Pollinator loss

Various aspects of the pollination biology of the alpine flora of Kosciusko National Park, NSW, were examined from late December 1983 until the end of March 1984, including flowering phenology, corolla tube lengths, flower colour, ultraviolet reflectance patterns, visitation rates to the flowers and proboscis lengths of the flower-visiting insects. An average of 5.3 species flowered in each of 13, 2 m×2 m montane plots and 5.6 species in the 13 alpine plots. The maximum number in flower simultaneously averaged 4.1 species in the montane and 3.3 in the alpine plots; flowering peaked in mid-January, Corolla tube lengths of the flora averaged 1.73 mm.The most common floral colour was white or predominantly white (40 species), followed by yellow (14 species). Only six of the 38 species (16%) examined had some type of reflectance pattern; the remaining species all absobed ultraviolet.Flies appeared to be the major pollinators. The insects collected in the study area comprised 60 species of Diptera, 33 species of Hymenoptera, and several species each of Lepidoptera and Coleoptera. On average, 14.4% of flowers watched during 379 observation periods (10 min each) were visited. On average, each plant species was visited by 6.4 species of flies, 2.4 species of bees, wasps or sawflies, one species of butterfly or moth and 0.3 species of beetles. Visitation rates increased over the growing season, and were significantly affected by ambient temperature (positively), light levels (positively) and wind speed (negatively).The maximum proboscis length for the 25 most common species of bees was 2.76 mm, but 18 of 51 species of flies had proboscis lengths longer than this. The mean proboscis length for all 25 species of bees was 1.68 mm, and for 51 species of flies was 2.31 mm. Proboscis lengths for flies were positively correlated with the average corolla length for the plant species they visited. For bees, however, the range in proboscis lengths was relatively small and did not show this pattern.There appear to be significant differences between the plant-pollinator community of alpine Australia and other alpine areas where bumblebees are common pollinators. These differences include shorter proboscis and corolla tube lengths, and perhaps an increased diversity and significance of flies as pollinators.

The apparent reduction of solitary and
primitively eusocial bees populations has remained a huge
concern over the past few decades and urbanisation is
considered as one of the factors affecting bees at different
scales depending on bee guild. As urbanisation is increasing globally it necessitates more research to understand the complex community dynamics of solitary and primitively eusocial bees in urban settings. We investigated the urban core of a British town for diversity and abundance of solitary bees using standardized methods, and compared the results with nearby meadows and nature reserves. The study recorded 48 species within the town, about 22 % of the total species and 58 % of the genera of solitary bees in the United Kingdom. Furthermore we found the urban core
to be more diverse and abundant in solitary and primitively
eusocial bees compared to the meadows and nature reserves.
Of particular note was an urban record of the nationally
rare Red Data Book species Coelioxys quadridentata and its host Anthophora quadrimaculata. This research demonstrates that urban settings can contribute significantly to the conservation of solitary and
primitively eusocial bees in Britain.

Over the past decades, both wild and domesticated insect pollinators are in dramatic decline, which puts at stake the existence of species, ecosystem resilience and global food security. Globally, 87 of major food crops depend on animal pollination. Together these account for 35 % of the world food production volume. Pollinator mediated crops are indispensable for essential micronutrients in the human diet. Many ornamental plants as well as crops for fibre, fodder, biofuels, timber and phytopharmaceuticals also depend on insect pollinators. This article aims to map the current situation of pollinators worldwide, with a focus on the critical role of pollinators in the human food chain and ecosystem sustainability, their intrinsic and extrinsic value, as well as the causes of their declines and the interventions needed to conserve them, in order to develop an argument for the importance of conserving and restoring pollinator populations and diversity. The present pollinator crisis threatens global and local food security, can worsen the problems of hidden hunger, erodes ecosystem resilience, and can destabilise ecosystems that form our life support system. An integrated approach that simultaneously addresses the key drivers is needed. This includes creation and restoration of floral and nesting resources, a global phase out of prophylactic use of neonicotinoids and fipronil, improvement of test protocols in authorisation of agrochemicals, and restoration and maintenance of independence in regulatory science. The authors argue that an international treaty for global pollinator stewardship and pollinator ecosystem restoration should be initiated in order to systemically counteract the current crisis.

