A reality check for climate change experiments: Do they reflect the real world?

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 stu...

Full description

Saved in:
Bibliographic Details
Published in:Ecology (Durham) 2018-10, Vol.99 (10), p.2145-2151
Main Authors: Knapp, Alan K., Carroll, Charles J.W., Griffin-Nolan, 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.
Format: Article
Language:English
Subjects:
aboveground net primary production
Annual precipitation
Climate change
Ecological monitoring
Ecosystem assessment
Ecosystems
Environmental changes
Experiments
extreme climate
field experiments
Grasslands
Historical account
long‐term data
Precipitation
Primary production
Rainfall
Weather forecasting
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
ISSN:0012-9658
1939-9170
DOI:10.1002/ecy.2474