Old park trees: A highly desirable resource for both history and beetle diversity

Abstract

Many saproxylic beetles (those that live on dead wood) are confined to old trees. Because old trees have generally decreased drastically in number, many of these beetles are now red-listed, which means that they are on a list of species that are considered threatened by extinction from the area (often a country) that the list covers. Beetles dependent on old trees are found primarily in small remnants of semi-natural forests or on grazed land with old trees. However, parks around castles and manor houses also often contain old trees. This paper presents an inventory of saproxylic beetles in one such old, baroque park with an approximately 300 year-old avenue of lime (Tilia cordata) trees. The results are compared with a similar inventory of the most species-rich, old-tree site within the same region. It is a semi-natural forest, partly grazed, containing a number of old oaks. In the park, 18 red-listed beetle species were found - just a few less than the 22 found in the semi-natural forest. The results suggest that parks with old trees may be valuable sources of biodiversity. Because the number of old trees has decreased in the landscape generally, the remaining trees have become more important for the survival of the fauna associated with them. Cultural and biological values could be combined because both may be enhanced by retaining old trees. © 2004 International Society of Arboriculture.