Researching the agroecosystem/environmental interface

This special issue of Agriculture, Ecosystems and Environment recognizes the important contribution of Dr. J.W. Sturrock to agroecosystem and environmental research through his long-term role as Editor-in-Chief (1982–2000). An historical overview of agroecosystem and environmental research is provided to illustrate the continued growth of scientific endeavor in this area, and to show its importance for a better understanding of ecological interactions within agroecosystems and especially at the agroecosystem/environmental interface. The papers collected in this special issue are selected to illustrate the breadth and diversity of agroecosystem and environmental research. They can be placed in the following four areas: the environmental impact of farming systems; the management of organic resources, the link between the ecology of farming systems and the environment; and the ecological interactions that occur within or between agricultural systems. Intensification of food production, population growth, technological change, changing land-use patterns, and global change will further impact the structure and functional properties of agroecosystems, and intensify the interaction between agriculture and the environment, and will present a major continuing need for research in the 21st century.     

Agroecosystem functional assessment and its difficulties

Agroecosystem functional assessment indicators provide a necessary bridge between decision-makers and scientists. The development of acceptable indicators, however, remains a difficult task because the current knowledge and understanding of ecosystems is not sufficient to allow an objective assessment of all ecosystem functions. These difficulties were summarized from three perspectives. First, there are difficulties in individual function assessment. Of the four functions associated with agroecosystems-energy flow, materials cycling,information flow and value flow-data on material cycling and information flow remain difficult to obtain and the indicators relatively immature. Secondly, there are difficulties of integration. During the assessment process, the integration of the agroecosystem functions remains the biggest obstacle. Until now, there has been no practical or effective methodology established to resolve the problem. At present, the makeshift approach has been to weight the various indicators and then add them together. Thirdly, there is the problem of obscure concepts and concept confusion. When assessments of agroecosystems are conducted, concepts such as structure, function, benefit,and resource utilization are used extensively. To date, no logical relationship (either real or implied) has been developed between any of these concepts. Are they causes and results such that the relationship between them is linear, or are they independent from one another such that the relationship is parallel? Thus far, the essence of this question is yet to be explored.     

Agroecosystems stability in the argentine pampas

Consideration of yield stability seems to be especially relevant to agroecosystems that are exposed to environmental perturbations. Improved knowledge about agroecosystem structures and functions and their relationships to the surrounding environment is required. The three main purposes of this work were: (a) to improve knowledge about some ecosystem structures and functions; (b) to evaluate their effects on productivity and yield stability; (c) to consider the design of low cost alternatives to optimize output and minimize risk. By means of a time-sequence analysis, 145 productive periods each with an average duration of 14 consecutive years were considered. Yield oscillation along each time sequence offers an acceptable stability index for the analysed activities. By converting outputs to energy units, the yields and stabilities of different production activities were compared. Results indicate that environmental gradation of the Pampas region affects primary production of herbage and grain more than secondary production of milk and meat, and this effect increases as the environment becomes more restricted. Some combinations of farming activities and energy pathways appear to affect agroecosystem productivity and stability simultaneously. The role of diversification of activities as a tool for agroecosystem stabilization is analysed, and some results are presented. Finally, the perspectives of this agroecological approach to improve system designs and its adaptation to particular regional constraints, are discussed.     

Responses of plant, insect and spider biodiversity to local and landscape scale management intensity in cereal crops and grasslands

