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Lipid concentration and composition in xylem sap of woody angiosperms from a tropical savanna and a seasonal rainforest
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作者 Ling-Bo Huang Xinyi Guan +3 位作者 Amy Ny Aina Aritsara Jun-Jie Zhu Steven Jansen Kun-Fang Cao 《Plant Diversity》 SCIE CAS CSCD 2024年第1期126-133,共8页
Lipids may play an important role in preventing gas embolisms by coating nanobubbles in xylem sap.Few studies on xylem sap lipids have been reported for temperate plants,and it remain unclear whether sap lipids have a... Lipids may play an important role in preventing gas embolisms by coating nanobubbles in xylem sap.Few studies on xylem sap lipids have been reported for temperate plants,and it remain unclear whether sap lipids have adaptational significance in tropical plants.In this study,we quantify the lipid composition of xylem sap for angiosperm species from a tropical savanna(seven species)and a seasonal rainforest(five species)using mass spectrometry.We found that all twelve species studied contained lipids in their xylem sap,including galactolipids,phospholipids and triacylglycerol,with a total lipid concentration ranging from 0.09 to 0.26 nmol/L.There was no difference in lipid concentration or composition between plants from the two sites,and the lipid concentration was negatively related to species’open vessel volume.Furthermore,savanna species showed little variation in lipid composition between the dry and the rainy season.These results support the hypothesis that xylem sap lipids are derived from the cytoplasm of individual conduit cells,remain trapped inside individual conduits,and undergo few changes in composition over consecutive seasons.A xylem sap lipidomic data set,which includes 12 tropical tree species from this study and 11 temperate tree species from literature,revealed no phylogenetic signals in lipid composition for these species.This study fills a knowledge gap in the lipid content of xylem sap in tropical trees and provides additional support for their common distribution in xylem sap of woody angiosperms.It appears that xylem sap lipids have no adaptive significance. 展开更多
关键词 Xylem sap LIPIDS Tropical savanna Tropical rainforest Vessels
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Leaf habit differentiation explains trait tradeoffs across savanna woody plants
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作者 Yangsiding Wang Da Yang +6 位作者 German Vargas G. Guangyou Hao Jennifer S.Powers Yan Ke Qin Wang Yunbing Zhang Jiaolin Zhang 《Forest Ecosystems》 SCIE CSCD 2024年第3期287-295,共9页
Identifying how leaf habit subdivisions link to the fast–slow and avoidance–tolerance trait tradeoffs can provide new insight into divergence in ecophysiological strategies among plant functional groups. Here, we te... Identifying how leaf habit subdivisions link to the fast–slow and avoidance–tolerance trait tradeoffs can provide new insight into divergence in ecophysiological strategies among plant functional groups. Here, we tested a hypothesis that the differentiation across deciduous, semi-deciduous and evergreen woody species contributes to physiological trait tradeoffs in a dry-hot valley savanna. We investigated 11 photosynthetic, morphological and hydraulic traits of 24 species including 8 deciduous, 10 semi-deciduous and 6 evergreen species. Deciduous species were grouped in the fast and avoidance side associated with high values of maximum photosynthetic rates,stomatal conductance and leaf size, while evergreen species were grouped in the slow and tolerance side associated with high photosynthetic water use efficiency, leaf mass per area, sapwood density, Huber value, leaf water potential at turgor loss point and water potential causing 50% loss of stem hydraulic conductance. Semideciduous species generally had intermediate trait values and represented different physiological characteristics when compared to deciduous and evergreen species. The physiological trait tradeoffs showed a close linkage to the differentiation of these three leaf habits. Our findings clearly reveal trait tradeoffs related to fast–slow and avoidance–tolerance strategies among diverse savanna plants, suggesting a syndrome in multiple ecophysiology strategies across different leaf habits. 展开更多
关键词 Dry-hot habitat Gas exchange Hydraulics PHENOLOGY Tolerance Valley savanna
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Yield and Yield Components of Bread Wheat as Influenced by Water Stress, Sowing Date and Cultivar in Sokoto, Sudan Savannah, Nigeria 被引量:1
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作者 Mohammed Bello Sokoto Agit Singh 《American Journal of Plant Sciences》 2013年第12期122-130,共9页
