不同伐藤处理下次生林群落土壤种子库特征及演替趋势

Characteristics and Succession Trend of Soil Seed Bank in the Next Forest Community Treated with Different Cutting Vines

本研究以五指山市受藤本植物危害严重的低海拔次生林群落为研究对象,采用野外植被调查和室内种子萌发试验相结合的方法,对不同伐藤处理下的次生林群落土壤种子库特征、物种多样性及其与林下植被的相似性进行了研究。结果表明:(1)人工除藤可提高研究区土壤种子库种子萌发数量及速度,也可延长其种子萌发天数;(2)不同伐藤处理下的土壤种子库中共出现74种植物,隶属35科67属,其中菊科、茜草科和禾本科植物种出现比例较高,而飞机草在不同伐藤处理下的土壤种子库中均为优势种;不同伐藤处理下的土壤种子库物种生活型组成,均以草本植物占明显优势,人工除藤可使土壤种子库中乔木、灌木等生活型的物种数明显增多;(3)不同伐藤处理下土壤种子库种子密度和物种数均随土层深度的加深呈递减趋势,人工除藤可使研究区2~5、5~10 cm土层土壤中的种子密度明显增加;(4)不同伐藤处理下土壤种子库物种多样性指数均无显著差异,且其土壤种子库与林下植被的相似性系数(0.173~0.302)普遍较低,但随着伐藤年限的延长,土壤种子库与林下植被物种组成的相似性增大,伐藤3年处理的群落显著大于未做处理的对照群落。综上可知,人工除藤可提高研究区土壤种子库的植被恢复潜力及天然更新能力,有助于推动该区域次生林群落的正向恢复演替。

In this paper, the low-altitude secondary forest community with serious damage to vines in Wuzhishan City were used as the research object. The combination of field vegetation survey and indoor seed germination test was used to analyze the soil seed bank characteristics and species diversity of secondary forest communities under different vines. Its similarity with the understory vegetation was studied. Artificial vine removal could increase the seed germination quantity and speed of the soil seed bank in the study area, and also prolong the seed germination days. A total of 74 plants were found in the soil seed bank under different vines treatments, belonging to 67 genera in 35 families, among which the proportions of Asteraceae, Rubiaceae and Gramineae were higher, while the Eupatorium odoratum were dominant species in the soil seed bank under different vines treatment. The composition of life type was dominated by herbaceous plants. Artificial vine removal could increase the number of species of trees and shrubs in the soil seed bank. The seed density and species number of soil seed bank under different vines with the deepening of the depth of the soil layer, the seed density in the soil of 2–5 and 5–10 cm soils in the study area increased significantly. There was no significant difference in the species diversity index of soil seed bank under different vines treatments, and the similarity coefficient(0.173–0.302) between soil seed bank and understory vegetation was generally lower. However, with the extension of the age of cutting vines, the similarity of soil seed bank and understory vegetation species composition increased, and the community treated by vine for 3 years was significantly larger than the untreated community. In summary, artificial vine removal can improve the recovery potential of vegetation and improve the natural regeneration ability of the soil seed bank in the study area, and help to promote the positive recovery succession of the secondary forest community in the area.