Filipiak Michał, Kuszewska Karolina, Asselman Michel, Denisow Bożena, Stawiarz Ernest, Woyciechowski Michał, Weiner January
Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland.
Department of Botany, Laboratory of Horticultural Plant Biology, University of Life Sciences in Lublin, Lublin, Poland.
PLoS One. 2017 Aug 22;12(8):e0183236. doi: 10.1371/journal.pone.0183236. eCollection 2017.
The least understood aspects of the nutritional needs of bees are the elemental composition of pollen and the bees' need for a stoichiometrically balanced diet containing the required proportions of nutrients. Reduced plant diversity has been proposed as an indirect factor responsible for the pollinator crisis. We suggest stoichiometric mismatch resulting from a nutritionally unbalanced diet as a potential direct factor. The concentrations and stoichiometric ratios of C, N, S, P, K, Na, Ca, Mg, Fe, Zn, Mn, and Cu were studied in the bodies of honeybees of various castes and sexes and in the nectar and pollen of various plant species. A literature review of the elemental composition of pollen was performed. We identified possible co-limitations of bee growth and development resulting mainly from the scarcity of Na, S, Cu, P and K, and possibly Zn and N, in pollen. Particular castes and sexes face specific limitations. Concentrations of potentially limiting elements in pollen revealed high taxonomic diversity. High floral diversity may be necessary to maintain populations of pollen eaters. Single-species crop plantations, even if these species are rich in nectar and pollen, might limit bee growth and development, not allowing for gathering nutrients in adequate proportions. However, particular plant species may play greater roles than others in balancing honeybee diets. Therefore, we suggest specific plant species that may (1) ensure optimal growth and production of individuals by producing pollen that is exceptionally well balanced stoichiometrically (e.g., clover) or (2) prevent growth and development of honeybees by producing pollen that is extremely unbalanced for bees (e.g., sunflower). Since pollen is generally poor in Na, this element must be supplemented using "dirty water". Nectar cannot supplement the diet with limiting elements. Stoichiometric mismatch should be considered in intervention strategies aimed at improving the nutritional base for bees.
蜜蜂营养需求中最不为人所理解的方面，是花粉的元素组成以及蜜蜂对含有所需营养比例的化学计量平衡饮食的需求。植物多样性降低被认为是导致传粉者危机的一个间接因素。我们认为，营养不均衡饮食导致的化学计量不匹配是一个潜在的直接因素。研究了不同蜂种和性别的蜜蜂体内以及不同植物物种的花蜜和花粉中碳、氮、硫、磷、钾、钠、钙、镁、铁、锌、锰和铜的浓度及化学计量比。对花粉的元素组成进行了文献综述。我们确定了蜜蜂生长和发育可能存在的共同限制因素，主要是花粉中钠、硫、铜、磷和钾的稀缺，可能还有锌和氮的稀缺。特定的蜂种和性别面临着特定的限制。花粉中潜在限制元素的浓度显示出高度的分类多样性。保持食花粉者的种群数量可能需要高度的花卉多样性。单一作物种植园，即使这些作物富含花蜜和花粉，也可能限制蜜蜂的生长和发育，无法让蜜蜂获取足够比例的营养。然而，特定的植物物种可能在平衡蜜蜂饮食方面比其他物种发挥更大的作用。因此，我们提出了一些特定的植物物种，它们可能（1）通过产生化学计量极其平衡的花粉（如三叶草）来确保个体的最佳生长和繁殖，或者（2）通过产生对蜜蜂来说极其不平衡的花粉（如向日葵）来抑制蜜蜂的生长和发育。由于花粉中钠通常含量较低，必须用“脏水”来补充这种元素。花蜜无法为饮食补充限制元素。在旨在改善蜜蜂营养基础的干预策略中，应考虑化学计量不匹配的问题。
