Associations between a highly invasive species and native macrophytes differ across spatial scales |
| |
Authors: | Sidinei Magela Thomaz Thaisa Sala Michelan |
| |
Institution: | 1.DBI/Nupélia/PEA,Universidade Estadual de Maringá,Maringá,Brazil;2.ICB, DE,Universidade Federal de Goiás,Goiania,Brazil |
| |
Abstract: | The association between invasive and native species varies across spatial scales and is affected by phylogenetic relatedness,
but these issues have rarely been addressed in aquatic ecosystems. In this study, we used a non-native, highly invasive species
of Poaceae (tropical signalgrass) to test the hypotheses that (i) tropical signalgrass success correlates negatively with
success of most native species of macrophytes at fine spatial scales, but its success correlates positively or at random with
natives at coarse spatial scales, and that (ii) tropical signalgrass is less associated with native species belonging to the
family Poaceae than with species belonging to other families (Darwin’s naturalization hypothesis). We used a dataset obtained
at fine (0.25 m2) and coarse (ca. 1,000 m2) scales. The presence/absence of all species was recorded at both scales, and their biomass was also measured at the fine
scale. We tested the association between tropical signalgrass biomass and individual native species with logistic regressions
at the fine scale, and using the T-score index between tropical signalgrass and each native species at both scales. The likelihood
of the occurrence of six species (submersed and free-floating) was negatively affected by tropical signalgrass biomass at
the fine scale. T-scores showed that three species were less associated with tropical signalgrass than expected by chance,
but 22 species co-occurred more than expected by chance at the coarse scale. Associations between species of Poaceae and tropical
signalgrass were null at the fine scale, but were positive or null at the coarse scale. In addition to showing that spatial
scale affects the patterns of association among the non-native and individual native species, our results indicate that phylogeny
did not explain associations between the invasive and native macrophytes, at both scales. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|