Root litter decomposition is suppressed in species mixtures and in the presence of living roots

Plant species diversity and identity can significantly modify litter decomposition, but the underlying mechanisms remain elusive, particularly for root litter. Here, we aimed to disentangle the mechanisms by which plant species diversity alters root litter decomposition We hypothesised that 1) interactions between species in mixed communities result in litter that decomposes faster than litter produced in monocultures; 2) litter decomposition is accelerated in the presence of living plants, especially when the litter and living plant identities are matched (known as home field advantage).
Monocultures and a mixture of four common grassland species were established to obtain individual litter and a ‘natural’ root litter mixture. An ‘artificial’ mixed litter was created using litter from monocultures, mixed in the same proportions as the species composition in the natural litter mixtures based on qPCR measurements. These six root litter types were incubated in four monocultures, a four-sp...