高级检索+

胡杨繁殖根扩展行为及其影响因子研究

Study on the foraging behavior of clonal roots and its influencing factors in Populus euphratica Oliv.

  • 摘要: 以天然林异质环境下胡杨(Populus euphratica Oliv.)克隆繁殖根的近、远端根为研究对象,在胡杨林自然保护区选取5个样地,采用典型抽样法对共25个完整的繁殖根分支以及对应的环境因子进行调查,分析其近、远端根扩展行为差异及环境影响因子。结果显示:胡杨繁殖根近端根的主根分布深度、主根直径、主根长度显著大于远端根;而细根生物量、萌蘖点密度显著少于远端根。繁殖根近、远端根主根长度均与土壤全磷呈正相关;近端根直径与土壤全碳含量呈正相关,土壤含水率、邻近根系生物量对近端根萌蘖点密度有正向作用;远端根深度与土壤紧实度、邻近根系生物量呈负相关,而细根生物量主要受土壤含水率、土壤全氮含量、邻近根系生物量与土壤紧实度的正向影响。研究结果表明胡杨繁殖根通过增大近端根长度与直径来提高其碳存储与寻找适宜环境的能力,同时增加远端根的细根生物量与萌蘖点密度以实现养分获取和产生分株。

     

    Abstract: We investigated differences in foraging behavior of the proximal and distal roots of Populus euphratica Oliv. in a heterogeneous natural forest habitat and estimated the key influencing factors of foraging behavior traits, including main root depth (MRD), root diameter (RD), main root length (MRL), fine root biomass (FRB), and root sucker density (RSD). In total, five sample plots were established in Ejin Oasis, Inner Mongolia, and Northern China. A total of 25 clonal root branches were manually excavated and corresponding belowground environmental factors were analyzed. Results showed that the MRL, RD, and MRL values were significantly higher for proximal roots than for distal roots, whereas the FRB and RSD values were significantly lower. Soil total phosphorus had a major positive influence on the MRL of clonal roots. The RD values of proximal roots increased with soil total carbon, and RSD values were positively controlled by soil water content and biomass of neighbor root. Soil compaction and biomass of neighbor root had negative effects on the MRD of distal roots. Soil water content, soil total nitrogen, biomass of neighbor root, and soil compaction had positive effects on the FRB of distal roots. Thus, our results indicate that clonal roots improve C-storage ability and locate better environments by increasing the MRL and RD of proximal roots and improve nutrient acquisition and ramet production by increasing the FRB and RSD of distal roots.

     

/

返回文章
返回