Forest management and regional tree composition drive the host preference of saproxylic beetle communities

Abstract

Summary1. Among saproxylic beetles, many early colonizers prefer particular host species. Ranking of preferred hosts of local saproxylic beetle communities is critical for effective dead-wood management in forests, but is rarely done because experiments with numerous tree species are labour and cost intensive. 2. We analysed the host preference of local saproxylic beetle communities on logs of 13 tree species in relation to management (unmanaged and managed beech stands, conifer plantations on natural beech sites) in three regions of Germany during the most critical period for host specificity, that is the first two years after harvesting. Hosts were ranked quantitatively based on the ordinal ranking of hosts by single beetle species, which in turn was based on the variation in beetle abundance. First, we employed a Bradley-Terry model in which ranking was derived from paired comparisons of host trees. Then, a model-based recursive partitioning of the Bradley-Terry model tested whether host preference of beetle communities is affected by stand management, region and decay progress of dead wood. 3. Our results indicated that beetle communities overall avoided logs of Fraxinus, Pseudotsuga, Larix and Tilia, and Carpinus ranked highest in preference. Carpinus also ranked highest for communities of broadleaf specialists; Picea abies ranked highest for communities of conifer specialists. Model-based recursive partitioning revealed that ranking of local hosts in conifer stands differed from that of broadleaf stands, and that ranking of hosts in broadleaf stands differed between regions, but only in the first year for both. 4. Synthesis and applications. Early-colonizing saproxylic beetle communities vary locally in their choice of host trees. Therefore, forest managers should focus on the enrichment of dead wood of regional tree species and tree species of the local stand to successfully promote earlycolonizing beetle.

Experimental studies of dead-wood biodiversity — A review identifying global gaps in knowledge

“…Various abiotic and biotic factors, e.g., climate, soil type and diversity of woody plant species, interact across a wide range of scales, e.g., biome, landscape and forest stand to determine the abundance and variety of resources available to saproxylic organisms ( Fig. 1; Müller et al, 2015;Stokland et al, 2012). Anthropogenic forces, such as extraction of fuel wood and timber, and conservation management represent the extremes of a gradient of forest-use intensity and also play important and sometimes dominant roles in influencing the amount, variety and distribution of woody debris across the landscape (e.g., Gossner et al, 2013b).…”

Coarse Woody Debris Variability Due to Human Accessibility to Forest

“…The deadwood decay process is complex and depends on a great number of factors, sometimes inter-linked: botanical species, forest age and management, climate and moisture content, the insect and fungi community [67][68][69]; CWD size and fragmentation contributes to the decay rate [57]. It must be noted that snags show a decay rate lower than logs [70][71][72].…”

“…Suitable density and different decay stages of snags are critical for the preservation of biodiversity and the constant functionality of forest ecosystems [40,79]. Müller et al [68] observed that many saproxylic beetles benefit from former fungal colonization, increasing species numbers in higher stages of wood decay. The level of snag decay is another important factor driving management decisions in sustainable forest management [62,77].…”

Drivers of CO2 Emission Rates from Dead Wood Logs of 13 Tree Species in the Initial Decomposition Phase

“…The dead wood logs of the 13 tree species ( [42]. Owing to limited supplies, P. avium logs are missing on 27, Acer spp.…”