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Exploring the biodiversity of key groups in coppice forests (Central Italy): the relationship among vascular plants, epiphytic lichens, and wood-decaying fungi
Abstract
Sustainable Forest Management (SFM) indicators consider the main ecological and socioeconomic functions of forests but do not currently include some key groups widely adopted to assess the effects of forest management, such as herbaceous vascular plants, epiphytic lichens, and wood-decay fungi. Moreover, they are shaped into high forests while in the Mediterranean area the oldest type of forest management is coppice. We investigated the diversity and the relationships of the above-mentioned groups of taxa in three European Forest Types (EFTs) to contribute to the selection of indicator species suitable for monitoring Mediterranean coppice forests. We find only a weak cross-taxon congruence between vascular plants and lichens on considering the whole dataset, while no significant correlations are evident within the three EFTs. Species richness was significantly different among EFTs, being Thermophilous deciduous forests the richest, both considering the groups of taxa separately and the total species richness. As for species composition, significant differences were found both for the whole dataset and also for pairwise comparisons among EFTs. We provided a dwelling-species list of the three key groups of taxa, which could be suitable for monitoring the sustainability characteristics of fragmented and low continuity forests such as coppice stands.
• Highlights
• Vascular plants, epiphytic lichens and wood-decay fungi relationship in coppice stands
• Weak cross-taxon congruence between vascular plants and lichens
• Significant differences in species richness and composition among forest types
• We provide a list of dwelling-species suitable for monitoring coppices
... Therefore, host tree with rough bark serves as a suitable substrate for the attachment of epiphytes and furrowed bark enhance better moisture-holding capacity than smooth bark which often makes a poor host (Kellar et al., 2006;Wyse and Burns, 2011). Furthermore, leaf size and host tree architecture remain an important factor for epiphytic diversity patterns as it influences light levels and wind movement (Cardelus et al., 2006;Timsina et al., 2016;Frati et al., 2021). However, host tree bark pH was negatively associated with epiphytic abundance. ...
Vascular epiphytes contribute substantially to floral diversity, species richness, productivity, nutrient storage and complex arboreal communities in forest ecosystems. However, they have received insufficient attention due to accessibility limitations. In this communication, we analysed the vascular epiphytic species richness and composition in subtropical forests (from 400 to 1300 m) of Darjeeling eastern Himalaya. The study area was classified into three elevations (low, mid and high). We studied the correlation between vascular epiphytic richness and host tree traits such as circumference at breast height (CBH), bark texture and bark pH. Additionally, we applied Canonical Correspondence Analysis (CCA) to explain epiphyte diversity with respect to climatic variables (mean annual temperature, mean annual precipitation and mean annual relative humidity). In total, 942 individuals of vascular epiphytes belonging to 71 species under 46 genera and 21 families were recorded. Orchidaceae was by far the most species-rich family followed by the fern family Polypodiaceae. The results showed the species richness in mid elevations was comparatively lower than in the low and high elevations. Our study suggests that climatic variables and host tree traits such as CBH and bark texture were closely associated with epiphytic richness and diversity. These findings could be seminal in understanding the distribution pattern of vascular epiphytes and community composition with their relation to host tree traits. Nevertheless, effective and strategic conservation of vascular epiphytes must be considered in Darjeeling Himalaya.
... The diversity of the species and taxa sampled in this work was reflected in their different ecological roles and features within the community. For instance, most of the sampled lichens are known to be common on beech (Ravera et al., 2006;Nimis, 2021) and the number of recorded species was comparable to similar studies done on the Apennines Frati et al., 2021). Significant differences between the two study areas were reflected in the frequency of crustose pioneer lichens (e.g., Arthoniaceae and Lecanoraceae) and common generalist species (e.g., Lecidella elaeochroma, Physcia adscendens), while most of the species of conservation interest were exclusive of the CVDA. ...
Biodiversity monitoring represents a major challenge to supporting proper forest ecosystem management and biodiversity conservation. The latter is indeed shifting in recent years from single-species to multi-taxon approaches. However, multi-taxonomic studies are quite rare due to the effort required for performing field surveys. In this context, remote sensing is a powerful tool, continuously providing consistent and open access data at a different range of spatial and temporal scales. In particular, the Sentinel-2 (S2) mission has great potential to produce reliable proxies for biological diversity. In beech forests of two Italian National Parks, we sampled the beetle fauna, breeding birds, and epiphytic lichens. First, we calculated Shannon’s entropy and Simpson’s diversity. Then, to produce variables for biodiversity assessment, we exploited S2 data acquired in the 4 years 2017–2021. S2 images were used to construct spectral bands and photosynthetic indices time series, from which 91 harmonic metrics were derived. For each taxon and multi-taxon community, we assessed the correlation with S2 harmonic metrics, biodiversity indices, and forest structural variables. Then, to assess the potential of the harmonic metrics in predicting species diversity in terms of Shannon’s and Simpson’s biodiversity indices, we also fit a random forests model between each diversity index and the best 10 harmonic metrics (in terms of absolute correlation, that is, the magnitude of the correlation) for each taxon. The models’ performance was evaluated via the relative root mean squared error (RMSE%). Overall, 241 beetle, 27 bird, and 59 lichen species were recorded. The diversity indices were higher for the multi-taxon community than for the single taxa. They were generally higher in the CVDA site than in GSML, except for the bird community. The highest correlation values between S2 data and biodiversity indices were recorded in CVDA for multi-taxon and beetle communities (| r| = 0.52 and 0.38, respectively), and in GSML for lichen and beetle communities (| r| = 0.34 and 0.26, respectively). RMSE% ranged between 2.53 and 9.99, and between 8.1 and 16.8 for the Simpson and Shannon index, respectively. The most important variables are phase and RMSE of red-Edge bands for bird and lichen communities, while RMSE and time of tassel cap and from EVI indices for beetles and multi-taxon diversity. Our results demonstrate that S2 data can be used for identifying potential biodiversity hotspots, showing that the herein presented harmonic metrics are informative for several taxa inhabiting wood, giving concrete support to cost-effective biodiversity monitoring and nature-based forest management in complex mountain systems.
Although epiphytic lichens are widely adopted as environmental indicators, they are not yet included among the target species listed in Annex II of the Habitats Directive, to which the system of protected areas of the Natura 2000 network refers. In this work, we aim to test the effectiveness of this system, mainly designed for the conservation of other groups of species, in protecting lichen species richness. For this purpose, we considered a case study (Central Italy) with half of the territory included in protected areas. Statistical differences in species richness and lichen communities were tested between sites located in 16 Protected Areas (PA) and 11 Non-Protected Areas (NPA) using non-parametric tests, multi-response permutation procedures (MRPP), non-metric multidimensional scaling (NMDS) and Indicator Species Analysis (ISA). Despite the broad overlap between epiphytic lichen communities of NPAs and PAs and a similar number of total and common species, PAs contain a significantly higher number of nationally rare and extremely rare species, including cyanolichens. These results are also confirmed by the indicator analysis. Although the Natura 2000 network does not explicitly address the conservation of lichens, the protected areas in our study can play a role in protecting the diversity of epiphytic lichens, especially nationally rare and endangered species. However, the future inclusion of red-listed epiphytic lichens among the target species of Annex II of the Habitats Directive would be welcome to better protect these organisms on a European level.
