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In order to assess the potential value of differently managed cacao plantations for bird conservation on Sulawesi, we surveyed birds in near-primary forest (with limited timber and rattan extraction, and some hunting), cacao plantations with remnant forest trees and plantations lacking forest trees, from February to April 2007. A total of 16 50 x 50 m plots were visited twice and records of 87 species were obtained. Bird species richness and the number of endemics and forest specialists decreased along this gradient of forest conversion, with 20% of the forest specialists, among them 10 endemics, exclusively found in forest. Species composition changed dramatically between habitat types. Sorensen indices showed a similarity of species composition between forests and plantations of 45–60% for forest specialists and 65–71% for all species. The most important environmental variable for the diversity and composition of birds was the number of remnant rainforest trees present in the plantations. Our results suggest that large, undisturbed rainforest are most important for the conservation of forest specialists and endemics but that cacao plantations, if managed to maintain a high and diverse cover of forest trees, can harbour up to 60% of forest specialists and endemics.

Aim Animal communities can be influenced by the composition of the surrounding landscape through immigration. Depending on habitat preferences, however, the effect of the landscape matrix can be positive or negative and can vary with scale. We tested this idea with arable spiders and tried to infer dispersal distances from relationships between local density and landscape composition at different spatial scales. Location Thirty-eight landscapes around the cities of Gottingen and Giessen, Germany. Methods Spiders were captured with pitfall traps in one field of winter wheat in each landscape. Landscape composition around the fields was characterized at 11 scales from 95 m to 3 km radius by land-use mapping and subsequent GIS analysis. Correlation tests were performed between landscape composition and local densities or species richness. Results In both study regions, local species richness was enhanced by non-crop habitats on a landscape scale. The overall densities of wolf spiders (Lycosidae), long-jawed spiders (Tetragnathidae), crab spiders (Thomisidae), and dwarf sheet spiders (Hahniidae) increased significantly in landscapes with high percentages of non-crop habitats. Out of the 40 species tested, 19 responded positively to the percentage of non-crop habitats in the surrounding landscape, and five responded negatively. Depending on the species, the spatial scales with the highest explanatory power ranged from 95 m to 3 km radius around the study fields, potentially reflecting dispersal distances. Main conclusions Arable spider species showed contrasting responses to the landscape context with respect both to the direction and to the spatial scale of the relationship. The variation in landscape requirements among species ensures high spider densities in a wide range of situations, which contributes to ecosystem resilience. However, species richness of arable spiders depends on heterogeneous landscapes with high percentages of non-crop habitats.

1. Data from parasitoids attacking galls of Giraudiella inclusa Fr. (Diptera: Cecidomyiidae) from Phragmites australis Trin. were used to assess the factors dictating species richness and coexistence in a community. 2. Species richness of the 14 parasitoids could be related to the high frequency and apparency of both the galls and the Phragmites monocultures. Four non-galling species of Cecidomyiidae attacking P. australis had only 2-3 parasitoid species, presumably due to the less visible and less heterogeneous microhabitat offered to the parasitoids. 3. Distribution of midge galls was due to several plant characteristics with percentage parasitism and parasitoid coexistence determined by the site of gall induction. The stem-boring moth Archanara geminipuncta Haw. (Lepidoptera: Noctuidae) was a key factor for the heterogeneous gall distribution and thereby favoured coexistence of the galls' parasitoid species: Giraudiella-galls induced on side shoots, grown from Archanara-damaged shoots, increased percentage parasitism of two parasitoid species and reduced parasitism of one species. 4. Parasitoid foraging was concentrated on temporally and spatially separated subpopulations with the microscale of host density (gall cluster size per reed internode) influencing percentage parasitism only in two out of eight species, and with the macroscale (gall abundance per habitat) having no effect at all. These findings do not meet expectations for density-dependent host regulation, but support a resource heterogeneity hypothesis. Both midge and parasitoid populations appeared to be 'limited from below' rather than 'controlled from above'. 5. The prediction that host density is negatively correlated with parasitoid diversity was not supported.

Flush-crash cycles of the monophagous and univoltine moth Archanara geminipuncta, which greatly damages the silicate-rich shoots of common reed P. australis, showed a non-equilibrium nature of population fluctuations in this late-successional, apparent, and undistrubed grass monoculture. The striking similarities to pest outbreaks in crops (early successional plants in man-made pure stands) are discussed (...)

Im Winter 1981/82 wurden in der Umgebung Osnabrucks (Niedersachsen) 43 Vogelnester von 4 unterschiedlichen Standorten im Labor auf ihren Insekten- und Spinnenbestand analysiert. Das aktive Aufsuchen von Vogelnestern als kleinklimatisch gunstige Uberwinterungsorte war bei vielen Arten mit einem Straten- und Biotopwechsel verbunden. Bei folgenden Spinnenarten konnten erstmals winterreife Imagines nachgewiesen werden:Lathys humilis (Blackwall),Theridion tinctum (Walckenaer),Poeciloneta globosa (Wider) unPityohyphantes phrygianus (Koch). Die Naturschutz-Bedeutung verlassener Vogelnester als attraktive Refugien uberwinternder Arthropoden wird diskutiert.

