It has been widely recognized that tree species can exert a large influence on soil environment and its microflora and that these interactions in turn have considerable impact on plant growth and functioning of terrestrial ecosystems. Previous research on the effects of tree species on soil processes has focused primarily on the role of leaf litter inputs. Relatively few studies, however, have considered the importance of plant roots and their associated ecological processes. As a result, these processes influenced by plant roots have been become one of the most important but least understood ways in which plants affect nutrient cycling.

Recent research result released by Prof. Liu Qing and his colleagues may add new insights into this question. Prof. Liu’ team from Chengdu Institute of Biology CAS compared the impacts of two coniferous species (Picea asperata and Abies faxoniana) via roots on rhizosphere effects and soil N transformations and their responses to experimental warming in the Eastern Tibetan Plateau. Their results clearly demonstrated the different effects of tree species on rhizosphere processes via roots under experimental warming. The magnitudes of rhizosphere effects and soil N transformations were generally greater in P. asperata than in A. faxoniana, with P. asperata being more sensitive than A. faxoniana in response to experimental warming. Also, they pointed out that differences in root morphology (i.e., root length, root type) and activity (i.e., root exudation, fine root vigor) between two species could belargely responsible for the variation in rhizosphere processes and their responses to experimental warming.

The studies entitled “Effects of experimental warming on soil N transformations of two coniferous species, Eastern Tibetan Plateau, China” and "Nitrogen transformation in the rhizospheres of two subalpine coniferous species under experimental warming” have just been published in Soil Biology&Biochemistry (2012, DOI: 10.1016/j.soilbio.2012.03.004) and Applied Soil Ecology (2012, DOI: 10.1016/j.apsoil.2012.03.013), respectively.