The aim of this study was to determine the relative effects of landscape scale management intensity, agroecosystem type, local management intensity and edges on diversity patterns of functional groups of plants, carabid beetles, spiders and grasshoppers. Nine landscapes were selected differing in percent intensively used agricultural area (IAA), each with a pair of organic and conventional winter wheat fields and a pair of organic and conventional mown meadows. Within fields, plants were surveyed in the edge and in the interior. Carabid beetles and spiders were captured by funnel traps, while grasshoppers were sweep-netted in the meadows. Diversity patterns of study organisms were affected both by local variables (local management, agroecosystem type and within-field position) and by landscape scale management intensity. Species richness of grasses, presumably because of sowing low-diversity mixtures, and hunting spiders decreased with percent cover of IAA. Meadows differed from wheat fields in that they had higher species richness of forbs and grasses, as well as higher densities of hunting spiders. In contrast, more carabid individuals, especially of non-carnivore species, were captured in wheat fields. In field edges with their reduced management intensity and increased immigration, species richness of plants, carabids and spiders was higher than in the interiors regardless of agroecosystem type and management. Organic management enhanced forb richness and cover in both agroecosystem types. Organic management also increased grass cover in wheat fields, but not in meadows, and promoted species richness of non-carnivore carabids and hunting spiders, but not grasshoppers. The results show that agri-environmental management needs to be targeted to the agroecosystem's field size, because higher edge area led to higher species richness. Organic management affected several functional groups positively (forbs, non-carnivore carabids, hunting spiders), while lower landscape scale management intensity only increased species richness of grasses and spiders. The great differences in responses of functional groups to local cereal and grassland as well as landscape management suggest implementing more scale and group specific targets for agri-environmental schemes to improve their efficiency.     

Agricultural activities affecting the functions and values of Ramsar wetland sites of Greece

Agricultural activities in the agroecosystems neighbouring wetland ecosystems are considered a major threat to the latter in all Mediterranean countries. This threat was investigated in thirteen internationally important wetland sites (Ramsar sites) of Greece. The effects of ten activities commonly practised in the surrounding agroecosystems on four wetland functions and four wetland values were evaluated. The functions were: nutrient removal/transformation, sediment/toxicant retention, flood flow alteration, and ground water discharge. The values were: biodiversity, fishing, hunting, and recreation. It was found that the Adamus' Wetland Evaluation Technique is useful even in the little studied Ramsar sites of Greece. Irrigation is the most decisive activity negatively influencing all functions and values, followed by cropland expansion and overgrazing. Coastal lagoons are the least affected by agricultural activities. It is concluded that in Greece the sustainability of wetland ecosystems depends to a significant degree on the sustainability of agroecosystems. The reverse is also true because wetlands provide irrigation water, crop pollinators, some frost protection, and predators of crop pests. The two ecosystem types are functionally closely linked. Therefore, a national policy for the sustainable development of the soil, water, and genetic resources of Greece must integratively consider both these ecosystems types.     

The importance of scientific literacy in fostering education for sustainability: Theoretical considerations and preliminary findings from a Brazilian experience

Scientific literacy can be considered as a new demand of post-industrial society. It seems necessary in order to foster education for sustainability throughout students' academic careers. Universities striving to teach sustainability are being challenged to integrate a holistic perspective into a traditional undergraduate curriculum, which aims at specialization. This new integrative, inter- and transdisciplinary epistemological approach is necessary to cultivate autonomous citizenship, i.e., that each citizen be prepared to understand and participate in discussions about the complex contemporary issues posed by post-industrial society. This paper presents an epistemological framework to show the role of scientific literacy in fostering education for sustainability. We present a set of 26 collaborative concept maps (CCmaps) in order to illustrate an instance of theory becoming practice. During a required course for first-year undergraduate students (ACH 0011, Natural Sciences), climate change was presented and discussed in broad perspective by using CCmaps. We present students' CCmaps to show how they use concepts from quantitative and literacy disciplines to deal with the challenges posed by the need of achieving a sustainable development.     

