Impact of landscape configuration and composition on pollinator communities across different European biogeographic regions

IntroductionHeterogeneity in composition and spatial configuration of landscape elements support diversity and abundance of flower-visiting insects, but this is likely dependent on taxonomic group, spatial scale, weather and climatic conditions, and is particularly impacted by agricultural intensification. Here, we analyzed the impacts of both aspects of landscape heterogeneity and the role of climatic and weather conditions on pollinating insect communities in two economically important mass-flowering crops across Europe. MethodsUsing a standardized approach, we collected data on the abundance of five insect groups (honey bees, bumble bees, other bees, hover flies and butterflies) in eight oilseed rape and eight apple orchard sites (in crops and adjacent crop margins), across eight European countries (128 sites in total) encompassing four biogeographic regions, and quantified habitat heterogeneity by calculating relevant landscape metrics for composition (proportion and diversity of land-use types) and configuration (the aggregation and isolation of land-use patches). ResultsWe found that flower-visiting insects responded to landscape and climate parameters in taxon- and crop-specific ways. For example, landscape diversity was positively correlated with honey bee and solitary bee abundance in oilseed rape fields, and hover fly abundance in apple orchards. In apple sites, the total abundance of all pollinators, and particularly bumble bees and solitary bees, decreased with an increasing proportion of orchards in the surrounding landscape. In oilseed rape sites, less-intensively managed habitats (i.e., woodland, grassland, meadows, and hedgerows) positively influenced all pollinators, particularly bumble bees and butterflies. Additionally, our data showed that daily and annual temperature, as well as annual precipitation and precipitation seasonality, affects the abundance of flower-visiting insects, although, again, these impacts appeared to be taxon- or crop-specific. DiscussionThus, in the context of global change, our findings emphasize the importance of understanding the role of taxon-specific responses to both changes in land use and climate, to ensure continued delivery of pollination services to pollinator-dependent crops

Impact of landscape configuration and composition on pollinator communities across different European biogeographic regions

Introduction: Heterogeneity in composition and spatial configuration of landscape elements support diversity and abundance of flower-visiting insects, but this is likely dependent on taxonomic group, spatial scale, weather and climatic conditions, and is particularly impacted by agricultural intensification. Here, we analyzed the impacts of both aspects of landscape heterogeneity and the role of climatic and weather conditions on pollinating insect communities in two economically important mass-flowering crops across Europe. Methods: Using a standardized approach, we collected data on the abundance of five insect groups (honey bees, bumble bees, other bees, hover flies and butterflies) in eight oilseed rape and eight apple orchard sites (in crops and adjacent crop margins), across eight European countries (128 sites in total) encompassing four biogeographic regions, and quantified habitat heterogeneity by calculating relevant landscape metrics for composition (proportion and diversity of land-use types) and configuration (the aggregation and isolation of land-use patches). Results: We found that flower-visiting insects responded to landscape and climate parameters in taxon- and crop-specific ways. For example, landscape diversity was positively correlated with honey bee and solitary bee abundance in oilseed rape fields, and hover fly abundance in apple orchards. In apple sites, the total abundance of all pollinators, and particularly bumble bees and solitary bees, decreased with an increasing proportion of orchards in the surrounding landscape. In oilseed rape sites, less-intensively managed habitats (i.e., woodland, grassland, meadows, and hedgerows) positively influenced all pollinators, particularly bumble bees and butterflies. Additionally, our data showed that daily and annual temperature, as well as annual precipitation and precipitation seasonality, affects the abundance of flower-visiting insects, although, again, these impacts appeared to be taxon- or crop-specific. Discussion: Thus, in the context of global change, our findings emphasize the importance of understanding the role of taxon-specific responses to both changes in land use and climate, to ensure continued delivery of pollination services to pollinator-dependent crops

Calidad nutricional del polen y efecto de la alimentación complementaria sobre poblaciones de abeja "Apis mellifera iberiensis"

