scholarly journals Variation of Vitellaria paradoxa phenophases along the north-south gradient in Mali

1970 ◽  
pp. 08-16
Author(s):  
Bokary Allaye Kelly ◽  
Mahesh Poudyal ◽  
Jean-Marc Bouvet
Keyword(s):  
Average Length ◽  
Abiotic Factors ◽  
Permanent Plots ◽  
Future Research ◽  
Vitellaria Paradoxa ◽  
The South ◽  
The North ◽  
Study Sites ◽  
Shea Tree ◽  
Research Challenge

We monitored flowering, fruiting and leafing of Vitellaria paradoxa (shea tree) along the north–south gradient in Mali (West Africa), using three study sites for a period of three years. In each site, adult shea trees were marked and monitored in permanent plots of both field and fallow stands. The chronology of phenophases and their mean length as well as flowering and fruiting were assessed. Our data revealed significant variation according to site and stand. The onset of events starts earlier in the south than in the centre or north, but the period covered by events was almost the same for all sites (3 to 6 months for flowering; 5 to 6 months for fruiting; and 2 to 4 months before full leafing).Flowering and fruiting were more regular in the south, but often as high in the north, with an almost similar trend in both fields and fallows. In the centre, flowering was also high in fields as well as in fallows, while the fruiting was medium to high. We also observed variations in the mean length of phenological events in study sites and stands. Sites in the south showed the highest average length of flowering and leafing (76 days and 44 days, respectively), while the central site showed the greatest length of mean fruiting (110 days).  We observed a significant site*stand interaction and noticeable variation over the years. Our study indicates that phenological events of shea tree could be influenced by several interacting biotic and abiotic factors. A future research challenge in shea phenology would be to discriminate these factors and thus help sustainable management of shea tree parklands.

Comparative Study of Airborne Pollen from the Northern to the Southern of Tunisia

2019 ◽  
pp. 1-8 ◽  
Author(s):  
S. Hadj Hamda ◽  
A. Ben Dhiab ◽  
M. Msallem ◽  
A. Larbi
Keyword(s):  
Crop Production ◽  
Airborne Pollen ◽  
Flowering Phenology ◽  
Plant Distribution ◽  
The South ◽  
Pollen Type ◽  
The North ◽  
Flowering Season ◽  
Pollen Types ◽  
Study Sites

Aerobiology is a multidisciplinary science dealing with biological particles in the atmosphere generated by natural activities during flowering season. Airborne pollen is now the main studied biological structure which is used as a reliable tool to study plant phenology, plant distribution changes and prediction of crop production. The main aims of this work is to determine the distribution of the different spring flowering species from the North to the South of Tunisia and to establish the pollen spectrum of three regions Mornag (North), Menzel M’hiri (Centre) and Chaal (South) in 2017. Airborne pollen data were collected using three volumetric Hirst-type spore traps placed in Mornag (36°39N; 10°16E), Menzel M’hiri (35°38N; 10°41E) and Chaal (34°34N; 10°19E) during olive flowering season. The highest pollen index was recorded in the north (Mornag, 6487.1) corresponding mainly to 18 different pollen types emitted by anemophilous species with an important presence of Cupressus pollen type having the highest contribution. Lower pollen amounts were recorded in Menzel M’hiri (5983.8) and Chaal (925.3). Olea eurpoeae was the most presented pollen type in these regions. However comparing the different study sites we can note a large distribution of some taxa from north to the south. The main common taxa were Olea europaea, Cupressaceae, Poaceae and Amaranhaceae. Their atmospheric concentrations varied also between the regions. Individual pollen index showed a sharp heterogeneity between the taxa in the same region in one hand and between the study sites in the other hand, thus a statistical analysis was performed to define the main group of taxa according to their individual pollen index. Flowering phenology of the main common taxa was also established.

scholarly journals Archaeology of the Gyranda region, Dawson River, central Queensland

