林改后农户林业经营效率的影响因素分析——基于DEA-Tobit分析法的实证研究

基于福建省南平、龙岩、三明等地的问卷调查,运用DEA-Tobit模型对农户林业经营效率的影响因素进行实证分析.研究发现,户主年龄、户主受教育程度、林地块数、林地离公路的距离、林地坡度、经营类型、经营主体类型、种苗质量、施肥次数、整地方式、林业收入占家庭收入的比重、资金来源渠道的畅通性、伐区调查设计制度、林业税费等14个因素对林业经营效率影响显著.因此,提升林农的林业经营水平与变革林改配套措施是可行之策.     

著名环境作家徐刚力作——大地工程——内蒙古田野调查(连载二)

直接从退耕还林中受益的农民,已经由“要我退”成为“我要退”。在造林前普遍进行的必须要达到高标准的“水平沟”整地中, 习惯于在黄土丘陵上粗放耕作的农民,学会了在黄土地上的精雕细刻,并且告诉我:“这水平沟就是树娃娃的摇篮,可以挡风还能够拦截地表水,这叫蓄水保墒,根深叶茂。”和林的“水平沟”2．4     

数字

1600万亩我国森林面积从1999年到2011年完成了退耕还林4.34亿亩。"十二五"期间,我国拟在川、渝、鄂等长江中上游重点水源区,黔、桂、滇等喀斯特石     

退耕还林与农业可持续发展

文章立足青海农业资源现状和退耕还林规划实施情况，分析了退耕还林对农业可持续发展的意义，简析了影响退耕还林的不利因素。     

ArcGIS技术在县域退耕还林决策分析中的运用——以江西省于都县为例

运用ArcGIS技术,结合江西省于都县耕地的数量与空间分布状况、坡度、人口等因素对该县退耕还林工作进行辅助决策分析,深入分析到乡镇以确定该县退耕还林区和退耕还林的实施措施,为于都县的退耕还林决策工作提供科学参考。     

对实施退耕还林（草）试点工作的调查与建议

对湟中县退耕还林（草）示范试点工作实施情况进行调查,提出了坚持4个原则、突出3个重点、做到5个到位。存在的问题：林灌工程不配套、管护费未列入工程预算之内。并提出了加强农田林地灌溉配套设施建设、提高苗木补助标准、制定林木管护的政策法规、建立种苗基地等建议。     

退耕还林工程不会影响我国粮食安全

针对近期一些部门、专家关于“粮食减产主要原因是退耕还林造成的”看法,国务院西部地区开发领导小组办公室副主任王志宝认为,这种认识是片面和不正确的,不能简单地把退耕还林与粮食减产划等号,退耕还林工程更不会对我国粮食安全造成影响。王志宝指出,由于全国粮食产量连续 4 年减产,库存急剧下降,粮食供求关系发生了变化。当前的问题是如何正确分析和认识我国粮食减产的主要原因,并有针对性地采取措施。对这一重大问题,必须采取客观、全面、实事求是的科学态度。他说,今年,国家统计局农调队就退耕还林对全国粮食生产的影响进行了跟踪调…     

平安县退耕还林工程实施情况与后续政策的思考

平安县是国定贫困县,近年来在退耕还林工程建设上取得了明显的成效。文章对平安县实施退耕还林政策后取得的收益进行了分析,指出了存在的问题,在此基础上就后续政策方面提出了建议。     

干旱河谷区退耕还林的意义与效益 ——以阿坝州小金县为例

在生态考察和资料调研的基础上 ,以阿坝州小金县为例 ,探讨了四川省干旱河谷区退耕还林的思路及效益 ,认为退耕还林对于干旱河谷区、生态脆弱区、旅游资源丰富地区具有重大的现实意义。     

浅析退耕还林对西宁市城区大气环境质量的改善与效益分析

通过对西宁市生态环境污染现状的分析,从提高城区绿化面积角度叙述退耕还林对改善西宁市城区生态环境质量的意义和效果,从地理、气候、绿化分布方面对退耕还林和城市生态环境改善做了定性分析,为西宁市生态环境保护和污染控制文献提供了决策依据。     

