Sustainable Rangeland Management Toolkit for Resilient Pastoral Systems

This toolkit is a collection of adaptable site-specific Sustainable Rangeland Management practices that developed to manage rangelands in the dry areas, achieving a neutral level of degradation and offering a strong potential to restore degraded rangelands. It is a result of collaboration among three institutions – the International Livestock Research Institute (ILRI), the International Center for Agriculture Research in the Dry Areas (ICARDA) and the International Union for Conservation of Nature (IUCN). The flexibility of the SRM toolbox within different agroecological scenarios raises its potential for upscale across the dry areas

Ingestive behavior of cattle grazing in lightly- and heavily-grazed patches of Lehmann lovegrass (Eragrostis lehmanniana Nees).

Cattle grazing patterns on Lehmann lovegrass rangelands often create heavily-grazed (HG) areas surrounded by lightly-grazed (LG) or ungrazed patches. The purpose of this study was to characterize the forage resource and ingestive behavior of cattle grazing Lehmann lovegrass plants in both LG and HG patches on the Santa Rita Experimental Range. The general hypothesis was that residual bunchgrass vegetation resulted in sward characteristics which physically inhibited the efficiency of cattle grazing by increasing the manipulative activity per harvested bite. The overall heights of residual stems and green tillers averaged 70 and 49 cm for LG, 8 and 9 cm for HG patches. Biomass of total standing crop (SC), residual vegetation (RV) and green herbage (GH) averaged 4159, 3395 and 764 kg/ha for LG, 345, 185 and 160 kg/ha for HG patches, respectively. Bulk density of SC, RV and GH of LG and HG patches averaged 58, 48, and 19 [(gm/cm³) X 10⁻⁵] for LG, 38, 23 and 20 [(gm/cm³) X 10⁻⁵] for HG patches, respectively. The ratio of green herbage to residual vegetation averaged 0.22 for LG and 0.86 for HG patches. The different sward structure of LG and HG patches affected the ingestive behavior of the grazing cows. Overall handling time for each grazing bite averaged 1.5 and 1.2 sec/bite in LG and HG patches, respectively. Cows employed different foraging tactics in response to the dynamic changes of the sward conditions. Cows employed top biting extensively to harvest the seed-head and other green herbage at the top of the sward surface. As the height of residual stems increased and dominated the upper strata of the sward, side and low biting were mainly used by the cows as grazing methods to bite the plants to reduce the manipulative activity. Avoidance of LG patches or preference for HG patches was related to the sward structure and largely shaped by the build-up of residual vegetation. Removal of residual vegetation through fire, mowing or heavy utilization for short periods late in the growing season to allow for more accessible green herbage could improve both animal and pasture utilization of the range resource

Fairness models to improve the quality of service in ad-hoc wireless networks

L’objectif de ce travail est l’amélioration de la qualité de service (QdS) dans les réseaux sans fil ad-hoc avec équité. La QdS dans les réseaux sans fil ad-hoc est actuellement définie par la norme IEEE802.11e (EDCA). Elle permet de garantir l’accès prioritaire aux ressources pour le trafic de priorité élevé (trafic temps réel et trafic multimédia). Elle est mise en œuvre dans chaque station par la classification des paquets dans différentes file d'attente caractérisant chacune une classe de trafic à laquelle est associée une priorité de traitement. Toutefois, EDCA n’est pas un protocole équitable. En effet, lorsque un nœud participe au routage du trafic des ces voisins, son trafic propre se trouve réduit. Pour résoudre ce problème, nous proposons un nouveau modèle appelé F-EDCA. Ce modèle permet à un nœud routeur d’accéder plus régulièrement au réseau en fonction de son taux d’occupation. Une autre forme de non équité résulte de la position d’un nœud source par rapport au nœud destination. Plus le nœud source est éloigné, moins il a de bande passante. Pour résoudre ce problème, nous proposons FQ-EDCA. Il améliore la QdS en distinguant dans chaque classe de trafic, une file d’attente par source de trafic. Le modèle met alors en œuvre des techniques d’ordonnancement équitable en se basant sur la technique du temps virtuel. Ainsi, les ressources sont allouées équitablement entre tous les nœuds. F-EDCA et FQ-EDCA sont mis en œuvre et évaluées de manière comparative avec EDCA. Ce travail montre que chacun d'eux améliore EDCA et pourrait allouer équitablement les ressources dans des conditions différentes et augmenter la garantie de la QdSThis thesis aims to enhance the quality of service (QoS) in wireless ad-hoc networks with fairness. The QoS in wireless ad-hoc networks is referred to the standard IEEE802.11e (EDCA) to guarantee the high priority traffic (i.e. Multimedia and Real-time traffics). Further, the QoS is managed in each station by differentiating the packets in categories to be queued depending on their priorities. Then, these packets will access the channel in different waiting time. However, EDCA cannot control the heavy traffic caused by the ill-behaved users. So, if the traffic is regulated with fairness, it could resolve some of networks’ problems like the congestion and starvation. These problems degrade the QoS guarantee, because the ill-behaved sources consume the majority of the allocated resources. That leads to some of source nodes suffer from the lack of bandwidth and unfairness. So, without a proper control mechanism, it could decrease the QoS guarantees. Therefore, we propose (FQ-EDCA) that is a Fairness Queuing model for EDCA. It enhances the QoS by implementing scheduling techniques and improving the architecture of EDCA. Thereby, the traffic is regulated between the source nodes by separating the ill-behaved sources. Thus, the resources are allocated fairly between all the source nodes. Further, a fairness model (F-EDCA) is proposed to differentiate between two source nodes. One of them is routing packets of its neighbors and the other is only sending its packets. Both of these models are implemented and evaluated with EDCA. As a consequence, each of them enhances EDCA, could allocate the resources with fairness in different conditions and increase the QoS guarante

