关键词: 叶茎比, 养分富集, 养分回收度, 养分利用策略, 物种组成

Abstract:

Nutrient resorption is a crucial component of plant nutrient use strategy, yet the controls on the responses of community-level nutrient resorption to altered nutrient availability remain unclear. Here, we addressed two questions: (1) Did leaf and stem nutrient resorption respond consistently to increased nutrient availability? (2) Was community-level plant nutrient resorption response after nutrient enrichment driven by the intraspecific plasticity in plant nutrient resorption or by altered species composition?

We investigated the changes in aboveground biomass, and leaf and stem nutrient resorption of individual species after 3-year nitrogen (N) and phosphorus (P) additions, and assessed community-level nutrient resorption response to 3-year nutrient additions in a graminoid-dominated temperate wetland, Northeast China.

For both leaves and stems, N and P additions did not affect nutrient resorption efficiency, but they decreased respective nutrient resorption proficiency. Similarly, community-level N and P resorption proficiency declined with respective nutrient addition. Community-level N and P resorption efficiency was reduced by N addition primarily due to altered community composition and declined leaf:stem ratio. These results suggest that leaf and stem nutrient resorption processes exhibit consistent responses to increasing nutrient availability in the temperate wetland. These findings highlight the importance of altered species composition and biomass allocation between leaf and stem in driving community-level nutrient resorption response to nutrient enrichment.

Key words: leaf:stem ratio, nutrient enrichment, nutrient resorption proficiency, nutrient use strategy, species composition