贵州玉舍国家森林公园三种造林植物光合生理特征研究

Photosynthetic physiology characteristics of three afforestation tree species in Guizhou Yushe National Forest Park

关键词:  喀斯特, 光合作用, 叶绿素荧光, 碳酸酐酶, 稳定碳同位素组成

Key words:  karst, photosynthesis, chlorophyll fluorescence, carbonic anhydrase, stable carbon isotopic composition

摘要:

该研究以贵州省玉舍国家森林公园三种造林植物水榆花楸(Sorbus alnifolia)、近轮叶木姜子(Litsea elongata var. subverticillata)、山杨(Populus davidiana)为对象,测定其光合作用日变化和叶绿素荧光、叶片碳酸酐酶活力以及叶绿素含量和稳定碳同位素组成,并测定了植物生长地土壤理化性质,综合分析了三种植物的喀斯特生态适生能力。结果表明:水榆花楸和山杨的净光合速率明显高于近轮叶木姜子,这与其较高的气孔导度和光化学效率有关; 而山杨因具有较高碳酸酐酶活力和叶绿素含量,表现出较高的水分利用效率。水榆花楸和山杨的光合生产能力较高,且受光强和温度限制,可在光照较好的地区大范围种植,作为速生植物来加快经济收入并改造当地脆弱生境的优选植物; 近轮叶木姜子作为中药型植物,且在低光强下能够保持最大生长能力,可在光照条件不好的地区优先种植,既增加植被覆盖率又增加经济收入。该研究结果为山地森林资源的保护和开发利用提供了科学依据。

Abstract:

Karst is widely distributed in our country, its ecological environment is fragile, and vegetation restoration is an effective way to repair and reconstruct the karst fragile ecological environment, but the key to vegetation restoration is to screen suitable plant that can adapt to karst fragile environmental conditions. To study the photosynthetic physiology and ecology of afforestation plant species in karst area, so as to provide scientific basis for the protection and exploitation of mountain forest resources. In this study, three afforestation plant species, Sorbus alnifolia, Litsea elongata var. subverticillata and Populus davidiana, were collected from Yushu National Forest Park of Guizhou Province. Plant photosynthesis and chlorophyll fluorescence, leaf carbonic anhydrase activity and chlorophyll content and stable carbon isotopic composition, and the soil physical and chemical properties of plant growth location were determined, and the karst ecological adaptability of three plant species was comprehensively analyzed. The results showed that the net photosynthetic rates of Sorbus alnifolia and Populus davidiana were significantly higher than that of Litsea elongata var. subverticillata, which were related to its higher stomatal conductance and photochemical efficiency. Populus davidiana had higher activity of carbonic anhydrase and chlorophyll content, showing a higher water use efficiency. Sorbus alnifolia and Populus davidiana, dominated by the photosynthetic activity, and are limited by light intensity and temperature, as the fast-growing plants can be selected to large-scale grown in good light conditions to increase economic income and improve the fragile habitats in karst areas. However, the photosynthetic rate of Litsea elongata var. subverticillata was lower than that of other two plant species, combined with its highest photosynthetic capacity under low photosynthetic active radiation, this medical plants can be as the shade plant to raise the vegetation coverage and increase local economic income. The results provide a scientific basis for the protection and exploitation of mountain forest resources.