首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Agroforestry for production and ecosystem health is a centuries-old form of ecosystem management used in many cultures indigenous to Mesoamerica, yet implications of such practices for biodiversity conservation are not well understood. Agroforestry systems were studied using interviews of farmers and field surveys of tree and bird diversity in three communities surrounding the Calakmul Biosphere Reserve in Campeche, Mexico to examine how differences in forest management practices affect forest biodiversity. Tree diversity and bird species richness were higher in areas surrounding communities that generated a greater variety of forest products and that cultivated “restoration trees,” species planted to aid in regeneration of mature forest. We conclude that traditional ecosystem management methods in areas surrounding natural reserves as practiced by inhabitants who depend on resources in the reserve for survival are compatible with maintaining and perhaps enhancing diversity of bird and tree communities at the site level.  相似文献   

2.
《林业研究》2020,31(5)
Analysis of the change in forest cover is important to determine stand dynamics and the processes involved in disturbance and recovery. Forests of the core zone of the Monarch Butterfly Biosphere Reserve were studied using photo interpretation techniques, considering biennial changes between 1999 and 2013 and changes over the whole period of study 1999–2013. Error matrices were elaborated to determine the processes of change involved in both recovery and disturbance. The biennial changes for the whole period amounted to 2274 ha; 343 ha accounted as degraded in more than one biennial period. The total changes in forest cover between 1999 and 2013 involved 4902 ha, out of which, 2912 ha were affected by disturbance, and 1990 ha were recovered. For density and 2013 vegetation cover maps, the overall accuracy was 95.6% and 90.2%, respectively. By combining both maps, gradual processes were revealed that were not evident in separate analyses. This methodology is useful for the management and conservation of natural protected areas.  相似文献   

3.
Tropical deforestation and habitat fragmentation in areas around conservation areas have been an important element for discussion in the conservation and policy-making community. In this paper, we evaluate land cover change processes around one of the most important tropical dry forest reserves in the Americas: the Chamela-Cuixmala Biosphere Reserve, Mexico. The analysis is conducted at three scales: regional scale (coast of the State of Jalisco), proximity to the reserve (via a 30-km buffer zone analysis), and inside the Biosphere Reserve. The proximity analysis is complemented by a unique data set that represents the extent and boundaries of Ejidos (local land management units) in the region. Results indicate that areas surrounding the reserve have low deforestation, with Ejidos and buffer areas having more forest cover as they get closer to the reserve. The nature of this important phenomenon is discussed in the context of the socio-economic conditions of the local communities. Our work suggests that the creation of a network of “Ejidos’ Conservation Areas”, in the context of an approach that will recognize payments for environmental services provided to local communities, could contribute to the conservation and maintenance of the rich biodiversity in a region that has one of the highest levels of endemism in the world.  相似文献   

4.
Research was conducted during a 10-month period (August '89–May '90) in Arrondissement de Koumpentoum, Région de Tambacounda, Sénégal to evaluate factors influencing the adoption and farmer perceptions of the risks associated with agroforestry. Variables have been identified that are significant to agroforestry adoption and predictive equations are formulated. Land ownership and labor availability are identified as the two most significant factors which contribute to agroforestry adoption. They contribute to the sense of security of a producer thereby reducing the aversion to risking agroforestry adoption.
Précis On a fait des recherches pendant une période de dix mois (du mois d'août 89 au mois de mai 90) dans l'arrondissement de Koumpentoum, Région de Tambacounda au Sénégal pour évaluer les facteurs qui influencent l'adoption de l'agroforesterie et la perception du fermier du risque associé à l'adoption d'agroforesterie. On a indentifié les variables qui sont importantes à l'agroforesterie, et les équations prophétiques sont formulées. Le droit de propriété et la disponibilité de travail sont indentifiés comme étant les deux facteurs les plus importants qui contribuent au choix de l'agroforesterie. Ces facteurs contribuent au sentiment de sécurité d'un producteur, et de ce fait, ils réduisent l'aversion pour le risque de l'adoption de l'agroforesterie.
  相似文献   

