Insect Communities

New GAUK grant for our group

Recently our group, with Yannick as the principal investigator, has successfully applied for a student grant by the Grant Agency of the Charles University (GAUK).  The project is entitled “The importance of seasonality in shaping plant-pollinator networks in tropical montane forest” and will be focused on collecting data from more seasons in the montane forests around Mann’s Spring on Mt. Cameroon. We are very grateful to the Charles University for this opportunity to gain a better understanding of the influence of seasonality on pollination networks.

Our field camp in the Mann’s Spring area. © Francis Luma Ewome

Exploring floristic diversity in the Afrotropics

This week a new publication on the floristic diversity in the afrotropics, co-autored by Yannick, has been published in BMC Biology using the RAINBIO database. In this paper, spatial variation in floristic diversity and data collection is shown. Furthermore, it also shows the difficulties arising with quantifying diversity patterns using data gathered from different sources, with herbaria specimens being the main data source. More botanical exploration is needed to fill important gaps in our knowledge regarding afrotropical plant communities. However, the data presented already gives a good backbone for more sustainable management and improved conservation practices of Africa’s rich and unique flora. The paper has already received positive commentary in BMC Biology by one of the editorial board members (Magurran 2017) and has been the focus of a blogpost on the BMC Biology webpage.

The Afrotromontane forest canopy at Mann Spring, Mt. Cameroon. © Š. Janeček

Full citation: Sosef, M.S.M., Dauby, G., Blach-Overgaard, A., van der Burgt, X., Catarino, L., Damen, T., Deblauwe, V., Dessein, S., Dransfield, J., Droissart, V., Duarte, M.C., Engledow, H., Fadeur, G., Figueira, R., Gereau, R.E., Hardy, O.J., Harris, D.J., de Heij, J., Janssens, S., Klomberg, Y., Ley, A.C., Mackinder, B.A., Meerts, P., van de Poel, J.L., Sonké, B., Stévart, T., Stoffelen, P., Svenning, J-C., Sepulchre, P., Zaiss, R., Wieringa, J.J.,  and Couvreur, T.L.P. (2017) Exploring the floristic diversity of tropical Africa. BMC Biology 15:15

Back from another successful expedition

Rob, Jan, Yannick, Pavel and our close collaborator Štěpán Janeček have returned, mostly unscathed, from our dry season expedition on Mt. Cameroon. They continued with our research on pollination systems, as well as lepidopteran diversity in the three higher elevations of the mountain. One of our other collaborators, Szabolcs Sáfián, joined us for two weeks to help with the lepidopteran work.

Štěpán setting a camera in the canopy of Syzygium staudtii.

This expedition has provided enormous amounts of data, especially within our pollination research. Over 250 plants were filmed for ±24 hours in order to record their visitors. In the coming months both Jan and Yannick will try to process these recordings (from both last expeditions), but initial checks have already sparked their enthusiasm due to visitation from a wide range of species, e.g. bats, sunbirds, sphingids and rodents.

Just within a month another part of our group (Vincent, Sylvain and Pavel) will already return to finally finish the lepidopteran data collection.

New study on competition in pollination systems

For already a few years, our group collaborates in research of a pollination system of Hypoestes aristata plant in the Cameroonian Bamenda Highlands. We have already revealed the carpenter bee Xylocopa caffra to be its most frequent and efficient pollinator among the wide range of various flower-visiting species. Besides many different insect groups, the flowers are also visited by the northern double-collared sunbird (Cinnyris reichenowi) which does not contribute to the plant’s reproductive success. The sunbird significantly decreases the amount of nectar available for the real pollinators while depleting the nectar sources, and moreover it chases the carpenter bee of the flowering patches while defending the nectar sources. In the new publication, currently published in the prestigious Oecologia journal, we have compared daily energetic requirements of the mentioned frequent visitor species in relation to diurnal changes in the nectar quality and quantity. Our simplistic energetic model showed the smaller carpenter bee as competitively superior to the larger sunbird due to its smaller energy requirements. The larger sunbird seems to reduce this asymmetry in the exploitative competition by its use of the resources when the smaller competitor is inactive, its higher speed of the nectar consumption and the aggressive behaviour. Our study is one of the very few publications reporting the energetic point of view of competition among phylogenetically unrelated nectarivors.

