Knowledge on the home range size of a species or population is important for understanding its behavioral and social ecology and improving the effectiveness of conservation strategies. We studied the home range size o...Knowledge on the home range size of a species or population is important for understanding its behavioral and social ecology and improving the effectiveness of conservation strategies. We studied the home range size of two different-sized groups of golden snub-nosed monkeys(Rhinopithecus roxellana) in Shennongjia, China. The larger group(236 individuals)had a home range of 22.5 km2 from September2007 to July 2008, whereas the smaller group(62 individuals) occupied a home range of 12.4 km2 from November 2008 to July 2009. Both groups exhibited considerable seasonal variation in their home range size, which was likely due to seasonal changes in food availability and distribution. The home range in any given season(winter, spring, summer, or winter+spring+summer) of the larger group was larger than that of the smaller group. As the two groups were studied in the same area, with the confounding effects of food availability thus minimized, the positive relationship between home range size and group size suggested that scramble feeding competition increased within the larger group.展开更多
Background: In rumen fermentation, fumaric acid(FA) could competitively utilize hydrogen with methanogenesis to enhance propionate production and suppress methane emission, but both effects were diet-dependent. This s...Background: In rumen fermentation, fumaric acid(FA) could competitively utilize hydrogen with methanogenesis to enhance propionate production and suppress methane emission, but both effects were diet-dependent. This study aimed to explore the effects of FA supplementation on methanogenesis and rumen fermentation in goats fed diets varying in forage and concentrate particle size.Methods: Four rumen-cannulated goats were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments: low or high ratio of forage particle size: concentrate particle size(Fps:Cps), without or with FA supplementation(24 g/d). Fps:Cps was higher in the diet with chopped alfalfa hay plus ground corn than in that with ground alfalfa hay plus crushed corn.Results: Both increasing dietary Fps:Cps and FA supplementation shifted ruminal volatile fatty acid(VFA) patterns toward more propionate and less acetate in goats. An interaction between dietary Fps:Cps and FA supplementation was observed for the ratio of acetate to propionate(A:P), which was more predominant when FA was supplemented in the low-Fps:Cps diet. Methane production was reduced by FA, and the reduction was larger in the low-Fps:Cps diet(31.72%) than in the high-Fps:Cps diet(17.91%). Fumaric acid decreased ruminal total VFA concentration and increased ruminal p H. No difference was found in ruminal DM degradation of concentrate or alfalfa hay by dietary Fps:Cps or FA. Goats presented a lower ruminal methanogen abundance with FA supplementation and a higher B. fibrisolvens abundance with high dietary Fps:Cps.Conclusions: Adjusting dietary Fps:Cps is an alternative dietary model for studying diet-dependent effects without changing dietary chemical composition. Fumaric acid supplementation in the low-Fps:Cps diet showed greater responses in methane mitigation and propionate increase.展开更多
The simultaneous nitrification and denitrification in step-feeding biological nitrogen removal process were investigated under different influent substrate concentrations and aeration flow rates. Biological occurrence...The simultaneous nitrification and denitrification in step-feeding biological nitrogen removal process were investigated under different influent substrate concentrations and aeration flow rates. Biological occurrence of simultaneous nitrification and denitrification was verified in the aspect of nitrogen mass balance and alkalinity. The experimental results also showed that there was a distinct linear relationship between simultaneous nitrification and denitrification and DO concentration under the conditions of low and high aeration flow rate. In each experimental run the floc sizes of activated sludge were also measured and the results showed that simultaneous nitrification and denitrification could occur with very small size of floc.展开更多
潜蝇姬小蜂属Diglyphus寄生蜂是潜叶蝇类害虫的重要天敌。本文对其种类、分布、田间发生和优势度、优势种的控害特性和生态适应性,以及优势种的人工繁殖和田间应用等进行总结和展望,以期为更好地应用该属寄生蜂防控我国潜叶蝇的研究和...潜蝇姬小蜂属Diglyphus寄生蜂是潜叶蝇类害虫的重要天敌。本文对其种类、分布、田间发生和优势度、优势种的控害特性和生态适应性,以及优势种的人工繁殖和田间应用等进行总结和展望,以期为更好地应用该属寄生蜂防控我国潜叶蝇的研究和应用提供指导。迄今已鉴定该属寄生蜂36种,全为抑性外寄生蜂,其中针对豌豆潜蝇姬小蜂D.isaea、贝氏潜蝇姬小蜂D.begini和中带潜蝇姬小蜂D.intermedius的研究较多。雌蜂不仅可通过繁殖型的寄生方式而且还可通过非繁殖型方式(取食寄主和产卵器插入直接杀死)致死寄主。雌蜂偏好寄生大个体寄主和取食相对较小个体的寄主,且雌蜂对寄主幼虫的偏好具有"寄主大小依赖型性别分配"现象(host-size-dependent sex allocation)。从温度适应范围和控害潜力首推为豌豆潜蝇姬小蜂。优势种的规模饲养技术已经被研发并得到了较广泛的田间应用。未来研究可主要集中于:(1)加强优势种尤其是温度适应范围广或较为耐热的种群或地理品系的研究,以增加对三叶草斑潜蝇Liriomyza trifolii和美洲斑潜蝇L.sativae的控效;(2)加强雌蜂寄主取食行为特性及其生理机制的研究,以更高效利用;(3)因地制宜研发规模化饲养技术和释放技术;(4)加强潜蝇姬小蜂同其他潜叶蝇寄生蜂的协同控害及竞争共存机制的研究,已提升对潜叶蝇的生防控制效果。展开更多
基金supported by the Hubei Provincial Key Laboratory for Conservation Biology of Snub-nosed Monkeys,Scientific Research Grant for Youth Scholars from the University of Chinese Academy of Sciences,L.S.B.Leakey Foundation,and Primate Conservation Inc.
