Abstract:

Above- and below-ground are important components of terrestrial ecosystems. Plants and microorganisms are dependent on each other, and they are important in the linkage between above- and below-ground processes. The relationship between plants and soil microorganisms and the fundamental role played by above- and below-ground feedbacks are important in controlling ecosystem processes and properties. Plant species play a fundamental role in nutrient absorption, nutrient accumulation, nutrient distribution and nutrient return. Soil microorganisms are important in controlling plant nutrient availability and soil quality. Our main objective is to summarize the relationships between plants and microbes, such as facilitation and competition. Plants, as producers, provide nutrients for soil microorganisms via leaf litter and root exudation. Soil microorganisms, as decomposers, break down organic matter and provide nutrients to plants. A wide range of soil microbes form intimate symbiotic associations with plants, and this can stimulate plant productivity by delivering limited nutrients to their host plants. However, both plants and microbes compete for nutrients because plant nutrient uptake and microbial immobilization occur simultaneously. We provide an integrated analysis of effects of plant diversity on soil microbial diversity, as well as direct and indirect effects of soil microbes on plant diversity and productivity. Previously, the mechanisms of plants and microorganisms in regulating ecosystem nutrient cycling have been controversial. Litter chemical composition and diversity should be considered important functional traits that explain the mechanisms. It is clear that interactions between plants and microbes play a fundamental role in maintaining the stability of natural ecosystems. This review elucidates the linkage between aboveground and belowground processes, which have been treated separately in the past.

Key words: above- and below-ground, nutrient cycling, plant, soil microorganisms