In order to know the role of plant woody debris in the carbon cycle, a study of carbon stocks and carbon flow of plant woody debris was conducted in the natural forests of the centre of the republic of Congo in the Ba...In order to know the role of plant woody debris in the carbon cycle, a study of carbon stocks and carbon flow of plant woody debris was conducted in the natural forests of the centre of the republic of Congo in the Bateke Plateau. Allometric equations were used to measure the carbon stock of in dead wood debris of Lesio-louna tropical rainforest. Three plots of 40 m × 40 m were delimited in each forest types. All plots were within 300 m of each other. The average stocks of carbon in coarse woody debris obtained are 10993 g·m-2 and 14172 g·m-2, respectively, in the Gallery forest (GF) and the hill-slope forest clump (HF), the difference of carbon stock between the two forests is not significant (p = 0.78). The interannual mean flow in both forests is respectively 1776 and 545 g·m-2·an-1 in the FG and the MSDS;this medium is not significant (p = 0.10). Carbon stocks of fine woody debris are respectively 965 and 83 g·m-2 in the GF and HF, difference is significant (p = 0.0013). The interannual mean flow of carbon in fine woody debris in the GF and the HF were respectively 310 g·m-2·an-1 and 51 g·m-2·an-1.展开更多
Stem density and size stratification of woody species are informative of vegetation conditions and its physiognomy in savannah whereas their variation influence woody population functioning. Current study endeavoured ...Stem density and size stratification of woody species are informative of vegetation conditions and its physiognomy in savannah whereas their variation influence woody population functioning. Current study endeavoured to evaluate the stand density and size variability of woody species related to aboveground biomass in a Sudanian savannah. Total height, stem diameter at breast height (dbh) ≥ 5 cm were measured in 30 plots of 50 m </span></span><span><span><span style="font-family:"">×<span> 20 m laid in respect to vegetation type as bowal, shrubland and woodland. Species diversity, stem density, height and basal area were calculated and compared across sites and variation in stem dbh classes evaluated. Total aboveground biomass was estimated and thereafter linear relationships were established between stand density and aboveground biomass</span></span></span></span><span><span><span style="font-family:"">,</span></span></span><span><span><span style="font-family:""> and basal area. Results revealed three different sites with an overall 58 species identified through vegetation type including liana species (4 stems in bowal) with 18 genera and 42 families. Fabaceae Combretaceae, Anacardiaceae and Rubiaceae were dominant families. Small sized trees represented 72% of total stem density considered in structure with significant higher basal area, while large sized trees as 28% were scarcely distributed. More than 70% variation in biomass w</span></span></span><span><span><span style="font-family:"">as </span></span></span><span><span><span style="font-family:"">due to stem density and basal area with a dominance of small trees. In conclusion increase size in tree community indicated increase in accumulated aboveground biomass as positive regeneration features. But, change in vegetation structure strongly influence negatively species ability to grow from lower to upper size class and later on, disrupt ecosystem functioning. Plant stem density and stratification could be considered as indicators of aboveground biomass fluctuating in regeneration monitoring.展开更多
Based on 120 stem discs collected during3 months of fieldwork along a 12 km route,the history of fires in the Wari Maro Forest（09 1000 N–02 1000E） over the past century in savanna woodland and dry forest was recons...Based on 120 stem discs collected during3 months of fieldwork along a 12 km route,the history of fires in the Wari Maro Forest（09 1000 N–02 1000E） over the past century in savanna woodland and dry forest was reconstituted.Three major ecological areas are characterized：one highly burnt zone located between two relative less burnt areas.By analyzing tree rings,246 fire scars were identified.The scars were caused by 51 fire years,occurring at a mean interval of 2.23 years.From 1890 to1965,only 6 years with fires were recorded from sampled trees.Since 1966,no year has passed without fire.The fire frequency point scale reached 14 years.This was the case of Burkea africana,which has been identified as a species tolerant to fire and could be planted to create a natural firewall.In contrast,Anogeissus leiocarpa is highly sensitive to fire,and in a dry forest ecosystem that burns seasonally,it requires a special conservation plan.Two new concepts are described：the rebarking of trees after fire and Mean Kilometer Fire Interval.The first concept was tested with Daniellia oliveri（Rolfe） Hutch ＆ Dalz trees,and the second concept was used to evaluate spatial fire distribution.We demonstrate that savanna woodland and dry forest were subject to a degradation process caused by destructive fires related to vegetation cover clearance and illegal logging.展开更多
