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D'Alessandro M.,University of Neuchatel | Erb M.,University of Neuchatel | Erb M.,Max Planck Institute for Chemical Ecology | Ton J.,University of Sheffield | And 5 more authors.
Plant, Cell and Environment | Year: 2014

Volatile organic compounds (VOCs) released by soil microorganisms influence plant growth and pathogen resistance. Yet, very little is known about their influence on herbivores and higher trophic levels. We studied the origin and role of a major bacterial VOC, 2,3-butanediol (2,3-BD), on plant growth, pathogen and herbivore resistance, and the attraction of natural enemies in maize. One of the major contributors to 2,3-BD in the headspace of soil-grown maize seedlings was identified as Enterobacter aerogenes, an endophytic bacterium that colonizes the plants. The production of 2,3-BD by E.aerogenes rendered maize plants more resistant against the Northern corn leaf blight fungus Setosphaeria turcica. On the contrary, E.aerogenes-inoculated plants were less resistant against the caterpillar Spodoptera littoralis. The effect of 2,3-BD on the attraction of the parasitoid Cotesia marginiventris was more variable: 2,3-BD application to the headspace of the plants had no effect on the parasitoids, but application to the soil increased parasitoid attraction. Furthermore, inoculation of seeds with E.aerogenes decreased plant attractiveness, whereas inoculation of soil with a total extract of soil microbes increased parasitoid attraction, suggesting that the effect of 2,3-BD on the parasitoid is indirect and depends on the composition of the microbial community. © 2013 John Wiley & Sons Ltd. Source


Wielstra B.,Netherlands Center for Biodiversity Naturalis | Boorsma T.,Van Hall Larenstein University of Applied Sciences | Pieterse S.M.,Netherlands Center for Biodiversity Naturalis | De Iongh H.H.,Institute of Environmental science
Forktail | Year: 2011

Finding suitable indicators to monitor the state of disturbance of tropical forests is a challenge. Avian feeding guilds are a promising candidate and we test their practical usefulness. We use checklists compiled during short surveys. The observed species are classified into avian feeding guilds based on a combination of diet and foraging layer. We compare avian feeding guild structure of two forests exploited on a small scale (traditional community forest or hutan adat) with an undisturbed control area. Fieldwork was conducted in duplicate (in two rounds, by different observers) in East Kalimantan (Indonesian Borneo). Four avian feeding guilds were found to show differences in species numbers between the disturbed and control sites: terrestrial insectivores and arboreal nectarivores are more numerous, whereas understorey insectivores and arboreal insectivores are less numerous in terms of number of species. Of these four, understorey insectivores were considered to be the most informative, as understorey species are surveyed most effectively and as the guild contains a relatively large number of species. Standardised monitoring of avian feeding guilds yields valuable information on the state of disturbance of forests, and species checklists based on short surveys are a suitable method to obtain the required data. We recommend including avian feeding guilds in standardised monitoring programmes and discuss possible improvements for a study in a larger framework. © 2011 Oriental Bird Club. Source


Xie F.,Jinan University | Gu J.-G.,Jinan University | Lin Z.-W.,Institute of Environmental science
Chinese Journal of Applied Ecology | Year: 2014

A new assessment method based on principal component analysis(PCA) and entropy weight for ecosystem health was applied to Wanning Reservoir, Hainan Island, China to investigate whether the new method could solve the overlap in weighting which existed in the traditional entropy weight-based method for ecosystem health. The results showed that, the ecosystem health status of Wanning Reservoir showed an improvement trend overall from 2010 to 2012; the means of ecosystem health comprehensive index(EHCI) in each year were 0.534, 0.617, 0.634 for 2010, 2011 and 2012 respectively, and the ecosystem health status was III(medium), II(good), and II(good), respectively. In addition, the ecosystem health status of the reservoir displayed a weak seasonal variation. The variation of EHCI became smaller recently, showing that Wanning Reservoir tended to be relatively stable. Comparison of the weight of indices in the new and the traditional methods indicated that, the cumulative weight of the four indices(i. e., DO, COD, BOD5 and NH4 +-N) had a stronger correlation of 0. 382 for the traditional one than that(0.178) for the new method. It suggested the application of PCA with entropy could avoid the overlap in weighting effectively. In addition, the correlation analysis between the trophic status index and EHCI showed significant negative correlation(P<0.05), indicating that the new method based on PCA with entropy weight could improve not only the assignment of weighting but also the accuracy of the results. The new method here is suitable for evaluating ecosystem health of the reservoir. Source


