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1.
Integrated management of natural resources and the multiple use of trees and forests have prevailed in most European societies since prehistoric times. In the Middle Ages, expanding and intensified agriculture resulted in the separation of trees from agricultural fields. During the last century, with the introduction of sustainable and highly productive forest management, the goal of increased wood production has been achieved in most parts of central, northern, and eastern Europe. Today, agroforestry is not considered to be an important land-use option within the region; however, there are many practices that could rightfully be classified as agroforestry. These include tree/crop systems in which trees provide products and/or environmental benefits, and tree/animal systems in which animals are grazed in forests or open woodlands.The future seems to offer some prospects for agroforestry. Large areas, hitherto used for food production, are either marginally suited to agriculture, or will probably be taken out of production due to agricultural policy considerations. Agroforestry may, at least in part, offer alternatives for the use of such lands. The availability of (surplus) fertile soils, capital, and labor may provide incentives for site-adapted forms of agroforestry, including improved fallow management. The focus of such systems would be on maintenance of biodiversity in the landscape, environmental protection, recreation, and product diversification.There are numerous expectations as to what agroforestry might provide for the land holder and for society as a whole. These expectations should be carefully analyzed and evaluated prior to political decisions on future land use. The promotion of agroforestry requires overall investment; agroforestry does not happen by itself. A set of integrated actions — not isolated efforts — must be implemented if agroforestry is to become a successful land-use option.  相似文献   

2.
Pessimistic forecasts often suggest that widely spaced trees enjoying free growth (no competition with other trees) will fail to provide high quality timber. This challenges the temperate agroforestry practice of planting widely spaced trees to produce high quality timber. We analyse tree growth data from recent temperate agroforestry plantations aged three to eight years, featuring low tree plantation densities (50 to 400 stems ha−1), the association of trees with intercrops (silvoarable systems) or animals (silvopastoral systems), and the use of plastic shelter tubes to protect trees (1.2 to 2.5 m high) and avoid damage by cattle or sheep in pastures or facilitate maintenance in silvoarable systems. The plantations are located in climates ranging from Mediterranean, dry central temperate plains, cold and wet central uplands to mild oceanic areas. Some plantations included a forestry control (high density of plantation, no tree shelter, no intercropping nor grazing). Trees were evaluated for height and diameter growth and stem form (straightness and absence of knots). Trees in most agroforestry plots grew satisfactorily, often faster than in forestry control plots. In some experimental plots, average annual height increments as high as 1 m and diameter increments as high as 1.5 cm were observed. Few agroforestry plantations were unsuccessful, and the reasons for the failures are discussed: animal damage in silvopastoral plots, but also a wrong choice of tree species unsuitable for local soil and climate characteristics. From these early results we can formulate some guidelines for designing future agroforestry plantations in temperate climates, concerning tree density, use of tree shelters and care required for widely spaced trees. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

