Ecological properties of soil water and effects on forest vegetation in the Loess Plateau

In the Loess Plateau of China, soil water has three ecological properties: high infiltration capacity, high storage capacity and availability to deep plant roots. Soil desiccation is the most serious problem for forest vegetation in the Loess Plateau. Arid soils are the result of intensified soil desiccation caused by disturbances in plant succession, which constitute the ecological foundation of soil water. The negative effects of the arid soil layer on surface water infiltration for recharging underground water are discussed in terms of ecological hydrology. The arid soil layer disrupts the link between surface water and underground water and prevents vertical precipitation infiltration from supplementing underground water. Forest vegetation has a significant runoff-retaining efficiency that reduces total runoff from forest areas leading to low surface and ground runoff which affect the water cycle on a watershed scale.     

Integrated effects of slope aspect and land use on soil nutrients in a small catchment in a hilly loess area,China

This study addressed the integrated effect of slope aspect and land use on soil nutrients in a loess hilly catchment in the western Loess Plateau of China. Soil samples were collected from five land-use types: wasteland, cropland, woodland, shrubland and abandoned cropland, at two depths (0–20 and 20–40 cm) in the middle slope position of both north-facing and south-facing slopes. Soil nutrient changes and the relationships between soil nutrients and slope aspect were investigated, based on statistical analysis and expert knowledge. Soil organic matter, total N, total P, nitrate nitrogen and available K of the 0–20 cm soil layer differed significantly between land uses and slope aspects. Soil nutrients in the north-facing slope were better than in the south-facing slope. Revegetation has an enrichment effect, especially on soil organic matter, total N, total P, nitrate nitrogen and available K. Planting of trees, shrubs and grasses could improve soil fertility and favours a policy of revegetation and sustainable land use in the hilly loess area of China. Conversion of slope farmlands into more sustainable land uses, such as shrubland or grassland is a cost-efficient way to achieve soil conservation and ecological restoration. Terracing and the use of agro-techniques for soil conservation, such as furrow-ridging tillage and leaving crop residues on fields, can increase the input of C to soils. Growing crops in rotation with alfalfa and beans could be a promising choice for the sustainability of agriculture and the environment.     

Soil surface nitrogen losses from agriculture in India: A regional inventory within agroecological zones (2000–2001)

We present soil surface nitrogen (N) budgets for the agricultural sector of India, calculated as inputs minus outputs over 21 agroecological zones (AEZ), for 2000–2001. Nearly 35.4 Tg N was input from different sources, with output from harvested crops of about 21.2 Tg N. Soil surface N balance for agricultural lands showed a surplus of about 14.4 Tg. Livestock manure constituted 44% of total inputs, followed by 32.5% from inorganic fertilizer, 11.9% from atmospheric deposition and 11.6% from N fixation. Though the N balance was negative in some states, due to aggregation of states in agroecological regions, all regions showed surplus N loads, with a range of about 19–110 kg/ha. The lowest loads were found for AEZ 17 in the Eastern Himalaya, with 19 kg/ha surplus, and the highest surplus N load in AEZ 7 with 111 kg/ha in Deccan plateau and the Eastern Ghats. Temporal trends in fertilizer consumption from 1950–2000 for India suggested a massive increase of ～47-fold, whereas production of major crops, rice, wheat and maize, increased nearly ～4.0-, 10- and 6-fold, respectively. Fertilizer consumption patterns were highly concentrated in Tamilnadu (204.6 kg/ha), Haryana (132.0 kg/ha) and Punjab (148.6 kg/ha). The paper addresses the role of agricultural intensification and its implications for water quality in agroecological regions of India.     

