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为选择适宜物种来优化和改善岩溶石漠化地区先锋群落的结构,本文采用盆栽控水实验来检验不同水分条件下先锋灌木黄荆条对其树冠下青冈栎和茶条木幼苗的影响。结果表明:不管是处于黄荆条树冠下还是空地上青冈栎和茶条木幼苗的地径、株高相对生长率都随着水分条件的改善而增大;同一水分条件下,树冠下幼苗的相对生长率总低于空地上,且这种差距随水分增加逐渐增大;青冈栎幼苗叶片的相对叶绿素含量(SPAD)在空地上随水分增加无明显变化,树冠下随水分增加而增大;茶条木的SPAD值在空地上随水分增加而增大,树冠下无明显变化;同一水分条件下,空地上青冈栎和茶条木的SPAD值总高于黄荆条树冠下;各水分条件下,青冈栎和茶条木的相对邻接效应指数(RNE)都为负值,且随水分增大RNE的绝对值越大。因此,先锋灌木黄荆条对其树冠下的青冈栎和茶条木幼苗生长起到抑制作用,且这种抑制作用随着水分条件改善而增强。
In order to select suitable species to optimize and improve the structure of pioneer community in karst rocky desertification area, this paper uses potted water control experiment to test the effects of Pioneer shrubs Vitex negundo on the seedlings of Cyclobalanopsis glauca and tea tree under the different water conditions. The results showed that the relative growth rate of C. glauca and M. officinalis seedlings increased with the improvement of water conditions, both under the canopy of Crown euphorbia villosum or on the open ground. Under the same water conditions, The growth rate was always lower than that of open space, and the difference gradually increased with the increase of water content. The relative chlorophyll content (SPAD) in the leaves of Quercus glauca increased obviously with the increase of water content under the canopy, Under the same water condition, the SPAD value of Cyclobalanopsis glauca and Camellia wood in the open space was always higher than that under the canopy of Vitex negundo. Under the condition of the same water, under the same water condition, The relative adjoining effect index (RNE) of both Cyclobalanopsis glauca and Chatiao wood was negative, and the absolute value of RNE increased with the increase of water content. Therefore, Phellodendron cv. Vulgaris inhibited the growth of the Quercus glauca and Podocarpus sylvestris seedlings under its canopy, and this inhibition increased with the improvement of water conditions.