Herbaceous plants of the Amazon floodplain near Manaus: Species diversity and adaptations to the flood pulse
Year: 1993
Type: article
Abstract: In the floodplain of the Amazon river near Manaus, 388 herbaceous plant species, excepting epiphytes, were collected belonging to 64 families and 182 genera. 330 species are considered terrestrial, 34 aquatic, the others have an intermediate status. Most of the species occur in relatively small numbers. Only 17 species formed large monospecific stands. The largest number of species (273) was found during the dry phase in disturbed areas on the levees, as for instance in abandoned fields, because of a reduced impact of the flood and high light intensity. Low numbers were recorded during low water period from the floor of floodplain forest (25) because of insufficient light conditions and from low lying lake beds (26), which were dominated by a few highly adapted species. The following attributes were found to favour the occurrence of herbaceous plants in the Amazon floodplain: resistance of seeds and spores to flooding and dessication; short reproductive cycles; high reproduction rates; high primary production; tolerance of adult plants to flooding and drought; adaptations to waterlevel fluctuations (for example a floating way of life). Short life cycles and high reproduction rates allow the quick colonization of disturbed habitats and the substitution of population losses (r-strategy). This strategy is supported by the elevated nutrient status of the Amazon river floodplain in comparison with the floodplain of the Negro River, where herbaceous plants are scarce. The number of ruderal species and weeds including a rising number of neophytes is large. The great species diversity is related to great habitat diversity, fertility of sediments and water, predictability of the floodpulse and the reduction of interspecifìc competition due to the annual set back of the populations by the flooding and drought. The observations are in concordance with the predictions of the floodpulse concept.
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Life on land
Open Access status: green
OpenAlex ID: W2977132641