吉林省循环农业发展的研究

吉林省是农业大省,农业要实现持续发展,很重要的是资源的可持续利用,发展循环农业能以最小的成本获得最大的经济效益和生态效益,对于吉林省改善农村生产、生活、生态环境有着非常重要的作用和意义。本文阐述了循环农业的概念及基本原则,分析了吉林省农业经济现状,并根据吉林省自身农业特点,并从推进工农业复合循环经济、发展生态农业、建设农业循环经济示范园区等三方面提出吉林省循环农业发展的方向,最后提出发展循环农业相关建议。     

DEM格网尺度对AnnAGNPS预测山地小流域径流和物质输出的影响

为了解流域地形空间参数和其它参数的精度对农业非点源污染模型AnnAGNPS预测准确性的影响,利用三峡库区黑河小流域观测资料校准了AnnAGNPS模型,分析了1.5-12.5m格网尺度DEM对地形参数和模型负载输出的影响.结果表明,1.5～12.5m格网尺度DEM对流域径流量、洪峰流量、总N输出影响不显著,但对泥沙、总P、有机碳输出影响显著.三峡库区类似小流域宜采用5m格网尺度DEM,AnnAGNPS模型较不适合于尺度较小、坡度较大的小流域泥沙负载预测.     

A review: long-term effects of agricultural systems on soil biochemical and microbial parameters

This paper provides a review of recent developments on assessing the effect of agricultural systems on long-term productivity of soils. Cultivation of soils, besides affecting soil chemistry and structure, reduces biological activity due to the reduction of macroaggregates which provides an important microhabitat for microbial activity. Indirect evidence suggests that soil amendments such as animal and green manures, and plant diversity (crop rotations) may be more important in maintaining soil microbial activity/diversity than conservation tillage in monocultural systems. There is increasing evidence that crop rotation promotes crop productivity by suppressing deleterious microorganisms that flourish under monoculture. Additions of inorganic fertilizers can increase soil biological activity because of an increased plant biomass production which upon incorporation stimulates soil biological activity. Conversely, limited evidence suggests that repeated applications of inorganic fertilizer nutrients can suppress production of certain soil enzymes that are involved in cycling of a given nutrient. The observed transitory decrease in crop productivity during conversion from chemical intensive input to alternative systems (greater reliance on biological resources) may be due to the initial diminished biological potentials of conventionally managed soils to efficiently cycle and mineralize organic nutrient sources. This review reaffirms the continuing need for the maintenance of existing long-term experimental sites and establishment of new studies in major agroecosystems throughout the world.     

Scientist and stakeholder perspectives of transdisciplinary research: Early attitudes,expectations, and tensions

Transdisciplinary approaches are becoming increasingly adopted as a way to research complex socio-environmental problems. Conceptually, transdisciplinarity aims to foster meaningful knowledge co-production through integrative and participatory processes that bring together diverse actors, disciplines, and knowledge bases. In practice, transdisciplinarity is more ambiguous. While there is a growing body of literature on such approaches, there remains no widely-accepted definition, concrete framework, or empirical strategy for how to carry out a transdisciplinary project. We propose that this lack of explicit structure and entrenched meaning leaves space for transdisciplinary approaches to be shaped by the evolving network of participating scientists and stakeholders, according to their perspectives of the approach and what it embodies. Here, we examine the perspectives of a diverse group of actors (n = 42) embarking on a 10-year transdisciplinary research project focused on building resilience to natural hazards and disasters in New Zealand. We present the findings of qualitative surveys and group interviews that investigate stakeholders’ and scientists’ early perspectives of transdisciplinary, or co-created, research. The study represents the first stage of longitudinal research that will continue over the course of the project. Results show that early actors in the project share an overall consistent understanding of co-created research. Participants described a process that integrated diverse people and knowledge; created benefits on both a social and personal level; fostered clear, two-way dialogue; and overcame pragmatic and intrinsic challenges. Collectively, participants agreed with adopting transdisciplinary approaches to natural hazard, risk, and resilience research, with stakeholders showing a stronger degree of agreement than scientists. While attitudes towards transdisciplinarity were overall positive, a number of underlying conflicts emerged in regards to carrying out new modes of knowledge production within traditional social and institutional structures. These conflicts result in a tension that is felt by actors involved in transdisciplinary projects early on, and in some cases, influences perception of their ability to fully participate in such an approach. Evaluating actor perspectives and expectations early in the transdisciplinary process can give insight into how attitudes, expectations, and conflicts might shape transdisciplinary efforts, and can provide relevant parameters for assessing change over time.     

