Geochemistry, mineral paragenesis and geothermal conditions of oreforming fluids from the Ain El Bey Cu–Fe deposit: potential occurrence of native gold and precious metal traces (North African orogenic belt, Northern Tunisia)

The Ain El Bey abandoned mine, in North-West Tunisia, fits into the geodynamic context of the European and African plate boundary. Ore deposit corresponds to veins and breccia of multiphase Cu–Fe-rich mineralization related to various hydrothermal fluid circulations. Petromineralogical studies indicate a rich mineral paragenesis with a minimum of seven mineralization phases and, at least, six pyrite generations. As is also the case for galena and native silver, native gold is observed for the first time as inclusion in quartz which opens up, thus, new perspectives for prospecting and evaluating the potential for noble metals associated with the mineralization. Scanning Electron Microscope--Energy Dispersive Spectroscopy and Transmission electron microscopy analyses show, in addition, a large incorporation of trace elements, including Ag and Au, in mineral structures such as fahlores(tetrahedrite-tennantite) and chalcopyrite ones. The mineral/mineral associations, used as geothermometers, gave estimated temperatures for the mineralizing fluids varying from 254 to 330 ℃ for phase Ⅲ, from 254 to 350 ℃ for phase Ⅳ, and from 200 to 300 ℃ for phases Ⅴ and Ⅵ. The seventh and last identified mineralization phase, marked by a deposit of native gold, reflects a drop in the mineralizing fluid’s temperature(< 200 ℃) compatible with boiling conditions. Such results open up perspectives for the development of precious metal research and the revaluation of the Cu–Fe ore deposit at the Ain El Bey abandoned mine, as well as at the surrounding areas fitting in the geodynamic framework of the Africa-Europe plate boundary.

Combining RUSLE model and the vegetation health index to unravel the relationship between soil erosion and droughts in southeastern Tunisia

Droughts and soil erosion are among the most prominent climatic driven hazards in drylands,leading to detrimental environmental impacts,such as degraded lands,deteriorated ecosystem services and biodiversity,and increased greenhouse gas emissions.In response to the current lack of studies combining drought conditions and soil erosion processes,in this study,we developed a comprehensive Geographic Information System(GIS)-based approach to assess soil erosion and droughts,thereby revealing the relationship between soil erosion and droughts under an arid climate.The vegetation condition index(VCI)and temperature condition index(TCI)derived respectively from the enhanced vegetation index(EVI)MOD13A2 and land surface temperature(LST)MOD11A2 products were combined to generate the vegetation health index(VHI).The VHI has been conceived as an efficient tool to monitor droughts in the Negueb watershed,southeastern Tunisia.The revised universal soil loss equation(RUSLE)model was applied to quantitatively estimate soil erosion.The relationship between soil erosion and droughts was investigated through Pearson correlation.Results exhibited that the Negueb watershed experienced recurrent mild to extreme drought during 2000–2016.The average soil erosion rate was determined to be 1.8 t/(hm2•a).The mountainous western part of the watershed was the most vulnerable not only to soil erosion but also to droughts.The slope length and steepness factor was shown to be the most significant controlling parameter driving soil erosion.The relationship between droughts and soil erosion had a positive correlation(r=0.3);however,the correlation was highly varied spatially across the watershed.Drought was linked to soil erosion in the Negueb watershed.The current study provides insight for natural disaster risk assessment,land managers,and stake-holders to apply appropriate management measures to promote sustainable development goals in fragile environments.

Depression among medical students in Tunisia:Prevalence and associated factors

BACKGROUND Medical school is known for its lengthy process,which is both physically and emotionally draining.Students’mental balance would shrink as they progress in their medical training.A systematic review and meta-analysis reported that the prevalence of depressive symptoms among medical students remained relatively constant at 27.2%.AIM To assess the prevalence of depressive symptoms among Tunisian medical students and evaluate its associated factors.METHODS This is a descriptive cross-sectional study that was carried out in the second semester of the academic year 2017/2018,between April 2018 and July 2018 among 1138 medical students.Data were collected using a socio-demographic questionnaire and the Beck Depression Inventory-II(BDI-II).RESULTS Sixty-four percent(n=728)of the participants had depressive symptoms,of which 266(23.4%)met the criteria for mild,271(23.8%)for moderate,and 191(16.8%)for severe depressive symptoms.Female gender,low socio-economic level,smoking habits and history of mental disorder,performing leisure and physical activities,satisfaction toward a career choice,and happiness perception were the main prognostic factors for depression among medical students.Although academic grades may not be considered a prognostic factor,final-year students appeared to be less depressive than their colleagues.CONCLUSION These findings give insight into mental health issues and comorbidities among Tunisian medical students.It is a hopeful request for decision-makers and academic authorities to set serious measures and draw effective interventions to minimize the currency of psychological distress among this subpopulation.

