雷州半岛崩岗区不同植被重建模式下林下植物多样性分析

Effects of Vegetation Reconstruction with Different Tree Species on Understory Plant Diversity in Benggang Area of Leizhou Peninsula

为了对比以外来树种和乡土树种进行植被重建对崩岗区林下植物多样性的影响,本研究以雷州半岛典型崩岗区——广东三岭山国家森林公园为研究样地,在外来树种大叶相思林和乡土树种樟树林内分别建立10个20 m×20 m样方,在样方内进行每木调查,在每个样方的四角及中心建立5个2 m×2 m小样方,对小样方内的林下植物的种名、株数、盖度等进行记录。结果表明:大叶相思林林下植物有14科19属19种,樟树林则有15科29属29种;大叶相思林林下植物的优势种为芒,樟树林的为阔叶丰花草;大叶相思林林下植物均匀度指数、Shannon-Wiener指数和Simpson指数均显著低于樟树林(P<0.05)。从提高林地郁闭度的角度出发,可选种速生先锋树种;从提高林下植物多样性出发,可优先选择乡土树种。

This study was conducted in Leizhou Peninsula to compare the effects of exotic and native tree species on understory plant diversity in Bengang area after vegetation reconstruction. The study site is a typical Bengang area located in Guangdong Three Ridge Mountain National Forest Park. Surveys were conducted in stands of the exotic tree species Acacia auriculiformis and of the native tree species Cinnamomum camphora, with 10 plots of size 20 m × 20 m established for each species. Five subplots, each 2 m × 2 m, were set up at the four corners and center of each main plot, and understory species contained in these were examined to record species names, plant numbers and coverage in the subplot. The results showed that there were 19 species representing 19 genera and 14 families of understory plants in the A. auriculiformis stand, and 29 species representing 29 genera and 15 families in the C. camphora stand. The dominant species were Miscanthus sinensis in the A. auriculiformis stand and Borreria latifolia in the C. camphora stand. The evenness index, Shannon-Wiener index and Simpson index of the understory in the A. auriculiformis stand were significantly lower than those of the understory in the C. camphora stand(P<0.05). In order to improve the canopy density of forestland, fast growing exotic pioneer tree species such as Acacia can be selected, but in order to improve understory plant diversity, native tree species should be selected first.