Assessing the Potential Effects of Fungicides on Nontarget Gut Fungi (Trichomycetes) and Their Associated Larval Black Fly Hosts

Fungicides are moderately hydrophobic and have been detected in water and sediment, particularly in agricultural watersheds, but typically are not included in routine water quality monitoring efforts. This is despite their widespread use and frequent application to combat fungal pathogens. Although the efficacy of these compounds on fungal pathogens is well documented, little is known about their effects on nontarget fungi. This pilot study, a field survey in southwestern Idaho from April to December 2010 on four streams with varying pesticide inputs (two agricultural and two reference sites), was conducted to assess nontarget impact of fungicides on gut fungi, or trichomycetes. Tissues of larval black flies (Diptera: Simuliidae), hosts of gut fungi, were analyzed for pesticide accumulation. Fungicides were detected in hosts from streams within agricultural watersheds but were not detected in hosts from reference streams. Gut fungi from agricultural sites exhibited decreased percent infestation, density and sporulation within the gut, and black fly tissues had elevated pesticide concentrations. Differences observed between the sites demonstrate a potential effect on this symbiotic system. Future research is needed to parse out the details of the complex biotic and abiotic relationships; however, these preliminary results indicate that impacts to nontarget organisms could have far‐reaching consequences within aquatic ecosystems.     

大都市传统工业区休闲旅游转型发展研究综述

传统工业区休闲旅游转型是大都市城市功能和产业空间优化的关键问题,目前该方面研究尚未形成系统性的理论研究体系.论文梳理了国内外相关研究成果,从休闲旅游转型趋势,转型价值,转型空间演化,转型要素,转型模式,转型效应和转型策略等方面进行了研究内容和研究结果的总结,评述了国内外在研究时间,研究内容,研究方法上的差异.最后认为现有研究缺乏从人地关系视角对传统工业区转型背景,要素,动力,空间演化的系统分析,今后应针对中国大都市发展特点,重点关注传统工业区休闲旅游转型发展模式,转型过程,机制以及综合效应等方面的研究,从理论性和可操作性上指导我国城市传统工业区的休闲旅游改造.     

Is aridity restricting deforestation and land uses in the South American Dry Chaco?

In this paper, we explored how aridity influences the regional deforestation and land-use patterns (i.e. crops/pastures) in South American Dry Chaco. To do this, we contrasted land use during last decade (2001–2012) with a spatially explicit aridity index, which we complemented with a crop water balance model. Land-use classifications were performed by considering the temporal variability of NDVI from MODIS satellites, showing that 40 and 60% of deforested land was assigned to crops and pastures, respectively. Results indicate that although the regional deforestation pattern was not associated with the aridity gradient, with drier areas similarly deforested as wetter areas, contrasting differences were observed in the use of this land, with crops mostly located (90%) in wetter areas and pastures evenly distributed across the whole aridity gradient. This research highlighted the strong effect of water limitations on the land-use option after deforestation and may help to set the basis for future land-use planning policies.     

Moving towards sustainable development: rhetoric,policy and reality of ecological agriculture in China

Past decades have witnessed the rise of sustainable agriculture movements throughout the world. In parallel with this international trend, ecological agriculture (with essential goals of food security, rural employment, poverty alleviation, natural resource management and environmental protection) has been advocated as a workable approach for the realization of sustainable agriculture in China. Two decades of ecological agricultural development have shown that it not only gained legitimacy at the senior policy level but also became a focus of scientific research in fields such as ecological economics, ecology, and agricultural and environmental sciences. However, this endeavour is hardly known in the West and little attention has been paid so far to examining the broader politico-economic and sociocultural contexts within which it has evolved. This paper attempts to provide a general review of the emerging background, development history, policy initiatives and recent tendencies of ecological agriculture. In addition, the extant problems and potential contributions of this alternative practice to China's sustainable agricultural development are discussed. The purpose of this study is to identify the gap between the policy rhetoric and practical implementation of Chinese ecological agriculture and therefore to facilitate its moving towards sustainable development.     

国际标准产业分类体系的农、林、牧、渔业分类演化及启示

国际标准产业分类体系是目前国际上最有影响和权威的产业分类体系。深入了解国际标准产业分类体系中农、林、牧、渔业分类演化,对正确收集、处理和测算我国农、林、牧、渔业的指标以及国际间数据比较至关重要。论文首先详细地剖析国际标准产业分类体系的农、林、牧、渔业的分类演化,然后依据国际标准产业分类体系的最新变化,结合我国农、林、牧、渔业现状,为我国国民经济行业分类中农、林、牧、渔业的修改和调整提供建议。     

Interrelation of Cd‐lon concentrations and the growth and activities of microorganisms in two growth media†

Partitioning of native or anthropogenic heavy metals in solid and solution phases of soil is a result of network of several physico‐chemical reactions. The attainment of equilibrium between two phases is also regulated by biochemical processes. For practical purposes, the bioavailability of metal present in soil is predominantly regulated by the soil solution phase which is in dynamic equilibrium with the solid phase. The results of a model laboratory and greenhouse growth experiments have been used to investigate the effect of Cd‐ion concentrations (either in soil solution or in nutrient solution) on the growth and activities of microorganisms. The soil solution has been simulated by preparing a suspension of soil with 0.1 M NaNO₃ (1: 2.5) equilibrated for two hours. Important conclusions are as follows:

Increase in Cd‐ion concentration in soil solution or in nutrient solution induces corresponding adverse effect on the growth and activities of microorganisms. Thus, it seems that Cd‐ion concentration is a more sensitive indicator for assessing the effect of metal pollution upon the growth and activities of soil microorganisms in comparison to total Cd contents.

