A Co-evolution of plants and animals
Large grazers belong to European nature. A large part of indigenous flora and fauna owes its existence to these herbivores. That is why AEK Nature is dedicated to having these animals back in nature areas and has already reintroduced herds of (half-) wild horses in dozens of places, and even occasionally beavers. In some larger areas, ARK is engaged in research on the return of the red deer and the elk and has also studied the process of how horses and bovids can be de-domesticated or become feral animals in social herds.
Why natural grazing
Originally, some tens of thousands of plant and animal species belong to the varied landscapes of Europe. Much of this richness in variety is the result of natural grazing, as large herbivores are fundamental to structure-rich grasslands, rough herbage and the transition areas to brushwood and forests. Almost all naturally grazed landscapes have disappeared. Many large grazers have been extirpated, domesticated or driven away to Europe's farthest corners. The natural-grazed ecological communities have made way for a disintegrated entity of pastures, meadowland, farmland and production forests. The ecological balance, related to the food and migration behavior of the large grazers, is gone. In modern nature management we try to restore this ecological balance. Safeguarding nature areas, connecting these areas wherever possible and letting large grazers return are logical measures to achieve a sustainable development of complete ecosystems.
Grazing as a natural process
Plant and animal species, which we have come to know from pastures, meadowlands, osier-thickets or moors, originate from a naturally grazed landscape. In the course of evolution, a fascinating relationship has developed between the plants and the herbivores: each herbivore developed its own food strategy. In their turn, plants armed themselves against these grazers by developing thorns or poison or by becoming unsavory. Other plants benefited from their presence because they could spread their seeds by way of the grazers or utilize their manure. Many animal species adapted to the grazing patterns, the manure of grazers or to the grazers themselves (predators, parasites). This allowed complex ecosystems to develop in which herbivores play an important role amidst thousands of other animal species and plants that depend directly or indirectly on these herbivores.
We can make far better use of grazing as a natural process with:
- mixed grazing by both horses and bovids, and preferably also by other grazers;
- breeds of animals that are closely related to their wild ancestors and that are able to survive in nature as much as possible without human interference;
- social herds, with a 1:1 sex ratio;
- low densities in line with the naturally available food supply in winter.
Species of grazers
There are herbivores in all shapes and sizes, but it is mainly the large grazers that can leave their stamp permanently and on a large scale on the landscape. The eight large herbivores that (may) play an important role in western European nature areas are: Beavers, Elks, Deer, Horses, Roe deer, Bovids, Wisent and Wild boar. Each species has its own place in nature, but there is an overlap in using the area: when different animals rely on the same food sources it may result in competition. But more often it is facilitation: one species creates the circumstances which are needed by the other.
Bovids, for example, which feed on long grass, may pave the way for horses, which live on shorter grass, which in turn, pave the way for grazing geese. Beavers create open, food-rich strips along the water, including beaver ponds which can go dry and subsequently become favorite spots for other grazers to gather. This is the reason why in natural grazing we must try as much as possible to let the total range of large grazer species return.
Not much is known about natural densities of horses and bovids. The usual rule of thumb for their wild offspring is that grazing density is determined by food supply in the most frugal season: early spring. Experiments on various densities of horse and cattle have been done in the small areas (2 - 250 hectares) belonging to ARK. In fertile river areas it showed that there was sufficient food for a density of 1 animal on 2 to 4 hectares of open terrain (not including forested areas). Densities are lower on poorer soil, such as on the edge of the Veluwe (Natuurmonumenten). The grazing density in the Oostvaarderplassen lake district has meanwhile increased to more than 1 animal per 2 hectares of open terrain. The animals seem to have adapted to food scarcity by cutting down their activity levels. Also, the phenomenon in the Oostvaarderplassen and the river area where the Konik mares are late in becoming fertile may be another adaptation to higher grazing pressures.
However, essential information is still lacking because of the homogenous landscape in the present grazing area. Only with a rich diversity of forest, open terrain, poor sandy areas and rich river forelands, brook valleys and rivers, can we know what biotopes the animals select and what densities are favorable. Brook valley and slopes have been connected in the Beneden-Geuldal for the first time. More of such areas are urgently needed.
Minimum surface needed for natural grazing
Even in very small areas of a couple of hectares, the (temporary) presence of a group of grazers may result in a fuller development of the natural richness. For practical reasons, 10 hectares will be the minimum surface on which the smallest unit of a social herd (such as a small harem, or a stallions or bulls gang) can survive for at least one year.
This of course on the condition that such a small, temporarily separated group will remain part of a larger population that has a much larger grazing area at its disposal. Hundreds of hectares of grassland are needed for a viable population of wild horses and bovids. The bigger the separate units become, the better the social herd-life can develop. Moreover, favorite grazing spots, tracks and watering places will become more clearly visible in large areas. Generally, the enriching influence that grazing has on nature and landscape will increase with the surface area of the grazing area.
Formation of patterns
The importance of natural grazing can be shown best with aerial pictures. The photographs below show the staggering patterns that have been formed by natural grazing. The spatial variety of tracks, short and long grasses, herbal flora, woods and brushwood and all their transitional forms make the habitat for thousands of plant and animal species. For reference there is another picture of the homogenous structure of meadows and grasslands with seasonal grazing.
Grazing and the formation of forests
In large parts of Europe, centuries of exploiting nature by agriculture and forestry created a landscape in which forests and grasslands have become two separate systems. Grasslands have been so intensively pastured or hayed that young bushes or trees can no longer develop. In forests, the production of timber is often central. Any clearing in the woods is often quickly replanted. The interface between closed forests and close-cropped grasslands is often a sharp contrast. In these separate worlds, the large grazers are domestic cattle on the pastures, and roe deer (sometimes red deer and boars as well) in the forests.
Few people realize that forest and grassland belong to each other by nature and even arise from one another. Free-roaming grazers play an important role here. Natural grazing, the formation of forests and the processes that break off the forest are, in fact, overpowering processes in the development of the European landscape.