Changing Climate, Rising Temperature Can Cause Decline In Bees' Honey Production, Study Finds

Certain factors have been affecting the honey production among bees.

A recent study disclosed that these circumstances include climate change, rising temperatures, altered rainfall patterns, extreme weather events, and even the conversion of previously flower-rich land into monocultural farmland.

Anthropogenic Stressors

Researchers noted that pollinators are an essential component of terrestrial food webs and agricultural systems but at present, they are threatened by insufficient access to floral resources.

Managed honey bees, as generalist foragers that hoard nectar as honey, can act as bioindicators of floral resources available to pollinators in a given landscape through their accumulation of honey.

Experts pointed out that honey yields across the United States have decreased appreciably since the 1990s, concurrent with shifts in climate, land-use, and large-scale pesticide application.

They said that while many factors can affect honey accumulation, results of the study suggested that anthropogenic stressors may be having large-scale impacts on the floral resources that pollinators depend on for their nutrition.

Lead authors of the study had used hierarchical partitioning on five decades of state-level data to parse the most important environmental factors and likely mechanisms associated with spatial and temporal variation in honey yields across the US.

Data on average honey yield per colony, land use, herbicide use, climate, weather anomalies, and soil productivity in the continental United States were obtained from multiple open-source repositories and varied in their temporal extent, temporal resolution, and spatial resolution.

They emphasized that climatic conditions and soil productivity were among the most important variables for estimating honey yields, with states in warm or cool regions with productive soils having the highest honey yields per colony.

These findings indicated that foundational factors constrain pollinator habitat suitability and define ecoregions of low or high honey production.

The most important temporally varying factors were change in herbicide use or land use, such as the increase in intensive agriculture and reduction in land conservation programs that support pollinators and annual weather anomalies.

It was found out that honey yield per colony were generally increasing from the middle portion of the 1970's to early 1990's but it decreased precipitously since the early 1990's.

However, general patterns in regional productivity have remained consistent across time, with states in the Northern Great Plains and along the Gulf Coast consistently producing the greatest honey yields per colony across years.

In both periods, scientists said that sources of spatial variation across states (climate, soil productivity, proportion of soybean or conservation land, and herbicide use) were much more important than sources of temporal variation in each state (weather anomalies, changes proportion of soybean or conservation land, changes in herbicide use).

The study provided insights into the interplay between broad abiotic conditions and fine temporal variation on habitat suitability for honey bees and other pollinators.

''We suggest that climate and soil productivity underpin floral regions by constraining the available plant communities, while land use and weather modulate the realized floral resources and annual productivity of that community,'' the study indicated.

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Controlling Undesirable Vegetation

Herbicides are said to be among the factors in the decline of honey production.

The United States Environmental Protection Agency defined herbicides as the chemicals used to manipulate or control undesirable vegetation.

Herbicide application occurs most frequently in row-crop farming, where they are applied before or during planting to maximize crop productivity by minimizing other vegetation.

Experts said that these may also be applied to crops in the fall, to improve harvesting.

Related Article: Pesticide Mixtures Disrupt Honey Bee Communication and Colony Function