Authors: Valeria Leoni, Luca Giupponi, Sara Panseri and Anna Giorgi
Acknowledgement: UNIMONT – Università degli Studi di Milano
Mountain wildflower honey is a “picture” of the natural flora of the mountains, an excellence from meadows and pastures of our Alps, habitats protected by the European directives. Beekeeping in environments where spring and summer are short is tougher, inside a general trend of decline of pollinators. The habitat of many Alpine floral species is decreasing due to rising temperatures and many plants have a range more limited, with the alpine biome in general reduction.
In addition, mountain areas are fragile territories subject to climate change and socio-economic change. In the last decades, and still today, mountain areas are suffering a progressive depopulation. This human process has caused the abandonment of agricultural practices such as haymaking and grazing, and the expansion of forests in areas once occupied by mountain meadows and prairies, reducing the habitat for wild and domestic bees, and consequently the possibility of producing wildflower honey. For this reason, mountain wildflower honey is considered a Slow Food Presidia.
A product to study and characterise
The commercial definition of honey, or else its botanical origin, is very often defined through tasting or even simply considering the predominant flora surrounding the hive, without performing formal analysis Since some studies have suggested possible correlations between the floral origin, the profile of flavonoids, and the presence of volatile substances derived from nectar in honey aroma, a detailed phytochemical characterization could provide additional information on honey features. The chemical composition and the consequent properties of honey depend largely on its floral source which is very dependent on the geographical origin of honey.
The knowledge of the botanical origin of honey could give important cues also for beekeeping management, since there are certain key species or plant groups that are particularly important. Apparently, honeybees appear to prefer some flowers, as some Ericacee or Rubus shrubs and some broad-leaved trees as sweet chestnut or Tilia species. A valuable area of further research is to discover why these species are important and how flora composition affect bee foraging in different environments. For example, apparently chestnut nectar could contain substances attractive for bees, as kynurenic acid, that appears involved in the regulation of the stress-related hormone dopamine in the honeybee as well as in other animal species. Other plant species produce alkaloids as nicotine, which effects on honeybees and other pollinator behaviours are being deeply investigates. Hence, plant-insect communication is a fascinating field to explore also in the husbandry field of beekeeping.
Strict connection to bee behaviour
Apparently, also the pattern of the vegetation and the landscape affect honeybees foraging behaviour. It was seen how honeybees from the same colony forage across areas spanning up to several hundred square kilometres, and at linear distances as far as 9 km from the hive, or even 12 km when starving. “Onlooker” bees find nectar sources and among them there is a difference between the bees that “scout” for different nectar sources or “recruit” for well-known floral resources, and there is an optimal ratio of “scouters” and “recruiters”, for the most successful cooperative foraging for the beehive survival. This ratio appears linked to biology and genetics, but also to the structure of the landscape in which the bees look for food: different studies suggest that when resources are concentrated into a small number of highly rewarding patches, colonies perform best with few scouters and many recruiters, while when resource patches are small, evenly distributed, and easy to locate, successful colonies invest more in scouting than in recruitment. This is strictly linked to climate and social changes in the mountains: mountain grasslands are no longer evenly distributed and easily localizable, as they are scattered among expanding areas of shrublands and forests and, for the above-mentioned reasons, it is more efficient for the colony to invest in more recruiters than scouters, as recruiters will identify a small number of highly rewarding patches, such as raspberry or rhododendron shrublands or linden and chestnut woods, that are highly rewarding and very different in quality, so they can be easily “recruited” by foraging bees.
The challenging activity of beekeeping in high mountain
Considering all the evaluations above, to produce mountain wildflower honey is becoming more and more difficult for beekeepers. When transhumance was widespread and regular in the Alps, bees (wild and domesticated) also benefited: the pastures were cared for and cleaned to the benefit not only of the animals, but also of the vegetation, and then the bees. Even if hives are positioned in grasslands rich in Alpine herbaceous species, nowadays beekeepers often obtain honey from the upper (as rhododendron honey) or lower botanical fascia (as sweet chestnut or linden honey) instead of mountain wildflower honey.
Yet, there is a reverse side of the coin: the poorly connected mountain territories, with few roads and little inhabitants, are also little polluted environments that guarantee scarce but high-quality and uncontaminated productions, other than being a pristine habitat also for other pollinators. It is well known, in fact, that bees (and their products) are effective environment sentinels. Further, honey, like many other bee products like propolis, could be interesting as well for herbal medicine and cosmetics, and the production of honey in uncontaminated mountain areas can be a way of promoting this product so difficult to obtain, together with the promotion of bioactive properties of a sustainable product from marginal territories.
Reference
Leoni, V., Giupponi, L., Pavlovic, R. et al. Multidisciplinary analysis of Italian Alpine wildflower honey reveals criticalities, diversity and value. Sci Rep 11, 19316 (2021). https://doi.org/10.1038/s41598-021-98876-y