Ann. Limnol. - Int. J. Lim.
Volume 50, Number 2, 2014
|Page(s)||163 - 171|
|Published online||04 April 2014|
Morphometric and biotic variables as potential predictors of Ludwigia sedoides (Humb. & Bonpl.) Hara in a large Amazonian reservoir
1 Programa de Pós-Graduação em Ecologia de Ecótonos, Universidade Federal do Tocantins, Porto Nacional, Tocantins, Brazil
2 Fundação Universidade do Tocantins (Unitins), Palmas, Tocantins, Brazil
3 Núcleo de Estudos Ambientais (Neamb), Universidade Federal do Tocantins, Porto Nacional, Tocantins, Brazil
* Corresponding author: firstname.lastname@example.org
Accepted: 3 March 2014
Reservoirs cause hydrological changes (i.e., water level stabilization) that favor the colonization of aquatic macrophytes. Knowing the ecological factors that determine the occurrence of these plants is critical for water management (e.g., plant control) and biodiversity conservation. In this sense, the present study investigated colonization patterns of Ludwigia sedoides in Lajeado reservoir (Tocantins River, Amazon Basin), in order to identify variables that influence colonization at habitat scale. We investigated the relationship between colonization (coverage area and occurrence) and morphometric (fetch, slope, depth and distance from shoreline) and biotic variables (local diversity of macrophytes and co-occurrence patterns). Stepwise regression selected fetch, depth and slope as the best variables to explain the variation in L. sedoides coverage, which together explained 46% of data variability. Fetch and slope were negatively correlated with coverage, whereas depth showed a positive correlation. No biotic variable was included in the model (P>0.05). However, the investigation of the geometric shape of bivariate correlations (null models) showed positive relationships with local species richness and richness of life forms (i.e., submerged, emergent, floating and epiphytic). In addition, an analysis of species co-occurrence (C-score) revealed that L. sedoides is negatively associated with some macrophyte species. We believe, however, that these results may be associated with species preferences for particular environmental conditions. In conclusion, the present study indicated that morphometric variables are potential predictors of the colonization of L. sedoides in Lajeado reservoir. Sheltered sites with low slope and moderate depths represent favorable environment for colonization and growth.
Key words: co-occurrence / depth / fetch / slope / spatial distribution
© EDP Sciences, 2014
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.