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1.
Mid-subtropical forests are the main vegetation type of global terrestrial biomes, and are critical for maintaining the global carbon balance. However, estimates of forest biomass increment in mid-subtropical forests remain highly uncertain. It is critically important to determine the relative importance of different biotic and abiotic factors between plants and soil, particularly with respect to their influence on plant regrowth. Consequently,it is necessary to quantitatively characterize the dynamicspatiotemporal distribution of forest carbon sinks at a regional scale. This study used a large, long-term dataset in a boosted regression tree(BRT) model to determine the major components that quantitatively control forest biomass increments in a mid-subtropical forested region(Wuyishan National Nature Reserve, China). Long-term,stand-level data were used to derive the forest biomass increment, with the BRT model being applied to quantify the relative contributions of various biotic and abiotic variables to forest biomass increment. Our data show that total biomass(t) increased from 4.62 9 106 to 5.30 9 106 t between 1988 and 2010, and that the mean biomass increased from 80.19 ± 0.39 t ha-1(mean ± standard error) to 94.33 ± 0.41 t ha-1in the study region. The major factors that controlled biomass(in decreasing order of importance) were the stand, topography, and soil. Stand density was initially the most important stand factor, while elevation was the most important topographic factor. Soil factors were important for forest biomass increment but have a much weaker influence compared to the other two controlling factors. These results provide baseline information about the practical utility of spatial interpolationmethods for mapping forest biomass increments at regional scales.  相似文献   

2.
Heilongjiang province is the largest forest zone in China and the forest coverage rate is 46%. Forests of Heilongjiang province play an important role in the forest ecosystem of China. In this study we investi- gated the spatial distribution of forest carbon storage in Heilongjiang province using 3083 plots sampled in 2010. We attempted to fit two global models, ordinary least squares model (OLS), linear mixed model (LMM), and a local model, geographically weighted regression model (GWR), to the relationship between forest carbon content and stand, environment, and climate factors. Five predictors significantly affected forest carbon storage and spatial distribution, viz. average diameter of stand (DBH), number of trees per hectare (TPH), elevation (Elev), slope (Slope) and the product of precipitation and temperature (Rain Temp). The GWR model outperformed the two global models in both model fitting and prediction because it successfully reduced both spatial auto- correlation and heterogeneity in model residuals. More importantly, the GWR model provided localized model coefficients for each location in the study area, which allowed us to evaluate the influences of local stand conditions and topographic features on tree and stand growth, and forest carbon stock. It also helped us to better understand the impacts of silvi- cultural and management activities on the amount and changes of forest carbon storage across the province. The detailed information can be readily incorporated with the mapping ability of GIS software to provide excellent tools for assessing the distribution and dynamics of the for- est-carbon stock in the next few years.  相似文献   

3.
This paper focuses on how to build the model of precision fire hazard divisions in the level of forest resources sub-compartment.Based on 3D GIS technology and characteristics of forest fires in collective forest of southern China,this study utilized Lin’an City,Zhejiang Province as the experimental area.Forest fire factors were divided into 11 indexes from the three categories(social and economic factors,forestry characteristics,and meteorological characteristics) and weighted for analysis.Next,three eigenvectors(one for each category) were created to build a nonlinear mathematical model called precision fire hazard divisions for forests.Then,the model was used to optimize and test forest fire hazard divisions with the least squares.Results showed that experimental and theoretical values of error were less than 0.1. Thus,in the experimental area this model and the fire occurrence history matched.  相似文献   

4.
The purpose of this study was to determine a suitable model for investigating the effects of climate factors on the area burned by forest fire in the Tahe forest region, Daxing’an Mountains, in northea...  相似文献   

5.
This paper presents an approach based on field data to model the spatial distribution of the site productivity index (SPI) of the diverse forest types in Jalisco, Mexico and the response in SPI to site and cli-matic conditions. A linear regression model was constructed to test the hypothesis that site and climate variables can be used to predict the SPI of the major forest types in Jalisco. SPI varied significantly with topog-raphy (elevation, aspect and slope), soil attributes (pH, sand and silt), climate (temperature and precipitation zones) and forest type. The most important variable in the model was forest type, which accounted for 35% of the variability in SPI. Temperature and precipitation accounted for 8 to 9% of the variability in SPI while the soil attributes accounted for less than 4% of the variability observed in SPI. No significant differences were detected between the observed and predicted SPI for the individual forest types. The linear regression model was used to develop maps of the spatial variability in predicted SPI for the individual forest types in the state. The spatial site productivity models developed in this study provides a basis for understanding the complex relationship that exists between forest productivity and site and climatic conditions in the state. Findings of this study will assist resource managers in making cost-effective decisions about the management of individual forest types in the state of Jalisco, Mexico.  相似文献   

