猫儿山三种森林类型林下植物叶片与土壤化学计量特征

Stoichiometric characteristics of understory plant leaves and soil of three forest types in Mao'ershan

关键词:  猫儿山, 森林类型, 土壤, 草本层, 灌木层, 化学计量特征

Key words:  Mao'ershan, forest type, soil, herb layer, shrub layer, stoichiometric characteristics

摘要:

为探究猫儿山不同森林类型林下植物叶片与土壤化学计量特征,揭示其林下植物适应策略。该文对猫儿山针阔混交林(ZK)、常绿阔叶次生林(CLC)和常绿阔叶林(CL)林下草本层和灌木层主要植物叶片与土壤的化学元素含量进行测定,分析其化学计量特征及其相互之间的内在联系。结果表明:(1)从总体上看,草本层和灌木层植物叶片的C、N含量差异不显著,草本层植物叶片P、K含量极显著高于灌木层,N:P显著低于灌木层; 草本层植物更易受N限制,灌木层植物更易受P限制且其N和P利用效率更高; 不同森林类型之间的灌木层植物叶片化学计量差异不显著,草本层植物叶片N含量、C:N和C:P差异显著,针阔混交林草本层植物的养分利用效率较高。(2)3种森林类型的土壤C、N含量显示,CL>CLC>ZK且彼此之间差异极显著,针阔混交林土壤的P含量最高而C:P、N:P最低。(3)针阔混交林的土壤显著影响林下植物部分叶片化学计量,另外2种森林类型的土壤影响不显著。综上认为,猫儿山不同森林类型的土壤化学计量存在显著或极显著差异,林下不同层次的植物对营养元素的需求以及环境适应策略不同; 针阔混交林土壤对林下植物叶片化学计量影响较强,由于有机质分解效率较低导致土壤受N限制,因此应加强针阔混交林的N素管理。该研究结果为森林管理提供了数据支持。

Abstract:

Exploring the stoichiometric characteristics of understory plants' leaves and soils in different forest types in Mao'ershan can reveal the adaptation strategies of understory plants in Mao'ershan, and provide data support for forest management. In this paper, coniferous and broad-leaved mixed forest(ZK), evergreen broad-leaved secondary forest(CLC)and evergreen broad-leaved forest(CL)in Mao'ershan were selected as three forest types, the leaf stoichiometry of main plants in herb layer and shrub layer, and the soil stoichiometry under three forest types were measured and analyzed. The results were as follows:(1)There was no significant difference in leaf C and N contents between herb layer and shrub layer, but P and K contents in herb layer were extremely significantly higher than that in shrub layer, and N:P was significantly lower than that in shrub layer. Plants in herb layer was more likely to be restricted by N, plants in shrub layer was more likely to be restricted by P and the utilization efficiency of N and P were higher. There was no significant difference in leaf stoichiometry of plants in shrub layer among different forest types, but there were significant differences in leaf N content, C:N, C:P of plants in herb layer among different forest types. Plants in herb layer of ZK had higher nutrient use efficiency.(2)The soil C and N contents of the three forest types showed that CL > CLC > ZK, and there were extremely significant differences among the three forest types. The soil P content of ZK were the highest, while that of C:P and N:P were the lowest.(3)Soil in ZK significantly affected some leaf stoichiometry of plants in herb layer and shrub layer, while the other two forest types had no significant effect on underforest plants. To sum up, there are significant or extremely significant differences in soil stoichiometry among different forest types in Mao'ershan. The nutrient requirements and environmental adaptation strategies of plants in herb layer and shrub layer are different. The soil of ZK has a strong influence on the leaf stoichiometry of understory plants, and the soil with low decomposition efficiency of organic matter in this forest type, and the soil is limited by N due to the low decomposition efficiency of organic matter, so the management of N in the mixed forest should be strengthened.