塔里木河干流区退耕还林（草）改善生态措施探讨

在国家实施西部大开发战略,提出退耕还林（草）,再造山川秀美的历史机遇面前,针对塔里木河干流区尤其是下游绿色走廊生态环境恶化的现实问题,分析产生问题的具体原因,阐明在合理开发、利用和配置水资源的前提下,退耕还林（草）是改善生态环境的有力措施以及实施退耕还林（草）对改善该区域生态环境的作用和意义,论述退耕还林（草）应掌握和处理好改善生态与经济发展、改善生态与农业结构调整、现代技术应用与传统方式的关系,探讨退耕还林（草）中合理的林草比例及科学的林草结合方式。     

新疆沙湾县生态农业建设与绿洲农业可持续发展探讨

新疆沙湾县国家级生态农业试点县建设实践证明,建立县级生态农业试点示范区,给新疆绿洲农业可持续发展积累了很好的发展模式和技术措施,是大力发展生态农业,促进农业生产良性循环,做好绿洲农业生态环境保护,合理利用绿洲农业资源,实现新疆绿洲农业可持续发展的最基本和必由之路。     

水利水电工程建设对荒漠河岸林草的影响分析研究

以新疆喀什噶尔河流域克孜河卡拉贝利水利枢纽工程为例,采用水均衡模型计算方法,从工程建成后区域荒漠河岸林草耗水量变化、荒漠河岸林草区地下水位变化情况、工程建成后洪水过程变化等方面分析工程建设对工程影响区荒漠河岸林草的影响。评价结果显示,工程建成后,与现状相比荒漠河岸林草植被的耗水量有所增加,区域平均地下水埋深仍能维持现状,在河岸林草生长和繁殖的6-9月,区域地下水位较现状略有上升,可满足大部分荒漠河岸林草植被的正常生长需求,水库对5年一遇标准以下洪水不调蓄,不会对荒漠河岸林草的繁衍存活产生明显不利影响。     

Forest Fragmentation and Landscape Transformation in a Reindeer Husbandry Area in Sweden

Reindeer husbandry and forestry are two main land users in boreal forests in northern Sweden. Modern forestry has numerous negative effects on the ground-growing and arboreal lichens that are crucial winter resources for reindeer husbandry. Using digitized historical maps, we examined changes in the forest landscape structure during the past 100 years, and estimated corresponding changes in suitability of forest landscape mosaics for the reindeer winter grazing. Cover of old coniferous forests, a key habitat type of reindeer herding system, showed a strong decrease during the study period, whereas clear-cutting and young forests increased rapidly in the latter half of the 20th century. The dominance of young forests and fragmentation of old-growth forests (decreased patch sizes and increased isolation) reflect decreased amount of arboreal lichens as well as a lowered ability of the landscape to sustain long-term persistence of lichens. The results further showed that variation in ground lichen cover among sites was mainly related to soil moisture conditions, recent disturbances, such as soil scarification and prescribed burning, and possibly also to forest history. In general, the results suggest that the composition and configuration of the forest landscape mosaic has become less suitable for sustainable reindeer husbandry.     

Variation in Vegetation Structure and Soil Properties, and the Relation Between Understory Plants and Environmental Variables Under Different Phyllostachys pubescens Forests in Southeastern China

Biodiversity maintenance and soil improvement are key sustainable forestry objectives. Research on the effects of bamboo forest management on plant diversity and soil properties are therefore necessary in bamboo-growing regions, such as southeastern China’s Shunchang County, that have not been studied from this perspective. We analyzed the effects of different Phyllostachys pubescens proportions in managed forests on vegetation structure and soil properties using pure Cunninghamia lanceolata forests as a contrast, and analyzed the relation between understory plants and environmental variables (i.e., topography, stand and soil characteristics) by canonical correspondence analysis (CCA). The forest with 80% P. pubescens and 20% hardwoods (such as Phoebe bournei, Jatropha curcas, Schima superba) maintained the highest plant diversity and best soil properties, with significantly higher plant diversity than the C. lanceolata forest, and better soil physicochemical and biological properties. The distribution of understory plants is highly related to environmental factors. Silvicultural disturbance strongly influenced the ability of different bamboo forests to maintain biodiversity and soil quality under extensive management, and the forest responses to management were consistent with the intermediate-disturbance hypothesis (i.e., diversity and soil properties were best at intermediate disturbance levels). Our results suggest that biodiversity maintenance and soil improvement are important management goals for sustainable bamboo management. To achieve those objectives, managers should balance the inputs and outputs of nutrients and protect understory plants by using appropriate fertilizer (e.g., organic fertilizer), adjusting stand structure, modifying utilization model and the harvest time, and controlling the intensity of culms and shoots harvests.     

