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Mouldi Gamoun 《Land Degradation \u0026amp; Development》2016,27(3):738-747
Desert rangelands are characterised by low and highly variable rainfall regime, low forage production and high heterogeneity in the distribution of natural resources. This study was carried out in the desert rangelands of Tunisia to evaluate the response of different rangelands to annual rainfall in terms of aboveground net primary production (ANPP) and rain use efficiency over a 10‐year period (2003–2012). In general, ANPP values were relatively low (123 kg DM ha−1 y−1) but would tend to increase with increasing annual rainfall for all rangeland types. The highest value of ANPP was observed from Stipagrostis pungens and Hammada shmittiana communities (sandy‐soil) during the wet year 2011. In contrast, rain use efficiency tends to decline with the highest annual rainfall and varies among rangeland types and with an average of 1·9 kg DM ha−1 mm−1 y−1. Rain use efficiency tended to be higher during dry years and lower during wet years and tended to be higher on S. pungens and H. shmittiana (sandy‐soils) and lower on Helianthemum kahiricum (loamy soils). Therefore, understanding how rainfall affects productivity in rangelands is critical for predicting the impact of land degradation on the functioning of these ecosystems. It can be used to explain production decline associated with desertification as well as to assess rangeland conditions. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Mouldi GAMOUN 《干旱区科学》2014,6(3):324-333
@Mouldi GAMOUN$Laboratory of Range Ecology, Arid Regions Institute (IRA)!Medenine 4119, Tunisia 相似文献
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A survey of chemical and nutritional characteristics of halophytes plants used by camels in Southern Tunisia 总被引:1,自引:1,他引:0
Laudadio V Tufarelli V Dario M Hammadi M Seddik MM Lacalandra GM Dario C 《Tropical animal health and production》2009,41(2):209-215
The camel (Camelus dromedarius) is well adapted to the utilization of vegetation of low nutritional value in its natural habitat zone, thanks to its aptitude
to vary food and to search plants that are rich in water content and that can make up for its nutritional deficits, particularly
as concerns mineral elements. Therefore, a survey was carried out to determine camels pasture quality, dietary preference
and to characterize the chemical characteristics and nutritional value of different halophytes plants in a region of Southern
Tunisia during spring season. Laboratory analysis were conducted on fourteen vegetable species appertained to seven different
botanical families: Chenopodiaceae, Graminaceae, Tamaricaceae, Zygophyllaceae, Asteraceae, Frankeniaceae and Plumbaginaceae. Data obtained indicate an high variability of nutritional content of halophytes plants preferred by camels, specially for
dry matter, crude protein, fiber fractions, ash and mineral elements. 相似文献
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Hmissi Imen Bargaz Adnane Bouraoui Manel Yassine Mabrouk Mouldi Saidi 《Journal of plant nutrition》2015,38(11):1656-1671
The use of phosphate-solubilising bacteria as inoculants increases plant phosphorus (P) uptake and thus crop yield. Strains from the genus Mesorhizobium are among the most powerful phosphate solubilizing microorganisms. In order to study efficiency in P uptake and N2 fixation in chickpea (Cicer aritenium), forty-two rhizobia strains natively from Tunisian soils were studied in symbiosis with the chickpea variety “Béja1” which is frequently cultivated in Tunisia. Plants were inoculated separately with these strains under controlled conditions in perlite under two sources of P i.e. soluble (KH2PO4) and insoluble P (Ca2HPO4). At flowering stage, growth, nodulation, P uptake and N2 fixation were assessed in all symbiotic combinations. The results showed that the S27 strain efficiently mobilized P into plants, observed as a significant increase of plant P content when insoluble P (Ca2HPO4) was supplied to the soil. This was associated with a significant increase in plant biomass, nodule number and N content under insoluble P conditions. Additionally, inoculation with the Mesorhizobium strain S27 significantly increased the root acid phosphatase activity under insoluble P. This study also shows significant correlations found between plant P content and acid phosphatase activity under low P conditions which may highlight the contribution of acid phosphatases in increasing P use efficiency. A field experiment also showed that most of the chickpea analyzed parameters were improved when plants inoculated with two selected rhizobia strains (S26 and S27) and supplied with P2O5. Overall, these findings postulate that rhizobial inoculation should not only be based on the effectiveness of strains regarding N fixation, but also to other traits such as P solubilisation potential. 相似文献
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