Linking advanced spring phenology with growing season plant water stress.
Abstract
The timing of spring leaf emergence in deciduous forests ecosystems exerts strong control over annual water and carbon budgets. Characterizing the relationship between phenology and annual water budgets is therefore a powerful tool to understand the dynamics of seasonal water availability and plant water stress. In years with fewer precipitation inputs, early onset of spring may increase the likelihood of summer water stress due to increased transpiration and subsequent draining of soil water reserves. Here, we use observations from the Morgan-Monroe State Forest eddy-covariance flux tower and co-located leaf-area index observations, to investigate the relationship of spring leaf emergence and growing season water budgets. We used the ratio of evapotranspiration to potential evapotranspiration (ET/PET) to determine spring water budgets and soil water content (SWC) to determine summer water stress. We find that the earlier start to a season (i.e. leaf emergence) results in a higher ratio of spring ET/PET and lower summer SWC suggesting that earlier spring onset can increase the likelihood, or further exacerbate, plant water stress later in the growing season. We aim to extend this study to other sites classified as deciduous broadleaf forests in the eastern US, which may support the use of early spring leaf emergence as an indicator of potential summer water stress.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMB088...06D
- Keywords:
-
- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0416 Biogeophysics;
- BIOGEOSCIENCES;
- 0426 Biosphere/atmosphere interactions;
- BIOGEOSCIENCES;
- 0476 Plant ecology;
- BIOGEOSCIENCES