Location: Forage and Livestock Production ResearchTitle: Differential responses of native and managed prairie pastures to environmental variability and management practices
|BAJGAIN, RAJEN - University Of Oklahoma|
|XIAO, XIANGMING - University Of Oklahoma|
|BASARA, JEFFREY - University Of Oklahoma|
|DOUGHTY, RUSSEL - University Of Oklahoma|
|WU, XIAOCUI - University Of Oklahoma|
|ZHOU, YUTING - Oklahoma State University|
|STEINER, JEAN - Retired ARS Employee|
Submitted to: Agricultural and Forest Meteorology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/2/2020
Publication Date: 8/19/2020
Citation: Bajgain, R., Xiao, X., Basara, J., Doughty, R., Wu, X., Wagle, P., Zhou, Y., Gowda, P.H., Steiner, J.L. 2020. Differential responses of native and managed prairie pastures to environmental variability and management practices. Agricultural and Forest Meteorology. 294. https://doi.org/10.1016/j.agrformet.2020.108137.
Interpretive Summary: This study compared the responses of co-located native tallgrass prairie pasture (NP) and managed pasture (MP – mainly dominated by old world blue stem) of Oklahoma to climate variability using 17 years (2000-2016) of gross primary productivity (GPP – total amount of carbon fixed by plants via photosynthesis). The study also considered the interactive effects of management factors and climate variability by identifying the critical climate windows (CCW) that influence annual variability in GPP. The GPP showed large inter-annual variability in MP than NP. Consequently, NP showed more resiliency under extreme climatic conditions. The range and timing of CCW affecting GPP were also different between NP and MP as MP was more responsive to spring temperature and fall rainfall. Results indicate that NP and MP should be treated differently while assessing the responses of pastures to climate variability.
Technical Abstract: Future climates in the US Southern Plains are expected to have larger variability in weather elements, especially rainfall. However, the degree and timing of climate variability that affect productivity of pasture managed differently have not been well studied. We examined the impacts of climate variability on grassland productivity using 17 years of gross primary productivity (GPP) for co-located native and managed pastures of Oklahoma. We also considered the interactive effects of management factors and climate variability by identifying the critical climate windows (CCW) that influence annual variability in GPP. Managed pasture (MP) showed greater variability of GPP than did native pasture (NP), particularly with reduced GPP in drought years. The resilience of native grasses under unfavorable climate extremes was evident by lower GPP anomalies in NP than MP during the 2011-2012 drought. Although both pastures experienced the same degree of climate variability, the CCW affecting GPP was significantly different between NP and MP due to the modulating impact of management practices on the responses of MP. Not only the range but also the timing of the CCW was different between NP and MP as MP was more responsive to the spring temperature and fall rainfall. Our findings warrant the incorporation of MP as a different commodity from NP when accounting for the ecosystem responses to climate variability in global climate models.