6.
《林业研究》2020,31(5)
Evaluating the influences of fine-scale habitat heterogeneity on the composition, diversity, structure and functioning of forests is critical to understand how tropical forests will respond to climate change and devise forest management strategies that will enhance biodiversity conservation and aboveground biomass stock. Here, we hypothesized that topographic and soil factors determine fine-scale habitat differentiation, which in turn shape community composition, species richness, structure and aboveground biomass at the local scale in tropical forests.To test this hypothesis, we selected two areas(each100 × 100 m) with contrasting fine-scale topographic conditions where all trees, palms and lianas with a diameter at breast height ≥ 10 cm were tagged and identified to species. In each selected area, 100 subplots of 10 × 10 m were established. We mainly found that higher topographic variability caused higher habitat differentiation with changes in species composition and community structure,but did not change species richness. Our habitat-scale analyses indicated that, in the less heterogeneous area, the distribution of species was more uniform along a fine-scale topographical gradient with no variation in convexity,which induced changes in structure and aboveground biomass, but not in species richness. The nonsignificant relationship between species richness and aboveground biomass may be attributable to species redundancy or functional dominance. This study suggests that environmental filtering is a fundamental process for shaping community assembly and forest functioning along a local topographical gradient in tropical forests.  相似文献   

7.
We examined the local community incentive programs to improve traditional forest management in three forested villages in Baneh city, Kurdistan province in the northern Zagros forests of western Iran. Zagros forests cover 6.07 million ha and support rich plant and animal diversity. Changes in local community social and economic sys-tems and the inefficiency of traditional forest management led to a criti-cal situation in the stability of forest regeneration in recent decades. Due to a shortage of productive and arable lands and resulting unemployment and poverty, people overexploited the Zagros forests. Outside interven-tion in traditional forest management creates conflicts between local peoples and forest management organizations. To achieve sustainable forest management, including forest resources conservation and im-provement of natural resource based livelihoods of communities, it is desirable to implement Forestry Incentive Programs (FIP) based on the important functions of forests. Detailed information on the so-cio-economics of communities, the effect of forests on local livelihoods, and lists of products extracted from the forest were obtained from a sur-vey of local communities though questionnaire, interview and observa-tion. We studied 276 households in three villages and completed 76 ques-tionnaires by householders in the quantitative analysis. Sampling was performed by simple random sampling (SRS). The needs of rural com-munities, such as livestock husbandry, mainly arise from the characteris-tics and environmental features of villages. We identified the driving forces, pressures, status, impacts and responses (DPSIR) to design incen-tive programs, by DPSIR analysis and interaction analysis. Evaluation of local community benefits from forests showed that in order to improve forest management, 319 dollars per year would be needed by each family as an incentive in 2010 to prevent lopping and firewood collecting, the main causes of forest degradation.  相似文献   

8.
We used a goal programming technique to determine the optimal harvest volume for the Iranian Caspian forest. We collected data including volume, growth, wood price at forest roadside, and variable harvesting costs. The allometric method was used to quantify seques- trated carbon. Regression analysis was used to derive growth models. Expected mean price was estimated using wood price and variable harvesting costs. Questionnaire was used to determine the constraints and the equation coefficients of the goal programming model. The optimal volume was determined using the goal programming method according to multipurpose forest management. LINGO software was used for analysis. Results indicated that the optimum volumes of species were 250.25 m3.ha-1 for beech, 59 m3.ha-1 for hornbeam, 73 m3.ha-1 for oak, 41 m3.ha-1 for alder, and 32 m3.ha-1 for other species. The total optimum volume is 455.25 m3.ha-1.  相似文献   

9.
The advent of modern forces and the changes in socioeconomic patterns of forest dwellers have increased the pressures on the forests. In order to mitigate such pressures and also to protect the forests and wildlife the model of protected areas networks has shifted and enhanced such pressures in the unprotected natural forests due to several reasons. Being a low profile category of protected status and continuous human settlements, the present study highlights the case of dry deciduous forests of Sarguja district of Chhattisgarh state of India. The major objectives of this study were to quantify the status of forests and wildlife and also to determine the extent of anthropogenic disturbances faced by the dry deciduous forests of central India. Transect and silent drive count methods were used for sampling wildlife and quadrat method was used for sampling vegetation. Besides, the local uses of various forest produces were also studied in view of understanding the people dependency on forests. The forest vegetation, in the study area, was pre-dominated by Shorea robusta, which had Madhuca indica, Diospyrus melanoxylon and Buchnania lanzan as the major companion species. The forest had either the high girth class mature tree species or the saplings. The low vegetation cover and density were due to the high anthropogenic pressures mainly in the form of heavy livestock grazing and collection of ethnobotanically important species. The study though reveals that the area is not rich in wildlife and the forest is fragmented, the area still supports some important species, which include many rare and endangered plants and animals. The findings of this study have been discussed in view of the management and conservation of the forest and wildlife in the dry deciduous forests.  相似文献   

