This paper describes and analyzes floristic, structural and conservation features of the shrubland occupied by Chersophilus duponti in the northwest corner of its world distribution range. This study relates the cover...This paper describes and analyzes floristic, structural and conservation features of the shrubland occupied by Chersophilus duponti in the northwest corner of its world distribution range. This study relates the coverage, floristic composition with estimated lark density in the area. We identified four types of shrublands, three of them varied significantly in floristic composition for the habitats of this species in contrast with those of their world distribution: Cistus ladanifer scrubs;heaths dominated by Ericaceae, and scrubs dominated by the genera Lavandula, Thymus and Cytisus. The fourth type, dominated by aromatic chamaephytes and grass, fits descriptions of the bird’s typical habitat. The areas sampled are subject to different categories of threats, the most significant being the natural succession process due to the cessation of grazing, reforestation measures and the use of flat areas for farmlands or other uses. The density of larks in this area was directly related to coverage-composition of plant community.展开更多
This study was designed to examine relationships between climate and vegetation of the Pacific rim of North America, from the Mediterranean deserts of California to Alaska’s boreal taiga. Relations were inferred from...This study was designed to examine relationships between climate and vegetation of the Pacific rim of North America, from the Mediterranean deserts of California to Alaska’s boreal taiga. Relations were inferred from temperature and rainfall data recorded at 457 weather stations and by sampling the vegetation around these stations. Climate data were used to construct climatograms, calculate forty one variables and detect main latitudinal and longitudinal gradients. In order to identify the best functions able to relate our variables, polynomial and non-polynomial regressions were performed. The k-means algorithm was the clustering method used to validate the variables that could best support our bioclimatic classification. The variable that best fitted our classification was finally used to prepare a discriminatory key for bioclimates. Across this extensive area three macrobioclimates were identified, Mediterranean, Temperate and Bo- real, within which we were able to distinguish nine bioclimates. Finally, we relate the different types of potential natural vegetation to each of these bioclimates and describe their floristic composition and physiognomy.展开更多
文摘This paper describes and analyzes floristic, structural and conservation features of the shrubland occupied by Chersophilus duponti in the northwest corner of its world distribution range. This study relates the coverage, floristic composition with estimated lark density in the area. We identified four types of shrublands, three of them varied significantly in floristic composition for the habitats of this species in contrast with those of their world distribution: Cistus ladanifer scrubs;heaths dominated by Ericaceae, and scrubs dominated by the genera Lavandula, Thymus and Cytisus. The fourth type, dominated by aromatic chamaephytes and grass, fits descriptions of the bird’s typical habitat. The areas sampled are subject to different categories of threats, the most significant being the natural succession process due to the cessation of grazing, reforestation measures and the use of flat areas for farmlands or other uses. The density of larks in this area was directly related to coverage-composition of plant community.
基金supported by grants from the Franklin Institute of North American Studies(University of Al-calá).
文摘This study was designed to examine relationships between climate and vegetation of the Pacific rim of North America, from the Mediterranean deserts of California to Alaska’s boreal taiga. Relations were inferred from temperature and rainfall data recorded at 457 weather stations and by sampling the vegetation around these stations. Climate data were used to construct climatograms, calculate forty one variables and detect main latitudinal and longitudinal gradients. In order to identify the best functions able to relate our variables, polynomial and non-polynomial regressions were performed. The k-means algorithm was the clustering method used to validate the variables that could best support our bioclimatic classification. The variable that best fitted our classification was finally used to prepare a discriminatory key for bioclimates. Across this extensive area three macrobioclimates were identified, Mediterranean, Temperate and Bo- real, within which we were able to distinguish nine bioclimates. Finally, we relate the different types of potential natural vegetation to each of these bioclimates and describe their floristic composition and physiognomy.