Currently, forest ecosystems are often located in remote areas, far from direct sources of air pollution. Nonetheless, they may be affected by different types of atmospheric deposition, which can compromise their health and inner balance. Epiphytic lichens respond to air pollution and climate change, and they have been widely adopted as ecological indicators, mainly in urban and industrial areas, while forest ecosystems are still underrepresented. However, in recent years, their use has become increasingly widespread, especially in the context of long-term monitoring programs for air pollution in forests. In this review, we provide a critical analysis of the topic from the point of view of the different methodological approaches based on lichen responses adopted in forest ecosystems. Further, we discuss the main challenges posed by the current global change scenario.
Different European countries have interest in reviving the practice of coppice forest management. Despite in temperate forests the understory represents more than 80% of the plant diversity, it remains overlooked. The lack of knowledge is particularly evident for Italy, where coppice forests represent 42.3% of the forest cover and new demands for coppice revival are emerging. We reviewed the literature for Italy on the effect of coppice management on understory plants to summarise results, identify scientific gaps, propose research perspectives, and provide management suggestions. The coppice management cycle is suitable for a great number of species with different functional strategies. The environmental changes occurring during tree regeneration after coppicing lead to the decrease of understory species richness and changes in both species and functional composition. Old-coppice forests feature impoverished understories, but they are characterized by less ruderal and alien species, and by shade-tolerant species with traits typical of mature forests. However, several issues remain, leaving uncertainty on the effective coppicing impact on understory, in particular the cross-scale effects of coppice management and the complex response of different diversity facets. We propose future studies to focus on these issues to avoid misleading management messages to users and policymakers.
In forest ecosystems, a variety of abiotic and biotic soil forming factors drives soil organic matter (SOM) and nutrients cycling with a profitable outcome on climate change mitigation. As a consequence, type and intensity of forest management, through its impact on carbon (C) and nutrient soil stocks, can be considered as an additional soil forming force. In this study, we investigated the influence of the coppice conversion into high forest on pedogenesis and on soil C and nutrient (N, P, Ca, Mg, and K) stocks, fifty years later the beginning of the conversion-cycle. The trial was established in a Turkey oak forest historically managed under the coppice system in central Italy. Specifically, we considered tree population density (natural evolution – control, moderate thinning, heavy thinning) where soil samples were collected according to genetic horizon to estimate C, N, and P stocks both in the forest floor and at fixed depth intervals (0–30, 30–50 and 50–75 cm). Further, the stocks of exchangeable Ca, Mg, and K were also assessed for the mineral layers. The results showed that litter and the upper layer of mineral soil (0–30 cm) contained a similar quantity of C (about 74–83 Mg ha⁻¹), independently of the trials and no differences were observed also in the whole soil stocks (about 192–213 Mg ha⁻¹). The comparison of the mean stocks calculated per 1-cm of thickness of organic (O), organo-mineral (OM), and mineral (M) layers, although it did not display any difference among trials (excepted for P and Mg), showed a similar capability of the organo-mineral horizons to store C and nutrients compared with the organic ones (e.g., about 6–12 Mg ha⁻¹, 0.3–0.5 Mg ha⁻¹ and 0.5–1.5 kg ha⁻¹ for C, N and P, respectively). Our findings showed that thinning operated on Turkey oak coppice did not affect soil capacity to store C and nutrients. These results suggested that the forest ecosystem itself is the main soil forming force and this is consistent with the target of adopting forest management able to control the global C cycle through the storage of SOM in the mineral soil rather than in forest floor, where SOM turnover is faster.
There is a critical gap in our knowledge about sustainable forest management in order to maintain biodiversity with respect to allocating conservation efforts between production forests and set-asides. Field studies on this question are notably scarce on species-rich, poorly detectable taxon groups. On the basis of forest lichen surveys in Estonia, we assessed the following: (i) how much production stands contribute to maintaining the full species pool and (ii) how forest habitat conditions affect this contribution for habitat specialist species. The field material was collected in a “semi-natural forestry” system, which mitigates negative environmental impacts of even-aged forestry and forestry drainage by frequently using natural regeneration, tree retention, and low intensity of thinnings. We performed standard-effort surveys of full assemblages of lichens and allied fungi (such as non-lichenized calicioid and lichenicolous fungi) and measured stand structure in 127 2 ha plots, in mainland Estonia. The plots represented four management stages (old growth, mature preharvest forests, clear-cut sites with retention trees, and clear-cut sites without retention trees). The 369 recorded species represent an estimated 70% of the full species pool studied. Our main finding was that production forests supported over 80% of recorded species, but only one-third appears tolerant of management intensification. The landscape-scale potential of production forests through biodiversity-friendly silviculture is approximately twice as high as the number of tolerant species and, additionally, many very rare species depend on setting aside their scattered localities. The potential is much smaller at the scale of individual stands. The scale effect emerges because multiple stands contribute different sets of sensitive and infrequent species. When the full potential of production forests is realized, the role of reserves is to protect specific old-growth dependent taxa (15% to 20% of the species pool). Our study highlights that production forests form a heterogeneous and dynamic target for addressing the biodiversity conservation principle of sustainable forest management.
The effect of forest management on biodiversity is a crucial issue for sustainable forestry and nature conservation. However, the ways in which management affects macrofungal and plant communities and diversity of mountain temperate forests still remain poorly understood. We performed a random sampling stratified by stand age and stand type on the sites of temperate montane fir–beech forests. Diversity of macrofungi and the vascular plant understorey in beech- and spruce-dominated managed stands was investigated and compared to primeval forests located in the Poľana Biosphere Reserve, Western Carpathians. Both the vascular plant and the macrofungal communities were altered by management, and the response of the macrofungal species (especially wood-inhabiting fungi) was more pronounced in terms of species composition change. Species turnover evaluation seems to be an important tool of forest natural status assessment, because alpha diversity did not change as much as species composition. Certain species of Carpathian primeval forests were confirmed as good indicators for natural forest change; others were proposed. Species pool and mean number of species per plot were the highest in unmanaged fir–beech forests, and species diversity significantly decreased in spruce plantations. The number of species decreased significantly due to the change of canopy tree species composition only in the macrofungal communities. As an outcome for forest management, we recommend keeping mixed forests involving all natural tree species and providing at least a minimal amount of dead wood necessary for wood-inhabiting organisms and leaving some area of unmanaged natural forests within complexes of managed stands.
An updated inventory of the native vascular flora of Italy, providing details on the occurrence at regional level, is presented. The checklist includes 8195 taxa (6417 species and 1778 subspecies), distributed in
1092 genera and 152 families; 23 taxa are lycophytes, 108 ferns and fern allies, 30 gymnosperms and 8034 angiosperms. The taxa currently occurring in Italy are 7483, while 568 taxa have not been confirmed in recent times, 99 are doubtfully occurring in the country and 19 are data deficient. Out of the 568 not confirmed taxa, 26 are considered extinct or possibly extinct.
