Take a Quick Look
- Study aims to prioritize the conservation of bees in forest restoration projects
- These insects are key in pollen transport of relevant tree species
- They can take pollen to farther areas and increase plant genetic diversity
Pollen transport of some of the most important tree species for the restoration and conservation of tropical forests depends on bees, whose flight ranges facilitate pollination at greater distances, contribute to increase the genetic diversity of plants and stimulate reproduction and the resistance of native species in degraded ecosystems.
That is why the conservation of bees should be prioritized in forest restoration projects, concludes a study published in Ecological Applications that analyzed how different species of bees respond to changes in Brazilian forest landscapes.
He also investigated how the increase in bee populations can increase pollen dispersion when planting in restoration projects and restore very diverse forests in disturbed areas in Brazil.
For this, the team of researchers carried out field work in an agricultural area of the Atlantic forest in southeastern Brazil that had become sugarcane fields.
There, only about 7 percent of its original vegetation remains in small fragments of primary forest , consisting of discontinuous canopies covered by vines and borders colonized by invading pastures.
In their study they also included two other less degraded remnant fragments as reference ecosystems. One of them is full of highly diverse trees reintroduced by researchers about two decades ago with the goal of protecting water bodies and increasing forest cover.
The other fragment is formed by wetlands created after sedimentation of water courses , now dominated by herbaceous vegetation.
“Restoration programs have the power to recover bee populations at the same time that bees can stimulate the reproduction and resistance of native species in degraded ecosystems.”Ricardo Ribeiro Rodrigues, Luiz de Queiroz Agricultural College, University of São Paulo.
In each of these areas, the researchers installed “trap dishes”, a standard method to capture bees, with the aim of collecting insect samples at the peak of the flowering season, between October 2015 and January 2017.
Then, they compared the abundance and diversity of bee populations with those of other habitats, and analyzed the pollen grains attached to the bodies of the captured bees to determine with which plant species they had interacted.
Thus they collected 727 individuals from 85 species of bees of different sizes and flight skills, social behavior, nesting site and breadth of the diet, and discovered that these bees had interacted with 220 different plant species.
The abundance of bees responded negatively to habitat change, decreasing in highly disturbed environments , such as anthropogenic wetlands (intervened by human action) and sugarcane fields, and increasing in restoration plants and forest fragments.
This is the case of some species of large and medium-sized bees that nest on the ground, and are predominantly found in preserved fragments and restored areas.
The team also found that species of small and medium-sized bees that nest underground, with varying levels of social behavior and diet, are not affected by habitat change, and even exhibit a tendency to increase in some disturbed areas.
Bee species that exhibit a reduced preference for pollen sources, typically to a single genus of flowering plants – called oligolectic bees – responded negatively to habitat change.
The results suggest that “restoration programs have the power to recover bee populations at the same time that bees can stimulate the reproduction and resistance of native species in degraded ecosystems,” Ricardo Ribeiro Rodrigues told SciDev.Net , Biologist of the Luiz de Queiroz Agricultural College of the University of São Paulo, specialist in forest recovery and co-author of the study.
“It is a positive feedback system,” he added. “Therefore, the conservation of bees should be prioritized in restoration programs by reintroducing nesting materials in cases of locally extinct species,” says Rodrigues.
He explained that the bee will return as time passes and the trees will grow, providing new nesting sites and plant substrates for reproduction.
“Brazil is rich in pollinator species like bees, but we urgently need a public policymore solid that guarantees its conservation, as are countries like the United States, the United Kingdom, France and Norway, ”said Vera Lúcia Imperatriz-Fonseca, a biologist at the Institute of Biosciences at the University of São Paulo. “Taking care of pollinators is a safe return for biodiversity, ” he said.
He also argued that bees are disappearing in many regions of the world and are analyzing the causes and consequences, as well as the strategies to solve this problem. “In this sense, the results presented in the study can help guide public policy actions to restore forest areas that include bees in their strategy.”