Sustainable poverty alleviation through a forestry project in Tamilnadu State of India

The World Development Report 2000–2001 recommends action on three complementary and synergistic fronts for poverty alleviation – promoting opportunity, facilitating empowerment and enhancing security. This paper analyses the Tamilnadu Forestry Project, funded by US$100 million from the Japan Bank for International Cooperation, for community forestry. The project was launched in 1997–1998 in this southern state of India and has evolved into a comprehensive poverty alleviation programme for the forest abutting villages where the proportion of poor people is largest. It endeavours to explain how the project provides the above three elements at the local level for sustainable poverty alleviation. Regeneration of forests, improvement of basic infrastructure through integration of line departments and promotion of alternate livelihoods provide ample economic opportunities. Establishment of Village Forest Councils, and delegation of sufficient powers to these Councils, has empowered the poorest of the poor. Tree assets, promotion of alternate income generation activities and water harvesting structures have provided security by reducing vulnerability to natural vagaries, particularly drought. In this project, the restoration of biodiversity and people development go hand in hand in a synergistic way that makes the project worth replicating elsewhere in the country and other parts of the world, with suitable modifications.     

Forest fragmentation in the Himalaya: A Central Himalayan case study

Administrative divisions in the Great Southern Watershed of the Himalaya are diverse in terms of population density and forest cover. This study analyzed the spatial patterns of different attributes in the different Indian states and Himalayan kingdoms, and explored the extent and patterns of forest fragmentation in a Himalayan landscape as a case study. Of the total landscape in the case study area (3167 km²), 41% was fragmented. Homogenous landscape (59%) includes either continuous natural vegetation or a village landscape. Presence of two forest patches (38% of the total fragmented area) at a unit scale of about 0.5 km² (525 × 525 m) was the most commonly occurring pattern but, in some parts, up to 13 patches were observed. Fragmentation of vegetation was visible even at smaller scales of landscape analysis. At a scale of 75 × 75 m, land division into three patches was observed. With an increase in the unit area of landscape analysis the number of patches per unit land area and the total fragmented area also increased. The forests that escaped fragmentation were either inaccessible to humans or had rigorous legal protection. Anthropogenic activities appeared to be one of the factors responsible for fragmentation but, natural factors also contributed.     

Integrated water resource management at the industrial park level: A case of the Tianjin Economic Development Area

Water reuse and wastewater minimization are becoming increasingly important strategies for industrial parks. However, integrated industrial water management systems at an industrial park level have not yet been adequately investigated to determine synergies. This paper employs a case study of the Tianjin Economic Development Area (TEDA) to examine the importance of developing an integrated water resources management framework at the industrial park level. The paper presents a framework for effective and efficient management of water resources within an industrial park by taking a systems approach to conventional water management practices, designed to minimize industrial water use and maximize wastewater reuse among different tenants of an industrial park. The framework is composed of four elements: a management information system, policies and regulations, economic instruments and capacity building. The paper then considers how to implement such an integrated approach.     

Eco-Environmental benefit assessment of the western route in China's South-North Water Transfer Project

Assessing the benefits of China's South-North Water Transfer project (SNWT) requires successful integration of an analysis of economic and eco-environmental benefits (EEB). To attain such integration, it is necessary to assess the EEB in detail, after the economic benefits have also been thoroughly assessed. The shadow engineering and market value methods are the major EEB assessment methods used in this study. We have assessed the EEB of the forest and grassland ecosystems in the recipient regions of the Western Route Project (WRP) for 2020, 2030 and 2050. Finally, some proposals are also made for efficient and sustainable management of the WRP.     

Indigenous practices for harvesting water from streams in the semi-arid environment of Nepal

Techniques for water harvesting from streams for irrigation and waterpower utilities, particularly in the semi-arid middle mountain region of Nepal, were developed many centuries ago. Water harvesting techniques have traditionally evolved to fit the local environment and living conditions of the people. In terms of community participation, the sustainability of community-based local water resources management in Nepal should promote traditional streamwater harvesting technologies that will potentially benefit local communities and also should be recognized by environmentalists and water experts. This paper investigates some traditional forms of water delivery technologies adopted by local farmers in three catchment areas from the middle mountain region of Nepal. Each form of indigenous practice is considered from the objective of scientific validation.     