European beech (Fagus sylvatica L.) forests have a long history of coppicing, but the majority of formerly managed coppices are currently under conversion to high forest. The long time required to achieve conversion requires a long-term perspective to fully understand the implication of the applied conversion practices. In this study, we showed results from a long-term (1992–2014) case-study comparing two management options (natural evolution and periodic thinning) in a beech coppice in conversion to high forest. Leaf area index, litter production, radiation transmittance and growth efficiency taken as relevant stand descriptors, were estimated using both direct and indirect optical methods. Overall, results indicated that beech coppice showed positive and prompt responses to active conversion practices based on periodic medium-heavy thinning. A growth efficiency index showed that tree growth increased as the cutting intensity increased. Results from the case study supported the effectiveness of active conversion management from an economic (timber harvesting) and ecological (higher growth efficiency) point of view.
Since adequate information on the distribution of biodiversity is hardly achievable, biodiversity indicators are necessary to support the management of ecosystems. These surrogates assume that either some habitat features, or the biodiversity patterns observed in a well-known taxon, can be used as a proxy of the diversity of one or more target taxa. Nevertheless, at least for certain taxa, the validity of this assumption has not yet been sufficiently demonstrated. We investigated the effectiveness of both a habitat- and a taxa-based surrogate in six European beech forests in the Apennines. Particularly, we tested: (1) whether the stand structural complexity and the herb-layer species richness were good predictors of the fine-scale patterns of species richness of five groups of forest-dwelling organisms (beetles, saproxylic and epigeous fungi, birds and epiphytic lichens); and (2) the cross-taxon congruence in species complementarity and composition between herb-layer plants and the target taxa. We used Generalized Linear Mixed Models (GLMMs), accumulation curves and Procrustes analysis to evaluate the effectiveness of these surrogates when species richness, complementarity and composition were considered, respectively. Our results provided a limited support to the hypothesis that the herb-layer plants and the stand structural complexity were good surrogates of the target taxa. Although the richness of the herb-layer plants received a stronger support from the data than structural complexity as a predictor for the general patterns of species richness, the overall magnitude of this effect was weak and distinct taxa responded differently. For instance, for increasing levels of herb-layer richness, the richness of lichens showed a marked increase, while the richness of saproxylic fungi decreased. We also found significantly similar complementarity patterns between the herb-layer plants and beetles, as well as a significant congruence in species composition between herb-layer plants and saproxylic fungi. Finally, when different stand structural attributes were considered singularly, only the total amount of deadwood received support from the data as a predictor of the overall species richness. At the fine scale of this study, herb-layer plants and stand structural complexity did not prove to be effective surrogates of multi-taxon biodiversity in well-preserved southern European beech forests. Rather than on weak surrogates, these results suggest that sound conservation decisions should be supported by the information provided by comprehensive multi-taxonomic assessments of forest biodiversity.
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.
The authors conducted an ecological study of forests subjected to varying management. The aim of the study was to extend and integrate, within a multivariate context, knowledge of how saproxylic fungal communities behave along altitudinal/vegetational gradients in response to the varying features and quality of coarse woody debris (CWD). The intra-annual seasonal monitoring of saproxylic fungi, based on sporocarp inventories, was used to investigate saproxylic fungi in relation to vegetation types and management categories. We analyzed fungal species occurrence, recorded according to the presence/absence and frequency of sporocarps, on the basis of the harvest season, of coarse woody debris decay classes as well as other environmental and ecological variables. Two-way cluster analysis, DCA and Spearman's rank correlations, for indirect gradient analysis, were performed to identify any patterns of seasonality and decay. Most of the species were found on CWD in an intermediate decay stage. The first DCA axis revealed the vegetational/microclimate gradient as the main driver of fungal community composition, while the second axis corresponded to a strong gradient of CWD decay classes.
Copyright © 2015, Mycologia.
Effects of energy on species richness are a common, albeit complex, phenomenon, deserving of deeper and more systematic investigation by ecologists. A mechanism for species-energy relationships should be sought in the way that usable energy is divided among species, and in how the resulting patterns of local abundance affect incidence and richness in the landscape. Of particular interest is the very general model result that regional species-energy patterns have a stronger tendency to be positive than do local patterns, given a heterogeneous landscape. It is possible for the regional species-energy relationship in a heterogeneous landscape to be positive even when local relationships are hump-shaped or negative, a finding that agrees well with the empirically observed scale-dependence of the relation between species richness and measures of energy. This potential for diverse and conflicting yet mechanistic patterns at different scales may explain why it has been so difficult for ecologists to reach a consensus about the importance of energy in controlling species richness. -from Authors
Context In southern European beech forests coppice is a widespread management system, especially due to the past uses. The existence of large areas either abandoned or under protracted transitory stage raises questions concerning environmental and economic revenues related to the different management options.
Aims We evaluated the effectiveness of anticipating seed cutting in beech coppices to accelerate the coppice transition to high forest, compared with traditional management (periodic thinning) and natural evolution pattern (unthinned control).
Methods
We used an exploratory analysis of ecological variables related to structure, dynamics and productivity of the stands (growth efficiency, leaf area index, litter production, transmittance and canopy heterogeneity), which were monitored during 10 years in beech coppices in Central Italy.
Results
Anticipating seed cutting produced stronger modification in canopy structure, improving growth efficiency as a result of higher resource availability, supporting higher seed production which accelerated the progression of the stand towards more adult stand conditions, compared with traditional management and unthinned control.
Conclusion
The application of different active management options can increase landscape heterogeneity under conditions in which increasing landscape diversity represents a priority management issue, while simultaneously allowing environmental and economic revenues.
: We examined the concordance between vascular plants and macrofungi (grouped into trophic groups) in Mediterranean forest habitats (central Italy). Our goal was to test how consistently plant and fungi groups classify plots in a broadleaf deciduous forest dominated by Quercus cerris. Our hypothesis was that groups of plants can be used as surrogates for the classification of macrofungal communities. The test of concordance comprised two steps: 1) the plant species data sets were subjected to cluster analysis, to obtain three classifications based on presence of all plants, presence and frequency of only woody species; 2) Multiple Response Permutation Procedures (MRPP) was used to test the performance of each plant classification applied to the fungi data sets. The sample scores along the first PCA axis was used to investigate the relationships between compositional patterns. In the concordance analysis, the classification of only woody plants provided better results than the classification obtained with herbaceous and woody plants together. Cross-tests gave the best results when the “woody plants” classification was applied to ectomycorrhizal fungi (EMF) and, to a certain extent, to humicolous saprotrophs (Sh). The ordination analysis indicated that the frequency of woody plants follows a similar spatial distribution to EMF and Sh fungal groups and is therefore expected to discriminate the same environmental gradients. Many EMF exhibit preferences for few (one or two) hosts. Significant associations were found among a greater number of EMF and woody plant species. Woody plants such as Sorbus domestica and Prunus spinosa appear to be associated with many EMF. The combination of a high frequency of Fraxinus oxycarpa and Quercus petraea seems to promote distinct assemblages of EMF and Sh fungi. Then, characteristic assemblages of fungi were found in association with certain tree and shrub combinations.
