Managing resilience of forage crops to climate change through response diversity

- We propose a method to quantify yield stability through response diversity.
- Complementary responses of high latitude (60-66°) forage crop cultivars notably stabilize the yield.
- Principal component analysis (PCA) is a valuable tool in synthesizing the weather patterns critical to yield.

Diversity appears to be critical in enhancing the resilience of agriculture in the face of climate change and the increasing intensity and frequency of extreme weather events. However, every kind of diversity does not necessarily enhance resilience, but the diversity among responses is critical. Such response diversity reflects the ability to perform well under various conditions and the capacity within a single function to adapt to various changes. Here, we propose a method for quantifying response diversity to aid the management of resilience. We hypothesized that there is practically significant diversity in yield responses to the critical agro-climatic factors within the set of forage crop species and cultivars. Using data from multi-location forage crop cultivar trials (from 1980 to 2012), we quantified the response diversity in high-latitude (60-66°N) conditions to agro-climatic factors critical for the yield of the following species: Timothy (Phleum pratense L.), meadow fescue (Festuca pratensis Huds.), tall fescue (Lolium arundinaceum (Schreb)), Festulolium (Festuca sp. × Lolium sp.), red clover (Trifolium pratense L.) and Italian ryegrass (Lolium multiflorum L.). The agro-climatic factors determined to be the most critical explained 77% of the total yield variation. Ten clusters of cultivars best reflected the high response diversity occurring within the species. The magnitude of variation among the cultivars in dry matter yield response to the agro-climatic factors was 12-17% of the mean yield of all the cultivars. However, not all species showed response diversity to all critical weather conditions. We conclude that complementary responses of species and cultivars can practically significant enhance the performance of forage production under conditions of weather variability. Management options are also discussed.