Paleo Research in the Lab

Only a few of Konza prairie’s numerous (>550) vascular plant species have been closely studied. Predicted impacts of climate change on the tallgrass prairie region increase the importance of understanding how native tallgrass prairie species are likely to respond to future changes in water availability and air temperatures. Recognizing which traits are the best predictors of relative abundance in well-watered and water-stressed situations will aid in the prediction of plant community structure under altered temperature-precipitation regimes. Sally Tucker is conducting anatomical and physiological measurements taken on nearly 120 species of herbaceous tallgrass prairie plants grown from seed in a growth chamber. Gas exchange measurements are made under optimal light, temperature, and humidity conditions. All plants were exposed to a dry-down period and were monitored until stomatal conductance was zero. At this point, water potential (Ψ_crit) was measured and the plants were harvested to measure root length, diameter, volume, and mass, leaf area, leaf tissue density, root tissue density, and root to shoot ratio.

Using plant traits as indicators of drought tolerance in the Tallgrass Prairie
Only a few of Konza prairie’s numerous (>550) vascular plant species have been closely studied. Predicted impacts of climate change on the tallgrass prairie region increase the importance of understanding how native tallgrass prairie species are likely to respond to future changes in water availability and air temperatures. Recognizing which traits are the best predictors of relative abundance in well-watered and water-stressed situations will aid in the prediction of plant community structure under altered temperature-precipitation regimes. Sally Tucker is conducting anatomical and physiological measurements taken on nearly 120 species of herbaceous tallgrass prairie plants grown from seed in a growth chamber. Gas exchange measurements are made under optimal light, temperature, and humidity conditions. All plants were exposed to a dry-down period and were monitored until stomatal conductance was zero. At this point, water potential (Ψ_crit) was measured and the plants were harvested to measure root length, diameter, volume, and mass, leaf area, leaf tissue density, root tissue density, and root to shoot ratio.
	A small portion of species / individuals grown for trait comparison
	Results to date suggest clear trait differences exist between this large suite of grass and forb functional groups from tallgrass prairie. This suggests a dichotomy between dry-adapted plants with thin, dense leaves and roots, highly negative Ψ_crit, and large plant size and hydrophiles which have the opposite profile. A second axis offers more separation based on high photosynthetic rate, high conductance rate, and leaf posture, but fails to provide a distinction between C3 and C4 species. We are currently investigating the variability in stomatal characteristics within and among prairie populations. Preliminary data suggest that topoedaphic conditions affect stomatal density. This experiment will compare the density of site-grown leaves to leaves from plants re-sprouted in a standardized environment.
Prunella vulgaris, gas-exchange measurments, and an image used for root tissue density.