Tree rings depend on seasonal variation in radial tree growth. Where they can be identified, their interannual variation may reflect climate variability. Compared to its use in temperate and boreal regions, tree-ring analysis has been less applied in tropical Africa, with weaker seasonality. Daniellia oliveri often forms the tallest trees in agroforestry parklands of the Sudanian savanna zone of Mali but its growth response to climate (rainfall, temperature) variability has not been documented. We analyzed six stem disks of D. oliveri and used standard dendrochronological methods to process the samples. Contrary to earlier literature likely based on more humid parts of the species distribution range, D. oliveri formed distinct growth ring boundaries in our study area. The mean annual radial growth was 2.73 ± 0.56 mm. All measured tree-ring series were successfully cross-dated with a GLK (Gleichläufigkeit) value of 76.3 ± 5.6. The final tree-ring chronology covers the period 1909-2021. After removing age-related growth trends, the tree-ring width index showed a significant relationship with records of annual rainfall (r2 = 0.46, n = 100 years, p < 0.001). The relationship between wet-season (June to September) precipitation and the residual chronology was slightly higher (r2 = 0.50, n = 100 years, p < 0.001). However, no significant correlation was found for temperature. These results imply that D. oliveri can be successfully used for dendrochronological studies with relevance for the management and restoration of the ecosystems in the Sudanian zone of West Africa, where long-term rainfall records are scarce.
Tag: climate change
Climate-growth relationships of Daniellia oliveri (Rolfe) Hutch. & Dalziel in the Sudanian zone of Mali, West Africa
Tree rings depend on seasonal variation in radial tree growth. Where they can be identified, their interannual variation may reflect climate variability. Compared to its use in temperate and boreal regions, tree-ring analysis has been less applied in tropical Africa, with weaker seasonality. Daniellia oliveri often forms the tallest trees in agroforestry parklands of the Sudanian savanna zone of Mali but its growth response to climate (rainfall, temperature) variability has not been documented. We analyzed six stem disks of D. oliveri and used standard dendrochronological methods to process the samples. Contrary to earlier literature likely based on more humid parts of the species distribution range, D. oliveri formed distinct growth ring boundaries in our study area. The mean annual radial growth was 2.73 ± 0.56 mm. All measured tree-ring series were successfully cross-dated with a GLK (Gleichläufigkeit) value of 76.3 ± 5.6. The final tree-ring chronology covers the period 1909-2021. After removing age-related growth trends, the tree-ring width index showed a significant relationship with records of annual rainfall (r2 = 0.46, n = 100 years, p < 0.001). The relationship between wet-season (June to September) precipitation and the residual chronology was slightly higher (r2 = 0.50, n = 100 years, p < 0.001). However, no significant correlation was found for temperature. These results imply that D. oliveri can be successfully used for dendrochronological studies with relevance for the management and restoration of the ecosystems in the Sudanian zone of West Africa, where long-term rainfall records are scarce.
Climate-growth relationships of Daniellia oliveri (Rolfe) Hutch. & Dalziel in the Sudanian zone of Mali, West Africa
Tree rings depend on seasonal variation in radial tree growth. Where they can be identified, their interannual variation may reflect climate variability. Compared to its use in temperate and boreal regions, tree-ring analysis has been less applied in tropical Africa, with weaker seasonality. Daniellia oliveri often forms the tallest trees in agroforestry parklands of the Sudanian savanna zone of Mali but its growth response to climate (rainfall, temperature) variability has not been documented. We analyzed six stem disks of D. oliveri and used standard dendrochronological methods to process the samples. Contrary to earlier literature likely based on more humid parts of the species distribution range, D. oliveri formed distinct growth ring boundaries in our study area. The mean annual radial growth was 2.73 ± 0.56 mm. All measured tree-ring series were successfully cross-dated with a GLK (Gleichläufigkeit) value of 76.3 ± 5.6. The final tree-ring chronology covers the period 1909-2021. After removing age-related growth trends, the tree-ring width index showed a significant relationship with records of annual rainfall (r2 = 0.46, n = 100 years, p < 0.001). The relationship between wet-season (June to September) precipitation and the residual chronology was slightly higher (r2 = 0.50, n = 100 years, p < 0.001). However, no significant correlation was found for temperature. These results imply that D. oliveri can be successfully used for dendrochronological studies with relevance for the management and restoration of the ecosystems in the Sudanian zone of West Africa, where long-term rainfall records are scarce.
