Pollinators

The present experiment was carried out to study biodiversity,
frequency and effect of pollinators in the production of pods and grains in soybean (Glycine max L. Merrill), var. ‘Mon Soy 3329’. Two treatments were used (covered with clarite area and open area) so that bugs could visit them freely. Among the bugs, which come to visit soybean flowers, Apis mellifera species was the most frequent visitor (84.93%), followed by Lepidoptera (5.75%), Diabrotica speciosa (2.74%), Lagria villosa (Coleoptera: Lagriidae – 2.47%), wasps (Hymenoptera: Vespidae – 2.47%), Trigona sp. (Hymenoptera: Apidae – 0.82%) and others (0.82%). The number of pods per plant and number of seeds per plant did not show difference in covered and open areas, however, the total weight of seeds per plant and the weight of each seed were the greatest ones (43.68%) in open area (23.69g) than covered one (16.49g), with an increase of 44.45% and 50.42%, respectively, in relation to the open area without honeybees. In open area, the number of pods with one seed was 180% bigger (p <0.05) and the pods with three seeds were 31.93% smaller (p< 0.05) when compared with plants in covered area. The soybeans flowers are attractive to Africanized honeybees that contribute with this plant pollination.

1. Medio Físico
1.1. CAPITULO 1. Historia y situación actual de la Reserva de la Biósfera Ría Lagartos
Cristóbal E. Cáceres G. Cantón y Rafael Robles de Benito.........................................................................14
1.2. CAPITULO 2. El medio físico: Clima, geoformas, suelos y agua
Francisco Bautista, Jorge Leirana, Yameli Aguilar, Carmen Delgado y Oscar Frausto................................21
1.3. CAPITULO 3. Estado de conservación de la vegetación
Sachiko Chiriguchi Murayama y Luis Salinas-Peba......................................................................................41
1.4. CAPITULO 4. Hidrocarburos en sedimentos recientes
Pedro F. Góngora-Góngora, Víctor M. Cobos-Gasca y Roberto C. Barrientos-Medina...............................68
2. Medio Biótico
2.1. CAPITULO 5. Estructura de la vegetación de la selva baja caducifolia y de la selva baja
inundable
Patricia Guadarrama, Luis Salinas-Peba y Silvia Castillo-Argüero..............................................................87
2.2. CAPITULO 6. Fenología de floración y visitantes florales de especies herbáceas
Víctor Parra-Tabla, Luis Abdala-Roberts Patricia Téllez, Nataly Celaya, Luis Salinas-Peba y Conchita
Alonso..........................................................................................................................................................105
2.3. CAPITULO 7. Tres especies de arbustos como “constructoras” de hábitat en el matorral
costero
Jorge L. Leirana Alcocer, Luisa A. Ríos Candila, Francisco Bautista, Jorge A. Navarro Alberto y Manuel B.
Crespo.........................................................................................................................................................123
2.4. CAPITULO 8. Respuestas ecofisiológicas de plantas cactáceas: Fijación de CO2,
productividad y supervivencia
J. Carlos Cervera Herrera, Raiza J. Castillo Argáez e Irving R. Vargas Solís..............................................140
2.5. CAPITULO 9. Hongos micorrizógenos: organismos clave para la vegetación
José Ramos-Zapata, Patricia Guadarrama, Laura Hernández-Cuevas, Luís A. Salinas Escobar, Ángel
Patrón, Gema Galindo-Flores, Alejandro Kong-Luz, Guadalupe Santiago-Martínez y Rosabel Juárez
Barradas.....................................................................................................................................................160
3. Biodiversidad
3.1. CAPITULO 10. Diversidad de insectos parasitoides: avispas Ichneumonidae
Alejandra González-Moreno, Hugo Delfín-González y Santiago Bordera...................................................179
3.2. CAPITULO 11. Riqueza y abundancia de los murciélagos en las selvas secas
Celia Sélem-Salas y Juan Tun-Garrido........................................................................................................195
3.3. CAPITULO 12. Las poblaciones de cocodrilianos (Crocodylus acutus y C. moreletti)
Mitzi A. Olvera-Morales, Roberto C. Barrientos-Medina, José R. Cedeño-Vázquez, Jorge A.
Navarro- Alberto y Felipe G. Be-Estrella.....................................................................................................207
3.4. CAPITULO 13. Los peces continentales
Roberto C. Barrientos-Medina, Alejandra Aguillón-Negreros y Lizbeth Chumba-Segura..........................219
4. Interacciones Bióticas
4.1. CAPITULO 14. Visitantes florales y redes de interacción planta–polinizador
María José Campos Navarrete, Rommel Moo Aldana, José Ramos Zapata y Víctor Parra Tabla.............231
4.2. CAPITULO 15. Interacciones planta-colibrí en la duna costera
Pamela Medina y Víctor Parra-Tabla...........................................................................................................249
4.3. CAPITULO 16. Interacción planta-hongos benéficos en la restauración de la vegetación de
duna costera
José A. Ramos-Zapata, Ricardo Aldana Blanco y Patricia Guadarrama Chávez.......................................266
4.4. CAPITULO 17. Murciélagos frugívoros y polinectarívoros
Celia Selem-Salas, Juan Tun-Garrido J, Lorena Tzab-Hernández y Miguel Peña-Tun...............................281