5.
Abstract

The AMISCONDE Initiative was created and promoted by Conservation International (CI). This paper analyzes the approach to biodiversity conservation of the Costa Rican portion of the Initiative in the context of CI's mission statement. Global, national and local challenges to biodiversity conservation are briefly reviewed. Then, the implementation of the AMISCONDE Initiative is examined. To provide a basis for comparison, two other well-known Costa Rican conservation programs are summarized. The Initiative differs from these other programs in its central emphasis. AMISCONDE focuses on community development, apparently prioritizing development above biodiversity protection. The paper concludes with several recommendations: that the Initiative place far greater emphasis on biodiversity through education, employment opportunities and collaboration with other organizations interested in the biota of the region; and that the program evaluate its impact on the protected area's biota. This would enable CI to determine the degree to which the impacts of the Initiative are consistent with its mission.  相似文献   

6.
Abstract

We present an initial assessment of a community forestry program in the Bethel Cooperative in Northern Guatemala, which is located within the Mayan Biosphere Reserve, part of the Man in the Biosphere Program. Implementing the polycyclic felling system, 20 forest plots will be harvested in succession, one every 20 years. Within the harvest areas and at control sites, permanent monitoring plots have been established to study tree growth and natural regeneration. An average incremental growth rate was determined to be 0.68 cm/yr and was independent of whether or not harvest occurred, but was not independent of the commercial classification of the trees. Size class structure revealed a mixed-aged stand for all commercial categories that was minimally impacted by harvest. Natural regeneration of saplings and small trees may be affected by harvest and could impose long-term limits on the production of marketable trees. However, current cutting practices, size class structure, and conservative estimates of tree growth indicate that consistent harvests can be sustained well into the future. Community income from and participation in forestry-related activities were significant. Finding new markets, enhancing the marketability of new species, and developing non-timber forest resource trade and related activities will be crucial for the success of this program.  相似文献   

7.
Abstract

The use of fire in the La Amistad Biosphere Reserve, Panama, is a complex issue, especially given its biophysical, cultural, and socioeconomic context. A geographic gradient exists, depicting the threat from fire to the reserve. Areas around Volcan Baru have a high potential fire threat due to the biophysical aspects of the area and land-use activities. Fire use has a long cultural history in Panama. It continues to be frequently employed to clear land for swidden agriculture, cattle ranching on the Atlantic side of the Talamancan mountain range, and agricultural development on the Pacific side. Land tenure insecurity and perverse policies also incite its utilization for claiming land. Set fires often escape their boundaries and burn property, structures, crops, and fire-sensitive ecosystems. If left unchecked, anthropogenic fires pose a significant threat to both the ecological and socioeconomic well being of the Biosphere Reserve. Recommendations for the reserve's fire management plan focus on policy augmentation, educational outreach, monitoring, prevention, and fire research.  相似文献   

8.
Most agroforestry-adoption studies are based on surveys of "non-adopters." An understanding of the circumstances that have led to a change of attitude of the adopters will be valuable in our efforts to enhance adoption rates. This study was undertaken to provide such knowledge based on a large agroforestry extension project involving 200,000 farm families and covering 25% of all rural households in Haiti. A questionnaire-based survey of the project participants was conducted covering 1,540 households and 2,295 fields in four regions of Haiti. Information was recorded about each farm and family member through interviews with farmers and visits to their farms. The results confirmed that farmers make decisions about tree culture based on household- and field characteristics. Different farmers consider trees differently depending upon how they fit into their farm-family strategy. In general, farmers installed tree hedgerows on fields of less secure tenure, of lesser fertility, and steeper slope, while on closer, more fertile fields of greater tenure security, tree seedlings and fruit trees were more common and there was a greater density of mature trees (>10 cm DBH). More money was realized from sale of tree products on actively cropped fields in more secure tenure and having more fertile soil. Older farmers managed a greater density of trees, especially when the land was in secure tenure status. This broad-based study shows that agroforestry implementation strategies in poor countries such as Haiti should be based on a thorough knowledge of how farmers use household and field characteristics to make adoption decisions. It also suggests that agroforestry-adoption studies should account for the dynamic changes occurring during extended time periods.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

