84 research outputs found

    Uses and Knowledge of Plant Species by Mongolian Herders in the Gobi Desert and Identification of Species of Interest for Planting

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    In Central Asia, many projects propose to establish single-species saxaul (Haloxylon ammodendron (C.A. Meyer) Bunge) plantations. An ethnobotanical survey was carried out among herders in Ulaanbadrakh, in the Dornogobi province, and herders in Gurvansaikhan, in the Dundgobi province in the Gobi Desert (Mongolia). The aim of this survey is to verify the interest of saxaul for the local populations, and to identify other woody species of interest for planting. Herders were questioned about the use of plant species from the Gobi grazing lands: livestock feed, human food, and then about plant species non-eaten by livestock and those that could be toxic to them. A total of 75 species and 413 uses related to these species were cited. We retained the species cited by at least 25% of the herders: 8 species of interest were selected, then sorted according to the number of associated positive uses, while focusing on the species cited in Ulaanbadrakh (area of interest in the Dornogobi). Saxaul appears to be the most numerous woody species for the herders and their livestock. Three other woody species of interest have also been identified. These results show that there is a high diversity of plant species used. It would be interesting to investigate the interest of a multi-species plantation for herders and their livestock in future surveys

    Ceased grazing management changes the ecosystem services of semi-natural grasslands

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    Understanding how drivers of change affect ecosystem services (ES) is of great importance. Indicators of ES can be developed based on biophysical measures and be used to investigate the service flow from ecosystems to socio-ecological systems. However, the ES concept is multivariate and the use of normalized composite indicators reduces complexity and facilitates communication between science and policy. The aim of this study is to analyze how land use change affects ES and species richness and how the effects are modified by environmental factors by using composite indicators based on biophysical indicators. Using multivariate and regression analyses, we analyze the effect of grazing management abandonment in semi-natural grasslands in Norway on six ES: nutrient cycling, pollination, forage quality, aesthetics and global and regional climate regulation in addition to species richness along soil and climate gradients. Nutrient cycling, forage quality, regional climate regulation, aesthetics and species richness are larger in managed compared to abandoned grasslands. There are trade-offs among ES as different management strategies provide various ES and these trade-offs vary along environmental gradients. Management policies that aim to conserve ES need to have conservation goals that are context dependent, should recognize ES trade-offs and be adapted to local conditions

    Modelling the hydrological behaviour of a coffee agroforestry basin in Costa Rica

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    UMR LISAH, Equipe Eau et Polluants en Bassins VersantsThe profitability of hydropower in Costa Rica is affected by soil erosion and sedimentation in dam reservoirs, which are in turn influenced by land use, infiltration and aquifer interactions with surface water. In order to foster the provision and payment for Hydrological Environmental Services (HES), a quantitative assessment of the impact of specific land uses on the functioning of drainage-basins is required. The present paper aims to study the water balance partitioning in a volcanic coffee agroforestry microbasin (1 km(2), steep slopes) in Costa Rica, as a first step towards evaluating sediment or contaminant loads. The main hydrological processes were monitored during one year, using flume, eddy-covariance flux tower, soil water profiles and piezometers. A new Hydro-SVAT lumped model is proposed, that balances SVAT (Soil Vegetation Atmosphere Transfer) and basin-reservoir routines. The purpose of such a coupling was to achieve a trade-off between the expected performance of ecophysiological and hydrological models, which are often employed separately and at different spatial scales, either the plot or the basin. The calibration of the model to perform streamflow yielded a Nash-Sutcliffe (NS) coefficient equal to 0.89 for the year 2009, while the validation of the water balance partitioning was consistent with the independent measurements of actual evapotranspiration (R-2 = 0.79, energy balance closed independently), soil water content (R-2 = 0.35) and water table level (R-2 = 0.84). Eight months of data from 2010 were used to validate modelled streamflow, resulting in a NS = 0.75. An uncertainty analysis showed that the streamflow modelling was precise for nearly every time step, while a sensitivity analysis revealed which parameters mostly affected model precision, depending on the season. It was observed that 64% of the incident rainfall R flowed out of the basin as streamflow and 25% as evapotranspiration, while the remaining 11% is probably explained by deep percolation, measurement errors and/or inter-annual changes in soil and aquifer water stocks. The model indicated an interception loss equal to 4% of R, a surface runoff of 4% and an infiltration component of 92%. The modelled streamflow was constituted by 87% of baseflow originating from the aquifer, 7% of subsurface non-saturated runoff and 6% of surface runoff. Given the low surface runoff observed under the current physical conditions (andisol) and management practices (no tillage, planted trees, bare soil kept by weeding), this agroforestry system on a volcanic soil demonstrated potential to provide valuable HES, such as a reduced superficial displacement- capacity for fertilizers, pesticides and sediments, as well as a streamflow regulation function provided by the highly efficient mechanisms of aquifer recharge and discharge. The proposed combination of experimentation and modelling across ecophysiological and hydrological approaches proved to be useful to account for the behaviour of a given basin, so that it can be applied to compare HES provision for different regions or management alternatives

