Evaluation of rainwater harvesting and shrub establishment methods for sustainable watershed management in northern Afghanistan

Watershed rangelands in Northern Afghanistan provide various ecosystem services that support the local people’s livelihoods, but they are now highly degraded essentially due to the continuous high grazing pressure and recurrent droughts. Effects of shrub establishment method enhanced by water harvesting techniques to rehabilitate degraded rangelands have not been well addressed. The main goal of this study was to evaluate the impact of direct seeding and transplanting of seedlings in combination with semi-circular bunds on growth, yield, and survival rate of four shrub species (Atriplex halimus, Atriplex nummularia, Atriplex lentiformis, and Maireana brevifolia) under semi- arid conditions of Sayyad village, Khulm watershed. Survival rate (%), plant height, width, and plant length (cm) and plant cover (%) were measured for each plant over five occasions. A non-destructive reference unit was used to estimate biomass production. The results showed that growth attributes and biomass production of shrubs were consistently greater in the transplanting compared to direct seeding. On average, the plant length, width, height, volume, cover, and biomass production of transplanted shrubs were greater than direct-seeded shrubs by 24.3%, 8.6%, 8.7%, 121.5%, 13.8% and 34.1%, respectively. Biomass production of transplanted seedlings was the highest for A. nummularia (1313.5 g DM/plant) and A. halimus (800 g DM/plant). There was a strong correlation between plant biomass production and plant volume (R2 Plant volume = 0.88) for the shrub A. nummularia, indicating that plant volume is a key variable for assessing biomass production for this species. Additionally, the survival rate of M. brevifolia was 100% in both planting methods, suggesting that based on better survival this halophytic plant has great potential when restoring degraded rangelands. Collectively, on the basis of better growth rates, yield, and survival, transplanting A. nummularia and A. halimus may enhance shrub establishment and contribute to the rehabilitation of sloping semi-arid degraded areas of Northern Afghanistan

Characterizing Biomass Yield and Nutritional Value of Selected Indigenous Range Species from Arid Tunisia

Rangelands of Tunisia show a great indigenous species diversity with considerable potential as forage for livestock. However, information on their fodder yield and quality is scanty and restricted to few species. The objective of the study was to evaluate the nutritive values of selected key perennial species based on their biomass yield, chemical composition, in vitro organic matter digestibility (IVOMD), and mineral composition. The species evaluated included four grass species (Stipa lagascae Roem. and Schult., Stipa tenacissima L., Stipagrostis plumosa (L.) Munro ex T. Anderson, and Stipagrostis pungens (Desf.) de Winter.) and eight shrub species (Anthyllis henoniana Coss. ex Batt., Argyrolobium uniflorum (Deene.) Jaub. and Spach., Echiochilon fruticosum Desf., Gymnocarpos decander Forssk., Helianthemum kahiricum Delile., Helianthemum lippii (L.) Dum. Cours., Plantago albicans L. and Rhanterium suaveolens Desf.). Results showed that shrub species contained higher concentrations of the crude protein (CP), acid detergent lignin (ADL), but lower neutral detergent fiber (aNDFom) and acid detergent fiber (ADFom) concentrations than grasses. The greatest concentration of CP was 135 g/kg DM for R. suaveolens. The greatest aNDFom concentration was found within the grasses with maximum of 744.5 g/kg DM in S. plumosa. The shrub species E. fruticosum, A. uniflorum, P. albicans, G. decander, R. suaveolens, and A. henoniana had the highest IVOMD with over 500 g/kg DM and have the potential to supply energy to livestock. Overall, the moderate to high protein, low fiber, and high in vitro digestibility measured for shrubs, suggest they have high nutritional values and can be used to enhance local livestock production

Numerical and experimental study of central jet displacement effects on the dynamics of a coaxial burner

International audienc

Evaluation of carbon stock in the sediment of two mangrove species, Avicennia marina and Rhizophora mucronata, growing in the Farasan Islands, Saudi Arabia

