The objective of this study was to develop allometric models for estimating the biomass of <em>Sclerocarya birrea</em> (A.Rich) Hoscht and <em>Boscia senegalensis</em> (Pers.) Lam. ex Poir. The...The objective of this study was to develop allometric models for estimating the biomass of <em>Sclerocarya birrea</em> (A.Rich) Hoscht and <em>Boscia senegalensis</em> (Pers.) Lam. ex Poir. The inventory of these ligneous was carried out at Widou Thiengoly (North of Senegal). The sample consists of 43 individuals of Boscia senegalensis and 15 individuals of <em>Sclerocarya birrea</em>. The selected individuals were dendrometrically characterized before being cut, compartmentalized (trunk, branches, and twigs) and weighed entirely. Simple regression tests were performed to examine the most explanatory dendrometric parameter (<em>x</em>) for biomass (<em>y</em>) according to two types of models: the linear model (<em>y</em> = <em>ax</em> + <em>b</em>) and the polynomial model of degrees 2 (<em>y </em>= <em>ax</em><sup>2</sup> + <em>bx</em> + <em>c</em>). The criteria for selection and validity of the models are based firstly on the tests of normality, nullity, heterogeneity and autocorrelation of the residues. The results showed that the most explanatory dendrometric parameter of the biomass was the crown surface for <em>Boscia senegalensis</em> and the 1.30 m diameter for <em>Sclerocarya birrea</em> of all the tests performed, the second-order Polynomial model is the best predictor of above ground biomass for these two species. Thus, the allometric models established to predict the biomass of these two species are: <em>y</em> = 0.0023<em>x</em><sup>2</sup> + 0.4851<em>x</em> - 0.0519 for <em>Boscia senegalensis</em> and y = 0.35<em>x</em><sup>2</sup> + 10.35<em>x</em> - 12.90 for <em>S. birrea</em>;with very significant correlation coefficients (R<sup>2</sup>) of 0.85 and 0.94 respectively. These results can be used for a sequestered carbon assessment study and will play a role in monitoring the carbon market in Africa.展开更多
The objective of this study is to analyze the dendrochronological potential of two Sahelian species (<i><span style="font-family:Verdana;">B. senegalensis</span></i><span style=&qu...The objective of this study is to analyze the dendrochronological potential of two Sahelian species (<i><span style="font-family:Verdana;">B. senegalensis</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">S. birrea</span></i><span style="font-family:Verdana;">) and to evaluate the rela</span><span style="font-family:Verdana;">tionships between their growth rings and the climate. The study was con</span><span style="font-family:Verdana;">ducted in 2016 in the Ferlo area of Senegal. The biological material consists of wood slices, taken from the trunks of these adult woody species at 0.30 m and 1.30 m from the ground after they have been felled. The technique used to examine the slices consists in identifying their rings, establishing their structures, inter-dating them and studying the relationship between the identified rings and climatic factors. The results showed that the species had thin, clear, highly visible and sharp rings. The limit of growth is marked by a line of parenchyma. Intradatation series carried out on the chronologies made it possible to estimate the ages of the individuals, which vary from 10 to 38 years for </span><i><span style="font-family:Verdana;">B. senegalensis</span></i><span style="font-family:Verdana;"> and from 29 to 50 years for </span><i><span style="font-family:Verdana;">S. birrea</span></i><span style="font-family:Verdana;">. Their average growth </span><span style="font-family:Verdana;">rates are estimated at 0.906 mm/year and 0.89 mm/year respectively. The </span><span style="font-family:Verdana;">chronological sequences are 29 years (1987-2016) for </span><i><span style="font-family:Verdana;">B. senegalensis</span></i><span style="font-family:Verdana;"> and 38 years (1964-2012) for </span><i><span style="font-family:Verdana;">S. birrea</span></i><span style="font-family:Verdana;">. The results revealed that there is no significant correlation between the growth chronologies of </span><i><span style="font-family:Verdana;">B. senegal展开更多
