Data from: Honeybee nutrition is linked to landscape composition

Declines in insect pollinators in Europe have been linked to changes in land use. Pollinator nutrition is dependent on floral resources (i.e., nectar and pollen), which are linked to landscape composition. Here, we present a stratified analysis of the nutritional composition of beebread in managed honeybee hives with a view to examining potential sources of variation in its nutritional composition. Specifically, we tested the hypothesis that beebread composition correlates with local land use and therefore available floral resources. The results demonstrated that the starch, lipid, and moisture contents of beebread are all highly conserved across hives, whereas levels of protein and nonreducing sugar increased as the year progressed, reducing sugars, however, decreased during the first half of the year and then increased toward the end. Local land use around hives was quantified using data from the Countryside Survey 2007 Land Cover Map. Bee-bread protein content was negatively correlated with increasing levels of arable and horticultural farmland surrounding hives and positively correlated with the cover of natural grasslands and broadleaf woodlands. Reducing sugar content was also positively correlated with the amount of broad-leaved woodland in a 3 Km² radius from the hives. Previous studies on a range of invertebrates, including honeybees, indicate that dietary protein intake may have a major impact on correlates of fitness, including longevity and immune function. The finding that beebread protein content correlates with land use suggests that landscape composition may impact on insect pollinator well-being and provides a link between landscape and the nutritional ecology of socially foraging insects in a way not previously considered.

欧洲的昆虫传粉者（insect pollinators）种群衰退与土地利用变化存在关联。传粉者的营养需求依赖于花源资源（floral resources）——即花蜜与花粉，这类资源与景观组成紧密相关。本研究针对人工饲养的蜜蜂蜂箱中的蜂粮（beebread）营养组成开展分层分析，旨在探究其营养组成的潜在变异来源。具体而言，我们验证了如下假说：蜂粮组成与当地土地利用情况及由此可得的可利用花源资源相关联。

研究结果显示，不同蜂箱的蜂粮中淀粉、脂质与水分含量均保持高度保守；蛋白质与非还原糖含量随年度推进逐渐升高，而还原糖则在上半年呈下降趋势，年末又有所回升。

我们采用《2007年乡村调查土地覆盖图》（Countryside Survey 2007 Land Cover Map）的数据，对蜂箱周边的当地土地利用情况进行量化分析。结果表明，蜂粮的蛋白质含量与蜂箱周边耕地及园艺农田的占比呈负相关，与天然草原和阔叶林地的覆盖面积呈正相关。还原糖含量同样与蜂箱周边3平方公里半径范围内的阔叶林地面积呈正相关。

此前针对包括蜜蜂在内的多种无脊椎动物的研究表明，膳食蛋白质摄入可能对昆虫适合度的相关指标——包括寿命与免疫功能——产生重大影响。本次研究发现蜂粮蛋白质含量与土地利用情况相关，这提示景观构成可能会影响昆虫传粉者的健康状况，并揭示了景观与社会性觅食昆虫营养生态学之间此前未被关注的关联。