Field experiments were conducted during 2009/10 and 2010/2011 dry seasons at the Fadama Teaching and Research Farm of the Usmanu Danfodiyo University, Sokoto, in the Sudan Savanna ecological zone of Nigeria (latitude ... Field experiments were conducted during 2009/10 and 2010/2011 dry seasons at the Fadama Teaching and Research Farm of the Usmanu Danfodiyo University, Sokoto, in the Sudan Savanna ecological zone of Nigeria (latitude 13°01'N;longitude 5°15'E, altitude of 350 m above sea level) to study the effect of water stress, sowing date and cultivar on yield and yield components of wheat (Triticum aestivum L.). The treatments consisted of factorial combination of water stress at three critical growth stages which was imposed by withholding water at tillering, flowering, grain filling and control (no stress), four sowing dates (21st November, 5th December, 19th December and 2nd January) and two bread wheat cultivar (Star 11 TR 77173/SLM and Kuaz/Weaver), laid out in a split-plot design with three replications. Water stress and date of sowing were assigned to the main-plot, while variety was assigned to the sub-plots. Result revealed that water stress at tillering significantly reduced spike length and grains per spike. Whereas, water stress at flowering and grain filling significantly reduced 1000-grain weight, grain yield and harvest index. Results also indicated significant (P st November and 5th December and lowest at 19th December and 2nd January, therefore wheat should be sown in November or at least first week of December in this area and other area with similar climate. Variety had significant effect on spike per m-2, grain yield and harvest index. Water stress at flowering and grain filling should be avoided as they are the most critical growth stages in yield determination in wheat, because plants cannot recover, while delay in sowing resulted in reduction in yield and yield components. Star II TR 77173/SLM is therefore recommended for the area. 展开更多
关键词 YIELD YIELD Components Bread Wheat Water Stress SOWING Date CULTIVAR SUDAN savanna
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Phytochemical Analysis and Antifungal Activity of Extracts from Leaves and Fruit Residues of Brazilian Savanna Plants Aiming Its Use as Safe Fungicides 被引量:1
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作者 Caroline Alves Breda Alessandra Marcon Gasperini +4 位作者 Vera Lucia Garcia Karin Maia Monteiro Giovana Anceski Bataglion Marcos Nogueira Eberlin Marta Cristina Teixeira Duarte 《Natural Products and Bioprospecting》 CAS 2016年第4期195-204,共10页
The increasing demand for safe food without preservatives or pesticides residues has encouraged several studies on natural products with antifungal activity and low toxicity.In this study,ethanolic extracts from leave... The increasing demand for safe food without preservatives or pesticides residues has encouraged several studies on natural products with antifungal activity and low toxicity.In this study,ethanolic extracts from leaves and fruit residues(peel and seeds)of three Brazilian savanna species(Acrocomia aculeata,Campomanesia adamantium and Caryocar brasiliense)were evaluated against phytopathogenic fungi.Additionally,the most active extract was chemically characterized by ESI-MS and its oral acute toxicity was evaluated.Extracts from C.brasiliense(pequi)peel and leaves were active against Alternaria alternata,Alternaria solani and Venturia pirina with minimal inhibitory concentrations between 350 and 1000 lg/mL.When incorporated in solid media,these extracts extended the lag phase of A.alternata and A.solani and reduced the growth rate of A.solani.Pequi peel extract showed better antifungal activity and their ESI-MS analysis revealed the presence of substances widely reported as antifungal such as gallic acid,quinic acid,ellagic acid,glucogalin and corilagin.The oral acute toxicity was relatively low,being considered safe for use as a potential natural fungicide. 展开更多
关键词 Brazilian savanna fruits RESIDUES Natural fungicides PHYTOPATHOGENS
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Baru almonds from different regions of the Brazilian Savanna: Implications on physical and nutritional characteristics 被引量:1
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作者 Ludmila P. Czeder Daniela C. Fernandes +1 位作者 Jullyana B. Freitas Maria Margareth V. Naves 《Agricultural Sciences》 2012年第5期745-754,共10页
While some reports show that physical characteristics of the baru fruits (Dipteryx alata Vog.) differ within and among the Brazilian Savanna regions, a study shows that there are differences in the nutritional composi... While some reports show that physical characteristics of the baru fruits (Dipteryx alata Vog.) differ within and among the Brazilian Savanna regions, a study shows that there are differences in the nutritional composition of baru almonds from different trees from the same Savanna area. It is unknown, however, whether the Savanna’s region influences the nutritional quality of this native almond. Thus, we evaluated the influence of East, Southeast and West regions of the Brazilian Savanna on physical characteristics, nutrient composition and protein quality of the baru almond. Chemical composition and amino acid profile were analyzed, and Amino Acid Score (AAS), Net Protein Ratio (NPR), and Protein Digestibility–Corrected Amino Acid Score (PDCAAS) were estimated. The physical characteristics significantly differed within but not among regions. The protein (310 g kg-1), lipid (410 g·kg-1), fiber (120 g·kg-1) and calcium (1,300 mg·kg-1) contents of baru almonds were high, with significant differences among regions for insoluble fiber content (94.3 - 128.3 g·kg-1) and amino acid profile (AAS = 77% - 89%). The relative NPR (RNPR) values were similar among regions (mean value of RNPR = 71%), and the PDCAAS values ranged from 65 to 73%. The region of the Brazilian Savanna influences the fiber and amino acid profiles, but not the total content of nutrients, the protein quality and the physical characteristics of the native baru almonds. The baru almond is a potential food as source of complementary protein for healthy diets and as a nutritious raw material for various food systems. 展开更多
