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国内外速生丰产林的研究动态 被引量:9
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作者 向成华 李晓清 赵毅 《四川农业大学学报》 CSCD 1998年第4期473-479,共7页
根据文献综合论述了速丰生产林的概念、历史发展、建设概况、研究现状,并通过分析讨论了速生丰产林研究的发展趋势。
关键词 生丰产林 发展趋势 产现状 用材林
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浅谈桉树速生丰产林营造林技术
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作者 张平 《临沧科技》 2012年第3期37-38,共2页
从苗木选择、立地条件、整地挖穴、造林密度、苗木保湿、栽植、抚育管理、病虫害防治等方面介绍了桉树速生丰产林营造技术,以期变粗放式生产为集约经营方式,把桉树发展的重点从扩大面积转到提高单产和质量上来,进一步提高桉树的经济... 从苗木选择、立地条件、整地挖穴、造林密度、苗木保湿、栽植、抚育管理、病虫害防治等方面介绍了桉树速生丰产林营造技术,以期变粗放式生产为集约经营方式,把桉树发展的重点从扩大面积转到提高单产和质量上来,进一步提高桉树的经济效益。 展开更多
关键词 桉树速 生丰产林 营造技术
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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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