Autumn nutrient resorption and twig storage shape spring phenology in woody species

Nutrient resorption from leaves and translocation to twigs and other woody tissues during leaf senescence is a crucial strategy for plant nutrient conservation. The nutrients retained in twigs provide essential resources for new growth, especially when root nutrient acquisition is restricted by low soil temperatures during early spring. However, the interconnections between leaf nutrient resorption and twig nutrient accumulation during autumn, and their influence on spring phenology, remain poorly understood.

We selected 20 woody species with a wide range of leaf traits in a common garden and investigated the relationships among leaf resorption efficiency, twig accumulation efficiency of nitrogen (N) and phosphorus (P), and autumn‐spring phenology.

We found that leaf N resorption (54.27%) was significantly higher than leaf P resorption (42.42%). Additionally, twig N accumulation efficiency (40.00%) was significantly higher than twig P accumulation (18.37%), with both positively correlated with leaf nutrient resorption efficiency. Species with acquisitive traits exhibited higher N and P resorption efficiency, along with higher P accumulation efficiency in twigs. Soil fertility had a relatively minor influence on both leaf nutrient resorption and twig nutrient accumulation. In addition, autumn and spring phenological events were linked to plant internal nutrient dynamics. Species with later leaf shedding and shorter leaf fall duration in autumn tended to exhibit greater leaf P resorption efficiency. Furthermore, species with higher twig nutrient accumulation efficiency showed earlier bud break and a longer period of leaf‐out in the subsequent spring. Modular network analysis and structural equation model further indicated that leaf nutrient resorption was strongly related to leaf economic traits, while leaf nutrient resorption was indirectly linked to bud‐break timing through twig nutrient accumulation.

Synthesis . Our findings suggest that plant internal nutrient dynamics are not only consequences of phenology but may also influence phenological timing. These results highlight the importance of nutrient resorption and storage strategies in regulating seasonal growth patterns and indicate that internal nutrient cycling may affect plant performance and ecosystem functioning under varying environmental conditions.