
offering a good solution to wood extraction on steep terrain, competitive with animal and winch logging in terms of productivity,
cost and operator comfort. 相似文献