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31.
Traditional agroforestry systems and biodiversity conservation in Benin (West Africa) 总被引:1,自引:1,他引:0
Vodouhe G. Fifanou Coulibaly Ousmane Biaou Gauthier Sinsin Brice 《Agroforestry Systems》2011,82(1):1-13
In the past, the conservation of biodiversity has been mostly understood in terms of the management of protected areas and
natural forests, ignoring the possible role of farm areas and the ways through which rural communities have promoted biodiversity
in their subsistence agricultural production systems. The present study focused on the floristic diversity within traditional
agroforestry parkland systems around the Pendjari Biosphere Reserve in Benin and showed the diversity of tree species in the
area as well as socio-economic factors which affect the practice of this farming system. We used questionnaires and interviewed
a total of 118 households to collect data. Respondents were interviewed on their farms and during the interview; we inventoried
the number of tree on the farm and determined the farm size. Twenty-one tree species belonging to 14 botanical families were
recorded during the surveys and the average stand density of the woody component of farmlands was 7.97 ± 5.43 stems/ha. A
number of both native and exotic tree species occurred in the parkland agroforestry systems with dominance of indigenous tree
species. Species richness varied with the size of household where households with small land holding conserve more tree species
in their field than households with large land holdings. 64% of households surveyed were making deliberate efforts to plant
tree species on their farmlands. The most important reasons which determined household ambitions to conserve woody species
on farmland were tree products contribution to food and medicine. Results also showed that respondents who noticed that trees
were decreasing in the wild conserve more tree species on their farmlands. This research highlights the role of traditional
agroforestry practices to support tree species richness and provides evidence of the farms’ role as biodiversity reservoirs. 相似文献
32.
33.
Owczarek-Fendor A De Meulenaer B Scholl G Adams A Van Lancker F Eppe G De Pauw E Scippo ML De Kimpe N 《Journal of agricultural and food chemistry》2011,59(6):2368-2376
The formation of furan upon sterilization of a lipid-containing starch gel was investigated in the presence of various antioxidants, namely, α-tocopherol, β-carotene, and ascorbic acid, with and without proteins. Results indicated that α-tocopherol did not significantly influence furan formation from oxidized lipids. β-Carotene, suggested previously to be a furan precursor itself, did influence the generation of furan in a concentration-dependent manner, although to a limited extent. Surprisingly, the presence of lipids seemed to limit the furan generation from β-carotene. Interestingly, the addition of ascorbic acid to the emulsions containing soybean or sunflower oils considerably enhanced the formation of furan from these oils. This was also the case when fresh oils were applied, shown previously to be nearly unable to generate furan. This observation can be explained by an intensified ascorbic acid degradation stimulated by the presence of lipids. 相似文献
34.
J T Goras A R Gauthier 《Journal of the Association of Official Analytical Chemists》1985,68(3):598-601
A liquid chromatographic (LC) method is proposed for measuring 0.485-0.970% morantel tartrate in cattle feeds. The drug is leached from feed, diluted, separated from interfering substances on a silica column, and measured in the effluent stream by 313 nm spectrophotometric detection. Two potential degradation products, i.e., cis-isomer of morantel tartrate and N-(3-methylaminopropyl)-trans-3-(3-methyl-2-thienyl)acrylamide, and a related anthelmintic, i.e., pyrantel tartrate, do not interfere. Average recovery of drug from liquid spiked samples and laboratory blends was 98-100% with a maximum coefficient of variation (CV) of 2.3%. Results for pelleted and crumbled commercial scale feeds ranged from 94 to 102% of label claim, with a maximum CV of 1.5%. 相似文献
35.
Nicolas Mansuy Yan Boulanger Aurélie Terrier Sylvie Gauthier André Robitaille Yves Bergeron 《Landscape Ecology》2014,29(7):1157-1170
The characterization of the fire regime in the boreal forest rarely considers spatial attributes other than fire size. This study investigates the spatial attributes of fires using the physiography of the landscape as a spatial constraint at a regional scale. Using the Canadian National Fire Database, the size, shape, orientation and eccentricity were assessed for 1,136 fires between 1970 and 2010 in Quebec’s boreal forest and were summarized by ecodistrict. These spatial metrics were used to cluster 33 ecodistricts into homogeneous fire zones and then to determine which environmental variables (climate, topography, hydrography, and surficial deposits) influence the spatial attributes of fires. Analyses showed that 28 out of 33 ecodistricts belonging to a given fire zone were spatially contiguous, suggesting that factors driving the spatial attributes of fire are acting at a regional scale. Indeed, the orientation and size of fires vary significantly among the zones and are driven by the spatial orientation of the landscape and the seasonal regional climate. In some zones, prevailing winds during periods conducive to fire events parallel to the orientation of the landscape may favour the occurrence of very large fires (>100,000 ha). Conversely, an orientation of the landscape opposite to the prevailing winds may act as a natural firebreak and limit the fire size and orientation. This study highlights the need to consider the synergistic relationship between the landscape spatial patterns and the climate regime over the spatial attributes of fire at supra-regional scale. Further scale-dependant studies are needed to improve our understanding of the spatial factors controlling the spatial attributes of fire. 相似文献
36.
