Drought soil legacy alters drivers of plant diversity-productivity relationships in oldfield systems

Abstract

Ecosystem functions are threatened by both recurrent droughts and declines in biodiversity at a global scale, but the drought dependency of diversity-productivity relationships remains poorly understood. Here, we use a two-phase mesocosm experiment with simulated drought and model oldfield communities (360 experimental mesocosms/plant communities) to examine drought-induced changes in soil microbial communities along a plant species richness gradient and to assess interactions between past drought (soil legacies) and subsequent drought on plant diversity-productivity relationships. We show that (i) drought decreases bacterial and fungal richness and modifies relationships between plant species richness and microbial groups; (ii) drought soil legacy increases net biodiversity effects, but responses of net biodiversity effects to plant species richness are unaffected; and (iii) linkages between plant species richness and complementarity/selection effects vary depending on past and subsequent drought. These results provide mechanistic insight into biodiversity-productivity relationships in a changing environment, with implications for the stability of ecosystem function under climate change.

Biodiversity and Ecosystem Function under Simulated Gradient Warming and Grazing

“…Furthermore, our study found that for vegetation on the Tibetan Plateau, a temperature increase of approximately 1 °C is the threshold limit for vegetation to survive well, and that the direct factor affecting the survival of alpine vegetation is soil moisture content. This result is consistent with the majority of studies showing that biodiversity loss is closely linked to drought [ 40 , 41 , 42 ]. Grazing reduces the number of plant species and alters the competitive relationships of species in the community, as shown in previous studies where grazing reduced the amount and height of taller grasses and shorter weeds had more ecological niches to grow [ 43 , 44 , 45 , 46 ].…”

“…are closely related to climate change and anthropogenic grazing activities. The combined effects of this are still underexplored [ 40 ]. Our study analyzed the effects of simulated gradient warming and grazing on the relationship between plant diversity and productivity and community stability, which resulted in three key findings: (1) Plant biodiversity, soil microbial diversity and community productivity in alpine grasslands show fluctuating trends with temperature gradients, and a temperature increase below approximately 1 °C is beneficial to alpine grasslands; moderate grazing only increases the fungal diversity of the soil surface layer.…”

Drought legacies and ecosystem responses to subsequent drought

“…Drought can alter species composition and generally tends to decrease the abundance and the richness of soil fauna (Coyle et al, 2017;DeVries et al, 2012;Lindberg et al, 2002;Lindberg & Bengtsson, 2006). It has recently been shown to also cause legacies in the microbial community composition (Canarini et al, 2021;Evans et al, 2022;Kaisermann et al, 2017;Liu et al, 2022;Meisner et al, 2018Meisner et al, , 2021Xi et al, 2022). Drought was observed to promote fungi and to reduce bacteria (Fuchslueger et al, 2014;Preece et al, 2019) and bacterial networks (DeVries et al, 2018).…”

Plant community diversity alters the response of ecosystem multifunctionality to multiple global change factors

“…However, whether changes in complementarity and/or selection effects mediate the impact of global change factors on ecosystem multifunctionality has not been tested. Furthermore, complementarity and selection effects are in uenced by global change factors 24,25 , but the underlying mechanisms remain unclear. On the one hand, global change factors might strengthen complementarity effects and ecosystem multifunctionality by providing novel niches, increased niche width, and decreased niche overlap 26,27,28 (Fig.…”