滇南地区普洱茶树根系对土壤优先路径形成的影响

Effect of Root of Pu’er Tea on the Formation of Soil Priority Path in Southern Yunnan

为明确滇南地区普洱茶种植下土壤优先路径特征以及根系对其形成的影响,以典型普洱茶产地为研究对象,灌草地为对照,基于染色示踪法与图像处理技术,定量分析普洱茶树根系特征与土壤优先路径的关系,解释根系对优先路径形成的影响。结果表明:(1)茶地和灌草地染色路径宽度随土层深度增加呈不同幅度的下降趋势,茶地优先路径的连通性比灌草地差,优先路径的发育程度小于灌草地;(2)根系主要集中分布在土壤表层,随土层深度增加,根重密度、不同径级根长密度均呈减小趋势,径级≤1 mm的根长密度贡献度最大,达到84.08%;(3)染色路径宽度与根重密度、径级≤1,1~3 mm的根长密度呈显著相关(P<0.05),其中灌草地染色路径宽度与径级≤1 mm的根长密度呈极显著相关性(P<0.01),相关系数为0.986;(4)染色路径宽度与径级≤1 mm的根长密度拟合效果较好,R^(2)高达0.9706,径级≤1 mm的细根系对优先路径形成的影响程度更大。根系是影响土壤优先路径的重要因素之一,开展滇南地区普洱茶树根系对土壤优先路径影响的研究,可为当地水土流失治理以及水资源管理提供一定的科学依据。

In order to clarify the characteristics of soil priority path and the influence of root on the formation of soil priority path under the cultivation of Pu'er tea in southern Yunnan,we took the typical Pu'er tea producing areas as the research object and shrub grassland as the control,and the relationship between root characteristics of Pu'er tea tree and soil priority path was quantitatively analyzed based on the staining tracer method and image processing technology,and the influence of root on the formation of soil priority path was explained.The results showed that:(1)With the increasing of soil depth,the width of dyeing path in tea field and shrub grassland decreased in different extent.The connectivity of priority path in tea field was worse than that in shrub grassland,and the development degree of priority path in tea field was less than that in shrub grassland.(2)The root mainly distributed in the surface of soil,with the increasing of soil depth,root weight density and root length density of different diameter classes all decreased,and the root length density of diameter class ≤1 mm contributed the most,reaching 84.08%.(3)The width of staining path was significantly correlated with root weight density,root length density of diameter class ≤1 mm and 1~3 mm(P<0.05).The width of staining path of shrub grassland was significantly correlated with root length density of diameter class ≤1 mm(P<0.01),and the correlation coefficient was 0.986.(4)The staining path width had a better fitting effect with the root length density of diameter class ≤1 mm,and the R^(2) was as high as 0.9706.The fine roots with diameter class ≤1 mm had a greater influence on the formation of priority path.Root is one of the important factors that affect soil priority path.The research on the influence of Pu'er tea tree root on soil priority path in southern Yunnan can provide some scientific basis for soil erosion control and water resources management.