Global pattern of soil fauna drivel litter mixing incorporation to soil in relation to climate and litter quality

Earlier studies show that across all biomes about half of litter fall is consumed by soil fauna. Part of that litter can be incorporated in to mineral soil by process called bioturbation. Soil fauna bioturbation may affect various processes related to decomposition and stabilization of organic matter, soil water retention, formation of habitat for soil biota and so on. 

In this contribution I summarized global experiment aimed to estimate amount of litter which is incorporated in soil by soil fauna bioturbation.  To do so a I used a filed mesocosm experiment located in 23 locations in all major biomes of northern hemisphere from tundra to tropical rain forest.   Mesocosms containing litter and mineral soil in two separate compartments were exposed in soil litter interface. These mesocosm were either accessible to soil fauna or not which allow to measure removal of litter from soil surface as well as accumulation of litter in mineral soil as well as overall loss of litter from the mesocosm. Mesocosm were supplied in local litter. Overall fauna significantly increased carbon accumulation in mineral soil. The effect was higher in temperate and tropical climate and lover in cold and dry biomes. Amount of carbon incorporated by fauna into mineral soil significantly positively correlated with actual evapotranspiration and negatively with CN ratio of litter.  In comparison with previous studies of litter consumption it can be estimated that about half of litter consumed by soil fauna is incorporated in mineral soil.  To put this together it appears that in natural ecosystem about half of annual litter fall is consumed by soil fauna and half of that fauna incorporate into mineral soil. This makes soil fauna important player in global carbon cycle