3.
A number of tropical forage legume species were sown in Turrialba., Costa Rica, in plots in the open and under an even cover of Pinus caribaea var hondurensis of basal area 30m2/ha. Mean light level under the trees was 18% full sunlight. After 19 months, species showing good shade tolerance and adaptation to local conditions were: Centrosema spp., Desmodium spp., Flemingia congesta, Galactia striata. Species of poor performance in the shade were: Stylosanthes spp., Indigofera hirsuta, Cajanus cajan, Stilozobium sp.. Canavalia ensiformis, an annual, grew well in the shade, as did Lablab purpureus and Vigna unguiculata. It is suggested that further work be done on the shade tolerant species for eventual use as components of silvopastoral systems. Recommendations are made concerning germplasm collections, evaluation methodology and research for silvopasture development.
Resumen Se sembraron especies diversas de leguminosas forrajeras en Turrialba, Costa Rica, en parcelas al descubierto y bajo una cobertura uniforme de Pinus caribaea var hondurensis con area basal de 30 m2/ha. El nivel medio de iluminación bajo los pinos era 18% del nivel a pleno sol. Despues de 19 meses las especies que mostraron buena adaptación a la sombra eran: Centrosema spp., Desmodium spp., Flemingia congesta, Galactia striata. Especies de bajo rendimiento en la sombra eran: Stylosanthes spp., Indigofera hirsuta, Cajanus cajan, Stilozobium sp., La planta anuál Canavalia ensiformis creció bien bajo sombra, como tambien lo hicieron Lablab purpureus y Vigna unguiculata. Se sugiere que se investiguen las especies mencionadas como bien adaptadas al sombreamiento para uso en sistemas silvopastoriles. Se presentan recomendaciones sobre colecciones de germoplasma, metodologia de evaluación y investigación para el desarollo de sistemas silvopastoriles.
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4.
The diversity and organization of the mammalian community is related to the vegetation structure of the coffee plantations in the area of Barranca Grande, in the State of Veracruz, Mexico. Four transects (each 200 m in length) were used to study the vegetation structure within the coffee plantation, and 178 night/traps, tracks registration and information from local people, were used in order to become familiar with the mammaliancommunity. The sample period was from October 1989 to February 1991. The 24 mammals of medium-size species present in the area were classified using two measures of ecological diversity, locomotion and foraging in order to understand the guild organization. If the complexity of the plantation is reduced, the number of guilds occupied could suffer a loss of 45% and 43% in ecological richness and diversity, respectively, and 24% in the equitability of the mammalian fauna. We recommend the maintenance of a high diversity in the tree stratum (shade species), in this case, species such as Inga jinicuil, banana (Musa sapientum), Citrus spp., coyo avocado (Persea schiedeana), mango (Mangifera indica); species which could provide food resources and protection for the mammals.
Resumen En el área de Barranca Grande, Estado de Veracruz, México, se estudió la relación que tiene la estructura de la vegetación de los cultivos de café con la diversidad de la comunidad de mamíferos medianos. Para ello, se establecieron 4 transectos fijos de 200 m de largo cada uno, en los que se tomaron los datos de los diferentes estratos. Para conocer la fauna demamíferos, se hizo un muestreo con trampas Tomahawk (178 noches/trampas), registro de rastros así como encuestas a la gente que vive en la zona, entre Octubre de 1989 y Febrero de 1991. Se registraron 24 especies de mamíferos medianos que fueron clasificados utilizando dos medidas de diversidad ecológica, locomoción y forrajeo, para conocer la organización en gremios. Si se reduce la complejidad de los cafetales, puede existir una reducción hasta del 45% en el número de gremios ocupados, 43% en la riqueza y en la diversidad ecológica, y 24% en la equitatividad. Se recomienda mantener una alta diversidad en el estrato arbóreo, en este caso especies como el jinicuil (Inga jinicuil), plátanos (Musa sapientum), cítricos (Citrus spp.), pagua o aguacate (Persea schiedeana), mango (Mangifera indica), serían recomendables ya que proporcionan recursos alimenticios y protección a la mayoría de los mamíferos.
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5.
Both model and field estimations were made of the damage inflicted to coffee plants due to the harvest of timber shade trees (Cordia alliodora) in coffee plantations. Economic analyses were made for different coffee planting densities, yields, and both coffee and timber prices.Damage due to tree felling and log skidding should not be a major limitation to the use of timber shade trees in coffee plantations. The timber price that would balance all discounted losses and benefits to zero, for scenarios with and without trees ranged between 8–20 US $/m3 (current overbark log volume at the saw mill yard is US$ 66/m3). There will be lower margins for coffee damage in high yielding plantations, specially in years of good coffee prices. Nevertheless, the use of timber shade trees is recommended even in these scenarios.  相似文献   

