Mid-Term Impact of Climate Change on Hazelnut Yield

Abstract

The impacts of climate change on hazelnut production in Turkey—the world’s largest producer and exporter—may significantly affect the global hazelnut market depending on production and yield change. In this paper, based on gridded climate data with a 10-km horizontal resolution from regional climate model RegCM4.4 under the RCP8.5 business-as-usual scenario, multiple regression analysis was conducted to investigate yield change for the period of 2021–2050. We examined a total of 88 different locations and three phenological growth stages. We observed that hazelnut yield exhibits considerable variability depending on the phenological and sub-regional and the microclimate conditions in the humid-temperate Black Sea and the semi-humid Marmara regions. Until the middle of the century, we project that hazelnut yield will decrease up to 13% in approximately half of the current production areas. In addition, the fact that the majority of the decreases will be observed in the eastern Black Sea sub-region will cause hazelnut quality to be adversely affected. These findings are highly relevant in the context of regional development and trade in Turkey, and hazelnut processing and manufacturing sectors abroad.

Climatic Suitability of Different Areas in Abruzzo, Central Italy, for the Cultivation of Hazelnut

“…Besides the type and technical and cultural factors, hazelnut growing is also related to environmental and, particularly, to climatic conditions [3][4][5][6][7][8]. Studies, however, are limited to a few locations and refer to current climatic conditions, despite the long-term nature of the investment connected to cultivation (around 10 years after planting before full production) [3][4][5][6][7][8][9][10]. Hence, the identification of the new areas suitable for hazelnut farming should be based also on the projected trends of the impacts of thermal and precipitation regimes [6].…”

The HADES Yield Prediction System – A Case Study on the Turkish Hazelnut Sector

“…The elaboration of a new index to understand the outliers of the expected on-off sequence allowed identifying anomalies in the yield data series: the cause of such outliers requires a dedicated investigation in the future. As a preliminary explanation, it needs to be highlighted that the exceptionally low yield in 2004 and the occurrence of the unexpected off year in 2014 in the Eastern municipalities were probably associated with late frost events which caused serious damage to the yield ( Erdogan and Aygun, 2017 ; An et al, 2020 ). The cold stress function implemented in the HAZEL model ( Supplementary Material 2 ) allowed capturing these events, as well as the occurrence of cold stress in 2012, which lays the basis for an extended evaluation of the sensitivity of hazelnut trees to cold stresses, based on site-specific weather, phenological and yield data.…”

Climate change impacts on phenology and yield of hazelnut in Australia

“…A few studies already pointed out the influence of climate change on hazelnut tree cultivation. An et al (2020) projected that the hazelnut yield will decrease up to 13% in around half of the actual production areas using multiple regressions between yield and climatic variables. However, the study did not investigate the physiological reasons behind the decrease, which might help farmers/managers to implement proper adaptation strategies.…”