Trade-offs in survival strategies: root trait differentiation of trees and shrubs on the Jingpo Lake lava platform

To investigate the adaptive strategies of root functional traits in woody plants of different life forms on the Jingpo Lake lava platform towards heterogeneous habitats and provide reference for vegetation restoration strategies on lava platforms, this study examined 16 common woody plant species (12 trees and four shrubs) on the Jingpo Lake lava platform and measured the morphology and chemical properties of their primary to tertiary roots to investigate differences in root functional traits among plants of varying life forms. Trees and shrubs had the greatest variation in specific root length (SRL) (55.55 %-71.46 %) and the least variation in root carbon content (RCC), with all values below 5 %. Root diameter (RD), RCC and root carbon to nitrogen ratio (RC/N) for 1-3 order roots, and specific root surface area (SRA) for second-order roots were greater for trees compared with those for shrubs. Only the first-order root trait exhibited significant differences. Principal component (PC) 1 and PC2 of 1-3 order roots cumulatively explained 72.10 %, 71.60 %, and 67.20 % of the variance, respectively. Each sequence axis of first and second-order roots was positively correlated with SRL and SRA, and the third-order roots were negatively correlated with these traits. The soil total potassium content (STKC), soil total phosphorus content (STPC) and soil rapidly available phosphorus content (SAPC), had the greatest effect on plant root morphological traits. The findings suggest that in this study area, trees are more likely to adopt resource-conserving survival strategies, whereas shrubs tend to adopt resource-acquiring strategies.