Stand structure and deadwood amount influences saproxylic fungal biodiversity in Mediterranean mountain unmanaged forests

Abstract

Old-growth forests are key elements of ecosystem diversity and conservation strategies, providing niche differentiation and trophic pathways that produce structural and compositional heterogeneity. In these forests, deadwood is particularly important for saproxylic and mycorrhizal fungi, sustaining forest productivity and environmental services. In this study, the saproxylic fungal diversity in Mediterranean mountain forests, characterized by different management histories and forest types (holm oak and beech), was analyzed. The relationships between saproxylic fungal biodiversity and structural attributes were considered in three forest stands of the Apennines (Italy). In addition, descriptive environmental parameters and forest traits were related to prevailing fungal communities, in order to analyze the species composition and distribution patterns of saproxylic fungi resulting from the ordination processes. The study sites were selected on the basis of their late-serial stage of development. Species frequency was analyzed through multivariate techniques to test the relationships between fungi, structural attributes and environmental variables. A Detrended Correspondence Analysis (DCA) was used to investigate the response of the overall fungal community structure to environmental gradients. Living tree volume, altitude, vegetation type, and the frequency of species with ephemeral sporocarp lifespan played a crucial role in diversifying species distribution patterns. Deadwood volume and decay classes were related to taxonomic and trophic community diversity. However, differences between the considered climatic regions exerted a major role on the occurrence of fungi with ephemeral sporocarps more than deadwood abundance, utilized primarily as fructification substrate.

Living and Dead Aboveground Biomass in Mediterranean Forests: Evidence of Old-Growth Traits in a Quercus pubescens Willd. s.l. Stand

“…The total living volume, amounting to 363.9 m 3 ha −1 , is much higher than that of old-growth oak stands from different Italian regions [49,50,68], where it did not exceed 300 m 3 ha −1 . It is also higher than what was recorded in more mesic Mediterranean forests, characterised by Quercus petraea in Sicily [54] and by Quercus cerris L. (Turkey oak) in Tuscany [24], and in oak stands not managed in more than 170 years [56]. The total basal area, equal to 34.4 m 2 ha −1 , is almost equal to that of a Quercus ilex stand in Tuscany, withdrawn from forest utilization since about 50 years [68].…”

“…Compared to Quercus ilex forest stands, a deadwood amount higher than 30 m 3 ha −1 is very close to that recorded in the Gargano wood [49], and it is far higher than that recorded in similar stands in Tuscany, Sardinia, and Lazio (Bertini and Fabbio in Bertini et al [50]). However, Quercus ilex stands may reach much higher values, ranging from 44 to 46 m 3 ha −1 ( [50,56], Bertini and Fabbio in Bertini et al [50]), so that 45 m 3 ha −1 could be considered a benchmark for thermophilous Mediterranean old-growth forests. By contrast, it is currently quite difficult to define a similar threshold value for Quercus pubescens old-growth forests, due to the lack of reliable data.…”

Influence of Anthropogenic Disturbances on Stand Structural Complexity in Andean Temperate Forests: Implications for Managing Key Habitat for Biodiversity

“…At the stand-level, structural complexity is the measure of a number of attributes present in a forest stand and the relative abundance of each of these attributes [2]. Studies have shown that stands with higher structural complexity generally harbor higher species diversity while promoting greater ecosystem functioning and stability in comparison to less complex ones [3–6]. Stand structural complexity can vary among different habitat types and successional stages [4,7,8].…”

Contrasting multi-taxa diversity patterns between abandoned and non-intensively managed forests in the southern Dolomites

“…Diversity patterns in no-and low-intensity managed forests types of dead wood in abandoned forests, which enhances the establishment of species that cannot be found on stumps in productively managed forests (Abrego & Salcedo 2013, Persiani et al 2015. We stress that the differences in diversity observed in mean species richness did not always reflect differences of total species richness.…”