Due to increasing human modification of tropical landscapes, the relative importance of natural habitats and agricultural systems has become a major conservation topic to counteract global species loss. We investigated the contribution of tropical primary forest, cacao agroforestry systems of varying management practices and openland to the temporal and spatial variation of diversity of native bee communities in the herb layer (Apidae, Hymenoptera) in Sulawesi (Indonesia). Local bee density and diversity were highest in openland, followed by agroforestry systems and were lowest in primary forests, revealing the importance of herbaceous food resources in the understorey. In contrast, highest regional bee richness was found in agroforestry systems, because of high community dissimilarity. Multidimensional scaling supported these findings with openland habitats showing more compactly clustered bee species communities than agroforestry habitats. In conclusion, the herb associated bee community profited from the opening of the landscape as a result of agricultural activities, while agroforestry systems increased bee species richness especially on a regional scale due to high management diversity. peerReviewed

Agricultural intensification (AI) is currently a major driver of biodiversity loss and related ecosystem functioning decline. However, spatio-temporal changes in community structure induced by AI, and their relation to ecosystem functioning, remain largely unexplored. Here, we analysed 16 quantitative cereal aphid–parasitoid and parasitoid–hyperparasitoid food webs, replicated four times during the season, under contrasting AI regimes (organic farming in complex landscapes vs. conventional farming in simple landscapes). High AI increased food web complexity but also temporal variability in aphid–parasitoid food webs and in the dominant parasitoid species identity. Enhanced complexity and variability appeared to be controlled bottom-up by changes in aphid dominance structure and evenness. Contrary to the common expectations of positive biodiversity–ecosystem functioning relationships, community complexity (food-web complexity, species richness and evenness) was negatively related to primary parasitism rates. However, this relationship was positive for secondary parasitoids. Despite differences in community structures among different trophic levels, ecosystem services (parasitism rates) and disservices (aphid abundances and hyperparasitism rates) were always higher in fields with low AI. Hence, community structure and ecosystem functioning appear to be differently influenced by AI, and change differently over time and among trophic levels. In conclusion, intensified agriculture can support diverse albeit highly variable parasitoid–host communities, but ecosystem functioning might not be easy to predict from observed changes in community structure and composition. Electronic supplementary material The online version of this article (doi:10.1007/s00442-012-2366-0) contains supplementary material, which is available to authorized users.

Knowledge on phenological, morphometric, and phytochemical variation of local progenies of European aspen (Populus tremula, L.) is limited. The goal of this study was to characterize variation in growth and ecologically important leaf properties in aspen full-sib families in relation to interacting organisms (mycorrhiza, endophytes, and insects) and to determine whether these interactions were affected by soil application of a systemic fungicide. In local progenies, within-family variation of neutral molecular genetic markers (nuclear microsatellites) was higher than between families. Significant variation in growth, production of phenolic defensive compounds and other phytochemical leaf traits was found between families. Phenolic compounds showed clear negative correlation with generalist herbivores, but did not result in negative trade-off with biomass production. Differences in mycorrhizal colonization were not found among full-sib families and application of a systemic fungicide suppressed neither mycorrhizal colonization nor infestation with insects. However, a strong suppression of endophytes occurred, whose long-term consequences may require attention when fungicides are used in agroforestry plantations. peerReviewed

Variability within and between shoots of the grass Phragmites australis proved to be important for both survival (successful gall induction) and reproduction (larval weight) of the gall-inducing midge Giraudiella inclusa. The ovipositing females and the migrating first instar larvae chose a predictable microhabitat within shoots and within internodes characterized by a high nutritional quality (nitrogen, mineral content, sugar, water) and reduced palnt defense properties (silicate). Clutch size increased with the shoot diameter, larval scramble competition could not be detected. Female shoot selection was random, although the chances of successful gall induction greatly differed between shoots. Thick and intact shoots (≥6 mm) led to a high larval mortality. But thick shoots destroyed apically by stem-mining caterpillars (of the noctuid moth Archanara geminipuncta) had on average large gall clusters. Accordingly, the adjustment of the clutch size to the shoot diameter resulted in an advantage for the gall midge females only when shoots were thin and short (i.e. stressed by water and nutrient deficiency) or heavily damage (i.e. stressed) by caterpillars. Thus, the monophagous gall maker G. inclusa did not compensate for all features of intershoot variation of P. australis, although grasses are well-known for their simple plant architecture and their low diversity and low concentration of secondary compounds.

