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Ogoudje I Amahowe Samadori SH Biaou Armand K Natta Rodrigue O Balagueman 《Southern Forests》2018,80(2):95-103
Understanding how multiple disturbances affect species population structure is crucial for designing a better conservation strategy of threatened species. In this paper, we assessed the disturbance patterns and evaluated their effects on the population structure of Afzelia africana, in two different bioclimatic zones of the Republic of Benin. The main disturbances in the studied area included branch pruning and debarking. Individuals of medium size (20–40 cm) were mostly pruned and debarked. The percentages of pruning and debarking were similar at population level across the two studied bioclimatic zones (t = ?0.04, p = 0.96; t = 0.73, p = 0.48). Examining this at individual level, pruning was similar but debarking was higher in the Sudanian zone (12.14 ± 0.93%) than in the Sudano-Guinean zone (7.44 ± 0.88) (W = 40859, p < 0.001). Population structure was bell-shaped in the Sudanian zone regardless of the disturbance level. In contrast, in the Sudano-Guinean zone, mildly disturbed populations showed an inverse J-shaped structure, whereas those highly disturbed were bell-shaped. This underlined the climatic (dryness) and disturbance effects on the establishment and recruitment of small trees into the next life stage in tropical savanna ecosystems. Good regeneration pattern and the largest individuals were found within the protected areas, demonstrating the prominent role of protected areas for the species conservation. Therefore, we suggested that conservation efforts should be extended to populations outside the protected areas. Forestry department should establish firebreaks networks to protect small individuals and facilitate their recruitment, as well as the regulation and enforcement should be improved on the sustainable use of the species. 相似文献
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Dotché Ignace Ogoudanan Bankolé Constant B. O. Dahouda Mahamadou Biobou Rodrigue Bonou Gabriel A. Antoine-Moussiaux Nicolas Dehoux Jean-Paul Thilmant Pierre Mensah Guy Apollinaire Koutinhouin Benoît G. Youssao Abdou Karim Issaka 《Tropical animal health and production》2020,52(2):687-698
Tropical Animal Health and Production - Benin’s domestic production of pork is deficient because of the animals’ low productivity. This study aimed to evaluate the zootechnical... 相似文献
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W. Mark Ford Jane L. Rodrigue Ella L. Rowan Steven B. Castleberry Thomas M. Schuler 《Forest Ecology and Management》2010
Using coverboard arrays, we monitored woodland salamanders on the Fernow Experimental Forest in the central Appalachian Mountains, West Virginia, USA prior to and following two prescribed fires in mixed oak (Quercus spp.) forest stands. Treatments were burn plots on upper slopes or lower slopes fenced to prevent white-tailed deer (Odocoileus virginianus) herbivory or control plots that were unfenced and unburned. Most of the 7 species we observed were the mountain dusky salamander (Desmognathus ocropheaus), red-backed salamander (Plethodon cinereus) and slimy salamander (Plethodon glutinosis). Significant population responses were difficult to interpret with numerous treatment and year interactions. Results largely were equivocal. We found no change in woodland salamander assemblage prior to burning or afterwards. There were few differences in adult to juvenile ratios of salamanders among treatments. Still, a priori contrasts of mountain dusky salamanders and red-backed salamander counts corrected for detection probability were greater under coverboards in the 2 years monitored after both prescribed fires had occurred than before burning or in unburned controls. This suggests that these species responded to the reduced leaf litter on the forest floor by utilizing coverboards more. Similarly, the three predominate species of salamanders also were more numerous under coverboards in plots subjected to deer herbivory with less subsequent forest floor vegetation as compared to those burned plots that were fenced. Our observations would suggest that woodland salamanders somewhat are tolerant of two prescribed fires within close temporal proximity. However, because woodland salamanders can be significantly reduced following timber harvest, continued research is needed to fully understand impacts of fire as a pre-harvest management tool in central Appalachian forests. 相似文献
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Carbon (C) accreditation of forest development projects is one approach for sequestering atmospheric CO2, under the provisions of the Kyoto protocol. The C sequestration potential of reforested mined land is not well known. The purpose of this work was to estimate and compare the ecosystem C content in forests established on surface, coal-mined and non-mined land. We used existing tree, litter, and soil C data for fourteen mined and eight adjacent, non-mined forests in the Midwestern and Appalachian coalfields to determine the C sequestration potential of mined land reclaimed prior to the passage of the Surface Mining Control and Reclamation Act (1977). We developed statistically significant and biologically reasonable models for ecosystem C across the spectrum of site quality and stand age. On average, the highest amount of ecosystem C on mined land was sequestered in pine stands (148 Mg ha−1), followed by hardwood (130 Mg ha−1) and mixed stands (118 Mg ha−1). Non-mined hardwood stands sequestered 210 Mg C ha−1, which was about 62% higher than the average of all mined stands. Our mined land response surface models of C sequestration as a function of site quality and age explained 59, 39, and 36% of the variation of ecosystem C in mixed, pine, and hardwood stands, respectively. In pine and mixed stands, ecosystem C increased exponentially with the increase of site quality, but decreased with age. In mined hardwood stands, ecosystem C increased asymptotically with age, but it was not affected by site quality. At rotation age (60 yr), ecosystem C in mined hardwood stands was less on high quality sites, but similar for low quality sites compared to non-mined hardwood stands. The overall results indicated that the higher the original forest site quality, the less likely C sequestration potential was restored, and the greater the disparity between pre- and post-mining C sequestration stocks. 相似文献
