In this study, we explore the feasibility of optimizing ecosystem photosynthetic and respiratory parameters from the seasonal variation of the net carbon flux. An optimization scheme is proposed to estimate two key pa...In this study, we explore the feasibility of optimizing ecosystem photosynthetic and respiratory parameters from the seasonal variation of the net carbon flux. An optimization scheme is proposed to estimate two key parameters （V2max and Q10） by exploiting the seasonal variation in the net ecosystem carbon flux retrieved by an atmospheric inversion system. This scheme is implemented to estimate V25max and Q10 of the boreal ecosystem productivity simulator （BEPS） to improve its NEP simulation in the boreal North American region. Then, in situ NEE observations at six eddy covariance sites are used to evaluate the NEE simulations from BEPS with initial and optimized parameters. The results show that the performance of the optimized BEPS is superior to that of the BEPS with the default parameter values. These results implicate that it is possible to optimize ecosystem model parameters by different sensitivities of V25max and Q10 during growing and non-growing seasons through atmospheric inversion or data assimilation techniques.展开更多
Animal habitat-use patterns cannot be isolated from scale issues. Consequently, multi-scale studies provide a complete characterization of ecological patterns that can further explain the observed variation. Liolaemus...Animal habitat-use patterns cannot be isolated from scale issues. Consequently, multi-scale studies provide a complete characterization of ecological patterns that can further explain the observed variation. Liolaemus constitutes the world＇s second most speciose lizard genus. In this study, we assessed the relationships between home range size and environmental variables at 3 different spatial scales. The study at a local and regional scale was focused on the habitat specialist Liolaemus multimaculatus. The lizard＇s home range was calculated using the minimum convex polygon method in populations from grassland sites of the coastal sand dunes of the Argentinean Pampas under 2 different conditions, with or without forestations of Acacia Iongifolia. On the other hand, at a geographical scale we considered the evolutionary implications of 20 species of Liolaemus. Home range size, phylogeny, ecological, environmental, and climatic data were ob- tained from the literature and remote sensing. L. multimaculatus home range varied from 12.66 to 570.00 m. Regionally, this species had smaller home ranges in forested habitats （X： 94.02 m2） com- pared with the non-forested sites （X： 219.78m2）. Habitat structure, vegetation types, and food availability would explain the space use at finer scales. When the 20 species of Liolaernus were considered, high mean air temperature and broad thermal amplitudes showed an inverse relationship with home range size. Neither net primary productivity nor phylogeny was good predictors for home range variation at geographical scale. This study highlights the scale dependence of the explicative capability of a set of environmental and intrinsic variables on home range patterns.展开更多
基金supported by the National Basic Research Program of China(2010CB950703)the National Natural Science Foundation of China(41571338)
文摘In this study, we explore the feasibility of optimizing ecosystem photosynthetic and respiratory parameters from the seasonal variation of the net carbon flux. An optimization scheme is proposed to estimate two key parameters （V2max and Q10） by exploiting the seasonal variation in the net ecosystem carbon flux retrieved by an atmospheric inversion system. This scheme is implemented to estimate V25max and Q10 of the boreal ecosystem productivity simulator （BEPS） to improve its NEP simulation in the boreal North American region. Then, in situ NEE observations at six eddy covariance sites are used to evaluate the NEE simulations from BEPS with initial and optimized parameters. The results show that the performance of the optimized BEPS is superior to that of the BEPS with the default parameter values. These results implicate that it is possible to optimize ecosystem model parameters by different sensitivities of V25max and Q10 during growing and non-growing seasons through atmospheric inversion or data assimilation techniques.
文摘Animal habitat-use patterns cannot be isolated from scale issues. Consequently, multi-scale studies provide a complete characterization of ecological patterns that can further explain the observed variation. Liolaemus constitutes the world＇s second most speciose lizard genus. In this study, we assessed the relationships between home range size and environmental variables at 3 different spatial scales. The study at a local and regional scale was focused on the habitat specialist Liolaemus multimaculatus. The lizard＇s home range was calculated using the minimum convex polygon method in populations from grassland sites of the coastal sand dunes of the Argentinean Pampas under 2 different conditions, with or without forestations of Acacia Iongifolia. On the other hand, at a geographical scale we considered the evolutionary implications of 20 species of Liolaemus. Home range size, phylogeny, ecological, environmental, and climatic data were ob- tained from the literature and remote sensing. L. multimaculatus home range varied from 12.66 to 570.00 m. Regionally, this species had smaller home ranges in forested habitats （X： 94.02 m2） com- pared with the non-forested sites （X： 219.78m2）. Habitat structure, vegetation types, and food availability would explain the space use at finer scales. When the 20 species of Liolaernus were considered, high mean air temperature and broad thermal amplitudes showed an inverse relationship with home range size. Neither net primary productivity nor phylogeny was good predictors for home range variation at geographical scale. This study highlights the scale dependence of the explicative capability of a set of environmental and intrinsic variables on home range patterns.
