Diversity of subaerial algae and cyanobacteria growing on bark and wood in the lowland tropical forests of Singapore

Abstract

Background and aims -Knowledge on diversity and distribution of algae and cyanobacteria in subaerial habitats still lags behind those of freshwater and marine environments. Notably, data on diversity of microalgae in tropical corticolous habitats are still scarce. We investigated species composition of subaerial epixylic algae and cyanobacteria from two Singaporean rainforest localities. We asked whether there are differences in species composition and alpha-diversity of samples taken in different areas and in different habitat types (bark vs. decaying bare wood). In addition, we asked whether there are differences in species turnover (beta-diversity) among different habitat types and areas. Methods -The cultivation-based approach and the microscopic analysis of populations were used. In total, 20 samples of bark and decaying wood from two forested areas were analyzed. Statistical analyses involved the non-metric multidimensional scaling (NMDS) of species data. Signifi cance of differences in algal composition between groups of samples was evaluated by the non-parametric two-way ANOSIM (Analysis of Similarities) using the crossed design with permutations in blocks. The SIMPER method was used to identify species that characteristically discriminate between habitat types and sampling areas. Key results -In total, 57 species were identifi ed. Green algae (Trebouxiophyceae, Chlorophyceae, Trentepohliales) were dominant, and Cyanobacteria were the second most frequent group. The dominants of the subaerial assemblages differed from corresponding temperate habitats and, in addition, their alpha-diversity was considerably higher. Several green algal morphospecies were characteristic for the bark localities (e.g. Dictyochloropsis spp., Pseudomarvania aerophytica, Printzina effusa and Printzina lagenifera). The alpha-diversity was similar in both habitat types, but the species turnover among samples (beta-diversity) was signifi cantly higher in the decaying wood samples. Conclusions -Tropical corticolous habitats probably harbour higher diversity than corresponding temperate habitats. High beta-diversity of decaying wood illustrates general importance of this substrate for biodiversity of subaerial algae in the tropics.

Corticolous cyanobacteria from tropical forest remnants in northwestern São Paulo State, Brazil

“…Neustupa & Škaloud (2008) studied cyanobacterial and corticolous algal communities in tropical mountain habitats in Indonesia and found eight filamentous cyanobacteria species. More recently, Neustupa & Škaloud (2010) found 12 cyanobacteria species on tree bark in tropical forests in Singapore, mainly filamentous organisms (as was observed in the present study).…”

Primary biological aerosol particles in the atmosphere: a review

“…As such, particle size is by far the most important characteristic for choosing a sampling procedure for both PBAP and all other classes of airborne particles (Nicholson, 1995). Losses of particles within inlets, inlet lines and instruments can cause huge biases in both quantitative and qualitative understanding, and therefore sampling procedures must be designed properly (Zimmermann et al, 1987).…”

“…These algae are termed terrestrial, aeroterrestrial, aerophytic or subaerial, are able to reside on almost all substrates, natural or artificial and can become airborne, constituting the aero-(phyto) plankton. Chlorophycean and xanthophycean species are common worldwide (Printz, 1921;Laundon, 1985;Dubovik, 2002;Reisser, 2002;Sharma et al, 2007;Neustupa and Skaloud, 2010) and exist free living as well as lichenised (Bubrick et al, 1984). Due to the size of the algae and their spores, many smaller than 10 mm in diameter (Printz, 1921;Dubovik, 2002;Burchardt and Dankowska, 2003;Neustupa and Skaloud, 2010), they can be easily dispersed in the atmosphere.…”

“…Chlorophycean and xanthophycean species are common worldwide (Printz, 1921;Laundon, 1985;Dubovik, 2002;Reisser, 2002;Sharma et al, 2007;Neustupa and Skaloud, 2010) and exist free living as well as lichenised (Bubrick et al, 1984). Due to the size of the algae and their spores, many smaller than 10 mm in diameter (Printz, 1921;Dubovik, 2002;Burchardt and Dankowska, 2003;Neustupa and Skaloud, 2010), they can be easily dispersed in the atmosphere. In a recent review article, the mechanisms involved in the aerosolisation of algae were presented, and Sharma et al (2007) stated that 'airborne algae are the least-studied organisms in both aerobiological and phycological studies'.…”

The distribution and three newly reported species of aerial algae at Mt. Gwanggyo, Korea

“…In order to adapt to land environments, aerial algae display simplified shapes, such as globular, oval and filaments (Hoffmann 1989). Consequently, understanding the minute differences in form and alterations of shape is required to identify aerial algae based on morphology (Neustupa and Skaloud 2010).…”