@article {6303, title = {Plant responses to changing rainfall frequency and intensity}, journal = {Nature Reviews Earth \& Environment}, volume = {5}, year = {2024}, pages = {276{\textendash}294}, keywords = {LTER-KNZ}, url = {https://www.nature.com/articles/s43017-024-00534-0}, author = {Feldman, A.F. and Feng, X. and Felton, A.J. and Konings, A.G. and Knapp, A.K. and Biederman, A.J. and Poulter, B.} } @article {6001, title = {Precipitation{\textendash}productivity relationships and the duration of precipitation anomalies: An underappreciated dimension of climate change}, journal = {Global Change Biology}, volume = {27}, year = {2021}, pages = {1127 - 1140}, keywords = {LTER-KNZ}, issn = {1354-1013}, doi = {10.1111/gcb.15480}, url = {https://onlinelibrary.wiley.com/doi/10.1111/gcb.15480}, author = {Felton, A.J. and Alan K. Knapp and M. D. Smith} } @article {KNZ001928, title = {Carbon exchange responses of a mesic grassland to an extreme gradient of precipitation}, journal = {Oecologia}, year = {2018}, pages = {1 -12}, abstract = {

Growing evidence indicates that ecosystem processes may be differentially sensitive to dry versus wet years, and that current understanding of how precipitation affects ecosystem processes may not be predictive of responses to extremes. In an experiment within a mesic grassland, we addressed this uncertainty by assessing responses of two key carbon exchange processes\—aboveground net primary production (ANPP) and soil respiration (Rs) - to an extensive gradient of growing season precipitation. This gradient comprised 11 levels that specifically included extreme values in precipitation; defined as the 1st, 5th, 95th, and 99th percentiles of the 112-year climate record. Across treatments, our experimental precipitation gradient linearly increased soil moisture availability in the rooting zone (upper 20\ cm). Relative to ANPP under nominal precipitation amounts (defined as between the 15th and 85th percentiles), the magnitude of ANPP responses were greatest to extreme increases in precipitation, with an underlying linear response to both precipitation and soil moisture gradients. By contrast, Rs exhibited marginally greater responses to dry versus wet extremes, with a saturating relationship best explaining responses of Rs to both precipitation and soil moisture. Our findings indicate a linear relationship between ANPP and precipitation after incorporating responses to precipitation extremes in the ANPP\–precipitation relationship, yet in contrast saturating responses of Rs. As a result, current linear ANPP\–precipitation relationships (up to ~\ 1000\ mm) within mesic grasslands appear to hold as appropriate benchmarks for ecosystems models, yet such models should incorporate nonlinearities in responses of Rs amid increased frequencies and magnitudes of precipitation extremes.

}, keywords = {LTER-KNZ, Climate extremes, Drought, Primary production, Rainfall, soil respiration}, doi = {10.1007/s00442-018-4284-2}, url = {https://link.springer.com/article/10.1007/s00442-018-4284-2}, author = {Felton, A.J. and Alan K. Knapp and M.D. Smith} } @article {KNZ001887, title = {A reality check for climate change experiments: Do they reflect the real world?}, journal = {Ecology}, volume = {99}, year = {2018}, pages = {2145-2151}, abstract = {

Experiments are widely used in ecology, particularly for assessing global change impacts on ecosystem function. However, results from experiments often are inconsistent with observations made under natural conditions, suggesting the need for rigorous comparisons of experimental and observational studies. We conducted such a \“reality check\” for a grassland ecosystem by compiling results from nine independently conducted climate change experiments. Each experiment manipulated growing season precipitation (GSP) and measured responses in aboveground net primary production (ANPP). We compared results from experiments with long-term (33-yr) annual precipitation and ANPP records to ask if collectively (n\ =\ 44 experiment-years) experiments yielded estimates of ANPP, rain-use efficiency (RUE, grams per square meter ANPP per mm precipitation), and the relationship between GSP and ANPP comparable to observations. We found that mean ANPP and RUE from experiments did not deviate from observations. Experiments and observational data also yielded similar functional relationships between ANPP and GSP, but only within the range of historically observed GSP. Fewer experiments imposed extreme levels of GSP (outside the observed 33-yr record), but when these were included, they altered the GSP\–ANPP relationship. This result underscores the need for more experiments imposing extreme precipitation levels to resolve how forecast changes in climate regimes will affect ecosystem function in the future.

}, keywords = {LTER-KNZ}, doi = {10.1002/ecy.2474}, url = {https://esajournals.onlinelibrary.wiley.com/doi/epdf/10.1002/ecy.2474}, author = {Alan K. Knapp and Carroll, C.J.W. and Griffin-Nolan, R.J. and Slette, I.J. and Chavez, F.A. and Baur, L. and Felton, A.J. and Gray, J. and Hoffman, A.M. and Lemoine, N.P. and Mao, W. and Post, A. and M.D. Smith} }