农田防护林带效益的生态经济评价

农田防护林带的效益,在于其对农田土壤的改良作用(增加农作物收获量)和生态效用(防止土壤风蚀与冲刷,改善农田水文状况、旅游效益及其他)。把这些方面综合起来,对积极影响国民经济水平的农田防护林效益可予生态经济评价。其用货币形式表现的评价量(卢布)按下列公式计算: 式中:——国民经济的生态经济效果;——国民经济的生产效果;——生态效果;——由于农田防护林带本身占用耕地而损失的净收入。确定第一组成部分(国民经济的生产效果)时的特点,在于按统一核算(税册的)价     

积极开展以治理风蚀为重点的土地退化防治项目示范点建设

<正>项目示范点范丁乡沙滩村地处阿拉山口主风道前沿,土地风蚀较严重。近年来,每年的大风天气,在带走1～3厘米地表优质土的同时,时常将已经播种的棉花薄膜掀起,造成损失,致使土地资源退化,给村民带来了巨大的损失。同时,水蚀严重,该村西侧是精河河,许多农户的耕地靠近河床,每年洪水泛滥之际,洪水冲上堤岸,冲毁农田,造成土地大量流失,严重时,会使村民受到颗粒无收的重大损失。     

围场县农田防护林体系现状及建设对策

<正>农田防护林是以保护耕地免受风蚀沙埋,改善农田小气候,促进农作物稳产高产为目标所营建的防护林,是防止土地沙漠化,改善生态环境和促进农业经济发展的重要技术措施,特别是进入21世纪以来,中共中央、国务院对生态环境非常重视,加强生态建设,维护生态安全,     

奈曼旗：扁杏产业铺就山区致富路

北大营子村位于通辽市奈曼旗新镇西南部，辖9个村民小组，共444户，1702口人。全村总土地面积5万亩，境内沟壑纵横，居民多居住在沟内，耕地大部分位于丘陵坡地上；地表水缺乏，地下水难以利用，农田没有灌溉条件。村民过的是靠天吃饭的日子。由于近年干旱少雨，当地农业遭受了比较严重的损失，群众再次面临返贫的尴尬境地，如何找到脱贫致富的新路迫在眉睫。     

海丰农场农田防护林调查中遇到的几个问题

海丰农场距江苏省大丰县县城约20公里,属上海市农垦局管辖。1973年建场,全场面积约1.67万公顷,其中耕地近0.67万公顷,还有0.67多万公顷土地有待开发。现有农田防护林,主要树种为刺槐、苦楝、白榆,1991年开始栽种欧美杨。为了全面规划,林业作为一个产业,海丰农场与南京林校合作,1993年4～5月份进行了农田防护林调查,为农场农田防护林规划设计打下了坚实基础。     

世界每分钟环境灾难

耕地:全世界每分钟损失耕地四公顷,每年损失两千一百万公顷;森林:全世界每分钟有二十一公顷森林消失,每年消失—千一百万公顷;沙漠化:全世界每分钟有十一公顷土地沙漠化,每年沙漠化土地为六百万公顷:泥沙:全世界每分钟有四点八万吨泥沙流入大海,每年流入大海的泥沙为二百五十亿吨;     

布扎克公社实现林网化

布扎克公社在和田县的历史上是一个聚居着15500人口的维吾尔民族,有土地四万亩,由19个大队种植着25600亩耕地。粉碎“四人帮”后,公社党委率领全社广大干部和社员群众,狠抓了以改土治水为中心的农田基本建设,水、田、林路综合治理,改变     

基于村域尺度的传统耕作制度对耕地生产能力提升的思考

耕地是农业发展的根基,只有提升耕地生产能力,才能守住粮食安全底线。从村域尺度,采用文献研究法、实地调查法,分析粮食生产现状,剖析了研究区的传统耕作制度及其耕地生产能力制约条件,从中得出提升耕地生产能力的思考。结果表明：(1)研究区早籼稻和晚籼稻生产成本呈现增加趋势,其中机耕成本为170～180元/亩、收割成本为120～300元/亩、农药成本为120～130元/亩、化肥成本为120～230元/亩、水稻种子成本为47～50元/斤。(2)耕地生产能力制约因素主要是耕作方式陈旧、收割业务不完善、生产成本高、种植粮食补贴少以及农田基础设施落后,从提升农民生产意识、改进耕作方式、发展农业机械化、完善农村基础设施4方面提高耕地生产能力,为当地管理土地、增加粮食产量、促进农业农村现代化发展提供参考。     

