Long-term exposure to elevated CO ₂ enhances plant community stability by suppressing dominant plant species in a mixed-grass prairie

Abstract

Climate controls vegetation distribution across the globe, and some vegetation types are more vulnerable to climate change, whereas others are more resistant. Because resistance and resilience can influence ecosystem stability and determine how communities and ecosystems respond to climate change, we need to evaluate the potential for resistance as we predict future ecosystem function. In a mixed-grass prairie in the northern Great Plains, we used a large field experiment to test the effects of elevated CO 2 , warming, and summer irrigation on plant community structure and productivity, linking changes in both to stability in plant community composition and biomass production. We show that the independent effects of CO 2 and warming on community composition and productivity depend on interannual variation in precipitation and that the effects of elevated CO 2 are not limited to water saving because they differ from those of irrigation. We also show that production in this mixed-grass prairie ecosystem is not only relatively resistant to interannual variation in precipitation, but also rendered more stable under elevated CO 2 conditions. This increase in production stability is the result of altered community dominance patterns: Community evenness increases as dominant species decrease in biomass under elevated CO 2 . In many grasslands that serve as rangelands, the economic value of the ecosystem is largely dependent on plant community composition and the relative abundance of key forage species. Thus, our results have implications for how we manage native grasslands in the face of changing climate.climate change | elevated carbon dioxide | grassland | community stability | warming E cologists have long recognized the importance of climate in shaping plant communities across spatial and temporal scales (1). Together, precipitation and temperature characterize the distribution of terrestrial biomes across the globe. As climate changes, some biomes will be more vulnerable to temperature increase (2) or altered precipitation (3), whereas others will be more resistant (4-6). Ecological stability, the maintenance of community structure and function despite climatic fluctuation or disturbance (7-9), includes two components: resistance [lack of change despite perturbation (9)] and resilience [return to a previous state following a perturbation (10-13)]. Diversity (14) and productivity (11, 15) can both influence community stability (16) and dampen responses to environmental perturbation (5,9,17,18). What remains unclear is how stability and resistance respond to predicted changes in climate.Multiple climate change factors simultaneously impact plant performance, community structure, and productivity (4,19,20). For example, elevated CO 2 can improve water use efficiency and increase plant productivity (21-23), but warming can reduce it, counteracting the positive water-saving effects of elevated CO 2 (24). In addition, plant species and functional groups that differ in photosynthetic pathway often have contrasting respo...

Seasonality of soil moisture mediates responses of ecosystem phenology to elevated CO2 and warming in a semi‐arid grassland

“…; Zelikova et al . ), changes in allocation patterns from shoots to roots (Suter et al . ) and nitrogen limitation, can all suppress the stimulatory effects of elevated CO 2 (Luo et al .…”

Climatic change controls productivity variation in global grasslands

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Anthropogenic disturbance and rainfall variation threaten the stability of plant–ant interactions in the Brazilian Caatinga

“…Emer and collaborators (2013) showed that changes in the structure of interacting plant and animal communities are important for interaction network structure. Meanwhile, climate variation has been highlighted as an important factor shaping plant and animal communities across spatial and temporal scales (Zelicova et al 2014, Diamond et al 2016. Meanwhile, climate variation has been highlighted as an important factor shaping plant and animal communities across spatial and temporal scales (Zelicova et al 2014, Diamond et al 2016.…”

“…Meanwhile, climate variation has been highlighted as an important factor shaping plant and animal communities across spatial and temporal scales (Zelicova et al 2014, Diamond et al 2016. However, recent studies have proposed that plant and ant communities appear to be stable temporally even under climate change scenarios (Zelicova et al 2014, Donoso 2017. However, recent studies have proposed that plant and ant communities appear to be stable temporally even under climate change scenarios (Zelicova et al 2014, Donoso 2017.…”