Publicação
Study of climate change impacts and the adaptation measures in agricultural, chestnut and almond species, in Portuguese territory
| Resumo: | The chestnut (Castanea spp.) and almond (Prunus dulcis) are species of high food and socioeconomic value worldwide. Their fruits are highly sought after due to their nutritional interest. For this reason, the increased trade routes and the intensification of planting in several regions allowed the species to undergo genetic improvement and adaptive capacity optimization for different climate conditions. Castanea spp is a mesophilic genus from warm temperate climates, with moderate temperature. In 2021, the chestnut tree area worldwide was approximately 568.2×103 ha for fruit production (Southern Europe, Southwestern United States of America, and Asia). In Europe, 319.5×103 t of Castanea sativa were produced and five genetic poles can be identified on the continent. Portugal is the third country in the world with the largest chestnut area (50.3×103 ha), with a production of 37.2×103 t. Prunus dulcis growth in Mediterranean-type climates, which is defined by hot and dry summers and relatively cool and moist winters. In 2021, the world almond production was approximately 3.9×106 t. Thus, the continent with the highest production of almonds is America, followed by Asia and Europe, Africa, and Oceania. Due to the beneficial climate conditions and the improvement of production techniques and practices, Portugal has shown an increasing evolution in almond production. The country is the second largest producer by area (58.4×103 ha) in Europe, with a production of 41.5×103 t. Over the years, the production variations of these species have been linked to the climate, which is a driver of biodiversity and ecosystem change. Climate change is one of the most emergent environmental challenges, with rising global temperatures, changes in precipitation regimes, and an increased frequency and intensity of extreme weather events. In the future, it is expected that challenges will be aggravated, which could threaten these crops' sustainability. Therefore, it is essential to identify the impacts of climate change on these species, improving our current understanding of climate-tree interconnections. In this thesis, studies of the impacts of climate change on chestnut and almond growing was carried out and possible adaptation strategies that may be relevant for producers and other stakeholders in this value chain were considers. The first pratical study was conducted using bioclimatic indices that identify the optimum regions for the spatial distribution of chestnut trees in mainland Portugal, in the recent-past and future periods. For this, the bioclimatic indices selected consider the optimal growing climatic conditions for the chestnut growth: growing degree days between 1900 and 2400 ºC (GDD), annual mean temperature from 8 to 15 ºC (AMT), summer days with maximum temperatures below 32 °C (NXT), annual precipitation between 600 and 1600mm (PRE). Moreover, Chestnut Suitability Index (CSI) was developed, which takes into account the previous parameters in the same proportion, and summarises the climatic suitability conditions of the regions for the species growth. According to the results, in the recent-past, the chestnut tree was mostly distributed in the north and west of the country, especially in regions with higher altitudes. The centre and south were the regions with the smallest areas of chestnut trees. For the future climate, there was a reduction in an area favourable to species growth. Only, a small region in the north of the country may be 100% suitable due to changes in bioclimatic conditions. The second study focused on the agrarian region of Trás-os-Montes (TM; northeast Portugal), which is a traditional almond-growing area. The chilling and forcing conditions in TM were evaluated, for the recent-past and future periods, taking into account the different varietal phenological seasons. Successful flowering and production require compliance with chill and heat accumulation, which are directly related to air temperature. To determine chill accumulation, the Dynamic Model/chill portions (CP) and chilling hour (CH) models were used. For heat accumulation, the growing degree hours (GDH) and growing degree days (GDD) models were selected. According to the results, for the future, while estimates for GDH and GDD show an increase in heat conditions until early summer, projections for CP and CH show declines. According to GDH, high summer temperatures could be detrimental. CP and GDH may be more accurate in capturing the effects of climate change. Compared to the early and intermediate cultivars, the late cultivar for all three varietal groups may show a greater decline in CP and GDH. However, the increase in forced heat may be more detrimental than the decrease in chill conditions. The implementation of adaptation measures is key to the sustainability of the two species under analysis and is a useful tool for crop management by farmers and stakeholders. |
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| Autores principais: | Freitas, Teresa Raquel Macedo de |
