Nonlinear shifts in infectious rust disease due to climate change

Abstract

Range shifts of infectious plant disease are expected under climate change. As plant diseases move, emergent abiotic-biotic interactions are predicted to modify their distributions, leading to unexpected changes in disease risk. Evidence of these complex range shifts due to climate change, however, remains largely speculative. Here, we combine a long-term study of the infectious tree disease, white pine blister rust, with a six-year field assessment of drought-disease interactions in the southern Sierra Nevada. We find that climate change between 1996 and 2016 moved the climate optimum of the disease into higher elevations. The nonlinear climate change-disease relationship contributed to an estimated 5.5 (4.4–6.6) percentage points (p.p.) decline in disease prevalence in arid regions and an estimated 6.8 (5.8–7.9) p.p. increase in colder regions. Though climate change likely expanded the suitable area for blister rust by 777.9 (1.0–1392.9) km2 into previously inhospitable regions, the combination of host-pathogen and drought-disease interactions contributed to a substantial decrease (32.79%) in mean disease prevalence between surveys. Specifically, declining alternate host abundance suppressed infection probabilities at high elevations, even as climatic conditions became more suitable. Further, drought-disease interactions varied in strength and direction across an aridity gradient—likely decreasing infection risk at low elevations while simultaneously increasing infection risk at high elevations. These results highlight the critical role of aridity in modifying host-pathogen-drought interactions. Variation in aridity across topographic gradients can strongly mediate plant disease range shifts in response to climate change.

Elevating Air Temperature May Enhance Future Epidemic Risk of the Plant Pathogen Phytophthora infestans

“…In this study, we first investigated the patterns and mechanisms of thermal adaptation in pathogen populations and then proceeded to infer how pathogens may adapt to global warming by comparing the functional changes experienced by pathogens with different thermal adaptation histories under a series of experimental temperatures. The local adaptation of pathogen aggressiveness to air temperature is supported by the observed significant difference in AUDPC among P. infestans populations sampled from different locations ( Table 1 ), consistent with previous reports on the thermal adaptation of the metabolic rates and other traits of many species [ 34 , 75 , 76 ], including pathogens [ 8 , 77 , 78 ]. The higher genetic differentiation in aggressiveness compared to SSR markers suggests that the observed difference is caused by diversifying selection [ 41 , 79 , 80 ], and local air temperature might be one of the selection agents, as indicated by the strong association between the thermal biology of the pathogen and the annual mean temperature at its collection site ( Figure 2 ).…”

Interaction of drought‐ and pathogen‐induced mortality in Norway spruce and Scots pine

“…However, we recognize that pathogen-drought interactions are complex and multidimensional. Drought can have simultaneous, non-linear impacts on both host and pathogen populations (Dudney et al, 2021), and therefore, integrative research including all these impacts is needed to improve mechanistic tree mortality modelling.…”

Impact of Climate Change on Dryland Agricultural Systems: A Review of Current Status, Potentials, and Further Work Need

“…6 Interactive effect of elevated CO 2 , temperature, and drought on soil organic carbon the globe. However, this will vary from place to place as drier climate might have low disease and insect occurrence in future (Dudney et al, 2021). Thus researchers suggested application of integrated pest management approaches such as frequent pest scouting, disease forecasting and predictive modeling to combat climate change induced biotic stresses.…”