9.
The Lacandon Maya of Chiapas, Mexico practice a system of swidden agroforestry that mimics the surrounding ecosystem and its successional stages. Their fields rotate through grass (milpa), and shrub (acahual) and forest fallow stages that regenerate soil, nutrients, and seed banks. Each successional stage, including the fallow stages, produces over 25 types of crops, raw materials, and medicines. Lacandon traditionally do not use fertilizers, pesticides or herbicides. An emergy evaluation of Lacandon agroforestry was conducted to quantify resource use, productivity, environmental impact, and overall sustainability. Six systems were analyzed. The Emergy Yield Ratios of the systems ranged from 4.5 to 50.7, which indicated a high level of output per purchased investments. The agroforestry systems had minimal environmental impacts as shown by Environmental Loading Ratios between 0.03 and 0.38. The Emergy Sustainability Index (ESI) of the systems ranged from 12 to 1740, indicating a high level of sustainability. The high ESI values were partially due to a large fraction of renewable resources that varied from 0.72 to 0.97. ESI was dependent upon land area devoted to the system for each family, where greater land area resulted in higher values of ESI. Labor invested did not exhibit a direct effect on sustainability.  相似文献   

10.
The USDA Agricultural Research Service, headquartered at the South Central Family Farm Research Center, Booneville, Arkansas, recently initiated an agroforestry research program for the interior highlands and the southeastern United States. The purpose of the agroforestry program is to develop a research and technology transfer program in agroforestry that will provide additional alternative income opportunities for family farms of this region. The objectives of the program are: 1) to develop new information on the establishment, maintenance, and utilization of conifer and hardwood tree stands in open pastures, 2) to develop new knowledge in multiple-use management and their environmental impacts, and 3) to facilitate multidisciplinary networks and partnerships of farmers, technical specialists, scientists, and managers for accomplishing agroforestry research and technology transfer.  相似文献   

11.
This study explores the regeneration of 12 selected timber species within an area of selective logging in a neotropical rainforest in Guatemala. A part of the Maya Biosphere Reserve, in which timber harvest is performed by the cooperative Unión Maya Itzá, makes up the study area. We report the results of an inventory of 12 species over an area of 300 ha and detailed recording of saplings and seedlings for 10 selected timber species in five 1-ha plots. In the latter, characteristics of gaps (gap size and location, and vegetation cover) were also recorded. The recorded density of timber seedlings and saplings in the study area was low. The low present density of future harvestable timber species suggests that the total volume of harvested trees will decline from harvest to harvest in the future if an interval between subsequent logging events of 25 yr is used and if the logging intensity prescribed by the current management plan is upheld. Measures needed for forestry in this region to be sustainable are discussed.  相似文献   

12.
Agroforestry experimentation: Separating the wood from the trees?   总被引:1,自引:1,他引:0  
ICRAF has evolved and evaluated experimental approaches to agroforestry problems which will help resercchers reach practical conclusions most cost-effectively in the shortest possible time, and with only limited resources. This has meant looking into the experimental phases needed, developing the conceptual background to research problems which involve the complex spatial/temporal features of agroforestry systems, suggesting and initiating simplified field experimental designs and/or assessment methodologies, and establishing source and reference design materials about agroforestry research for distribution.These four sets of activities are outlined and briefly discussed in relation to some of the key research issues which have emerged.Suitable methods for many areas of experimental agroforestry are rapidly being defined, although some of the more complex issues (e.g. multistrata systems, on-farm research with multipurpose trees and tree/crop mixtures) still need a focused attempt to develop appropriate research methodologies.Head, Research Development Division, ICRAF  相似文献   

13.
InttxiductionAmongmanyinterestSrelatedtobiospllerereserve,pres-suresfromtoudsmdevelopll1entmigl1tbeamajorco11cerl1becausemostbiosphercrcscrvcsllave11atural,culturalal1dscenicattractionsfortourists.Intem1softourisn1man-agement,theecotourisn1l1asbeensuggestedasa11altema-tivefortl1econflictsbetweentourismdevelopnlelltalldnatureconservation,esPeciallyf()rtheprotected.areasucl1asbiosPherereserve.Ec()tourismhasbeco1lleI)oPulari11recentyearsaroundtl1eworid,a1ldson1escielltistsI1avemadegreateffortS…  相似文献   