Wild and managed pollinators provide a wide range of benefits to society in terms of contributions to food security, farmer and beekeeper livelihoods, social and cultural values, as well as the maintenance of wider biodiversity and ecosystem stability. Pollinators face numerous threats, including changes in land-use and management intensity, climate change, pesticides and genetically modified crops, pollinator management and pathogens, and invasive alien species. There are well-documented declines in some wild and managed pollinators in several regions of the world. However, many effective policy and management responses can be implemented to safeguard pollinators and sustain pollination services.

Insect pollination constitutes an ecosystem service of global importance, providing significant economic and aesthetic benefits as well as cultural value to human society, alongside vital ecological processes in terrestrial ecosystems. It is therefore important to understand how insect pollinator populations and communities respond to rapidly changing environments if we are to maintain healthy and effective pollinator services. This chapter considers the importance of conserving pollinator diversity to maintain a suite of functional traits and provide a diverse set of pollinator services. We explore how we can better understand and mitigate the factors that threaten insect pollinator richness, placing our discussion within the context of populations in predominantly agricultural landscapes in addition to urban environments. We highlight a selection of important evidence gaps, with a number of complementary research steps that can be taken to better understand: (i) the stability of pollinator communities in different landscapes in order to provide diverse pollinator services; (ii) how we can study the drivers of population change to mitigate the effects and support stable sources of pollinator services and (iii) how we can manage habitats in complex landscapes to support insect pollinators and provide sustainable pollinator services for the future. We advocate a collaborative effort to gain higher quality abundance data to understand the stability of pollinator populations and predict future trends. In addition, for effective mitigation strategies to be adopted, researchers need to conduct rigorous field testing of outcomes under different landscape settings, acknowledge the needs of end-users when developing research proposals and consider effective methods of knowledge transfer to ensure effective uptake of actions.

For a diverse pollinator fauna it is important that pollen and nectar are available over the entire summer at spatially relevant scales. Semi-natural hay meadows are among the most important sources of flower resources for pollinators, but the resources are strongly affected by the timing of mowing. Management recommendations for hay meadows often prescribe late mowing on order to allow undisturbed flowering during most of the summer. Traditional practices, however, often include also earlier mowing. We investigate the link between the temporal variation of flower resources and traditional mowing practices of semi-natural hay meadows in a low-intensity agricultural landscape in Romania. In early August, we botanically surveyed meadows that were cut early, intermediately, or late in the season. We recorded all herb species, their phenological stage, and the number of reproductive units of each species. Data were analysed using DCA, LM and GLM. Plant species richness and composition are not affected by the time of mowing, but different sets of species flower in semi-natural grasslands with different mowing regimes. In August the proportion of species flowering and flower density are highest in the early-mown meadows due to re-flowering after mowing. Analyses of phenological stages indicate that late-mown meadows are the main pollen and nectar sources in July, whereas meadows mown early are the main resource from August to the end of the season. The results demonstrate that for pollinator conservation, heterogeneous mowing times within a landscape need to be encouraged when possible, and that strict focus on late mowing may lead to shortage of flower resources late in the summer. Studies of low-intensity agriculture has a great potential for learning about management methods that can be used in other parts of the world where traditional practices have been lost. Such studies can thereby contribute with important knowledge to manage global pollinator loss.

Hedgerows, flowering strips, and natural areas that are adjacent to agricultural land have been shown to benefit crop production, via the provision of insect pollinators that pollinate crops. However, we do not yet know the extent to which bee habitat in the form of urban gardens might contribute to pollination services in surrounding crops. We explored whether gardens might provision pollinators to adjacent agricultural areas by sampling bees from gardens in the Portland, Oregon metropolitan area, and estimating typical foraging distances in the context of commercial-and residential-scale pollination-dependent crops up to 1000 m from garden study sites. We estimate that garden bees could forage outside of the garden in which they were collected, and that when pollination-dependent crops (commercial-scale or residential-scale) are nearby, 30–50% of the garden bee community could potentially provide pollination services to adjacent crops, if urban bees readily cross boundaries and forage among habitat types. Urban gardens might thus be well-positioned to provision neighboring farms and food gardens with pollination services, or could serve as a refuge for pollinators when forage is scarce or crop management practices are inhospitable. The actual capacity of gardens to serve as a refuge for pollinators from agricultural fields depends upon the extent to which bees forage across habitat types. However, relatively little is known about the degree to which bees move among habitat patches in heterogeneous landscapes. We thus propose a research agenda that can document the extent to which gardens contribute to pollinator health and pollination services at the interface of urban, peri-urban, and rural landscapes. In particular, more data is needed on how landscape context impedes or promotes garden bee movement between habitat types.

