Abstract: We elucidated the changes in larch fine root (diameter <2 mm) traits and environmental factors in 5 sites across a latitudinal gradient in China, linking the fine root morphological traits (e.g. mean root length, mean root diameter, specific root surface area (SRA) and specific root length (SRL) with climate and soil factors. Along with the increase in latitude, the mycorrhizal fungal infection rates of the first and second order roots decreased clearly, the numbers of ectomycorrhizas forks increased and color became darker, and the mean root diameter and root length got smaller, while the SRL and SRA got larger. Furthermore, there was a significant positive correlation between root diameter, length and mean annual precipitation (MAP), mean annual temperature (MAT) and soil water content. Also, a strong positive correlation was observed between SRL, SRA and soil TC, soil nutrients. The results of our study demonstrated that both ECM and noninfested fine root had clear morphological plasticity across a latitude gradient, and ECM morphological traits varied with sitespecific characteristics, and root diameter and root length were mainly affected by climatic factors, whereas SRA and SRL were mainly modified by soil factors.

Key words: Xi’an City, normalization of temperature, heat island prediction, landscape pattern