Litter facilitates plant development but restricts seedling establishment during vegetation regeneration

Abstract

Abstract Rapid vegetation regeneration and increased litter production have been predicted under the global greening scenario, but the overall relationship between litter production and vegetation regeneration has not been well addressed. To bridge this knowledge gap, we quantified the responses of the seed stage, seedling stage, plant development stage and vegetation community to litter using 3193 paired observations at the global scale based on the effect size across different categories. Overall, litter significantly decreased seedling establishment and density by 28.4% and 27.7%, increased plant height by 17.4% and decreased species richness by 15.4%. Seed germination at the seed stage was not directly controlled by litter but was positively regulated by changes in soil moisture from litter. In contrast, litter type and litter mass displayed negative effects on the seedling stage, but litter promoted seedling survival with increasing elevation. Moreover, litter composition and plant type dominated the effects of litter on the plant development stage, showing that the increase in litter production might favour the development of broadleaved trees rather than other plants. The present results suggest that litter could restrict the stage from seed to seedling but facilitate plant development after the seedling establishment and slightly affect the vegetation community except for species richness. These results provide deep insight into the relationships between litter production and vegetation regeneration at different stages, which are important for developing models accounting for vegetation regeneration responses to ongoing global greening. Read the free Plain Language Summary for this article on the Journal blog.