10.
Accurate and efficient estimation of forest growth and live biomass is a critical element in assessing potential responses to forest management and environmental change. The objective of this study was to develop models to predict longleaf pine tree diameter at breast height (dbh) and merchantable stem volume (V) using data obtained from field measurements. We used longleaf pine tree data from 3,376 planted trees on 127 permanent plots located in the U.S. Gulf Coastal Plain region to fit equations to predict dbh and V as functions of tree height (H) and crown area (CA). Prediction of dbh as a function of H improved when CA was added as an additional independent variable. Similarly, predic- tions of V based on H improved when CA was included. Incorporation of additional stand variables such as age, site index, dominant height, and stand density were also evaluated but resulted in only small improvements in model performance. For model testing we used data from planted and naturally-regenerated trees located inside and outside the geographic area used for model fitting. Our results suggest that the models are a robust alternative for dbh and V estimations when H and CA are known on planted stands with potential for naturally-regenerated stands, across a wide range of ages. We discuss the importance of these models for use with metrics derived from remote sensing data.  相似文献   

11.
Abstract

Policies aimed at the exclusion of local communities from forest management are inappropriate, especially in a densely populated area with a low level of land ownership. Here we demonstrate that termination of the Tumpang Sari program, which allowed local communities access to areas for controlled cultivation in several parts of the state forest area in West Java, Indonesia, did not cease illegal cultivation of the forestland. Moreover, illegal cultivation continues to be conducted by many people. This has created not only a land degradation problem but also has affected other forest resource users, the fuelwood collectors and the dairy cattle farmers. Therefore, the re-involvement of local communities in better forest management is required to avoid further environmental degradation as well as enhance poverty alleviation programs.  相似文献   

12.
基于金融精准扶贫的我国林权抵押机制设计   总被引:1,自引:0,他引:1       下载免费PDF全文
金融精准扶贫是提高金融市场效率、促进地区经济发展、增加贫困地区林农收入的有效手段,但作为金融精准扶贫重要措施的林权抵押政策在我国实践过程中存在着定位不清、扶贫对象不明、扶贫效率低下的问题。文中阐述金融精准扶贫的内涵与理论基础,认为应该设计以林权抵押为核心的金融精准扶贫政策,从构建团体抵押机制、建立多功能和多层次农村金融体系、完善林业经营保险体系、赋权贫困群体参与金融市场等方面完善林权抵押机制。  相似文献   

13.
生态护林员政策是我国开展生态扶贫行动的一项创新性举措,是践行“两山”理念、贯彻落实生态文明思想的一个生动实践。生态护林员政策的有效实施实现了脱贫增收与生态保护双赢的目标。2022年中央一号文件明确提出要对生态护林员政策进行优化调整。同时,在我国全面脱贫任务目标完成的背景下,生态护林员政策的任务重心也应从生态补偿脱贫一批的目标中脱离出来;过渡阶段巩固拓展脱贫攻坚成果与乡村振兴有效衔接目标的提出,也使得生态护林员政策适时调整更加迫切。文中总结归纳我国生态护林员政策提出的理论框架,分析其政策实施机制及成效;结合实地调研情况,探讨目前生态护林员政策面临的问题,包括生态护林员选聘范围受限、指标分配不平衡、缺乏生态护林员收入保障和激励机制、政策资金来源单一有限、监管与考核机制不健全、生态护林员综合素质不高等;最后对生态护林员政策动态调整提出对策建议。  相似文献   

14.
林业生态扶贫研究进展   总被引:1,自引:1,他引:1  
林业生态扶贫是改善贫困地区生态状况、提高人们生产生活水平的优先选择。林业作为一项公益性事业和基础性产业,在生态扶贫中不仅发挥了生态效应,也体现出较强的经济效应和社会效应。文中在回顾国内外相关文献及实践的基础上,梳理林业与生态扶贫之间的关系,探讨林业生态扶贫的理论逻辑,总结我国政策倾斜式、产业发展式、机制创新式3种林业生态扶贫实践模式,概述林业生态扶贫的保障政策,最后进行评述和展望。  相似文献   