Gender roles and economics of exploitation,processing and marketing of bivalves and impacts on forest resources in the Sanaga Delta region of Douala-Edea Wildlife Reserve,Cameroon

Socio-economic surveys were carried out in the Malimba and Mouanko communities in the Sanaga delta region of the Douala-Edea Wildlife Reserve, Cameroon, on the exploitation, processing and marketing of bivalves, with emphasis on gender aspects and impacts on the surrounding forest resources. Sixty people from 16 villages were sampled using a structured questionnaire with field observations documented during the peak fishing period (November 2000–June 2001). Results indicated a strong gender differentiation in the activity, with males dominating bivalve harvesting and shell processing and women dominating the processing for meat. Monthly bivalve meat production of 32.9 tons (197.4 tons per year) generated revenues of 65.4 million FCFA (74.9 million per year). Monthly shell production was put at 1380 tons (8040 tons per year) generating a monthly revenue of 74 million FCFA (444 million per year). Problems faced during exploitation, processing and marketing stages include physical, health and socio-economic: use of very depreciable rudimentary tools, shell injuries, fire and hot water burns, insect pests; blindness, deafness; inadequate storage facilities, transport and remoteness of the area. Bivalve processing activities using wood contributed to a total annual harvest of 50 986 m³ from the surrounding forest. Sustainable conservation measures geared towards poverty alleviation are proposed.     

Farmer's perception and response towards land policy and eco-environment based on participatory rural appraisal: A case study in the Loess hilly area,China

Based on a survey of 107 farm households by means of participatory rural appraisal, this paper presents a region-level analysis of farmer's perception and response towards land policies and eco-environment in the Loess hilly area, China. The surveyed farmers are divided into two groups, farmers on non-irrigated farmland and farmers on irrigated farmland. The results indicate that most farmers mainly depend on cropland, especially the farmers on non-irrigated farmland. Farmers believe that stability and persistence of land policies are important, and most hold a positive attitude towards the Grain-for-Green Programme. The farmers on irrigated farmland have a more favourable attitude to environmental conservation than the farmers of non-irrigated farmland. Nearly 80% of interviewees consider that the local eco-environment has improved in the last ten years. About 45% never consider the environmental impact of their agriculture practices. About 55% think drought is the most important reason for eco-environment deterioration, overgrazing and serious soil erosion. Soil and water conservation is not conscious and voluntary behaviour for farmers, it is only a measure to guarantee their basic agricultural production and to improve their living conditions. Results indicate that farmers on nonirrigated land find engineering approaches more beneficial to agronomic methods. However, the farmers on irrigated farmland pay more attention to improving farmland quality.     

Simulating the impacts of land-use changes on non-point source pollution in Lugu Lake watershed

Protection of the water quality of Lugu Lake is important because it is a unique geographic and cultural resource. Not only point source pollution but also non-point source pollution contribute to degradation of water quality. A GIS-NPS model, with long-term hydrologic impact assessment (L-THIA), was used to evaluate long-term implications of land-use change impacts on non-point source (NPS) pollution. The land-use patterns of 1995 and 2005 were analysed to determine the changes in Lugu Lake watershed. A 30-year (1974–2003) precipitation dataset was used to estimate mean annual surface runoff and NPS pollutant loads. The contributions of different land-use categories to average annual runoff and NPS pollutant production were assessed with a unit contribution index (UCI). Results show loss of agricultural land (by 44.9%), while forest, grass/pasture and residential land increased to different degrees from 1995 to 2005. At the same time, annual average NPS pollutants, TN, TP, TSS and BOD loads all decreased, while heavy metal lead increased by 6.87%. The UCI formulated in this research was a more useful method to assess land-use impact on NPS pollutants than simple investigations of the percentage land-use change. Agricultural and residential land changes had more impact on NPS pollutants and were identified as the main source types. Suggestions on regulating land uses and management proposals for protecting lake water quality in Lugu Lake watershed are made.     