| Assunto: | adaptation measures climate change impacts Castanea sativa Prunus dulcis bioclimatic distribution thermal conditions |
| Ano: | 2024 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Trás-os-Montes e Alto Douro |
| Idioma: | inglês |
| Origem: | Repositório da UTAD |
| Resumo: | The chestnut (Castanea spp.) and almond (Prunus dulcis) are species of high food and socioeconomic value worldwide. Their fruits are highly sought after due to their nutritional interest. For this reason, the increased trade routes and the intensification of planting in several regions allowed the species to undergo genetic improvement and adaptive capacity optimization for different climate conditions. Castanea spp is a mesophilic genus from warm temperate climates, with moderate temperature. In 2021, the chestnut tree area worldwide was approximately 568.2×103 ha for fruit production (Southern Europe, Southwestern United States of America, and Asia). In Europe, 319.5×103 t of Castanea sativa were produced and five genetic poles can be identified on the continent. Portugal is the third country in the world with the largest chestnut area (50.3×103 ha), with a production of 37.2×103 t. Prunus dulcis growth in Mediterranean-type climates, which is defined by hot and dry summers and relatively cool and moist winters. In 2021, the world almond production was approximately 3.9×106 t. Thus, the continent with the highest production of almonds is America, followed by Asia and Europe, Africa, and Oceania. Due to the beneficial climate conditions and the improvement of production techniques and practices, Portugal has shown an increasing evolution in almond production. The country is the second largest producer by area (58.4×103 ha) in Europe, with a production of 41.5×103 t. Over the years, the production variations of these species have been linked to the climate, which is a driver of biodiversity and ecosystem change. Climate change is one of the most emergent environmental challenges, with rising global temperatures, changes in precipitation regimes, and an increased frequency and intensity of extreme weather events. In the future, it is expected that challenges will be aggravated, which could threaten these crops' sustainability. Therefore, it is essential to identify the impacts of climate change on these species, improving our current understanding of climate-tree interconnections. In this thesis, studies of the impacts of climate change on chestnut and almond growing was carried out and possible adaptation strategies that may be relevant for producers and other stakeholders in this value chain were considers. The first pratical study was conducted using bioclimatic indices that identify the optimum regions for the spatial distribution of chestnut trees in mainland Portugal, in the recent-past and future periods. For this, the bioclimatic indices selected consider the optimal growing climatic conditions for the chestnut growth: growing degree days between 1900 and 2400 ºC (GDD), annual mean temperature from 8 to 15 ºC (AMT), summer days with maximum temperatures below 32 °C (NXT), annual precipitation between 600 and 1600mm (PRE). Moreover, Chestnut Suitability Index (CSI) was developed, which takes into account the previous parameters in the same proportion, and summarises the climatic suitability conditions of the regions for the species growth. According to the results, in the recent-past, the chestnut tree was mostly distributed in the north and west of the country, especially in regions with higher altitudes. The centre and south were the regions with the smallest areas of chestnut trees. For the future climate, there was a reduction in an area favourable to species growth. Only, a small region in the north of the country may be 100% suitable due to changes in bioclimatic conditions. The second study focused on the agrarian region of Trás-os-Montes (TM; northeast Portugal), which is a traditional almond-growing area. The chilling and forcing conditions in TM were evaluated, for the recent-past and future periods, taking into account the different varietal phenological seasons. Successful flowering and production require compliance with chill and heat accumulation, which are directly related to air temperature. To determine chill accumulation, the Dynamic Model/chill portions (CP) and chilling hour (CH) models were used. For heat accumulation, the growing degree hours (GDH) and growing degree days (GDD) models were selected. According to the results, for the future, while estimates for GDH and GDD show an increase in heat conditions until early summer, projections for CP and CH show declines. According to GDH, high summer temperatures could be detrimental. CP and GDH may be more accurate in capturing the effects of climate change. Compared to the early and intermediate cultivars, the late cultivar for all three varietal groups may show a greater decline in CP and GDH. However, the increase in forced heat may be more detrimental than the decrease in chill conditions. The implementation of adaptation measures is key to the sustainability of the two species under analysis and is a useful tool for crop management by farmers and stakeholders. |
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