Die Baumkronenspinnen (Araneae) des Leipziger Auwaldes

The canopy spiders of the floodplain forest in Leipzig have become a focus of ecological studies in recent years. In 2006 we sampled 30 tree canopies in the ‘Burgaue’ nature reserve with pyrethrum knock-down fogging, recording 502 adult spiders belonging to 48 species and 11 families. Based on these data and the results of a previous fogging study, the studied spider community was dominated by forest and forest-edge species with a preference for the shrub and canopy strata as well as by spiders of the web spider feeding guild. The community structure was typical for arboreal spider communities from northern temperate forests but very different from communities in the tropics. Species richness and evenness were similar to the old growth near-primary Białowieża Forest in Poland. The checklist of 96 canopy spider species of the floodplain forest of Leipzig includes 54 additions to the spider fauna of Leipzig and vicinity by recent canopy studies and eight first canopy records for Leipzig from our field work. The theridiid Dipoena torva (Thorell, 1875) was recorded for the first time in Saxony. The floodplain forest of Leipzig sustains a large and species-rich arboreal spider community and is thus a valuable habitat for a large proportion of endangered species (12%).Die Spinnen der Baumkronen des Leipziger Auwaldes wurden in den vergangenen Jahren ein Schwerpunkt ökologischer Forschung. Im Jahr 2006 untersuchten wir 30 Baumkronen im Naturschutzgebiet „Burgaue“ mithilfe der Insektizid-Baumkronenbenebelung und erhielten dabei 502 adulte Spinnen aus 48 Arten und 11 Familien. Basierend auf diesen Daten und Ergebnissen einer früheren Benebelungsstudie fanden wir, dass die untersuchte Spinnengemeinschaft von Wald- und Waldrandarten mit Präferenz für die Strauch- und Kronenschicht dominiert war. Auf Gildenniveau dominierten die Netzspinnen. Die Gemeinschaftsstruktur war typisch für eine arboreale Spinnengemeinschaft der nördlichen temperaten Wälder aber sehr verschieden von Gemeinschaften in den Tropen. Artenvielfalt und Evenness waren ähnlich dem Urwald von Białowieża in Polen. Aufgrund der Baumkronenforschungen in Leipzig beinhaltet die Baumkronen-Checkliste der 96 Spinnenarten des Leipziger Auwaldes 54 Erstnachweise für Leipzig und Umgebung. Acht Arten wurden erstmals durch unsere neuen Feldarbeiten in Leipzig nachgewiesen, die Kugelspinne Dipoena torva (Thorell, 1875) dabei erstmals in Sachsen. Der Leipziger Auwald beherbergt eine große und artenreiche arboreale Spinnengemeinschaft und ist ein wertvolles Habitat für einen großen Anteil gefährdeter Arten (12 %)

Is there an influence of the red wood ant Formica polyctena FOERSTER on species composition and structure of spider communities of oak trees?

We collected spider communities of oak trees in a Bavarian forest (Germany) by insecticidal knockdown fogging and investigated how communities changed on trees where predacious Formica polyctena ants were dominant. Spider communities of 'ant-trees' harboured significantly more spiders, mostly juveniles, and were different in familial- and species composition. In particular, Clubionidae, Salticidae, Araneidae und Linyphiidae were sampled in higher abundances from trees with ants. In contrast, lower numbers of Theridiidae (mostly Enoplognatha ovata) and Anyphaenidae were collected. Within Linyphiidae, which dominated all communities in terms of individuals and species numbers, Linyphia triangularis (only juveniles) was found in much higher numbers on oak trees with ants.Mit Hilfe von lnsektizidbenebelungen wurden die Spinnengemeinschaften von Eichen in Bayern (Deutschland) gesammelt und mit Gemeinschaften verglichen, in denen Formica polyctena-Ameisen numerisch dominierten. Von den mit Ameisen belaufenen Baumen wurden signifikant mehr Spinnen gesammelt und das Verhältnis von Adulten zu Juvenilen war zu den Juvenilen hin verschoben. Die Spinnengemeinschaften zeigten deutliche Unterschiede auf dem Niveau der Familien- und Artenzusammensetzung. Insbesondere wurden bei Anwesenheit von Ameisen mehr Clubioniden, Salticiden, Araneiden und Linyphiiden gesammelt. Dagegen wurden weniger Theridiiden (insbesondere Enoplognatha ovata) und Anyphaeniden auf den „Ameisenbäumen“ gefunden. Innerhalb der abundanz- und artenmäßig dominanten Linyphiiden wurde Linyphia triangularis in sehr viel höherer Anzahl aus den Bäumen mit Ameisen gesammelt

Beeinflusst die Anwesenheit der Waldameise Formica polyctena Foerster die Artenzusammensetzung und Struktur von Spinnengemeinschaften auf Eichen?

