In a groundbreaking study conducted by researchers from Yale University and Memorial University of Newfoundland, the reintroduction of a bison herd to the Țarcu mountains of Romania has unveiled a promising avenue for carbon sequestration. The study, published in The Guardian, highlights the pivotal role of bison as ecosystem engineers and their significant contribution to mitigating carbon dioxide emissions.

Bison, once a keystone species in the American Great Plains before being hunted to near extinction, are renowned for their ecological impact. Their behaviors, such as rolling and packing down soil in wallows and grazing on various grass heights, play a crucial role in shaping their habitats. Recognized as ecosystem engineers, bison create conducive environments for other species, including providing nesting grounds for birds.

The research team, utilizing a model developed at the Yale School for the Environment, demonstrated how bison interactions within their ecosystem facilitate carbon capture and storage in soils. Contrary to traditional carbon cycle models that primarily focus on plant-microbe-atmosphere interactions, this study underscores the importance of considering animal-mediated effects on carbon cycling. Ignoring such effects could lead to a distorted understanding of ecosystem carbon dynamics.

Romania, once devoid of its native European bison population, witnessed a remarkable conservation effort initiated by WWF Romania and Rewilding Europe. In 2014, European bison were reintroduced to the Carpathian mountains, marking a significant step towards restoring the region’s biodiversity. The successful reintroduction led to the establishment of a thriving bison population, with more than 170 individuals roaming freely in the Țarcu mountains—a testament to the efficacy of conservation initiatives.

The ecological impact of the bison herd extends beyond biodiversity restoration. Grazing evenly across grasslands, recycling nutrients, dispersing seeds, and compacting soil to prevent carbon release, bison emerge as pivotal agents in ecosystem restoration and carbon sequestration. Professor Oswald Schmitz, lead author of the study, emphasizes the critical role of bison in maintaining balanced ecosystems and mitigating climate change.

The research findings reveal the potential of the bison herd in the Țarcu mountains to capture an additional 59,525 tons of carbon annually. This carbon sequestration capacity is equivalent to the emissions of over 43,000 gas-powered cars in the United States or 123,000 in Europe, underscoring the substantial climate mitigation potential of bison reintroduction efforts.

Moreover, the resurgence of bison in the Țarcu mountains has catalyzed eco-businesses and tourism centered around rewilding. The presence of bison has not only revitalized ecosystems but also spurred economic opportunities, demonstrating the synergies between conservation and sustainable development.

While the study focuses on the specific conditions of the Carpathian mountain grasslands, it offers valuable insights for global climate policymakers. Magnus Sylvén, Director of Science Policy Practice at the Global Rewilding Alliance, emphasizes the dual benefits of nature restoration and carbon sequestration. By harnessing the potential of rewilding initiatives, policymakers can address both biodiversity loss and climate change, paving the way for a more sustainable future.

The research extends beyond bison to explore the carbon sequestration potential of various species, including sea otters, musk oxen, and tropical forest elephants. These species exhibit similar promise in enhancing ecosystem carbon storage, presenting a compelling policy option with vast potential for climate mitigation.