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Knowledge of the number and distribution of species is fundamental to biodiversity conservation efforts, but this information is lacking for the majority of species on earth. Consequently, subsets of taxa are often used as proxies for biodiversity; but this assumes that different taxa display congruent distribution patterns. Here we use a global meta-analysis to show that studies of cross-taxon congruence rarely give consistent results. Instead, species richness congruence is highest at extreme spatial scales and close to the equator, while congruence in species composition is highest at large extents and grain sizes. Studies display highest variance in cross-taxon congruence when conducted in areas with dissimilar areal extents (for species richness) or latitudes (for species composition). These results undermine the assumption that a subset of taxa can be representative of biodiversity. Therefore, researchers whose goal is to prioritize locations or actions for conservation should use data from a range of taxa.
The present study investigated the effect of forest type on epiphytic lichen communities and selected indicator species, useful for long-term monitoring programs in Mediterranean forests. The results showed that only few species are common to many plots while others are locally rare. Epiphytic lichen diversity and communities were significantly influenced by forest type: Quercus cerris-dominated forests hosted a richer lichen flora, Fagus sylvatica-dominated forests showed the majority of rare species, while mixed forests, though poorly represented in the study area, hosted the majority of indicator species, revealing the presence of important and exclusive habitats. In particular, old established forests are characterized by both stand- and tree- continuity, while mixed forests offer a higher diversity of tree substrates. Our findings highlight the role of tree substrate variability for lichen colonisation. The presence of non-dominant tree species contributes to the variability of habitats and ecological niches. This allows the development of well preserved lichen communities compared to those of structurally less complex or even monospecific forests.
The present study investigated a fragmented Mediterranean oak forest to evaluate so called edge effect on species richness and composition of epiphytic lichen communities colonizing tree trunks.
The results showed that in Mediterranean oak forest patches, epiphytic lichen diversity and communities are significantly influenced by microlimatic variables related to the edge effect. Light influx rather than atmospheric humidity and temperature was the main driving factor affecting lichen diversity along the forest edge-interior gradient, while humidity is the prevailing factor inside the forest. It is concluded that forest fragmentation may have a heavy impact of epiphytic lichens, with the reduction and disappearance of typical forest species and the appearance of ubiquitous tolerant species, with an overall impoverishment and banalization of the lichen flora.
This study is focused on the selection of variables affecting lichen and bryophyte diversity in Mediterranean deciduous forests. Plots representing two forest types (Fagus sylvatica and Quercus cerrisforests) and two forest continuity categories (old-growth (OG) and non-OG forests) were selected in the Cilento and Vallo di Diano National Park (Italy). The presence and the abundance of bryophytes and epiphytic lichens were recorded. Structural variables of the forests and vascular plant species richness have been used as predictors. A strong positive correspondence between the two groups of organisms was found. Higher species richness and the distribution of rare species are related to OG stands, while a qualitative (species composition) rather than a quantitative (species richness) difference between the two forest types was observed. Some species elsewhere considered as indicators of forest continuity, such as Lobaria pulmonaria, Antitrichia curtipendula, and Homalothecium sericeum, are associated with OG forests, independently from forest type, suggesting that they can be regarded as suitable indicators also in Mediterranean forests. Finally, our results suggest that old trees, high levels of basal area, a broad range of diameter classes, and high understory diversity are the main structural features affecting cryptogamic communities, while no correlation was found with the occurrence of deadwood.
We tested whether the conspicuous lichen Lobaria pulmonaria indicates the number of tree‐dependent, red‐listed species in a hemiboreal forest in southern Sweden. In 18 naturally regenerated, mainly old deciduous forest plots considered to be of high or very high conservation value, the number of red‐listed tree lichens or wood beetles was not positively correlated with the area of the forest stands studied (8–56 ha). The 8 stands with L. pulmonaria had about nine (median) red‐listed lichens, but 10 stands without L. pulmonaria had only about one such species, a highly significant difference. Similarly, the variation between stands in the number of red‐listed wood beetles was considerable, but it was very weakly correlated with the number of red‐listed lichens. The number of red‐listed wood beetles dependent on dead trees was not different in areas with or without Lobaria pulmonaria, but the number of red‐listed wood beetles dependent on hollow trees was higher in stands with Lobaria pulmonaria (median of seven species) than in those without (three species) the lichen. Stands with this lichen species also contained significantly more of other types of lichens that have been proposed as indicators of forest continuity according to three lists. We stress the need for identification of species that could serve as indicators of different types of forest continuity and identify some organism groups that may indicate the different types .
Los líquenes y coleópteros dependientes de árboles como indicadores en los bosques bajo conservación
In the last decades, several methods were proposed for assessing environmental quality — mainly air pollution — on the basis of lichen data (see chapter 4, this volume). At the end of the 80s the predictivity of 20 different methods with respect to instrumental pollution data was tested in Switzerland using multiple regression [1, 5]. The highest correlation was found with the sum of frequencies of lichen species within a sampling grid of 10 units positioned on the trunks of free-standing trees. This method was immediately and widely adopted in several other countries, esp. Italy and Germany, with some modifications, chiefly concerning the size of the sampling grid. Since 1987, hundreds of studies were carried out with this approach, which led to its standardization in the form of guidelines both in Germany [13], and in Italy [7].
Epiphytic lichens represent one of the most suitable indicators of forest continuity and management, especially in the context of ancient and old-growth forests. Nevertheless, they have not yet been included among Sustainable Forest Management (SFM) indicators to which Pan-European forest policy and governance refer. In addition, currently adopted SFM indicators are mainly designed for high forests rather than coppice forests, despite the fact that today this management system covers more than 10% of the total European forests. In this study we investigated these two issues by examining epiphytic lichen diversity in three coppice forest stands, located in the two Italian regions of Tuscany and Sardinia. In particular, we addressed: i) the role of lichen diversity as SFM indicator and ii) its relationship with consolidated and new SFM indicators dealing with structural, health, biodiversity, protective and socioeconomic functions. Multivariate Factor Analysis and Generalised Linear Models were adopted for data analysis. We found that lichen diversity and the frequency of single sensitive species were mainly related to the biodiversity of plants and fungi (Criterion 4), the health and vitality of the forests (Criterion 2) and their protective functions (Criterion 5). Furthermore, our results show that the lichen species highlighted by the models may represent suitable indicators in long-term studies, especially in relation to complex and interconnected aspects of sustainable forest management. Although our findings represent a first contribute to this issue, more in-depth researches will be needed to clarify further aspects of the complex interactions among SFM indicators in the context of coppice forests.
