The colonization success of an exotic Poaceae is related to native macrophyte richness, wind disturbance and riparian vegetation

• Published in: Aquatic sciences Vol. 74; no. 4; pp. 809 - 815
• Main Authors: Thomaz, Sidinei Magela, Silveira, Márcio José, Michelan, Thaisa Sala
• Format: Journal Article
• Language: English
• Published: Basel SP Birkhäuser Verlag Basel 01-10-2012; Springer; Springer Nature B.V
• Subjects: Abiotic factors; Animal and plant ecology; Animal, plant and microbial ecology; Aquatic ecosystems; Aquatic plants; Biological and medical sciences; Biomedical and Life Sciences; Colonization; Ecology; Freshwater & Marine Ecology; Fundamental and applied biological sciences. Psychology; General aspects; Indigenous species; Introduced species; Life Sciences; Marine & Freshwater Sciences; Native species; Nonnative species; Oceanography; Poaceae; Research Article; Reservoirs; Riparian vegetation; Species diversity; Synecology; Terrestrial ecosystems; Urochloa; Wind; Ecological filters; Reservoir; Biotic acceptance; Invasion; Wind; Monocotyledones; Riparian vegetation; Urochloa subquadripara; Ecology; Perturbation; Aquatic environment; Filter; Gramineae; Angiospermae; Spermatophyta; Aquatic plant; Colonization; Native species
• ISSN: 1015-1621; 1420-9055
• DOI: 10.1007/s00027-012-0264-5

Biotic and abiotic factors are filters that prevent invasions in aquatic and terrestrial ecosystems. In this investigation we tested the hypothesis that the success of a non-native Poaceae (
Urochloa subquadripara
) is positively correlated with the richness of native macrophytes and negatively correlated with wind disturbance (fetch) and presence of riparian vegetation on coarse spatial scales. Our samplings were carried out in a tropical reservoir (Rosana Reservoir, Brazil). We first compared competing models using the Akaike criterion to find the main combinations of explanatory variables (native macrophyte richness, fetch, and presence of riparian vegetation) associated with the success of
U. subquadripara
. Then, we applied multiple regressions to assess the coefficient of determination of the best models selected according to the Akaike criterion. The probability of occurrence of
U. subquadripara
increased significantly with increases in the number of native macrophyte species, but decreased with fetch and the presence of riparian vegetation. Stand width and maximum depth of occurrence (indicators of the success of this Poaceae) were also positively related with native richness and negatively with fetch and riparian vegetation. Our results supported our expectation that wave disturbance is an important variable explaining
U. subquadripara
success. Because the less exposed sites are also more favorable for colonization by natives, positive relationships between the success of non-native species and native diversity emerge at the coarse scale. Taken together, our results support the theory of “biotic acceptance”; that is, favorable sites are more prone to colonization by both native and non-native species.