In a context of climate change characterized by rising temperatures, increased greenhouse gases and frequent droughts, the Sahel is presented as one of the most vulnerable areas to the adverse effects of climate chang...In a context of climate change characterized by rising temperatures, increased greenhouse gases and frequent droughts, the Sahel is presented as one of the most vulnerable areas to the adverse effects of climate change. The Sahel is presented as one of the most vulnerable areas to the adverse effects of climate change. The objective of this study is to assess the above-ground biomass and carbon stock of three Sahelian species: <em>Acacia raddiana</em> tortilis (Forsk.) hayne ssp. raddiana (savi) Brenan, <em>Acacia senegal</em> (L.) Willd and <em>Balanites aegyptiaca</em> (L.). The study was carried out in northern Senegal commonly known as Ferlo. Biomasses of the populations of the three target species were first assessed by harvesting the entire epigenetic part of the species and then modelled by correlation using dendrometric parameters measured on each individual of the sample. Two models, mono-specific and multi-species, were used. The results obtained showed that the diameter at breast height (<em>x</em>) and the parameter best correlated to the epigeal biomass (<em>y</em>). The dry biomass of woody plants was 31.4 ± 15.2 kg/tree for <em>B. aegyptiaca</em>, 30.6 ± 13.2 kg/tree for <em>A. senegal</em> and 26.2 ± 11.1 kg/tree for <em>A. raddiana</em>;<em>i.e</em>. carbon equivalents of 14.75 - 14.38 - 12.31 kg/tree respectively. The amount of carbon contained in the above-ground woody biomass is estimated at 4.48 t/ha. The carbon equivalent, atmospheric CO<sub>2</sub> is estimated at 16.44 tons of CO<sub>2</sub>/ha and based on the actual density of Ferlo (108.08 ± 49.79 ind/ha) the sequestered carbon of the area is estimated at 1777.008 tons of CO<sub>2</sub>. The comparison between the models developed in this study and the multispecific or mono-specific models from the literature showed substantial differences. This study contributes to a better understanding of the contribution of Sahelian woody species to carbon sequestration and the results could be used in the framework of adaptation to climate chan展开更多
文摘The objective of this study was to develop allometric models for estimating the biomass of <em>Sclerocarya birrea</em> (A.Rich) Hoscht and <em>Boscia senegalensis</em> (Pers.) Lam. ex Poir. The inventory of these ligneous was carried out at Widou Thiengoly (North of Senegal). The sample consists of 43 individuals of Boscia senegalensis and 15 individuals of <em>Sclerocarya birrea</em>. The selected individuals were dendrometrically characterized before being cut, compartmentalized (trunk, branches, and twigs) and weighed entirely. Simple regression tests were performed to examine the most explanatory dendrometric parameter (<em>x</em>) for biomass (<em>y</em>) according to two types of models: the linear model (<em>y</em> = <em>ax</em> + <em>b</em>) and the polynomial model of degrees 2 (<em>y </em>= <em>ax</em><sup>2</sup> + <em>bx</em> + <em>c</em>). The criteria for selection and validity of the models are based firstly on the tests of normality, nullity, heterogeneity and autocorrelation of the residues. The results showed that the most explanatory dendrometric parameter of the biomass was the crown surface for <em>Boscia senegalensis</em> and the 1.30 m diameter for <em>Sclerocarya birrea</em> of all the tests performed, the second-order Polynomial model is the best predictor of above ground biomass for these two species. Thus, the allometric models established to predict the biomass of these two species are: <em>y</em> = 0.0023<em>x</em><sup>2</sup> + 0.4851<em>x</em> - 0.0519 for <em>Boscia senegalensis</em> and y = 0.35<em>x</em><sup>2</sup> + 10.35<em>x</em> - 12.90 for <em>S. birrea</em>;with very significant correlation coefficients (R<sup>2</sup>) of 0.85 and 0.94 respectively. These results can be used for a sequestered carbon assessment study and will play a role in monitoring the carbon market in Africa.