The influence of forest management on fungal diversity and community composition has been the subject of a wide number of studies over the last two decades. However, the difficulty of studying the complex kingdom of fungi under real forest conditions has led to rather scattered scientific knowledge. Here, we provide the current state of knowledge suggesting future research directions regarding (i) stand structure attributes (age, tree cover, stand density, tree species composition), (ii) management history (managed vs unmanaged), (iii) silvicultural treatments (thinning, clearcutting, shelterwood methods, selective cutting) and (iv) other anthropogenic disturbances (mushroom picking, salvage logging, prescribed burning, fertilization) affecting fungal diversity and community composition. The reviewed studies reported a positive correlation between fungal diversity and stand structure variables such as canopy cover, basal area of the stand and tree species diversity, particularly for mycorrhizal species. Abundance and diversity in size, tree species and decomposition stage of deadwood are reported as positively related to richness of wood-inhabiting fungi. The main findings about the effects of silvicultural practices suggest that the higher is the management intensity the lower is the diversity of ectomycorrhizal and wood-inhabiting species, at least in the short term. We have therefore reported those silvicultural practices which may reduce trade-offs between timber harvesting and fungal diversity conservation. Indeed, fungal diversity can be conserved in managed forests if (i) low impact logging operations are performed; (ii) stand structural complexity and late-successional forest characteristics are enhanced; (iii) deadwood amount and diversity is promoted, (iv) landscape heterogeneity and connectivity is improved or maintained.
Aim: We investigated the consistency between richness and trait-based diversity metrics in capturing the e ects ff of management-related habitat factors on biodiversity. The choice of biodiversity metrics can substantially a ect ff the evaluation of conservation tools. However, the relative sensitivity of di erent metrics is not well in-ff vestigated, especially in a multi-taxon framework. Location: European beech forests in Denmark. Methods: We studied 20 beech stands comprising four management types (from intensively managed to long unmanaged stands). We analyzed how management-related environmental variables were re ected in the fl measure of: (i) species richness, (ii) number of conservation-relevant species (red-listed species and old-growth forest indicators) and (iii) functional diversity targeting ve organism groups with di erent habitat require-fi ff ments, i.e. vascular plants, epiphytic lichens and bryophytes, saproxylic fungi and breeding birds. Results: Plain species richness at stand level was generally misleading, as it did not capture changes in the number of conservation relevant species with changes in management-related environmental variables. The interpretation of functional responses was most informative for the better known vascular plants, while responses were more fragmented for the other organism groups. Overall, however, functional responses were consistent with a loss of specialization and progressive simpli cation of species assemblages from long-un-fi managed to intensively managed stands. Conclusions: Our ndings suggest that the occurrence of conservation-relevant species is a sound and relevant fi metric for planning and evaluating conservation actions, especially for less studied organism groups (e.g., sa-proxylic fungi and epiphytes). The functional approach is promising, but presupposes the availability of databases of relevant traits.
Aim
Biodiversity monitoring and conservation are extremely complex, and surrogate taxa may represent proxies to test methods and solutions. However, cross‐taxon correlations in species diversity (i.e., cross‐taxon congruence) may vary widely with spatial scale. Our goal is to assess how cross‐taxon congruence varies with spatial scale in European temperate forests. We expect that congruence in species diversity increases when shifting from fine to coarse spatial scales, with differences between species richness and composition, and across pairs of taxonomic groups.
Location
European temperate forests.
Time period
Present.
Major taxa studied
Vascular plants, bryophytes, birds, epiphytic lichens, saproxylic beetles and wood‐inhabiting fungi.
Methods
We used field data (354 plots across 23 sites) encompassing Italy, France and Hungary, with species information for six taxonomic groups. We accounted separately for spatial grain (the size of elementary sampling unit) and extent (the geographical area included in the survey) and evaluated the relationships within all the possible pairs of taxa.
Results
Although no pair of taxa had its species richness consistently correlated across scales, we found no changes in the direction of correlations when analysing species composition. However, when increasing grain and extent, we did find a general increase in the magnitude of correlations in species composition and partial changes in significance, with plants having the highest number of significant correlations.
Main conclusions
Species richness congruence among taxa is strongly scale dependent owing to differences in the relative contribution of large‐ and small‐scale processes across taxa. Cross‐taxon congruence in species composition is scale dependent only for its magnitude, because life‐history traits of individual species make responses to environmental factors similar across scales. Forest monitoring should consider multi‐taxon sampling and limit the use of surrogates at specific spatial scales, especially for species richness. Sampling plant species composition in scattered plots across different sites may effectively summarize the whole community composition.
An updated inventory of the vascular flora alien to Italy, providing details on the occurrence at regional level, is presented. The checklist includes 1,597 species, subspecies, and hybrids, distributed in 725 genera and 152 families; 2 taxa are lycophytes, 11 ferns and fern allies, 33 gymnosperms, and 1,551 angiosperms. 157 taxa are archaeophytes and 1,440 neophytes. The alien taxa currently established in Italy are 791 (570 naturalized and 221 invasive), while 705 taxa are casual aliens, 4 are not assessed, 7 are of unknown regional distribution, 47 have not been confirmed in recent times, 3 are considered extinct or possibly extinct in the country, and 40 are doubtfully occurring in Italy. This checklist allows to establish an up-to-date number (9,792) of taxa constituting the whole (native and alien) Italian flora.
Multi-taxon analyses of ecological assemblages are needed when the effects of forestry on biodiversity are examined. Management usually simplifies the structure of forests, which results in quantitative and qualitative declines in many microhabitats and species associated with them. In Fennoscandia, most forests are managed for industrial use of wood, but relatively little is known about the relationships between structural components and biodiversity in managed forests. Abundance, composition or species number of different species groups reacting similarly to variation in their environment would be a useful tool e.g. in estimating responses of species that are more difficult to sample. Thus far evidence for, or the lack of, such congruence or indicator functioning is not conclusive. We therefore examined the associations between stand structural features and species diversity and congruence between species groups of vascular plants, bryophytes and lichens, polypores and beetles. Our study was carried out in mature managed Norway spruce dominated forests in Southern Finland in 2009. Our main findings were (1) cross-taxon congruence in species richness was generally low, suggesting that any single taxonomic group performed poorly as an indicator of overall biodiversity; (2) the volume and diversity of dead trees were the most frequently detected significant predictors of species richness of the studied groups; (3) in terms of species composition, only vascular plants co-varied significantly with bryophytes and lichens; in addition, bryophytes and lichens as well as polypores co-varied significantly with stand structural features; (4) species composition of vascular plants, polypores and saproxylic beetles was associated with the volume of living trees, and in polypores it was also associated with the volumes of both dead and living deciduous trees. These results suggest that biodiversity monitoring for management and conservation requires data from several taxa. However, the volume and diversity of dead wood are useful indicators of stand-level species richness of several taxa, whereas the volume of living trees is an important indicator for the stand-level species composition of several groups. Thus, these structural variables have the potential to function as easily attainable indicators of general forest biodiversity.
