Risks to pollinators and pollination from invasive alien species

Invasive alien species modify pollinator biodiversity and the services they provide that underpin ecosystem function and human well-being. Building on the Intergovernmental Science-Policy Platform for Biodiversity and Ecosystem Services (IPBES) global assessment of pollinators and pollination, we synthesize current understanding of invasive alien impacts on pollinators and pollination. Invasive alien species create risks and opportunities for pollinator nutrition, re-organize species interactions to affect native pollination and community stability, and spread and select for virulent diseases. Risks are complex but substantial, and depend greatly on the ecological function and evolutionary history of both the invader and the recipient ecosystem. We highlight evolutionary implications for pollination from invasive alien species, and identify future research directions, key messages and options for decision-making

A common framework for identifying linkage rules across different types of interactions

Species interactions, ranging from antagonisms to mutualisms, form the architecture of biodiversity and determine ecosystem functioning. Understanding the rules responsible for who interacts with whom, as well as the functional consequences of these interspecific interactions, is central to predict community dynamics and stability. Species traits sensu lato may affect different ecological processes by determining species interactions through a two-step process. First, ecological and life-history traits govern species distributions and abundance, and hence determine species co-occurrence and the potential for species to interact. Secondly, morphological or physiological traits between co-occurring potential interaction partners should match for the realization of an interaction. Here, we review recent advances on predicting interactions from species co-occurrence and develop a probabilistic model for inferring trait matching. The models proposed here integrate both neutral and trait-matching constraints, while using only information about known interactions, thereby overcoming problems originating from undersampling of rare interactions (i.e. missing links). They can easily accommodate qualitative or quantitative data and can incorporate trait variation within species, such as values that vary along developmental stages or environmental gradients. We use three case studies to show that the proposed models can detect strong trait matching (e.g. predator‿prey system), relaxed trait matching (e.g. herbivore‿plant system) and barrier trait matching (e.g. plant‿pollinator systems). Only by elucidating which species traits are important in each process (i.e. in determining interaction establishment and frequency), we can advance in explaining how species interact and the consequences of these interactions for ecosystem functioning. A lay summary is available for this articlePeer Reviewe

Diversidad o dominancia en la producción de alimentos? : el caso de los polinizadores

Garibaldi, Lucas Alejandro. Universidad Nacional de Río Negro (UNRN). Instituto de Investigaciones en Recursos Naturales. Agroecología y Desarrollo Rural (IRNAD). Río Negro, Argentina.Aguiar, Sebastián. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA). Laboratorio de Análisis Regional y Teledetección (LART) Buenos Aires, Argentina.Aizen, Marcelo A. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Instituto de Investigaciones en Biodiversidad y Medio Ambiente (INIBIOMA). Laboratorio Ecotono. San Carlos de Bariloche, Río Negro, Argentina.Morales, Carolina L. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Instituto de Investigaciones en Biodiversidad y Medio Ambiente (INIBIOMA). Laboratorio Ecotono. San Carlos de Bariloche, Río Negro, Argentina.Sáez, Agustín. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Instituto de Investigaciones en Biodiversidad y Medio Ambiente (INIBIOMA). Laboratorio Ecotono. San Carlos de Bariloche, Río Negro, Argentina.340-347La biodiversidad está siendo destruida a una tasa alarmante. Una de las principales causas de esta pérdida es el cambio de uso del suelo, que se basa en la agricultura y la ganadería convencionales. Las prácticas de manejo como el monocultivo y el uso intensivo de agroquímicos reducen el número de especies de plantas, aves, insectos y otros grupos taxonómicos, a la vez que aumentan la abundancia relativa (dominancia) de pocas especies cultivadas y silvestres (e.g., malezas). Dado que casi 40% de la superficie terrestre se destina a la producción de cultivos y de carne, es clave lograr una producción agropecuaria compatible con la preservación de la biodiversidad. Además de su valor por aspectos éticos, espirituales y de uso para generaciones futuras, en este artículo destacamos el rol de la biodiversidad en la producción agropecuaria, y usamos a los polinizadores como ejemplo. Paradójicamente, la agricultura convencional está destruyendo la diversidad de polinizadores, pero esta diversidad es fundamental para incrementar la productividad (y su estabilidad en tiempo y espacio) de muchos cultivos. Varios estudios demuestran que la pérdida de diversidad de polinizadores no se puede compensar con una abundancia alta de una sola especie de polinizador (dominancia). Es por ello que debatimos acciones que pueden tomar los productores, consumidores, políticos y científicos para recuperar parte de esta biodiversidad. Por ejemplo, los productores pueden implementar prácticas dentro y fuera del cultivo para aumentar los recursos florales y de nidificación a los polinizadores y, de este modo, promover su abundancia y diversidad. Además, los consumidores pueden modificar su dieta, reducir los desperdicios y producir alimentos a pequeña escala, entre otras acciones. Como consecuencia, resulta imperioso tomar acciones múltiples por todos los actores, pues una sola estrategia no será suficiente para resolver el dilema de producir y conservar la biodiversidad

