Relationships Between Leaf Stomatal Properties and Whole-Tree Water Use in a Bottomland Hardwood EcosystemThe collection of physiological response data from trees can be a challenging and time-consuming task particularly in ecosystems with high species diversity. Leaf stomatal properties are more easily obtained and may inform forest water use and productivity models if they exhibit enough correlation with physiological functioning. Forestry major Justin Yow compared stomatal properties across various tree species from three plant families growing in a bottomland forest to determine if stomatal properties correlate with physiological functioning. Sapflow was measured in seven hardwood species (American elm, winged elm, shagbark hickory, willow oak, water oak, cherrybark oak and swamp chestnut oak) using heat dissipation sensors. Vapor pressure deficit (VPD), soil moisture, and photosynthetically active radiation (PAR) were monitored simultaneously. Seasonal water use per unit leaf area and relationships between daily water use and environmental parameters were estimated to determine the response of sapflow to environmental drivers. Leaves were collected from tree canopies at the end of the growing season. Epidermal peels were made and analyzed to quantify stomatal density and length.
Among species, stomatal density varied significantly, with American elm having a significantly lower density than all the oaks. Shagbark hickory also had a significantly lower stomatal density than all oak species except water oak. Across all tree species, stomatal density had a significantly negative correlation with seasonal water use per unit leaf area and daily sapflow responses to VPD and PAR. These results show that in an area of rich tree species diversity density measurements tended to be similar within tree families but significantly different across families. Based on these findings, stomatal parameters may be used to predict seasonal water use per unit leaf area and responses of water use to environmental parameters across tree species to increase understanding of relationships between leaf structure and physiological functioning.
News / Recognition
Undergraduate Research Symposium
Katherine Abell, a wildlife, fisheries, and aquaculture major, and Zachary Senneff, a forestry major, were among the winners of the 2014 MSU Undergraduate Research Symposium. Abell placed first in the community engagement and social sciences categories and Senneff placed second in the biological sciences and engineering category.