Page 70 - FAO-IPCC Expert meeting on climate change

Appendix 01: Speakers’ summary notes
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Climate impacts on forest ecosystems and their pollinators, and impacts on food supply
INOUYE, DAVID W., STEIN J. HEGLAND, AND SIMON G. POTTS.
PLENARY SESSION 2:
CLIMATE IMPACTS ON LAND USE, FOOD PRODUCTION AND PRODUCTIVITY (INDIRECT IMPACTS)
The vast majority of cultivated and wild flowering plants benefit from animal pollination. Approximately
200,000 species of animals serve as pollinators. More than 75% of leading food crops and ca. 35 % of crop volume depend on the ecosystem service that pollinators provide, and this dependency is growing as shown by the >300% increase in volume of agricultural production dependent on pollinators since 1961. The global economic value of these crops is €211 – 518 billion/yr. Natural ecosystems are also dependent on pollinators, as almost 90% of wildflowers rely at least in part on animal pollination, and their pollination helps to maintain biodiversity and ecosystem functioning.
Both managed and wild pollinators are vital to agriculture, as some crops are not serviced well by honey bees, the predominant managed pollinators. In many cases benefits to quality and/or quantity of crop production result from wild pollinators’ activity. Bumble bees are now being commercially managed too, and while both managed and wild colonies can be excellent pollinators, wild populations of many species are now at risk, with some species thought to have
gone extinct in the past few years. In Europe, 26% of bumble bees are threatened and the United States has recently classified one species as threatened.
Pollination service is under threat due to climate change, habitat destruction, agricultural intensification, increased pesticide use, and other anthropogenic activities. Climate change may cause spatial or temporal mismatches between flowers and pollinators and affect the physiology of these mutualistic partners. Insect pollinators are relatively mobile and have been shown to be expanding ranges in latitude and altitude, presumably in response to the changing climate. But there is concern because if the spatial distribution of the crops and pollinators lose significant overlap, pollination deficits may result. A study of orchards in Great Britain makes this point as the projected distributions of trees and pollinators will have significant areas of non-overlap by 2050. Projected shifts of suitable areas for cultivation of Coffea arabica coffee and of cacao will result in some major producing areas losing production as suitable climate zones move up in altitude or change latitude.
Changes in the phenology of plants and pollinators are occurring in both wild and managed ecosystems, and we are just beginning to observe potentially negative consequences. In some cases previously synchronized interactions are being disrupted, as one partner’s activity period loses overlap with the other’s. At a minimum this will result in re- organized ecological communities, and at worst, in the potential loss of some species. A study of the phenology of apple trees and their pollinators makes this point. We can expect to see increasing examples of spatial and temporal mismatch of pollinators and the plants they visit.
Pollinator services from wild bees, which provide the most efficient and important pollination service worldwide, can be preserved and increased by increasing the amount of natural areas within and around farmed areas. This will provide the combination of nesting sites and floral resources necessary to maintain pollinators, and if these natural areas are in proximity to cultivated areas, the crops will benefit. There are now multiple examples of such benefits documented for coffee plantations and for mass-flowering crops in agroecosystems.
The recent IPBES report on Pollination, Pollinators, and Food Production provides some important, relatively inexpensive, and effective policy recommendations to help support pollinator populations. If widely adopted they could have significant impact on future food security.
FAO-IPCC Expert meeting on climate change, land use and food security