1987 ◽  
Vol 4 ◽  
pp. 96-114 ◽  
Author(s):  
M.J. Morwood ◽  
L. Godwin
Keyword(s):  
Water Resources ◽  
Environmental Impact ◽  
Future Research ◽  
Impact Study ◽  
The South ◽  
The West ◽  
The North ◽  
Environmental Impact Study

This paper presents the results of survey and excavation in the upper Dawson area of the Central Queensland Sandstone Belt, a sandstone-dominated environment bounded by the townships of Banana in the east, Blackall in the west, Springsure in the north and Injune in the south, and which includes the Central Queensland Highlands (Walsh 1984:1). The work was undertaken as part of the environmental impact study for the Gyranda Weir commissioned by Cameron McNamara for the Queensland Water Resources Commission (Morwood 1985, 1986; Godwin 1985). However, the results of the study, and the potential of the area for future research, have a wider interest.

scholarly journals A SHEA BUTTER RICH IN TOCOPHEROLS (VITAMIN E) AT THE DOGON PLATEAU AND SENO BANKASS IN MALI (WEST AFRICA)

2018 ◽  
Author(s):  
Bokary Allaye Kelly ◽  
Fabrice Davrieux ◽  
Jean-Marc Bouvet
Keyword(s):  
Vitamin E ◽  
Nutritional Value ◽  
Forest Tree ◽  
Tocopherol Content ◽  
Rural Populations ◽  
Shea Butter ◽  
Vitellaria Paradoxa ◽  
Chocolate Industry ◽  
Study Sites ◽  
Shea Tree

Vitellaria paradoxa, a forest tree species plays an important role for rural populations in Mali. The kernel is rich in fat, fatty acids and tocopherols and the butter extrated from the kernel is used in many African kitchens, in pharmacology, cosmetics, local traditional medicine and as Chocolate Butter Equivalent (CBE) in chocolate industry. A consortium funded by the Europena Union has worked on several aspects of shea tree including chemical characterisation of shea butter. In Mali, one of the project partners, five sites were selected, fruits were collected from selected shea trees and sent to Montpellier for chemical analyses assessing among other variables the tocopherol content of the shea butter using liquid chromatography (HPLC). Results of this study shown that shea butter from the Dogon Plateau and the Seno Bankass is richer in tocopherols (Vitamin E) compared to other study sites. Sites were found significantly different for tocopherols content all together as well as for each type of tocopherol. The richness of shea butter from the Dogon Plateau and the Seno Bankass in tocopherols confers to it an important nutritional value for the good healf of rural populations of this zone, shea butter being the main source of fat for cooking in this area.

scholarly journals Parkia biglobosa (Nere)-A threatened useful tree species: Directory of sanitary constraints according to north-south climatic gradient in Mali

2020 ◽  
pp. 132-137
Author(s):  
Bokary Allaye Kelly ◽  
Amadou Malé Kouyaté
Keyword(s):  
Natural Regeneration ◽  
Abiotic Factors ◽  
Distribution Area ◽  
Permanent Plots ◽  
Climatic Gradient ◽  
Human Beings ◽  
Parkia Biglobosa ◽  
The North ◽  
Adult Trees ◽  
Wood Boring

Parkia biglobosa, a multi-purposes species offers food, medicine and income to rural populations. This species is facing several constraints mainly aged populations, weak natural regeneration, and reduction of tree densities. A study, was undertaken in three sites from three agro-climatic zones according to the north-south climatic gradient in southern Mali, to assess dendrometric characteristics of Parkia biglobosa trees. Permanent plots of 0.25 ha each were installed in fields and fallows with three replications in each stand within each site. Adult trees in the plots were monitored, measured and also assessed for sanitary constraints. Several sanitary constraints were encountered and classified into six categories (from attacks on trunks and gross branches to damages on fruits and general attacks, infestations and damages due to wood-boring insects, human beings and other abiotic factors). Damages like those with symptoms of dieback or staghead disease pose a serious threat for production, productivity and survival of the species. Concrete actions are necessary like sanitary diagnostic at the level of the distribution area of the species in Mali, followed by identifying real cause of damages and seeking for appropriate solutions, sensitizing and training farmers, implementing a national program of regeneration of the species by planting and/or by promoting Assisted Natural Regeneration (ANR) approach.

