Primeval conditions - what can we learn from them

摘要

In this paper I argue that prehistoric British forests and their avifauna were similar to those persisting in a near-primeval condition in the Bia?owie?oa Forest (Polish/Belarussian border). Therefore, observations in the Bia?owie?oa Forest may serve as a baseline against which effects of changes in the British woods can be assessed. The results of long-term (30 years) studies of the breeding birds in the Bia?owie?oa National Park are summarized. They reveal that the local avifauna shows some features (high species richness, low population densities, high nest predation and low production of young) regarded as typical for undisturbed tropical forests. It is proposed that high productivity, high population densities and sedentary habits found in many British populations are to a large extent a recent phenomenon, due to forest fragmentation, reduction of predator diversity and changes in forest structure. The necessity to preserve the whole Bia?owie?oa Forest - currently seriously threatened by ongoing logging - as a benchmark for future biological studies is underlined.