Cross-taxon surrogacy (between-taxon similarities in species patterns) can help conservation biologists to design simplified, standardized and efficient tools for biodiversity monitoring. Our study aims to identify potential sets of indicator taxa to be recommended in temperate forests. We focused on nine forest taxa: vascular plants, bryophytes, saproxylic beetles, polypores, lichens, ground beetles, hoverflies, birds and bats. We assessed crosstaxon congruence patterns, in terms of both alpha and beta-diversity, using empirical biodiversity data from 206 plots in ten French forested areas. We evaluated the cost-efficiency of potential surrogate taxa using both strictly encoded expert knowledge and results of this study. The most congruent taxa in alpha-diversity were bryophytes (with bats and polypores), and ground beetles (with bats and saproxylic beetles), though levels of covariation were mostly weak. The most congruent taxon in beta-diversity was vascular plants (with bryophytes, ground beetles, lichens and forest birds). Contrary to our expectations, the subsets of forest species within a given taxon exhibited a lower surrogacy than the taxon as a whole. Four categories of taxa were delineated based on costefficiency scores – from costless but ineffective (bats and ground beetles) to costly but effective (saproxylic beetles and polypores). No single taxon was firmly identified as a relevant surrogate for other taxa; using a set of two or three taxa drastically increased surrogacy, compared with single-taxon approaches. Saproxylic beetles associated with vascular plants, or with both vascular plants and birds, seemed to be the most cost-efficient associations. Further research is required to up-scale our results from the short-term, local scale to the long-term, landscape scale in European temperate forests.
A major question in fungal conservation is why many species are confined to old forests, and how they could be supported by contemporary landscape matrix. Specifically, forestry that retains large biological legacies across landscape could reduce old-forest dependencies to species that require unusual substrate conditions. We sampled polypores in 112 2 ha plots (both old and harvested stands) in a semi-natural forestry context in Estonia and modelled the habitat factors of species confined to old growth. The results confirmed that old-growth assemblages emerged mostly due to diverse and abundant substrate supply (notably downed CWD). Only 10 species (five spruce-dwellers) were confined to old growth; of these, only Fomitopsis rosea and Oxyporus corticola were additionally affected by forest connectivity. The forestry system studied appeared particularly favourable for the species inhabiting deciduous wood. To better address habitat degradation in conservation, expert lists of ‘old-forest (indicator) fungi’ should be replaced with evidence-based focal taxa.
The effectiveness of surrogate taxa as ecological indicators for biodiversity assessment and monitoring depends on different factors, such as the spatial scale of analysis. In this study we explored the effects of the grain size and the choice of predictor variables on the strength of the community congruence relationships between vascular plants, bryophytes and lichens. Community data for these taxa were collected using a restricted random sampling applied in the Bosco di S. Agnese Nature Reserve (Tuscany, Italy). Co-Correspondence analysis (Co-CA) was performed on two different response communities (e.g. bryophytes and lichens presence/absence data) considering three predictor communities (presence/absence of vascular plant, abundance of vascular plants and a structure-based dataset) for three grain sizes (1m2, 100m2, 10000m2). The effects of spatial grain and the type of predictor variable on the strength of the congruence among the considered taxonomic groups were twofold: i) the amount of explained variance depends on the grain size; ii) the sign of observed relationships mainly depends on the analyzed taxon and on the choice of predictor variables. Our results highlight the importance of plot dimension, choice of predictor variable and taxon identity in evaluating cross-taxon relationships and provide further insights on the limitations of cross-taxon estimates among vascular plant and cryptogams for biodiversity assessment and conservation planning.
With reference to the UK and W Europe, outlines the types of woodland structure found today (coppice woodlands, high forests, pasture woodlands) with comments on associated bryophyte and lichen taxa. Emphasis is placed on the implications of pasture woodlands for the persistence of rich epiphytic floras. Use of lichen indicator species in characterising ancient woodland is examined. Brief comments are given on old forest species and forest management outside Europe. -P.J.Jarvis
We tested the hypothesis that structural variables related to old-growth features affect the distribution
of Lobaria pulmonaria in a Mediterranean National Park of Italy. A total of 36 plots, with old-growth
characteristics and representing overall three forest types (beech- oak- and mixed- forests) were studied.
The lichen was absent in about half of the sites, suggesting that the selection of old-growth forests based
solely on structuralfeatures is not sufficientto predictthe presence ofthis species, which therefore proves
to be rather sensitive and selective. Its abundance was related to high tree circumference and basal area,
and to availability of deadwood, confirming the relevant effect of substrate and stand continuity in the
conservation ofthis species and emphasizing its role ofindicator species of undisturbed forest ecosystems
with long ecological continuity.
We tested the hypothesis that structural variables related to old-growth features affect the distribution of Lobaria pulmonaria in a Mediterranean National Park of Italy. A total of 36 plots, with old-growth characteristics and representing overall three forest types (beech- oak- and mixed- forests) were studied. The lichen was absent in about half of the sites, suggesting that the selection of old-growth forests based solely on structural features is not sufficient to predict the presence of this species, which therefore proves to be rather sensitive and selective. Its abundance was related to high tree circumference and basal area, and to availability of deadwood, confirming the relevant effect of substrate and stand continuity in the conservation of this species and emphasizing its role of indicator species of undisturbed forest ecosystems with long ecological continuity.
The aims of this paper were (i) to define how contrasting land uses affected plant biodiversity in Mediterranean agro-silvo-pastoral-systems across a gradient of disturbance regimes: cork oak forests, secondary grasslands, hay crops, grass covered vineyards, tilled vineyards; (ii) to determine whether these patterns mirrored those of below-ground microorganisms and whether the components of γ-diversity followed a similar model. The disturbance regimes affected plant assemblage composition. Species richness decreased with increasing land use intensity, the Shannon index showed the highest values in grasslands and hay crops. Plant assemblage composition patterns mirrored those of Basidiomycota and Ascomycota. Richness in Basidiomycota, denitrifying bacteria and microbial biomass showed the same trend as that observed for vascular plant richness. The Shannon index pattern of below-ground microorganisms was different from that of plants. The plant γ-diversity component model weakly mirrored those of Ascomycota. Patchy diversity patterns suggest that the maintenance of contrasting land uses associated with different productions typical of agro-silvo-pastoral-systems can guarantee the conservation of biodiversity.
Aim
Our aims were to determine whether cross‐taxon congruence of species composition patterns varies across regions and human disturbance levels and to infer whether these patterns relate to the size of the regional species pool and the sorting of species along a gradient of human disturbance.
Location
Alberta's Boreal and Grassland Natural Regions, Canada.
Method
We compiled presence–absence data of four biological groups (birds, vascular plants, bryophytes and mites) from low and high disturbance sites in upland habitat. The cross‐taxon congruence across ecoregion and disturbance levels was analysed using Mantel and Procrustes tests. We applied resampling without replacement to generate confidence intervals to test for significant differences in strength of congruency between disturbance levels and ecoregions. We performed indicator species analysis to highlight how the species‐level response to high and low disturbance influences the pattern in community‐level cross‐taxon congruence.
