A virtual tour from the Carpathian Basin to the Far East – an overview and synthesis of Eurasian forest-steppes

The post provided by László Erdős

According to the biophilia hypothesis of Edward O. Wilson, certain biological patterns evoke positive feelings in humans. As a considerable part of our evolution took part in savannas, so the argument runs, we are genetically determined to enjoy ecosystems with a savanna-like mosaic pattern of trees and grasslands. Some analyses have in fact shown that humans have an aesthetic preference for woody-herbaceous mosaics.

The hypothesis may be debated, but it certainly applies to me and the whole authorial team of the paper “The edge of two worlds: A new review and synthesis on Eurasian forest-steppes”, published in Applied Vegetation Science.

Granted, I like extensive forests and endless grasslands, but mixtures of these two habitats have always fascinated me. That is why I study forest-steppes. But what exactly are forest-steppes, and where can we find them? As it turned out, it is not very easy to answer these questions. Definitions and distribution maps abound in the literature, but they are usually contradictory. There are many case studies and even some reviews on national or regional scales, but a synthesis at the scale of Eurasia has been lacking.

After a few months of work spent in evaluating hundreds of forest-steppe publications, the situation that seemed difficult at the beginning became even more confusing. So I contacted some experts who are familiar with forest-steppes, and finally an international team emerged, formed by fourteen ecologists from six countries. I would have never imagined that so many different opinions exist regarding forest-steppes. Sometimes it seemed hopeless that co-authors could ever reach a compromise.

Finally, however, we accepted a definition that we think is broad yet accurate. It includes all types of forest-steppes. We firmly believe this definition works well, but we do not deny that it is somewhat arbitrary. Indeed, an exact forest-steppe definition is complicated by inherent ambiguity. It is clear that in nature a continuum exists, ranging from totally treeless grasslands to closed-canopy forests. Forest-steppes lie somewhere between the two extremes. The middle of the continuum is clearly a forest-steppe, but lower and upper thresholds can always be debated. Other problems of this kind are numerous. Constructive criticism and alternative definitions are welcome!

The largest part of our paper is about forest-steppe distribution and the delineation and brief description of the main forest-steppe regions. We hope this part can be used for education (for example, it may prove useful for biogeography courses).

If I try to explain why I enjoy walking and working in forest-steppes, the answer is biodiversity. First of all, there are so many kinds of forest-steppes, in lowlands and mountains, on sand and on rocky surfaces, some with an almost mesic character, others like a semi-desert. The high diversity of habitats is a core feature of all forest-steppes, but it is particularly conspicuous in the Carpathian Basin. You are in a shady and cool forest stand. Take a few steps, and you find yourself on a baking sand dune with sparse vegetation. A few meters away, in the dune slack, there is a small fen. Walk a bit farther, and you will be standing on the shore of an alkaline lake. Exceptional habitat diversity is accompanied by high species diversity and a remarkable number of endemics. The variety of life-forms and the colours of the flowers add to the beauty of forest-steppes. During botanical studies. I especially enjoy the company of animals. The European roller, bee-eater, and hoopoe are among my favourites, but I equally like the insect world: the swallowtail, the cone-headed grasshopper, the predatory bush cricket, and all the others. Sometimes I can hear the golden jackal, although I have not yet been lucky enough to meet one in person.

All in all, biodiversity explains why forest-steppes are so exciting. At the same time, they belong to the most threatened ecosystems on Earth, as pointed out in the final sections of our paper. Conversion to croplands, the spread of invasive species, afforestation, and the inadequate legal protection are the main factors that determine the present status of forest-steppes. The impact of climate change, combined with negative local or regional processes, may result in further forest-steppe decline.

However, there is some reason for hope. Forest-steppes have a long history of human presence, which proves that their sustainable use is possible. The scenic beauty of forest-steppes can be utilized in ecotourism. In some countries, the abandonment of former croplands provides a unique opportunity for grassland restoration. Grazing can be re-established in forest-steppe areas that are currently not grazed; grazing can be beneficial for biodiversity, and consumer demand for healthy products from free-ranging animals is expected to increase.

We hope that our paper will be useful for those who study forest-steppes. In addition, it is our hope that our review will encourage everyone to visit forest-steppes and discover their beauty.

László Erdős is a researcher at the Hungarian Academy of Sciences. The full Synthesis paper The edge of two worlds: A new review and synthesis on Eurasian forest‐steppes by Erdős et al. can be read for free in the Applied Vegetation Science (https://doi.org/10.1111/avsc.12382).