论文部分内容阅读
In order to offer scientific base for the cultivation of Parthenocissus quinquefolia planch in barren mountainous areas, the paper studied the light response characteristics of the photosynthetic rate (Pn) , transpiration rate (Tr) and water use efficiency (WUE) that two-year-old P. quinquefolia planch leaf has under different soil moisture conditions with CIRAS-2 portable photosynthesis system made in PPS corporation in England. The results indicated that the Pn, Tr and WUE of P. quinquefolia planch leaf had notable threshold of responses to the variation of soil moisture and photosynthetic active radiation (PAR). The Pn of P. quinquefolia planch was at a relatively high level when the volumetric water content (VWC) was 12.6%-20.7% and relative water content (RWC) 45.2%-74.3%. When VWC was about 18.3%, the Pn and Tr reached the highest value while the WUE was relatively low. When the VWC was about 12.6% (RWC was about 45.2%), the WUE reached the highest level. The fitting soil moisture range which could keep Pn and WUE at relatively high level was 12.6%-18.3% for VWC and 45.2%-65.7% for RWC. Out of this range, Pn and WUE would descend obviously. In the fitting range of VWC, the Pn and WUE maintained a high level when the PAR range was 400-1000 ? mol.m-2.s-1, otherwise, the WUE would fall, and the most suitable PAR was 800 ? mol.m-2.s-1. In view of the above results, we conclude that the P. quinquefolia planch can adapt to a wide range of illumination intensity. It has the property of strong drought-resistance but can not stand the high soil moisture environment. Therefore, it is a suitable vine for the afforestation in barren mountainous areas.
In order to offer scientific base for the cultivation of Parthenocissus quinquefolia planch in barren mountainous areas, the paper studied the light response characteristics of the photosynthetic rate (Pn), transpiration rate (Tr) and water use efficiency (WUE) that two-year- old P. quinquefolia planch leaf has under soil moisture conditions with CIRAS-2 portable photosynthesis system made in PPS corporation in England. The results indicated that the Pn, Tr and WUE of P. quinquefolia planch leaf had notable threshold of responses to the variation The Pn of P. quinquefolia planch was at a relatively high level when the volumetric water content (VWC) was 12.6% -20.7% and relative water content (RWC) 45.2% -74.3% When VWC was about 18.3%, the Pn and Tr reached the highest value while the WUE was relatively low. When the VWC was about 12.6% (RWC was about 45.2%), the WUE reached the highest level. The fitting soil moisturizer Out of this range, Pn and WUE would descend obviously. In the fitting range of VWC, the Pn and WUE at a relatively high level was 12.6% -18.3% for VWC and 45.2% -65.7% for RWC. and WUE maintained a high level when the PAR range was 400-1000? mol.m-2.s-1, otherwise, the WUE would fall, and the most suitable PAR was 800? mol.m-2.s-1. In view of the above results, we conclude that the P. quinquefolia planch can adapt to a wide range of illumination intensity. It has the property of strong drought-resistance but can not stand the high soil moisture environment. Therefore, it is a suitable vine for the afforestation in barren mountainous areas.