Response of fine-and shallow root traits to freeze-thaw cycle more sensitive in an alpine steppe of the Northern Tibetan Plateau

Abstract

Abstract Aims: There is compelling evidence from experiments and observations that the soil environment in the nongrowing season influences vegetation in alpine regions. The response of root traits such as morphology and anatomical and antioxidant enzyme systems to freeze-thaw cycles plays an important role in the relationship between aboveground parts and climate change. Methods: We measured functional root traits of six species by digging and growth chambers over freezing and thawing periods. Results: The uniformity of root traits was more obvious in spring than that in late autumn. Most importantly, fine-and shallow-root presented acquisitive syndromes in spring. Root morphological and anatomical traits affect freeze-thaw cycles by influencing root water and nutrient uptake. Conclusions: We therefore argue for explicit consideration of the correlation between the manipulation of freeze-thaw cycles and root traits in further. Better representation of the dynamics and characteristics of annual production and mortality of alpine roots will improve the utility of adaptive strategies for the evaluation of the responses of seasonal frozen ground ecosystems to changing environmental conditions.