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Photosynthesis adaption in Korean pine to gap size and position within Populus davidiana forests in Xiaoxing’anling, China 被引量:2
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作者 Xuannan Li Yahui Wang +2 位作者 Zhihui Yang Ting Liu Changcheng Mu 《Journal of Forestry Research》 SCIE CAS CSCD 2022年第5期1517-1527,共11页
Forest gaps restrict the restoration of temperate secondary forest to broad-leaved Korean pine forest in zonal climax vegetation by affecting the growth of Korean pine(Pinus koraiensis).However,the photo synthetic ada... Forest gaps restrict the restoration of temperate secondary forest to broad-leaved Korean pine forest in zonal climax vegetation by affecting the growth of Korean pine(Pinus koraiensis).However,the photo synthetic adaptability of Korean pine to gap size and position within the gap is unclear.In order to explore the adaptability of young Korean pine(35 years) to different gap sizes in Xiaoxing’anling,photo synthetic capacity and microenvironmental factors(leaf temperature,light transmittance) of Korean pine needles in three positions in the gap(central,transition,and edge areas) were investigated.Three gaps were identified in the secondary Populus davidiana forest:a large 201 m^(2) gap,a middle 112 m^(2) gap,and a small 50 m^(2) gap;12 m^(2) of the understory was sampled as a control.The results show that:(1) maximum net photosynthetic rate(P_(max)) in needles of Korean pine growing in the large gap was higher than in the small gap,and P_(max) in the centre in the same gap was higher than in the transition and edge areas;(2) light saturation point(LSP) and photosynthetic quantum yield(AQY)of needles in the large gap were higher than in the small gap,while the light compensation point(LCP) and chlorophyll contents of needles were lower in the small gap;and,(3)P_(max) had a significant positive correlation with temperature and light transmittance.It is suggested that the larger the gap in secondary Populus davidiana forests,the greater the change in light intensity and temperatures,the stronger the light adaption of Korean pine needles and the higher the photosynthetic capacity.Therefore,in the recovery of broadleaved/Korean pine forests,suitable gaps should be created and gap microhabitats fully utilized to accelerate the restoration process. 展开更多
关键词 Pinus koraiensis gap size position in the gap Maximum net photosynthetic rate
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PLC和位置控制器在冶金设备控制中的应用
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作者 赵建辉 《冶金矿山设计与建设》 1998年第1期57-59,共3页
介绍了半浮芯棒连轧管机的轧辊辊缝控制系统,采用PLC和位置控制相结合,对轧辊辊缝进行了高精度的定位控制,达到预期效果。
关键词 连轧管机 辊缝控制 位置控制器 冶金设备 PLC
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