POLLINATORS POLLINATION AND FOOD PRODUCTION

THE ASSESSMENT REPORT ON POLLINATORS, POLLINATION AND FOOD PRODUCTION
2015 US$ – Vanbergen et al., 2014). To facilitate further
discussion, Table 4.11 compiles all estimates of benefits on
a per-hectare scale for apple (Malus domestica), a widely
studied and grown fruit crop with high market value.
Table 4.11 illustrates that estimates still differ strongly
between countries and regions for the same crop e.g., the
benefits of pollination service to apples in China ($10,399/ha
– 2015 US$) are lower than in the USA (maximum $17,365/
ha 2015US$ – Calderone, 2012; Table 4.11). There are
also notable differences between benefits estimated with
different valuation methods for the same crop (Table 4.11)
– with replacement costs producing substantially smaller
estimates ($791-$1,634 2015 US$, Allsopp et al., 2008)
than most dependence ratio studies ($1,566-$21,744
2015 US$; Zych and Jakubiec, 2006; Calderone, 2012).
Even with these controls however, it is difficult to compare
the different methods as, although each is expressed in
monetary units, all methods measure fundamentally different
benefits (see Section 2). However, at both aggregate and
per hectare scales, it is apparent that the choice of method
can influence the magnitude of impacts that decisions are
based on, highlighting the need for transparent, clear and
comprehensive assessments of economic benefits in the
decision process.
7.4.2 Constraints and limits of current
economic valuations
Many studies give an economic valuation of pollinators and
pollination service and demonstrate the societal impacts a
change in pollinators could potentially have. However, most
of these valuation studies focus upon the contribution of
pollinators to agricultural production without directly linking
it with farmer decision-making. While a great number of
studies have illustrated the impacts of animal pollination
services on the agricultural sector, studies examining the
impacts of pollinator management on producer profits
(e.g., Ricketts et al., 2004) and marginal producer welfare
(e.g., Kasina et al., 2009) are relatively rare, limiting the
extent of decision support that can be provided by these
estimates. Various knowledge gaps also limit the capacity to
accurately transfer these benefit estimates to other regions.
Finally, most studies that have estimate the economic
value of pollination services (Southwick and Southwick,
1992; Gallai et al., 2009a; Winfree et al., 2011; Ritter,
2013 – Table 4.9) have almost exclusively focused on the
benefits to consumers rather than considering the potential
benefits to producers from rising prices (but see Bauer and
Wing, 2014).
Most studies focus on pollination services in their entirety –
assuming a complete loss of wild and managed pollinators.
While this demonstrates the benefits of pollinators as whole,
it can under- or over-state the contextual importance of
one group or the other, with several studies suggesting
that managed pollinators are perfect substitutes for wild
species (e.g., Winfree et al., 2011) or that wild species
are incapable of fully replacing managed pollinators (e.g.,
Southwick and Southwick, 1992). In reality Garibaldi et al.
(2013) demonstrates that in many systems, wild pollinators
cannot be perfectly substituted with managed honeybees
(the most widespread managed pollinator) and Rader et al.
(2009) illustrate the contextual importance of both groups.
Understanding and measuring the relative importance
of both groups to crop production would allow for more
targeted and effective management strategies.
Finally, as illustrated in the TEV diagram (Figure 4.1), the
benefit to society offered by pollination service is broader
than food production alone. The benefits of landscape
aesthetics, wild plant diversity and crop genetic resources
to present and future generation are also essential for
the maintenance of the social welfare. However, very few
studies have directly addressed this point, limiting the
perspective of benefits to just the most overtly consumable
(Mwebaze et al., 2010; Diffendorfer et al., 2014; Breeze et
al., 2015).
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4. ECONOMIC VALUATION OF POLLINATOR GAINS
AND LOSSES