The aim of this study was to conduct the first comprehensive evaluation of carbon stock in the sediments of Avicennia marina (black mangrove) and Rhizophora mucronata (red mangrove) along the coastline of an arid region (Farasan Islands, Saudi Arabia). Such information is necessary for the development of any management plan for the mangrove ecosystems along the Saudi Red Sea islands and provide a rationale for the restoration of mangrove forests in Saudi Arabia. A. marina and R. mucronata locations showed significant (P < 0.001) differences in sediment bulk density (SBD) and sediment organic carbon (SOC) concentration with higher mean values for both in the sediments of A. marina. Considering the whole depth of sediment sampled (0–50 cm), the highest value of SOC stock (12.3 kg C m−2) was recorded at A. marina locations and the lowest (10.8 kg C m−2) at R. mucronata locations. Thus, the SOC stock of A. marina was greater than that of R. mucronata by 114.3%. Consequently, considering the rate of carbon sequestration and the area of mangrove forests (216.4 ha), the total carbon sequestration potential of mangroves in the Farasan Islands ranged between 10.3 Mg C yr−1 and 11.8 Mg C yr−1 for R. mucronata and A. marina locations, respectively. Thus, it is necessary to protect and restore these ecosystems for the sequestration of carbon and for their other valuable ecosystem services

Effet du pâturage sur la diversité floristique des parcours arides du sud tunisien

International audienc

Comparaison morphologique de deux souches de Monacrosporium salinum, champignon prédateur de nématode, isolées d’un agro-écosystème tunisien et omanais

Monacrosporium salinum strain, MSO03, isolated from Omani horticultural agro-ecosystem in 2003, has been compared to patented strains, MST84, isolated in 1984 from Tunisian soils. Morpho-biometrical characteristics demonstrated that MSO03 was similar to MST84. However, conidia of MSO03 were longer as compared to those of MST84. Furthermore, MSO03 strain produce specifically single chlamydospores rounded, showing thick cell wall, while known M. salinum chlamydospores are flattened, in chains with thin cell wall. Consequently, the Omani strain MSO03 can resist to more severe stress conditions, such as drought and extreme temperature, occurring in Omani agro-ecosystems. Generally, the predatory antagonistic activity toward Tylenchulus semipenetrans and Meloidogyne javanica was similar for both M. salinum strains.La souche de Monacrosporium salinum MSO03, isolée en 2003 d’un agro-écosystème horticole au sultanat d’Oman, a été comparée à la souche tunisienne MST84, brevetée, de la même espèce et isolée depuis 1984. L’utilisation des caractéristiques morpho-biométriques a montré que la souche MSO03 est similaire à la souche MST84. Cependant, les conidies de MSO03 sont plus longues que celles de MST84. En outre, la souche omanaise produit des chlamydospores formées par une seule cellule arrondie à membrane épaisse, contrairement aux chlamydospores de Monacrosporium salinum connues et qui sont formées de cellules aplaties, en chaînes et présentant une membrane mince. Par conséquent, la souche omanaise MSO03 peut résister aux conditions adverses telles que la sécheresse et les températures extrêmes caractérisant les agro-écosystèmes omanais. L’activité prédatrice de ces champignons vis-à-vis de Tylenchulus semipenetrans et de Meloidogyne javanica est similaire pour les deux souches de M. salinum.Elfékih Samia, Kallel Sadreddine, Abdelwahed A., Al-Hinai Sulaiman, B’Chir Mohamed Mouldi. Comparaison morphologique de deux souches de Monacrosporium salinum, champignon prédateur de nématode, isolées d’un agro-écosystème tunisien et omanais. In: Ecologia mediterranea, tome 38 n°1, 2012. pp. 81-88

Sustainable silvopastoral restoration to promote ecosystem services in Tunisia

this chapter is describing the The silvopastoral improvement accomplished in the region of Sbaihia, Tunisia thet relies on a sound participatory approach with full cooperation from the local population who contributed to the main decisions implemented onsite

Analysis of thermal density and heat sink on dissipative nanofluid along magnetized sheet and applications in microelectronic cooling systems

The objective of present analysis is to control excessive thermal behavior in microelectronic devices using heat sink and magnetic field. Improving technological innovation demands proper temperature evacuation in microelectronic components. A feasible method for cooling microelectronics is to use nanofluid, a novel heat-transport liquid. To achieve significant cooling, microelectronic devices must be small with specific operating liquids than regular liquids. The present work investigates the fluid motion and heat transmission properties of nanofluids as advanced cooling fluids for microelectronic coolant systems. A numerical technique is used to investigate the cooling mechanism using stretching surface. Computational fluid dynamics and 2D liquid movement simulation are employed to determine the mathematical model. The governing model is transformed with Keller box method and Newton Raphson technique through MATLAB program. The base liquid is water using laminar motion. The influence of nanoparticles volume fraction, heat sink, variable density and viscous dissipation in the base liquid on heat transmission efficiency of coolant devices is investigated. It is noticed that the fluid temperature decreases as heat sink increases. It is found that the excessive heat is reduced by using magnetic layer and heat sink. The present numerical mechanism is significant for the cooling of microelectronic devices