Honeybees are native to Africa and Europe but have been spread worldwide as the basis for an apicultural industry. To date, large and diverse wild populations only remain in Africa. On this continent the beekeeping industry is relatively undeveloped and relies on trapping swarms from wild populations to constitute the managed stocks. Bee breeding is seldom practiced. The situation is therefore different from that of Europe or North America where wild or feral honeybees have almost disappeared and this distinction is important when assessing the conservation status of African honeybees. While African honeybees appear to be more resistant to major diseases, the history of honeybee populations worldwide suggests that their conservation is a necessity. After analyzing the threats to which honeybees are exposed in Africa, we argue that preventive conservation measures are required to maintain the present favorable situation and avoid the declines in populations experienced elsewhere. Die Beziehung zwischen Menschen und Honigbienen hat in Afrika verschiedene Formen: In vielen Ländern wird Honigjagd praktiziert; In einigen Ländern ist die traditionelle Bienenhaltung in Körben oder Klotzbeuten weitverbreitet während andere moderne Bienenhaltungstechnologie einsetzen. Der hauptsächliche kontextuelle Unterschied zu anderen Weltregionen, in denen die Honigbienen entweder heimisch sind oder eingeführt wurden, ist die bedeutende Population von freilebenden Bienen, auf denen Honigjagd und Ausbeutung basieren. Im Gegensatz zu Europa machen bewirtschaftete Völker nur einen kleinen Teil der Honigbienenpopulation aus (14–18 aus 310 Mio). Weiterhin basiert die Bienenhaltung in Afrika weitgehend auf dem Fang von wilden Schwärmen und es wird keine oder nur wenig Bienenzucht betrieben. Diese Unterschiede sind wichtig, wenn die Honigbienenpopulationen von den in anderen Teilen der Welt zu beobachtenden Abnahmen geschützt werden sollen. Für Afrika sollten daher besondere politische Maßnahmen entwickelt werden. Auf diesem Kontinent sind die Netzwerke, auf die sich Bienenhalter und die Bienenindustrie stützen können nur sehr schwach entwickelt, und es wurden nur wenige Untersuchungen über die Honigbienen durchgeführt. Es ist daher sehr schwer, genaue Informationen und Zahlen über den Gesundheitszustand der Honigbienenpopulationen zu erhalten und daraus abzuleiten, ob Schutzmaßnahmen notwendig sind. Angesichts der Größe der Wildpopulation und dem Fehlen von Berichten über Epidemien könnte man schließen, dass die Wildpopulation in Afrika nicht gefährdet ist und daher von den Imkern ausgebeutet werden kann. Obwohl afrikanische Honigbienen den meisten Krankheiten ausgesetzt sind, die weltweit Honigbienen schädigen und sie diesen widerstehen können, sind der Verlust von Habitaten und Bejagung zwei Faktoren, denen europäische Bienen in geringerem Ausmaß ausgesetzt sind (da freilebende Honigbienen praktisch nicht mehr vorkommen und die bewirtschafteten Völker in vom Menschen hergestellten Beuten leben). Diese und andere noch nicht identifizierte Faktoren (z. B. neue Krankheiten) können Honigbienen negativ beeinflussen und ihre Wirkung könnte unter Umständen zu Verlusten in ähnlichem Ausmaß führen, wie sie andernorts beobachtet werden. Um zu verhindern, dass etwas Ähnliches in Afrika passieren kann, schlagen wir die Schaffung und Verbesserung sowie eine effektive Inkraftsetzung von Regulationen vor, die auf eine Erhaltung der afrikanischen Honigbienen abzielen. Da Afrika das Ursprungsland von Apis mellifera darstellt und das einzige Weltgebiet, in dem eine große Wildpopulation erhalten ist, sind Anstrengungen zur Erhaltung nicht nur zum Erhalt von einzigartigen Populationen vonnöten, sondern auch, um das Funktionieren des Ökosystems und der landwirtschaftlichen Produktion sicherzustellen, die beide von den Bestäubungsleistungen der Honigbienen abhängig sind.

Applying Ecological Economics for Biodiversity Conservation
Pensoft Publishers 2009, Sofia/Moscow, 366 p.

Therein:
Rodriguez-Labajos, Beatriz, Spangenberg, Joachim H., Maxim, Laura, Binimelis, Rosa, Kuldna, Piret, Monterroso, Iliana, Peterson, Kaja, Uustal, Meelis (2009). The socio-economics of biodiversity risks: Reasons for and methods of analysis, and their application in case studies: 13-30.