The economic cost of losing native pollinator species for orchard prodution

The alarming loss of pollinator diversity world‐wide can reduce the productivity of pollinator‐dependent crops, which could have economic impacts. However, it is unclear to what extent the loss of a key native pollinator species affects crop production and farmer's profits. By experimentally manipulating the presence of colonies of a native bumblebee species Bombus pauloensis in eight apple orchards in South Argentina, we evaluated the impact of losing natural populations of a key native pollinator group on (a) crop yield, (b) pollination quality, and (c) farmer's profit. To do so, we performed a factorial experiment of pollinator exclusion (yes/no) and hand pollination (yes/no). Our results showed that biotic pollination increased ripe fruit set by 13% when compared to non‐biotic pollination. Additionally, fruit set and the number of fruits per apple tree was reduced by less than a half in those orchards where bumblebees were absent, even when honeybees were present at high densities. Consequently, farmer's profit was 2.4‐fold lower in farms lacking bumblebees than in farms hosting both pollinator species. The pollination experiment further suggested that the benefits of bumblebees could be mediated by improved pollen quality rather than quantity. Synthesis and applications. This study highlights the pervasive consequences of losing key pollinator functional groups, such as bumblebees, for apple production and local economies. Adopting pollinator‐friendly practices such as minimizing the use of synthetic inputs or restoring/maintaining semi‐natural habitats at farm and landscape scales, will have the double advantage of promoting biodiversity conservation, and increasing crop productivity and profitability for local farmers. Yet because the implementation of these practices can take time to deliver results, the management of native pollinator species can be a provisional complementary strategy to increase economic profitability of apple growers in the short term.info:eu-repo/semantics/acceptedVersio

Invasive Mutualists Erode Native Pollination Webs

Plant–animal mutualisms are characterized by weak or asymmetric mutual dependences between interacting species, a feature that could increase community stability. If invasive species integrate into mutualistic webs, they may alter web structure, with consequences for species persistence. However, the effect of alien mutualists on the architecture of plant–pollinator webs remains largely unexplored. We analyzed the extent of mutual dependency between interacting species, as a measure of mutualism strength, and the connectivity of 10 paired plant–pollinator webs, eight from forests of the southern Andes and two from oceanic islands, with different incidences of alien species. Highly invaded webs exhibited weaker mutualism than less-invaded webs. This potential increase in network stability was the result of a disproportionate increase in the importance and participation of alien species in the most asymmetric interactions. The integration of alien mutualists did not alter overall network connectivity, but links were transferred from generalist native species to super-generalist alien species during invasion. Therefore, connectivity among native species declined in highly invaded webs. These modifications in the structure of pollination webs, due to dominance of alien mutualists, can leave many native species subject to novel ecological and evolutionary dynamics

