Do invasive plants structure microbial communities to accelerate decomposition in intermountain grasslands?

Abstract

Invasive plants are often associated with greater productivity and soil nutrient availabilities, but whether invasive plants with dissimilar traits change decomposer communities and decomposition rates in consistent ways is little known. We compared decomposition rates and the fungal and bacterial communities associated with the litter of three problematic invaders in intermountain grasslands; cheatgrass (Bromus tectorum), spotted knapweed (Centaurea stoebe) and leafy spurge (Euphorbia esula), as well as the native bluebunch wheatgrass (Pseudoroegneria spicata). Shoot and root litter from each plant was placed in cheatgrass, spotted knapweed, and leafy spurge invasions as well as remnant native communities in a fully reciprocal design for 6 months to see whether decomposer communities were species‐specific, and whether litter decomposed fastest when placed in a community composed of its own species (referred to hereafter as home‐field advantage–HFA). Overall, litter from the two invasive forbs, spotted knapweed and leafy spurge, decomposed faster than the native and invasive grasses, regardless of the plant community of incubation. Thus, we found no evidence of HFA. T‐RFLP profiles indicated that both fungal and bacterial communities differed between roots and shoots and among plant species, and that fungal communities also differed among plant community types. Synthesis. These results show that litter from three common invaders to intermountain grasslands decomposes at different rates and cultures microbial communities that are species‐specific, widespread, and persistent through the dramatic shifts in plant communities associated with invasions.

Nitrogen deposition may increase litter accumulative CO2 release in a subtropical estuarine marsh

“…The downtrend in CO 2 evolution rates did not mean that microbes would die or activity decline in a short time (Li et al, 2015), and this was further confirmed by the PLFA data (Table 3). Previous studies suggested that the increasing easily-available matter (especially labile C) would accelerate the turnover of microorganisms (rstrategists, mainly bacteria) in the early phase, and later replaced by k-strategists (mainly fungi) due to growth-limiting substrate concentrations (Fontaine et al, 2003;Dilly et al, 2004;McTee et al, 2017), however, our bacteria and fungi biomass data did not show this trend during decomposition process.…”

Steering the soil microbiome by repeated litter addition

“…Our findings are in line with previous work showing that the addition of organic amendments in agricultural soils can affect fungal biomass and community compositions in soils (Clocchiatti et al, 2020;Moll et al, 2015;Reardon & Wuest, 2016) and that leaf litters (Asplund et al, 2018;Keiser et al, 2011;Lin et al, 2019;Veen, Snoek, et al, 2019) and decomposing wood (Purahong et al, 2019) are associated with unique microbiomes on their surface. We now progress on this understanding and show that repeated additions of a certain organic input can result in the development of litter-specific soil fungal communities (Fanin et al, 2014;McTee et al, 2017). In our approach we used sterilised litter in order to prevent the introduction of 'home' decomposers from the phyllosphere with the litter itself and focused on how interactions between soil and litter type affected litter mass loss and the microbes present in the soil.…”

Litter decomposition affected by bamboo expansion is modulated by litter‐mixing and microbial composition

“…climate change, land use change disturbance; Landhäusser et al., 2010) undoubtedly alter ecosystem processes and function, including soil microbial community structure (Kourtev et al., 2002; Stefanowicz et al., 2016) and soil C and nutrient cycling associated with litter decomposition (Ashton et al., 2005; Liao et al., 2008). However, the linkage between microbial community structure and litter decomposition in the context of plant community change is still less understood (Arthur et al., 2012; Kourtev et al., 2002; McTee et al., 2017). Emerging evidences show that microbial community structure may adapt to nutrient condition/limitation, for example, nitrogen (N) and phosphorous (P), to control the litter decomposition (Hoyos‐Santillan et al., 2018; Kaiser et al., 2014), which hints a feedback between decomposition and microbial composition when plant community changes, but field evidence remains lacking.…”