Potential risk of soil irrigation with treated wastewater over 40 years:a field experiment under semi-arid conditions in northeastern Tunisia

In Tunisia,water scarcity is only adding pressure on water demand in agriculture.In the context of sustainable development goals,Tunisia has been reusing treated wastewater(TWW)as a renewable and inexpensive source for soil fertigation and groundwater(GW)recharge.However,major risks can be expected when the irrigation water is of poor quality.This study aims for evaluating the potential risk of TWW and GW irrigation on soil parameters.Accordingly,we evaluated the suitability of water quality through the analysis of major and minor cations and anions,metallic trace elements(MTEs),and the sodium hazard by using the sodium adsorption ratio(SAR)and the soluble sodium percentage(SSP).The risk of soil sodicity was further assessed by SAR and the exchangeable sodium percentage(ESP).The degree of soil pollution caused by MTEs accumulation was evaluated using geoaccumulation index(Igeo)and pollution load index(PLI).Soil maps were generated using inverse spline interpolation in ArcGIS software.The results show that both water samples(i.e.,TWW and GW)are suitable for soil irrigation in terms of salinity(electrical conductivity<7000μS/cm)and sodicity(SAR<10.00;SSP<60.00%).However,the contents of PO_(4)^(3-),Cu^(2+),and Cd^(2+)exceed the maximum threshold values set by the national and other standards.Concerning the soil samples,the average levels of SAR and ESP are within the standards(SAR<13.00;ESP<15.00%).On the other hand,PLI results reveal moderate pollution in the plot irrigated with TWW and no to moderate pollution in the plot irrigated with GW.Igeo results indicate that Cu^(2+)is the metallic trace element(MTE)with the highest risk of soil pollution in both plots(Igeo>5.00),followed by Ni^(2+)and Pb^(2+).Nevertheless,Cd^(2+)presents the lowest risk of soil pollution(Igeo<0.00).Statistical data indicates that Ca^(2+),Na+,Ni^(2+),and Pb^(2+)are highly distributed in both plots(coefficient of variation>50.0%).This study shows that the use of imagery tools,such as ArcGIS,can provide important information for evaluating the current status of soil fertility or pollution and for better managing soil irrigation with TWW.

“全球发展倡议”视域下中国与突尼斯的抗疫合作

“阿拉伯之春”和新冠肺炎疫情的叠加对突尼斯的经济与社会发展造成巨大冲击,打造卫生健康共同体和发展共同体成为中国与突尼斯抗疫合作的逻辑与目标。“全球发展倡议”对于战胜疫情和复苏经济做出了明晰的规划与部署,对于中国与突尼斯以南南合作为实质的抗疫合作形成了新的助力作用。中国对突尼斯的医疗援助已走过50余年历程。就中突抗疫合作的路径而言,中国一方面将常规援突医疗队的职能扩大到兼顾对突应急抗疫合作,并实现多批援突医疗队的正常轮换,做到了常规合作与应急合作的结合;另一方面基于疫苗多边主义,向突尼斯适时应急提供新冠疫苗。中突抗疫合作不仅对于突尼斯疫情缓解和疫苗接种率的提升起到了重要作用,提升了中突政治互信,而且也助力中突关系朝着更深广的领域发展,如数字经济、文化合作和绿色发展合作等。中突抗疫合作事实上促进了两国卫生健康共同体与发展共同体建设,并助力推进双边关系取得更大发展。