Participatory assessment of soil degradation in the uplands of southwestern Tanzania: Implications for sustainable agriculture and rural livelihoods

Rural household food insecurity and poverty are closely linked to soil degradation in Sub-Saharan Africa. However, causes, degradation processes, coping strategies and need for interventions may vary from one place to another. This study was conducted in Mbinga District, SW Tanzania, to investigate causes and biophysical processes of soil degradation; effects on livelihoods, coping strategies and entry points for interventions. Implications for sustainable production and rural livelihoods are discussed. Participatory Rural Appraisal (PRA), household surveys using a short open-ended questionnaire and biophysical exploration were the research tools used. Soil fertility depletion resulting from continuous cropping and erosion losses is the main form of soil degradation. Maize yield was 57% lower in fertility-depleted farms than in productive farms. Soil pH, Ca²⁺, Mg²⁺ and CEC accounted for 79% of variations in maize yield. Organic soil fertility amelioration was a common strategy used by smallholders. Use of beneficial tree and shrub fallows is the most environmentally, economically and socially promising improvement that can be used to build on the existing strengths of farmers' knowledge and strategies. Subsidy for the right type of fertilizers, infrastructure improvement and education of farmers on proper use of fertilizers should significantly contribute to improved and sustainable production and livelihoods.     

Impact of population growth and land-use change on water resources and ecosystems of the arid Tarim River Basin in Western China

Time series data on population change, economic development, climate change, water volume and quality and oasis land-use change were collected to study the interactions between these factors in the arid Tarim River Basin, China. The study reveals that precipitation and stream flow in headwater streams increased, but stream flow in the main Tarim River had reduced significantly over the past three decades. This implies that human activity, rather than climate change, dominated the recent environmental changes in the river basin. As a result of population growth and cultivated land expansion in the upper and middle reaches of the river, severe problems of water shortage, water pollution, death of natural vegetation, soil salinization, desertification and sand-dust storms have occurred, particularly in downstream areas of the river basin. These problems have had serious negative effects on the health of local people and sustainable social economic development in the region. Some development strategies are proposed to deal with these problems.     

Predicting the time needed for environmental systematic reviews and systematic maps

Systematic reviews (SRs) and systematic mapping aim to maximize transparency and comprehensiveness while minimizing subjectivity and bias. These are time-consuming and complex tasks, so SRs are considered resource intensive, but published estimates of systematic-review resource requirements are largely anecdotal. We analyzed all Collaboration for Environmental Evidence (CEE) SRs (n = 66) and maps (n = 20) published from 2012 to 2017 to estimate the average number of articles retained at each review stage. We also surveyed 33 experienced systematic reviewers to collate information on the rate at which those stages could be completed. In combination, these data showed that the average CEE SR takes an estimated 164 d (full-time equivalent) (SD 23), and the average CEE systematic map (SM) (excluding critical appraisal) takes 211 d (SD 53). While screening titles and abstracts is widely considered time-consuming, metadata extraction and critical appraisal took as long or longer to complete, especially for SMs. Given information about the planned methods and evidence base, we created a software tool that predicts time requirements of a SR or map with evidence-based defaults as a starting point. Our results shed light on the most time-consuming stages of the SR and mapping processes, will inform review planning, and can direct innovation to streamline processes. Future predictions of effort required to complete SRs and maps could be improved if authors provide more details on methods and results.     

Secondary metabolites of the leaf surface affected by sulphur fertilisation and perceived by the cabbage root fly