37.
H.L. Xu L. Gauthier A. Gosselin 《The Journal of Horticultural Science and Biotechnology》2013,88(5):821-832
SUMMARYGreenhouse tomato plants (Lycopersicon esculentum Mill. cv. Capello) were grown in a peal-moss based substrate and supplied with nutrient solutions of high (4.5 mS cm-1) or low (2.3 mS cm-1) electrical conductivity (EC) and under high (95 ± 5%) or low (55 ± 8% of capillary capacity) soil water content, to elucidate how EC and soil water status affect plant photosynthesis and related physiological processes. Two weeks after beginning the treatments, photosynthesis (Pn) was measured during changes of photo-synthetic photon flux (PPF) from 0 to 1200 u.mol m-2 s-1 using a gas exchange method. The rectangular hyperbolic model (Pn = Pmax KI (1-KI)-2 -r) provided a good fit for the photosynthetic light-response curve. High EC treatment changed the curve by increasing the initial slope (quantum yield) and decreasing photosynthetic capacity at high PPF. However, soil water deficit not only decreased the photosynthetic capacity, but also decreased quantum use efficiency. Depression of Pn was attributed to decreased stomatal (gs) and mesophyll (gm) conductances, but gs was depressed more than gm. The ratio of gm/(gm + gs), an indicator of water use efficiency and a measure of relative control of Pn by carboxylation and C02 supply, was higher for high-EC treated plants. Chlorophyll content was increased by high EC treatment, and was consistent with quantum yield. Leaf water potential was decreased by high EC and/or low soil water content and the decreases in leaf water potential ultimately accounted for the Pn depressions. The effects of high EC and soil water deficit were additive on photosynthesis and most related physiological processes. 相似文献
38.
Frank D Gauthier A Bergeron R 《The Canadian veterinary journal. La revue veterinaire canadienne》2006,47(11):1102-1108
The purpose of this explorative study was, first, to document changes in physiological parameters and behavior observed in dogs following ground transport and, second, to measure the effects on the above variables of a short-term administration of clomipramine, anecdotally already prescribed in private veterinary practice to reduce fear, anxiety, or both. Twenty-four beagles were randomly allocated to either clomipramine (2 mg/kg, q12h for 7 d) or placebo treatment, and then transported 3 times in a truck for 1 hour. Physiological parameters (cortisol, neutrophil:lymphocyte (N:L) ratio, heart rate) and behavior were recorded and analyzed. Clomipramine significantly reduced plasma cortisol (P < 0.05) following transport and tended (P = 0.07) to reduce N:L ratio. Clomipramine tended to only reduce "moving and panting" and drooling. Short-term administration of clomipramine appears to slightly reduce fear, anxiety, or both during transport. More research is needed to confirm the efficacy of this treatment and the appropriate dosage. 相似文献
39.
Robert C. Morrissey Martin-Michel Gauthier John A. Kershaw Jr. Douglass F. Jacobs John R. Seifert Burnell C. Fischer 《Forest Ecology and Management》2009
The role of lianas (woody vines) in the development and diversity of both tropical and temperate forests under differing management scenarios has not been thoroughly explored. We examined changes in grapevine (Vitis spp.) densities over time in clearcut stands as influenced by manual tending, physiography, and host tree associations. We used data from long-term studies on 66 clearcut stands dominated by temperate deciduous forest tree species on the Hoosier National Forest in south-central Indiana, USA. Fourteen of the stands had grapevines removed manually, approximately during the stem exclusion stage of development. Grapevine densities steadily increased from age 5 until age 15, which coincides with the period of stem exclusion of these stands. Subsequent grapevine mortality may have been related to light competition. Manually treated stands had similar grapevine densities as untreated stands after 20 years across sites, and it appeared that only on the most xeric area was the grapevine treatment effective in reducing grapevine densities. During early stand development, ranging from ages 5 to 17, grapevine density was strongly related to slope position, but as stands developed through the stem exclusion stage, aspect emerged as a stronger factor influencing grapevine density. Black cherry (Prunus serotina Ehrh.), walnut (Juglans spp.), and elm (Ulmus spp.) were the most common grapevine host trees under both treated and untreated scenarios, which may be associated with the crown architecture of these species. Results suggest lianas play a critical role in the early development of disturbed forest sites in temperate deciduous forests. With concerns that lianas are increasing in abundance and distribution in these forest types, understanding their role in forest dynamics, such as host tree associations at different stages of development, competition dynamics on different sites and corresponding influences on tree growth, species composition, and diversity, will be critical to decision-making processes in achieving desired management goals in the future. 相似文献
40.
Mathieu Raillard Julien Michaut-Castrillo Damien Spreux Olivier Gauthier Gwenola Touzot-Jourde Delphine Holopherne-Doran 《Veterinary anaesthesia and analgesia》2017,44(1):17-27