4种木本植物在石漠化地区的生长状况及光合特性

以山桐子、桑树、无患子和皂荚为研究对象,比较几种木本植物在石漠化环境条件下的生长状况及光合特性。结果表明:桑树的成活率、株高增长率、地径增长率、根冠比、根干质量等生长指标最好,其次是山桐子和无患子,皂荚最差;桑树和山桐子的光合生产能力较强,无患子和皂荚相对较弱,但无患子的水分利用效率最高,其次是桑树、皂荚,山桐子最低。拟合各类植物Pn-PAR光响应曲线得出:桑树、山桐子和皂荚的最大净光合速率均在15 μmol/(m2·s)左右,高出无患子50%;各树种的表观量子效率大小顺序为:桑树皂荚无患子山桐子,暗呼吸速率为:桑树无患子皂荚山桐子,光补偿点为:无患子皂荚山桐子桑树,光饱和点为:山桐子桑树皂角无患子。可见,从生长状况和光合特性来看,4种木本植物在石漠化环境条件下的适应性为:桑树无患子山桐子皂荚。 

Growth and photosynthetic characteristics of four woody plants in the rocky and desertified area

We studied the growth status and photosynthetic characteristics of four kinds of woody plants, Idesia polycarpa, Morus alba, Sapindus mukurossi and Gleditsia sinensis, that were planted in the rocky and desertified area. 1) According to the growth indexes, such as survival rate, plant height growth rate, base diameter growth rate, dry root weight and root/shoot ratio, the growth status of M. alba was the best, followed by I. polycarpa and S. mukurossi, and G. sinensis in the last place. 2) The photosynthetic capabilities of M. alba and I. polycarpa were stronger that those of S. mukurossi and G. sinensis. As for the water use efficiency, S. mukurossi was the highest, followed by M. alba and G. sinensis, and, in the last place, I. polycarpa. 3 ) I. polycarpa, M. alba and G. sinensis showed the similar maximum net photosynthetic rate, about 15 μmol/(m2·s), which was 50% higher than that of S. mukurossi. The order of apparent quantum yield of the four plants, arranged from high to low, was M. alba, G. sinensis, S. mukurossi and I. polycarpa. The order of dark respiration rate, from high to low, was M. alba, S. mukurossi, G. sinensis and I. polycarpa. The light compensation point followed an order from high to low as S. mukurossi, G. sinensis I. polycarpa and M. alba, while the order of light saturation point was I. polycarpa, M. alba, G. sinensis and S. mukurossi. By comparing the growth status and photosynthetic characteristics of the four plants in the rocky and desertified area, we conclude that their adaptability to the environment follows the order from strong to weak as M. alba, S. mukurossi, I. polycarpa and G. sinensis.