Litter quality and temperature modulate microbial diversity effects on decomposition in model experiments

Abstract

Abstract:The consequences of decline in biodiversity for ecosystem functioning is a major concern in soil ecology. Recent research efforts have been mostly focused on terrestrial plants, while, despite their importance in ecosystems, little is known about soil microbial communities. This work aims at investigating the effects of fungal and bacterial species richness on the dynamics of leaf litter decomposition. Synthetic microbial communities with species richness ranging from 1 to 64 were assembled in laboratory microcosms and used in three factorial experiments of decomposition. Thereafter, the functionality of the different microcosms was determined by measuring their capability to decompose materials with different chemical properties, including two species of litter (Quercus ilex L. and Hedera helix L.), cellulose strips and woody sticks. Incubation was done in microcosms at two temperatures (12°C and 24°C) for 120 days. The number of microbial species inoculated in the microcosms positively affected decomposition rates of Q. ilex and H. helix litters, while relationships found for cellulose and wood were not statistically significant. Diversity effect was greater at higher incubation temperature. We found lower variability of decay rates in microcosms with higher inoculated species richness of microbial communities. Our study pointed out that the relationships between inoculum microbial diversity and litter decomposition is dependent on temperature and litter quality. Therefore, the loss of microbial species may adversely affects ecosystem functionality under specific environmental conditions.

Disentangling the mixed effects of soil management on microbial diversity and soil functions: A case study in vineyards

“…In our study, we could not show a direct effect of soil microbial diversity on soil ecosystem functions such as litter decomposition. Since decomposition is a complex process, which involves interaction of different bacterial and fungal functional guilds 44 , it is assumed to be higher in soils with higher microbial richness 45 . However, evidence from field studies is largely lacking.…”

Structural and functional microbial diversity in deadwood respond to decomposition dynamics

“…Understanding the direction and extent of microbial interactions is of key importance for predicting the patterns of ecosystem processes under varying environmental pressures. Experiments on litter decomposition dynamics have shown that positive interactions may enhance leaf litter degradation (Bani et al, 2019) while competitive interactions among multi‐species microbial consortia were reported to negatively affect litter and wood decomposition (Boddy, 2000; Bonanomi et al, 2015; Cox et al, 2001). However, positive co‐occurrences may just reflect similar habitat requirements of the species involved with no effect on process rates and/or a lack of competitive exclusion (Odriozola et al, 2021).…”

The Influence of Plant Litter on Soil Water Repellency: Insight from 13C NMR Spectroscopy

“…The intrinsic initial biochemical characteristics of plant litter are major factors driving its decomposition rate [ 26 , 53 , 54 ], hence directly or indirectly affecting interconnecting ecological processes, including litter nutrient dynamics [ 55 – 57 ] and suitability for microbial feeding [ 58 – 60 ], phytotoxicity [ 29 , 61 ] and plant-soil negative feedback [ 27 ]. Surprisingly, few studies attempted to relate the biochemical characteristics of different organic products with their effect on SWR.…”