清江水布垭水库农村移民安置区环境容量研究

清江是长江流出三峡之后的第一条大支流,发源于鄂西利川市,自西向东流经湖北省的１０个县（市）,于宜都市注入长江,在清江建设水布垭水电站是“流域,梯极,滚动,综合”开发利用清江水利资源的重要决策,将促进区域经济的发展。水布垭水库淹没涉及巴东,鹤峰,建始,宣恩,恩施５县（市）的陆地面积５５．４ｋｍ＾２,其中耕园地１１４７．８ｈｍ＾２。     

湖北省湖泊资源特点及开发利用

通过对湖北省境内主要湖泊（面积大于１０ｋｍ＾２）的调查与分析，阐述了湖泊资源的几个特点，探讨了湖泊资源利用中存在的问题，并就湖泊资源的合理开发利用途径提出了建议。     

汉江中下游江段藻类现状调查及“水华”成因分析

汉江是长江的最大支流,全长１５３２ｋｍ,年径流总量为５９１亿ｍ＾３,流域面积１５．１万ｋｍ＾２。汉江既是湖北省主要航道之一,又是沿岸居民生活用水和工业用水的重要水源。早在７０年代,汉江的水质一直符合地面水Ⅱ级标准,但自９０年代以来,汉江的水质逐年下降,并分别于１９９２年和１９９８年的初春先后两次发生硅藻大量繁殖。     

长江三峡花岗岩地区土壤流失时间分布特性

长江三峡花岗岩地区坡面土壤流失以耕地砂砾化面蚀和有部分植物覆盖坡面的鳞片状面蚀为主，该地土壤流失研究结果表明，由以上两类面蚀导致的土壤流失量月分布与月降雨量的分布基本趋势一致，二者呈现较为明显的线性相关关系。地面坡度＞３０°的裸地土壤流失量达５０００ｔ／ｋｍ３·ａ以上，覆盖度≥０．７０的林地土壤流失量＜５００ｔ／ｋｍ２·ａ，该流域土壤流失量为１５４４．１４ｔ／ｋｍ２·ａ，产沙量为６９４．８６ｔ／ｋｍ２·ａ     

三峡工程与长江中游浅层承压水动态

三峡水库正常运行后,坝下枯季下泄流量增加,将使荆江水位比建坝前抬高１－２ｍ。由于长江与两侧浅层承压水有着十分密切的联系。长江枯季水位升高将阻滞两岸地下水向长江排泄,从而使两岸承压水位相对抬高。观测研究表明,长江对承压水动态的影响程度随距离的增加而减弱,二者成分段线性反比的关系。在龙口观测剖面,如长江水位升高１ｍ,则在距离为０－１ｋｍ地段,承压水位将抬高１－０．２ｍ;在１－４ｋｍ地段,抬高０．２５－     

洞庭湖区湿地生态功能退化与避洪,耐涝高效农业建设

地处长江中游的洞庭湖是一个承纳湘、资、沅、澧四水和吞吐长江的洪道型湖泊,在其特殊的地理环境与碟形盆地圈带状景观结构控制下,形成了以敞水带、季节性淹没带、渍水低地为主的我国最大的湖泊地区湿地景观,湿地总面积８７．７０万ｈｍ＾２。由于湖区发展过程中没有协调好人地、人湖关系,中上游干支流水土流失加剧、湖泊泥沙淤积与过度围湖垦殖、高水位地段农业布局与种植制度不合理等人为因素导致湿地面积减少、调蓄能力下降,     

利用冬春气候条件发展长江中游大麦生产

大麦是世界四大谷类作物之一,以适应性强、抗塑性强、抗逆性好、用途广而在世界各大洲广为种植。二次世界大战后,随着经济发展,大麦产量由６０年代的９９７０．０万ｔ增加到１９９４年的１５８７２．８万Ｔ,长江 中游历来是我国大麦的主要种植之一,随着我国经济的发展,大麦生产经况愈下,成为我国进口量最大的农产品之一,其种植面积由１９６１年７７．９２７万ｈｍ＾２降为１９９５年的８．３４８万ｈｍ＾２,与世界经济越发     