14.
Efforts to improve the performance of agroforestry systems, and to expand the land area and number of people able to benefit from this integrative approach to agriculture and natural resource management, are constrained throughout the world by non-supportive land use policies. A growing sense of urgency that policy change is needed to enable agroforestry to flourish has contributed during the past two years to an unprecedented level of agroforestry policy assessment and planning activity.In the US, agroforestry has emerged from academia, where it has incubated since the mid-1980s, into the professional resource management arena. A multi-organizational agroforestry evaluation process has driven national policy and program formation to the forefront of the agenda of the agroforestry community, as it seeks to influence the 1995 Farm Bill. Internationally, the Consultative Group on International Agricultural Research and collaborators fostered a sequence of policy issue identification activities as a basis for setting strategic research priorities for forestry and agroforestry.Following a brief review of forces driving agroforestry development in industrialized and less developed countries, the paper highlights recent policy assessment initiatives in each sphere. Observations on the issues driving and the priorities emerging from these processes are offered, to lend perspective to the critical challenges facing the agroforestry policy research community. An explanation for pervasive constraints and inconsistencies in policy effectiveness is then explored, from which a promising approach to research intervention is forwarded.It is argued that social scientists might influence agroforestry policy most favorably at this critical juncture, as perceptions of inter-dependence increase among different stakeholders in the policy system, by employing interventionist, actor-oriented perspectives and participatory methods to facilitate policy innovation and evaluation. The approach is consistent with participatory technology design processes that earlier helped to establish agroforestry as a prototype for sustainable development.  相似文献   

15.
A mail-out survey questionnaire was developed by the Agroforestry group at the University of Guelph to determine the level of awareness and interest in the adoption of agroforestry systems by landusers from four townships in Wellington County, Ontario. The questionnaire investigated: (1) the current level of knowledge regarding windbreaks, woodlots and plantations, intereropping, riparian plantations and silvipasture, (2) the present level of participation in each of these systems on-farm, (3) the perceived benefits and/or drawbacks of each of these initiatives with respect to total farm income, income diversity, land rehabilitation, land value/equity, soil/water conservation, labour intensity, overhead and return on the term of investment.The majority of respondents were familiar with conventional agroforestry systems such as windbreaks and woodlots/plantations (80%, 62% respectively), therefore the level of interest in the adoption of these practices was significant (74%, 66% respectively). Response rates were lower for silvipasture, riparian plantations and intercropping, most likely as result of the low level of familiarity with these practices (20%, 32%, 4% respectively). Respondents commented that agroforestry systems would have a neutral effect on farm income, and would increase land stewardship. In some cases, interested landusers indicated a willingness to participate in agroforestry systems even though they anticipated increases in overhead and labour intensity; however, this was only true if they held land stewardship as a priority. Landusers were more concerned with the economic aspects of agroforestry, as a determinant to the future adoptability of particular practices. Age, gender, farm operation and farm size were not correlated with the adoption of agroforestry systems.The success of agroforestry programs on farms in the study area is largely dependent on the attitudes and willingness of landusers to participate in non-traditional agricultural systems.  相似文献   

16.
适宜的生境是珍稀濒危生物生存的决定性条件,对珍稀濒危生物生境的系统研究是生物多样性保护的前提。金丝猴是中国特有并且珍稀的濒危物种,黔金丝猴又是三种金丝猴中分布最为狭窄、对生境要求最为苛刻的一种。本文从黔金丝猴的最佳适宜生境、适宜生境和较适宜生境三个生境选择方面对生境内植物群落特征、环境因子、极端环境因子等进行了系统分析,对黔金丝猴的季节活动规律、活动区域和食物特点进行了系统的研究。结果表明常绿针阔混交林是黔金丝猴的最佳生存的植被群落,其最适宜的年均温度为8~15C,极端最低温度为-2.5C,极端最高温度为25C,最适宜生存的海拔高度为1500~1700m。在同一区域,植物多样性越多,越适宜黔金丝猴的生存。温度和食物是决定黔金丝猴种群活动范围大小的主要生境因子,海拔高度、植被群落特征、温度是黔金丝猴对生境选择的主要限制因子。图3表3参16。  相似文献   

17.
根据海南五指山自然保护区周边社区森林资源特性和社会经济特点,从该少数民族地区、原住民的社区环境林业研究入手,并结合海南五指山地区的“文明生态村”以及“国际旅游岛”建设的实际,旨在探索一条适合在海南少数民族聚居地区发展参与式森林资源管理的途径与方法,拓宽当地经济创收的渠道,持续保持当地生态资源优势,为实现社会和谐、经济持续发展提供保障。  相似文献   