Female (left) and male of Xylocopa caffra on flowers of Hypoestes aristata (© R. Tropek)

Citation: Padyšáková E., Okrouhlík J., Brown M., Bartoš M., Janeček Š. (in press) Asymmetric competition for nectar between a large nectar thief and a small pollinator: an energetic point of view. Oecologia.

New invasive crayfish for Czechia

During our long-term research of freshwater communities of lignite spoil heaps in Nortwestern Bohemia, we have also found several adult females of marbled crayfish (Procambarus fallax f. virginalis) in an artificial pool at the Radovesická spoil heap. Simultaneously, our colleagues led by Jiří Patoka have found another population inhabiting a public park in downtown Prague. Just recently, both our finds have been published by the Biologia journal. The marbled crayfish is an invasive species from Northern America with a strong impact on local communities of native crayfish, as well as the general freshwater biota. Unfortunately, it is a very common aquarium pet, the hobbyists are often responsible for its introduction to new localities. We hope that our new records will help to increase awareness amongst aquarists regarding the danger of spreading of unwanted non-native species. Simultaneously, we will try to initiate its eradication from both localities to avoid spreading to the common landscape.

Locality and picture of the marbled crayfish found in the Radovesická spoil heap. © V. Kolář (and Biologia).

Full citation: Patoka J., Buřič M., Kolář V., Bláha M., Petrtýl M., Franta P., Tropek R., Kalous L., Petrusek A., Kouba A. (2016) Predictions of marbled crayfish establishment in conurbations fulfilled: evidences from the Czech Republic. Biologia 71: 1380-1385.

New publication on efficient habitat restoration for newts

Northern crested newt prefers non-reclaimed post-mining pools. © V. Kolář

As a by-product of our intensive research of freshwater invertebrates at lignite spoil heaps, we have also sampled enough newts to make an analysis of their needs during restoration possible. Just recently, results of this side project have been published in Ecological Engineering. As expected, both newt species colonising secondary habitats at the northern Bohemian spoil heaps avoid reclaimed artificial pools. Similarly to our numerous studies of terrestrial biodiversity, spontaneous processes, rather than costly technical reclamation, seem to be more efficient in habitat restoration. On the other hand, our previous studies of dragonflies have revealed completely different patterns. At the moment, Vojta Kolář and Filip are analysing the large dataset of water insects sampled during the past two years. We are looking forward to the results.

Full citation: Kolář V., Tichanek F., Tropek R. (2017) Effect of different restoration approaches on two species of newts (Amphibia: Caudata) in Central European lignite spoil heaps. Ecological Engineering 99, 310–315.

New publication on Afrotropical plant distribution

In the past year Yannick has contributed to the creation of RAINBIO during his work for the Naturalis Biodiversity Center in the Netherlands. The RAINBIO is a comprehensive mega-database of georeferenced records for vascular plants in continental tropical Africa. Recently a data paper was published making the database accessible to everyone. As one can see below our research area Mt. Cameroon is well represented in the database, therefore it will be useful also for our work. In the near future the creators of this database (including Yannick) will publish another paper analysing the floristic diversity of tropical Africa using the RAINBIO data.

Density of records (left) and coverage (right) of the RAINBIO database (Dauby et al. 2016). © Phytokeys.

Full citation: Dauby et al. (including Y. Klomberg) (2016) RAINBIO: a mega-database of tropical African vascular plants distributions. Phytokeys 74: 1-18.

(Partly) back from Africa

Michael and Yannick setting a camera on Impatiens mannii’s flowers.

The majority of us are back from Africa. Yannick, Jan, Vincent and Michael Bartoš have returned, mostly unscathed, from their expedition to Mt. Cameroon on Friday. They continued with our research on pollination systems, as well as lepidopteran diversity in the higher elevations of Mt. Cameroon. Simultaneously, Robert has come back from southern Africa yesterday, where he has been sampling moths along a gradient of environmental productivity. In a bit more than a week, Eliška, Sylvain and Petra Janečková will also return from the Bamenda Highlands in Cameroon. They are still collecting data on both pollination systems and moths. Now, we have approximately a month for recovering and preparing of the next Cameroonian expedition in late January 2017.