Assessing the climate resilience of cropping systems through response diversity
Kaseva, Janne (2023-02-24)
Väitöskirja
24.02.2023
Lappeenranta-Lahti University of Technology LUT
Acta Universitatis Lappeenrantaensis
School of Energy Systems
School of Energy Systems, Ympäristötekniikka
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Julkaisun pysyvä osoite on
https://urn.fi/URN:ISBN:978-952-335-921-5
https://urn.fi/URN:ISBN:978-952-335-921-5
Tiivistelmä
Northern agriculture faces a rapidly changing climate with increased weather variability. Diversification can reduce the sensitivity of crops to disturbances and foster their capacity to adapt and transform. Increased climate resilience of yields can provide a buffer against climate-related uncertainty and variability. Therefore, it is a key aspect in managing the resilience of the food system, which is increasingly facing fluctuations. Response diversity also enables the evaluation and comparison of the development of diversity in regions over time. This dissertation presents a novel approach to quantifying the diversity of yield responses to weather and outlines its benefits over mere richness of cultivars or crop species. Further, the impact of land-use diversification on economic efficiency is evaluated.
Long-term weather data and yield data for barley and forage crop cultivars were gathered from Finnish regions, and those for wheat were gathered from eight other European countries besides Finland for the period 1980–2014. In addition, Finnish profitability bookkeeping data for land use and economy was utilised. Clustering was based initially on Mahalanobis distances and, later, on principal component scores obtained as a byproduct of grouping the agro-climatic variables based on the yield responses. To identify the development in response diversity, the diversity of the clusters cultivated was determined regionally and annually. The most methodologically justified choices were the use of principal component analysis to obtain a more interpretable and meaningful clustering and the use of the exponential of the Shannon index as a measure of true diversity.
Despite ongoing increases in the cultivar diversity of Finnish barley, the diversity in the yield responses to weather conditions decreased in the important regions for cultivation. The yield responses among new cultivars showed greater homogeneity than those among older cultivars. Moreover, in European farmers’ fields, a declining diversity of responses to weather patterns relevant to wheat yield was found. This diversity started to decline in the 2000s, with the decline being the strongest in Czechia. Conversely, the development in response diversity was the most positive in Slovakia. The response diversity of forage crop cultivars clearly depended on the soil type. Unlike clay or organic soils, coarse mineral soils had a reduced response diversity of species and cultivars, indicating a relatively weaker ability to successfully cope with uncertain climate change.
The proposed approach to empirically identify response diversity in order to manage resilience and adaptive capacity enables added value by guiding tailored diversification that allows actors in the food chain to prepare for unexpected fluctuations and changes that are currently very relevant in Europe, thereby securing economic efficiency as well.
Long-term weather data and yield data for barley and forage crop cultivars were gathered from Finnish regions, and those for wheat were gathered from eight other European countries besides Finland for the period 1980–2014. In addition, Finnish profitability bookkeeping data for land use and economy was utilised. Clustering was based initially on Mahalanobis distances and, later, on principal component scores obtained as a byproduct of grouping the agro-climatic variables based on the yield responses. To identify the development in response diversity, the diversity of the clusters cultivated was determined regionally and annually. The most methodologically justified choices were the use of principal component analysis to obtain a more interpretable and meaningful clustering and the use of the exponential of the Shannon index as a measure of true diversity.
Despite ongoing increases in the cultivar diversity of Finnish barley, the diversity in the yield responses to weather conditions decreased in the important regions for cultivation. The yield responses among new cultivars showed greater homogeneity than those among older cultivars. Moreover, in European farmers’ fields, a declining diversity of responses to weather patterns relevant to wheat yield was found. This diversity started to decline in the 2000s, with the decline being the strongest in Czechia. Conversely, the development in response diversity was the most positive in Slovakia. The response diversity of forage crop cultivars clearly depended on the soil type. Unlike clay or organic soils, coarse mineral soils had a reduced response diversity of species and cultivars, indicating a relatively weaker ability to successfully cope with uncertain climate change.
The proposed approach to empirically identify response diversity in order to manage resilience and adaptive capacity enables added value by guiding tailored diversification that allows actors in the food chain to prepare for unexpected fluctuations and changes that are currently very relevant in Europe, thereby securing economic efficiency as well.
Kokoelmat
- Väitöskirjat [979]