Temporal Niche Modulates Species Interaction Under Thermal Fluctuations.

Global environmental change is reshaping thermal environments by increasing mean temperatures and altering diurnal temperature range (DTR) in complex, region-specific ways. Climate change, deforestation, and urbanization influence DTR with varying effects. How species with different daily temporal niches respond to such changes remains largely unexplored, particularly regarding interspecific interactions. We synthesize emerging evidence and develop a theoretical framework integrating thermal performance curves with temporal niche theory to address this critical knowledge gap. Our analysis shows that larger DTRs decrease the optimal mean temperatures for diurnal species, while increasing them for nocturnal species. Contrary to conventional views that temporal partitioning reduces competition, we show that DTR changes alter exploitative competition between temporally segregated species sharing common resources. This mechanism operates in diverse systems, from carrion competition between necrophagous insects to growth competition between plants with different photosynthetic pathways. Our framework provides mechanistic insights into how DTR changes affect biodiversity through altered competitive interactions and highlights the need to incorporate these dynamics into vulnerability assessments and conservation planning in the Anthropocene.