Modèles d'équité pour l'amélioration de la qualité de service dans les réseaux sans fil en mode ad-hoc

This thesis aims to enhance the quality of service (QoS) in wireless ad-hoc networks with fairness. The QoS in wireless ad-hoc networks is referred to the standard IEEE802.11e (EDCA) to guarantee the high priority traffic (i.e. Multimedia and Real-time traffics). Further, the QoS is managed in each station by differentiating the packets in categories to be queued depending on their priorities. Then, these packets will access the channel in different waiting time. However, EDCA cannot control the heavy traffic caused by the ill-behaved users. So, if the traffic is regulated with fairness, it could resolve some of networks’ problems like the congestion and starvation. These problems degrade the QoS guarantee, because the ill-behaved sources consume the majority of the allocated resources. That leads to some of source nodes suffer from the lack of bandwidth and unfairness. So, without a proper control mechanism, it could decrease the QoS guarantees. Therefore, we propose (FQ-EDCA) that is a Fairness Queuing model for EDCA. It enhances the QoS by implementing scheduling techniques and improving the architecture of EDCA. Thereby, the traffic is regulated between the source nodes by separating the ill-behaved sources. Thus, the resources are allocated fairly between all the source nodes. Further, a fairness model (F-EDCA) is proposed to differentiate between two source nodes. One of them is routing packets of its neighbors and the other is only sending its packets. Both of these models are implemented and evaluated with EDCA. As a consequence, each of them enhances EDCA, could allocate the resources with fairness in different conditions and increase the QoS guaranteeL’objectif de ce travail est l’amélioration de la qualité de service (QdS) dans les réseaux sans fil ad-hoc avec équité. La QdS dans les réseaux sans fil ad-hoc est actuellement définie par la norme IEEE802.11e (EDCA). Elle permet de garantir l’accès prioritaire aux ressources pour le trafic de priorité élevé (trafic temps réel et trafic multimédia). Elle est mise en œuvre dans chaque station par la classification des paquets dans différentes file d'attente caractérisant chacune une classe de trafic à laquelle est associée une priorité de traitement. Toutefois, EDCA n’est pas un protocole équitable. En effet, lorsque un nœud participe au routage du trafic des ces voisins, son trafic propre se trouve réduit. Pour résoudre ce problème, nous proposons un nouveau modèle appelé F-EDCA. Ce modèle permet à un nœud routeur d’accéder plus régulièrement au réseau en fonction de son taux d’occupation. Une autre forme de non équité résulte de la position d’un nœud source par rapport au nœud destination. Plus le nœud source est éloigné, moins il a de bande passante. Pour résoudre ce problème, nous proposons FQ-EDCA. Il améliore la QdS en distinguant dans chaque classe de trafic, une file d’attente par source de trafic. Le modèle met alors en œuvre des techniques d’ordonnancement équitable en se basant sur la technique du temps virtuel. Ainsi, les ressources sont allouées équitablement entre tous les nœuds. F-EDCA et FQ-EDCA sont mis en œuvre et évaluées de manière comparative avec EDCA. Ce travail montre que chacun d'eux améliore EDCA et pourrait allouer équitablement les ressources dans des conditions différentes et augmenter la garantie de la Qd

