Does Species Diversity Buffer Plant Populations Against Drought? (2025-05-02)

Abstract

Biodiversity loss and climate change are two anthropogenically driven environmental challenges impacting ecological and evolutionary outcomes. In Minnesota, the increasing prevalence of severe summer drought is a key sign of climate change, with implications for native plant survival and adaptation. Many studies have tested how drought influences plant traits like seed weight, germination, growth, and reproduction. However, few studies, if any, concurrently consider the effects of maternal species diversity on seed offspring phenotype and fitness. Plants adapt to their environment through phenotypic plasticity, which is partially influenced by changes in both gene expression and maternal environment effects. This study analyzes seeds of 11 native perennial prairie species from concurrent drought treatments (ambient rain vs. 43% rain-out) and diversity treatments (monoculture vs. 16-species mixes) at the University of Minnesota�s Cedar Creek Ecosystem Science Reserve. Seeds from these four treatments were weighed, sown in a common environment greenhouse, and measured for germination and morphological traits. RNA was extracted and sequenced from early plant tissue for one species, Andropogon gerardii, for a differential gene expression analysis. My results show significant plant response to the water availability and species diversity treatments, particularly at the earliest life history stages. The three major plant families included in the experiment showed unique and varying responses to the treatments. Gene expression results were consistent with the phenotypic response from Andropogon gerardii. Coupling common garden approaches with next-generation genomics is the most effective method to elucidate mechanisms of plant adaptation and to quantify the role of maternal environmental carryover on offspring phenotype.