@article {KNZ001746, title = {Beyond arctic and alpine: the influence of winter climate on temperate ecosystems}, journal = {Ecology}, volume = {97}, year = {2016}, pages = {372 - 382}, abstract = {

Winter climate is expected to change under future climate scenarios, yet the majority of winter ecology research is focused in cold-climate ecosystems. In many temperate systems, it is unclear how winter climate relates to biotic responses during the growing season. The objective of this study was to examine how winter weather relates to plant and animal communities in a variety of terrestrial ecosystems ranging from warm deserts to alpine tundra. Specifically, we examined the association between winter weather and plant phenology, plant species richness, consumer abundance, and consumer richness in 11 terrestrial ecosystems associated with the U.S. Long-Term Ecological Research (LTER) Network. To varying degrees, winter precipitation and temperature were correlated with all biotic response variables. Bud break was tightly aligned with end of winter temperatures. For half the sites, winter weather was a better predictor of plant species richness than growing season weather. Warmer winters were correlated with lower consumer abundances in both temperate and alpine systems. Our findings suggest winter weather may have a strong influence on biotic activity during the growing season and should be considered in future studies investigating the effects of climate change on both alpine and temperate systems.

}, keywords = {LTER-KNZ}, doi = {10.1890/15-0153.1}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/15-0153.1}, author = {L. Ladwig and Z. Ratajczak and Ocheltree, T.W. and Hafich, K.A. and Churchill, A.C. and Frey, S.J.K. and Fuss, C.B. and Kazanski, C.E. and Mu{\~n}oz, J.D. and Petrie, M.D. and Reinmann, A.B. and Smith, J.G.} } @article {KNZ001709, title = {The sensitivity of carbon exchanges in Great Plains grasslands to precipitation variability}, journal = {Journal of Geophysical Research: Biogeosciences}, volume = {121}, year = {2016}, pages = {280-294}, abstract = {

In the Great Plains, grassland carbon dynamics differ across broad gradients of precipitation and temperature, yet finer-scale variation in these variables may also affect grassland processes. Despite the importance of grasslands, there is little information on how fine-scale relationships compare between them regionally. We compared grassland C exchanges, energy partitioning and precipitation variability in eight sites in the eastern and western Great Plains using eddy covariance and meteorological data. During our study, both eastern and western grasslands varied between an average net carbon sink and a net source. Eastern grasslands had a moderate vapor pressure deficit (VPD = 0.95 kPa) and high growing season gross primary productivity (GPP = 1010 \± 218 g C m\−2 m\−2 y\−1). Western grasslands had a growing season with higher VPD (1.43 kPa) and lower GPP (360 \± 127 g C m\−2 m\−2 y\−1). Western grasslands were sensitive to precipitation at daily timescales, whereas eastern grasslands were sensitive at monthly and seasonal timescales. Our results support the expectation that C exchanges in these grasslands differ as a result of varying precipitation regimes. Because eastern grasslands are less influenced by short-term variability in rainfall than western grasslands, the effects of precipitation change are likely to be more predictable in eastern grasslands because the timescales of variability that must be resolved are relatively longer. We postulate increasing regional heterogeneity in grassland C exchanges in the Great Plains in coming decades.

}, keywords = {LTER-KNZ}, doi = {10.1002/2015JG003205}, url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015JG003205}, author = {Petrie, M.D. and N. Brunsell and Vargas, R. and Scott. L. Collins and Flanagan, L.B. and Hanan, N.P. and Litvak, M.E. and Suyker, A.E.} } @article {KNZ001440, title = {Climate change alters growing season flux dynamics in mesic grasslands}, journal = {Theoretical and Applied Climatology}, volume = {107}, year = {2012}, pages = {427 -440}, abstract = {

Changing climate could affect the functioning of grassland ecosystems through variation in climate forcings and by altering the interactions of forcings with ecological processes. Both the short and long-term effects of changing forcings and ecosystem interactions are a critical part of future impacts to ecosystem ecology and hydrology. To explore these interactions and identify possible characteristics of climate change impacts to mesic grasslands, we employ a low-dimensional modeling framework to assess the IPCC A1B scenario projections for the Central Plains of the United States; forcings include increased precipitation variability, increased potential evaporation, and earlier growing season onset. These forcings are also evaluated by simulations of vegetation photosynthetic capacity to explore the seasonal characteristics of the vegetation carbon assimilation response for species at the Konza Prairie in North Central Kansas, USA. The climate change simulations show decreases in mean annual soil moisture and and carbon assimilation and increased variation in water and carbon fluxes during the growing season. Simulations of the vegetation response show increased variation at the species-level instead of at a larger class scale, with important heterogeneity in how individual species respond to climate forcings. Understanding the drivers and relationships behind these ecosystem responses is important for understanding the likely scale of climate change impacts and for exploring the mechanisms shaping growing season dynamics in grassland ecosystems.

}, keywords = {LTER-KNZ, ecohydrology, Konza Prairie, Low-dimensional modeling, Nonlinear interactions, Soil moisture feedback}, doi = {10.1007/s00704-011-0484-y}, url = {https://link.springer.com/article/10.1007\%2Fs00704-011-0484-y}, author = {Petrie, M.D. and N. Brunsell and Jesse B. Nippert} } @article {KNZ001396, title = {The role of precipitation variability on the ecohydrology of grasslands}, journal = {Ecohydrology}, volume = {5}, year = {2012}, pages = {337 -345}, abstract = {

Precipitation event timing and magnitude are important drivers of ecosystem processes and are instrumental in creating landscape heterogeneity. Ecosystems respond to precipitation and other driving variables at different spatial and temporal scales, which complicates understanding of the relationships that govern ecosystem conditions. To better characterize the ecosystem response, we present a low-dimensional framework for simulating the influence of precipitation event timing and magnitude on grassland ecosystems, with particular focus on characterizing the temporal sensitivity of water and carbon fluxes to climate forcings and the feedback of water and carbon on soil moisture availability. Results show variation in daily through seasonal sensitivity of ecosystem water and carbon fluxes and identifies the way these sensitivities change at daily to annual timescales to shape long-term ecosystem states. This provides for a better understanding of the nonlinearities inherent to ecosystem interactions during the growing season and provides assessment of the extent that precipitation variance has on grassland functioning and heterogeneity. Copyright \© 2011 John Wiley \& Sons, Ltd.

}, keywords = {LTER-KNZ}, doi = {10.1002/eco.224}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/eco.224}, author = {Petrie, M.D. and N. Brunsell} }