POLLINATORS POLLINATION AND FOOD PRODUCTION

THE ASSESSMENT REPORT ON POLLINATORS, POLLINATION AND FOOD PRODUCTION
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3. THE STATUS AND TRENDS IN POLLINATORS
AND POLLINATION
for nesting in Bhutan, Nepal and India (Verma, 1991; Pain,
2009; Vit, 2013). In parts of Indonesia local communities
have devised innovative ways of enticing migratory swarms
of A. dorsata using rafters placed in strategic locations for
these bees to construct combs, and carefully manage these
in relation to flowering trees in the forest, but see an overall
decline due to the loss of forest cover to oil-palm plantations
(Madhu Duniya, 2011, Césard and Heri, 2015). In both
wild stingless bee and honey bee colonies (all Apis spp.)
there is a need for more thorough baseline assessments to
establish whether declines are on-going, are reversible and
what the drivers of these are (see Chapters 2 and 6). This
is also an opportunity for inter-disciplinary collaborations
between scientists as well as holders of indigenous and
local knowledge.
3.10 Knowledge gaps and
recommendations
An obvious conclusion of our survey of the state of
knowledge of status and trends in pollinators is that
surprisingly little is known about them, with the exception
of honey bees (Apis mellifera) and some bumble bees
(Bombus species) and for a few well-studied regions of the
world, particularly NW-Europe and North America. Given
that these are only a tiny fraction of the diversity of pollinator
species on the planet, it is difficult to draw conclusions,
other than broad generalizations, with much confidence.
Although the growing interest in pollinators and research
on them and the ecosystem services they provide allow
us to go somewhat beyond the similar conclusions of a
study of the status of North American pollinators (National
Research Council, 2007), it is obvious that much remains
to be learned. For an overview of key questions in this field
also see Mayer et al. (2011), who list questions drawn up by
the scientific experts in the field. Note, however, that they list
mainly scientific questions. These questions alone can rarely
provide a complete answer to questions involving societal
stakeholders such as farmers or (traditional) managers of
bees or natural areas (see Biesmeijer et al., 2011).
To assess better the status of pollinators,
standardized pollinator monitoring schemes need
to be implemented. Monitoring of honey bees (recently
set-up as part of the CoLoSS network and now broadly
adopted) now annually provides precise estimates of
winter colony mortality for many countries. This provides
policy-makers with essential information to design
mitigation strategies. Monitoring of other pollinator groups,
particularly bees and flies that dominate pollination in
many ecosystems, is more difficult, but not impossible.
Only in this way can policies be targeted to those groups
and regions where acute problems actually are occurring.
Monitoring should target both natural ecosystems (where
many threatened pollinators and pollinator-dependent plants
occur) and agro-ecosystems (where pollinators are needed
for crop pollination). Note that some pollinator groups are
severely understudied, e.g., beetles, wasps, and moths (see
Cascante et al., 2002; Donaldson et al., 2002; Johnson et
al., 2004).
Occurrence of pollination deficits for crops and wild
plants and its cascading effects are largely unknown.
More studies are needed to (1) assess in which crops
and under which management and landscape conditions
pollination deficits occur; (2) identify when and where in
natural systems wild plants suffer from pollination deficits;
(3) whether pollination deficits lead to yield gaps (in
crops), lower reproduction and population decline (in wild
plants). Monitoring for pollination deficits would produce
important information on status and (after some years)
trends on which policy-makers could base incentives and
mitigation measures.
Our knowledge of plant-pollinator networks is often
too limited to predict impact of climate change
and other drivers on interaction networks and their
ecosystems. Currently information is mostly collected on
visitation (e.g., hummingbird A visits flower X), whereas
pollination (e.g., hummingbird A deposits 125 pollen grains
per visit to flower X) or reward intake (e.g., hummingbird
A collects 1mg of sugar per visit to flower X) are the
ecologically relevant parameters. Such information is
particularly relevant in light of the “rewiring” that takes place
in flower visitation webs as species composition changes in
response to disturbances, or over time.
Scientific knowledge, albeit incomplete, does not
always reach farmers, habitat managers or policymakers.
Scientists need to be more active in making their
knowledge accessible. Awareness of policy-makers, farmers
and the general public can only increase when information
on pollination is included in the right way and through the
channels used by each stakeholder group. For example,
inclusion of pollination information and promotion of best
pollination practices in agricultural extension could improve
crop yields and pollinator-friendly crop management.
Traditional and local knowledge on pollinators, their
products and pollination practices is underused
in policy and science. Such information needs to be
collected before it disappears and can be important in
guiding communities towards sustainable futures. For
example, knowledge on traditional management of stingless
bees in many tropical regions may be applied in crop
pollination and small-scale farming systems.