系统决策与作物布局——徐州地区秋作物布局实例分析

作物布局是农业生产的一个重要环节,直接关系到农业生态系统资源输入(物质条件、科学技术、气候资源和生物资源等)的利用和转化效率的高低。因为系统输入的资源是非定常的,尤其是天气气候条件年际之间是不同的,本文在年型预测的基础上,确定在不同天气气候条件下的作物合理布局。     

Predicting ectotherm disease vector spread—benefits from multidisciplinary approaches and directions forward

The occurrence of ectotherm disease vectors outside of their previous distribution area and the emergence of vector-borne diseases can be increasingly observed at a global scale and are accompanied by a growing number of studies which investigate the vast range of determining factors and their causal links. Consequently, a broad span of scientific disciplines is involved in tackling these complex phenomena. First, we evaluate the citation behaviour of relevant scientific literature in order to clarify the question “do scientists consider results of other disciplines to extend their expertise?” We then highlight emerging tools and concepts useful for risk assessment. Correlative models (regression-based, machine-learning and profile techniques), mechanistic models (basic reproduction number R ₀) and methods of spatial regression, interaction and interpolation are described. We discuss further steps towards multidisciplinary approaches regarding new tools and emerging concepts to combine existing approaches such as Bayesian geostatistical modelling, mechanistic models which avoid the need for parameter fitting, joined correlative and mechanistic models, multi-criteria decision analysis and geographic profiling. We take the quality of both occurrence data for vector, host and disease cases, and data of the predictor variables into consideration as both determine the accuracy of risk area identification. Finally, we underline the importance of multidisciplinary research approaches. Even if the establishment of communication networks between scientific disciplines and the share of specific methods is time consuming, it promises new insights for the surveillance and control of vector-borne diseases worldwide.     

浏阳农业结构类型及可持续发展的技术对策

根据农业自然资源特点、经济发展水平和生态环境状况,建立了区域农业结构类型的划分方法,把区域农业结构划分为8种类型。运用这一划分方法,对浏阳市农业资源、经济与生态结构类型进行了划分,结果表明,浏阳属于农业自然资源相对短缺、经济相对发达和生态环境状况相对较差的农业结构类型。在此基础上,用定位分析方法分析了浏阳市区位、资源位、经济位和生态位特点,对15种农业生态系统模式的效益状况进行了对比分析。根据农业发展现状,针对资源利用、产业发展及生态环境方面存在的问题,提出了实现农业可持续发展的技术选择:劳动密集型技术、品种资源改良与优良农业生物资源的引进、农产品加工及深加工技术、无公害、绿色和有机食品开发利用技术、旅游资源开发利用技术及废弃物资源化利用技术。     

Nonparasitic Nematoda provide evidence for a linear response of functionally important soil biota to increasing livestock density

Soil acidity, nutrient availability and livestock density have a major influence on the belowground ecological community. As fast decomposition rates are due mostly to bacterial-based pathways and slower decomposition rates mostly to fungal-based pathways, it is helpful to condense empirical information in the so-called Nematode Channel Ratio (NCR). The NCR is shown to be a good indicator of efficiency in soil decomposition processes. We argue that in intensive agroecosystems, other fungivore members of the decomposer food web may outcompete the hyphal-feeding nematodes. We demonstrate how the NCR can be used to set ecological standards for sustainable use of the soil in agroecosystems. To summarize the interactions between the microbial resources and the decomposer nematofauna according to increasing land management, we propose the use of the fifth percentile as proxy for a sustainable environmental quality of grasslands on sandy soils, and the NCR mean as the upper threshold for low-stocked farms.     

