崆峒山七叶一枝花与北重楼的分布格局及光合适应性差异研究OA

To clarify the resource distribution patterns and photosynthetic physiological-ecological adaptation mechanisms of Paris polyphylla var.chinensis and P.verticillata in Kongtong Mountain,and to provide a scientific basis for the protection,sustainable development and utilization of their wild resources,this study employed the line-transect and quadrat method to investigate the community structure and distribution characteristics of the two plant species,and used portable photosynthesis and chlorophyll fluorescence instruments to measure their key photosynthetic physiological indicators.The results showed that although the humid microhabitat under the forest in Kongtong Mountain could meet the basic growth requirements of both species,the intense plant competition within the community led to a low distribution density of their wild populations.In terms of photosynthetic characteristics,the core indicators such as net photosynthetic rate(Pn)and transpiration rate(Tr)of P.verticillata were significantly higher than those of Paris polyphylla var.chinensis(p<0.05).Correlation analysis revealed that the Pn of both plant species was highly significantly negatively correlated with intercellular CO2 concentration(CO2int)(p<0.01)and highly significantly positively correlated with leaf water use efficiency(LUE)(p<0.01).The Tr of both species was significantly positively correlated with leaf temperature(Tleaf)(p<0.05),and the correlations between Tr of P.verticillata and leaf intercellular CO2 concentration(Cleaf)as well as air temperature(Ta)reached a highly significant level(p<0.01).Comprehensive analysis indicated that Paris polyphylla var.chinensis and P.verticillata were mainly concentrated in the shaded slope areas under the forest in Kongtong Mountain.P.verticillata could better adapt to the high-light and low-humidity habitats through a midday photosynthetic depression strategy.However,the ecological environment characteristics(insuffi-cient canopy density and low humidity)and community structure of the shaded slope areas in Kongtong Mountain imposed restrictions on the distribution of both plant species,of which Paris polyphylla var.chinensis exhibited weaker habitat adapta-bility.This study indicates that during the conservation and development of the two medicinal plant species,emphasis should be placed on the maintenance and improvement of their habitat conditions,and targeted protection of the wild populations of Paris polyphylla var.chinensis should be particularly strengthened.