重新规划建林网

通辽市双宝乡总土地面积12.4万亩,其中耕地6.1万亩。近年来,双宝乡林业生产发展迅速,农田防护林建设尤为突出。这个乡由于前些年忽视林业生产,偏重农业种植,致使农田防护林带不成型,缺株断带,新造林又保存不好,出现了万亩耕地无林带的局面。1986年,全乡农防林只剩936亩,仅占耕地面积的15.3％,根本起不到保护农田的作用,粮食产量低而不稳。这一年,乡党委针对农业生产实际,认真研究林业建设问题,摆正林业在大农业中的位置,克     

内蒙古乌兰察布市后山以林治沙进行生态建设30年--以商都县西井子乡为例

内蒙古乌兰察布市后山地区20世纪30年代陆续开垦为旱作农田，特殊自然环境使风蚀沙漠化强烈发展，经过30多年的耕作，70％以上土地显现灌丛沙堆密集，出现风蚀劣地、片状沙地，耕地则呈现砾质化、耕垄积沙的典型风蚀沙漠化景观。20世纪70年代开始建设农田防护林，到90年代农田防护林起到防护作用。20世纪末进行农业结构调整，生态环境循环，经济也进入快速发展的阶段，创造了“以林治沙，农田林网建设为中心”的生态环境建设模式，商都县西井子乡则是这一模式的样板。     

中坝村退耕还林效益分析

笔者通过对秭归县茅坪镇中坝村退耕还林的现场详细调查,主要是水土保持经济林的单位面积效益进行评价,并使之与退耕还林前的农业生产效益相比较,阐明退耕还林的经济可行性和采取合理的相应措施。     

退耕还林不同植被经营模式综合效益评价

对鄂西地区退耕还林三种不同植被配置模式和坡耕地农作系统模式的综合效益进行了评价和比较。结果表明,以生态型经济林植被配置模式综合效益最高,其次分别是生物篱模式和水土保持林模式,坡耕地农作系统模式效益最差。     

Respiratory Parameters Define Growth Rate,Species Distribution and Adaptation to Temperature

Abstract

Agricultural expansion by smallholder producers has been identified by management agencies as one of the main threats to the ecological integrity of La Amistad Biosphere Reserve, in Panama and Costa Rica. Promotion of cacao agroforestry has been proposed as a way to reduce the need for farmers to clear new land within the reserve. In order to realize this goal, the larger cultural, economic, and political forces that motivate agricultural expansion need to be examined, looking beyond the smallholder practices that are the immediately apparent causes of ecological degradation. The four main assumptions behind the proposal to promote smallholder cacao production in the buffer zone are explored: (1) cacao agroforestry is an ecologically benign agricultural system; (2) if cacao production were more financially viable, ecologically degrading activities, such as cattle grazing, would decrease; (3) migrants from other areas are primarily responsible for clearing land on the eastern side of the park; and (4) direct intervention at the smallholder level is the most effective means of preventing agricultural expansion. Our analysis demonstrates that while cacao agroforestry is an ecologically appropriate production system for the buffer zone of the park, price and production stabilization is important for assuring adoption by smallholders. We also suggest that both indigenous and migrant groups are responsible clearing forest for agriculture and that a more useful distinction for managers to make is between clearing enacted as part of sustainable vs. unsustainable management regimes. Finally, we recommend that the impact to the biosphere reserve caused by large-scale cattle and banana production not be overlooked.     

From Farmers to Loggers: The Role of Shifting Cultivation Landscapes in Timber Production in Cameroon

This article focuses on timber sourced from the agricultural areas in the shifting cultivation landscapes of the Central Region of Cameroon. Data about volumes marketed in urban centres, harvesting operations and on-farm timber management are used to discuss the ecological impact of small-scale logging and its sustainability in the long term. An opportunistic association exists between small-scale logging and agricultural land uses, determined mostly by the abundance of valuable species in fallows and on cocoa farms, their easy accessibility and the low price of farmland timber. Farmers apply various strategies to the management of tree resources in fallows and cocoa agroforests, with most felling authorized in fallows and most trees preserved on the cocoa farms. With current agricultural expansion and intensification trends associated with small-scale logging, timber resources on rural land are at risk of depletion with direct consequences for domestic timber supply and the thousands of livelihoods it sustains. Marketing and regulatory changes are needed to encourage the integration of timber production in agricultural management systems.     