可持续发展的理念正在变成现实——安徽省池州地区可持续发展的实践

池州地区位于长江南岸 ,安徽省西南部。国土面积 8391ｋｍ2 ,人口 1 5 2万 ,呈“七山半水分半田 ,一分道路和庄园”的自然格局。该地区建国后三建两撤 ,失去许多发展的机遇 ,工业欠发达 ,但生态环境非常好 ,境内处处山清水秀 ,树木郁郁葱葱 ,人和自然比较协调。良好的生态环境是池州地区最宝贵资源 ,是池州形象的反映 ,是发展生态经济的基础和优势。早在 1 988年池州地区重新组建时 ,地委、行署就明确提出“不会治山治水 ,就不会治区”的发展思路 ,并坚持治山治水不松懈。长期以来 ,地区经济的快速发展 ,不仅没有破坏生态环境 ,而且得到进一…     

苏南丘陵主要森林类型保持水土效益的研究

１９９１年度在苏南丘陵地区用径流小区法测得杉木林、火炬松林、栎林及裸地的地表径流系数分别为９．５５％、３８．９９％、６．０１％、４５．３７％。土壤侵蚀量分别为２８１．０ｔ／ｋｍ￣２、２２５．４ｔ／ｋｍ￣２、２３８。４ｔ／ｋｍ￣２、１４４１４．５ｔ／ｋｍ￣２。与裸地相比，森林保持水土的效益非常显著。文中还详细讨论了裸地的土壤侵蚀规律，并给出了裸地土壤侵蚀量的经验预报方程。     

试论清江流域的旅游资源与开发

试论清江流域的旅游资源与开发杨达源（南京大学大地海洋科学系南京２１０００８）清江系长江南侧较长的支流，源于川鄂边界的齐岳山、流经鄂西南利川、建始、恩施、宣恩、咸丰、巴东、五峰、长阳、宜都诸县市，总落差１４３０ｍ。清江流域总面积约１７０００ｋｍ￣２，全...     

Comparative analysis on financial viability of cocoa agroforestry systems in Ghana

This study employs an ex-ante analytical approach to explore the financial viability of cocoa agroforestry systems in Ghana using cross-sectional data on smallholder cocoa farmers in the Western Region of Ghana. The empirical results generally show that cocoa agroforestry systems are profitable, but the medium shade tends to be more profitable. The no-shade cocoa agroforestry has the highest yield compared with other cocoa agroforestry systems. Sensitivity analysis revealed that increasing the market price by 12.2 % tends to increase the profitability of cocoa agroforestry systems. Also increasing fertilizer price does not lead to any significant change in the profitability. The study recommends the medium-shade cocoa agroforestry system as the most profitable agroforestry system for optimizing ecological and economic outcomes of smallholder cocoa farmers in sub-Saharan Africa.     

Agroforestry in the Western Ghats of peninsular India and the satoyama landscapes of Japan: a comparison of two sustainable land use systems

Agroforestry in the Western Ghats (WG) of peninsular India and satoyama in rural Japan are traditional land-use systems with similar evolutionary trajectories. Some of their relevance was lost by the middle of the twentieth century, when modern agricultural technologies and urbanisation engineered shifts in emphasis towards maximising crop production. There has been, however, a resurgence of interest in traditional land-use systems recently, in view of their ability to provide ecosystem services. Both agroforestry and satoyama are thought to be harbingers of biological diversity and have the potential to serve as “carbon forests.” Carbon (C) stock estimates of the sampled homegardens in WG ranged from 16 to 36 Mg ha⁻¹. Satoyama woodlands owing to variations in tree stocking and management conditions indicated widely varying C stocks (2–279 Mg ha⁻¹). Agroforestry and satoyama also differ in nature, complexity, and objectives. While agroforestry involves key productive and protective functions, and adopts ‘intensive management’, the satoyama woodlands are extensively managed; understorey production is seldom a consideration. Differences in canopy architecture (multi-tiered structure of agroforestry vs. the more or less unitary canopy of satoayama) and land ownership pattern (privately owned/managed agroforestry holdings vs. community or local government or privately owned and mostly abandoned satoyamas) pose other challenges in the transfer and application of knowledge gained in one system to the other. Nonetheless, lessons learnt from satoyama conservation may be suitable for common pool resource management elsewhere in Asia, and aspects relating to understorey production in agroforestry may be relevant for satoyama under certain scenarios.     