    The mitochondrial DNA content of cumulus cells may help predict embryo implantation

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    PURPOSE: The quantification of mtDNA in cumulus granulosa cells (CGCs) surrounding an oocyte has been positively linked with morphological embryonic quality. In the present study, we evaluated the link between the amount of mtDNA in CGCs surrounding an oocyte and the chances for the corresponding embryo of implanting and leading to an ongoing pregnancy. METHODS: This is an observational study, performed on 84 oocyte-cumulus-complexes (OCCs) having led to the replacement of an embryo in the maternal uterus, retrieved from 71 patients undergoing IVF with intracytoplasmic sperm. The OCCs were classified in two groups, one including 26 OCCs having led to an implanted embryo and the other including 58 OCCs having led to a non-implanted embryo. The average mtDNA content of CGCs was assessed by using a quantitative real-time PCR technique. RESULTS: Significantly higher mtDNA copy numbers in CGCs were associated with implanted embryos than with non-implanted embryos (mean 215 [sd 375] and 59 [sd 72], respectively; p < 10). Multivariate analysis, taking into account the women\u27s age, the embryo quality, and the AMH level, suggests an independent relationship between the mtDNA content of CGCs and the potential of embryo implantation. CONCLUSION: During in vitro fertilization (IVF) procedures, the probability of the implantation of the embryo appears to be closely correlated to the mtDNA copy numbers in the CGCs. Our results highlight the interest of mtDNA quantification in GCGs as a biomarker of the potential of embryo implantation

    Early Cretaceous vegetation and climate change at high latitude: Palynological evidence from Isachsen Formation, Arctic Canada

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    Quantitative palynology of the marginal marine and deltaic-fluvial Isachsen Formation of the Sverdrup Basin, Canadian Arctic, provides insight into high latitude climate during much of the Early Cretaceous (Valanginian to early Aptian). Detrended Correspondence Analysis of main pollen and spore taxa is used to derive three ecological groupings influenced by moisture and disturbance based on the botanical affinities of palynomorphs: 1) a mixed coniferous assemblage containing both lowland and upland components; 2) a conifer-filicopsid community that likely grew in dynamic lowland habitats; and, 3) a mature dry lowland community composed of Cheirolepidiaceans. Stratigraphic changes in the relative abundance of pollen and spore taxa reflect climate variability in this polar region during the ~20 Mya history of the Isachsen Formation. The late Valanginian was relatively cool and moist and promoted lowland conifer-filicopsid communities. Warming in the Hauterivian resulted in the expansion coniferous communities in well-drained or arid hinterlands. A return to relatively cool and moist conditions in the Barremian resulted in the expansion of mixed lowland communities. This work demonstrates the utility of a multivariate statistical approach to palynology to provide insight into the composition and dynamics of ecosystems and climate of high latitude regions during the Early Cretaceous

    Agroforesterie et services écosystémiques en zone tropicale

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    Respectueux de l’environnement et garantissant une sĂ©curitĂ© alimentaire soutenue par la diversification des productions et des revenus qu’ils procurent, les systĂšmes agroforestiers apparaissent comme un modĂšle prometteur d’agriculture durable dans les pays du Sud les plus vulnĂ©rables aux changements globaux. Cependant, ces systĂšmes agroforestiers ne peuvent ĂȘtre optimisĂ©s qu’à condition de mieux comprendre et de mieux maĂźtriser les facteurs de leurs productions. L’ouvrage prĂ©sente un ensemble de connaissances rĂ©centes sur les mĂ©canismes biophysiques et socio-Ă©conomiques qui sous-tendent le fonctionnement et la dynamique des systĂšmes agroforestiers. Il concerne, d’une part les systĂšmes agroforestiers Ă  base de cultures pĂ©rennes, telles que cacaoyers et cafĂ©iers, de rĂ©gions tropicales humides en AmĂ©rique du Sud, en Afrique de l’Est et du Centre, d’autre part les parcs arborĂ©s et arbustifs Ă  base de cultures vivriĂšres, principalement de cĂ©rĂ©ales, de la rĂ©gion semi-aride subsaharienne d’Afrique de l’Ouest. Il synthĂ©tise les derniĂšres avancĂ©es acquises grĂące Ă  plusieurs projets associant le Cirad, l’IRD et leurs partenaires du Sud qui ont Ă©tĂ© conduits entre 2012 et 2016 dans ces rĂ©gions. L’ensemble de ces projets s’articulent autour des dynamiques des systĂšmes agroforestiers et des compromis entre les services de production et les autres services socio-Ă©cosystĂ©miques que ces systĂšmes fournissent
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