突尼斯软籽石榴防寒越冬措施的防护效果

【目的】通过调查分析大田及冷棚突尼斯软籽石榴冬季不同防寒越冬措施的防护效果,筛选出适宜的防寒越冬措施,为突尼斯软籽石榴的安全过冬提供理论依据与技术支撑。【方法】以1年生突尼斯软籽石榴为试材,在12连设置露地3种覆土厚度下的7种物理保护措施共21个处理,测定不同物理防寒措施下,石榴树体周围的温湿度变化情况,并调查分析翌年春季突尼斯软籽石榴的冻害情况;以3年生突尼斯软籽石榴为试材,在20连设置5种和19连设置2种防寒保护措施,调查分析翌年春季石榴的冻害情况,以筛选适宜的冬季防寒越冬措施。【结果】草帘+钢筋+覆土以及草帘+塑料膜+覆土的防寒措施对软籽石榴安全越冬效果较好,均可有效提高石榴树体微环境的湿度、日平均温度及日最低温度,且草帘+塑料膜+覆土15 cm防寒措施下的突尼斯软籽石榴整体冻害最轻(冻害指数8.3%)。冷棚内不同覆盖方式中最好的物理保护措施是草帘+拱棚,突尼斯软籽石榴苗均未遭受冻害,保护效果较好的物理保护措施为毛毡和覆土。【结论】新疆冬季气候寒冷,在传统埋土防寒措施下,突尼斯软籽石榴仍发生严重冻害,需采取其他物理保护措施与覆土相结合的方式,才能有效地避免突尼斯软籽石榴遭受冻害。草帘+塑料膜+覆土15 cm防寒措施下的突尼斯软籽石榴整体冻害最轻,可以在生产中推广应用。单纯的冷棚设施栽培并不能对突尼斯软籽石榴起到良好的防冻效果,在冷棚内搭建小拱棚并在其上覆盖草帘能够保证软籽石榴安全越冬。

Chemical and Organic Contamination of Phreatic Aquifer of Sidi Bouzid （Center West of Tunisia）

An understanding of the long-term changes in the nitrate and microbial contamination pattern of the groundwater of Sidi Bouzid （Centre West of Tunisia） is critical to conservation of drinking water in rural areas supporting mixed land-use activities such as cropping, livestock farming, and residence. The phreatic aquifer was revealed polluted by domestic disposals of the wastewaters in the urban zone. The average nitrate concentration in the groundwater of the east of the mioplioquaternary aquifer of Saddaguia （Sidi Bouzid） rose from 50 mg NO3- during 1996 to over 100 mg in 2003, which represents an increase of some 10 mg per year. Nitrate groundwater pollution during the period 1996-2003 was the result of the abusive use of fertilizers.In the cultivated zone, we must reduce the effects of the excessive use of the nitrogen fertilizers on the basis of monitoring soil once a year, managing water resources, rationalizing the use of the chemical substances. In urban zones, most of lost wells located in the perimeter reveal the gravity of the state of the aquifer. This last is organically polluted and requires an immediate action for the generalization of the purification network. We need to take into account the reality of under soil in all future planning＇s and arrangements. A scheme of sanitation seems necessary before all plans of arrangement. The extension of the sewer network must give the priority to the most vulnerable zones.

突尼斯治理非政府组织的法律成效探析

突尼斯历届政府依据国内法律、政府令和政府部门条例,依托中央政府秘书长和地方省政府的双层治理机制,对国内非政府组织开展治理。在具体治理过程中,突尼斯政府采取扶持与管控并行的双重治理模式:在扶持方面,政府明确赋予非政府组织政治和经济权利;在管控方面,政府严格控制非政府组织的注册流程、基本信息、人员构成、资金使用,同时规定违规的处罚力度。突尼斯治理非政府组织的成效与困境并存。一方面,政府实现了严格限制非政府组织运行的目的,非政府组织则扩大了自身规模和活动范围。另一方面,突尼斯行政部门对相关法律理解不深,对赋权以及非法管控落实不力,使得政府难以深入治理非政府组织。究其根本,突尼斯法律制定匆忙且不完善,法律内容结合国情不足且后续修订受阻,同时非政府组织配合执法的力度不够。未来,即便突尼斯政府沿用对非政府组织的双重治理模式,修订法律走出治理困境仍是政府提升治理能力、有效约束非政府组织的关键。

Modelling the spatial distribution of snake species in northwestern Tunisia using maximum entropy(Maxent) and Geographic Information System(GIS)

We used GIS and maximum entropy to predict the potential distribution of six snake species belong to three families in Kroumiria（Northwestern Tunisia）： Natricidae（Natrix maura and Natrix astreptophora）, Colubridae（Hemorrhois hippocrepis, Coronella girondica and Macroprotodon mauritanicus）, and Lamprophiidae（Malpolon insignitus）. The suitable habitat for each species was modelled using the maximum entropy algorithm, combining presence field data（collected during 16 years：2000–2015） with a set of seven environmental variables（mean annual precipitation, elevation, slope gradient,aspect, distance to watercourses, land surface temperature and normalized Differential Vegetation Index. The relative importance of these environmental variables was evaluated by jackknife tests and the predictive power of our models was assessed using the area under the receiver operating characteristic. The main explicative variables of the species distribution were distance from streams and elevation, with contributions ranging from 60 to 77 and from 10 to 25%,respectively. Our study provided the first habitat suitability models for snakes in Kroumiria and this information can be used by conservation biologists and land managers concerned with preserving snakes in Kroumiria.

