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A reality check for climate change experiments: Do they reflect the real world?
Author(s) -
Knapp Alan K.,
Carroll Charles J.W.,
GriffinNolan Robert J.,
Slette Ingrid J.,
Chaves Francis A.,
Baur Lauren E.,
Felton Andrew J.,
Gray Jesse E.,
Hoffman Ava M.,
Lemoine Nathan P.,
Mao Wei,
Post Alison K.,
Smith Melinda D.
Publication year - 2018
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.1002/ecy.2474
Subject(s) - primary production , precipitation , ecosystem , environmental science , climate change , ecology , grassland ecosystem , grassland , range (aeronautics) , functional ecology , atmospheric sciences , climatology , geography , biology , meteorology , materials science , geology , composite material
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.