Study Reveals Microbial-litter Interactions Accelerate Litter Decomposition

Release Time:2020-08-25 Big Small

In terrestrial ecosystems, litter decomposition is carried out by a complex biotic community consisting of organisms that differ in size and function, such as microbial, microfauna and mesofauna. The ‘home-field advantage’ (HFA) describes the phenomenon where litter decomposition is accelerated in its home environment (i.e. in conspecific soil) due to a hypothesized specialized soil decomposer community-litter relationship. However, which parts of the soil decomposer community contribute to driving HFA is not fully understood.

 

A common way to manipulate the composition and function of the soil decomposer community is by using litter bags with varying mesh sizes to exclude different size-groups of soil biota, but this approach is difficult to distinguish the role of mesofauna and microflora in decomposition.

 

To address this issue, Dr. LI Yingbin and Dr. LI Qi from the Institute of Applied Ecology of the Chinese Academy of Sciences (CAS), together with researchers from Netherlands Institute of Ecology (NIOO-KNAW) carried out a litter transplant experiment in microcosms and inoculated sterilized soil with size fractionated soil communities to examine how size fractions of the soil biotic community affected litter decomposition and HFA effects.

 

The researchers found that the HFA effect increased with decreasing size fractions of the soil biotic community, demonstrated that soil microorganisms are specialized to decompose specific resources and thus promote HFA effects (Fig. 1, 2). This finding highlights the importance of microbial-litter interactions that have consequences for biogeochemical cycling.

 

This study entitled “‘Home’ and ‘away’ litter decomposition depends on the size fractions of the soil biotic community” has been published in Soil Biology and Biochemistry. 

 

The work was financially supported by the Netherlands Organisation for Scientific Research, the National Natural Science Foundation of China, and K. C. Wong Education Foundation.

Fig. 1 Principal component analysis (PCA) of the bacterial and fungal community composition based on the relative abundance of each OTU three months after inoculation of different size fractions of the soil biotic community extracted from J. vulgaris and T. vulgare soils. In each soil J. vulgaris and T. vulgare litter was decomposed (Image by LI Yingbin).

Fig. 2 Relationship between the home-field advantage index (HFA index) and community size fractions (6, 11, 20, 45, 850 μm) at two harvest times (three months and six months) (Image by LI Yingbin).