Cadmium bioaccumulation in three benthic fish species, Salaria basilisca, Zosterisessor ophiocephalus and Solea vulgaris collected from the Gulf of Gabes in Tunisia

To select a marine teleost fish which can be used as a bioindicator of cadmium （Cd） pollution in the Gulf of Gabes in Tunisia, Cd concentrations in liver and gill were compared in three benthic fish species including Salaria basilisca, Zosterisessor ophiocephalus and Solea vulgaris. Fish samples were collected from three selected sites in the Gulf of Gabes, with different degrees of Cd contamination： the industrialized coast of Sfax （S 1）, the coast of Douar Chatt （S2） and the coast of Luza （S3）. The results shows that Cd concentrations in both sediment and water collected from S1 were significantly higher （t9 〈 0.0001） than those from S2 and S3. For each species, Cd concentrations, in both liver and gill, showed the decreasing order： S 1 〉 S2 〉 S3. The highest concentration of Cd was detected in the liver of S. basilisca, and only S. basilisca showed bioaccumulation factors （BAF） greater than 1 in all studied sites. In S 1 and S2, BAF values respect the following order： S. basilisca 〉 Z. ophiocephalus 〉 S. vulgaris. These results of significant bioaccumulation of Cd, in terms of hepatic concentrations and bioaccumulation factors, indicated that S. basilisca can be used as bioindicator to evaluate the evolution of Cd pollution in the Gulf of Gabes.

Variations of Natural Soil Salinity in an Arid Environment Using Underground Watertable Effects on Salinization of Soils in Irrigated Perimeters in South Tunisia

In arid and semi-arid regions, salinity is a serious and chronic problem for agriculture. The aim of this study is to evaluate the hydromorphical and salinity risks, and to evaluate the relationship and the possible interfering between the water table and the soil on the oasis of Gabes. The topic is very important, especially for nations around the oceans in arid and semi-arid regions. The effect of the gypsum alkalinity in the soil salinity has investigated. The chemical characteristic of used water irrigation (salinity saturation) and their impact factor in the productivity area. Moreover, in this study the program of examination need to put fifteen piesometres by CRAD (Regional Commissariat of Agriculture Development) in the city of Gabes to controlling the variation of water levels in the superficial water table and their change chemical quality. The experimental measure of this program needs a yearly observation and investigation during April and May to evaluate the hydromorphical and salinity risks on the oasis of Gabes. The relationship and the possible interfering between the water table and the soil has evaluate in such condition.

Vertical Accuracy Assessment of SRTM Ver 4.1 and ASTER GDEM Ver 2 Using GPS Measurements in Central West of Tunisia

This paper focuses on the quality of the vertical accuracy of two Digital Elevation Models, corresponding to Kasserine region, central west Tunisia. The vertical accuracy assessment is based on 23 GPS ground control points belonging to the study area. We applied a statistic analysis approach and established 3 elevation profiles corresponding to GPS, ASTER and SRTM. The erected statistical analysis reveals that the Root Mean Squared Error (RMSE) was 8.88 and 10.13 respectively for SRTM and ASTER DTMs. 2D elevation profiles constructed for GPS measurements, ASTER and SRTM, highlight that both DTMs underestimate the true elevation and that SRTM DTM is quite closer to the GPS elevation profile. Relying on this investigation, we think that both DTMs are significant for the vertical accuracy assessment and we urge that SRTM DTM might scheme the Kasserine area features better than ASTER DTM.

Structural Interpretation of Lineaments Uses Satellite Images Processing: A Case Study in North-Eastern Tunisia

This paper presents a lineament detection method using multi-band remote sensing images. The main objective of this work is to design an automatic image processing tool for lineament mapping from Landsat-7 ETM + satellite data. Five procedures were involved: 1) The Principal Component Analysis;2) image enhancement using histogram equalization technique 3) directional Sobel filters of the original data;4) histogram segmentation and 5) binary image generation. The applied methodology was contributed in identifying several known large-scale faults in the Northeast of Tunisia. The statistical and spatial analyses of lineament map indicate a difference of morphological appearance of lineaments in the satellite image. Indeed, all the lineaments present a specific organization. Five groups were classified based on three orientations: NE-SW, E-W and NW-SE. The overlapping of lineament map with the geologic map confirms that these lineaments of diverse directions can be identified and recognized on the field as a fault. The identified lineaments were linked to a deep faults caused by tectonic movements in Tunisia. This study shows the performance of the satellite image processing in the analysis and mapping of the accidents in the northern Atlas.