Climate-growth relationships of Daniellia oliveri (Rolfe) Hutch. & Dalziel in the Sudanian zone of Mali, West Africa
Tree rings depend on seasonal variation in radial tree growth. Where they can be identified, their interannual variation may reflect climate variability. Compared to its use in temperate and boreal regions, tree-ring analysis has been less applied in tropical Africa, with weaker seasonality. Daniellia oliveri often forms the tallest trees in agroforestry parklands of the Sudanian savanna zone of Mali but its growth response to climate (rainfall, temperature) variability has not been documented. We analyzed six stem disks of D. oliveri and used standard dendrochronological methods to process the samples. Contrary to earlier literature likely based on more humid parts of the species distribution range, D. oliveri formed distinct growth ring boundaries in our study area. The mean annual radial growth was 2.73 ± 0.56 mm. All measured tree-ring series were successfully cross-dated with a GLK (Gleichläufigkeit) value of 76.3 ± 5.6. The final tree-ring chronology covers the period 1909-2021. After removing age-related growth trends, the tree-ring width index showed a significant relationship with records of annual rainfall (r2 = 0.46, n = 100 years, p < 0.001). The relationship between wet-season (June to September) precipitation and the residual chronology was slightly higher (r2 = 0.50, n = 100 years, p < 0.001). However, no significant correlation was found for temperature. These results imply that D. oliveri can be successfully used for dendrochronological studies with relevance for the management and restoration of the ecosystems in the Sudanian zone of West Africa, where long-term rainfall records are scarce.
Climate variability impacts on growth of African grape (Lannea microcarpa Engl & K. Krause) in West Africa
Lannea microcarpa is a deciduous tree with high socio-economic value in West African agroforestry systems. While climate-growth relationships remain unknown, this species is exposed to climate extremes. Knowledge of its response to climate variations is needed for its sustainable management. Therefore, the present study aimed to examine the growth of Lannea microcarpa in two climatic zones in West Africa (Sudanian zone of Mali and Sudano-Sahelian zone of Burkina Faso) using standard dendrochronological methods. In both sites, Lannea microcarpa forms distinct growth ring-boundaries characterized by a wider band with more parenchyma cell rows and is also marked by its solitary vessels. The two standard chronologies developed were significantly correlated with the precipitation records in both Burkina Faso (r2 = 0.41, n = 30 years, p < 0.01) and Mali (r2 =0.60, n = 53 years, p < 0.001). Furthermore, a strong relationship between major seasonal precipitation (between June and September) and residual chronology was observed in Burkina Faso (r2 = 0.51, n = 28 years, p < 0.01) and Mali (r2 = 0.65, n = 52 years, p < 0.001). The formation of annual growth rings is clearly influenced by climate variability, but not all variance is accounted for. The insignificant correlation between the chronologies of the two regions may be due to various factors, including differences in climate factors and soil conditions influencing buffered water availability. Similar studies on other tree species in West Africa will be useful.
Scaling & Enhancing Restoration Impact Through Gender Transformative Approaches
Regreening Africa enhances resilience in the Sahel and Horn of Africa by addressing climate change, land degradation, and food insecurity. Through a broad partnership network, the initiative scales context-appropriate land restoration by integrating trees and sustainable practices into farming and pastoral systems. Phase II expands efforts in Somalia, Ethiopia, Senegal, Nigeria, Ghana, Mali, and Niger, focusing on systems scaling for transformative change. Building on Phase I, this phase promotes agroforestry, FMNR, soil and water conservation, soil health improvement, grazing management, and energy-efficient cookstoves to boost land productivity and resilience, particularly in rangeland and mixed landscapes.
Scaling & Enhancing Restoration Impact Through Gender Transformative Approaches
Regreening Africa enhances resilience in the Sahel and Horn of Africa by addressing climate change, land degradation, and food insecurity. Through a broad partnership network, the initiative scales context-appropriate land restoration by integrating trees and sustainable practices into farming and pastoral systems. Phase II expands efforts in Somalia, Ethiopia, Senegal, Nigeria, Ghana, Mali, and Niger, focusing on systems scaling for transformative change. Building on Phase I, this phase promotes agroforestry, FMNR, soil and water conservation, soil health improvement, grazing management, and energy-efficient cookstoves to boost land productivity and resilience, particularly in rangeland and mixed landscapes.
