科尔沁沙地4种生境地土壤种子库特征及其与土壤化学因子的关系

Characteristics of Soil Seed Banks and Their Relationships with Soil Chemical Factors in Four Habitats in Horqin Sandy Land

[目的]探究科尔沁沙地4种生境下的土壤种子库特征及其与土壤化学因子的关系。[方法]以科尔沁沙地4种不同演替阶段下的生境(农田地区、弃耕地区、自然草地区、林间草地区)为研究对象,通过野外调查取样及室内种子萌发相结合的方法,研究不同生境下瞬时土壤种子库的组成、空间分布以及与土壤化学因子之间的关系。[结果]4种生境地土壤种子库共计出现11种植物,分为6科11属,种子库组成较为简单,多为一年生植物。不同生境地土壤种子库密度有显著差异(P<0.05),表现为自然草地区>林间草地区>农田地区>弃耕地区,且在相同生境垂直方向上密度均呈递减趋势。4种生境地土壤种子库中Simpson指数、Shannon-Wiener指数变化趋势基本一致,均表现为自然草地区最高,农田地区最低;农田地区和林间草地区的种子库相似性最高,为0.88,自然草地区和弃耕地区相似性最低,为0.46。土壤种子库多样性指数与速效钾、有效磷呈正相关,与有机质、碱解氮呈负相关。[结论]该研究结果为科尔沁沙地植被的恢复与重建提供理论依据。

[Objective]To explore the characteristics of soil seed banks and their relationships with soil chemical factors in 4 habitats in Horqin Sandy Land.[Method]Taking four habitats under different succession stages in Horqin Sandy Land(agricultural area,abandoned farming area,natural grass area,and forest grass area)as the research object,the composition and spatial distribution of instantaneous soil seed banks in different habitats and their relationship with soil chemical factors were studied through a combination of field survey sampling and indoor seed germination.[Result]There were 11 kinds of plants in the soil seed banks of 4 habitats,which were divided into 6 families and 11 genera.The composition of the seed bank was relatively simple,mostly annual plants.The density of soil seed banks in different habitats had significant difference,which was natural grassland area>forest grass area>farmland area>abandoned area,and the density of soil seed banks in the same habitat showed a decreasing trend in the vertical direction.The Simpson index and Shannon-Wiener index in the soil seed banks of the four habitats were basically the same,with the highest in the natural grass area and the lowest in the farmland area.The similarity of seed banks in farmland area and forest grass area was the highest,which was 0.88,and that in natural grassland area and abandoned area was the lowest,which was 0.46.The density of soil seed banks was positively correlated with available potassium and available phosphorus,and negatively correlated with organic matter and alkali hydrolyzable nitrogen.[Conclusion]The results of this study provide a theoretical basis for the restoration and reconstruction of vegetation in Horqin Sandy Land.