Magic of the Fallow

Insects need food and nesting places in sufficient variety, quality and connectivity. During the complex life cycle, different habitats are required for reproduction, larval stages, food intake and hibernation. The more structural diversity there is in a landscape, the more likely insects are to find suitable living conditions and habitats there.

Habitats for butterflies

Many insect species have been deprived of their livelihood in recent decades – through increased intensity of grassland management, the loss of fallow land, the elimination of small structures in the agricultural landscape (such as raines, hedges, flower and herb-rich borders and wetlands), growing homogeneity of cultivated areas, and loss of land through non-agricultural use.

Butterfly species are very good bioindicators. If the most sensitive and vulnerable species of a claim type are protected by improving their habitats, other habitat-typical species are also promoted.

Terrestrial microhabitats are habitats in the smallest space, which are characterized by their own microclimate (temperature, light, humidity), which is determined by the type and composition of the soil (e.g. also the proportion of raw soil), the type, density and height of the plants growing there, and the prevailing light conditions (shading).

Many butterfly species often prefer a warm-dry microclimate and lay their eggs on young host plants such as umbellifers (dill, parsnip, wild carrot) over raw soil or gravel, which warms up in the sun and creates a warm-dry microclimate favorable for many butterfly larvae.

Some butterflies also suck on wet soil or puddles to absorb dissolved minerals. Leaving unsievable surfaces offers these possibilities.

Microhabitats can be examined more closely with drones. The information obtained can then be used in ecological field research for larger areas, so that predictions can be made, for example, about the suitability of a landscape for butterfly egg deposition. The method of bridging scales (fine to large) can also be used to assess and verify the effectiveness of nature conservation measures. Thus, statements about the ecosystem functionality of a landscape can also be made.

Fallow land development

The structure of the vegetation is particularly important for the occurrence of insect species. A coexistence of all successional stages is necessary.

From the initial stage of a vegetation-free, bare raw soil, a stable final stage of a biocoenosis (plants, animals, fungal society – climax society) develops independently without regulatory intervention through various intermediate stages, which is adapted to the site-specific environmental factors (climate, soil). Provided that the environmental factors allow it and no further disturbances take place, fallow, abandoned succession areas in these latitudes develop in sequence (primary and secondary succession) via newly colonizing pioneers, such as prokaryotes, mosses, lichens, to grasses, herbs, perennials, bushes and forests. Weakly competitive species are displaced by strong competing species over time.

Often this development is disturbed or changed by e.g. storm, fire, rockfall, cattle kicking, machinery, ploughing or clearing. As a result, new areas are created from these disturbances.

Disturbed structures in ecosystems are often positive and absolutely necessary for the preservation of many, and here in particular the highly endangered butterfly species.

Necessary would be the reestablishment of extensive forms of use, small-scale mosaics with different uses and also dates of use and unregulated components of use. This would create important disturbance sites (in forests and on marginal sites or also on municipal green spaces or in private gardens).

What the individual can do:

Allow structural diversity, changing fallow land, in your environment as well – on a small and large scale. Give ruderal surfaces, mostly fallow raw soil areas, a chance or create fallow islands yourself. Allow leaves, rootstocks, puddles, and dead plant parts to lie wild. Cairns, wood piles, open ground, cracks, or holes in the ground offer important microstructures for many insects.

Then enable magical, fluttering diversity of insects and thus make a valuable contribution to the preservation of species diversity (biodiversity).


  • Fartmann, T. & G.Hermann (Hrsg.) (2006): Larvalökologie von Tagfaltern und Widderchen in Mitteleuropa.
  • Weidemann, H.J (1989a): Die Bedeutung von Sukzession und „Störstellen“ für den Biotopschutz bei Schmetterlingen