开封地区不同土地利用形式下春季土壤杂草种子库格局及生物多样性

The Pattern and Biodiversity of Soil Weed Seed Banks under Different Land Use Forms in Spring in Kaifeng Area

研究了开封地区5种土地利用形式（草坪、小麦地、苗圃、梨园、荒地）下春季土壤杂草种子库的物种组成、垂直分布格局和物种多样性,调查了0～20cm土层中杂草种子库的萌发发芽数,分析了杂草种子库的相似度.结果表明：5种土地利用形式下土壤（0～20cm土层）杂草种子库共有杂草种类9科13种,其中禾本科、桑科和菊科杂草种类最多,草坪中禾本科的狗牙根（Cynodon dactylon（33.54%））为优势物种;桑科葎草（Humulus scandens）在麦地、荒地和苗圃中是优势物种（87.16%、81.23%和62.20%）;梨园中菊科的鳢肠（Eclipta prostrata）最多（57.97%）.功能群分析表明：双子叶多年生杂草种子D2为主要类群,双子叶一年生植物D1主要分布在草坪、梨园和苗圃地,单子叶一年生植物M1主要分布在草坪.垂直分布格局：多度平均值1.5（0～5cm）〉1.23（5～10cm）〉1.07（10～15cm）〉0.85（15～20cm）;杂草物种丰度平均值3.36〉2.96〉2.68〉2.04.多样性指数（F=9.23,P=0.00）和优势集中度指数（F=6.89,P=0.00）在不同土地利用形式下差异显著,均匀度指数差异不显著.苗圃和草坪相似度最高,梨园和荒地相似度最低.

Species composition, vertical distribution pattern and species biodiversity of soil weed seed banks in spring of farmland were investigated under 5 land use forms in Kaifeng area. The germination numbers of soil weed seed banks were studied in the 0～20 cm soil layer. The similarity of weed seed banks was analyzed. The results showed there were 13 weed species belonging to 9 families under 5 land use forms. Poaceae, Moraceae and Asteraceae were the most three weed species. Cynodon dactylon was the dominant weed in lawn. Humulus scandens was the dominant weed in wheat, wasteland and nursery. The most Eclipta prostrata grew in pear. The results of functional group analysis showed weed seeds perennial plants D2 was the dominant group, and dicotyledonous annual plants D1 were mainly distributed in lawn, pear and nursery, while annual plants M1 were mainly distributed in lawn. The vertical distribution results showed the mean abundance and species richness decreased with the increasing soil depth： 1.5（0～5 cm）〉1.23（5～10 cm）〉1.07（10～15 cm）〉0.85（15～20 cm） and 3.36〉2.96〉 2.68〉2.04. The biodiversity indexes（F = 9.23, P =0.00）and the dominance concentration indexes（F = 6.89, P = 0.00）had significant difference under different land use forms. However, the index of evenness had no difference. There was the highest similarity in nursery and lawn, and there was the lowest similarity in pear and wasteland.