The methods laid out in this chapter are then applied in diverse case studies, and the studies are in return evaluated:

Maxim, Laura, Spangenberg, Joachim H., Monterroso, Iliana, Binimelis, Rosa, Rodriguez-Labajos, Beatriz, Peterson, Kaja, Kuldna, Piret, Uustal, Meelis, Martinez-Alier, Joan (2009). Methods for the socio-economics of biodiversity: lessons from ALARM: 327-366.

Thus the book represents empirically tested best practice approaches of applying socio-economnic research methods to biodiversity conservation.

The way pollinators gather resources may play a key role for buffering their population declines. Social pollinators like bumblebees could adjust their foraging after significant workforce reductions to keep provisions to the colony optimal, especially in terms of pollen diversity and quantity. To test what effects a workforce reduction causes on the foraging for pollen, commercially-acquired colonies of the bumblebee Bombus terrestris were allowed to forage in the field and they were experimentally manipulated by removing half the number of workers. For each bumblebee, the pollen pellets were taxonomically identified with DNA metabarcoding of the ITS2 region followed by a statistical filtering based on ROC curves to filter out underrepresented OTUs. Video cameras and network analyses were employed to investigate changes in foraging strategies and behaviour. After filtering out the false-posi-tives, HTS metabarcoding yielded a high plant diversity in the pollen pellets; for plant identity and pollen quantity traits no differences emerged between samples from treated and from control colonies, suggesting that plant choice was influenced mainly by external factors such as the plant phenology. The colonies responded to the removal of 50% of their workers by increasing the foraging activity of the remaining workers, while only negligible changes were found in diet breadth and indices describing the structure of the pollen transport network. Therefore, a consistency in the bumblebees' feeding strategies emerges in the short term despite the lowered workforce.

Many ecosystem services are delivered by organisms that depend on habitats that are segregated spatially or temporally from the location where services are provided. Management of mobile organisms contributing to ecosystem services requires consideration not only of the local scale where services are delivered, but also the distribution of resources at the landscape scale, and the foraging ranges and dispersal movements of the mobile agents. We develop a conceptual model for exploring how one such mobile-agent-based ecosystem service (MABES), pollination, is affected by land-use change, and then generalize the model to other MABES. The model includes interactions and feedbacks among policies affecting land use, market forces and the biology of the organisms involved. Animal-mediated pollination contributes to the production of goods of value to humans such as crops; it also bolsters reproduction of wild plants on which other services or service-providing organisms depend. About one-third of crop production depends on animal pollinators, while 60–90% of plant species require an animal pollinator. The sensitivity of mobile organisms to ecological factors that operate across spatial scales makes the services provided by a given community of mobile agents highly contextual. Services vary, depending on the spatial and temporal distribution of resources surrounding the site, and on biotic interactions occurring locally, such as competition among pollinators for resources, and among plants for pollinators. The value of the resulting goods or services may feed back via market-based forces to influence land-use policies, which in turn influence land management practices that alter local habitat conditions and landscape structure. Developing conceptual models for MABES aids in identifying knowledge gaps, determining research priorities, and targeting interventions that can be applied in an adaptive management context.

Pollination is an ecological process that provides important services to humans. Pollination service in agroecosystems depends on several factors, including the land management systems used by farmers. Here we focused on the effects of insect pollinator diversity on coffee fruit production along a gradient of management systems in central Veracruz, Mexico. The gradient ranged from low environmental impact management systems (the native forest is not completely removed) to high environmental impact management systems (the native forest is completely removed). We hypothesized that pollinator diversity should be higher in low-impact systems. Then, if fruit production is positively related to pollinator diversity, plantations with low-impact management systems should display higher fruit production than plantations with high-impact management systems. We used observational and experimental data to test this hypothesis. Our results indicated that low-impact management systems have higher species richness and relative diversity (measured with the Shannon-Wiener diversity index) of pollinators than high-impact management systems. In all cases, fruit production was positively related with species richness and diversity of pollinators. Moreover, fruit production was higher in low-impact than in high-impact management systems. These results suggest that the diversity of insect pollinators can be influenced by the management system applied by farmers, and that such effects may have strong consequences on coffee fruit production.