关键词 Dipteryx Alata Vog. EDIBLE SEEDS Nuts savanna Nutritive Value AMINO ACIDS
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Rice Yield and Yield Components as Influenced by Phosphorus and Nitrogen Application Rates in the Moist Savanna of West Africa 被引量:1
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作者 Christopher J. Okonji Kehinde A. Okeleye +4 位作者 Sylvester O. Oikeh Sunday G. Aderibigbe Francis E. Nwilene Olupomi Ajayi Akeem A. Oyekanmi 《Journal of Agricultural Science and Technology(B)》 2012年第12期1214-1223,共10页
A two-year field experiment was conducted to evaluate the influence of nitrogen (0, 30, 60, and 120 kg N ha^-1) and phosphorus (0, 30, and 60 kg P2O5 ha^-1) application on grain yield and yield components of five ... A two-year field experiment was conducted to evaluate the influence of nitrogen (0, 30, 60, and 120 kg N ha^-1) and phosphorus (0, 30, and 60 kg P2O5 ha^-1) application on grain yield and yield components of five New Rice for Africa (NERICA) cultivars, their parents, and a check on a degraded soil in the moist savanna of Nigeria. Nerica 14 recorded the highest grain yield of 1.3 mg halcompared to the other NERICA cultivars. It also produced significantly (P 〈 0.05) longer panicles (19.24 cm), higher sink capacity as determined by thousand-kernel weight (30.3 g), and a higher potential for partitioning photosynthates (45.15%) into grains than the other cultivars. N × P interaction effect on grain yield was significant (P 〈 0.05) with moderate P (60 kg P2O5 ha^1) and moderate N (60 kg N ha^-1) resulting in optimum grain yield (1.7 mg ha^-1). Thus, moderate N and P were recommended for the production of NERICA varieties in low-input smallholder upland rice production systems of the moist savanna of Nigeria. 展开更多
关键词 Moist savanna NERICA rice nitrogen Oryza sativa PHOSPHORUS upland.
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Integrating Remote Sensing and Geostatistics to Model Woody Density Distribution in a Tropical Savanna
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作者 Clement Adjorlolo Onisimo Mutanga 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期280-280,共1页
remote sensing of woody vegetation in savannas has been inhibited by its complex stand structure and abundant vegetation species.An understanding of the distribution and spatial variation in savanna vegetation is crit... remote sensing of woody vegetation in savannas has been inhibited by its complex stand structure and abundant vegetation species.An understanding of the distribution and spatial variation in savanna vegetation is critical for making timely assessments of the ecosystem conditions.This study investigated the possibility of improving the prediction of woody vegetation in tropical savannas using an approach that integrates spatial statistics and remote sensing. 展开更多
关键词 WOODY COVER density spatial distribution savanna RANGELANDS REMOTE sensing GEOSTATISTICS
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Tree-ring:a suitable implement for spatial and temporal fire distribution analysis in savanna woodland and dry forest
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作者 Franck Sinsin Romain GlèlèKaka? +1 位作者 Bettina Orthmann Brice Sinsin 《Journal of Forestry Research》 SCIE CAS CSCD 2015年第2期435-446,共12页
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
关键词 Fire ecology TREE-RINGS savanna woodland Dry forest Conservation strategies
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New patterns of the tree beta diversity and its determinants in the largest savanna and wetland biomes of South America
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作者 Karla J.P.Silva-Souza Maíra G.Pivato +2 位作者 Vinícius C.Silva Ricardo F.Haidar Alexandre F.Souza 《Plant Diversity》 SCIE CAS CSCD 2023年第4期369-384,共16页
Clear and data-driven bioregionalizations can provide a framework to test hypotheses and base biodiversity conservation.Here we used occurrence and abundance data in combination with objective analytical methods to pr... Clear and data-driven bioregionalizations can provide a framework to test hypotheses and base biodiversity conservation.Here we used occurrence and abundance data in combination with objective analytical methods to propose two bioregionalization schemes for tree species of the Cerrado and the Pantanal in South America.We also evaluated the contribution of three sets of determinants of the occurrence-and abundance-based subregions.We compiled data on tree species composition from 894 local assemblages based on species occurrences,and from 658 local assemblages based on species abundances.We used an unconstrained community-level modelling approach and clustering techniques to identify and map tree subregions for the occurrence and the abundance data sets,separately.Hierarchical clustering analyses were conducted to investigate floristic affinities between the subregions and to map broader floristic regions.We used multinomial logistic regression models,deviance partitioning,and rank-sum tests to assess the main subregion correlates.We identified 18 occurrence-and four abundance-based subregions in the Cerrado-Pantanal.The hierarchical classifications grouped the occurrence-based subregions into nine floristic zones and abundance-based subregions into two broad floristic zones.Variation in subregions were explained mainly by environmental factors and spatial structure in both occurrence and abundance data sets.The occurrence-and abundance-based subregions are complementary approaches to disentangle macroecological patterns and to plan conservation efforts in the Cerrado and the Pantanal.Our findings based on occurrence data revealed more complex and interdigitated boundaries between subregions of tree species than previously reported.The environment,historical stability,and human effects act in a synergetic way on the distribution of the subregions.Finally,the relevance of contemporary environmental factors to the subregion patterns we found alert us to the profound impact global warming may have on the spatial organization of the Cerrado-Pantanal tree flora. 展开更多
