Megjelent 2 új cikkünk 

Megjelent B-Béres Viktória elsőszerzőségével legújabb cikkünk az Ecological Indicators szakfolyóiratban (B-Béres, V., Lukács, Á., Török, P., Kókai, Zs., Novák, Z., T-Krasznai, E., Tóthmérész, B. I. Bácsi (2016): Combined eco-morphological functional groups are reliable indicators of colonisation processes of benthic diatom assemblages in a lowland stream. Ecological Indicators 64: 31-38.). A cikkben elsőként teszünk javaslatot kombinált ökológiai csoportok alkalmazására a kovaalga közösségek fajdinamikai folyamatainak értelmezésében. A cikk elkérhető a szerzőktől. A cikk összefoglalója az alábbiakban olvasható.

Abstract:

Classifying benthic diatom taxa based on ecological and morphological features became increasingly important in recent years due to the demand of understanding the dynamics and functioning of diatom assemblages. The great potential in using these functional classifications in diatom ecology involves further refinement of current classification. In our experimental study, colonisation processes of diatom assemblages were studied in a typical small lowland stream, using both diatom guilds and cell size categories. We also tested newly proposed combined eco-morphological functional groups (ecological guilds combined with cell size categories) in the study of the colonisation process in benthic diatom assemblages. We hypothesised that (i) there is a decrease in the proportion of low profile guild, while an increase in that of high profile and motile guilds in time with the decreasing rate of physical disturbance; (ii) the presence of small size categories will be pronounced at the beginning of the colonisation processes, while proportion of larger size categories will be higher in the latter phases of colonisation; and (iii) the relationship between taxa and environmental factors are better reflected by the use of combined eco-morphological functional groups than by the sole analyses of rough guilds or cell size categories. The first hypothesis was not confirmed, and our second hypothesis was only partially confirmed by the results. We found that the relationship between environmental factors and guilds, as well as cell size categories was not appropriate to reveal the relationship between abiotic factors and taxa composition. In contrast we found that compositional changes in colonisation were appropriately reflected by the newly defined combined eco-morphological functional groups. In the combined eco-morphological functional groups, such kind of taxonomical and ecological features can be prevailed which are hidden in guilds or cell size categories separately. Thus these combined eco-morphological functional groups could help to come one step closer to develop a widely used ecological classification in diatom researches.

Keywords: Eco-morphological functional groups; Diatom guilds; Cell size categories; Colonisation; Lowland stream

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A másik cikk Török Péter elsőszerzőségével jelent meg a szakma egyik rangos nemzetközi lapjánál a Functional Ecology-nál (Török P., T-Krasznai E., B-Béres V., Bácsi I., Borics G., Tóthmérész B.  (2016): Functional diversity supports the biomass-diversity humped-back relationship in phytoplankton assemblages. Functional Ecology. DOI: 10.1111/1365-2435.12631). A cikk összefoglalója az alábbiakban olvasható. A cikk elkérhető a szerzőktől.


Abstract:

1. Modelling the relationship between biomass and diversity in phytoplankton assemblages provides new insights into the mechanisms responsible for the coexistence of species, even in terrestrial ecosystems.

2. We tested the biomass-diversity relationship in lake phytoplankton along a wide biomass gradient using functional species groups. We hypothesized that changes in the taxonomic diversity of the phytoplankton along a biomass gradient are associated with altered functional diversity.

3. For the analyses, in total 768 samples were collected from 30 oxbows, reservoirs and lakes in the Hungarian Lowland Region and analysed between 1992 and 2002.

4. We found that the diversity and also the number of functional species groups showed a humped-back curve similar to the species richness. The changes in functional group composition act as a good proxy for phytoplankton species responses. We found that the peak of the number of strategy groups and their Shannon diversity was at a much lower biomass than that of species richness.

5. We revealed the fine-scale effects of increasing the dominance of respective species or species groups with increasing biomass. This increase was well reflected by the changes in the functional characteristics: first, the species evenness; then, the Shannon diversity; and finally, the species richness started to decrease with increasing biomass.

6. Cyanoprokaryota were positively correlated with increasing biomass and negatively with the increase in species richness; thus, the high increase both in their abundance and biomass can be responsible for the abruptly decreasing part of the humped-back curve.

7. We detected a humped-back curve between biomass and diversity, where the peak compared to terrestrial plant communities tended to be towards high biomass scores, that is, greater than 60% instead of the 20 to 60% of the biomass range typical for terrestrial plant communities. Marked differences in the structural and dynamic features of phytoplankton assemblages and terrestrial plant communities are likely responsible for this difference.

Keywords: algae, ecological strategy, functional redundancy, functional strategies, humpback model, species richness, unimodal curve