The successful establishment of seedlings is shaped by a variety of biotic and abiotic factors. In particular, increasing density of conspecific neighbors often leads to decreases in seedling survival, a phenomenon referred to as conspecific negative density dependence (CNDD). Studies have found that the strength of CNDD often varies between tree species that associate with different mycorrhizal symbionts. In addition, CNDD strength can vary among sites that differ in abiotic conditions. Using data on seedlings (< 1 cm diameter at 1.3 m above ground; DBH) and trees (≥ 1 cm DBH) from the Donglingshan 20‐ha warm temperate forest dynamics plot (FDP) in Beijing, China, we tested whether the probability of a seedling surviving was related to the density of conspecific seedling and large (≥ 1 cm DBH) neighbors, and whether the strength of conspecific neighborhood effects differed between species associated arbuscular mycorrhizae (AM) versus ectomycorrhizae (EcM) or with soil nutrient availability. Contrary to our expectation, conspecific seedling neighborhood density was positively related to seedling survival, irrespective of species mycorrhizal type. The positive effect of conspecific seedling neighborhood density on seedling survival was stronger as soil nutrient availability increased. In contrast, seedling survival decreased with increasing conspecific large neighborhood density, and this effect was more negative for AM seedlings compared to EcM seedlings, while soil nutrient availability did not influence the effect of large neighbors on seedling survival. These findings illustrate the essential roles played by neighborhood interactions, mycorrhizal type, and abiotic factors in seedling survival. CNDD in seedling survival potentially contributes to understanding the maintenance of species diversity in this temperate forest, particularly for AM species. Understanding these processes that determine species diversity holds the key to improving forest conservation and management strategies in the context of biodiversity loss.
Du et al. (Thu,) studied this question.