Impact of Land Tenure Change on Land Use

China is a public ownership country. At present, theownership of land belongs to the country andcollectivity. In China, the meaning of ownership ofland is the light that the owners of land can possessthe land, use the land, get some interest from the landand deal with the land according to laws. The 4 sectionsof ownership of land can either be combined or beseparated to carry out. In practice, these 4 sections ofownership are usually separated to carry out. The tenureof land is an independent…     

The problem of irrigated horticulture: matching the biophysical efficiency with the economic efficiency

Modern irrigated horticulture provides society with a wide variety of quality produce at a cheap price. Set against this economic efficiency is the leakage of water and nutrients to the environment coupled with degradation of the resource base upon which future production depends. This paper illustrates why we might expect irrigated horticulture to spawn environmental problems related to excess water, excess nutrients and land degradation. The solutions to these problems will entail much more than just better management by farmers. If we cannot manage or engineer away the problems of irrigated horticulture, we must then address the very way the agro- ecosystem functions, in the areas of water and nutrient capture and soil management. This will require the design of new agricultural systems where the sources and sinks of water and nutrients are more evenly matched in time and space. This revised version was published online in June 2006 with corrections to the Cover Date.     

鄂西山地农林复合优化模式及效益评估

为减少坡耕地水土流失现状,提高种植经济收入,在秭归县九畹溪镇实施5种农林复合种植优化模式.以农作物作为对照,对这5种模式生长情况进行调查,同时对经济效益和生态效益进行评估.结果表明：①主要树种成活率在90％以上,保存率在85％以上,保存面积达100％;②从经济效益上来看,农林复合种植模式总收入远高于单纯农作物种植模式,进入盛产期后以核桃＋茶叶埂模式收入最高,未进入盛产期时以香椿 药材＋茶叶埂模式收入最高;③从生态效益来看,项目的实施每年平均可减少土壤流失532.61 t,年均径流量减少15 998.40 m3,全氮、全磷、有效钾年均流失量分别减少12.89,12.58,2.05 t.     

基于GIS技术的农用地等级评价方法研究

研究利用GIS技术,结合传统农用地等级评价方法,提出基于GIS技术的县域农用地等级评价方法.针对昭阳区农用地资源现状,综合分析影响农用地等级的各种因素,利用土壤图、土地利用现状图及行政区划图叠置划分法确定评价单元,选取土壤管理、立地条件、剖面与耕层理化性状、耕层养分状况、气候等5 个方面16个评价因子,建立农用地等级评...     

我国喀斯特石漠化地区林下经济种植模式及问题分析

由于我国喀斯特石漠化地区人地矛盾突出、林地与土地利用率低、森林生态系统破坏严重,改善喀斯特地区森林生态系统的经济功能、防控石漠化恶性演替仍是当下亟需解决的艰巨任务。林下种植是一种经典的立体复合林业生产经营方式,能够实现林地资源最大利用化、缓解人多地少的矛盾、推动区域经济循环可持续发展、保障林农经济效益稳步增长,最终达到林业经济、农业发展和生态建设同步优化的目标。文中主要分析了喀斯特石漠化地区8种代表性林下种植模式的特征、效益及不足,并提出各林下种植模式关于结构优化升级、调整改善方面的核心对策,以期为喀斯特地区石漠化治理与林业发展提供理论支持与借鉴,确保生态、经济、社会效益的同步优化。     

Practical Application of Multivariant Analysis Techniques to the Forest Management of Active Farmers in the Northwest of Spain

As managers almost exclusive in many worldwide forestry regions, non-industrial private forest (NIPF) owners come to play a key role in balanced integrating the variety of forest uses and functions in policies for promoting and revitalising rural areas. In Galicia, a region in the Spanish Northwest, over 67.5% of forestland and 80% of woodland is managed by NIPF owners. Almost 40% of the Galician NIPF owners are agricultural or livestock farmers who manage a total of 169,755 agrarian holdings with woodlands. Although the number of agricultural holdings has dropped significantly over the last 60?years, farmers still constitute a representative section of the NIPF owner population in Galicia. Starting from an initial population of 31,285 active full-time professional farmers in the region, and based on data collected by a personal questionnaire from a sample comprising 4,383 of these professional farmers for the period 1993?C2003, Discriminant Analysis (DA) was used to identify which socioeconomic, territorial and public-political factors were useful in distinguishing, and to what extent, that a certain population of Galician active farmers should opt to own and manage forestland areas within their agrarian holdings. The results suggested that the forestry production capacity for the area in which the agricultural holding is located, the size and the number of plots in the land base, the number of years the farmer has been the owner and the economic yield from the holding over the total family income were key factors in distinguishing between farmers with forestry activity (forestland owners) and farmers with no forestry activity (farmland owners). These findings could be used as a guide for designing, planning, and implementing research and policy measures that could allow NIPF landowners with farming and livestock activity to develop sustainable forestry, as key agents in promoting rural development.