Climate variability impacts on growth of African grape (Lannea microcarpa Engl & K. Krause) in West Africa
Lannea microcarpa is a deciduous tree with high socio-economic value in West African agroforestry systems. While climate-growth relationships remain unknown, this species is exposed to climate extremes. Knowledge of its response to climate variations is needed for its sustainable management. Therefore, the present study aimed to examine the growth of Lannea microcarpa in two climatic zones in West Africa (Sudanian zone of Mali and Sudano-Sahelian zone of Burkina Faso) using standard dendrochronological methods. In both sites, Lannea microcarpa forms distinct growth ring-boundaries characterized by a wider band with more parenchyma cell rows and is also marked by its solitary vessels. The two standard chronologies developed were significantly correlated with the precipitation records in both Burkina Faso (r2 = 0.41, n = 30 years, p < 0.01) and Mali (r2 =0.60, n = 53 years, p < 0.001). Furthermore, a strong relationship between major seasonal precipitation (between June and September) and residual chronology was observed in Burkina Faso (r2 = 0.51, n = 28 years, p < 0.01) and Mali (r2 = 0.65, n = 52 years, p < 0.001). The formation of annual growth rings is clearly influenced by climate variability, but not all variance is accounted for. The insignificant correlation between the chronologies of the two regions may be due to various factors, including differences in climate factors and soil conditions influencing buffered water availability. Similar studies on other tree species in West Africa will be useful.
Climate variability impacts on growth of African grape (Lannea microcarpa Engl & K. Krause) in West Africa
Lannea microcarpa is a deciduous tree with high socio-economic value in West African agroforestry systems. While climate-growth relationships remain unknown, this species is exposed to climate extremes. Knowledge of its response to climate variations is needed for its sustainable management. Therefore, the present study aimed to examine the growth of Lannea microcarpa in two climatic zones in West Africa (Sudanian zone of Mali and Sudano-Sahelian zone of Burkina Faso) using standard dendrochronological methods. In both sites, Lannea microcarpa forms distinct growth ring-boundaries characterized by a wider band with more parenchyma cell rows and is also marked by its solitary vessels. The two standard chronologies developed were significantly correlated with the precipitation records in both Burkina Faso (r2 = 0.41, n = 30 years, p < 0.01) and Mali (r2 =0.60, n = 53 years, p < 0.001). Furthermore, a strong relationship between major seasonal precipitation (between June and September) and residual chronology was observed in Burkina Faso (r2 = 0.51, n = 28 years, p < 0.01) and Mali (r2 = 0.65, n = 52 years, p < 0.001). The formation of annual growth rings is clearly influenced by climate variability, but not all variance is accounted for. The insignificant correlation between the chronologies of the two regions may be due to various factors, including differences in climate factors and soil conditions influencing buffered water availability. Similar studies on other tree species in West Africa will be useful.
Climate-growth relationships of Daniellia oliveri (Rolfe) Hutch. & Dalziel in the Sudanian zone of Mali, West Africa
Tree rings depend on seasonal variation in radial tree growth. Where they can be identified, their interannual variation may reflect climate variability. Compared to its use in temperate and boreal regions, tree-ring analysis has been less applied in tropical Africa, with weaker seasonality. Daniellia oliveri often forms the tallest trees in agroforestry parklands of the Sudanian savanna zone of Mali but its growth response to climate (rainfall, temperature) variability has not been documented. We analyzed six stem disks of D. oliveri and used standard dendrochronological methods to process the samples. Contrary to earlier literature likely based on more humid parts of the species distribution range, D. oliveri formed distinct growth ring boundaries in our study area. The mean annual radial growth was 2.73 ± 0.56 mm. All measured tree-ring series were successfully cross-dated with a GLK (Gleichläufigkeit) value of 76.3 ± 5.6. The final tree-ring chronology covers the period 1909-2021. After removing age-related growth trends, the tree-ring width index showed a significant relationship with records of annual rainfall (r2 = 0.46, n = 100 years, p < 0.001). The relationship between wet-season (June to September) precipitation and the residual chronology was slightly higher (r2 = 0.50, n = 100 years, p < 0.001). However, no significant correlation was found for temperature. These results imply that D. oliveri can be successfully used for dendrochronological studies with relevance for the management and restoration of the ecosystems in the Sudanian zone of West Africa, where long-term rainfall records are scarce.