Climate Change: A Driver of Variability in Phytopathogens

Abstract

Climate change is altering the environmental conditions that regulate phytopathogen survival, reproduction, dispersal, infection and interactions with host plants and vectors. This review examines climate change as a driver of variability in phytopathogens, with emphasis on changes in population dynamics, geographical distribution, genetic and phenotypic characteristics, virulence or aggressiveness, host range, adaptation and epidemiological traits. Temperature, precipitation, humidity, atmospheric CO₂ and extreme climatic events can modify pathogen performance and inoculum availability, but responses are strongly pathogen-specific and depend on host susceptibility, environmental context and pathogen thermal or ecological tolerances. Climate-driven redistribution and selection may alter the relative fitness of existing pathogen genotypes and phenotypes, creating opportunities for population differentiation, local adaptation and establishment in new geographical or ecological settings. These changes can also shift epidemic timing and duration, disease incidence and severity, inoculum production, dispersal, co-infection outcomes and vector-mediated transmission. Consequently, the reliability of host resistance, chemical control schedules, forecasting models and early-warning systems may change under future climatic conditions. Effective management will require climate-informed surveillance, regular validation of forecasting tools, genomic monitoring, durable resistance and integrated disease management adapted to local pathogen characteristics. Multidisciplinary integration of plant pathology, climatology, epidemiology, genomics and crop science is therefore important for anticipating emerging disease risks and supporting more adaptive and sustainable plant disease management under changing climates.