During active microbial growth phase, a large part of the organically bound Cd was released in the soil solution which is largely bioavailable. This process is termed as mobilisation. There was momentary increase of Cd‐ion concentration in soil solution which intoxicated the growing organisms. After this stage, the Cd ions from the solution phase were removed by the newly formed solid phase (nonviable biomass) and were transformed in non‐available form. This process is termed as immobilisation.

The consequences and importance of these results for practical agriculture and in deciding the limits or guidelines on the maximum tolerable metal load in soils are discussed.     

Multicriteria analysis applied to the sustainable agriculture problem

SUMMARY

The aim of this paper is to present an operational approach to compare the relative sustainability of existing farming systems. Sustainability rests on the assumption that an equilibrium must exist among three domains: social, economic and ecological. If we are to look for a solution to the problem, we must face a multi-dimensional approach. We propose that multicriteria analysis, a multi-dimensional method, is an appropriate methodology to study the issue. As sustainability cannot be measured directly, the way out is to use indicators. We have performed a thorough analysis of four farming systems existing in Guaíra, SP, Brazil to validate the methodology. Thirty indicators of sustainability (ten ecological, ten social, and ten economic) were defined and used to perform the analysis. The results of the multicriteria analysis proved useful because of its capability of reducing the dimensionality of the problem. From the three dimensions of sustainability, a final score was derived that can easily compare the relative sustainability of each farming system.     

Application of analytical hierarchy process and geographic information systems in land-use suitability evaluation: a case study of Dümrek village (Çanakkale,Turkey)

This study used both analytical hierarchy process (AHP) and geographic information systems (GIS) to make a land-use suitability analysis for the village of Dümrek, NW Turkey. Primarily, alternative land uses for agriculture, meadow–pasture and forest were determined along with criteria for these alternatives and a hierarchical structure was produced and used to determine the weights of the criteria. Spatial data were identified by means of GIS and calculations were made using the suitability values specified and weights obtained from AHP. Suitability maps were then produced for the above land use alternatives. Subsequently, a synthesized suitability map was formed from these maps. According to the weights specified by AHP, the order of land use preferences among the alternatives for rural development of Dümrek was agriculture, forest and meadow. The synthesized suitability map showed that the areas allocated for forest and agriculture were close to the present ratios of use; however, meadow land, which does not exist at present, should be allocated as a land use to constitute 12.5% of the study area. Achieving sustainability in land use is possible by planners and administrators considering results obtained from land suitability mapping studies at the stage of allocating land uses. The method applied in this research is considered useful when taking policy decisions covering the evaluation of rural land use, particularly for subunits of the state administration.     

Biofuels and agriculture: a past perspective and uncertain future

The US corn ethanol industry has grown from virtually nothing in the early 1980s to over 14 billion gallons in 2011. Subsidies have been an important impetus for the industry, and they have existed in one form or another throughout the life of the industry. This paper provides (1) a brief look at the history of the linkages between energy and agriculture and how they have changed with biofuels; (2) a review of some of the major impacts of the US corn ethanol program; and (3) analysis of prospective impacts of cellulosic biofuels. There is no doubt that biofuels have brought about a new era for global agriculture. Historically, the prices of agricultural and energy products moved in response to supply and demand factors relevant to each market, but moved largely independent of one another. Corn ethanol has changed that, and today there is a link between crude oil and corn that is driven by the demand side. Since agricultural commodity prices are linked both on the demand and supply sides, the corn–crude oil link spills over to other agricultural commodities as well. Development of cellulosic biofuels has been much slower than hoped. The feedstocks are more expensive than initially believed. Conversion technologies remain uncertain and expensive. There are many uncertainties through the cellulosic supply chain, and government policy remains uncertain as well. Thus, the future of the cellulosic biofuels industry is, at this point, an open question.     

Sustainability aspects of vegetable production in the peri-urban environment of Bogotá, Colombia

Although the peri-urban region around Bogotá, Colombia contains a diversified horticulture sector, local vegetable production suffers from a critical lack of research and availability of un-biased, scientifically validated information on crop management. In this study, we identify current trends and deficiencies in fertilisation and pest management for local vegetable production. We relate pesticide type with target pests, evaluate temporal patterns in pesticide and fertiliser use for a key crop (i.e. spinach) and conduct basic nutrient budget accounting. Personal interviews with vegetable growers were combined with a detailed follow-up of management activities and soil nutrient profiles on pilot farms in two different peri-urban municipalities. Most (84%) vegetable growers relied on personal experience, and indicated a lack of unbiased information on fertiliser effectiveness and pesticide action spectra. The majority of farmers used pesticide mixtures on a calendar basis and commonly applied products below recommended doses. Soil nutrient accounts indicate insufficient fertilisation and a progressive depletion of key nutrients. Extraction rates for the principal vegetable crops exceeded by 33.6%, 20.5% and 93.0% soil nutrient availability of N, P and K, respectively. Organic products are included in local fertilisation schemes, with chicken manure as the principal source, at an average application rate of 6 t ha^?1. Our findings could help policymakers and local institutions set a research and extension agenda to promote sustainable peri-urban vegetable production and help secure peri-urban livelihoods while ensuring healthy and safe horticultural production.