Soil functional responses to drought under range‐expanding and native plant communities

Abstract

Current climate warming enables plant species and soil organisms to expand their range to higher latitudes and altitudes. At the same time, climate change increases the incidence of extreme weather events such as drought. While it is expected that plants and soil organisms originating from the south are better able to cope with drought, little is known about the consequences of their range shifts on soil functioning under drought events.Here, we test how range‐expanding plant species and soil communities may influence soil functioning under drought. We performed a full‐factorial outdoor mesocosm experiment with plant communities of range expanders or related natives, with soil inocula from the novel or the original range, with or without summer drought. We measured litter decomposition, carbon mineralization and enzyme activities, substrate‐induced respiration and the relative abundance of soil saprophytic fungi immediately after drought and at 6 and 12 weeks after rewetting.Drought decreased all soil functions regardless of plant and soil origin except one; soil respiration was less reduced in soils of range‐expanding plant communities, suggesting stronger resistance to drought. After rewetting, soil functioning responses depended on plant and soil origin. Soils of native plant communities with a history of drought had more litter mass loss and higher relative abundance of saprophytic fungi than soils without drought and soils of range expanders. Functions of soil from range expanders recovered in a more conservative manner than soils of natives, as litter mass loss did not exceed the control rates. At the end of the experiment, after rewetting, most soil functions in mesocosms with drought history did not differ anymore from the control.We conclude that functional consequences of range‐expanding plants and soil biota may interact with effects of drought and that these effects are most prominent during the first weeks after rewetting of the soil. A free http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.13453/suppinfo can be found within the Supporting Information of this article.

Community‐level interactions between plants and soil biota during range expansion

“…Therefore, we suggest that although conditioning by unrelated and related range expanders explained low amount of variance in bacterial and fungal communities (Supporting Information S1 : Table S2), they can have an important role in plant growth. Indicator species analyses revealed that several taxa of fungal family Glomeraceae The mixture of original and new range soil communities, which simulates microbial range expansion (see also Manrubia, van der Putten, Weser, ten Hooven, et al, 2019) and allows co-evolved soil-borne enemies from the new range to catch up with range expanders and control their growth in their new range, did not have direct significant effect on plant community biomass in the present study. Interestingly, we found lower below-ground biomass of related range expanders in communities with unrelated range expanders than in communities with related range expanders in both original and new range soils but similar below-ground biomass of related range expanders in these plant communities in the presence of mixed soil communities.…”

Disentangling nematode and arbuscular mycorrhizal fungal community effect on the growth of range-expanding Centaurea stoebe in original and new range soil

“…Moreover, the origin of soil communities determined plant biomass production under drought, being in line with a recent meta-analyses, that suggests intensified plant-soil interactions under drought (Beals et al 2020). At the same time, a recent study has reported no differences in community-level biomass of range expanders between drought and ambient conditions (Manrubia et al 2019), which suggests that in communities, neighbouring plant species might reduce the intensity of plant-soil interactions during drought.…”

“…The possible role of soil organisms in the success of range-expanding plant species is well acknowledged (Engelkes et al 2008;van der Putten et al 2013;Dostálek et al 2016;van Nuland et al 2017). However, most of the available evidence suggesting the important role of soil organisms is obtained by 1) observational studies comparing the composition of soil organisms between ranges (Ramirez et al 2019;Wilschut et al 2019a), or by experimental studies that examine plant performance in response to complete soil communities (van Grunsven et al 2010;Manrubia et al 2019). Here we have taken a step further by studying the impacts of natural nematode and AMF communities, important groups of plant-associated organisms, from the original and new range on the growth of range-expanding C. stoebe in an experimental setting.…”

Climate change effects on plant-soil feedbacks and consequences for biodiversity and functioning of terrestrial ecosystems

“…These effects corresponded to the increased abundance of the so-called “drought response types” or “wet response types” among both bacteria and fungi ( 36 ). Furthermore, a recent outdoor mesocosm study ( 61 ) compared the current climatic situation with three future scenarios: range shifts of plants but not soil biota, range shifts of soil biota but not plants, and range shifts of both plants and soil biota. During the growing season, half of the mesocosms were exposed to drought, while the other half was provided with the 30-year average water conditions of nondrought years.…”