Large animals in French forests contribute to plant diversity

By Michael Evans - 21 Mar 2011 11:27:0 GMT
Animals help increase diversity of plant life in forested areas of France

France is a large country, much of which is still rural. There are many forested areas with a great range of natural habitats and an environmental diversity leads to a multiplicity of wildlife.

While some species like bears, wolves, chamois and ibex are restricted to particular areas of the country and are generally only found in remote mountainous regions, animals such as roe deer, red deer, foxes and badgers are found almost everywhere.

Recent decades have seen a growth in populations of large forest animals in France, including populations of wild boar, whose numbers drastically declined as a result of intensive hunting, particularly in the north of the country.

These large animals are obviously responsible for a certain amount of damage, not only to bushes and young trees in the forests, but also to crops on nearby agricultural land. However, a study by the French environmental organisation Cemagref has shown that although they undoubtedly cause damage, these animals also help to increase the diversity of plant life in forested areas.

Cemagref researchers studied the floristic surveys carried out from 1976 to 2006 at Arc-en-Barrois in the Haute-Marne department, about 275 km southeast of Paris. This is a unique observation site in view of its long-term monitoring data.

They discovered that one plant, the gypsy flower, was not found at the time of the original survey and only began to appear in 1981. It is now widespread, particularly in areas most frequented by large forest mammals.

In spite of threats from a number of predators, researchers put down the plant's success to its ability to hang on tight.

The seeds of the plant are able to latch onto the fur of animals and in this way they have been disseminated, enabling the plant to settle far and wide. Also, it has the great advantage that with its rosette-shaped arrangement of leaves, although it is plainly visible, animals do not eat it because it contains toxic substances.

Excellent dispersal agents are the wild boars. The boar's fur has two layers, with an undercoat usually consisting of curly hair and stiff bristles, unlike red deer and roe deer with their shorter hair. Seeds can easily lock into the boars' fur and be transported over many kilometres.

The boars' behaviour is also a decisive factor in seed dispersal. When they wallow in mud, their fur picks up seeds that are then transported to dryer areas where the boars will scratch themselves, or rub against trees, or dig holes in the ground as they look for food.

Researchers have brushed the fur of boars that have been killed by hunters and have counted around 40 different types of seed species that are being transported. It would be quite fair to say that wild boars are the champions at seed dispersal.

This project has been funded by the Water and Biodiversity Department of the French Ecology Ministry for a period 2009 to 2011. Partners include prestigious veterinary and agricultural institutes and the National Agency for Hunting and Wildlife.