文摘The objective of this study is to analyze the dendrochronological potential of two Sahelian species (<i><span style="font-family:Verdana;">B. senegalensis</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">S. birrea</span></i><span style="font-family:Verdana;">) and to evaluate the rela</span><span style="font-family:Verdana;">tionships between their growth rings and the climate. The study was con</span><span style="font-family:Verdana;">ducted in 2016 in the Ferlo area of Senegal. The biological material consists of wood slices, taken from the trunks of these adult woody species at 0.30 m and 1.30 m from the ground after they have been felled. The technique used to examine the slices consists in identifying their rings, establishing their structures, inter-dating them and studying the relationship between the identified rings and climatic factors. The results showed that the species had thin, clear, highly visible and sharp rings. The limit of growth is marked by a line of parenchyma. Intradatation series carried out on the chronologies made it possible to estimate the ages of the individuals, which vary from 10 to 38 years for </span><i><span style="font-family:Verdana;">B. senegalensis</span></i><span style="font-family:Verdana;"> and from 29 to 50 years for </span><i><span style="font-family:Verdana;">S. birrea</span></i><span style="font-family:Verdana;">. Their average growth </span><span style="font-family:Verdana;">rates are estimated at 0.906 mm/year and 0.89 mm/year respectively. The </span><span style="font-family:Verdana;">chronological sequences are 29 years (1987-2016) for </span><i><span style="font-family:Verdana;">B. senegalensis</span></i><span style="font-family:Verdana;"> and 38 years (1964-2012) for </span><i><span style="font-family:Verdana;">S. birrea</span></i><span style="font-family:Verdana;">. The results revealed that there is no significant correlation between the growth chronologies of </span><i><span style="font-family:Verdana;">B. senegal
文摘In a context of climate change characterized by rising temperatures, increased greenhouse gases and frequent droughts, the Sahel is presented as one of the most vulnerable areas to the adverse effects of climate change. The Sahel is presented as one of the most vulnerable areas to the adverse effects of climate change. The objective of this study is to assess the above-ground biomass and carbon stock of three Sahelian species: <em>Acacia raddiana</em> tortilis (Forsk.) hayne ssp. raddiana (savi) Brenan, <em>Acacia senegal</em> (L.) Willd and <em>Balanites aegyptiaca</em> (L.). The study was carried out in northern Senegal commonly known as Ferlo. Biomasses of the populations of the three target species were first assessed by harvesting the entire epigenetic part of the species and then modelled by correlation using dendrometric parameters measured on each individual of the sample. Two models, mono-specific and multi-species, were used. The results obtained showed that the diameter at breast height (<em>x</em>) and the parameter best correlated to the epigeal biomass (<em>y</em>). The dry biomass of woody plants was 31.4 ± 15.2 kg/tree for <em>B. aegyptiaca</em>, 30.6 ± 13.2 kg/tree for <em>A. senegal</em> and 26.2 ± 11.1 kg/tree for <em>A. raddiana</em>;<em>i.e</em>. carbon equivalents of 14.75 - 14.38 - 12.31 kg/tree respectively. The amount of carbon contained in the above-ground woody biomass is estimated at 4.48 t/ha. The carbon equivalent, atmospheric CO<sub>2</sub> is estimated at 16.44 tons of CO<sub>2</sub>/ha and based on the actual density of Ferlo (108.08 ± 49.79 ind/ha) the sequestered carbon of the area is estimated at 1777.008 tons of CO<sub>2</sub>. The comparison between the models developed in this study and the multispecific or mono-specific models from the literature showed substantial differences. This study contributes to a better understanding of the contribution of Sahelian woody species to carbon sequestration and the results could be used in the framework of adaptation to climate chan