A global synthesis reveals biodiversity-mediated benefits for crop production

Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield–related ecosystem services can be maintained by a few dominant species or rely on high richness remains unclear. Using a global database from 89 studies (with 1475 locations), we partition the relative importance of species richness, abundance, and dominance for pollination; biological pest control; and final yields in the context of ongoing land-use change. Pollinator and enemy richness directly supported ecosystem services in addition to and independent of abundance and dominance. Up to 50% of the negative effects of landscape simplification on ecosystem services was due to richness losses of service-providing organisms, with negative consequences for crop yields. Maintaining the biodiversity of ecosystem service providers is therefore vital to sustain the flow of key agroecosystem benefits to society.EEA ConcordiaFil: Dainese, Matteo. Eurac Research. Institute for Alpine Environment; ItaliaFil: Dainese, Matteo. University of Würzburg. Biocenter. Department of Animal Ecology and Tropical Biology; AlemaniaFil: Martin, Emily A. University of Würzburg. Biocenter. Department of Animal Ecology and Tropical Biology; AlemaniaFil: Aizen, Marcelo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Aizen, Marcelo Adrian. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina.Fil: Albrecht, Matthias. Agroscope. Agroecology and Environment; SuizaFil: Bartomeus, Ignasi. CSIC. Estación Biológica de Doñana. Integrative Ecology; EspañaFil: Bommarco, Riccardo. Swedish University of Agricultural Sciences. Department of Ecology; SueciaFil: Carvalheiro, Luisa G. Universidade Federal de Goias. Departamento de Ecologia; BrasilFil: Carvalheiro, Luisa G. Universidade de Lisboa. Faculdade de Ciencias. Centre for Ecology, Evolution and Environmental Changes (CE3C); PortugalFil: Chaplin-Kramer, Rebecca. Stanford University. Natural Capital Project; Estados UnidosFil: Gagic, Vesna. Commonwealth Scientific and Industrial Research Organisation (CSIRO); AustraliaFil: Garibaldi, Lucas Alejandro. Universidad Nacional de Rio Negro. Instituto de Investigaciones de Recursos Naturales, Agroecología y Desarrollo Rural; ArgentinaFil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cavigliasso, Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Steffan-Dewenter, Ingolf. University of Würzburg. Biocenter. Department of Animal Ecology and Tropical Biology; Alemani

Interactive Effects of Large- and Small-Scale Sources of Feral Honey-Bees for Sunflower in the Argentine Pampas

Pollinators for animal pollinated crops can be provided by natural and semi-natural habitats, ranging from large vegetation remnants to small areas of non-crop land in an otherwise highly modified landscape. It is unknown, however, how different small- and large-scale habitat patches interact as pollinator sources. In the intensively managed Argentine Pampas, we studied the additive and interactive effects of large expanses (up to 2200 ha) of natural habitat, represented by untilled isolated “sierras”, and narrow (3–7 m wide) strips of semi-natural habitat, represented by field margins, as pollinator sources for sunflower (Helianthus annus). We estimated visitation rates by feral honey-bees, Apis mellifera, and native flower visitors (as a group) at 1, 5, 25, 50 and 100 m from a field margin in 17 sunflower fields 0–10 km distant from the nearest sierra. Honey-bees dominated the pollinator assemblage accounting for >90% of all visits to sunflower inflorescences. Honey-bee visitation was strongly affected by proximity to the sierras decreasing by about 70% in the most isolated fields. There was also a decline in honey-bee visitation with distance from the field margin, which was apparent with increasing field isolation, but undetected in fields nearby large expanses of natural habitat. The probability of observing a native visitor decreased with isolation from the sierras, but in other respects visitation by flower visitors other than honey-bees was mostly unaffected by the habitat factors assessed in this study. Overall, we found strong hierarchical and interactive effects between the study large and small-scale pollinator sources. These results emphasize the importance of preserving natural habitats and managing actively field verges in the absence of large remnants of natural habitat for improving pollinator services

Beyond species loss: The extinction of ecological interactions in a changing world

© 2014 The Authors. The effects of the present biodiversity crisis have been largely focused on the loss of species. However, a missed component of biodiversity loss that often accompanies or even precedes species disappearance is the extinction of ecological interactions. Here, we propose a novel model that (i) relates the diversity of both species and interactions along a gradient of environmental deterioration and (ii) explores how the rate of loss of ecological functions, and consequently of ecosystem services, can be accelerated or restrained depending on how the rate of species loss covaries with the rate of interactions loss. We find that the loss of species and interactions are decoupled, such that ecological interactions are often lost at a higher rate. This implies that the loss of ecological interactions may occur well before species disappearance, affecting species functionality and ecosystems services at a faster rate than species extinctions. We provide a number of empirical case studies illustrating these points. Our approach emphasizes the importance of focusing on species interactions as the major biodiversity component from which the 'health' of ecosystems depends.Peer Reviewe