Between Dec 19, 2024 and Jan 2, 2025, datasets can be submitted to DRUM but will not be processed until after the break. Staff will not be available to answer email during this period, and will not be able to provide DOIs until after Jan 2. If you are in need of a DOI during this period, consider Dryad or OpenICPSR. Submission responses to the UDC may also be delayed during this time.

Browsing by Author "Whittington, Heather Renee"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Consequences of elevated temperature on prairie plants: legumes, nitrogen, and phenology.
    (2012-05) Whittington, Heather Renee
    Because prairies are often nitrogen (N) limited, prairie legumes can have significant impacts on the nitrogen (N) dynamics of these communities because of their ability to add fixed N to their surroundings through symbiotic biological N2-fixation and their N-rich tissues that can stimulate net nitrogen mineralization. Predicted increases in temperature have the potential to alter legume traits and functioning, which can feedback to affect ecosystem dynamics. The goal of this dissertation was to examine the effect of elevated temperature on the growth, phenology, and N nutrition of four prairie legumes: Amorpha canescens, Dalea purpurea, Lespedeza capitata, and Lupinus perennis, using both a growth chamber experiment and a manipulative field warming experiment. In the growth chamber experiment, seedlings of Lespedeza exhibited higher biomass and shoot N content at 28°C than 25°C, while Lupinus seedlings displayed decreased nodulation and lower shoot N concentration at the higher temperature. In the field warming study, Dalea and Lupinus displayed higher biomass under warming and all species exhibited lower shoot N concentrations under warming. Neither N2-fixation nor net N mineralization were affected by warming. Warming accelerated flowering for several species, including Amorpha and Dalea, and accelerated spring green-up, as evidenced by higher normalized difference vegetation index (NDVI) values in warmed communities in May. These results indicate that prairie legumes are responsive to increases in temperature in a species-specific manner and that warming may alter N-cycling by changing legume abundance and tissue N chemistry. Additionally, significant interannual variation in many variables and in their responses to warming emphasizes the need for long term studies to better understand and predict potential consequences of elevated temperature on plants and their ecosystems.