片断化热带雨林土壤种子库初步研究

STUDY ON THE SIOL SEED BANKW OF FRAGMENTED TROPICAL RAIN FORESTS IN XISHUANGBANNA

通过萌发实验研究片断化热带雨林的森林土壤种子库的储量、种类组成以及种子的分布。结果表明 ,在厚度为 1 0cm的土壤中 ,受次生植被隔离的城子龙山雨林片段土壤种子库储量达到 6494± 1 55粒 m2 ,高于连续森林的 4 585± 2 35粒 m2 。而受人工植被隔离的曼仰广龙山雨林片段由于缺乏种源 ,土壤种子库储量较低 ,仅达到 350 5± 4 3粒 m2 。土壤种子库中的种子种类也以城子龙山为最多 ,达到 69种。从土壤种子库的水平分布看 ,受次生植被影响的城子龙山和迁地保护区从林缘至林内种子储量呈下降的趋势 ,而需子龙山隔离程度较高、受人畜干扰严重 。

This paper deals with the soil seed banks of tropical fragmented rain forests in Xishuangbanna by germination trials. Two stands of fragmented rain forests on holy hills of Dai Nationality,one stand from the ex-situ conservation reserve of Xishuangbanna Tropical Botanical Garden and one from the Menglun Nature Reserve were chose for the study. Twenty five soil samples (10×10×10 cm 3 each)were collected for the germination experiment from each sites. Chengzi holly hill,which is surrounded by secondary forests,has the highest seed storage of 6494±155 seeds/m2 with 69 species presented in the soil seed bank. Manyangguang holy hill, which surrounded by rubber plantations,maintains the lowest seed storage of 3505±43 seeds/m 2 with only 48 sppecies presented in the soil seed bank. The EX-situconservation site, which has a larger area and less disturbance ghan the two holy hills,has a seed storage (4856±78 seeds/m 2) closed to ghat of the Nature Reserve (4585±235 seeds/m 2). The ex-situ conservation reserve and the Chengzi holy hill have a higher seed storage on the edge of the forest due to the seed sources of the secondary forest nearby. However, the Manyangguang holy hill,which ys relatively isolated by rubber plantation and suffers severe disturbance by villagers, has lower seed storage on the forest edge.