El cambio climático está afectando todos los ecosistemas del Planeta. Algunas de las evidencias del cambio son las temperaturas elevadas, sequías frecuentes y prolongadas, lluvias irregulares, etc. Estos factores afectan a los seres vivos, como las plantas y los insectos polinizadores, de diversas formas. La abeja doméstica es uno de los insectos polinizadores de mayor importancia económica y ecológica que está siendo afectada de manera directa e indirecta por los factores causantes del cambio climático. Las abejas dependen del néctar y polen que producen las plantas, por tanto, cuando las plantas son afectadas por los factores climáticos, las abejas padecen estrés nutricional. Debido que las abejas dependen del polen que consumen es necesario analizar su contenido nutricional para identificar la deficiencia de nutrientes. La colza (Brassica napus) y el manzano (Malus domestica) son dos de los monocultivos que la abeja doméstica (Apis mellifera) poliniza, y de las cuales obtiene néctar y polen. Por otro lado, la variación de los nutrientes del polen puede influir en el comportamiento productivo y reproductivo de la colmena. Aunado a lo anterior, los microsporidios como la Nosema sp y parásitos como el ácaro Varroa sp contribuyen a disminuir el tiempo de vida de las abejas y a un desarrollo adecuado de las larvas. Por último, en la última década se ha evidenciado de que hay una relación estrecha y positiva entre los componentes del sistema inmune de los insectos y la existencia de una flora intestinal de microorganismos específica, la microbiota. Por todo lo expuesto, se planteó; 1) evaluar el contenido de nutrientes de los monocultivos B. napus y M. domestica ubicados en Albacete y Murcia, respectivamente, 2) evaluar el contenido de nutrientes de polen en el colmenar de la Universidad Murcia durante un ciclo apícola, 3) evaluar el efecto de diferentes dietas con diferentes niveles de proteína sobre parámetros fisiológicos de abejas recién nacidas y, 4) evaluar el efecto de diferentes dietas a las que se han añadido estirpes bacterianas para que actúen como probióticos en los colmenares ubicados en Murcia y Soria. Se observó que los cultivos B. napus y M. domestica producen polen deficiente en grasa y en proteína. De los aminoácidos analizados se observó que Trp y Met se hallan en cantidades inferiores a las requeridas por las abejas, en tanto que entre los minerales resultaron deficientes el Mn, el Cu y el Zn. Durante un ciclo anual, todos los parámetros evaluados se incrementaron durante la primavera, disminuyeron durante el verano y se incrementaron nuevamente durante el otoño. La cantidad de polen y el porcentaje de proteína influyen de manera positiva sobre el número de larvas operculadas. La temperatura ambiental influye en la cantidad de polen colectado, en tanto que la precipitación lo hace sobre el porcentaje de humedad. Por último, se encontró un incremento en el consumo de alimento conforme avanza la edad de las abejas y en el peso corporal. Los niveles de proteína no afectan el contenido de grasa corporal pero sí a la edad, lo que sugiere que las abejas pueden ajustar su nivel de grasa conforme avanza su edad. La edad del insecto guarda una estrecha relación con la actividad fenoloxidasa, en especial a los días 6 y 9 días de edad. Además, estos parámetros tienen relación con los niveles de proteína, en especial al suministrar las dietas con contenido de proteína del 9% y el 12%. El número de esporas de Nosema sp fue superior en las colmenas de Murcia, particularmente en las colmenas suplementadas con las dietas 2 y 4, ambas dietas bajo restricción de patente. Sin embargo, la infestación disminuyó con el tiempo.Climate change is affecting all ecosystems on the planet. Some evidence of this change is high temperatures, frequent and prolonged droughts, irregular rainfall, etc. In various ways, these factors affect species, such as plants and pollinating insects. The domestic bee is one of the most economically and ecologically critical pollinating insects that is being directly and indirectly affected by the factors that cause climate change. Bees depend on the nectar and pollen produced by plants. Therefore, when plants are affected by climatic factors, bees suffer nutritional stress. Since bees depend on the pollen they consume, it is necessary to analyze its nutritional content to identify nutrient deficiencies. Rapeseed (Brassica napus) and apple (Malus domestica) are two of the monocultures that the domestic bee (Apis mellifera) pollinates and from which they obtain nectar and pollen. Furthermore, the variation of pollen nutrients can influence the productive and reproductive behavior of the hive. Moreover, microsporidia such as Nosema sp and parasites such as the Varroa sp mite contribute to reducing the lifespan of bees and adequate development of larvae. Finally, in the last decade, it has been shown that there is a close and positive relationship between the components of the immune system of insects and the existence of a specific intestinal flora of microorganisms, the microbiota. Thus, the main objectives of this thesis were: 1) to evaluate the nutrient content of monocultures B. napus and M. domestica located in Albacete and Murcia (Spain), respectively; 2) to evaluate the nutrient content of pollen in the Murcia University (Spain), apiary during a beekeeping cycle; 3) to evaluate the effect of different diets with different levels of protein on physiological parameters of newborn bees, and 4) evaluate the effect of different diets to which bacterial strains have been added to act as probiotics in apiaries located in Murcia and Soria (Spain). Cultures B. napus and M. domestica were found to produce pollen deficient in fat and protein. Of the amino acids analyzed, it was observed that Trp and Met are found in amounts lower than those required by bees, while Mn, Cu, and Zn were the most deficient minerals. During an annual cycle, all the parameters evaluated increased during the spring, decreased during the summer, and increased again during the autumn. The amount of pollen and the percentage of protein positively influence the number of operculated larvae. The environmental temperature influences the amount of pollen collected, while the precipitation influences the percentage of humidity. Finally, food consumption increased as the age of the bees and body weight increased. Protein levels do not affect body fat content, but age suggests that bees may adjust their fat levels as they age. The insect's age is closely related to phenoloxidase activity, especially at six and nine days of age. In addition, these parameters are related to protein levels, especially when fed with diets with 9% and 12% protein content. The number of Nosema sp spores was higher in Murcia (Spain) hives supplemented with diets 2 and 4, both under patent restrictions. However, the infestation decreased with tim