Cellular Changes and Weather Variability in Encroaching Woody Plants

abstract:The tallgrass prairie in the Flint Hills of Kansas faces woody plant encroachment as one of several incessant threats. Many factors affect woody plant encroachment into prairies, and the effects of climatic variability, including temperature and precipitation, are among the most debated. Plants, in the long term, alter their physical structure and functional capacity to adapt to changes in external environmental conditions. These changes include changes to vascular tissue. We conducted a survey of three habitat types (prairie, a transitional woodland, and a forest edge) to identify the impacts of annual weather on woody plant cell physiology; specifically, lumen area, cell wall thickness, and cell diameter in both earlywood (produced during spring) and latewood (produced during summer). Intraspecific comparisons showed little difference among sites. However, there were differences in earlywood cell lumen area and overall cell diameter with precipitation among sites while latewood showed weak positive correlations. Cell wall thickness showed little or no correlation with precipitation in both earlywood and latewood. Temperature had no impact on our cellular metrics among all habitats, suggesting precipitation is the driving stressor in our species in this prairie setting.