红壤侵蚀区马尾松林下植被特征与土壤侵蚀的关系

针对南方花岗岩发育的红壤侵蚀区,在赣县大田乡选择5个低丘马尾松林,利用植物样方调查方法对样地的地形、土壤、植被、侵蚀沟进行调查和测量,基于获取的数据,利用统计学方法分析植被特征与土壤侵蚀的关系.结果表明：1）马尾松人工林郁闭度低,林木生长状况差,林地阳坡半阳坡植被总盖度仅为36.9％;2）林下灌草生物量低,物种丰富度、多样性、均匀度差,物种较为单一;3）林下植被以草本为主,草本以芒萁为主,其生物量占草本总生物量的75％以上;4）马尾松林下细沟、浅沟发育,土壤侵蚀严重,仅细沟、浅沟流失的土壤厚度达71.2 mm;5）不同坡位的侵蚀沟发育相关性显著,侵蚀沟与坡面的微环境差异明显,尤其是土壤密度和土壤水分差异显著;6）马尾松林下土壤侵蚀量对植被恢复具有抑制作用,但沟壑密度的发育能够提高灌草物种丰富度、多样性,以及促进灌草均匀性分布.

Relationship between vegetation and soil erosion under Pinus massoniana forest in eroded red soil region of southern China

Vegetation is a factor influencing soil erosion significantly,as in turn soil erosion has great impacts on vegetation restoration.Pinus massoniana forests in eroded red soil region of southern China are subject to scarce undergrowth and severe soil erosion.It is therefore of great importance to study the relationship between undergrowth features and soil erosion in order to reveal the soil erosion process and the vegetation restoration mechanism of P.massoniana undergrowth.This study selected five hilly P.massoniana forests in Datian Town of Ganxian County in the eroded red soil region developed from granite in southern China.Each hill was surveyed along one belt transect from the upper to lower slope.There were totally five belt transects and fifteen sample plots of 10 m × 10 m.The investigation and measurement of landform,soil,vegetation and erosion gully were carried out in each sample plot.The relationship between vegetation features and soil erosion was analyzed statistically based on the observed data.The results showed：1） The canopy density of P.massoniana forest in the eroded red soil region developed from granite was at a low level; the growth of woods was in poor condition and the total vegetation coverage was only 36.9％.2） The undergrowth biomass of shrubs and herbs were low,and the richness,diversity and homogeneity were limited as well.3） The undergrowth vegetation is mainly herbs dominated by Dicranopteris dichotoma whose biomass amounted for over 75％ of the total herbs.4） Rill and shallow gully erosions were serious which had a soil loss of 71.2 mm thick per unit area.5） The development of eroded gullies and slope position were significantly correlated.There was a marked difference in micro environment between eroded gullies and slopes,especially in terms of soil density and moisture.6） The soil erosion amount under P.massoniana forests has an inhibitory effect on the vegetation restoration,while the growth of gully density increases the richness,diversity and uniformity of shrub