Search

Question We compared active and abandoned beech coppices in terms of: (1) structural features, (2) total, understorey and overstorey plant diversity across spatial scales, and (3) species richness of beech forest specialist species. Location Central Apennines, Italy. Methods We applied a multi-scale approach, working at fine scale (management unit) and at a coarser scale (forest patch). Two forest patches were selected according to management regimes (active coppicing, 1-40 yrs; abandoned coppicing, >40 yrs) in each of the two study areas (Bolognola and Ussita). Within each forest patch, 20 stands were sampled in 20 m × 20 m plots, for a total of 80 sampling units. Results We found that the height of standards and number of dominant trees were negatively correlated with the total number of species. At the plot scale, the number of beech specialist species was significantly higher in abandoned plots. At the forest patch scale, the number of species in Bolognola was markedly higher in the actively coppiced forest than in the abandoned one, while the opposite result was found at Ussita. Regarding the beech specialist species richness, the abandoned forest at Ussita showed higher richness than the coppiced forest, while in Bolognola we found the opposite. The managed forest hosted more overstorey species than the abandoned one in both areas. Surprisingly, at forest patch scale in Bolognola, the total beech specialist species richness was higher in the coppiced plots than in the abandoned ones. The species assemblages were more similar between patches having different management regimes within the same area, than between patches having the same management regime across different areas. Conclusions This material provides a novel contribution to the study of species diversity patterns in this forest system, suggesting the importance of a multiple scale approach in forest diversity studies. The beech specialist species can largely persist in a heterogeneous coppice landscape, where abandoned stands are mixed with stands under regular coppicing. The results can link current knowledge about beech coppice diversity on the landscape scale with that on the plot scale, and thus help guide new conservation planning. [ABSTRACT FROM AUTHOR]

• Understorey specialists and generalists respond differently to forest maturity. • Specialists contribute more in shaping community-level leaf trait patterns. • Intraspecific variability can boost specialists' persistence with changing maturity. • Monitoring plans may focus on intra- and inter-specific responses of specialists. Coppice forest management impacts understorey vegetation. This is particularly true for habitat specialists (priority elements in conservation) who prefer closed canopy conditions associated with mature forests. Most trait-based studies of forest understorey focus on interspecific differences, which neglect the role of intraspecific variability. Here, we tackled this issue by examining how leaf traits respond (intra- and inter-specifically) to different stages of stand maturity for habitat specialist and generalist species. We measured the leaf area (LA), leaf dry matter content (LDMC) and specific leaf area (SLA) for 1,932 individuals belonging to 71 understorey species in 18 beech coppice forests grouped in three stages of stand maturity (i.e., post-logging, n = 5; recovering, n = 5; old stands, n = 8). We assessed leaf trait variation across stages of forest maturity for the entire community, and for specialists and generalists separately using monotonic trend tests. Then, we disentangled the proportion of variation attributable to intraspecific variability and interspecific differences of specialists and generalists using variance decomposition. We found significant positive trends in community-level SLA and negative ones in LDMC with increasing stand maturity. Beech forest understorey specialists (but not generalists) explained these patterns. The contribution of intra- and inter-specific components was dependent upon the trait under consideration and habitat specialization. For specialists, intraspecific variability was significant for all leaf traits and could explain 15.2% of model variance for SLA, 4.2% for LA and 3.1% for LDMC along the stand maturity gradient. Interspecific differences were significant for LDMC (29.8% of variance explained) and SLA (7.6%). For generalists, intraspecific variability was not significant; interspecific differences were significant for LA and explained 26.2 % of variability along the stand maturity gradient. We revealed that the maturity of coppice stands have different effects on generalist and specialist species. Habitat specialists are responsive to subtle changes in forest stand age both intra- and interspecifically, with their prevalence being function- and trait-dependent. Interspecific differences explained most of the LDMC (resource conservation) variance, while intraspecific variability accounted most of the SLA (light capture) variance. Generalists contribute to community-level trait variation, yet these species were less responsive to changes in forest stand age. To assess the impact of forest management on understories and refine the effectiveness of monitoring plans, we recommend focusing on habitat specialists, ideally including both trait variability within- and among-species. [ABSTRACT FROM AUTHOR]

This paper explores which traits are correlated with fine-scale (0.25 m2) species persistence patterns in the herb layer of old-growth forests. Four old-growth beech forests representing different climatic contexts (presence or absence of summer drought period) were selected along a north–south gradient in Italy. Eight surveys were conducted in each of the sites during the period spanning 1999–2011. We found that fine-scale species persistence was correlated with different sets of plant functional traits, depending on local ecological context. Seed mass was found to be as important for the fine-scale species persistence in the northern sites, while clonal and bud-bank traits were markedly correlated with the southern sites characterised by summer drought. Leaf traits appeared to correlate with species persistence in the drier and wetter sites. However, we found that different attributes, i.e. helomorphic vs scleromorphic leaves, were correlated to species persistence in the northernmost and southernmost sites, respectively. These differences appear to be dependent on local trait adaptation rather than plant phylogenetic history. Our findings suggest that the persistent species in the old-growth forests might adopt an acquisitive resource-use strategy (i.e. helomorphic leaves with high SLA) with higher seed mass in sites without summer drought, while under water-stressed conditions persistent species have a conservative resource-use strategy (i.e. scleromorphic leaves with low SLA) with an increased importance of clonal and resprouting ability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Alpha diversity measures do not capture crucial information about plant interactions. • We propose an index called Compositional Diversity which takes into account species combinations. • Old-growth forests have unique understorey species assemblages. • Restoring forest plant assemblages requires a longer time scale than restoring alpha diversity. • Species combinations may be used to assess whether a given forest has reached old-growth features. Biodiversity is changing rapidly, and ecologists use various measures to monitor and conserve it, but not all are equally effective. In the European temperate forests, ecologists are tasked with assessing the impact of global changes on plant species richness; however, this fails at capturing vital information about plant interactions. Using a chronosequence of beech forest stands, spanning 600 years of growth, we demonstrate the application of a different measure of diversity compared to classical species richness in the understorey. This measure, called compositional diversity (CD), considers the number of species combinations and their relative frequency within a community. The response of both classical species richness and CD along with succession, corresponded with our expectations based on ecological theory's U-shape prediction of diversity along the successional gradient. However, after 300 years, there was a significant decoupling between the two measures' responses. While species richness remained low and constant across old-growth and primeval forests, CD peaked in primeval forests, implying that the same number of late-successional species generated more diverse assemblages. This new information emphasises the need to protect old-growth and primeval forests not only to conserve species richness but also to preserve their unique network of species co-occurrence patterns – a factor not well represented by the classical species richness measure. [ABSTRACT FROM AUTHOR]