We collected spider communities of oak trees in a Bavarian forest (Germany) by insecticidal knockdown fogging and investigated how communities changed on trees where predacious Formica polyctena ants were dominant. Spider communities of 'ant-trees' harboured significantly more spiders, mostly juveniles, and were different in familial- and species composition. In particular, Clubionidae, Salticidae, Araneidae and Linyphiidae were sampled in higher abundances from trees with ants. In contrast, lower numbers of Theridiidae (mostly Enoplognatha ovata) and Anyphaenidae were collected. Within Linyphiidae, which dominated all communities in terms of individuals and species numbers, Linyphia triangularis (only juveniles) was found in much higher numbers on oak trees with ants

DNA barcoding data release for Coleoptera from the Gunung Halimun canopy fogging workpackage of the Indonesian Biodiversity Information System (IndoBioSys) project

We present the results of a DNA barcoding pipeline that was established as part of the German-Indonesian IndobioSys project - Indonesian Biodiversity Information System. Our data release provides the first large-scale diversity assessment of Indonesian coleoptera obtained by canopy fogging. The project combined extensive fieldwork with databasing, DNA barcode based species delineation and the release of results in collaboration with Indonesian counterparts, aimed at supporting further analyses of the data. Canopy fogging on 28 trees was undertaken at two different sites, Cikaniki and Gunung Botol, in the south-eastern area of the Gunung Halimun-Salak National Park in West Java, Indonesia. In total, 7,447 specimens of Coleoptera were processed, of which 3,836 specimens produced DNA barcode sequences that were longer than 300 bp. A total of 3,750 specimens were assigned a Barcode Index Number (BIN), including 2,013 specimens from Cikaniki and 1,737 specimens from Gunung Botol. The 747 BINs, that were obtained, represented 39 families of Coleoptera. The distribution of specimens with BINs per tree was quite heterogeneous in both sites even in terms of the abundance of specimens or diversity of BINs. The specimen distribution per taxon was heterogeneous as well. Some 416 specimens could not be identified to family level, corresponding to 72 BINs that lack a family level identification. The data have shown a large heterogeneity in terms of abundance and distribution of BINs between sites, trees and families of Coleoptera. From the total of 747 BINs that were recovered, 421 (56%) are exclusive from a single tree. Although the two study sites were in close proximity and separated by a distance of only about five kilometres, the number of shared BINs between sites is low, with 81 of the 747 BINs. With this data release, we expect to shed some light on the largely hidden diversity in the canopy of tropical forests in Indonesia and elsewhere

Arthropod distribution in a tropical rainforest: tackling a four dimensional puzzle

Quantifying the spatio-temporal distribution of arthropods in tropical rainforests represents a first step towards scrutinizing the global distribution of biodiversity on Earth. To date most studies have focused on narrow taxonomic groups or lack a design that allows partitioning of the components of diversity. Here, we consider an exceptionally large dataset (113,952 individuals representing 5,858 species), obtained from the San Lorenzo forest in Panama, where the phylogenetic breadth of arthropod taxa was surveyed using 14 protocols targeting the soil, litter, understory, lower and upper canopy habitats, replicated across seasons in 2003 and 2004. This dataset is used to explore the relative influence of horizontal, vertical and seasonal drivers of arthropod distribution in this forest. We considered arthropod abundance, observed and estimated species richness, additive decomposition of species richness, multiplicative partitioning of species diversity, variation in species composition, species turnover and guild structure as components of diversity. At the scale of our study (2km of distance, 40m in height and 400 days), the effects related to the vertical and seasonal dimensions were most important. Most adult arthropods were collected from the soil/litter or the upper canopy and species richness was highest in the canopy. We compared the distribution of arthropods and trees within our study system. Effects related to the seasonal dimension were stronger for arthropods than for trees. We conclude that: (1) models of beta diversity developed for tropical trees are unlikely to be applicable to tropical arthropods; (2) it is imperative that estimates of global biodiversity derived from mass collecting of arthropods in tropical rainforests embrace the strong vertical and seasonal partitioning observed here; and (3) given the high species turnover observed between seasons, global climate change may have severe consequences for rainforest arthropods1012CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQSolVin-Solvay SA; Smithsonian Institution; Smithsonian Tropical Research Institute; United Nations Environment Programme; Smithsonian Institution; Smithsonian National Museum of Natural History; European Science Foundation (ESF); Global Canopy Programme; Czech Science foundation GACR grant; European Social Fund (ESF); Ministry of Education, Youth & Sports - Czech Republic; French National Research Agency (ANR); Research Council of Norway; Grant Agency of the Czech Republi