Qi C.,Hefei University of Technology | Wu F.,Chinese Academy of science | Wu F.,Institute of Environmental science | Deng Q.,Chinese Academy of science | And 5 more authors.
Microchemical Journal | Year: 2011

Antimony (Sb) distribution and accumulation in plants in Xikuangshan Sb deposit area, the only one super-large Sb deposit in the world, Hunan, China were investigated. Results show that soils were severely polluted with the average Sb concentrations up to 5949.20mg kg-1. Sb widely occurred in 34 plants with various concentrations ranging from 3.92mg kg-1 to 143.69mg kg-1, Equisetaceae family has the highest concentration (98.23mg kg-1) while Dryopteridacea family has the lowest one (6.43mg kg-1). H. ramosissima species of Equisetaceae family had the highest Sb average concentration of 98.23mg kg-1 and P. vittata species of Pteridaceae family showed advantage of accumulating Sb from the contaminated environment (Biological Accumulation Coefficient, BAC=0.08). Almost all species enriched Sb in their upground part such as shoot, leaf and flower (Biological Transfer Coefficient, BTC>1), which may attribute to the high acropetal coefficient and Sb transformation from the atmosphere to the plants. P. phaseoloides and D. indicum showed predominantly accumulation of Sb in the upground part with BTC of 6.65 and 5.47, respectively.From the low bioavailable fraction in soils and weak relationship between total soil concentrations in soils and plants, it seems that the Sb bioavailability was limited and varied with different soil sites as well as plant species. Those observations would be significant to the phytoaccumulation and phytoremediation of plants and ecological and environmental risk assessment in Sb contaminated areas. © 2010 Elsevier B.V. Source


Wen Y.,Institute of Environmental science | Chen H.,Institute of Environmental science | Shen C.,Institute of Environmental science | Zhao M.,Zhejiang University | Liu W.,Zhejiang University of Technology
Environmental Science and Technology | Year: 2011

Reactive oxygen species (ROS) are considered to be the key players in cell toxicity. However, cross talk between the enantioselective toxicity of pesticides, heavy metals, and ROS is poorly understood. To decipher the puzzle, the effects of copper (Cu) on the enantioselective ecotoxicity of the chiral pesticide dichlorprop (DCPP) to Scenedesmus obliquus were investigated. The results showed that the presence of DCPP and Cu, both individually and in combination, caused a sudden increase of ROS. This in turn stimulated the response of antioxidant defenses, impaired subcellular structure and physiological function, and finally resulted in cell growth inhibition. In the absence of Cu, ROS production after exposure to the herbicidally active (R)-enantiomer was higher than that of the (S)-enantiomer, suggesting a preference for an (R)-enantiomer-induced production of ROS. When DCPP and Cu were both added to algae simultaneously, (R)-DCPP preferentially induced production of ROS was observed. However, the enantioselective induced production of ROS was reversed when DCPP was mixed with Cu for 24 h prior to addition to the algae solution. It was also found that the generation of ROS, antioxidant response, and growth inhibition rate in Scenedesmus obliquus were all (R)-enantiomer preferentially induced. These findings implied that ROS play a primary role in chemical contaminant toxicity, and interactions between contaminants can tune the enantioselectivity of chiral herbicides, which should be considered in future risk assessment. © 2011 American Chemical Society. Source

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