Association of hepatitis C virus infection and diabetes in central Tunisia

AIM：To investigate hepatitis C virus （HCV） seroprevalence in Tunisian patients with diabetes mellitus and in a control group. METHODS： A cross-sectional study was conducted to determine the HCV seroprevalence in 1269 patients with diabetes （452 male, 817 female） and 1315 nondiabetic patients, attending health centers in Sousse, Tunisia. HCV screening was performed in both groups using a fourth-generation enzyme immunoassay. RESULTS： In the diabetic group, 17 （1.3%） were found to be HCV-infected compared with eight （0.6%） in the control group, although the difference was not significant （P = 0.057）. Quantitative PCR was performed in 20 patients. Eleven patients were positive and showed HCV genotype lb in all cases. CONCLUSION： Frequency of HCV antibodies was low in patients with diabetes and in the control group in central Tunisia, with no significant difference between the groups.

Salinity Risk and Management in Tunisian Semi Arid Area

In semi arid and arid countries, the increase in production needs sometimes using brackish/saline water for irrigation. In Kairouan and Mahdia （Centre of Tunisia）, most of the irrigated areas are by pumping ground water from wells and in many cases, water has more than 4 g of salt per liter. To improve farmers＇ income through using efficiently brackish/saline and rare water, applied research programme was carried out. The methodology adopted was based on selection of six farmers＇ parcels. Behind water quality and quantity, soil salinity and crop response, the crop cost was studied： initial and final characterization and frequently controlled. Three different water regimes were observed induced three salinity regimes： an exclusively irrigated regime in summer based on using saline water producing continuous accumulation of salts, an irrigated-rained regime in autumn/spring based on alternated saline and fresh water inducing cyclic accumulation and leaching of salts and a rained regime in winter based on fresh water with continuous leaching of salts. At the short term, soil salinity increased under irrigation until equilibrium with the irrigation water quality and decreased by rain which produced an important salts leaching in a very short time. Many tons of salts were added to the initial stock in summer season and most of them are leached to the subsoil under irrigation and by rain in the winter. Salinization affected the deep layer and on the long term, salinization of the aquifer might occur. An important crop yield decrease for the summer crop was obtained but the socio-economic aspect appeared as an important factor conditioning the use of saline water.

Early severity predictors of snakebite envenomation in the southern region of Tunisia: a multivariate analysis

Objective:To identify the early predictors of severe envenomation in the southern region of Tunisia.Methods:It was a retrospective monocentric study including consecutive patients admitted to the emergency department for snakebite envenomation.Snakebite envenomation was defined by a history of snakebite.Predictors of severe envenomation were determined by univariate and multivariate analyses.Results:Our sample consisted of 109 patients aged 30(20-44)years with a 1.1:1 sex-ratio(56 males and 53 females).During the 24-hour surveillance period,25 patients developed severe envenomation(22.9%).The in-hospital mortality rate was 4.6%(n=5).The independent predictors of severe snakebite envenomation were leucocyte count over 11550/mm3(OR:18.7,95%CI:3.3-107.8),creatine kinase over 155 IU/L(OR:6.16,95%CI:1.1-35.6),and/or tourniquet before arrival to the ED(OR:32.14,95%CI:3.5-295.9).Conclusions:This study emphasizes the importance of early evaluation of snakebite envenomation.Further studies are required to approve a severity scale proper to snakebite envenomation in Tunisia.

