Plant Ecology and Evolution 149(2): 144-156, doi: 10.5091/plecevo.2016.1206
Substrate specificity and fine-scale distribution of epiphytic diatoms in a shallow tarn in the Brenta Dolomites (south-eastern Alps)
Markéta Letáková, Marco Cantonati, Petr Hašler, Angeli Nicola, Aloisie Poulíčkovᇇ Univerzity Palackého, Olomouc, Czechoslovakia
© Botanic Garden Meise and Royal Botanical Society of Belgium. all rights reserved Citation:
Letáková M, Cantonati M, Hašler P, Nicola A, Poulíčková A (2016) Substrate specificity and fine-scale distribution of epiphytic diatoms in a shallow tarn in the Brenta Dolomites (south-eastern Alps). Plant Ecology and Evolution 149(2): 144-156. https://doi.org/10.5091/plecevo.2016.1206 |  |
Abstract
Background and aims – The host-specificity of epiphytic diatom species has long been debated. Scuba divers sampled epiphytic diatoms in the shallow Alpine Lake Valagola (average depth c. 2 m) along seven transects (length: 30–144 m) in West-East direction. The bottom of the tarn was covered by macrophytes dominated by Chara aspera and Potamogeton gramineus. Factors affecting epiphytic-diatom spatial distribution at a fine scale were tested.
Methods – Dataset was tested using Redundancy Analysis (CANOCO package) and one-way ANOVA (NCSS package).
Key results – The analysis separated sampling sites into two groups: the tarn shore dominated by Potamogeton gramineus, and the central area dominated by Chara aspera. Diatom species richness, diversity, and composition differed significantly between the two main host plants. Potamogeton gramineus assemblages were characterized by higher species richness and diversity, and by the large-celled, adnate diatom species Epithemia adnata, Rhopalodia gibba, Eunotia arcus and E. arcubus. Chara aspera was preferred by the small-celled, motile diatom species Brachysira neoexilis and Encyonopsis cesatii.
Conclusions – The spatial distribution of epiphytic diatoms in the shallow, oligo-mesotrophic Lake Valagola is influenced by host plant composition and distribution. Epiphyton size structure suggests that Chara represents a less appropriate substrate for long diatoms.
Methods – Dataset was tested using Redundancy Analysis (CANOCO package) and one-way ANOVA (NCSS package).
Key results – The analysis separated sampling sites into two groups: the tarn shore dominated by Potamogeton gramineus, and the central area dominated by Chara aspera. Diatom species richness, diversity, and composition differed significantly between the two main host plants. Potamogeton gramineus assemblages were characterized by higher species richness and diversity, and by the large-celled, adnate diatom species Epithemia adnata, Rhopalodia gibba, Eunotia arcus and E. arcubus. Chara aspera was preferred by the small-celled, motile diatom species Brachysira neoexilis and Encyonopsis cesatii.
Conclusions – The spatial distribution of epiphytic diatoms in the shallow, oligo-mesotrophic Lake Valagola is influenced by host plant composition and distribution. Epiphyton size structure suggests that Chara represents a less appropriate substrate for long diatoms.
Keywords
CHARA ASPERA; DIATOMS; EPIPHYTON; EPIPHYTON SIZE STRUCTURE; HOST SPECIFICITY; MOUNTAIN LAKE; POTAMOGETON GRAMINEUS