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81.
The year-round dynamics of laccase and acid phosphatase activities of ectomycorrhizas (EM) were monitored in an oak forest, with a microplate photometric method using individual EM root tips. Among the most frequent and abundant EM morphotypes, those of Lactarius quietus and Cortinarius anomalus showed a peak of laccase activity in spring, while those of Xerocomus chrysenteron displayed highest laccase activities in summer and autumn. In comparison, less seasonal differences were observed in EM acid phosphatase activity. This suggests that the different EM types within the EM community perform complementary functions depending on season. 相似文献
82.
Jon E. Schoonover Karl W. J. Williard James J. Zaczek Jean C. Mangun Andrew D. Carver 《Water, air, and soil pollution》2006,169(1-4):303-315
The sediment filtering capabilities of giant cane (Arundinaria gigantea (Walt.) Chapm.) and forest riparian buffers were compared in a southern Illinois, USA non tile drained agricultural watershed. Giant cane, a bamboo species, serves as important wildlife habitat throughout its native range in the southeastern and lower midwestern United States. Overland flow samples were collected at the field edge and at 3.3 m, 6.6 m, and 10.0 m within the riparian buffers during 19 precipitation events over a 1-year period. On an annual basis, significant sediment reductions occurred by 3.3 m and 6.6 m in the cane and forest buffers, respectively. The giant cane buffer reduced incoming sediment mass by 94% within the first 3.3 m, while the forest buffer reduced sediment by 86% over 6.6 m. Within 10.0 m of the field edge, the cane and forest buffers reduced sediment mass by 100% and 76%, respectively. On a seasonal basis, the cane buffer outperformed the forest buffer. During each of the four seasons, the cane buffer reduced sediment masses within 3.3 m of the field edge, while the forest buffer showed initial reductions occurring at 6.6 m during the summer, fall, and winter. No detectable reductions occurred during the spring in the forested buffer. Reductions in sediment concentrations were less evident compared to mass basis, indicating that infiltration may be a more important sediment reduction mechanism than particle settling. Both the forest and giant cane buffers had relatively high measured soil infiltration rates. Study results indicate that giant cane is an appropriate species to include in riparian buffer restoration designs for sediment control. 相似文献
83.
Peter?Schr?derEmail author Beate?Huber Jean?Charles?Munch 《Journal of Soils and Sediments》2003,3(4):223-226
All forms of agriculture cause changes in the balances and fluxes of preexisting ecosystems, thereby limiting self-regulatory
ecosystem (resiliency) functions. The intensive agriculture of the past, with its strong reduction of landscape structures
and vast decoupling of energy and matter cycles, has caused stress and degradation of the production base; massive influence
has also been exerted on neighboring compartments. This has resulted in the well known problems of pesticide loads, high phosphate
loads to surface waters via over-fertilized soils or erosion as such. To overcome the economic, social and political inadequacies
leading to ecological degradation, the demand for sustainable agricultural management needs to be transposed into knowledge-based
practical instructions and political regulations on a regional scale. Thus, applied research for a sustainable and ecologically
compatible land use aimed at sufficient food production is ever so important. In the FAM, thirty German research institutes
have merged to perform research on this topic. 相似文献
84.
Marx J 《Science (New York, N.Y.)》2004,306(5701):1455-1457
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Marx J 《Science (New York, N.Y.)》2008,320(5872):38-41
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