Past research has demonstrated that multiple droughts can lead to accumulated hydraulic damages within plants, which has been a major contributor to large-scale quaking aspen die-off events in recent decades (Anderegg et al. 2013). This research project aims to better understand these compounded hydraulic changes resulting from repeated droughts and whether aspen are more susceptible to other stressors, particularly pathogen invasion, during or after a drought season. Over a two year-period, aspen propagules were raised in an experimental garden under four different treatment conditions: true-drought, recovering, once-treated, and control. In 2022, we measured drought stress responses throughout the growing season and took mortality surveys at the end of the season. We will now be quantifying and characterizing leaf microbiomes in each of the plants in an attempt to identify recognizable pathogens. We will then be analyzing whether water stress is potentially linked to increased pathogen vulnerability. This research will begin to answer larger questions about how plants allocate their resources under stress, and how compounded stressors can affect overall forest health year to year. Anderegg, W.R.L. et al. 2013. Drought's legacy: multiyear hydraulic deterioration underlies widespread aspen forest die-off and portends increased future risk. Global Change Bio. 19:1188-1196.