Summary. Surrogate leaves treated with methanolic leaf surface extracts of Brassica napus L. (cv Express) plants that received three different sulphur fertilisation treatments showed even more marked differences by the oviposition choice of Delia radicum L. than the potted plants. This confirms that the oviposition preference of D. radicum is mediated by chemical compounds on the leaf surface and that the quality of host-plants in terms of their nutrition status can be perceived by the female insect.The oviposition data were positively correlated with the content of fractionated surface extracts containing either CIF (cabbage identification factor; 1,2-dehydro-3-thia- 4,10,10b-triaza-cyclopenta[.a.]fluorine-1-carboxylic acid) or glucosinolates. Electrophysiological recordings from the tarsal chemoreceptor sensilla C₅ and D_3,4 showed that receptor neurons react to glucosinolate- and CIF-fractions. We found that the chemosensory activity of specific glucosinolate- and CIF-receptor neurons corresponded with the respective behavioural activity in the oviposition choice assays. The responses of D. radicum to glucosinolates in the electrophysiological recordings studies corresponded to the observed oviposition preference on plants or artificial leaves characterised with an higher amount of glucosinolates on leave surfaces. The presented data suggested that CIF and glucosinolates are involved in host-plant preference of D. radicum and are perceived by tarsal chemoreceptors.     

Degradation of diuron by the electro-Fenton process

The degradation of the herbicide diuron has been undertaken by electrochemical advanced oxidation in aqueous solution. This process generates catalytically hydroxyl radicals that are strong oxidizing reagents for the oxidation of organic substances. Hydroxyl radicals degrade diuron in less than 10 min. Kinetic results evidence a pseudo-first-order degradation, with a rate constant of reaction between diuron and hydroxyl radicals of 4.8x10⁹ M^–1 s^–1. Several degradation products were identified by chromatography-mass spectrometry (LC-MS). The mineralization degree of a 1.7x10^–4 M diuron solution reached 93% at 1,000 coulombs.     

Degradation of the herbicide imazapyr by Fenton reactions

The degradation of the herbicide imazapyr has been carried out by three advanced oxidation processes involving iron ions as catalysts: Fentons reagent, photo-Fenton and electro-Fenton. We show that all processes are rapid and efficient. The kinetic rate constant was found to be k=5.4×10⁹ M^–1 s^–1. The mineralization of imazapyr is almost complete using the photo-Fenton and electro-Fenton processes.     

生物接触氧化处理微污染地面水的实验研究

生物接触氧化处理微污染地面水的实验结果表明,该方法处理效果显著、稳定性好、操作方便、容易实施,是解决污染给水处理问题的经济可行办法。     

Postcopulatory mate guarding by vocalization in the Formosan squirrel

The Formosan squirrel, Callosciurus erythraeus thaiwanensis, emitted different vocalizations in response to terrestrial and aerial predators and snakes. Each vocalization caused nearby individuals to adopt a different type of anti-predator behaviour. In mating bouts, males produced two types of loud calls: precopulatory calls, emitted before copulations, and postcopulatory calls, emitted after copulations. The latter continued for 17 min on average. The estrous female and other males attending the mating bouts stopped moving during the postcopulatory call, so that the calling male was able to tend the female without interruption. The sound characteristics of anti-terrestrial-predator and postcopulatory calls recorded in the captivity were compared, and none of the ten characters of duration and frequency measured differed between the two calls. Playback experiments also showed that responses to the sounds in two different contexts, escape behaviour and defensive immobility, did not differ. The similarity between anti-predator and postcopulatory calls is discussed with reference to the possibility of manipulation and other explanatory hypotheses.     

生物膜法处理养殖废水的研究

室内模拟研究生物膜法处理养殖废水的效果及其影响因素。实验结果表明，连续曝气或者不曝气，生物膜法对养殖废水中的硝酸盐氮去除效果都很差。曝气条件下生物膜法对CODCrNH4^ -N、NO2^--N均有较好的净化效果，CODCrNH4^ -N、NO2^--N的去除率可分别达到79％、99％、99％；不曝气条件下生物膜法对CODCrH4^ -N、NO2^--N净化效果稍差，CODCrNH4^ -N、NO2^--N的去除率可分别达到78％、35％、76％。曝气会增加养殖废水中PO4^3 -P的质量浓度，增幅可达82％；不曝气时PO4^3 -P的去除率可达63％。投加复合菌株有利于生物膜的形成和处理效果的提高。