关键词 CERRADO PANTANAL savanna Biogeographical regionalization Biodiversity hotspot South America
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Accuracy of common stem volume formulae using terrestrial photogrammetric point clouds:a case study with savanna trees in Benin
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作者 Hospice A.Akpo Gilbert Atindogbe +3 位作者 Maxwell C.Obiakara Arios B.Adjinanoukon Madai Gbedolo Noel H.Fonton 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第6期2415-2422,共8页
Recent applications of digital photogrammetry in forestry have highlighted its utility as a viable mensuration technique.However,in tropical regions little research has been done on the accuracy of this approach for s... Recent applications of digital photogrammetry in forestry have highlighted its utility as a viable mensuration technique.However,in tropical regions little research has been done on the accuracy of this approach for stem volume calculation.In this study,the performance of Structure from Motion photogrammetry for estimating individual tree stem volume in relation to traditional approaches was evaluated.We selected 30 trees from five savanna species growing at the periphery of the W National Park in northern Benin and measured their circumferences at different heights using traditional tape and clinometer.Stem volumes of sample trees were estimated from the measured circumferences using nine volumetric formulae for solids of revolution,including cylinder,cone,paraboloid,neiloid and their respective fustrums.Each tree was photographed and stem volume determined using a taper function derived from tri-dimensional stem models.This reference volume was compared with the results of formulaic estimations.Tree stem profiles were further decomposed into different portions,approximately corresponding to the stump,butt logs and logs,and the suitability of each solid of revolution was assessed for simulating the resulting shapes.Stem volumes calculated using the fustrums of paraboloid and neiloid formulae were the closest to reference volumes with a bias and root mean square error of 8.0%and 24.4%,respectively.Stems closely resembled fustrums of a paraboloid and a neiloid.Individual stem portions assumed different solids as follows:fustrums of paraboloid and neiloid were more prevalent from the stump to breast height,while a paraboloid closely matched stem shapes beyond this point.Therefore,a more accurate stem volumetric estimate was attained when stems were considered as a composite of at least three geometric solids. 展开更多
关键词 Structure from motion photogrammetry Point cloud data Stem volume savanna species BENIN
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Exploring tree diversity and stand structure of savanna woodlands in southeastern Sudan
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作者 Ahmed M M HASOBA Ahmed A H SIDDIG Yousif E YAGOUB 《Journal of Arid Land》 SCIE CSCD 2020年第4期609-617,共9页
Savanna woodlands in Sudan host great biodiversity, provide a plethora of ecosystem goods and services to local communities, and sustain numerous ecological functions. Although the importance of the Acacia trees in th... Savanna woodlands in Sudan host great biodiversity, provide a plethora of ecosystem goods and services to local communities, and sustain numerous ecological functions. Although the importance of the Acacia trees in these areas is well known, up-to-date information about these woodlands' diversity is limited and changes in their woody vegetation composition, density, diversity and relative frequency are not monitored over time. This study explored tree diversity and stand stage structure in Nuara Reserved Forest, a typical savanna woodland ecosystem in southeastern Sudan. A total of 638 circular sample plots(1000 m^2 for each) were established using a systematic sampling grid method. The distance between plots was 200 m. In each plot, all living trees with diameter at breast height(DBH) ≥5.00 cm were identified and counted, and their DBH values were recorded. From these data, tree composition, diversity, density and stage structure were assessed. There were 12,259 individual trees representing four species(Acacia seyal, Balanites aegyptiaca, Acacia Senegal and Acacia mellifera) that belong to two families. The dominant species was Acacia seyal. Average tree density was 191 trees/hm^2 and the Shannon-Weiner index for trees diversity was 0.204. Overall, young trees comprised 86.30% of the forest. The state of tree richness and density in the study area was low compared to other similar environments in the region and around the world. We recommended adoption of a proper management system that includes monitoring of woody vegetation diversity in this forest, and management actions to enhance tree diversity and sustain ecosystem services to local communities. In addition to care for the dominant Acacia seyal stands, more attention and conservation should be devoted to reestablishing Acacia senegal and Acacia mellifera trees because of their high ecological and economic values for local communities. 展开更多
