Conclusions
The root growth strategies of S. breviflora can be assessed by
two kinds of traits, one was related to root biomass, and another was
related to root morphological architecture. For S. breviflora ,
water was the most contributor to the growth of root system, and cluster
fragmentation was the second contributor, followed by N and P in order.
Under drought condition, high–level N addition induced roots ofS. breviflora developing an acquisition resource use strategy for
escaping adverse environments compared to low–level N addition; under
sufficient P condition, low–level water addition induced their roots
developing an acquisition resource use strategy for acquiring more
resource compared to high–level water addition. S. brevifloracan adjust root growth strategies of sub-clusters by cluster
fragmentation, producing smaller clusters was beneficial for improving
its adaptability in a low-N condition.