In tropical rainforests, seedling performance at fine ecological scales has traditionally been explained by seed dispersal limitation and negative density dependence. Strong seedling-environmental associations have been detected at local scale in previous studies.
Researchers from Xishuangbanna Tropical Botanical Garden (XTBG) sought to examine whether soil heterogeneity has a notable effect on local seedling spatial distribution, survival, and growth at a fine scale.
They surveyed seedling spatial location, survival, and growth dynamics for three years, and also monitored the nutrients and light conditions of 99 two-m2 quadrats in a one-hectare area of tropical rainforest in Xishuangbanna.
They found that heterogeneity in fine scale soil properties was sufficient to cause spatial niche differentiation among species in tropical rainforest. The fine scale seedling distribution was also associated with fine scale heterogeneity in soil properties and light.
The co-occurrence of limitations in soil properties and light conditions, retarded growth of the seedling of all species, and it did not significantly influence seedling survival, thereby having a beneficial effect of maintaining seedling diversity.
The study entitled “Fine scale heterogeneity of soil properties causes seedling spatial niche separation in a tropical rainforest” has been published online in Plant and Soil.
CHEN Jin, Ph.D Principal Investigator
Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China