ABSTRACT
The objective of this study was to determine the spectral characteristic of nectar-producing flowers visited by nectarivorous birds in urban areas. This study was carried out in the central area of the city of Taubaté, in the northeast of the State of São Paulo. The sample areas included green areas, such as squares and parks, and the vegetation of streets and avenues. Twelve plant species were recorded with flowers visited by five nectar-feeding birds. The most visited flower species were those that reflected in long wavelengths (>600 nm). The study discussed the birds' detection capability due to the tetrachromatic vision of nectar-feeding birds and the conspicuity of flowers in urban environments. Finally, the study assessed the scarcity of plants attractive to nectar-feeding birds and the need for a management strategy to favour these species and biodiversity in urban areas.
Análise espectral de flores utilizada por aves nectarívoras em áreas urbanas. O objetivo deste trabalho foi estabelecer a característica espectral das flores produtoras de néctar visitadas por nectarívoros em áreas urbanas. Este estudo foi desenvolvido na região central do município de Taubaté, no nordeste do Estado de São Paulo. As áreas amostradas incluíram espaços verdes, tais como praças e parques e a vegetação das ruas e avenidas. Foram registradas 12 espécies de plantas utilizadas por cinco espécies de aves nectarívoras. As espécies de flores mais visitadas foram aquelas que refletiram em comprimento de onda longos (>600 nm). Foi discutida a capacidade de detecção das aves em função de visão tetracromática das aves nectarívoras e da conspicuidade das flores em ambientes urbanos. Finalmente, foi abordado o problema da escassez de plantas atrativas para aves nectarívoras nas áreas verdes urbanas e a necessidade de se aumentar a quantidade dessas espécies de plantas para incrementar a biodiversidade em regiões urbanas.
ABSTRACT
Object To study the variation of total flavonoids in Erigeron breviscapus (Vant.) Hand.-Mazz. with the development periods, the months, the affection of the environment and genetical factors on the total flavonoids. Methods The total flavonoids in organs of E. breviscapus during the different deve-lopment periods and the months were determined. The total flavonoids of E. breviscapus in the sunny and shady habitats and the total flavonoids of E. breviscapus with different colors were compared. Results The total flavonoids of E. breviscapus mainly existed in the ground part. The total flavonoids of E. breviscapus are the highest in its flourishing period, and the lowest in its withering period. The variety of the total flavonoids in every organs of E. breviscapus in flourishing period from April to June was not significant. Illumination intensity had little affection to the total flavonoids of E. breviscapus. The colors of E. breviscapus flowers could not be the selected markers for the total flavonoids. The genetic factor played an important role in deciding the difference of the total flavonoids among the individuals. Conclusion It will be optimistic to improve the total flavonoids in E. breviscapus by genetic breeding.