文摘Knowledge on the home range size of a species or population is important for understanding its behavioral and social ecology and improving the effectiveness of conservation strategies. We studied the home range size of two different-sized groups of golden snub-nosed monkeys(Rhinopithecus roxellana) in Shennongjia, China. The larger group(236 individuals)had a home range of 22.5 km2 from September2007 to July 2008, whereas the smaller group(62 individuals) occupied a home range of 12.4 km2 from November 2008 to July 2009. Both groups exhibited considerable seasonal variation in their home range size, which was likely due to seasonal changes in food availability and distribution. The home range in any given season(winter, spring, summer, or winter+spring+summer) of the larger group was larger than that of the smaller group. As the two groups were studied in the same area, with the confounding effects of food availability thus minimized, the positive relationship between home range size and group size suggested that scramble feeding competition increased within the larger group.
基金supported by the National Key Research and Development Program of China(2017YFD0500500)Key Research and Development Program of Shaanxi Province(2017ZDXM-NY-086)
文摘Background: In rumen fermentation, fumaric acid(FA) could competitively utilize hydrogen with methanogenesis to enhance propionate production and suppress methane emission, but both effects were diet-dependent. This study aimed to explore the effects of FA supplementation on methanogenesis and rumen fermentation in goats fed diets varying in forage and concentrate particle size.Methods: Four rumen-cannulated goats were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments: low or high ratio of forage particle size: concentrate particle size(Fps:Cps), without or with FA supplementation(24 g/d). Fps:Cps was higher in the diet with chopped alfalfa hay plus ground corn than in that with ground alfalfa hay plus crushed corn.Results: Both increasing dietary Fps:Cps and FA supplementation shifted ruminal volatile fatty acid(VFA) patterns toward more propionate and less acetate in goats. An interaction between dietary Fps:Cps and FA supplementation was observed for the ratio of acetate to propionate(A:P), which was more predominant when FA was supplemented in the low-Fps:Cps diet. Methane production was reduced by FA, and the reduction was larger in the low-Fps:Cps diet(31.72%) than in the high-Fps:Cps diet(17.91%). Fumaric acid decreased ruminal total VFA concentration and increased ruminal p H. No difference was found in ruminal DM degradation of concentrate or alfalfa hay by dietary Fps:Cps or FA. Goats presented a lower ruminal methanogen abundance with FA supplementation and a higher B. fibrisolvens abundance with high dietary Fps:Cps.Conclusions: Adjusting dietary Fps:Cps is an alternative dietary model for studying diet-dependent effects without changing dietary chemical composition. Fumaric acid supplementation in the low-Fps:Cps diet showed greater responses in methane mitigation and propionate increase.
基金Project supported by the Key International Cooperative Program of NSFC(No. 50521140075)the Hi-Tech Research and Development Program(863)of China(No. 2004AA601020)the Attached Projects of"863"Project of Beijing Municipal Science and Technology(No.20005186040421).
文摘The simultaneous nitrification and denitrification in step-feeding biological nitrogen removal process were investigated under different influent substrate concentrations and aeration flow rates. Biological occurrence of simultaneous nitrification and denitrification was verified in the aspect of nitrogen mass balance and alkalinity. The experimental results also showed that there was a distinct linear relationship between simultaneous nitrification and denitrification and DO concentration under the conditions of low and high aeration flow rate. In each experimental run the floc sizes of activated sludge were also measured and the results showed that simultaneous nitrification and denitrification could occur with very small size of floc.
文摘潜蝇姬小蜂属Diglyphus寄生蜂是潜叶蝇类害虫的重要天敌。本文对其种类、分布、田间发生和优势度、优势种的控害特性和生态适应性,以及优势种的人工繁殖和田间应用等进行总结和展望,以期为更好地应用该属寄生蜂防控我国潜叶蝇的研究和应用提供指导。迄今已鉴定该属寄生蜂36种,全为抑性外寄生蜂,其中针对豌豆潜蝇姬小蜂D.isaea、贝氏潜蝇姬小蜂D.begini和中带潜蝇姬小蜂D.intermedius的研究较多。雌蜂不仅可通过繁殖型的寄生方式而且还可通过非繁殖型方式(取食寄主和产卵器插入直接杀死)致死寄主。雌蜂偏好寄生大个体寄主和取食相对较小个体的寄主,且雌蜂对寄主幼虫的偏好具有"寄主大小依赖型性别分配"现象(host-size-dependent sex allocation)。从温度适应范围和控害潜力首推为豌豆潜蝇姬小蜂。优势种的规模饲养技术已经被研发并得到了较广泛的田间应用。未来研究可主要集中于:(1)加强优势种尤其是温度适应范围广或较为耐热的种群或地理品系的研究,以增加对三叶草斑潜蝇Liriomyza trifolii和美洲斑潜蝇L.sativae的控效;(2)加强雌蜂寄主取食行为特性及其生理机制的研究,以更高效利用;(3)因地制宜研发规模化饲养技术和释放技术;(4)加强潜蝇姬小蜂同其他潜叶蝇寄生蜂的协同控害及竞争共存机制的研究,已提升对潜叶蝇的生防控制效果。