The canopy spiders (Araneae) of the floodplain forest in Leipzig

Volume: 39Start Page: 25End Page: 3

Diversity of Curculionoidea in Humid Rain Forest Canopies of Borneo: A Taxonomic Blank Spot

From 1992 to 2009, 334 trees were sampled by insecticidal knockdown on Borneo, Malaysia. Here, we describe the taxonomic composition of the 9671 specimens and 1589 species Curculionoidea collected (with additional notes on Cerambycidae). We found a largely unknown fauna with an assumed proportion of over 80% of species new to science, including all 33 Apionidae and 26 Ceutorhynchinae species. Specialists could usually identify only a few specimens leaving the remaining beetles for further investigation. The samples contain numerous genera, two tribes (Egriini, Viticiini), one subfamily (Mesoptiliinae) and one family (Belidae) new to Borneo and several genera not recorded west of the Wallace line before. These data show how little is known about canopy diversity. The lack of taxonomic knowledge implies a respective lack of autecological knowledge and is alarming. Some taxa differed conspicuously between primary and disturbed forests. In contrast to common literature, our results let us conclude that current efforts to narrow down the extent of tropical diversity and its ecological importance must consider the enormous species diversity of the canopy

Are Temperate Canopy Spiders Tree-Species Specific?

Arboreal spiders in deciduous and coniferous trees were investigated on their distribution and diversity. Insecticidal knock-down was used to comprehensively sample spiders from 175 trees from 2001 to 2003 in the Białowieża forest and three remote forests in Poland. We identified 140 species from 9273 adult spiders. Spider communities were distinguished between deciduous and coniferous trees. The richest fauna was collected from Quercus where beta diversity was also highest. A tree-species-specific pattern was clearly observed for Alnus, Carpinus, Picea and Pinus trees and also for those tree species that were fogged in only four or three replicates, namely Betula and Populus. This hitherto unrecognised association was mainly due to the community composition of common species identified in a Dufrene-Legendre indicator species analysis. It was not caused by spatial or temporal autocorrelation. Explaining tree-species specificity for generalist predators like spiders is difficult and has to involve physical and ecological tree parameters like linkage with the abundance of prey species. However, neither did we find a consistent correlation of prey group abundances with spiders nor could differences in spider guild composition explain the observed pattern. Our results hint towards the importance of deterministic mechanisms structuring communities of generalist canopy spiders although the casual relationship is not yet understood

DIVERSITY OF ARBOREAL SPIDERS IN PRIMARY AND DISTURBED TROPICAL FORESTS

Volume: 33Start Page: 323End Page: 33

Diversity and functional relevance of canopy arthropods in Central Europe

Although much is known about the ecology and functional importance of canopy arthropods in temperate forests, few studies have tried to assess the overall diversity and investigate the composition and dynamics of tree-specific communities. This has impeded a deeper understanding of the functioning of forests, and of how to maintain system services. Here, we present the first comprehensive data of whole arthropod communities, collected by insecticidal knockdown (fogging) from 1159 trees in 18 study areas in Central Europe during the last 25 years. The data includes 3,253,591 arthropods from 32 taxa (order, suborder, family) collected on 24 tree species from 18 genera. Fogging collects free-living, ectophytic arthropods in approximately the same number as they occur in the trees. To our knowledge, these are the most comprehensive data available today on the taxonomic composition of arboreal fauna. Assigning all arthropods to their feeding guild provided a proxy of their functional importance. The data showed that the canopy communities were regularly structured, with a clear dominance hierarchy comprised of eight ‘major taxa’ that represented 87% of all arthropods. Despite significant differences in the proportions of taxa on deciduous and coniferous trees, the composition of the guilds was very similar. The individual tree genera, on the other hand, showed significant differences in guild composition, especially when different study areas and years were compared, whereas tree-specific traits, such as tree height, girth in breast height or leaf cover, explained little of the overall variance. On the ordinal level, guild composition also differed significantly between managed and primary forests, with a simultaneous low within-group variability, indicating that management is a key factor determining the distribution of biodiversity and guild composition