6.
The effects of two pruning regimes on the above-ground biomass allocation and nodulation of Gliricidia sepium (Jacq.) Walp. (Leguminosae: Robinieae) were studied in a cut-and-carry forage production system under humid tropical conditions in Guadeloupe, French Antilles. The grass layer composed of a mixture dominated by Paspalum notatum Flügge (80%) and Digitaria decumbens Stent. The pruning regimes were partial pruning (ca. 50%) every two months and complete pruning every six months. The complete pruning caused an almost complete turnover of N2 fixing nodules. The nodule biomass decreased after the partial pruning, but the turnover was not complete. The nodule to foliage biomass ratio followed the same pattern under both treatments, and the values of the ratio converged towards the end of the experimental period. The maxima of standing nodule biomass were 7.2 and 13.0 kg ha−1 in the partially and completely pruned trees, respectively. The cumulative leaf fodder harvest was higher under partial pruning management, due to smaller litter loss. The branch biomass production was higher under complete pruning management. Grass production was not affected by the pruning pattern of G. sepium. It was concluded that the partial pruning management produces more fodder in the studied association, and the nodulation probably adjusts to the canopy N requirements. The potential N release to soil in the turnover of nodules of G. sepium (max. 0.82 kg ha−1) is negligible compared to the N export in tree and grass fodder harvest, 190 and 215 kg ha−1 in partially and completely pruned plots, respectively. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

7.
珍稀濒危树种的迁地保育以及在城市建设中的作用   总被引:3,自引:0,他引:3  
成功地迁地保育了珙桐、夏蜡梅等60种珍稀树种,其中40种已开花结果,占总数的66%。有的树种已形成了自然种群和更新苗。在迁地保育中,一方面应注意观测树种本身的潜在适应能力,适应能力越强越容易成功;同时应注意"引种保育区"的小生境条件和原产地生境条件的相似程度,相似程度越高越容易成功。文内还讨论了迁地保育的技术措施和珍稀树种在城市建设中的作用。  相似文献   

8.
观果树种配植与城市鸟类生物多样性保护   总被引:13,自引:0,他引:13  
通过对观果树木,尤其是冬季挂果的观果树木的果期物候调查,以及在冬季留鸟对挂果树木的访问情况记录,讨论了观果树木在城市园林中配植与城市鸟类多样性保护的关系。合理配植冬季挂果树种,对吸引更多的鸟类、维持城市生物多样性有重要意义。  相似文献   

9.
叙述了道县古树资源的种类、数量、年龄及其分布,分析了管理中存在的问题,并就如何加强古树资源的保护和利用,提出了大力宣传,依法保护、加大资金投入,完善建档挂牌工作等管理措施和树洞修补、支撑加固、设避雷针、设围拦、病虫害防治、灌水松土施肥、换土复壮等技术措施的保护建议.  相似文献   

10.
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。  相似文献   

11.
Although agroforestry practices have been used in Central America since pre-Columbian times, scientific initiatives in agroforestry began only about 15 years ago in this region. This paper describes the evolution of agroforestry in the Central American region, and discusses the relative merits of generating new procedures or encouraging traditional practices. This is followed by an analysis of several particularly promising practices—use of N-fixing trees to shade cacao and coffee, timber trees in pastures, and living fenceposts. Finally, a list of research gaps and recommendations for future efforts is presented. It is concluded that, from the perspective of scientific knowledge, agroforestry in Central America has taken off but the link between scientific knowledge and effective field application is still lacking.  相似文献   

12.
The rapid appraisal and farmer selection procedures, preceding the establishment of over fifty agroforestry research trials on farms in Talamanca, Costa Rica are described. The highest probability of success and impact of these long-term collaborative trials is obtained by selecting innovative, experienced, motivated and locally respected farmers. The methodological lessons learned from implementing three types of researcher managed trials (shade-cacao; black pepper on living support posts; timber production in boundary lines) are discussed. The importance of fitting farmer selection criteria to project objectives, experimental designs to on-farm limitations, and project goals to farmers' goals, are emphasized.  相似文献   

13.
为了加强对河北省古树名木的保护和管理,文章从管理措施和保护措施两个方面进行了具体的研究。管理措施包括复壮和养护两个方面;采取划分河北省古树名木保护管理区、加强宣传教育、出台相关的条例和管理办法、加强对古树名木资料的收集和建档工作、加大对古树名木保护资金的投入、设定有效的标志物、建立健全管护组织、加强对古树名木保护的科学研究等8个方面措施。对古树名木的保护与管理措施的深入研究,为河北省古树名木的管理和保护工作起到重要的指导作用。  相似文献   

