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分析杨树速生丰产林营造林辅助决策系统
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作者 李春福 《才智》 2012年第22期29-29,共1页
林业信息化是林业发展的必由之路,通过分析立地质量评价方面的理论和方法,做到速生丰产林,营林管理信息化、决策智能化,完成杨树速生丰产林造林设计方案,能够为营造林提供准确、有效的辅助信息。
关键词 树速生丰产林 辅助决策系统
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Microbial Community Changes Along a Land-Use Gradient of Desert Soil Origin 被引量:10
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作者 WANG Bao-Zhan ZHANG Cai-Xia +7 位作者 LIU Ji-Liang ZENG Xiao-Wei LI Feng-Rui WU Yu-Cheng LIN Xian-Gui XIONG Zheng-Qin XU Jian JIA Zhong-Jun 《Pedosphere》 SCIE CAS CSCD 2012年第5期593-603,共11页
Soil harbors remarkably stabilize bacterial communities at the phylum level. However, no two soils have exactly the same structure of bacterial phyla. The structure of microbial community is strongly influenced by the... Soil harbors remarkably stabilize bacterial communities at the phylum level. However, no two soils have exactly the same structure of bacterial phyla. The structure of microbial community is strongly influenced by the type of land-use through changes in soil attributes. Using high-throughput pyrosequencing and quantitative polymerase chain reaction techniques, soil microbial community structures were investigated along a land-use gradient of 100- and 27-year farmlands, a 33-year Pinus forest, a 28-year poplar forest, and a 21-year shrubland, as well as a native desert from which all cultivated systems were converted. The results revealed that the dominant phylotypes in the native soil comprised primarily of Alphaproteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes, accounting for 〉 71.4% of the total bacterial 16S rRNA sequence reads. Changes in land-use led to a significant decrease in these dominant phylotypes down to 33.4%. In contrast, the phylotypes with low abundance, such as Acidobaeteria, Chloroflexi, Nitrospira, and Gammaproteobaeteria, increased sharply from 4.5%-5.9% in the native soil to 20.9% 30.2% of the total 16S rRNA gene sequences in the cultivated soils except for the soil from the shrubland. These contrasting changes in the major taxa appear to be correlated with the changes in soil attributes. For instance, bacterial and archaeal amoA genes were found to be 960- and 3 800-fold more abundant in the soil from the 100-year farmland than the native soil. The changes in numerically less dominant nitrifying phylotypes are consistent with soil inorganic nitrogen dynamics. Quantification of the 16S rRNA genes demonstrated that bacteria and archaea were about two to three orders of magnitude more abundant in the cultivated soil than in the native soil. Hence, land-use type affects the soil bacterial community structure, which has profound consequences on ecosystem function. 展开更多
关键词 AMOA ecosystem functions land-use type polymerase chain reaction PYROSEQUENCING
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