关键词 species diversity stand structure savanna woodland ecosystem forest monitoring forest management ecosystem services Nuara Reserved Forest
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Intraspecific trait variation of woody species reduced in a savanna community,southwest China
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作者 Lubing Liu Jie Yang +1 位作者 Min Cao Qinghai Song 《Plant Diversity》 SCIE CAS CSCD 2022年第2期163-169,共7页
Plants deploy various ecological strategies in response to environmental heterogeneity.In many forest ecosystems,plants have been reported to have notable inter-and intra-specific trait variation,as well as clear phyl... Plants deploy various ecological strategies in response to environmental heterogeneity.In many forest ecosystems,plants have been reported to have notable inter-and intra-specific trait variation,as well as clear phylogenetic signals,indicating that these species possess a degree of phenotypic plasticity to cope with habitat variation in the community.Savanna communities,however,grow in an open canopy structure and exhibit little species diversification,likely as a result of strong environmental stress.In this study,we hypothesized that the phylogenetic signals of savanna species would be weak,the intraspecific trait variation(ITV)would be low,and the contribution of intraspecific variation to total trait variance would be reduced,owing to low species richness,multiple stresses and relatively homogenous community structure.To test these hypotheses,we sampled dominant woody species in a dry-hot savanna in southwestern China,focusing on leaf traits related to adaptability of plants to harsh conditions(yearround intense radiation,low soil fertility and seasonal droughts).We found weak phylogenetic signals in leaf traits and low ITV(at both individual and canopy-layer levels).Intraspecific variation(including leaf-,layer-and individual-scales)contributed little to the total trait variance,whereas interspecific variation and variation in leaf phenology explained substantial variance.Our study suggests that intraspecific trait variation is reduced in savanna community.Furthermore,our findings indicate that classifying species by leaf phenology may help better understand how species coexist under similar habitats with strong stresses. 展开更多
关键词 Phylogenetic signal savanna Intraspecific trait variation(ITV) Leaf phenology Coexistence
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The Fluxes of Organic C and N, and Microbial Biomass and Maize Yield in an Organically Manured Ultisol of the Guinea Savanna Agroecological Zone of Nigeria
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作者 S. O. Agele S. O. Ojeniyi S. K. Ogundare 《Journal of Agricultural Chemistry and Environment》 2015年第4期83-95,共13页
Field experiments were conducted to evaluate the effects of integrated use of agricultural wastes and a compound mineral fertilizer on the fluxes of soil nutrients. Agricultural wastes applied were: livestock manure (... Field experiments were conducted to evaluate the effects of integrated use of agricultural wastes and a compound mineral fertilizer on the fluxes of soil nutrients. Agricultural wastes applied were: livestock manure (cow dung and poultry litter), shoots of Chromolaena odorata and Parkia biglosa (locust bean), Neem (Azadiracta inidca) seed powder/cake and melon shell. These materials were applied at zero (control), 100% (i.e. organic wastes applied at the recommended rates of 10 t/ha) and 70% of their recommended rates plus 30% of the recommended rate of the mineral fertilizer (NPK: 400 Kg/ha). Average values of soil organic carbon (SOC) were 1.94, 1.68, 1.36 and 1.38 for organic wastes alone, organic waste plus mineral fertilizer (NPK) and unamended control. Mineral N ( N plus N) pools were relatively high at 30 and 60 days after planting, and were significantly higher for organically amended soils (550) and wastes applied at reduced rates combined with 120 kg/ha mineral NPK (470) than the unamended control (277). Across sampling dates, SOC values were the highest in poultry manure and neem seed cake. The values of N plus exchangeable N which constitutes plant available nitrogen (PAN) were significantly higher for organically amended soils and wastes applied at reduced rates combined with 120 kg/ha mineral NPK than the unamended control. The % C microbial to C organic ratio was higher in organically amended soils. The temporal profile of SOC, NH4-N and NO3-N showed declines with time, the relationship was linear for SOC (Y = 0.18x + 1.07;R2 = 0.34), by a power function for N (Y = 48.084x-1.79;R2 = 0.91) and a polynomial function for NH4-N (Y = -28.75x + 130.65x - 57.25;R2 = 0.61). The time dynamics of microbial population (cfu) followed trends obtained for SOC. 展开更多
关键词 Organic Carbon Mineral N Microbial Biomass savanna ULTISOL TROPICS
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Influence of phosphorus on the performance of cowpea (Vigna unguiculata (L) Walp.) varieties in the Sudan savanna of Nigeria
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作者 A. Singh A. L. Baoule +6 位作者 H. G Ahmed A. U. Dikko U. Aliyu M. B. Sokoto J. Alhassan M. Musa B. Haliru 《Agricultural Sciences》 2011年第3期313-317,共5页