Biodiversity conservation through land-use systems on private land is becoming a pressing environmental policy issue. Agroforestry, such as shade-coffee production, contributes to biodiversity conservation. However, falling coffee prices force many coffee growers to convert their sites into economically more attractive land uses. We performed an economic evaluation of coffee pollination by bees in two distinct tropical regions: an area of low human impact with forests neighboring agroforestry in Indonesia and an area of high human impact with little remaining forest in Ecuador. We evaluated bee pollination for different forest-destruction scenarios, where coffee yields depend on forests to provide nesting sites for bees. We used two novel approaches. First, we examined how coffee net revenues depend on the pollination services of adjacent forests by considering berry weight in addition to fruit set, thereby providing a comprehensive evaluation. Second, we determined the net welfare effects of land-use changes, including the fact that former forestland is normally used for alternative crops. In both regions, crop revenues exceeded coffee pollination values, generating incentives to convert forests, even if owners would be compensated for pollination services. The promotion of certified "biodiversity-friendly" coffee is a feasible option to maintain shade-coffee systems. This is of special importance in high-impact areas where only small forest fragments remain. We conclude that a comprehensive economic analysis is necessary to adequately evaluate rainforest preservation for the enhancement of ecosystem services, such as pollination.

Evidence for interspecific competition between honey bees and wild bees was studied on 15 calcareous grasslands with respect to: (1) foraging radius of honey bees, (2) overlap in resource use, and (3) possible honey bee effects on species richness and abundance of flower-visiting, ground-nesting and trap-nesting wild bees. The grasslands greatly differed in the number of honey bee colonies within a radius of 2 km and were surrounded by agricultural habitats. The number of flower-visiting honey bees on both potted mustard plants and small grassland patches declined with increasing distance from the nearest apiary and was almost zero at a distance of 1.5-2.0 km. Wild bees were observed visiting 57 plant species, whereas honey bees visited only 24 plant species. Percentage resource overlap between honey bees and wild bees was 45.5%, and Hurlbert's index of niche overlap was 3.1. In total, 1849 wild bees from 98 species were recorded on the calcareous grasslands. Neither species richness nor abundance of wild bees were negatively correlated with the density of honey bee colonies (within a radius of 2 km) or the density of flower-visiting honey bees per site. Abundance of flower- visiting wild bees was correlated only with the percentage cover of flowering plants. In 240 trap nests, 1292 bee nests with 6066 brood cells were found. Neither the number of bee species nor the number of brood cells per grassland was significantly correlated with the density of honey bees. Significant correlations were found only between the number of brood cells and the percentage cover of shrubs. The number of nest entrances of ground-nesting bees per square metre was not correlated with the density of honey bees but was negatively correlated with the cover of vegetation. Interspecific competition by honey bees for food resources was not shown to be a significant factor determining abundance and species richness of wild bees.

Die seltene Rote GespinstblattwespeCaenolyda reticulata (L.) wurde in jungster Zeit an 3 Orten in Norddeutschland gefunden. Zu den Bereichen Parthenogenese, Synanthropie und Einstufung in Rote Listen erfolgt eine kurze Diskussion.

Subtle changes in shoot growth over and above the well-known gall induction were tested using four generations of the gall-inducing midge Giraudiella inclusa developing in grain-like galls inside the internodes of the grass Phragmites australis. Larval influence on host plant growth (1) was not restricted to gall development, and (2) did not cause the usually expected internode and shoot shortening, but led to an elongation of the attacked internode and to predictable alterations in the length of the internodes adjoing the attacked sites. Patterns of variation in length depended on the sequence number of the attacked internode and the seasonal direction of assimilate flow. Basal shoot diameter was negatively and the number of galls per internode positively correlated with the degree of elongation. Gall induction, local biomass and nutrient increase, internode elongation, and the increase of clutch size with shoot diameter are presumably advantageous for the immobile gall midge larvae, and may explain why intraspecific larval competition was not detected. Shoot elongation (7% to 11%) is expected to enhance both survival and productivity of attacked shoots because of the extreme competition for light in Phragmites habitats. Thin and short shoots stressed by water and nutrient deficiency were less resistant to gall midge attack and showed greater elongation than thick panicle shoots, so that the outcome for both the gall midge and the infested thin shoots appeared to be improved. The results support and expand the "nutrition hypothesis" on the adaptive nature of galls, in that not only gall induction in itself, but also the midge influence on resource flow and internode growth is presumed to benefit the parasite.

The role of plant stress and shoot damage in the population dynamics of a grassinhabiting gall maker was assessed in the field. Four generations of Giraudiella inclusa (Diptera, Cecidomyiidae), developing in grain-like galls inside the internodes of common reed Phragmites australis, were sampled from nine habitats in northern West Germany from 1981 to 1984. Thin shoots of dry reed, stressed by water and nutrient deficiency, contained less silicate, caused less mortality of gall-inducing first instar larvae and had higher gall abundance than thick and intact shoots of wet reed. Thick shoots damaged by the stem-boring moth Archanara geminipuncta (Lepidoptera, Noctuidae) developed narrow side shoots that were highly susceptible to attack of the 2nd to 4th midge generation, thereby causing an increase of egg survival and gall abundance. Such facilitation among herbivores is a poorly known type of food web interaction. Differentiation between dry and wet reed and number of side shoots m-2 explained 92% of the variation of midge gall abundance between habitats and years. Availability of susceptible food, easily measurable by shoot characters, was the key factor in midge population dynamics.

Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015. The collation of biodiversity datasets with broad taxonomic and biogeographic extents is necessary to understand historical declines and to project - and hopefully avert - future declines. We describe a newly collated database of more than 1.6 million biodiversity measurements from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. © 2014 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.