Rewilding Romania: Bison return, biomass grows by 30%

ENVIRONMENT/ANIMALS

In the mountains of western Romania, a herd of shaggy giants is quietly changing the rules of the game. Where forests were closing in and fields turning uniform, plants are now bouncing back in new and surprising ways.

Conservation teams report that after a decade of rewilding work in the Tarcu Mountains, vegetation in some areas has increased by around 30%, both in volume and in variety. In practical terms, it means more grass, more shrubs, more flowers and a richer mix of habitats in the same landscape.

For scientists and local residents alike, the return of Europe’s largest land mammal is turning into a live demonstration of how bringing animals back can help heal damaged ecosystems.

The European bison once roamed much of the continent but were hunted until the last wild individuals disappeared in the early 20th century. By 1927, fewer than 60 survived in zoos and private parks, and only intensive breeding programs prevented the species vanishing altogether.

The comeback is now one of Europe’s most striking wildlife recovery stories. Together with WWF Romania, Rewinding Europe began releasing bison into the Tarcu range in 2014, creating what is considered the largest reintroduction project for the species in Europe.

Spain’s Museo Nacional de Ciencias Naturales notes Romania is key in this recovery, with bison living free in a huge mosaic of mountains and valleys rather than in fenced reserves. That detail matters because it allows natural behaviours such as long distance movement and seasonal migration to reoccur.

So why are scientists seeing more plants in a place full of one-ton grazers? The answer lies in the way bison eat, walk and rest. They graze open areas, trample shrubs, roll in the dirt and spread seeds in their fur and dung, which breaks up dense vegetation and opens patches of bare soil where new species can sprout.

Monitoring described by Click Petróleo e Gás points to an increase of about 30% in plant biomass and diversity in zones where the herd has been established for several years.

This is not a wall of identical greenery but a more complex mix of grasslands, shrubs and young forest standing side by side, which in turn supports more insects, birds and small mammals. Such a mixed landscape is exactly what many European species evolved with in the first place.

On paper, this sounds like a win. However, there is a downside: families who depend on cattle, hayfields and small plots for their income worry about fences being broken, haystacks being raided or herds meeting bison on narrow mountain tracks.

Project partners have tested a mix of solutions, from patrols and early warning systems to support for better fencing and plans to compensate farmers when damage occurs. And helping villages become “bison-smart communities”, where people learn how to avoid risky encounters and who to call when animals wander too close to homes. It is slow work, and trust has to be rebuilt each season.

At the same time, the bison are drawing visitors prepared to pay for guided tracking trips, local food and rural lodging. Conservation groups see this nature-based tourism as a way to help villages earn money from keeping the landscape wild, not just from logging or intensive grazing.

Across Europe, the disappearance of large herbivores over the past two centuries has left many ecosystems unbalanced. Forests have spread into former meadows, and some soils have lost their natural mix of grasses and herbs.

The Tarcu herd is now being watched closely as a real world test as to whether reintroducing big grazers can reverse some of that damage.

Scientists and conservationists use the area as an outdoor lab, combining data on vegetation, wildlife and carbon storage with interviews in nearby villages. WWF Romania reports more than 200 bison now living in the Tarcu range and more than 350 nationwide, and rangers are collecting genetic samples to see how healthy and diverse the population is.

The hope is that lessons learned here can be applied to other corners of the continent where big animals vanished long ago.

For the most part, the early results suggest that carefully planned rewilding can boost biodiversity, and even support local economies, as long as people are involved from the start and their concerns taken seriously.

The challenge now is to scale up without ignoring the everyday realities of life in mountain communities. 

TOP Bison return to the wild in Romania

So why are scientists seeing more plants in a place full of one-ton grazers? The answer lies in the way bison eat, walk and rest. They graze open areas, trample shrubs, roll in the dirt and spread seeds in their fur and dung, which breaks up dense vegetation and opens patches of bare soil where new species can sprout.

SOURCE