Twenty years of lichen cover change in a tropical habitat (Costa Rica) and its relation with air pollution
Rev. biol. trop
;
50(1): 309-319, Mar. 2002.
Artigo
em Inglês
| LILACS
| ID: lil-333021
RESUMO
We report lichen cover change over a 20 years period for the Costa Rican capitol city. Foliaceous lichen cover was measured with a 10 x 10 cm template positioned 1.5 m above ground on the south, east, north and west sides of ten phorophytic trees per station (11 stations) from 1976 through 1997. Results were compared with previous measurements along an urban transect (at three heights above ground) and in a rural station. Lichen cover was correlated with traffic density and varied between stations and years. Mean lichen cover was 23 in 1976, 12 in 1986, 9 in 1990 and 22 in 1997. Most stations suffered a large cover reduction after 1976 but improved after 1990, possibly reflecting improved traffic regulations and elimination of lead (Pb) from gasoline. Cover values by cardinal orientation were west 17, east 14, north 13 and south 12. Sidewalks of streets with more traffic had lower cover values. In the rural station, cover was lower than expected (possibly because of climate), and was not correlated with height above ground or cardinal orientation, in contrast with temperate regions. In polluted cities human activity should concentrate above the first floor of buildings (particularly in hospitals or schools) because pollution was found to concentrate in the first 2 m above ground.
Buscar no Google
Índice:
LILACS (Américas)
Assunto principal:
Poluentes Atmosféricos
/
Poluição do Ar
/
Líquens
Limite:
Humanos
País/Região como assunto:
América Central
/
Costa Rica
Idioma:
Inglês
Revista:
Rev. biol. trop
Assunto da revista:
Biologia
/
Medicina Tropical
Ano de publicação:
2002
Tipo de documento:
Artigo
País de afiliação:
Costa Rica
Instituição/País de afiliação:
Universidad de Costa Rica/CR
Similares
MEDLINE
...
LILACS
LIS