Interdisciplinary production of knowledge with participation of stakeholders: A case study of a collaborative project on climate variability,human decisions and agricultural ecosystems in the Argentine Pampas

There is a growing perception that science is not responding adequately to the global challenges of the 21st century. Addressing complicated, “wicked” current and future environmental issues requires insights and methods from many disciplines. Furthermore, to reach social robustness in a context of uncertainty and multiple values and objectives, participation of relevant social actors is required. As a consequence, interdisciplinary research teams with stakeholder or practitioner involvement are becoming an emerging pattern for the organization of integrative scientific research or integrated assessments. Nevertheless, still there is need to learn from actual experiences that bring together decision makers and scholars from different disciplines. This paper draws lessons from a self-reflective study of the collaborative process in two interdisciplinary, multi-institutional, multinational research teams addressing linkages between climate variability, human decisions and agricultural ecosystems in the Argentine Pampas. During project design, attention must be placed on team composition, ensuring not only that the needed talents are included, but also recruiting investigators with an open attitude toward interdisciplinary interaction. As the project begins, considerable effort must be dedicated to shared problem definition and development of a common language. Simple conceptual models and considerable redundancy in communication are helpful. As a project evolves, diverging institutional incentives, tensions between academic publication and outreach or policy-relevant outputs, disciplinary biases, and personality issues play increasingly important roles. Finally, toward a project's end the challenge arises of assessing interdisciplinary, integrative work. The lack of consensus on criteria for assessment of results is often ranked as a major practical difficulty of this kind of research. Despite many efforts to describe and characterize collaborative research on complex problems, conditions for success (including the very definition of “success”) remain to be rigorously grounded on actual cases. Toward this goal, we argue that a self-reflective process to identify and intervene on factors that foster or impede cooperative production of knowledge should be an essential component of integrated assessments involving scientists, practitioners and stakeholders.     

Farmers’ perceptions of climate variability and barriers to adaptation: lessons learned from an exploratory study in Vietnam

Southeast Asian countries are confronting climate variability, challenging agricultural sustainability and rural livelihoods. However, little research effort has been devoted to exploring how farmers in those countries perceive climate variability and how the perceptions link to adaptive responses. This paper deploys information from three focus group discussions with 30 male farmers; and six in-depth interviews with one female and five male agricultural officers in the Mekong Delta, Vietnam. Recorded 34-year meteorological data in the delta from 1978 to 2011 is also incorporated to demonstrate the actual climate variability of the region. We find that farmers are becoming increasingly conscious of local climate variability issues. However, they have limited understanding of the importance of adaptation to their livelihoods. They also have limited knowledge of where and who to contact for appropriate climate change adaptation information. No opinions about the link between global warming and local climate variability and change were observed. Casual observation via public media and personal experience dominated farmers’ sources of information. Barriers to farmers’ adaptation are not exclusively restricted to socio-economic factors and resource constraints; e.g. land tenure, technical knowledge, market, social relationship, credit, information, health care, and demographics. Maladaptation, habit, and the perception of the importance of climate variability and adaptation are found as additional constraints. Observed differences in farmers’ and agricultural officers’ perspectives regarding barriers to farmers’ adaptation suggest important policy implications.     

农业生态系统中杂草资源的可持续利用

杂草是农业生态系统中对农作物的生长和产量产生重要影响的伴生植物。杂草具有耐不良环境、生长快、繁殖力强等优良特性,是重要的生物资源。可利用杂草的优良基因作为农作物遗传改良的基因供体,利用其有用成分开发中医药,利用植物他感效应进行害虫生物防治,可开发成观赏植物,可作为先锋物种进行生态恢复、改良环境、促进养分循环、保护土壤微生物等。杂草的化学防除是导致杂草资源丧失的重要因素,寻找既利于杂草资源保护又不影响农作物生长的防除途径、杂草资源数据库的创建、杂草资源有益基因的发掘和开发利用,是杂草科学今后应加强的研究方向。     