Savanna regions of Nigeria are deficient in nitrogen and phosphorus, which retard the growth and yield of crops. Therefore, a study was conducted in the wet season of 2006 at the Dry Land Teaching and Research Farm of... Savanna regions of Nigeria are deficient in nitrogen and phosphorus, which retard the growth and yield of crops. Therefore, a study was conducted in the wet season of 2006 at the Dry Land Teaching and Research Farm of Usmanu Danfodiyo University, Sokoto to evaluate the effect of phosphorus on the growth and yield of two cowpea varieties sourced from Republic of Niger. Treatment consisted of four (4) rates of phosphorus (0, 20, 40, 60 kg.ha–1) factorialy combined with (2) varieties of cowpea (kvx303096G and TN5-78) and laid out in a randomized complete block design (RCBD) replicated three (3) times. Results showed significant response to applied P on pods per plant, grain and stover yield and 100-seed weight with highest response to the application of 60 kg.P.ha–1. From this study it can be concluded that KVX303096G and TN5-78 could both be sown under Sokoto condition to obtain reasonable yield of about 1 t.ha–1 of grain and 1.6 t.ha–1 of stover. Irrespective of the varieties, application of 60 kg P2O5 ha–1 could be recommended for higher yield of cowpea (1.4 t.ha–1) relative to 0 kg.P.ha–1 that yielded 1.0 t.ha–1. 展开更多
关键词 COWPEA [Vigna Unguiculata (L.) Walp.] PHOSPHORUS SUDAN savanna NIGERIA
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NDVI-Derived Vegetation Trends and Driving Factors in West African Sudanian Savanna
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作者 Benewindé J.-B. Zoungrana Kangbeni Dimobé 《American Journal of Plant Sciences》 2023年第10期1130-1145,共16页
The Sudanian savanna is a key vegetation biome in West Africa providing food and vital ecosystem services. Recently, it has been reported alarming vegetation loss in this biome, calling for more investigation, relevan... The Sudanian savanna is a key vegetation biome in West Africa providing food and vital ecosystem services. Recently, it has been reported alarming vegetation loss in this biome, calling for more investigation, relevant to tackle land degradation and ensure food security. However, vegetation dynamics in this area remains a matter of debate, and one of the main challenges is to document consistently the underlying driving factors. This study aimed at assessing vegetation trends and driving factors from 2000 to 2022. NDVI trend, detected using the Mann-Kendall’s monotonic trend test, was used as proxy to express vegetation dynamics. In addition to the non-parametric Spearman correlation analysis, variables importance scores, derived from Random Forest (RF) classifications, were used to determine key driving factors among climatic, topographic, edaphic, accessibility and demographic factors. During 2000-2022, no significant trends largely characterised the vegetation cover of the study area. However, patterns of strong (weak) browning and strong (weak) greening affected 7.1% (10.6%) and 12.8% (19.1%) of the study area respectively. According to the driving factors analysis, the observed vegetation trends were mainly driven by rainfall dynamics (trend and mean annual), population growth and anthropogenic activities. The results of this study can support the development of efficient strategies for safeguarding vegetation cover in the Sudanian savanna of Burkina Faso. 展开更多
关键词 Vegetation Trends NDVI Sudanian savanna Burkina Faso West Africa
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Farmers' Perceptions of Soil Fertility Status in the Savannah Zone of Centre Cameroon
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作者 Ndaka Bonguen Samuel Michel Abossolo Angue Monique +1 位作者 Bidzanga Nomo Lucien Bilong Paul 《Journal of Agricultural Science and Technology(A)》 2015年第9期723-731,共9页
In Cameroon, most farmers rely on their perceptions for fertility evaluation and choice of agricultural land units. However, because of environmental change, this knowledge is mostly disregarded. The use of farmers' ... In Cameroon, most farmers rely on their perceptions for fertility evaluation and choice of agricultural land units. However, because of environmental change, this knowledge is mostly disregarded. The use of farmers' knowledge is important for the identification of relevant information for the choice of agricultural land units. The objective of this study was to compare farmers' perceptions of soil fertility with a conventional scientific approach in two locations of the forest margin zone of Center Cameroon. Through interviews and soil analysis, this study spelled and weighed the relationships between farmers' perceptions and soil fertility status. One hundred and twenty households' heads were interviewed and 30 soil samples collected. Farmers' perceptions were used to assess the topsoil fertility status across the studied areas, while a conventional scientific approach was used to quantify soil fertility status by the means of a soil fertility index (SFI). Results showed that farmers, for soil differentiation, used color, texture, depth, drainage and vegetation. Soil' names delivered key messages for their location. Although the low overall SFI approximated by the conventional approach, farmers' perceptions could differentiate fertility levels between soils. This knowledge is relevant for the design of technical innovations in perceived fertility niches. 展开更多
关键词 Cameroon FERTILITY perception savanna soils smallholder farmers.