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Rodrigue Yossa Pallab K. Sarker Emilie Proulx Vishal Saxena Marc Ekker 《Journal Of Applied Aquaculture》2013,25(2):148-153
This study aimed at a simple, rapid, reliable, practical, and non-destructive sexing technique for mature zebrafish (0.61 ± 0.011 g each). In the first experiment, 36 fish of each sex were selected on the basis of the presence of a prominent genital papilla on mature females and bred randomly. All the couples laid fertilized eggs with a mean fecundity of 304 eggs per female, for a 100% sexing accuracy. In the second experiment, 140 mature zebrafish were randomly selected and individually sexed like in the first experiment. Each fish was then dissected in order to confirm the reliability of this sexing technique through the observation of either the ovaries or the testes. Upon dissection, an accuracy of 100% was recorded. This study demonstrates that sexing mature zebrafish only on the basis of the presence of a prominent genital papilla on the mature female is a reliable technique. 相似文献
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Rodrigue Yossa Pallab K Sarker Donald M Mock Grant W Vandenberg 《Aquaculture Research》2014,45(11):1787-1797
This study was conducted to estimate the dietary biotin requirement for maximum growth of zebrafish Danio rerio. Six isonitrogenous and isocaloric purified diets containing 0.031 (biotin‐unsupplemented diet), 0.061, 0.263, 0.514, 1.741 and 2.640 mg biotin kg?1 diet were fed in triplicate tanks for a total of 12 weeks to juvenile zebrafish (initial mean body mass 0.13 ± 0.001 g). From 4 weeks of feeding, fish fed diets with ≤0.061 mg biotin kg?1 showed biotin deficiency signs, such as retarded growth and skeletal deformity, was observed on some dead fish. At the end of the study, gill disorders were observed on some fish and liver glycogen accumulation were also observed in fish fed these diets. Fish fed the biotin‐unsupplemented diet exhibited a lower final body weight, protein efficiency ratio and feed utilization than the fish fed the biotin‐supplemented diets, whereas the highest values were observed with the diet containing 0.51 mg biotin kg?1 diet (P < 0.05). A linear relationship (r2 = 0.77; P < 0.0001) was observed between whole‐body biotin content and dietary biotin level. A broken‐line analysis indicated that the optimum dietary biotin content for maximal growth expressed as final body weight is 0.51 mg kg?1 diet. 相似文献
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Mariana C. RUFINO Charles K. K. GACHENE Rodrigue V. C. DIOGO James HAWKINS Alice A. ONYANGO Ousmane M. SANOGO Ibrahim WANYAMA Gabriel YESUF David E. PELSTER 《农业科学与工程前沿(英文版)》2021,8(1):175-181
Crop-livestock farms across Africa are highly variable due to in agroecological and socioeconomic factors, the latter shaping the demand and supply of livestock products. Crop-livestock farms in Africa in the 20-first century are very different from most mixed farms elsewhere in the world. African crop-livestock farms are smaller in size, have fewer livestock, lower productivity and less dependency on imported feed than farms in most countries of Europe, the Americas and the intensive agricultural systems of Asia. This paper discusses the role African crop-livestock farms have in the broader socio-agricultural economy, and how these are likely to change adapting to pressures brought on by the intensification of food systems. This intensification implies increasing land productivity (more food per hectare), often leading to more livestock heads per farm, producing fertilized feeds in croplands and importing feed supplements from the market. This discussion includes (1) the links between crop yields, soil fertility and crop-livestock integration, (2) the increasing demand for livestock products and the land resources required to meet to this demand, and (3) the opportunities to integrate broader societal goals into the development of crop-livestock farms. There is ample room for development of crop-livestock farms in Africa, and keeping integration as part of the development will help prevent many of the mistakes and environmental problems related to the intensification of livestock production observed elsewhere in the world. This development can integrate biodiversity, climate change adaptation and mitigation to the current goals of increasing productivity and food security. The inclusion of broader goals could help farmers access the level of finance required to implement changes. 相似文献
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Rodrigue Yossa Agns Bardon‐Albaret Marcia A. Chiasson Qi Liu Jim Duston Tony Manning Tillmann J. Benfey 《Journal of the World Aquaculture Society》2019,50(5):894-907
Arctic char, Salvelinus alpinus L. is a promising candidate for aquaculture expansion in Northern Europe, Canada, and the United States because of its excellent growth at low temperature, tolerance to high rearing density, high fillet yield, and superior flesh texture and flavor. To support this industry, several breeding programs in these regions currently focus on selection for growth and delayed maturation. While the growth potential of existing strains has been improved, preharvest sexual maturation remains a problem in this industry. This article describes current knowledge on the control of preharvest maturation in Arctic char at the hatchery level through the production of single‐sex and triploid populations and during the grow‐out phase through the manipulation of photoperiod and feed intake. Research perspectives on the subject are also suggested in order to complement the efforts of ongoing breeding programs. 相似文献