POLLINATORS POLLINATION AND FOOD PRODUCTION

THE ASSESSMENT REPORT ON POLLINATORS, POLLINATION AND FOOD PRODUCTION
magnitude of impacts and the probability of them
occurring (ISO, 2009). Economic theory usually assumes
that people are either risk-averse (avoid risks), risk-neutral
(indifferent to risk) or risk-loving (seeking risk) in different
situations. Economic analyses often assume that agents
are risk-averse and will therefore typically make decisions
that have lower risks than other decisions (i.e., are either
less likely to occur and are less likely to be negative)
than other decisions. Changes to pollinator populations
can increase the risk of inadequate pollination service
delivery if key species decline. Managed pollinators can
reduce these risks but over-reliance can impose other
risks to growers should production costs rise (Rucker
et al., 2012). By increasing the flow of genetic materials
within plant populations, pollination can also increase
resistance to disease, reducing the risks of yield loss from
disease outbreaks. For example, Mexican production
of bat pollinated Agave cacti, farmed as the basis for
tequila production, has suffered substantial losses from
outbreaks of vascular wilt (Fusarium oxysporum) due to a
reliance upon cloned varieties with little resistance to the
fungus (Ávila-Miranda et al., 2010).
• Vulnerability measures the degree to which a system
is susceptible to and is unable to cope with adverse
effects (McCarthy et al., 2001). Vulnerability is a function
of three elements: exposure, sensitivity and adaptive
capacity (Turner et al., 2003). In the case of pollination,
the exposure can be represented by the dependency
of a plant upon pollination to reproduce or, for crops,
the change in crop yields or economic outputs affected
by changes in pollinator populations. The sensitivity
is indicated by the shape of the relationship between
pollination and benefit (linear, concave or convex yield
loss). The adaptive capacity of the cropping system
can be approximated by the capacity of alternative
techniques to substitute animal pollinators (e.g.,
substituting managed pollinators for wild species or
increasing other inputs).
• Resilience (in the context of social-ecological systems 3 )
refers to the capacity of a system to return to its original
state after being disturbed and the magnitude of change
it can sustain before it changes to a radically different
state (e.g., Berkes et al., 2003; Folke, 2006). In the case
of pollinator communities, resilient communities are those
that can continue to provide a reliable level or services
even in the case of temporary or permanent loss of
major pollinators. Communities that are more resilient
will recover from temporary declines in key species (e.g.,
temporary population declines due to extreme weather)
than less resilient communities (which may permanently
cease to provide any services).
3. The concept of resilience has also been used for many decades in
material sciences or in psychology.
4.2 Incorporating stability into
standard valuation methods
Although variation in pollination services can result in
uncertain benefits (e.g., Bauer and Wing, 2014), to date,
most valuation studies have not considered issues of
service variability within the benefits of pollination services
(Melathopoulos et al., 2015), often only providing a single
estimate of benefits rather than a range of possible values
(see Section 7). Uncertainty has been incorporated into
some existing dependence ratio and surplus analysis studies
by assessing the impacts that variations in certain factors,
such as dependence ratios (Lautenbach et al., 2012), price
elasticities (Gallai et al., 2009a) or substitution parameters
(Bauer and Wing, 2014) can have on estimates of value. In
yield analysis, uncertainty can be incorporated by estimating
value subject to inter-site or inter-annual variance in the
benefits observed. The production function method can
directly capture the effects of variation in several aspects of
pollinator communities on service delivery, identifying how
community variations may cause the output to vary.
Risks from potential honeybee losses have been
incorporated into some dependence ratio (Section 2.2.)
and surplus analysis (Section 2.4) studies (e.g., Cook et al.,
2007; Southwick and Southwick, 1992) using hypothetical
or expert derived weights that reflect the capacity of wild
pollinators to replace honeybee losses. In these studies, the
risk value of honeybee loss is the value of production that
cannot be compensated for by other pollinators. However,
these weights are subject to many of the assumptions of
dependence ratios themselves and often stem from the
assumption that honeybees are presently the majority
pollinator, which may not be the case (Garibaldi et al., 2013).
Within stated preference studies, risk can be applied to
non-market benefits by including an attribute representing
the probability that the benefits will not be delivered as
described. Vulnerability of producer benefits can be
quantified by estimating the proportion of the total economic
value of the agricultural sector (Gallai et al., 2009a) or
agricultural GDP lost in the event of pollinator community
collapse (e.g., Lautenbach et al., 2012).
4.3 Additional methods for
assessing the economic value of
stability
A number of methods from the wider ecological economics
literature are also suitable to specifically assess the
economic value of stability and resilience in benefits from
pollinators, the most relevant of which are reviewed below.
These values are generally considered distinct from the
direct use value of service benefits themselves but can draw
upon methods to estimate use values, becoming an additive
factor in assessing TEV by quantifying the uncertainty
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4. ECONOMIC VALUATION OF POLLINATOR GAINS
AND LOSSES