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Theodor Pribulla Martin Vaňko DrahomÍr Chochol Štefan Parimucha Daniel Baluďanský 《Astrophysics and Space Science》2005,296(1-4):281-284
New photoelectric and CCD observations of the eclipsing contact binary systems V344 Lac and V1191 Cyg are presented and analyzed.
All available times of minimum light were used to study period changes of the systems and determine up-to-date ephemerides.
The orbital period of V1191 Cyg is found to be increasing at a very fast rate. The photometric elements were determined using
the new light curve, radial-velocity curve and broadening function fitting code ROCHE. 相似文献
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GOPALAKRISHNAN Ayyaru RAJKUMAR Mayalagu 孙军 PARIDA Ajay VENMATHI MARAN Balu Alagar 《中国海洋湖沼学报》2011,29(1)
The efficacy of grass carp Ctenopharyngodon idella (Cyprinidae) and weevils Neochetina spp. (Curculionidae) to control the aquatic weed, water hyacinth, is investigated in a square net cage (happas) setting at a farm in Cuddalore District, South India. This novel combination of insects and fish is found to be superior to individual treatments for controlling the weed growth within 110 d. The biomass of the weed, number of plants, percentage of flowered plants and chlorophyll contents were studied. The weed ... 相似文献
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孙军 《中国海洋湖沼学报》2011,29(1):162-166
The efficacy of grass carp Ctenopharyngodon idella (Cyprinidae) and weevils Neochetina spp. (Curculionidae) to control the aquatic weed, water hyacinth, is investigated in a square net cage (happas) setting at a farm in Cuddalore District, South India. This novel combination of insects and fish is found to be superior to individual treatments for controlling the weed growth within 110 d. The biomass of the weed, number of plants, percentage of flowered plants and chlorophyll contents were studied. The weed biomass is reduced from 5 kg (day 1) to 0.33 kg (day 110) when exposed to grass carp and weevils. The number of plants is reduced to 0.75 in grass carp and weevil exposed happas, while it is 741.5 in the control. The mean number of leaves per plant is also reduced. In addition, the chlorophyll a and b are significantly reduced in happas exposed to the combination of fish and insects when compared to the other treatments. Based on the results of this study, we consider the combined use of grass carp and weevils to be more efficient and sustainable for managing water hyacinths than the use of these organisms individually. 相似文献
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Biodiversity Conservation in the REDD 总被引:1,自引:0,他引:1
Gary D Paoli Philip L Wells Erik Meijaard Matthew J Struebig Andrew J Marshall Krystof Obidzinski Aseng Tan Andjar Rafiastanto Betsy Yaap JW Ferry Slik Alexandra Morel Balu Perumal Niels Wielaard Simon Husson Laura D'Arcy 《Carbon balance and management》2010,5(1):1-9
Background
Forests occur across diverse biomes, each of which shows a specific composition of plant communities associated with the particular climate regimes. Predicted future climate change will have impacts on the vulnerability and productivity of forests; in some regions higher temperatures will extend the growing season and thus improve forest productivity, while changed annual precipitation patterns may show disadvantageous effects in areas, where water availability is restricted. While adaptation of forests to predicted future climate scenarios has been intensively studied, less attention was paid to mitigation strategies such as the introduction of tree species well adapted to changing environmental conditions.Results
We simulated the development of managed forest ecosystems in Germany for the time period between 2000 and 2100 under different forest management regimes and climate change scenarios. The management regimes reflect different rotation periods, harvesting intensities and species selection for reforestations. The climate change scenarios were taken from the IPCC's Special Report on Emission Scenarios (SRES). We used the scenarios A1B (rapid and successful economic development) and B1 (high level of environmental and social consciousness combined with a globally coherent approach to a more sustainable development). Our results indicate that the effects of different climate change scenarios on the future productivity and species composition of German forests are minor compared to the effects of forest management.Conclusions
The inherent natural adaptive capacity of forest ecosystems to changing environmental conditions is limited by the long life time of trees. Planting of adapted species and forest management will reduce the impact of predicted future climate change on forests. 相似文献
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