The Brazilian Cerrado is a hotspot of biodiversity. It is also quickly disappearing. Perhaps lesser known than the Amazon rainforest, the Cerrado, a unique area of tropical savanna habitat located in central Brazil, is the second largest biome in South America. Half of the Cerrado has already been cleared for agriculture, and less than 3% is strictly protected, which raises the question—what richness of life are we losing, and what have we already lost?
By studying plant-pollinator interactions in Brazilian Cerrado, I aimed to record and document pollinator species and the plants they interact with across a tree cover gradient in this threatened biome. Pollinators provided critical ecosystem services, such as crop pollination, and their interactions with flowering plants underpin the functioning of terrestrial ecosystems. I wanted to record these plant-pollinator interactions across the Cerrado in order to better understand the habitat needs of pollinators in Brazil’s tropical savannas, an understanding which can then inform efforts to restore and conserve land for pollinator diversity.
With the generous support of the Sir Peter Elworthy grant, I travelled to the state of Goiás in Brazil, where I had the incredible opportunity to work with postgraduate students and researchers from the Community Ecology Lab at Universidade Federal de Goiás (UFG). Together, we conducted two field seasons, collecting bees and recording plant-pollinator interactions across a tree cover gradient in Emas National Park.
Driving to Emas, corn and soybean fields blurred past the car window for hours. Red dust mired the skies, billowing up behind the trucks passing. The national park stood out as an island of native vegetation conserved in a landscape dominated by intensive agriculture. While agricultural fields are monotonous in terms of structure and diversity, the Cerrado forms a complex mosaic of vegetation structure, ranging from open grasslands to dense gallery forests. This mosaic is created over time, with dueling forces of fire and tree growth in play across the landscape.
My research questions focus on how this gradient of vegetation structure influences pollinators and their interactions with plants. To study this, we surveyed 15 plots established across a tree cover gradient in the park. I first walked the whole 50 by 50 meter plot with a handheld LiDAR scanner attached to a backpack, characterizing the 3D structure of vegetation within the plot. Then I would watch flowers within a smaller area of the plot, collecting any visiting pollinators for later identification by taxonomists. Repeating this process across our plots, I can begin to construct a network, or matrix, of plant-pollinator interactions across the park, investigating the role of vegetation structure in shaping these ecological networks.
The special thing about my fieldwork was the sort of mindfulness that it promotes. Watching flowers all day, ten minutes at a time, I gain an appreciation for the smaller things. Intricate interactions are happening all around us. You start to notice more. We caught myriad bees on flowering cashew plants. Snacking on the cashew fruits (which are often considered waste and thrown away in cashew nut production, despite the fruit’s nutritional value and tangy taste), we began to think about how many native cerrado plants, such as cashew, could benefit both pollinators and people, if used in more sustainable agriculture or agroforestry schemes.
