The response of two nutrient acquisition strategies: root traits and leaf nutrient resorption and their relationships to long-term mowing in a temperate steppe

Purpose Mowing may exert profound influences on nutrient acquisition strategies of herbaceous species due to the nutrient removal along with the mown plants. Nutrient uptake by roots and nutrient resorption from senescent leaves, are two main nutrient acquisition strategies of perennial herbaceous species. However, few studies have considered both nutrient acquisition strategies in exploring the effects of long-term mowing on the nutrient acquisition of perennial herbs. Methods We measured root traits of absorptive roots and leaf nitrogen resorption efficiency (NRE) of seven herbaceous species with different plant height on a long-term mowing experimental platform (2003-2020) in a temperate steppe. Results We found that root traits of tall and short species had little response to long-term mowing. While, mowing exerted opposite effects on leaf NRE of the two plant groups, i.e., mowing significantly decreased the NRE of tall species, but increased that of short species (except for Potentilla acaulis). Furthermore, root absorption capacity (indicated by root traits) was positively correlated with leaf NRE for tall species in control plots, but mowing eliminated this relationship. In contrast, for short species, root traits and leaf NRE had no correlation in control plots, while, mowing led to synergic relationship between root absorption capacity and leaf resorption rates. Conclusions Our results suggested that perennial herbs changed the relationships between alternative resource acquisition strategies in response to long-term mowing in temperate steppe. These findings provide new perspectives for understanding the adaptation of herbaceous species to mowing in the temperate steppe.

Automated summary

The study measured root traits and leaf nitrogen resorption efficiency of seven herbaceous species in a long-term mowing experimental platform. The results showed that mowing had little effect on root traits of tall and short species, but exerted opposite effects on leaf nitrogen resorption efficiency of the two plant groups.