scholarly journals Hybrid data-model-based mapping of soil thickness in a mountainous watershed

2021 ◽  
Author(s):  
Qina Yan ◽  
Haruko Wainwright ◽  
Baptiste Dafflon ◽  
Sebastian Uhlemann ◽  
Carl I. Steefel ◽  
...  
Keyword(s):  
Hybrid Model ◽  
Spatial Resolution ◽  
Soil Layer ◽  
The South ◽  
Soil Thickness ◽  
The North ◽  
Soil Erosion Rate ◽  
East River ◽  
Thickness Prediction ◽  
Study Sites

Abstract. Soil thickness plays a central role in the interactions between vegetation, soils, and topography where it controls the retention and release of water, carbon, nitrogen, and metals. However, mapping soil thickness, here defined as the mobile regolith layer, at high spatial resolution remains challenging. Here, we develop a hybrid model that combines a process-based model and empirical relationships to estimate the spatial heterogeneity of soil thickness with fine spatial resolution (0.5 m). We apply this model to two examples of hillslopes (south-facing and north-facing, respectively) in the East River Watershed in Colorado that validates the effectiveness of the model. Two independent measurement methods – auger and cone penetrometer – are used to sample soil thickness at 78 locations to calibrate the local value of unconstrained parameters within the hybrid model. Sensitivity analysis using the hybrid model reveals that the diffusion coefficient used in hillslope diffusion modelling has the largest sensitivity among all input parameters. In addition, our results from both sampling and modeling show that, in general, the north-facing hillslope has a deeper soil layer than the south-facing hillslope. By comparing the soil thickness estimated between a machine learning approach and this hybrid model, the hybrid model provides higher accuracy and requires less sampling data. Modeling results further reveal that the south-facing hillslope has a slightly faster surface soil erosion rate and soil production rate than the north-facing hillslope, which suggests that the relatively less dense vegetation cover and drier surface soils on the south-facing slopes may influence soil characteristics. With only seven parameters for calibration, this hybrid model can provide a realistic soil thickness map at other study sites by with a relatively small amount of sampling dataset. Integrating process-based modeling and statistical analysis not only provides a thorough understanding of the fundamental mechanisms for soil thickness prediction, but integrates the strengths of both statistical approaches and process-based modeling approaches.

Antarctic studies of the coupled ionosphere-m agnetosphere system

1989 ◽  
Vol 328 (1598) ◽  
pp. 271-287 ◽  
Keyword(s):  
Solar Wind ◽  
Polar Region ◽  
Experimental Methods ◽  
Future Research ◽  
The South ◽  
Valuable Contribution ◽  
Longitudinal Structure ◽  
The North ◽  
High Latitude Ionosphere ◽  
Per Se

The southern polar region offers many significant advantages over its northern counterpart for studies of the interactions of the solar wind, magnetosphere, ionosphere and thermosphere. These mainly arise from the much wider separation of the geographic and geomagnetic poles in the south compared with the north. These displacements lead to hemispheric asymmetries and to considerable longitudinal structure in the high-latitude ionosphere and magnetosphere, which is particularly striking in the south. Examples of these effects are given. In addition, observations of geospace from Antarctica have made a valuable contribution per se . Suitable illustrations are provided from invariant latitude ca . 45° to the invariant pole. Possible areas for future research, and the experimental methods that are likely to be used to overcome the logistical difficulties, are discussed.

