Effects of crevice size on the establishment of macroalgae in subtropical streams

Brazilian Journal of Biology

Af Tonetto¹  Ck Peres¹  Ma Khnayfes¹  Ccz Branco¹ 

关键词: habitat structure;    surface shape;    artificial substrate;    refugia;    stream macroalgae;    estrutura do hábitat;    forma da superfície;    substrato artificial;    refúgios;    macroalgas de riachos;   

DOI  :  10.1590/1519-6984.03813

来源: SciELO

【 摘 要 】

Considering that in previous studies, the surface roughness (micrometric dimension) showed a weak effect on the colonization of stream macroalgae, we investigated the effects of different crevice sizes (milimetric dimension, a scale slightly higher than previous investigations) on the macroalgal abundance in three streams exposed to full sunlight in southern Brazil. We used smooth sterile glass plates with different shapes: P – plane surface without crevices; S – sinuous surface (depth of crevices with 0.159 mm ± 0.03); N – non-unifom surface (0.498 mm ± 0.09); C – surfaces with convex structures (1.190 mm ± 0.12); and three additional surface types with different patterns of heterogeneity with combinations of glass pieces: P + S (H1); P + S + N (H2) and P + S + N + C (H3). The plates were placed into the streams and after 105 days the percent cover of macroalgal community was measured. No significant differences among treatments were recorded. However, we observed a trend of macroalgae occurs within the crevices in all treatments and this suggests that, for stream macroalgae, the crevice sizes used in this study was still not enough to provide an expressive algal growth, even in the treatment with bigger crevices.

【 授权许可】

CC BY   
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