Last updated: September 2014
Can the environmental and economic value of bees be quantified?
Apis mellifera, the only insect that produces food eaten by humans on a commercial scale, has become an icon for other insects to aspire to. Sadly, a failure to understand the importance of this and other species within our broader ecosystem has resulted in a number of apocalyptic realities. Markus Imhoof's documentary 'More than Honey' depicts one such scenario: a blossoming apple orchard in Liaoning province in Northeastern china, with hundreds of workers taking on the role of the absent bees to hand pollinate flowers.
Although this situation is not completely down to a lack of bees, but also the intensive monoculture of self-sterile fruit trees, it gives an insight into what the world could look like if bees were no longer around.
In Markus's new book 'More than Honey', published in 2015, he comments on the Liaoning scenario:
“Of all the people we met, we eventually settled on Zhang Zao in the northern province of Liaoning because she herself was the bee: as there are only five days of apple blossom in the north, there is not enough time to harvest the pollen, process it and get it to the blossom, so she travels 2,000 kilometers to the south where the apples blossom a month earlier. She gathers the pollen there and travels back north in time to pollinate the apple blossoms. Her story illustrates the immense efforts and costs involved if bees were to vanish”.
Bizarrely it is currently more economical to hand pollinate the apple orchards of Liaoning province rather than import bees or change the land use.
This unusual situation raises the questions: arebees really necessary? 'Which fertilises better. Man or bee?' And how can the ecosystem services offered by pollinating insects be quantified in order to raise their profile within decision making?
Are bees necessary?
Without hesitation, yes. By pollinating flowers and contributing to the process of successful and 'full' fertilisation, bees allow for the formation of high quality fruit and seeds. This helps to maintain both high yields, genetic diversity and contributes to maintaining high biodiversity. By supporting greater biodiversity, bees are directly linked to supporting resilient ecosystems that are better equipped to dealing with traumas such as changes in climate.
Bees also help to maintain our varied diets. A pollinator-dependant meal is typically more nutritionally diverse than if comprised solely of wind pollinated crops such as cereals. According to the UN, 100 crops make up 90 percent of the world’s food supply. 70 percent of these crops are pollinated by bees, the reliance of which will vary depending on the crop.
Crops pollinated by bees include almonds, apricots, apples, pears, rapeseed (also used for biofuels), and other important nonfood crops such as cotton.Bees are also far greater pollinators than humans will ever be. Although difficult to quantify and compare, a human can typically pollinate 5–10 trees a day depending on the size of the trees.
A colony of 50,000 bees can pollinate 500,000 flowers a day, and will make numerous visits to the same flower, ensuring full fertilisation and a heavier and healthier fruit. (For a strawberry to fully develop it needs about 21 visits from bees).
Due to the wide diversity of bee species, bees are able to pollinate a variety of flowers due to their multiple different shapes and sizes. Bees also show consistency in maintaining species-specific forages, ensuring more successful fertilisation.
The species of plant a bee forages from is determined and communicated by scout bees- a colony's forage experts who search for good pollen and nectar sources. The importance of a colony's social skills is perhaps not fully understood, but the knowledge bees gather about the location of good pollen sources and flower 'opening times' is known to contribute to efficient pollination. Humans generally lack this skill without access to technology.
The economic importance of bees
It is very difficult to identify and value all the ecosystem services offered by bees and other pollinators such as butterflies, moths, bats, flies, wasps and beetles. The UK National Ecosystem Assessment Analysis Report (2011), contains a chapter which discusses how biodiversity may be valued, and explores the benefits offered by pollinators:
“Roughly twenty percent of the UK cropped area comprises of pollinator dependent crops and a high proportion of wild flowering plants depend on insect pollination for reproduction. Pollinators offer an essential ecosystem service which maintains biodiversity and supports other vital ecosystem functions; including soil protection, flood control and carbon sequestration. There is strong evidence that loss of pollinators reduces crop yield and that the availability of a diverse pool of pollinators tends to lead to greater yields”.
A number of research groups have tried to quantify the economic importance of pollinators by valuing products, dependant on pollinators, that enter human supply chains. As a result, the majority of research has focused on honey bees due to their dual importance – their honey and pollination services. Little research has focused on the economic importance of the UK’s other 266 wild bee species (or the 25,000-30,000 other bee species globally) that are important pollinators but don’t produce honey for humans.
In 2009 the National Audit Office valued honeybee pollination services for the UK at just under £200 million a year, with the retail value of products pollinated by honey bees being valued at closer to £1bn.
This audit considered oil seed rape (used for vegetable oil and bio-fuels), field bean, broad beans, runner beans, apples, pears, strawberries, raspberries and other soft and orchard fruit in its assessment. A later study by the University of Reading for Friends of the Earth’s Bee Cause campaign calculated that if humans were to pollinate these same crops by hand instead of bees, it would cost UK farmers at least £1.8bn a year.
If pollinator populations were to be wiped out, a predicted 4%- 6% decrease in global agricultural production (by mass) would be observed.
However, pollinatordependant crops tend to be of a higher economic value than non-dependant crops. This relatively small decline would therefore have greater economic implications than a similar decline in wind-pollinated crops. On a global level, the value of pollinator services are predicted to be around £130 billion per year (approximately 10% of the economic value of agricultural production).
This prediction does not account for the effect changes in food prices would have on the willingness of consumers to pay more for their food and commodities. (The value of fruit and vegetables dependant on pollinators would in theory increase if pollinator populations were to significantly decline).
The financial loss that this may entail, is predicted to be between £160 to £260 billion. If this value was to be added to £130 billion (the global value of pollinator services), the total global value of pollinators could be approximated at £290-£390 billion, 25%-30% of the economic value of agricultural production.
These studies demonstrate the two main approaches currently utilised by researchers trying to place an economic value on bees. The 'deficit model' tries to calculate the cost incurred by the reduced quality and yield of crops associated with declining pollinator populations. The 'compensation model' tries to calculate the costs incurred by mitigating against pollinator declines – by planting wild flower meadows or hand pollinating flowers. Although a step in the right direction, certain factors are not accounted for or incorporated into these models.
- Pollinator declines will have varying economic impacts depending on the dependence of a country or region on agriculture or, more specifically, pollinator dependant crops.
- More and more land is being used to grow pollinator- dependant crops. This demand is out-stripping by 4.9 times the number and variety of bee species needed to pollinate them.
- With a decrease in crop yield and quality, product prices will theoretically increase and result in consumer's being less willing to buy pollinator-dependant crops regularly.
- The impact of pollinator declines on nutrition and the associated health implications and costs are not taken into consideration
- The impact of pollinator declines on seed quality are not taken into consideration
At present, observed pollinator population declines do not seem to be having an obvious economic impact. When a range of pollinator-sensitive sectors (agro-chemical, food producers and
retailers, luxury good and beverages) were interviewed by Rick Stather's, Schroder's head of Responsible Investment, about the impact of pollinator declines on their businesses, all generally agreed with Marks and Spencer's in saying 'there clearly was a cost but its value would only be recognised when the service was completely lost'.
However, the commonly quoted £130 billion a year figure is large enough to suggest the huge and unknown importance of pollinating insects for both humanity and our earth's terrestrial ecosystems, and will hopefully help focus the minds of economists, politicians and businesses on this issue.