The Marlborough Mound, Wiltshire. A Further Neolithic Monumental Mound by the River Kennet

2013 ◽  
Vol 79 ◽  
pp. 137-163 ◽  
Author(s):  
Jim Leary ◽  
Matthew Canti ◽  
David Field ◽  
Peter Fowler ◽  
Peter Marshall ◽  
...  
Keyword(s):  
Future Research ◽  
Small Scale ◽  
Main Body ◽  
Soil Cores ◽  
Flood Events ◽  
The South ◽  
Late Neolithic ◽  
Radiocarbon Dates ◽  
North East ◽  
The North

Recent radiocarbon dates obtained from two soil cores taken through the Marlborough Castle mound, Wiltshire, show the main body of it to be a contemporaneous monument to Silbury Hill, dating to the second half of the 3rd millennium cal bc. In light of these dates, this paper considers the sequence identified within the cores, which includes two possible flood events early in the construction of the mound. It also describes four cores taken through the surrounding ditch, as well as small-scale work to the north-east of the mound. The topographic location of the mound in a low-lying area and close to rivers and springs is discussed, and the potential for Late Neolithic sites nearby is set out, with the land to the south of the mound identified as an area for future research. The paper ends with the prospect that other apparent mottes in Wiltshire and beyond may well also have prehistoric origins

Understanding the Roots of War

2018 ◽  
Author(s):  
Paul D. Escott
Keyword(s):  
African Americans ◽  
Future Research ◽  
New Work ◽  
Economic Perspective ◽  
The South ◽  
The North ◽  
Sectional Conflict

This chapter focuses on the sectional conflict leading to war. It reviews changing interpretive approaches before focusing on new work that often takes a global or Atlantic and primarily economic perspective. It raises many questions that may usefully inspire future research. The South, the North, and the “middle” or “border” third of the nation receive attention, as do African Americans and popular attitudes toward the nation.

The Thames as a Barrier in the Eighteenth Century

2018 ◽  
pp. 26-46
Author(s):  
Derek Morris ◽  
Ken Cozens
Keyword(s):  
Eighteenth Century ◽  
Future Research ◽  
The South ◽  
Tower Of London ◽  
Migration Patterns ◽  
Major Barrier ◽  
Insurance Policies ◽  
The North ◽  
Business Opportunities ◽  
North Bank

Analysis of marriage registers, apprentice records, wills and insurance policies demonstrates that in the eighteenth century, the Thames, downstream from the Tower of London, was a major barrier to the development of strong business and marriage links between the residents on the north bank in Stepney, and those on the south bank in Surrey and Kent. Possible reasons for our findings are examined in the context of London's growth, migration patterns and business opportunities. The importance of Sun Fire Office insurance policies, in examining personal and commercial links between places far apart is emphasised. Suggestions are made for future research.

scholarly journals Infection Levels of the Microsporidium Larssoniella duplicati in Populations of the Invasive Bark Beetle Ips duplicatus: From Native to New Outbreak Areas

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 131 ◽  
Author(s):  
Soňa Zimová ◽  
Karolina Resnerová ◽  
Hana Vanická ◽  
Jakub Horák ◽  
Jiří Trombik ◽  
...  
Keyword(s):  
Picea Abies ◽  
Bark Beetle ◽  
The South ◽  
Infection Level ◽  
The North ◽  
Ips Duplicatus ◽  
Specific Pathogen ◽  
Outbreak Areas ◽  
Study Sites ◽  
A Site

The microsporidium Larssoniella duplicati (Weiser, Holuša, Žižka, 2006) is a specific pathogen of the bark beetle Ips duplicatus (C.R. Sahlberg, 1836), which is a serious pest of Norway spruce (Picea abies (L.) H. Karst) in Europe. From 2011 to 2016, infection levels of L. duplicati and other pathogens in I. duplicatus populations were assessed along a gradient, ranging from areas in the north, where the beetle is native, to areas in the south, where the beetle has only recently invaded. The 21 study sites ranged in altitude from 229 to 1009 m a.s.l. We found that pathogen infection levels in I. duplicatus populations decreased from the native areas in the north to the new areas of beetle expansion in the south. We also found that pathogen level increased with altitude. The L. duplicati infection levels were not associated with the infection levels of other beetle natural enemies. The infection level decreased with the length of time of beetle establishment in an area. The infection level increased with the number of beetles trapped and dissected at a site.

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