Results
Cross‐taxon congruence was stronger when all sites were considered than when high and low disturbance sites were considered separately. Congruency was relatively stronger in high than low disturbance sites in the Boreal ecoregion, but the pattern was reversed in the Grassland ecoregion. More species were indicators of undisturbed habitat than of highly disturbed habitats for all biological groups except for birds. Overall, biological groups that were poorly represented in a region and/or with few characteristic indicator species showed weak congruence in those sites.
Main conclusions
We conclude that a longer disturbance gradient can promote cross‐taxon congruence by increasing the species pool characteristic of low or high disturbance levels. Moreover, regional context can influence (or even reverse) the relative strength of cross‐taxon congruence in high and low disturbance sites, which may explain the inconsistent strength of cross‐taxon congruence along the disturbance gradient. To use biodiversity surrogates across biogeographical regions, it is therefore important to account for the regional and disturbance‐level dependence of cross‐taxon congruence.
Question: What are the edge effect responses of epiphytic lichen communities in Mediterranean Quercus pyrenaica forest?
Location: Central Spain.
Methods: We established ten transects perpendicular to a road dissecting a well conserved remnant of Q. pyrenaica forest into two sections. Transects extended from the forest/road edge to 100 m into the forest. Data were collected from seven plots in each transect at different distances from the edge. Variables were grouped into stand scale variables (distance to edge, number of trees per plot, mean diameter per plot, irradiance) and tree scale variables (diameter and height of sampled trees, aspect of the sampled square and relative height of the square). We used General Mixed Linear Models and constrained ordination techniques to test the hypothesis that the spatio-temporal heterogeneity of light and water controls the occurrence of lichens and bryophytes along the edge-interior gradient in the Q. pyrenaica forest.
Results: Microclimatic parameters vary in a non-linear way; edge and interior stands showed the most divergent and extreme values. Although the micro-environment within Mediterranean forests is heterogeneous, interior conditions are apparently suitable for the performance of some specific forest epiphytes. Consequently, species richness does not show significant differences along the gradient. Total epiphytic cover increases towards the forest interior, but distance to the edge together with other predictors at the tree scale (aspect and height of the square) are the most relevant predictors for the composition and structure of these communities.
Conclusions: Composition and structure of epiphytic communities in a Mediterranean semi-deciduous forest are affected by the edge between the forest and the road constructed. Since some extremely rare lichens only occur at interior stands, the conservation of these threatened elements requires urgent conservation measures because well preserved and unmanaged forests in the Mediterranean region are very rare.
Since 2003 the MCPFE-Forest Europe process has adopted a set of Pan-European Indicators that has become a policy instrument to monitor, evaluate and report progress towards sustainable forest management (SFM). Two new experimental tools have been introduced in the framework of the «State of Forests and Sustainable Forest Management in Europe 2011»: (i) pilot reporting by 14 classes of European Forest Types (EFTs) for a selection of quantitative SFM indicators; (ii) key parameters for monitoring progress for all quantitative indicators.
The objective of this study was to clarify the taxon surrogacy hypothesis relative to vascular plants and bryophytes. A literature review was conducted to obtain papers that met the following criteria: (i) they examined species richness values; or (ii) they evaluated the species richness within the same study sites, or under the same spatial variation conditions. Twenty-seven papers were accessed. The richness of the two taxa, compared in 32 cases, positively co-varied in about half of the comparisons. The response to the spatial variation in environmental or human-induced factors of the two taxa in terms of species richness was rather variable. Based on current knowledge, the main documented findings regard forest habitats and nival gradients. In forest habitats, co-variation in species richness is likely when similar environments are analysed and seems to be strengthened for boreal forests. Along the nival gradient, a different response in terms of richness of the two taxa suggests that vascular plants cannot be considered good surrogates for bryophytes.
Comparing data of epiphytic lichen diversity in semi-natural broad-leaved forests in north-western Germany from the 19th to early 20th centuries with recent inventories revealed strong changes, even though forest structure and tree species composition had changed only little. In three study areas, between 55% and 70% of the species became rarer during the 100–150-year long observation period. In the spatially extended study areas Weser-Ems Lowlands and Solling Mountains, 36% or 39% of the species, respectively, could not be rediscovered in the recent survey. Considering that species might have been overlooked during revisitation, the extinction rate was estimated to be 28% in the Weser-Ems Lowlands and 30% in the Solling Mountains based on a estimated probability for recovering the species of 75% in crustose lichens and 90% in foliose and fruticose lichens. The main causes of the species decline are thought to be forest management (especially the reduction of overmature and decaying trees), the reduction of soil moisture and, with it, air humidity due to drainage as well as the deposition of acidifying and fertilizing substances from the atmosphere. Lichens specialized on rain-sheltered bark furrows and cavities of old trees or smooth, shady bark or moist thick-stemmed deadwood in the forest interior have suffered the strongest declines, including the epiphyte flora of Fagus sylvatica, Central Europe’s most abundant native forest tree species. Only few lichens which benefit from nitrogen deposition, global warming or the acidification of bark due to sulphur dioxide pollution have spread.
Given C samples, with ni observations in the ith sample, a test of the hypothesis that the samples are from the same population may be made by ranking the observations from from 1 to Σni (giving each observation in a group of ties the mean of the ranks tied for), finding the C sums of ranks, and computing a statistic H. Under the stated hypothesis, H is distributed approximately as χ(C – 1), unless the samples are too small, in which case special approximations or exact tables are provided. One of the most important applications of the test is in detecting differences among the population means.** Based in part on research supported by the Office of Naval Research at the Statistical Research Center, University of Chicago.
This review aims at summarizing literature on epiphytic lichens in relation with forest management in temperate deciduous forests of Europe, including suggestions for mitigating the impact of forestry and stimulating further research. The review is focused on environmental factors that directly depend on, or that are known to interact with forest management, such as tree (and forest) age and size, tree species composition, large scale factors (e.g. climate and air pollution), landscape context, and past forest history. The literature demonstrates the sensitiveness of epiphytic lichens to forestry: forest management, and especially the shelterwood system, is a source of threat for many forest-dwelling lichens. Several studies include explicit recommendations for mitigating the effect of forestry. The main ones are: (a) selective cutting should be preferred to the shelterwood system; (b) the negative effect of the shelterwood system could be mitigated by the extension of the rotation period and by the retention of groups of mature trees at the final harvest; (c) the creation of stands with intermediate canopy openness should be promoted; (d) logs and snags should be retained in production forests; (e) large old trees should be maintained in production forests and some of them left until dead and decomposed (“eternity trees”); (f) tree species diversity should be maintained in mixed stands; (g) forest fragments around existing species-rich oldgrowth remnants should be maintained, to create a network of set-aside areas; (h) indicator species could be used for a rapid assessment of forest sites worthy of conservation. However, some topics are still scarcely explored, such as the case of (a) coppice forests, (b) the evaluation of the landscape context and forest history, (c) dead wood-dwelling communities and the role of different types of dead wood for lichen conservation, (d) the effects of emerging infectious diseases, and (e) the use of indicator species to assess the conservation importance of forests. Other research approaches, that are still scarcely developed for lichens, may contribute further information for a more comprehensive understanding of the processes that are behind observed patterns of lichen diversity, such in the case of the evaluation of the role of species functional traits in determining the dispersal ability and the response of lichens to environmental factors.
