Substrate quality and not dominant plant community determines the vertical distribution and C assimilation of enchytraeids in peatlands

Abstract

1. Peatlands are important carbon (C) stores as a result of acidity, waterlogging conditions and low temperatures slowing decomposition rates. However, climate change is predicted to bring not only changes in abiotic conditions but also the replacement of peat-forming vegetation, such as Sphagnum mosses, with vascular plants. In these systems, enchytraeid worms represent the dominant mesofaunal group, and previous climate change manipulations have shown that their abundances and vertical distribution are strongly influenced by temperature and moisture gradients, with important implications for C cycling. Therefore, determining their behavioural responses to changes in both abiotic and biotic factors is crucial to quantify their contribution to decomposition processes.2. We investigated the importance of vertical edaphic gradients (soil moisture and labile C) on enchytraeids total numbers, vertical distribution and feeding activities by inverting intact soil cores and hence, reversing both substrate quality but leaving the microclimatic gradients intact. This manipulative experiment was set up in two different peatland areas, one dominated by heather (Erica mackaiana) and another by mosses (Sphagnum sp.) to determine the influence of different plant functional growth forms on these responses.3. Our results showed that most enchytraeid species were 'stayers' (i.e. in the 'Upturned cores', they remained in the same layer where they are 'Normally' located), and hence, their vertical distribution was more dependent on substrate quality than a change in microclimate. This response was more evident under drier conditions (i.e. the highest locations of the height gradient at the heather site) than at the wettest locations (i.e. the bottom of the slope and under mosses) due to more pronounced vertical gradients in substrate quality. Furthermore, radiocarbon measurements on enchytraeid tissues showed that to avoid competition among the growing populations for the limited labile resources present in the top layers, enchytraeids selected older C sources. 4. These findings indicate that future climate change scenarios will not only bring important changes in the abiotic conditions (temperature and moisture) and biotic properties of peatlands (both vegetation composition and below-ground soil biota | Additional supporting information may be found online in the Supporting Information section. How to cite this article: Briones MJI, Carrera N, Huang J, Barreal ME, Schmelz RM, Garnett MH. Substrate quality and not dominant plant community determines the vertical distribution and C assimilation of enchytraeids in peatlands.

Vegetative substrate configuration technology for tower foundation slope of transmission line in arid area considering species suitability

“…The vegetative substrate has strong drought resistance and cold resistance, and has a unique nutrient slow-release supply system. The vegetative substrate contains a variety of effective ingredients such as high-efficiency water retaining agent, binder, soil conditioner, biological bacterial fertilizer, slow-release agent, planting loam, etc., which can effectively resist drought and cold, and provide nutrients required for normal plant growth for a long time, [11][12] with high technical content and remarkable ecological effect. Traditional greening projects are often achieved by artificial planting or sowing under good environmental conditions.…”