Dynamics of leaf litter and soil respiration in a complex multistrata agroforestry system,Pernambuco, Brazil

High litter inputs in agroforestry systems contribute to soil microbial activity, soil fertility and productivity. Considering that the cycling of organic matter is essential to the maintenance of physical–chemical and microbiological properties of the soil, the aims of this work were to estimate the production, accumulation and decomposition of litter, and assess soil microbial respiration in a complex multistrata agroforestry system located in the north-east of Brazil. This agroforestry system has three strata formed by forest and fruit trees and species of multiple uses. During 3 years (2011–2013), leaf litter was sampled monthly to account for litterfall and quarterly to account for litter accumulation. The rates of litter decomposition were estimated using the ratio produced-to-accumulated litter, and the correlation between litter fall and rainfall was calculated. Precipitation data were provided by the water and climate agency of Pernambuco (APAC). Soil samples (0–15 cm) were also taken quarterly, simultaneously with the litter accumulation samples, and soil microbial respiration was assessed using the capture, by a KOH solution, of the evolved CO₂. The annual production of leaf litter was stable in the 3 years of study in this agroforestry system, and the monthly input of litter to the soil was influenced by rainfall, being higher in the dry seasons. The accumulated litter on the ground was constant, as was microbial activity (respiration) through time. The estimated litter decomposition rates were 1.49 (first year), 1.33 (second year) and 1.42 (third year), being considered rapid rates of decomposition. This guarantees (to the farmer) that this system is capable of maintaining soil fertility and eliminates the need for chemical fertilizers.     

Vulnerability of wild indigenous agroforestry species to climate change in Niger State,Nigeria: A proxy analysis

Environment, Development and Sustainability - This study assessed the vulnerability of five indigenous agroforestry trees to climate change: Adansonia. digitata, Vitellaria paradoxa, Parkia...     

Delivering on the Promise of Agroforestry

Agroforestry – the traditional practice of growing trees on farms for the benefit of the farm family and for the environment – was brought from the realm of indigenous knowledge into the forefront of agricultural research less than two decades ago. It was promoted widely as a sustainability-enhancing practice that combines the best attributes of forestry and agriculture. Based on principles of natural resource management and process-oriented research, agroforestry is now recognized as an applied science, that is instrumental in assuring food security, reducing poverty and enhancing ecosystem resilience at the scale of thousands of smallholder farmers in the tropics.Trees on farms provide both products and services: they yield food, fuelwood, fodder, timber and medicines, which farm families can use at home or take to market to bring in much-needed cash; they replenish organic matter and nutrient levels in soils and they help control erosion and conserve water. The International Centre for Research in Agroforestry, and its partners, are working to integrate the functions of trees with policy and institutional improvements that aim at facilitating wide-scale adoption by farmers.Two examples described in this paper are replenishing soil fertility in sub-Saharan Africa using short-term improved tree and shrub fallows and the results of agroforestry research to support significant land tenure policy in southeast Asia.Although just one option in sustainable land-use, science-based agroforestry has the potential to produce economically, socially and environmentally sound results for the billions of people who depend on this ancient practice and modern science.     

Agroforestry environment,potentiality and risk in India: a remote sensing and GIS understanding

Environment, Development and Sustainability - The study utilized the tree covers per cent, agroforestry suitability, present and future (2050) climate, agriculture vulnerability (2050), percentage...     