Epiphytic lichens are one of the taxonomic groups most sensitive to forest management. Nevertheless, they have not yet been exhaustively included in the assessment of Sustainable Forest Management. This work aimed at evaluating the effects of forest management on epiphytic lichens in coppiced forests, exploring the spatial patterns of diversity and the composition of communities. Moreover, the goal was to compare the performance of four potential indicators for monitoring the effects of forest management on epiphytic lichens: total lichen diversity, species associated with intensive management, species associated with aged coppiced woodlands and Indicator Species Ratio (ISR). In humid Mediterranean Liguria, 50 sampling units were chosen in Castanea sativa and deciduous Quercus spp. forests subjected to different forest management practices: intensively managed coppice and aged coppice/high forest. The effect of forest management was evident in terms of species composition, since it was possible to find significantly associated species for each of the two management types. At each sampling site, the four indicators were calculated using Indicator Value Analysis and compared through correspondence analysis. The ISR was shown to be a more effective indicator, being independent of floristic composition and the occurrence of rare species.
Close correlations in species numbers may make it possible to indirectly assess the species richness of difficult taxonomic groups by investigating indicator groups, for which data are more easily collected. We asked if species numbers correlate among the four dominating groups of primary producers in boreal forests (liverworts, macrolichens, mosses, and vascular plants) and if substrate affiliation of species (ground vs. other substrates), sample plot size (0.01–1000 m2), and stand age (young vs. old) influence correlation strength. We used three sets of study plots from northern Sweden each including wide ranges of species richness. Although there are large differences in the ecophysiology and substrate use of vascular plants and the two bryophyte groups (mosses and liverworts), we found strong positive correlations among them not previously reported from boreal forests. In contrast, no correlation in total species richness was found between macrolichens and the two bryophyte groups, despite large overlaps in their ecology. We suggest that the positive correlations among land plants (liverworts, mosses, and vascular plants) are linked to positive relationships between site moisture and species number for all three groups. In contrast, total species number of macrolichens has not been shown to be strongly associated with moisture. However, ground-living lichens and mosses correlated negatively in old forests. This may relate to the inability of macrolichens to exploit shaded and wet old forest ground, a habitat that is used by many moss species. Furthermore, lichens and mosses of ‘other substrates’ correlated positively in old forests, probably because the amount of boulders was positively related to species richness in both groups. Generally, correlations became stronger with increasing plot size, whereas stand age had relatively little influence. We conclude that vascular plants could be used as an indicator group for species richness of mosses and liverworts in boreal landscapes.
Question: What are the edge effect responses of epiphytic lichen communities in Mediterranean Quercus pyrenaica forest? Location: Central Spain. Methods: We established ten transects perpendicular to a road dissecting a well conserved remnant of Q. pyrenaica forest into two sections. Transects extended from the forest/road edge to 100 m into the forest. Data were collected from seven plots in each transect at different distances from the edge. Variables were grouped into stand scale variables (distance to edge, number of trees per plot, mean diameter per plot, irradiance) and tree scale variables (diameter and height of sampled trees, aspect of the sampled square and relative height of the square). We used General Mixed Linear Models and constrained ordination techniques to test the hypothesis that the spatio-temporal heterogeneity of light and water controls the occurrence of lichens and bryophytes along the edge-interior gradient in the Q. pyrenaica forest. Results: Microclimatic parameters vary in a non-linear way; edge and interior stands showed the most divergent and extreme values. Although the micro-environment within Mediterranean forests is heterogeneous, interior conditions are apparently suitable for the performance of some specific forest epiphytes. Consequently, species richness does not show significant dif-ferences along the gradient. Total epiphytic cover increases towards the forest interior, but distance to the edge together with other predictors at the tree scale (aspect and height of the square) are the most relevant predictors for the composition and structure of these communities. Conclusions: Composition and structure of epiphytic com-munities in a Mediterranean semi-deciduous forest are affected by the edge between the forest and the road constructed. Since some extremely rare lichens only occur at interior stands, the conservation of these threatened elements requires urgent conservation measures because well preserved and unmanaged forests in the Mediterranean region are very rare. Nomenclature: Hafellner & Türk (2001); Bisby & Rostov (2005). Abbreviations: GLMM = General Mixed Linear Model; GSF = Global site factor; TVE = Total variation explained.
Question: What are the responses of epiphytic lichens to the intensity of management along a large environmental gradient in Mediterranean Quercus forests?
Location: Central Spain.
Methods: This study was carried out on 4590 trees located in 306 forest stands dominated by Quercus faginea or Quercus ilex ssp. ballota. The effect of forest management and other predictor variables on several species diversity indicators were studied. Variables modelled were total species richness, cyanolichen richness and community composition. A large number of predictor variables were included: forest fragmentation (patch size, stand variability), climate and topographic (altitude, slope, sun radiation, annual rainfall and mean annual temperature) and intensity of management. General linear models and constrained ordination techniques were used to model community traits and species composition, respectively.
Results: Total richness and especially cyanolichens richness were significantly and negatively affected by the intensity of management. Lichen composition was influenced by management intensity, climatic and topographic variables and stand variability.
Conclusions: In Mediterranean forests, human activities related to forestry, agricultural and livestock use cause impoverishment of lichen communities, including the local disappearance of the most demanding species. The conservation of unmanaged forests with a dense canopy is crucial for lichen diversity.
Fungi are a hyperdiverse taxonomic group that may be disappearing at a very high rate. Identifying fungal species is difficult in the field, and the use of highly specialized taxonomists is required. Data and expertise on vascular plants are, on the other hand, much more common and easy to find. We tested the potential of using vascular plants as surrogates to select reserve sites that maximize the pooled number of fungal species. We used data from 25 forest plots in Tuscany, Italy, that were sampled for woody plants, all other plants, and fungi. Species richness of woody plants and all other plants did not correlate with species richness of fungi. The gradients in species composition were similar among the three considered groups, as indicated by a detrended correspondence analysis ordination and species complementarity between pairs of plots. Fungal communities of the 25 plots had a lower β diversity than plant communities, and there were no pairs of totally complementary sites. Site prioritization for conservation was obtained through integer linear programming to find for any given number of sites those combinations containing the maximum pooled species richness of woody plants or all plants. The combinations of sites obtained by optimizing vascular plant species did not maximize the pooled species richness of fungi, whereas those obtained by maximizing woody plant species provided better results for sets of four to eight plots, but not for all the possible combinations. These results indicated that, in general, vascular plants cannot be used to maximize fungal species richness.
Aims Both human and non-human determinants have shaped Mediterranean forest structure over the last few millennia. The effects of recent human activities on forest composition, however, remain poorly understood. We quantified changes in forest composition during the past century in the mixed forests of Quercus suber (cork oak) and Q. canariensis (Algerian oak), and explored the effects of forest management and environmental (climate, topography) factors on forest structure at various spatial and temporal scales.