18.
A possible method of protecting biosphere reserve core zones is to encourage transition and buffer zone activities which are compatible with the core and which provide sufficient returns to the human population to make entry into the core zone unnecessary. The AMISCONDE project is promoting block plantations and coffee/tree agroforestry systems to do this, but did not analyze their financial or economic feasibility. Unprofitable systems will not be adopted without subsidy and are not sustainable after a project ends. Analyses show internal rates of return exceeding 30% for coffee/tree combinations both with and without project subsidies. Coffee/tree systems have significantly higher returns than coffee without trees, reduce the risk from coffee price fluctuations, and reduce the need for chemical fertilizers. Returns from a block plantation of cypress are a small fraction of coffee and coffee/tree system returns, but still are positive and have the advantage of requiring much smaller initial investments. The systems analyzed seem likely to be sustainable and to contribute to project conservation and development objectives. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

19.
Introduction of two systems of agroforestry to the farmers portfolio is evaluated for their changes in cropping pattern, input use, income generation, farmers attitude towards risk and nutrient availability. Two different types of farmers are studied under both irrigated and dryland farming systems. Farm survey data collected from south Indian villages have been used with a mean-variance framework to identify the risk aversion levels of farmers. The results indicate that the risk-taking preferences of farmers should be given consideration in evaluating the impact of agroforestry systems. Among the two agroforestry systems analyzed, the one with drumstick is shown to increase the risk of crop production while the one with leucaena reduces the risk and enables farmers to invest in more risky cash crops. The impact of agroforestry on crop allocation, input use and income differs due to the differences in resource availability of farmers. The influence of agroforestry on nutrient availability of the farm households also differs based on the components of agroforestry, orientation of farming and the nature of farming systems. It is argued that design of agroforestry systems should consider differences in resource constraints in farming systems and risk attitudes of farmers towards their allocation decisions and that such considerations would largely enhance the successful adoption of agroforestry in developing countries.  相似文献   

20.
The use of non-timber forest products (NTFPs) has great potential for the conservation of natural resources and rural development. Palms are important NTFPs, providing numerous products, including leaves. The harvest of palm leaves rarely results in the immediate death of individuals and can be considered one example of the sustainable use of forest resources. However, in most cases basic ecological information, such as distribution and abundance of the species is unknown, as is information on the ecological implications of human impacts, such as leaf harvest and livestock grazing. In the tropical dry forests of northwest Mexico, leaves from the threatened palm Brahea aculeata are harvested for roofing material and represent an important NTFP. In this study, we assessed the distribution and abundance patterns of this species across 52 plots in the tropical dry forest of Sierra de Álamos-Rio Cuchujaqui Reserve (SARCR) in Sonora, Mexico. We also evaluated patterns of leaf harvest and cattle browse intensity on palm populations. We found that B. aculeata density is highly variable across the landscape with a mean (±SE) of 121.7 ± 36.3 ha−1. Results indicate that B. aculeata is primarily distributed near to arroyos and rivers. The highest densities were found in sites with low incidence radiation (<0.06 MJ cm−2) and narrow stream width of arroyos/rivers (<9.5 m). Palm abundance also varied within the plots, and B. aculeata attained its highest densities near to the arroyo edge (first 20 m from the edge), perhaps indicating a microhabitat effect on palm demography. Overall, fewer than 6% of the stems were seedlings. Leaf harvesting and browsing appear to affect demographic vital rates of the species; specifically we found a significant effect of harvesting and browsing activity on the proportion of reproductive active adults. Thus, low levels of seedlings in the populations may be the result of reduced fruit production by adults and higher mortality rates of seedlings due to livestock herbivory. Result from interviews with land owners also indicated that past land use, especially along arroyos might also have important impacts on the observed distribution, low densities and absence of recruitment in some areas. We believe current distribution and abundance of NTFP, such as B. aculeata at SARCR may be a result of combined effects of environmental factors and human impacts. Results from this study will be used to develop appropriate conservation, management and restoration plans of B. aculeata in the area.  相似文献   

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