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Evaluation of Neem-based Compound Fertilizer for Crop Production in Samaru, Moist Savanna of Nigeria
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作者 A. A. Yusuf E. N. O. Iwuafor +3 位作者 Z. Ladan A. S. Agbaji Z. Abdulsalam H. A. Yusuf 《Journal of Agricultural Science and Technology(A)》 2011年第2X期235-243,共9页
Nutrient mining is one of the major threats facing crop production in Africa and inputs of nutrients are required to overcome this constraint. Greenhouse and field trials were conducted to investigate the effect of so... Nutrient mining is one of the major threats facing crop production in Africa and inputs of nutrients are required to overcome this constraint. Greenhouse and field trials were conducted to investigate the effect of sole and combined applications of neem-based and conventional compound (NPK 15-15-15) fertilizers on five crops. In another set of treatments, a factorial combination of the neem fertilizer and urea at 30, 60 and 90 kg N ha-1 was applied to maize, millet and sorghum in the field in a randomized complete block design. The results obtained on cowpea and soybean showed that application of 20 kg N hal from the neem-based compound fertilizer produced both grain and haulm yields that were comparable to what was obtained with the application of 30 kg N ha1 from the conventional fertilizer. Based on maize performance, combined application of neem-based and NPK in ratio 0.25:0.75 respectively gave significantly (P 〈 0.01) higher plant height, stem girth, shoot and dry weight compared to other treatment combinations. The causes of the interactions between the two fertilizer sources resulting in added benefits from their mixed rather than sole application could be attributed to improvement in phosphorus availability and other soil conditions. 展开更多
关键词 NEEM crop production FERTILIZER moist savanna.
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Impacts of climate change on the yields of leguminous crops in the Guinea Savanna agroecological zone of Ghana
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作者 Enoch YELELIERE Philip ANTWI-AGYEI Frank BAFFOUR-ATA 《Regional Sustainability》 2023年第2期139-149,共11页
The impacts of climate change on crop yields are receiving renewed interest,with focus on cereals and staple crops at the regional and national scales.Yet,the impacts of climate change on the yields of leguminous crop... The impacts of climate change on crop yields are receiving renewed interest,with focus on cereals and staple crops at the regional and national scales.Yet,the impacts of climate change on the yields of leguminous crops in the local context has not been explored.Thus,an in-depth understanding of climate change in the local context may support the design of locally relevant adaptation responses to current and future climate risks.This study examined the impacts of climate variables(annual rainfall,annual average temperature,rainfall indices(rainfall onset,rainfall cessation,and the length of rainy days),and the number of dry days)on the yields of leguminous crops(groundnuts,cowpeas,and soybeans)in the Guinea Savanna agroecological zone of Ghana during the period of 1989-2020.The data were analysed using Mann-Kendall’s trend,Sen’s slope test,correlation analysis,and Multiple Regression Analysis(MRA).The findings revealed that annual rainfall,annual average temperature,rainfall onset,rainfall cessation,and the length of rainy days,and the number of dry days all showed varied impacts on the yields of groundnuts,cowpeas,and soybeans.The trend analysis detected a marginal decrease in the amount of rainfall,rainfall onset,and the number of dry days from 1989 to 2020(P>0.050).Annual average temperature and the length of rainy days substantially varied(P<0.050)from 1989 to 2020,showing an increasing trend.The findings also showed a marked upward trend for the yields of groundnuts,cowpeas,and soybeans during 2005-2020.The climate variables analysed above increased the yields of groundnuts,cowpeas,and soybeans by 49.0%,55.0%,and 69.0%,respectively.The yields of groundnuts,cowpeas,and soybeans fluctuated with the variability of 30.0%,28.0%,and 27.0%from 2005 to 2020,respectively.The three leguminous crops under study demonstrated unpredictable yields due to the variations of annual rainfall,annual average temperature,rainfall onset,rainfall cessation,the length of rainy days,and the number of dry days,which stressed the need for agricultural diversification,changing planting dates,using improved seed variety,and irrigation to respond to climate change.The results of this study implied that climate change considerably impacts crop production in the Guinea Savanna agroecological zone of Ghana,emphasizing the urgency of locally based and farmer-induced adaptation measures for food security and resilient agricultural systems. 展开更多