14.
苏州市古树名木资源现状及其保护对策   总被引:6,自引:0,他引:6  
为更好地保护和利用苏州的古树名木,在古树名木调查的基础上,对苏州古树名木生存现状和存在的主要问题进行分析。苏州古树名木共计2279株,分属42科69属90种。在分析古树名木现状的基础上,建立古树名木保护评价指标体系,得出古树名木保护评价指数,确定古树保护优先级。分析表明:目前有250株古树名木,列入1a期优先保护计划,其中第1批救治对象共43株。建议根据古树名木现状实施相应的保护措施及不同的开发利用方案。  相似文献   

15.
俗话说“三分种,七分管”,树木栽植后必须进行科学、及时、细致的养护,才有利于树木成活。从多个方面阐述新栽树木在成活期的养护管理,以期对春季园林管理。  相似文献   

16.
北京市古树名木管理信息系统的设计与实现   总被引:1,自引:0,他引:1  
根据北京市古树名木现有的数据资料和信息技术,设计并实现了一个基于Web的北京市古树名木管理信息系统。服务器端为管理者提供了一个功能完善的信息管理平台,客户端实现了对北京市区和郊区古树名木基本属性数据的查询,对病虫害防治措施的介绍和站内搜索,以及用户对一些信息的反馈和管理者的回复等功能。  相似文献   

17.
南京地区极端低温对常绿绿化树种景观的影响及分析   总被引:2,自引:0,他引:2  
通过调查2004年冬季南京市7个不同地域常绿绿化树种所发生的冻害情况,分析了该地当年温度、降水等气候因子变化对常绿绿化树种景观效果的影响.  相似文献   

18.
The agroforestry systems of cacao (Theobroma cacao) under laurel (Cordia alliodora) and cacao under poro (Erythrina poeppigiana) were studied at CATIE, Turrialba, Costa Rica. An inventory was taken of the organic matter and nutrients (N, P, K, Ca, and Mg) separating the species into their compartments (leaves, branches, trunks and roots). Studies of the litter and of the mineral soil (0–45 cm) yielded these results: Patterns of nutrient accumulation are discussed in relation to the characteristics of these agroforestry systems.  相似文献   

19.
The design and methods are described of farmer-managed action-research to test the survival and performance of trees planted in paddy fields of private farms in Bangladesh. Farmers received seedlings of indigenous and exotic trees with extension advice on planting methods and care. Planting was done in systematically designed randomized modules involving twelve thousand trees up to the end of 1990. Survival and condition of individual seedlings were monitored twice annually, and mortality was replanted for up to three years after which little further mortality occurred.Stocking rate, including original survivors and replanted seedlings, tended towards 55% after six years. The main factors conductive to survival were the presence of a nurse crop in the field at the time of tree planting, and the quality and size of planting stock. Cause of death could not be attributed in about 8% of mortality. Main recorded causes of tree mortality, in order of frequency, were livestock browsing, physical damage during cultivation or harvesting operations, pests or diseases, drought, and flooding.About 15% of tree mortality was due to losses of complete modules owing to catastrophic flooding, land disputes, and public works such as roads or pipelines. It is suspected that some of this mortality may be unacknowledged changes of mind and deliberate removal by the participating farmers.  相似文献   

20.
Samanea saman (Jacq.) Merr. (syn. Albizia saman (Jacq.) F. v. Muell.) is a large tree, native to tropical America, which has now become widespread throughout the humid and subhumid tropics. Although noted as a promising agroforestry species, there is little specific research that substantiates this potential. On the basis of a review of its biology, ecology and recorded uses, it is concluded that the most appropriate use for S. saman would be in an extensive silvopastoral system for cattle production. The tree provides excellent protective shade, and produces highly palatable pods that are suitable as a dry season feed supplement. Additionally, there are reports of enhanced grass production beneath its canopy indicating a potential role in maintaining or improving the productivity of tropical grasslands. It is concluded that the tree should receive more research attention, focusing particularly on its interaction with the herbaceous understorey and the identification of provenances adapted to a variety of environmental conditions. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

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