Modifying traditional and high-input agroecosystems for optimization of microbial symbioses: a case study of dry beans in Costa Rica

Optimization of symbioses between plants and microbes has been suggested as method for enhancing nutrient uptake in low-input agroecosystems. In generall symbioses may be maximized through: (1) the selection of plant cultivars responsive to symbiontss; (2) ionoculation with highly efficient strains of symbionts; (3) habitat modification to encourage symbioses. These methods were tested under a traditional, slash mulch, ‘frijol tapado’ en agroecosystem and/or a high-input (‘espequeado’) system to increase nodulation and vesicular-arbuscular mycorrbizae (VAM) of beans with the following results: (1) Under the espequeado system (modified by the exclusion of fertilizer application), four cultivars of indeterminate, vining dry beans (Phaseolus vulgaris) nodulated more than two determinate, bush varieties, especially under low available soil phosphorus (P). VAM levels were not statistically different under these conditions. (2) Under the tapado system, pelletization with rock phosphate and Rhizobium inoculum did not significantly change nodule biomass, dinitrogen (N₂)-fixation or yield. (3) Without P application, neither nodulation nor % VAM were significantly different between the two systems of bean production. However, as applied P increased, differences in %VAM of the two systems became significant, decreasing more sharply with increasing P in the tapado system.The tripartite symbiosis of beans can be influenced by various factors such as cultivar, nutrient application and production system. Although traditional varieties and systems may optimize certain microbial symbioses, the quantity of the symbiosis appears to depend on a number of complex factors. An intermediate agricultural technology, the mixing of traditional and modern, is exemplified here by the application of moderate levels of fertilizer to the tradional, tapado systems. This intermediate approach promises to decrease inputs in comparison to the espequedo system, as well as the need for shift cultivation, but long-term testing is needed.     

DRASTIC评价模型在台州市浅层地下水脆弱性评价中的应用

本文介绍了DRASTIC评价体系在台州市浅层地下水的脆弱性评价中的应用。根据台州市的地质背景、水文地质条件等,对DRASTIC评价指标进行改进,选择了地下水埋深等4个参数作为研究区地下水脆弱性评价因子,建立了台州市浅层地下水脆弱性评价模型。结合G IS技术对该地区的地下水脆弱性进行了评价,编制了地下水脆弱性评价图。综合评价的结果表明改进的DScTI评价模型能合理的反映台州市浅层地下水环境脆弱性的高低。     

环境正义研究前沿及其启示

环境正义不仅是重大的现实问题,也是不同学科和领域研究的焦点。通过对国内环境正义研究文献的梳理,比较分析环境正义所涉学科、内容和方法后发现：环境正义研究呈现出多学科视角、多元化主题和学科交叉趋势,但研究体系不够完善,缺乏理论创新;亟待构建中国特色环境正义理论体系和分析框架,总结中国环境正义研究案例和解决模式;环境正义概念多而不统一,混杂而不明确,需进一步厘清和辨明;考虑多维内涵、多重维度和多维原则,建构和完善环境正义概念体系;环境正义问题主要表现在多尺度区域和多类型群体两个层面,环境强势群体（区域）与弱势群体（区域）的环境权责不对等是焦点;城乡环境正义问题广受关注,需加强经济弱势地区和环境弱势地区环境正义研究;解决环境正义问题的政策措施缺乏系统性考量和可操作性,在具体的社会文化和地方情境中探讨环境正义及其解决之道是重点;按照问题的轻重缓急,分区域分群体逐步消除环境不正义;环境正义评价标准欠缺,不同学科数据和方法交叉融合不足。未来环境正义研究的重点和难点在于：建构一个问题导向的、跨学科交叉的环境正义理论框架;精确表征和测度环境（不）正义;模拟多尺度、多主体的环境正义演变过程;基于地方性加强环境正义的典型案例研究。