Commonwealth Human Ecology Council and Friends of the Earth report to the Commonwealth Heads of Government Meeting in Malta -CHOGM 2015
  Pollination is natural resilience at its best.
Action for bees and pollinators underpins Commonwealth concerns about resilience, food security, biodiversity and functioning natural ecosystems. The Commonwealth, its member nations and organisations can be at the forefront of action to reverse bee and pollinator decline. Bees and Pollinators: A Commonwealth Concern shows how the Commonwealth can start leading action to secure a vibrant, healthy future for our pollinators.
“The Commonwealth depends on these unsung pollinating heroes to help ensure plenty of good quality food is available, our economies prosper and our wildlife thrives.”
Professor Simon Potts, Co-Chair, ‘Pollinators,
Pollination and Food Production’ assessment
UN Intergovernmental Platform on Biodiversity
and Ecosystem Services (IPBES)

Planted meadows are increasingly used to improve the biodiversity and aesthetic amenity value of urban areas. Although many 'pollinator-friendly' seed mixes are available, the floral resources these provide to flower-visiting insects, and how these change through time, are largely unknown. Such data are necessary to compare the resources provided by alternative meadow seed mixes to each other and to other flowering habitats. We used quantitative surveys of over 2 million flowers to estimate the nectar and pollen resources offered by two exemplar commercial seed mixes (one annual, one perennial) and associated weeds grown as 300m 2 meadows across four UK cities, sampled at six time points between May and September 2013. Nectar sugar and pollen rewards per flower varied widely across 65 species surveyed, with native British weed species (including dandelion, Taraxacum agg.) contributing the top five nectar producers and two of the top ten pollen producers. Seed mix species yielding the highest rewards per flower included Leontodon hispidus, Centaurea cyanus and C. nigra for nectar, and Papaver rhoeas, Eschscholzia californica and Malva moschata for pollen. Perennial meadows produced up to 20x more nectar and up to 6x more pollen than annual meadows, which in turn produced far more than amenity grassland controls. Perennial meadows produced resources earlier in the year than annual meadows, but both seed mixes delivered very low resource levels early in the year and these were provided almost entirely by native weeds. Pollen volume per flower is well predicted statistically by floral morphology, and nectar sugar mass and pollen volume per unit area are correlated

Agri-environment schemes have been implemented across the European Union in order to reverse declines in farmland biodiversity. To assess the impact of these schemes for bumblebees, accurate measures of their populations are required. Here, we compared bumblebee population estimates on 16 farms using three commonly used techniques: standardised line transects, coloured pan traps and molecular estimates of nest abundance. There was no significant correlation between the estimates obtained by the three techniques, suggesting that each technique captured a different aspect of local bumblebee population size and distribution in the landscape. Bumblebee abundance as observed on the transects was positively influenced by the number of flowers present on the transect. The number of bumblebees caught in pan traps was positively influenced by the density of flowers surrounding the trapping location and negatively influenced by wider landscape heterogeneity. Molecular estimates of the number of nests of Bombus terrestrisand B. hortorumwere positively associated with the proportion of the landscape covered in oilseed rape and field beans. Both direct survey techniques are strongly affected by floral abundance immediately around the survey site, potentially leading to misleading results if attempting to infer overall abundance in an area or on a farm. In contrast, whilst the molecular method suffers from an inability to detect sister pairs at low sample sizes, it appears to be unaffected by the abundance of forage and thus is the preferred survey technique.

Agricultural intensification is a leading cause of global biodiversity loss, which can reduce the provisioning of ecosystem services in managed ecosystems. Organic farming and plant diversification are farm management schemes that may mitigate potential ecological harm by increasing species richness and boosting related ecosystem services to agroecosystems. What remains unclear is the extent to which farm management schemes affect biodiversity components other than species richness, and whether impacts differ across spatial scales and landscape contexts. Using a global metadataset, we quantified the effects of organic farming and plant diversification on abundance, local diversity (communities within fields), and regional diversity (communities across fields) of arthropod pollinators, predators, herbivores, and detritivores. Both organic farming and higher in-field plant diversity enhanced arthropod abundance, particularly for rare taxa. This resulted in increased richness but decreased evenness. While these responses were stronger at local relative to regional scales, richness and abundance increased at both scales, and richness on farms embedded in complex relative to simple landscapes. Overall, both organic farming and in-field plant diversification exerted the strongest effects on pollinators and predators, suggesting these management schemes can facilitate ecosystem service providers without augmenting herbivore (pest) populations. Our results suggest that organic farming and plant diversification promote diverse arthropod metacommunities that may provide temporal and spatial stability of ecosystem service provisioning. Conserving diverse plant and arthropod communities in farming systems therefore requires sustainable practices that operate both within fields and across landscapes.