Modeling canker incidence among ecoregions.

• Main Authors: Roger W. Ruess (10651781), Loretta M. Winton (10651784), Gerard C. Adams (10651787)
• Format: Still Image
• Language: unknown
• Published: 2021
• Subjects: Microbiology; Ecology; Infectious Diseases; Biological Sciences not elsewhere classified; smaller-diameter trees; Stand-level infection rates; growth declines; ecosystem function; aspen basal area; Widespread mortality; Tanana Kuskokwim ecoregion; Populus tremuloides; 88 study sites; novel canker disease; disturbance regimes; Widespread aspen mortality; landscape position; canker infection; United States; canker incidence; successional dynamics; Alaskan boreal forests; carbon starvation; modeling canker probability; Alaska Range; summer drought; canker pathogen; 6 Alaska ecoregions; Alaska paper birch; summer vapor pressure deficits; aspen leaf miner outbreak; alaska range; Kuskokwim; Alaska
• Online Access: https://doi.org/10.1371/journal.pone.0250078.g007

Probability of canker infection for different ecoregions as a function of DBH of an aspen tree (A), mean stand-level aspen DBH, a surrogate for stand age (B), and aspen basal area (C). Probabilities were calculated by fixing all other variables as mean values using the following equation derived from a mixed-effects logistic regression model incorporating site as a random effect: Logit (π) = log (π/(1- π)) = –0.761–0.177* DBH – 0.023* Relative Aspen Density + 0.092* Aspen Basal Area + 0.106* Mean Aspen DBH – 1.413* CK – 3.263* CR – 0.358* RM + 0.692* TKL – 0.736* NOM . Ecoregion β values are computed relative to YTU which does not appear in the model and has a log(odds) = the intercept when all other factors are 0. Contrasts derived from logistic models indicated the following differences in canker incidence among ecoregions; TKL a, YTU ab, RM bc, NOM abc, CK cd, CR d, where ecoregions with different letters are significantly different at P < 0.05. Ecoregion abbreviations follow Fig 4 .