How large herbivores like elephants, moose, and bison are helping to save the world's forests

Large herbivores like elephants, moose and bison are some of the most recognizable and iconic species on the planet. But they’re not just impressive to look at — their consumption of plant matter and movement throughout the landscape provide great benefits to the ecosystems in which they live.

In a new study, an international team of researchers used global satellite data to map the tree cover of Earth’s protected areas. They found that regions with an abundance of large herbivores in many different settings have a greater variety of tree cover, which is expected to be beneficial to overall biodiversity, a press release from Lund University said.

Megafauna, the largest animals in an area, play an important role in the maintenance of resilient ecosystems rich in many different species, which preserves biodiversity, as well as mitigating climate change.

The researchers looked at the complex relationships between tree diversity in the planet’s protected areas and the number of hungry herbivores.

“Our findings reveal a fascinating and complex story of how large herbivorous animals shape the world’s natural landscapes. The tree cover in these areas is sparser, but the diversity of the tree cover is much higher than in areas without large herbivores,” said Lanhui Wang, lead author of the study and physical geography and ecosystem science researcher at Lund University, in the press release.

The study, “Tree cover and its heterogeneity in natural ecosystems is linked to large herbivore biomass globally,” was published in the journal One Earth.

“In our global analysis, we find a substantial association between the biomass of large herbivores and varied tree cover in protected areas, notably for browsers and mixed-feeders such as elephants, bison and moose and in non-extreme climates,” said Jens-Christian Svenning, the study’s senior author and a professor of ecology at Aarhus University, in the press release.

The team found that a diverse vegetation structure is supported by large wild herbivores. The variety of vegetation is brought about by the animals’ massive consumption of vegetation, as well as the physical disturbances their foraging creates. This creates a rich habitat for numerous other species.

Wang said the findings point to the necessity of integrating large herbivores into conservation and restoration plans, both for their sake and for the essential role they play in influencing biodiversity and shaping landscapes. The research team argued that these contributions have not been adequately taken into account within the framework of ecosystem restoration and sustainable land management.

“At a time when global initiatives are intensely focused on combating climate change and biodiversity loss, our findings highlight the need for a broader and more nuanced discussion about ecosystem management and conservation measures. It is of utmost importance to integrate understanding of the ecological impact of megafauna into this,” Wang said in the press release.

More large herbivores living in the wild are needed around the world in order to achieve the restoration of thousands of square miles of ecosystems that 115 countries agreed to as part of the United Nations Decade on Ecosystem Restoration (2021-2030).

“I believe that we will need to protect and conserve large herbivores to achieve the UN goals. Megafauna are crucial for tree cover, which in turn promotes carbon sequestration and a diversity of habitats,” Wang added.