15.
新平县国土总面积 4 2 99 6 4km2 ,由于地形陡峭 ,高差悬殊 ,山区面积占 98% ,其水土流失面积占总面积的 33 5 %。因此 ,退耕还林是山区人民脱贫致富的需要 ;是防灾减灾保护国家财产和人民生命安全的需要。计划用 10年时间 (2 0 0 2~ 2 0 10年 )分两阶段完成退耕还林 790 0hm2 ,发展生态林、竹林、核桃、印楝等经济林 ,届时可以基本实现脱贫致富 ,并增加森林覆盖率 1 88个百分点。并提出了实现目标的措施  相似文献   

16.
指出了新时期切实做好扶贫移民安置、发展移民经济,构建社会主义新农村,是当前地方政府的重要工作。而移民满意度是评价扶贫移民工作成败的重要因素,由于地区不同因素的影响,扶贫移民工作在效果上是有较大差异的,从而导致移民满意度的差异也相当明显。下盘石村和柏坡底村同属黄河流域晋陕峡谷段的国家级贫困县,仅一河之隔,同属于村内扶贫移民搬迁的对象,但在搬迁过程和结果上的差异悬殊,两村之间通过对比所表现出的问题涵盖了黄土高原区村内扶贫移民存在的主要问题。在实地调研的基础上,以晋陕两省两个自然村的农户调查数据为依据,对影响村内搬迁农民满意度差异的原因进行了分析。结果表明:两村移民满意度存在着较大的差异,而造成这种差异的原因是多方面的,主要表现在补助标准、宅基地使用费、搬迁后移民生活状况、搬迁后产业状况及搬迁过程中具体措施上的不同。  相似文献   

17.
Increasing attention has been paid to the question of whether and how community forestry links with poverty reduction in the mountainous regions in developing countries. Household-based community forestry was first implemented in Yunnan and spread over other parts of China in the 1980s. In this forestry management system, rural households are the main actors. Household forestry is a form of small-scale community forestry and suits the rural areas of China, where social overhead capital and skilled human resources are lacking. Community forestry has played a remarkable role in guiding and facilitating rural poverty alleviation in Huoshan County, Anhui Province. This paper describes how the community forestry project in Huoshan County has helped the farmers improve their livelihoods through the creation of a forestry model involving science and technology demonstration households and independent farmers’ organisations. The sustainable poverty alleviation model developed in Huoshan has proved to be effective in poverty alleviation and environmental protection, featuring the participatory forestry components of the project, namely household forestry, science and technology demonstration households, and independent farmers’ organisations. With technological and financial aid from government, the local farmers were able and willing to establish this small-scale forestry management system, planting fast-growing multiple-use tree species with substantial economic benefits.  相似文献   

18.
我国林业产业化扶贫长效机制研究现状及展望   总被引:2,自引:1,他引:1  
林业产业化扶贫是践行“绿水青山就是金山银山”理念、可持续发展理念、绿色减贫思想、美丽中国战略与乡村振兴战略的重要途径。目前,我国对于林业产业化扶贫长效机制的研究重点集中在扶贫模式总结、扶贫效果评价以及问题与经验分析等方面。文中通过总结评述既有研究成果,对今后的林业产业化研究进行了展望:1)目前相关研究缺乏对林业产业化参与主体的整体分析以及主体之间互动机制的研究;2)从制度的角度构建长效机制是巩固扶贫成果、防止返贫的重要前提。3)农户脱贫稳定性测算与长效扶贫机制评价相结合的研究是未来发展的方向之一。  相似文献   

19.
本文针对广东省林业建设中面临的两个主要任务,提出发展灌木经济林在优化森林生态系统和实现山区农民增收的思路,列举了可供我省发展的部分药用和蔬菜经济灌木树种,并对发展灌木林的观念与体制等问题展开了讨论。  相似文献   

20.
Indonesia experienced massive deforestation in the last decades where rapid oil palm expansion has been considered as one of the main drivers. This article shows that the process of deforestation and the rapid oil palm expansion cannot be viewed in isolation from broader development contexts. Various actors at local, national, and global levels have used development narratives and poverty alleviation through various policies and institutional setting to create spaces and opportunities for oil palm development. These actors also deliberately created the notion of forest crisis by omitting the values of forest environmental services to justify forest conversion into oil palm plantations. These multiple factors shaped the speed and the direction of oil palm expansion in Indonesia. This rapid oil palm expansion in Indonesia has resulted in massive LUCC and serious environmental problems. Given these complexities, a single policy will not be sufficient when it comes to managing the consequences of rapid oil palm expansion in Indonesia.  相似文献   

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