Habitat selection of an old‐growth forest specialist in managed forests

Abstract

Old-growth forest specialists are among the species most affected by commercial forestry. However, it is often unclear whether such species can persist and what their habitat needs are in managed forests. We investigated habitat selection of one such old-growth forest specialist, the white-backed woodpecker (Dendrocopos leucotos), a species highly dependent on dead wood and typically found in primeval forests. Our aim was to understand factors affecting occupancy probability in managed forests in Central Europe, based on detection/non-detection data in 62 squares of 1 km 2 in 2015 and 2016. We used occupancy models to compare a priori expectations about the relationships between occupancy and habitat characteristics at two spatial scales while accounting for imperfect detection. Occupancy was best explained by a proxy for food availability at a large (1 km 2) scale and increased with the abundance of emergence holes produced by saproxylic beetles on standing and lying dead wood. Furthermore, occupancy was positively related to the mean DBH (diameter at breast height) of live trees and standing dead wood at a small scale (0.25 km 2 with high amounts of dead wood). Detection probability was negatively related to time of day, date, and number of accessible survey points, and positively related to the number of observers. Our results demonstrate that detailed knowledge about a species' foraging ecology is important for its effective conservation as surrogate criteria such as dead wood availability might not reflect the key factors required. For white-backed woodpeckers, it is important that the available dead wood is sufficiently colonized by saproxylic beetles, and for the conservation of the species, the habitat requirements of saproxylic beetles thus have to be taken into account as well.

Heritage Trees as an Important Sanctuary for Saproxylic Beetles in the Central European Landscape: A Case Study from Litovelské Pomoraví, Czech Republic

“…We can agree with [58] that saproxylic beetles prefer free-growing large trees. These are equally important for other insects, plants, mosses, and also vertebrates, such as birds and bats [9,28]. Window flight interception traps are designed primarily for catching more active and flying species [63], and window traps are useful for comparing forest habitats [64].…”

“…In general, the diversity of saproxylic beetles increases with the amount of deadwood [24]. Standing deadwood hosts more beetles than lying deadwood [25,26], as well as lichens, birds, and bats [27,28]. In general, massive trees are preserved mainly in old game hunting areas, parks, pond dams, and orchards [29], or in agroforestry areas [30], and as prominent features in the landscape, such as heritage trees [5].…”

How to Increase Biodiversity of Saproxylic Beetles in Commercial Stands through Integrated Forest Management in Central Europe

“…by fungi, lichens, and mosses [34,54,82], also the group of Diptera [83]. This is also confirmed by the proven causality in the number of nesting birds in tree snags only when robustly colonized by saproxylic beetles [84].…”

“…With larger dimensions, however, deadwood in the form of trunk torsos and high stumps can host more microhabitats such as cavities, and thus be a hotspot for saproxylic beetles as well as nesting birds and bats. The larger the diameter of the tree, the more species of common and endangered beetles [110][111][112], as well as Picidae birds are found [84]. By contrast, fungi prefer lying deadwood [54].…”

Passive acoustic survey reveals the abundance of a low-density predator and its dependency on mature forests

“…Furthermore, as many species are related to old-growth forest attributes, both nest-site losses and habitat degradation are producing a decline of old-growth forest birds (Eggers et al 2005;Griesser et al 2007;Björklund et al 2015;Virkkala 2016). Indeed, if old-growth species occur in managed forests, such habitats are prone to becoming unsuitable for specialists if key resources are removed (Ettwein et al 2020). Therefore, establishing species-specific ecological requirements is crucial for developing evidence-based conservation strategies (Johnson 1980;Kristan 2006;Apolloni et al 2018).…”