Dung Beetles are helping rainforests to regenerate
In contrast, dung beetles are negatively affected when an ecosystem is in trouble. Stress caused by environmental disturbances can cause dung beetles in tropical forests to gain weight and do less work. Species diversity declines.
As Amazon scientists, we use this hard-working, marvelous dung beetle as a way to assess the health of the largest rainforest in the world. We have studied more than 14,000 dung beetles of 98 species since 2010 in Brazil’s Santarem Region, a remote part of the Amazon rainforest. This is part of our long-term project for the Sustainable Amazon Network.
We studied dung beetles in order to determine the Amazon’s recovery after the extreme climate events, the most severe El Nino ever recorded.
The hard-working Amazonian dung beetle. Filipe Franca is the Author.
Stressed beetles eat less garbage.
El Nino’s fires scorched 4,086 square miles in the Amazon. These climate-triggered fires are not to be confused with last year’s Amazon fire crisis, which was deforestation-related. In our study, other Amazonian forest areas experienced extreme droughts but no fire.
Going into this project, we knew that Amazonian animals are more sensitive to fire than Australian animals, which had a long tradition of fire adaptation. Our study was published in February 2020 in the scientific journal Biotropica. It revealed that forest fires and dry weather are more destructive than previously believed.
Traps are baited – with what else? Human and pig poop. We count them and examine them physically. We trick the dung beetles by creating a small area on the forest floor with artificial seeds and a mixture of dung to assess their activity.
Researchers measure beetles dung removal and seed dispersal services. Marizilda Cuppre/ RAS Network, Author, provided
We found that 70% of the dung beetles were gone after El Nino. This is because heat from the fire will likely kill them. Most dung beetles are found in soils with a depth of zero to six inches.
El Nino droughts decimated Amazonian dung beetle populations. The populations of these insects dropped by 60% in forests that were only affected by fire and not by drought.
Extreme drought and forest fires in the Amazon severely reduced the beetles’ ability to remove dung from the soil and spread seeds. These abilities decreased by 67% and 22 %, respectively, compared to 2010 data before El Nino. This lower haul is likely the result of population decline.
Even two years after El Nino, the decrease in dung beetle captures and the reduced waste disposal function of these insects persisted. In fire-dependent ecosystems, the dung beetle population recovers quickly. However, in tropical forests, fires can cause insect populations to take years to recover.
Tropical beetles
The Amazon rainforests are in grave danger if both fire and drought kill the dung beetles.
In severely damaged forests, the majority of regrowth is dependent on animal dispersal. Dung beetles spread the seeds, which promote revegetation and help seedlings to survive.
Not only do they play this role, but other animals also do. Tapirs and Monkeys spread seeds to aid in vegetation regeneration. Ants, bee beetles, and wasps are also involved.
Many studies have shown that the dung beetle’s responses to environmental stress are similar to other seed-spreading creatures necessary for tropical forest health. Climate change is also causing the decline of these insect populations and killing ants. Bees. Butterflies.
Forests damaged by fire or drought will recover more slowly without these animals. This means that they could barely start their regrowth prior to the next disaster. Climate change is expected to cause more frequent and intense droughts in the tropics, along with higher and dryer global temperatures. This means that such disasters are likely to come more quickly.
We are cheering on all the tiny crawling and creeping creatures who run the world from our field sites in the Amazon. The humble dung beetle is a particular favorite.