Fairness models to improve the quality of service in ad-hoc wireless networks

L objectif de ce travail est l amélioration de la qualité de service (QdS) dans les réseaux sans fil ad-hoc avec équité. La QdS dans les réseaux sans fil ad-hoc est actuellement définie par la norme IEEE802.11e (EDCA). Elle permet de garantir l accès prioritaire aux ressources pour le trafic de priorité élevé (trafic temps réel et trafic multimédia). Elle est mise en œuvre dans chaque station par la classification des paquets dans différentes file d'attente caractérisant chacune une classe de trafic à laquelle est associée une priorité de traitement. Toutefois, EDCA n est pas un protocole équitable. En effet, lorsque un nœud participe au routage du trafic des ces voisins, son trafic propre se trouve réduit. Pour résoudre ce problème, nous proposons un nouveau modèle appelé F-EDCA. Ce modèle permet à un nœud routeur d accéder plus régulièrement au réseau en fonction de son taux d occupation. Une autre forme de non équité résulte de la position d un nœud source par rapport au nœud destination. Plus le nœud source est éloigné, moins il a de bande passante. Pour résoudre ce problème, nous proposons FQ-EDCA. Il améliore la QdS en distinguant dans chaque classe de trafic, une file d attente par source de trafic. Le modèle met alors en œuvre des techniques d ordonnancement équitable en se basant sur la technique du temps virtuel. Ainsi, les ressources sont allouées équitablement entre tous les nœuds. F-EDCA et FQ-EDCA sont mis en œuvre et évaluées de manière comparative avec EDCA. Ce travail montre que chacun d'eux améliore EDCA et pourrait allouer équitablement les ressources dans des conditions différentes et augmenter la garantie de la QdSThis thesis aims to enhance the quality of service (QoS) in wireless ad-hoc networks with fairness. The QoS in wireless ad-hoc networks is referred to the standard IEEE802.11e (EDCA) to guarantee the high priority traffic (i.e. Multimedia and Real-time traffics). Further, the QoS is managed in each station by differentiating the packets in categories to be queued depending on their priorities. Then, these packets will access the channel in different waiting time. However, EDCA cannot control the heavy traffic caused by the ill-behaved users. So, if the traffic is regulated with fairness, it could resolve some of networks problems like the congestion and starvation. These problems degrade the QoS guarantee, because the ill-behaved sources consume the majority of the allocated resources. That leads to some of source nodes suffer from the lack of bandwidth and unfairness. So, without a proper control mechanism, it could decrease the QoS guarantees. Therefore, we propose (FQ-EDCA) that is a Fairness Queuing model for EDCA. It enhances the QoS by implementing scheduling techniques and improving the architecture of EDCA. Thereby, the traffic is regulated between the source nodes by separating the ill-behaved sources. Thus, the resources are allocated fairly between all the source nodes. Further, a fairness model (F-EDCA) is proposed to differentiate between two source nodes. One of them is routing packets of its neighbors and the other is only sending its packets. Both of these models are implemented and evaluated with EDCA. As a consequence, each of them enhances EDCA, could allocate the resources with fairness in different conditions and increase the QoS guaranteeVILLENEUVE D'ASCQ-ECLI (590092307) / SudocSudocFranceF

Mineral assessment in Atriplex halimus L. and Atriplex nummularia L. in the arid region of Jordan

The foliage of Atriplex halimus contained higher levels (P < 0.05) of ash (28.03%) than that of Atriplex nummularia (23.11%). Spring growth of the two saltbushes contained less ash than the fall regrowth. The foliage of A. halimus contained higher levels of macro-minerals than A. nummularia plants except sodium. The two saltbushes contained higher levels of P, K and Mg during spring, but lower levels of Ca and Na compared to the growth of the fall season. Levels of Fe, Cu, Mn and Se present in the foliage of A. nummularia plants were higher than A. halimus. Clipping had no significant effect on ash content of saltbushes, but it affected the composition of the ash significantly. Clipping decreased the concentrations of Ca, P, Na, Mg and Fe in the foliage of clipped shrubs. The mineral composition of the two species of Atriplex appeared adequate to meet the requirements of sheep and goats grazing such types of forage.African Journal of Range & Forage Science 2003, 20(3): 247–25

Oxalate and tannins assessment in Atriplex halimus L. and A. nummularia L

The study was conducted at 3 locations in the arid region of Jordan to assess the seasonal changes of oxalate and tannins in Atriplex halimus L. and A. nummularia L. plants commonly used for revegetation of degraded rangelands. During spring and fall seasons, 20 shrubs of each species were selected randomly at each location, 20 similar twigs per shrub were clipped and analyzed for oxalate and tannins. Atriplex halimus contained higher levels of oxalate (7.00%) compared with A. nummularia plants (6.20%) (P < 0.001). Oxalate levels averaged 8.29 and 4.92% in spring and fall season, respectively. Plants of A. halimus accumulated more oxalate in spring than those of A. nummularia. Clipping had no effect on oxalate concentration. The seedlings of A. nummularia contained more oxalate than old plants whereas old shrubs of A. halimus contained more oxalate than the young seedlings. The browse of A. halimus contained more condensed and hydrolyzable tannins (1.05% and 0.67%, P < 0.0001) than A. nummularia (0.80% and 0.39%, P 0.0001), respectively. Clipping had no effect on the levels of tannic phenols, condensed and hydrolyzable tannins. Young plants of the 2 species had higher levels of condensed tannins compared to older plants. However, seedlings of A. nummularia contained significantly higher levels of condensed tannins compared to A. nummularia seedlings (1.57% and 1.47%, respectively). Atriplex halimus synthesized more oxalate, tannic phenols, condensed and hydrolyzable tannins than A. nummularia. These secondary metabolites may explain the low palatability of Atriplex halimus compared to A. nummularia.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202