黑龙江省西部主要草地类型土壤和植被特征

Study on soil and vegetation characteristics of main grassland types in western Heilongjiang Province

摘要:

【目的】明确松嫩平原未退化草地土壤与植被现状，为松嫩平原天然草原生态系统保护及草原可持续利用提供科学依据。【方法】在黑龙江省西部选取松嫩平原草原区域内的杜蒙、林甸和肇东等县市典型未退化围栏封育天然草原进行样地调查分析，研究草原群落组成、土壤特征变化情况，分析二者之间的关系。【结果】根据立地类型和植被特征，将未退化天然草原划分为温性草甸草原和低地草甸；温性草甸草原的群落物种数、丰富度指数、香农威纳指数均高于低地草甸，上、中、下层群落分布较均匀；低地草甸土壤 pH 值和电导率普遍高于温性草甸草原，土壤容重低于温性草甸草原。温性草甸草原的地上生物量、土壤全氮和有机质含量普遍低于低地草甸。土壤含水率与物种数、丰富度指数显著负相关性（P＜0. 05）。【结论】松嫩平原天然未退化典型草原的群落盖度仍保持较高水平，群落密度受表层土壤养分的影响较大；地带性温性草甸草原的物种多样性要优于非地带性的低地草甸，但土壤养分状况不及低地草甸。

关键词:松嫩平原;温性草甸草原;低地草甸;群落构成;土壤全氮;有机质含量

Abstract:

【Objective】The aim of the study is to clarify the soil and vegetation status of undegraded grassland in Songnen Plain，and provide scientific basis for the protection of natural grassland ecosystem and sustainable use of grassland in Songnen Plain.【Method】 In this study，the typical natural grassland of enclosure in Dumeng，Lindian and Zhaodong of the Songnen Plain in western Heilongjiang province was selected for sampling analysis within the quadrat，The community composition，changes of soil characteristics were also investigated and，the relationship be- tween community composition and soil characteristics were analyzed.【Result】 According to the site type and vegeta- tion characteristics，the undegraded natural grassland was divided into temperate meadow grassland and low-land meadow. The results showed that species number，richness index and Shannon -Wiener index of temperate meadow grassland were higher than those of low-land meadow. The distribution of upper，middle and lower communities was uniform. The soil pH value and conductivity of low - land meadow were generally higher than those of temperate meadow grassland. Soil bulk density was lower than that of temperate meadow grassland . The aboveground biomass， the contents of total nitrogen and organic matter of temperate meadow grassland were generally lower than those of low-land meadow . Soil moisture content was negatively correlated with species number and richness index. 【Conclusion】 The community coverage of natural non - degraded typical steppe in Songnen Plain was still at a high level，and the community density was greatly affected by surface soil nutrients. The species diversity of zonal temper- ate meadow grassland was better than that of non-zonal low-land meadow，but the soil nutrient status was lower than that of low-land meadow.

Key words:Songnen Plain;temperate meadow grassland;low-land meadow;community composition;total nitro- gen;content of organic matter