The diversity, abundance and height structure of naturally regenerated woody species were analyzed and compared for undergrowth reservoir associated with vegetation patches as bowal, shrubland and woodland for underst...The diversity, abundance and height structure of naturally regenerated woody species were analyzed and compared for undergrowth reservoir associated with vegetation patches as bowal, shrubland and woodland for understanding the effect of vegetation conditions on spatial distribution of woody plants in Sudanian ecosystem. All undergrowth individuals (height < 1.5 m) were recorded by species and the total height and collar diameter were measured in 50 subplots of 5 m × 5 m (or 25 m<sup>2</sup>) laid out in each vegetation patch during rainy season. In total 52 undergrowth species and 2224 stems arranged in 38 genera and 21 families out of which 25, 36 and 38 species were found in bowal, shrubland and woodland respectively and 15 shared species. Combretaceae, Caesalpiniaceae and Mimosaceae families were the most abundant and species density was significantly higher (P < 0.05) in shrubland and woodland than bowal, and increase diversity in only shrubland (P = 0.002) comparing with bowal. Undergrowth was abundantly concentrated in small height class as canopy benefit and indicate a specific-site distribution. Results also showed that bowal had a particular vegetation which vary in function of tree community characters in place (P < 0.05) while woodland and shrubland are similar vegetation patches. As conclusion, the study vegetation patches form suitable regeneration niches for the undergrowth reservoir of limited number of species which in return can be predictor of species richness and abundance and thus the structure of tree community. Woody undergrowth community could be considered in biodiversity management and degraded land restoration. Supplementary works could be undertaken to understand the characteristics of seed bank for bowal, shrubland and woodland regarding the undergrowth and tree communities.展开更多
Fertilization practices can influence the quality of pineapple fruit and consequently its acceptability by consumers who are increasingly oriented towards high quality agri-food products. This study aimed at evaluatin...Fertilization practices can influence the quality of pineapple fruit and consequently its acceptability by consumers who are increasingly oriented towards high quality agri-food products. This study aimed at evaluating the influence of N, P and K on some physico-chemical and organoleptic characteristics of pineapple (Ananas comosus L. Merr) for fresh consumption and juice processing. A complete NPK factorial design was installed in the south Benin. The treatments NPK in g plant-1 were randomized into four blocks: T1;T2;T3;T4;T5;T6;T7;T8;T9. Brix juice was determined using a refractometer and pH with a pH meter. An evaluation of sensory characteristics such as sweetness, acid taste and aroma of fresh pineapple pulp and processed juice was made by a panel of tasters selected and trained. A principal components analysis, followed by a numerical classification was performed on fruits’ sensory and physicochemical characteristics. Results showed that juice pH was significantly influenced by the phosphorus and potassium. Potassium influenced significantly juice yield. Some physico-chemical characteristics and sensory attributes were correlated between them and groups of treatments are formed for both the juice and the fresh fruit.展开更多
Background:Insufficient knowledge of the genetic and phenotypic diversity in the local Beninese goat population combined with the lack of understanding of its adaptive capacity to ongoing environmental and societal ch...Background:Insufficient knowledge of the genetic and phenotypic diversity in the local Beninese goat population combined with the lack of understanding of its adaptive capacity to ongoing environmental and societal changes hampers the development of strategies for better management and genetic improvement.The objective of this study was to establish the current geographical distribution of goats in Benin based on their morphology and model the potential habitat suitability of the three known main goat phenotypes(i.e.,Djallonkégoat or TypeⅠ,Sahelian goat or TypeⅡ,and their Crossbreeds or TypeⅢ)under climate change scenarios.Ten qualitative and 26 linear body measurements were taken on 2114 adult female goats sampled across the three vegetation zones of the country.Fifteen ratios were generated from the quantitative variables.The data were analyzed using generalized linear model procedures followed by multiple comparisons of least-squares means and multivariate analytical methods,including canonical discrimination analysis and hierarchical ascendant classification.Each goat was then assigned to one of the three aforementioned main goat phenotypes following its morphological characteristics and according to the a priori cluster membership defined in the previous step.The Maximum Entropy algorithm was used to model the current and future distribution of the three goat phenotypes under climate change scenario using the Representative Conservation Pathways 4.5 and 8.5.Results:All linear body measurements varied among vegetation zones.In the discriminant function analysis,71%of the measured individuals were correctly classified in their vegetation zone of origin by seven measured variables and three ratios.The cluster procedure analysis revealed two groups of goats subdivided into the three main phenotypes.The modeling results showed that the currently highly favorable habitats were distributed in the South for TypeⅠ,in the North for TypeⅡ,and both South and North for TypeⅢ.However,under climate change scenarios,the favorable habitats for TypeⅠdecreased while those of TypesⅡandⅢincreased.Conclusions:The results of this study confirm the spatial variation of the goat population in Benin.The habitat suitability model can be used to support decision-making toward better management of goat genetic diversity in Benin.展开更多
