皖江滩地杨树抑螺防病林下植物多样性分析

以时空互代的方法,对皖江段滩地不同林龄的杨树人工林林下植物多样性进行了调查。结果表明:①杨树人工林林下以草本植物为主,居于前4位的优势科分别是菊科(9种)、禾本科(6种)、豆科(5种)、蓼科(5种),优势种以萝藦、菱叶鹿藿、无辣蓼、葎草为主。木本植物有桑科桑树、蔷薇科野蔷薇;②滩地造林后,林下植物的丰富度、多样性指数、均匀度指数均高于无林滩地上以芦苇为主的群落;③随着人工林林龄的增加,多样性指数表现出了先降低后上升的趋势,3年生的人工林丰富度(S)、多样性指数(D,H′)最高,20年生的人工林均匀度指数最高。滩地造林后植物多样性有一定程度增加,但成林后植物多样性又逐年减少。

Plant Diversity Under Poplar Plantations in Yangtze River Beach in Anhui

A survey was conducted using spatial analysis on plant diversity under poplar plantations at different ages growing in Yangtze River beach in Anhui. The results showed that: Herbaceous plants dominated under poplar plantations. The top four dominant families were Asteraceae (9 species), Gramineae (6 species), Leguminosae (5 species), Polygonaceae (5 spcecies). The dominant species were mainly Metaplexis japonica, Rhynchosia dielsii, Polygonum pubescens, Humulus scandens. Woody plants were only Morus alba of Moraceae and Rosa multiflora of Rosaceae. The species richness, diversity index and evenness index of the understory plants were all higher than those of the reeds-dominated community in non-forested river beach. With the increase of plantation age, the diversity index of understory plants tended to decrease first and followed by an increase. The understory species richness and diversity index of were the highest in 3-year-old plantation, while the evenness index was the highest in 20-year-old plantation. Therefore, the plant diversity somehow increased after afforestation in the beach, but decreased when the plantation become mature.