Unobtrusive and often unobserved, the insects, birds, and mammals that help to keep plant populations diverse and abundant are easily overlooked as they go about their tasks. Yet their contribution to food production in terms of quantity, quality, and diversity is incalculable, through the act of pollination – that quintessential symbiosis, which allows animals to draw nectar from plants while transferring pollen so that plants can reproduce.
Most wild plants rely on pollinators for fruit and seed set, including more than 70 percent of global food crops, which are dependent on animal pollination for yield or quality improvements. An estimated 88 percent of wild flowering plants globally are pollinated by animals. These include wild bees, butterflies, hoverflies, wasps, moths, and bats, to name but a few. Worldwide, there are around 20,000 species of bees alone but, together with other important pollinators, their numbers are dwindling – and with them the services that they provide to the ecosystem and to humanity.
Habitat fragmentation and intensive agricultural management are the main culprits, both of which have transformed natural landscapes beyond recognition over the past 50 years, triggering a domino effect that has serious repercussions for food security and livelihoods, compromising resilience to threats such as climate change and pathogens.
An essential source of pollination services, forests host a rich and complex array of nesting and foraging sites, and their presence is essential for the continued survival of a whole range of valuable insects and other animal pollinators. The close relationship within this tight-knit ecosystem means that the survival prospects of both parties are intertwined: pollinators rely on forests for their homes and food, while forests themselves depend on the services of pollinators for their natural regeneration and resilience through genetic diversity.
Perhaps ironically, despite the readiness of some landowners to rip out every tree or hedge, there is evidence that agricultural production can actually benefit from the presence of nearby forests and trees. It has been shown that agricultural landscapes adjoining fragmented forests and natural areas benefit from pollinator services, with animal-pollinated crops achieving higher fruit set as a result. For example, in West Java, Indonesia, an increase in tree cover – using mixed-tree agroforestry rather than monocrop rice paddy fields – led to 93 percent of the crop pollinators found in natural forest being maintained, with consequent benefits to agricultural production.
In some forest settings, especially in tropical countries, non-wood forest products such as Brazil nuts, latex, and palm fruits are essential sources of revenue for local communities, and pollinators play a critical role in assuring their reproduction. In India, a study found that 40 percent of 139 species important for local livelihoods benefited directly from biotic pollination, generally by bees and other insects. Açaí palm, a source of income for around 25,000 forest-dependent people in the Amazon River Delta, with an annual market value of USD 149 million, is highly dependent on biotic pollination, but intensive farming practices have eroded the relationship between surrounding forest cover and the ecosystem function of pollinators.
Climate change is likely to aggravate the precarious position of many of the planet’s pollinators. Extreme temperatures and events are affecting the animals and their habitats, while also leading to changes in the plants with which they have such a delicate relationship, affecting leaf unfolding, flowering, and fruit maturation. In Brazil, climate change is predicted to lead to a decline in yields of key crops such as tomatoes and coffee due to reduced pollination.
Landscape and forest management practices, especially those that promote a mosaic approach, can help to ensure the continued availability of pollinators and thereby increase resilience and productivity of both forestry and agriculture. Building connections between fragmented habitats, particularly through biological corridors or stepping stones made up of agroforestry, groups of trees or even single trees, has been shown to have a powerful effect in promoting the movement of pollinators and restoring their establishment and beneficial services.
Within forests themselves, practices that are conducive to maintaining healthy pollinator populations include regulating grazing in forests to minimize competition for floral resources, retaining dead standing and lying wood for nesting, and conducting selective logging, burning, mowing, coppicing, and thinning. In Germany, selective thinning was shown to increase flower budding, leading to a greater abundance of pollinators. It also resulted in improved fortunes for the threatened capercaillie through increased fruit setting of the bird’s main food source, the bilberry.
Despite their critical importance to food security, the role of pollinators has not been given sufficient attention in practitioners’ circles, especially in connection with forests. Yet the sustainable management of forests for pollination services can help to achieve the 2030 Agenda for Sustainable Development and its SDGs, in particular SDG 15 (life on land). A new report, ‘The Pollination Services of Forests,’ published by the Food and Agriculture Organization of the UN (FAO) and Bioversity International, presents a range of measures that forest and land managers could take to retain pollinators in forests and landscapes.
Any real progress in halting the loss of animal pollinators will involve innovative policy instruments, which create incentives for pollinators to be nurtured, such as payments for pollination services to land users who adopt landscape management practices that can attract and maintain pollinator populations. Let us remember the urgency of acting to protect our pollinators and make sure that we act now.
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This article was written by Sheila Wertz-Kanounnikoff, Senior Forestry Officer, FAO.