关键词 Climate change Leguminous crops(groundnuts cowpeas and soybeans) Guinea savanna Annual average temperature Rainfall indices Number of dry days
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A Contribution to Pollen Rain Characterization in Forest-Savanna Mosaics of the Venezuelan Guayana and Its Use in Vegetation Reconstructions from Sedimentary Records
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作者 Leal Alejandra Bilbao Bibiana Berrío Juan Carlos 《American Journal of Plant Sciences》 2013年第7期33-52,共20页
The main results of a study of pollen representation in surface soils from different plant communities in the upland savannas of Guayana were presented. The representation of savanna herb pollen mainly belonging to th... The main results of a study of pollen representation in surface soils from different plant communities in the upland savannas of Guayana were presented. The representation of savanna herb pollen mainly belonging to the Poaceae and Cyperaceae was high in open communities such as fernlands, grasslands and Mauritia palm swamps, but decreased as vegetation structure became more closed and woody;from savanna-forest borders to secondary forests and lastly, evergreen montane forests;mimicking the gradient of vegetation openness observed in living plant communities. Thus, the proportion of savanna herb pollen in herbaceous communities: swamps, fernlands and grasslands, reached over 80% and arboreal pollen contributed less than 10%. This ratio changed in savanna-forest borders where savanna herb pollen decreased to 60% or less and the proportion of arboreal pollen rose to 30% or higher. Lastly, in forest soils, pollen abundances from trees (Dimorphandra, Protium, Schefflera), shrubs (Miconia and other Melastomataceae) and lianas contributed higher than 60% of the pollen sum, even in open gallery forests and fallows. The lack of pollen from cassava, the main crop in the forests of the region, at these sites was remarkable. The ordination of sediment samples from 4 records from the Late Holocene with respect to the soil surface samples studied, showed that the characterization of pollen rain was useful for identifying long-term compositional and structural changes in the sedimentary records, thus providing objective indicators for the interpretation of past vegetation structure. 展开更多
关键词 POLLEN Representation savanna-Forest Dynamics UPLAND Guayana GRAN Sabana POACEAE POLLEN
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Enhancing Rice Productivity and Soil Nitrogen Using Dual-Purpose Cowpea-NERICARice Sequence in Degraded Savanna
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作者 Sylvester O. Oikeh Abibu Niang +4 位作者 Robert Abaidoo Pascal Houngnandan Koichi Futakuchi Brahima Kone Amadu Toure 《Journal of Life Sciences》 2012年第11期1237-1250,共14页
ISFM (integrated soil fertility management) involving annual sequencing of dual-purpose early-maturing first crop of cowpeas with biomass incorporation before seeding second crop of early-maturing NERICA (New Rice ... ISFM (integrated soil fertility management) involving annual sequencing of dual-purpose early-maturing first crop of cowpeas with biomass incorporation before seeding second crop of early-maturing NERICA (New Rice for Africa) was evaluated to enhance rice productivity and soil-nitrogen. Five dual-purpose early-maturing cowpea cultivars and local cultivar (Katche) were seeded early in the wet season in five farmers' fields at Ouake (9046' N, 1°35′ E, highly degraded-savanna), Benin. After pod harvest, cowpea residues were minimally worked into the soil using minimum tillage with hand-hoe and seeded with early-maturing, resilient NERICA8 rice that received either 20 kg N/ha or zero-N. Cowpea grain yield averaged 0.1-0.3 Mg/ha, and mean aboveground cowpea biomass produced and recycled was 0.54-0.64 Mg/ha among best cultivars (IT97-568-11 and IT89KD-288). NERICA8 seeded after cowpea cv. IT97-568-11 and supplied with 20N gave the greatest grain yield of about 2.0 Mg/ha, accounting for 500% heavier grains than fallow-rice rotation with zero-N. Mineral-N dynamics monitored under NERICA8 in year 2 showed that previous IT97-568-11 plots had the highest mineral-N at tillering which persisted till panicle initiation stage. The adoption of an ISFM comprising annual cowpea-NERICA sequence by smallholder rice farmers could enhance productivity and improve N-supply in fragile savannas. 展开更多
关键词 Degraded savanna dual-purpose cowpea ISFM NERICA rice rice productivity soil nitrogen West Africa.
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