Deforestation is a major contributor to biodiversity loss, yet the impact of deforestation on daily microclimate variability and its implications for species with different daily activity patterns remain poorly understood. Using a recently developed microclimate model, we investigated the effects of deforestation on the daily temperature range (DTR) in low-elevation tropical areas and high-elevation temperate areas. Our results show that shade loss due to deforestation substantially increases DTR in these areas, suggesting a potential impact on species interactions. To test this hypothesis, we studied the competitive interactions between nocturnal burying beetles and all-day active blowfly maggots in forested and deforested habitats in Taiwan. We show that deforestation leads to increased DTR at higher elevations, which enhances the competitiveness of blowfly maggots during the day and leads to a higher failure rate of carcass burial by the beetles at night. Thus, deforestation-induced temperature variability not only modulates exploitative competition between species with different daily activity patterns but also likely exacerbates the negative impacts of climate change on nocturnal organisms. Our study highlights the need to protect forests, especially in areas where deforestation can greatly alter temperature variability, in order to prevent potential adverse effects on species interactions and their ecological functions.

All data can be opened using R.Funding provided by: Academia SinicaCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001869Award Number: AS-SS-106-05Funding provided by: Ministry of Science and Technology, TaiwanCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100004663Award Number: 100-2621-B-001-004-MY3Funding provided by: Ministry of Science and Technology, TaiwanCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100004663Award Number: 104-2311-B-001-028-MY3Funding provided by: Ministry of Science and Technology, TaiwanCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100004663Award Number: 108-2314-B-001-009-MY3Funding provided by: National Science FoundationCrossref Funder Registry ID: http://dx.doi.org/10.13039/100000001Award Number: IOS-1656098

All the datasets were collected during the field and lab studies "Higher temperature variability in deforested mountain regions impacts the competitive advantage of nocturnal species." In the study, we conducted field experiments in the forests and cultivated habitats along the elevational gradient in Mt. Hehuan in Taiwan. The experiments test the outcomes of the competition between burying beetles and blowflies by providing rat carcasses in the fields and recording whether the beetles can successfully secure (i.e., bury) the carcass. We also monitored the environmental temperature in each study site using an iButton datalogger. We also conducted lab experiments to measure the beetles' thermal performance and the blowflies' competitive ability in various thermal conditions.