Habitat‐tree protection concepts over 200 years

The protection and sustainable management of habitat trees is an integral part of modern forest nature conservation concepts such as retention forestry. Not only bats and cavity-nesting birds, but also arboreal marsupials and a high diversity of saproxylic species are dependent on habitat trees and their great variety of microhabitats and old-growth characteristics. With a focus on insights from temperate forests, we trace the development of the habitat tree protection idea over two centuries. Foresters and natural scientists first conceptualized the idea of habitat tree protection in the early 19(th) century. At that time, utilitarian conservation efforts aimed at the protection of cavity trees that provided roosts and nesting holes for insectivorous bats and birds. By the second half of the 19th century, the idea of habitat tree protection was well known to forestry and had been occasionally implemented. The same is true for knowledge on the protection of large old trees, a special kind of habitat trees, for socio-cultural and aesthetic reasons. But many foresters of that time and in the following decades fundamentally rejected habitat tree protection for economic reasons. Beginning in the 1970s, forest nature conservation and integrative forest management became increasingly important issues worldwide. Since then, the protection of habitat trees was practically implemented on a large scale. We conclude that long-term views on the development of conservation concepts are important to inform the implementation of conservation today. In particular, historical analyses of conservation concepts allow the testing of long-term conservation outcomes and make it possible to study the resilience of conservation approaches to changing social or ecological conditions. We encourage all conservation ecologists to assess the practical and conceptual impact of the initial ideas that led to modern conservation concepts in terms of long-term biodiversity conservation. Article impact statement: It took 200 years to implement the habitat-tree protection ideas of far-sighted, trend-setting foresters and natural scientists. This article is protected by copyright. All rights reserved.