文摘In order to know the role of plant woody debris in the carbon cycle, a study of carbon stocks and carbon flow of plant woody debris was conducted in the natural forests of the centre of the republic of Congo in the Bateke Plateau. Allometric equations were used to measure the carbon stock of in dead wood debris of Lesio-louna tropical rainforest. Three plots of 40 m × 40 m were delimited in each forest types. All plots were within 300 m of each other. The average stocks of carbon in coarse woody debris obtained are 10993 g·m-2 and 14172 g·m-2, respectively, in the Gallery forest (GF) and the hill-slope forest clump (HF), the difference of carbon stock between the two forests is not significant (p = 0.78). The interannual mean flow in both forests is respectively 1776 and 545 g·m-2·an-1 in the FG and the MSDS;this medium is not significant (p = 0.10). Carbon stocks of fine woody debris are respectively 965 and 83 g·m-2 in the GF and HF, difference is significant (p = 0.0013). The interannual mean flow of carbon in fine woody debris in the GF and the HF were respectively 310 g·m-2·an-1 and 51 g·m-2·an-1.
文摘Stem density and size stratification of woody species are informative of vegetation conditions and its physiognomy in savannah whereas their variation influence woody population functioning. Current study endeavoured to evaluate the stand density and size variability of woody species related to aboveground biomass in a Sudanian savannah. Total height, stem diameter at breast height (dbh) ≥ 5 cm were measured in 30 plots of 50 m </span></span><span><span><span style="font-family:"">×<span> 20 m laid in respect to vegetation type as bowal, shrubland and woodland. Species diversity, stem density, height and basal area were calculated and compared across sites and variation in stem dbh classes evaluated. Total aboveground biomass was estimated and thereafter linear relationships were established between stand density and aboveground biomass</span></span></span></span><span><span><span style="font-family:"">,</span></span></span><span><span><span style="font-family:""> and basal area. Results revealed three different sites with an overall 58 species identified through vegetation type including liana species (4 stems in bowal) with 18 genera and 42 families. Fabaceae Combretaceae, Anacardiaceae and Rubiaceae were dominant families. Small sized trees represented 72% of total stem density considered in structure with significant higher basal area, while large sized trees as 28% were scarcely distributed. More than 70% variation in biomass w</span></span></span><span><span><span style="font-family:"">as </span></span></span><span><span><span style="font-family:"">due to stem density and basal area with a dominance of small trees. In conclusion increase size in tree community indicated increase in accumulated aboveground biomass as positive regeneration features. But, change in vegetation structure strongly influence negatively species ability to grow from lower to upper size class and later on, disrupt ecosystem functioning. Plant stem density and stratification could be considered as indicators of aboveground biomass fluctuating in regeneration monitoring.
基金funded by Deutscher Akademisher Austausch Dienst(DAAD)Biodiversity Monitoring Transect Analysis(BIOTA)project
文摘Based on 120 stem discs collected during3 months of fieldwork along a 12 km route,the history of fires in the Wari Maro Forest（09 1000 N–02 1000E） over the past century in savanna woodland and dry forest was reconstituted.Three major ecological areas are characterized：one highly burnt zone located between two relative less burnt areas.By analyzing tree rings,246 fire scars were identified.The scars were caused by 51 fire years,occurring at a mean interval of 2.23 years.From 1890 to1965,only 6 years with fires were recorded from sampled trees.Since 1966,no year has passed without fire.The fire frequency point scale reached 14 years.This was the case of Burkea africana,which has been identified as a species tolerant to fire and could be planted to create a natural firewall.In contrast,Anogeissus leiocarpa is highly sensitive to fire,and in a dry forest ecosystem that burns seasonally,it requires a special conservation plan.Two new concepts are described：the rebarking of trees after fire and Mean Kilometer Fire Interval.The first concept was tested with Daniellia oliveri（Rolfe） Hutch ＆ Dalz trees,and the second concept was used to evaluate spatial fire distribution.We demonstrate that savanna woodland and dry forest were subject to a degradation process caused by destructive fires related to vegetation cover clearance and illegal logging.