Factors influencing the sustained participation of farmers in participatory forestry: a case study in central Sal forests in Bangladesh

Wide acceptance of sustainable development as a concept and as the goal of forest management has shifted forest management policies from a traditional to a people-oriented approach. Consequently, with its multiple new objectives, forest management has become more complex and an information gap exits between what is known and what is utilized, which hinders the sustained participation of farmers. This gap arose mainly due to an interrupted flow of information. With participatory forestry, the information flow requires a broad approach that goes beyond the forest ecosystem and includes the different stakeholders. Thus in participatory forest management strategies, policymakers, planners and project designers need to incorporate all relevant information within the context of the dynamic interaction between stakeholders and the forest environment. They should understand the impact of factors such as management policies, economics and conflicts on the sustained participation of farmers. This study aimed to use primary cross-sectional data to identify the factors that might influence the sustained participation of farmers in participatory forestry. Using stratified random sampling, 581 participants were selected to take part in this study, and data were collected through a structured questionnaire by interviewing the selected participants. To identify the dominant factors necessary for the sustained participation of farmers, logistic regression analyses were performed. The following results were observed: (a) sustained participation is positively and significantly correlated with (i) satisfaction of the participants with the tree species planted on their plots; (ii) confidence of the participants that their aspired benefits will be received; (iii) provision of training on different aspects of participatory forestry; (iv) contribution of participants' money to Tree Farming Funds. (b) The sustained participation of farmers is negatively and significantly correlated with the disruption of local peoples' interests through implementation of participatory forestry programs, and long delays in the harvesting of trees after completion of the contractual agreement period.     

Predicting soil erosion for alternative land uses

The APEX (Agricultural Policy-Environmental eXtender) model developed in the United States was calibrated for northwestern China's conditions. The model was then used to investigate soil erosion effects associated with alternative land uses at the ZFG (Zi-Fang-Gully) watershed in northwestern China. The results indicated that the APEX model could be calibrated reasonably well (+/-15% errors) to fit those areas with >50% slope within the watershed. Factors being considered during calibration include runoff, RUSLE (Revised Universal Soil Loss Equation) slope length and steepness factor, channel capacity flow rate, floodplain saturated hydraulic conductivity, and RUSLE C factor coefficient. No changes were made in the APEX computer code. Predictions suggest that reforestation is the best practice among the eight alternative land uses (the status quo, all grass, all grain, all grazing, all forest, half tree and half grass, 70% tree and 30% grain, and construction of a reservoir) for control of water runoff and soil erosion. Construction of a reservoir is the most effective strategy for controlling sediment yield although it does nothing to control upland erosion. For every 1 Mg of crop yield, 11 Mg of soil were lost during the 30-yr simulation period, suggesting that expanding land use for food production should not be encouraged on the ZFG watershed. Grass species are less effective than trees in controlling runoff and erosion on steep slopes because trees generally have deeper and more stable root systems.     

Evaluation of the economic and environmental impact of converting cropland to forest: a case study in Dunhua county, China

The Sloping Land Conversion Program (also known as "Grain for Green" or the Upland Conversion Program) for converting cropland to forest is one of China's most ambitious environmental initiatives, and is one of the world's largest land-conservation programs with a budget of RMB 337 billion (over US$ 40 billion). Although environmental impacts have played a vital role in the general reasoning and argumentation for forest plantations, environmental impact analyses have often received less attention than economic analyses in the planning of plantation forestry projects. The overall goal of this paper is to evaluate the program's environmental impact considering the farmer's interests and the potential social benefits due to carbon sequestration in different scenarios based on household and field survey data in Dunhua County. Our findings are that: (1) in many cases, the program did not give adequate consideration to land productivity and environmental heterogeneity when selecting plots; (2) more than half of the reforestation plots were on flat cropland (slopes of less than 5 degrees ); (3) in five of the eight townships, net incomes on reforested land were substantially above or below previous crop incomes, raising questions about the efficiency of the allocation of compensation to farmers participating in the program; (4) the potential carbon co-benefit increased the NPV of the program by 5954-7009 RMB/ha. In conclusion, we recommend that more attention should be paid to the quality of reforestation programs rather than just their scale and note that consideration of potential carbon sequestration co-benefits enhances the benefits of cropland conversion programs.