Integrating multiple electromagnetic data to map spatiotemporal variability of soil salinity in Kairouan region, Central Tunisia

Soil salinization is a major problem affecting soils and threatening agricultural sustainability in arid and semi-arid regions,which makes it necessary to establish an efficient strategy to manage soil salinity and confront economic challenges that arise from it.Saline soil recovery involving drainage of shallow saline groundwater and the removal of soil salts by natural rainfall or by irrigation are good strategies for the reclamation of salty soil.To develop suitable management strategies for salty soil reclamation,it is essential to improve soil salinity assessment pro cess/mechanism and to adopt new approaches and techniques.T his study mapped a recovered area of 7200 m2 to assess and verify variations in soil salinity in space and time in K airouan region in Central Tunisia,taking into account the thickness of soil materials.Two electromagnetic conductivity meters(EM38 and EM31)were used to measure the electrical conductivity of saturated soil-paste extract(ECe)and apparent electrical conductivity(E Ca).Multiple linear regression was established between ECe and ECa,and it was revealed that ECa-EM38 is optimal for E Ce prediction in the surface soils.Salinity maps demonstrated that the spatial structure of soil salinity in the region of interest was relatively unchanged but varied temporally.Variation in salinity at the soil surface was greater than that at a depth.These findings can not only be used to track soil salinity variations and their significance in the field but also help to identify the spatial and temporal features of soil salinity,thus improving the efficiency of soil management.

Geochemical Behaviour of the Tunisian Background Aerosols in Sirocco Wind Circulations

This study examines spatial and time evolutions of the principal constituents of the Tunisian background aerosols under Sirocco wind circulations. Aerosols coming from the Sahara Desert were found to be loaded with particulate matter, especially silicon. The aerosols were shown to have varying geochemical behaviour along the ＂South-North＂ displacement of the Saharan plumes, depending on the wind flow characteristics, geomorphologic features and the nature of soils swept by the wind. In the south and the center part of the country, the transfer of aerosol constituents to the soil （by gravity and/or impaction） was probably predom- inated by localized enrichment phenomena. The latter are reinforced by the effect of turbulent winds over bare soils, wind wakes and probably selective disintegration, especially in the vicinity of the geomorphologic features of central Tunisia. These relatively high features, extending over important distances, appear to be of paramount importance for the phenomena of redistribution of aerosol constituents even during periods without Sirocco wind circulations. In the northern section of the country, aerosol constituent concentrations dropped to almost 50%, in spite of the abundance of localized turbulent winds. This may be explained by the effect of forests and the relatively dense vegetation cover, which clearly reinforces the transfer phenomena to the soil and the attenuate of dust entrainment.

First investigation of deltamethrin pyrethroid susceptibility and resistance status of Anopheles labranchiae(Falleroni, 1926), potential malaria vector in Tunisia

Objective: To evaluate the deltamethrin pyrethroid insecticides against Anopheles labranchiae, potential malaria vector in Tunisia.Methods: Six field populations of Anopheles labranchiae mosquitoes were collected from six localities in Northern and Central Tunisia between October and November 2016.Different bioassays were performed to estimate the level of resistance in each collected population. Two synergists were used to estimate the involvement of detoxification enzymes in insecticide resistance.Results: All studied strains were resistant and the RR50 ranged from 12.5 in sample #1 to72.5 in sample #6. Synergist tests using piperonyl butoxide indicated the involvement of monoxygenases enzymes in the recorded resistance. In contrast, the increase of deltamethrin mortality was not significant in presence of S,S,sributyl phosphorothioate(0.8 < SR < 1.2), suggesting no role of esterases(and/or GST) in the resistance phenotype. The correlation recorded between mortality due to DDT and the LC50 of deltamethrin insecticide indicated an insensitive sodium channel affected by Kdr mutation(Spearman rank correlation, r =-0.59, P < 0.01).Conclusions: These results should be considered in the current mosquitoes control programs in Tunisia. The use of pesticides and insecticides by both agricultural and public health departments in Tunisia should be more rational to reduce the development of resistance in populations. Different insecticide applications should be implemented alternately.

Agro-biodiversity and Traditional Knowledge on Tunisian Coastal Oases

The Tunisian coastal oases constitute a model of very rich plant biodiversity, organized in different floors of cultivation. The date palm is the highest, the second is the diversified fruit trees and the smallest is composed by various other productions. The present paper is the results of a RAA diagnosis and bibliographic analysis of nearly thirty years of work on oases. The aim of this study is to focus on the plant diversity and the traditions in using different products. The survey revealed the existence of nearly 45 local date palm varieties, about 26 fruit trees, 65 vegetables and divers other species. It also raises nearly 30 uses of dates and date palm by-products. This survey shows also that oases inhabitants keep in possessing, for a long time, a knowledge to make ingenious concerning use and conservation of the products and by products of the date palm. This survey has all as much demonstrated the risks from weakening this balance which has long been maintained. Some recommendations to maintain and conserve this system are also presented in this paper.