GHG Mitigation Potential and Cost in Tropical Forestry - Relative Role for Agroforestry

This paper summarizes studies of carbon mitigation potential (MP) and costs of forestry options in seven developing countries with a focus on the role of agroforestry. A common methodological approach known as comprehensive mitigation assessment process (COMAP) was used in each study to estimate the potential and costs between 2000 and 2030. The approach requires the projection of baseline and mitigation land-use scenarios derived from the demand for forest products and forestland for other uses such as agriculture and pasture. By using data on estimated carbon sequestration, emission avoidance, costs and benefits, the model enables one to estimate cost effectiveness indicators based on monetary benefit per t C, as well as estimates of total mitigation costs and potential when the activities are implemented at equilibrium level. The results show that about half the MP of 6.9 Gt C (an average of 223 Mt C per year) between 2000 and 2030 in the seven countries could be achieved at a negative cost, and the other half at costs not exceeding $100 per t C. Negative cost indicates that non-carbon revenue is sufficient to offset direct costs of about half of the options. The agroforestry options analyzed bear a significant proportion of the potential at medium to low cost per t C when compared to other options. The role of agroforestry in these countries varied between 6% and 21% of the MP, though the options are much more cost effective than most due to the low wage or opportunity cost of rural labor. Agroforestry options are attractive due to the large number of people and potential area currently engaged in agriculture, but they pose unique challenges for carbon and cost accounting due to the dispersed nature of agricultural activities in the tropics, as well as specific difficulties arising from requirements for monitoring, verification, leakage assessment and the establishment of credible baselines.     

Creating an academic landscape of sustainability science: an analysis of the citation network

Sustainability is an important concept for society, economics, and the environment, with thousands of research papers published on the subject annually. As sustainability science becomes a distinctive research field, it is important to define sustainability clearly and grasp the entire structure, current status, and future directions of sustainability science. This paper provides an academic landscape of sustainability science by analyzing the citation network of papers published in academic journals. A topological clustering method is used to detect the sub-domains of sustainability science. Results show the existence of 15 main research clusters: Agriculture, Fisheries, Ecological Economics, Forestry (agroforestry), Forestry (tropical rain forest), Business, Tourism, Water, Forestry (biodiversity), Urban Planning, Rural Sociology, Energy, Health, Soil, and Wildlife. Agriculture, Fisheries, Ecological Economics, and Forestry (agroforestry) clusters are predominant among these. The Energy cluster is currently developing, as indicated by the age of papers in the cluster, although it has a relatively small number of papers. These results are compared with those obtained by natural language processing. Education, Biotechnology, Medical, Livestock, Climate Change, Welfare, and Livelihood clusters are uniquely extracted by natural language processing, because they are common topics across clusters in the citation network.     

南方红壤丘陵区的农业景观特征与农业布局

分析了南方红壤丘陵区农业景观特征,提出该区重点治理的生态脆弱带为低丘岗地,认为该地带的人为干扰和自然作用不相协调是本区农业景观的不良演替的原因。初步探讨了通过农业合理布局,促进该区景观恢复的途径。指出作物布局和土壤耕作对低丘岗地保护、开发及景观恢复等方面的意义。     

资源工程体系建设探讨——以三峡库区坡地资源开发保护体系建设为例

资源工程是实现社会经济发展的基本途径。资源开发体系和保护体系建设是构成资源工程体系的主要内容。文章阐述了如何设计一个资源开发和保护体系的总体思路（包括原则、目标、内容、行动、效益评估）,并以长江三峡库区坡地资源利用保护为例,通过植物篱农林复合技术,使水土流失和环境退化基本得到了控制,经济产出比纯柑桔系统和纯粮食作物系统分别高出１／５和１／４,成为开发与保护融为一体、经济和生态相互促进的技术。这一技术值得在中国东部湿润半湿润区域推广。