Direct and Indirect Effects of Management Intensity and Environmental Factors on the Functional Diversity of Lichens in Central European Forests

Abstract

Using 642 forest plots from three regions in Germany, we analyzed the direct and indirect effects of forest management intensity and of environmental variables on lichen functional diversity (FDis). Environmental stand variables were affected by management intensity and acted as an environmental filter: summing direct and indirect effects resulted in a negative total effect of conifer cover on FDis, and a positive total effect of deadwood cover and standing tree biomass. Management intensity had a direct positive effect on FDis, which was compensated by an indirect negative effect via reduced standing tree biomass and lichen species richness, resulting in a negative total effect on FDis and the FDis of adaptation-related traits (FDisAd). This indicates environmental filtering of management and stronger niche partitioning at a lower intensity. In contrast, management intensity had a positive total effect on the FDis of reproduction-, dispersal- and establishment-related traits (FDisRe), mainly because of the direct negative effect of species richness, indicating functional over-redundancy, i.e., most species cluster into a few over-represented functional entities. Our findings have important implications for forest management: high lichen functional diversity can be conserved by promoting old, site-typical deciduous forests with a high richness of woody species and large deadwood quantity.

Tree size drives diversity and community structure of microbial communities on the bark of beech (Fagus sylvatica)

“…This might be a result of a forest management plan that avoids clear cuts and carefully selects trees to harvest, which leads to a uniform forest structure in the study area (Schall et al, 2020). Based on a broader sampling including this and other two large forest areas in Germany, Boch et al, (2021) showed that an increase in forest management intensity is linked to reduced lichen species richness. A larger sampling effort covering a broader gradient of land-use intensity is therefore required to test whether the bark-associated microbiome differs in response compared to the macroepiphytes.…”

“…Biological and environmental factors driving diversity and community assembly in bark-associated epiphytes have been linked to forestry management, e.g., management intensity (Boch et al, 2021), forest homogeneity (Lamit et al, 2015), deadwood abundance (Boch et al, 2021), and tree age. For the latter, higher epiphyte diversities have been linked to the availability of large, old-growth trees (Aude and Poulsen, 2000; Nascimbene et al, 2013; Boch et al, 2021), probably because of higher niche partitioning in older trees (Łubek et al, 2020).…”

“…Biological and environmental factors driving diversity and community assembly in bark-associated epiphytes have been linked to forestry management, e.g., management intensity (Boch et al, 2021), forest homogeneity (Lamit et al, 2015), deadwood abundance (Boch et al, 2021), and tree age. For the latter, higher epiphyte diversities have been linked to the availability of large, old-growth trees (Aude and Poulsen, 2000; Nascimbene et al, 2013; Boch et al, 2021), probably because of higher niche partitioning in older trees (Łubek et al, 2020). At smaller spatial scales, abiotic drivers of bark-associated diversity and community structure include ultraviolet radiation, water shortages and correlated desiccation, poor nutrient availability (Lindow and Brandl, 2003; Vorholt, 2012; Leff et al, 2015), while biotic drivers include host traits, such as maturity of the substrate and host genotype (Arrigoni et al, 2018, 2020).…”

Tree Size Drives Diversity and Community Structure of Microbial Communities on the Bark of Beech (Fagus sylvatica)

“…Biological and environmental factors driving diversity and community assembly in bark-associated epiphytes have been linked to forestry management, e.g., management intensity (Boch et al, 2021), forest homogeneity (Lamit et al, 2015), deadwood abundance (Boch et al, 2021), and tree age. For the latter, higher epiphyte diversities have been linked to the availability of large, old-growth trees (Aude and Poulsen, 2000;Nascimbene et al, 2013;Boch et al, 2021), probably because of higher niche partitioning in older trees (Łubek et al, 2020).…”

Distribution Types of Lichens in Hungary That Indicate Changing Environmental Conditions

“…Investigations concerning the indicator nature of lichens were extended to the monitoring of land use intensity, and they were studied in a wider context [ 26 , 27 , 28 , 29 ], with due attention also given to the effect of the substrate [ 30 , 31 , 32 , 33 , 34 ]. For monitoring studies, the time passed has a key importance [ 35 ].…”