文摘The diversity, abundance and height structure of naturally regenerated woody species were analyzed and compared for undergrowth reservoir associated with vegetation patches as bowal, shrubland and woodland for understanding the effect of vegetation conditions on spatial distribution of woody plants in Sudanian ecosystem. All undergrowth individuals (height < 1.5 m) were recorded by species and the total height and collar diameter were measured in 50 subplots of 5 m × 5 m (or 25 m<sup>2</sup>) laid out in each vegetation patch during rainy season. In total 52 undergrowth species and 2224 stems arranged in 38 genera and 21 families out of which 25, 36 and 38 species were found in bowal, shrubland and woodland respectively and 15 shared species. Combretaceae, Caesalpiniaceae and Mimosaceae families were the most abundant and species density was significantly higher (P < 0.05) in shrubland and woodland than bowal, and increase diversity in only shrubland (P = 0.002) comparing with bowal. Undergrowth was abundantly concentrated in small height class as canopy benefit and indicate a specific-site distribution. Results also showed that bowal had a particular vegetation which vary in function of tree community characters in place (P < 0.05) while woodland and shrubland are similar vegetation patches. As conclusion, the study vegetation patches form suitable regeneration niches for the undergrowth reservoir of limited number of species which in return can be predictor of species richness and abundance and thus the structure of tree community. Woody undergrowth community could be considered in biodiversity management and degraded land restoration. Supplementary works could be undertaken to understand the characteristics of seed bank for bowal, shrubland and woodland regarding the undergrowth and tree communities.
文摘Fertilization practices can influence the quality of pineapple fruit and consequently its acceptability by consumers who are increasingly oriented towards high quality agri-food products. This study aimed at evaluating the influence of N, P and K on some physico-chemical and organoleptic characteristics of pineapple (Ananas comosus L. Merr) for fresh consumption and juice processing. A complete NPK factorial design was installed in the south Benin. The treatments NPK in g plant-1 were randomized into four blocks: T1;T2;T3;T4;T5;T6;T7;T8;T9. Brix juice was determined using a refractometer and pH with a pH meter. An evaluation of sensory characteristics such as sweetness, acid taste and aroma of fresh pineapple pulp and processed juice was made by a panel of tasters selected and trained. A principal components analysis, followed by a numerical classification was performed on fruits’ sensory and physicochemical characteristics. Results showed that juice pH was significantly influenced by the phosphorus and potassium. Potassium influenced significantly juice yield. Some physico-chemical characteristics and sensory attributes were correlated between them and groups of treatments are formed for both the juice and the fresh fruit.
基金This work is financially supported by the Government of Belgium through the"Académie de Recherche et d’Enseignement Supérieur(ARES)".
文摘Background:Insufficient knowledge of the genetic and phenotypic diversity in the local Beninese goat population combined with the lack of understanding of its adaptive capacity to ongoing environmental and societal changes hampers the development of strategies for better management and genetic improvement.The objective of this study was to establish the current geographical distribution of goats in Benin based on their morphology and model the potential habitat suitability of the three known main goat phenotypes(i.e.,Djallonkégoat or TypeⅠ,Sahelian goat or TypeⅡ,and their Crossbreeds or TypeⅢ)under climate change scenarios.Ten qualitative and 26 linear body measurements were taken on 2114 adult female goats sampled across the three vegetation zones of the country.Fifteen ratios were generated from the quantitative variables.The data were analyzed using generalized linear model procedures followed by multiple comparisons of least-squares means and multivariate analytical methods,including canonical discrimination analysis and hierarchical ascendant classification.Each goat was then assigned to one of the three aforementioned main goat phenotypes following its morphological characteristics and according to the a priori cluster membership defined in the previous step.The Maximum Entropy algorithm was used to model the current and future distribution of the three goat phenotypes under climate change scenario using the Representative Conservation Pathways 4.5 and 8.5.Results:All linear body measurements varied among vegetation zones.In the discriminant function analysis,71%of the measured individuals were correctly classified in their vegetation zone of origin by seven measured variables and three ratios.The cluster procedure analysis revealed two groups of goats subdivided into the three main phenotypes.The modeling results showed that the currently highly favorable habitats were distributed in the South for TypeⅠ,in the North for TypeⅡ,and both South and North for TypeⅢ.However,under climate change scenarios,the favorable habitats for TypeⅠdecreased while those of TypesⅡandⅢincreased.Conclusions:The results of this study confirm the spatial variation of the goat population in Benin.The habitat suitability model can be used to support decision-making toward better management of goat genetic diversity in Benin.
