Plant diversity improves resistance of plant biomass and soil microbial communities to drought

Abstract

1. Biodiversity is known to affect ecosystem resistance and have implications for the maintenance of ecosystem functions and services under climate change.Compared to numbers of studies focusing on above-ground vegetation, the response of below-ground communities to abiotic stresses along plant diversity gradients is often ignored and is considered an important knowledge gap in ecosystem ecology. Here we conducted an integrative research to evaluate the resistance of plant biomass, and soil microbial communities and associated functional profiles to drought under varying plant diversity.2. We carried out a 3-year manipulation experiment by factorially controlling plant diversity gradient (1, 2, 4 and 8 species richness) and soil moisture treatment (drought and non-drought), and investigated the responses of plant biomass, soil bacterial and fungal diversity and community composition, soil glomalin, and five key soil enzymes.3. We found that plant diversity significantly improved the resistance of soil fungal communities and microbial functional profiles characterized by soil glomalin and five key enzymes, which was partly driven by the availability and accessibility of soil resources (e.g. soil moisture and organic matter) mediated by plant diversity. Furthermore, our results indicated that the enhanced resistance of fungal communities was consistent with ecological insurance theory that diverse fungal communities at high plant diversity had a higher probability of containing taxa that adapt to drought. Synthesis.Our study provides novel empirical insights into the mechanism underlying the regulatory effect of plant diversity on resistance of above-ground vegetation and below-ground biota to drought, with implications for understanding ecosystem response to climate change and improving biodiversity conservation practices. K E Y W O R D Sabove-ground and below-ground linkages, biodiversity, complementarity and selection effects, drought, global change ecology, physiological traits, resistance, soil enzyme activities | 1657

Different and unified responses of soil bacterial and fungal community composition and predicted functional potential to 3 years’ drought stress in a semiarid alpine grassland

“…Changes in fungal community diversity result from fungal redistribution, water use ( Barnard et al, 2013 ), or mycelial contraction ( Hossain et al, 2007 ), leading the community to adopt ecological strategies appropriate to different drought conditions. Our study found that BGB significantly affected fungal diversity ( Figure 4 ), which is consistent with the results of previous studies ( Li et al, 2022b ). This result may be attributed to two aspects.…”

Positive plant diversity effects on soil microbial drought resistance are linked to variation in labile carbon and microbial community structure

“…Plant diversity has been shown to impact soil physicochemical properties and the soil microbial community via differences in root biomass, the quantity and quality of rhizodeposits and litter inputs, as well as changes in plant nutrient uptake and water use (Eisenhauer et al, 2017;El Moujahid et al, 2017;Orwin & Wardle, 2005). In line with expectations, we found that plant diversity had a significant effect on most of the biotic and abiotic soil variables that were recorded under ambient conditions; the only exceptions were total Li et al, 2022). Tighter linkages between fungi and plant roots and the extension of fungal mycelia from roots into soil may explain the results obtained here for fungal and bacterial Shannon diversity metrics (Yang et al, 2017).…”

“…Although positive effects of plant diversity have previously been reported for some attributes of microbial performance under drought (e.g. cell counts, hyphal length, AMF infection rates, Bennett et al, 2020), as well as for microbial community structure (Li et al, 2022), other grassland studies of ‘diversity × drought’ interactions on microbial biomass have generated mixed results (Thakur et al, 2015). Divergent results among studies likely reflect variation in drought treatments and soil properties across the different experiments, as well as variable responses of root exudation to drought (Preece & Peñuelas, 2016); abiotic soil properties such as pH, C, nutrient availability and/or stoichiometry have the potential to mediate microbial responses to environmental change, either by shaping the intrinsic attributes of soil microbial communities that confer resistance or by buffering the impact of the environmental disturbance itself on the soil microbial community (Bardgett & Caruso, 2020; Griffiths & Philippot, 2013).…”

“…The positive relationship observed between microbial resistance to drought and fungal diversity is consistent with the ecological insurance hypothesis, that is, that high diversity insures against declines in ecosystem function (Yachi & Loreau, 1999). Unlike insurance effects of plant diversity on ecosystem function, studies documenting insurance effects of microbial diversity on microbial processes in relation to environmental fluctuations are extremely limited (Awasthi et al, 2014; Li et al, 2022). It is nevertheless reasonable to expect that diverse microbial communities are more likely to contain species that are resistant to drought, as well as hosting a greater proportion of functionally redundant species which can also enhance community stability (Griffiths & Philippot, 2013).…”

Nitrogen Deposition Drives Response and Recovery in the Context of Precipitation Change and Its Reversal in an Arid Ecosystem

“…Thus, a low drought resistance could be observed in response to elevated N deposition, suggesting that ecosystem responses to precipitation changes may be related to N levels. Moreover, plant diversity in a grassland ecosystem can enhance the resistance of plant biomass and soil microbial communities to drought (Li et al., 2022), implying that both plant and soil microbial communities might be involved in responses to precipitation changes under conditions of N enrichment (Li et al., 2022; Ochoa‐Hueso, 2016; Valliere et al., 2017).…”