Science and Technology Research News (EUA)

Pollination Is Threatened by Deforestation and Agrochemicals in Brazil

Publicado em 18 março 2019

Of the 191 cultivated or wild plants used for food production in Brazil and with a known pollination process, 114 (60%) depend on visits by pollinators, such as bees, to reproduce. These plants include crops of paramount importance to Brazilian agriculture, such as soybeans (Glycine max), coffee (Coffea), common beans (Phaseolus vulgaris) and oranges (Citrus sinensis).

Pollination is a vital ecosystem service guaranteeing food security and income for farmers, and its annual value is estimated to be R$43 billion (now approximately US$11.6 billion). However, pollination is increasingly endangered by a range of factors including deforestation, climate change and agrochemicals. Public policies that integrate actions in several areas, from environmental management to agriculture, science and technology, are needed to combat these threats, which jeopardize food production and the conservation of Brazilian biodiversity.

The numbers and wake-up call come from the First Thematic Report on Pollination, Pollinators and Food Production in Brazil, launched with a Summary for Policymakers on February 6, 2019, during an event at FAPESP.

The report is the result of a partnership between the Brazilian Platform on Biodiversity and Ecosystem Services (BPBES), supported by the FAPESP Research Program on Biodiversity Characterization, Conservation, Restoration and Sustainable Use (BIOTA-FAPESP), and the Brazilian Network on Plant-Pollinator Interactions (REBIPP). Twelve researchers took two years to write the report, which was peer-reviewed by 11 experts.

The researchers conducted a systematic survey of the scientific literature comprising more than 400 publications to produce a synthesis of current knowledge of and the risk factors that affect pollination, pollinators and food production in Brazil. The report also proposes measures to combat the risks and protect the pollinators.

“The report shows that pollination as an ecosystem service isn’t just important from a biological standpoint, for species conservation properly speaking, but also economically. This is the message we want to send to decision makers in the agribusiness sector. It’s a wake-up call about pesticide and land use in Brazil,” said Carlos Joly, Full Professor at the University of Campinas (UNICAMP), during the event. Joly is the coordinator of BIOTA-FAPESP and a member of the BPBES steering committee.

According to the report, the list of Brazil’s crop “visitors” comprises more than 600 animals, of which at least 250 are potential pollinators. They include butterflies, wasps, bees, bats, true bugs, and caterpillars.

Bees predominate, participating in the pollination of 91 (80%) of the 114 crops that depend on visits by pollinators. Bees are the sole pollinators of 74 (65%) of these crops.

Some cultivated and wild plants, however, depend solely or primarily on pollination by other animals. Examples include the bacuri (Platonia insignis), which is pollinated by birds; the sugar apple (Annona squamosa) and mountain soursop (Annona montana), which are pollinated by beetles; the mangabeira (Hancornia speciosa), which is pollinated by moths; and cocoa (Theobroma cacao), which is pollinated by midges.

“The cultivated and wild plants visited by these pollinators enrich our diet by providing fruits and vegetables that supply several important nutrients,” said Marina Wolowski, a professor at the Federal University of Alfenas (UNIFAL) and a coordinator of the report. “Wind-pollinated plants such as wheat or rice are staples, of course.”

The researchers analyzed the degree of dependency on pollination by animals for 91 plants that produce fruits, vegetables, legumes, grains, oilseeds and other edible parts, such as heart of palm from the jussara palm (Euterpe edulis) and mate tea from the yerba mate tree (Ilex paraguariensis).

The analysis showed that pollinators increase the quantity or quality of agricultural production for 76% of crop plants (69). Pollination dependency is very high for 35% of these crop plants (32), high for 24% (22), moderate for 10% (9), and low for 7% (6).

Based on the degrees of dependency of these 69 plants, the researchers estimated the economic value of pollination as an ecosystem service to food production in Brazil. They multiplied pollination dependency by annual crop production in each case.

The results point to approximately R$43 billion as the value of the pollination ecosystem service to food production in Brazil in 2018. Some 80% of this amount relates to four of the most important crops: soybeans, coffee, oranges, and apples (Malus domestica).

“This value is an underestimate, as the 69 crops in question account for only 30% of all the cultivated and wild plants used for food production in Brazil,” Wolowski said.

Risk factors

The report also emphasizes a number of risk factors that endanger the pollination ecosystem service in Brazil, such as deforestation, climate change, environmental pollution, agrochemicals, invasive species, diseases, and pathogens.

Deforestation leads to the loss of natural habitats and their substitution by urban areas. These changes reduce the supply of locations for nest building and the food resources available to pollinators.

Climate change may modify species distribution patterns, flowering times and pollinator behaviors. It may also lead to alterations in interactions, biological invasions, a decline in and extinction of plant species on which pollinators depend for food and nesting, and the emergence of diseases and pathogens.

The agrochemicals used to control pests and pathogens are highly toxic to pollinators, and their application frequently fails to take pollinators’ habits and visiting times into account. As a result, they can cause death or act as repellents. They may also have sublethal toxic effects, such as impaired navigation, flight disorientation, and reduced production of offspring. Pesticide use also tends to suppress or diminish the production of nectar and pollen by some plants, limiting the pollinators’ food supply, according to the report.

“Because these risk factors and the related threats to pollinators don’t occur in isolation, it’s hard to weigh each one separately in terms of its contribution to the reduction in pollinator populations observed worldwide,” Wolowski said.

Despite the adverse conditions, the authors of the report highlight several opportunities to improve the pollination ecosystem service, mitigate the risks to pollinators, and increase value added for the crops associated with them in Brazil.

Among the recommended actions related to conservation and management of pollination as an ecosystem service are ecological intensification of the agricultural landscape, alternative forms of integrated pest control and management, avoidance of pesticide overspill beyond the confines of croplands, organic farming, and environmental certification.

Formulation of a public policy for pollinators, pollination and food production would benefit the conservation of this ecosystem service and foster sustainable agriculture in Brazil, according to the report.

“We hope that the report will contribute to the formulation of strategic plans and public policy for pollination, pollinators and food production in different regions of Brazil,” said Kayna Agostini, a professor at the Federal University of São Carlos (UFSCar) and a coordinator of the report.

According to FAPESP President Marco Antonio Zago, the report covers a number of activities championed by BIOTA-FAPESP in its 20 years of existence. These include providing input for public policies.

“BIOTA-FAPESP participates actively in the life of São Paulo State and Brazil by providing scientific input for government decisions and at the same time conducting first-class research in vital areas,” Zago said upon opening the event.

Fernando Dias Menezes de Almeida, FAPESP’s Administrative Director, also attended the event opening.