降水变化驱动下红松阔叶林土壤真菌多样性的分布格局

Effects of precipitation variation on the distribution pattern of soil fungal diversity in broad-leaved Korean pine mixed forest

红松阔叶林生态系统是中国东北地区地带性顶极植被,具有重要的生态学意义,长白山是研究温带森林对大气降水变化正负反馈的理想地带.本文以长白山原始红松阔叶林为研究对象,基于末端限制性片段长度多态性分析技术,分析了降水控制样地(增、减30%)和对照样地的0～5 cm和5～10 cm表层土和红松根际土真菌多样性的空间异质性.结果表明:降水的增加和减少均能提高土壤真菌的多样性,但优势种群有所变化.表层土中,片段长度超过500 bp的T-RFs丰度随降水增加而提高,根际土中对降水变化响应的T-RFs分别为380、455和487 bp,且根际土的响应模式较表层土复杂.典范对应分析结果表明,土壤pH、有机碳含量、总氮和有效磷等对真菌群落组成影响显著.

Broad-leaved Korean pine mixed forest is cal significance in Northeast China, whereas Changb a kind of zonal climax vegetation with ecologiai Mountain is an ideal area to study the effects of precipitation variation on temperate forest. Taking the virgin broad-leaved Korean pine mixed forest in Changbai Mountain as the object, and based on T-RFLP method, this paper analyzed the spatial heterogeneity of fungal diversity in 0-5 cm and 5-10 em soil layers and in rhizosphere soil at three different precipitation plots （30% increase, 30% decrease, and the control）. Both the increase and the decrease of precipitation increased the diversity of soil fungi, but the dominant population changed. In 0-5 cm and 5-10 cm soil layers, the T-RFs over 500 bp increased with precipitation; in rhizosphere soil, the T-RFs responded to precipitation variation were 380 bp, 455 bp, and 487 bp, and the response mode was more complicated than that in surface soil layers. The results of CCA showed that the fungal community composition was significantly affected by soil pH, organic carbon, total nitrogen, and organic phosphorus.