| Abstract |
Pollinators (like insects and birds) help sustain the human population. Without these animals, what would pollinate the plants and beautiful flowers that produce bounties of fruit and vegetables? Pollination is a very important ecosystem service when there is healthy order within the ecosystem. But pollinator populations are declining due to many factors, including pesticides, disease and climate change. So, how will that impact the entire ecosystem and how species within the community interact with each other? The loss of interactions between creatures that depend on each other is just as important as the decline of one animal or plant. Beatriz Lopes Monteiro of Sao Paula State University, Brazil, and colleagues from Brazil delved into the importance of specific pollinators in the Brazilian campo rupestre, a tropical mountain grassland ecosystem that includes 15% of Brazil's vascular plants, and how the loss of specific individuals could be detrimental to the complex network of interdependent species that comprises the community.The researchers looked at studies from 2012 and 2016 that had investigated pollinators – including hummingbirds, ants, beetles and bees – and their interactions with specific grassland plant species, recording over 1200 visits between specific pollinators and 163 grassland species in the Serra do Cipó National Park in Brazil. Lopes Monteiro and colleagues identified 318 pollinators visiting the national park's plants – some of which are native to the area, while others have been introduced – with bees pollinating 70% of the plant species, hummingbirds pollinating 11% and bats pollinating just 0.6% of the species.Then the team categorised which pollinators visited specific plants, breaking the ecosystem down into nine smaller sub-ecosystems – each containing specific plants and the pollinators that were most likely to visit them – to build a sense of how the plants and animals depend on each other. Impressively, the team revealed that one sub-ecosystem was mainly pollinated by flies, with two others pollinated largely by bees, while hummingbirds were active pollinators in three of the sub-ecosystems. And the team identified pollinators that moved between the sub-ecosystems, such as the glittering-bellied emerald (Chlorostilbon lucidus) and horned sungem (Heliactin bilophus) hummingbirds, which visited some of the sub-ecosystems, connecting them to hold the entire ecosystem together. And the plants that the pollinators visited were equally valuable to the creatures that visit, providing them with valuable nutrition. But which of the many plants and animals in the complex network are most crucial to the ecosystem's survival?The researchers identified nine – four plants and five pollinators – including the flowering plant Cuphea ericoides and the large bee Centris tarsata, with at least one of the threatened or native species in each of the sub-ecosystems. Thankfully, only one of the pollinators is in danger of being lost from the ecosystem, Augastes scutatus, a hummingbird species, while none of the plants are under serious threat. However, only two of the essential plant species are native to the campo rupestre ecosystem. Other important species include ones that visit a bunch of different flower species that are native to the ecosystem, such as the flowering plants Leiothrix arrecta and Aspilia jolyana. But some prominent pollinators are not native to Brazil, such as honeybees (Apis mellifera), which turns out to be a core pollinator, although they are not as efficient as wild, native pollinators and they often compete with the native bees for food, with potentially negative consequences for the environment. Conservation practices that encompass these networks (rather than just an individual) are a necessary step to trying to preserve as many species as possible during the current biodiversity crisis. |
