Quercus Pyrenaica Willd Research Articles

Effects of Boom-Corridor and Selective Thinnings on Harvester Productivity in Dense Small Diameter Pyrenean Oak (Quercus pyrenaica Willd.) Coppices in Spain

Due to socioeconomic transformations in the 20th century, Quercus pyrenaica Willd. coppices in Spain, as well as other European coppices, have experimented an abandonment and lack of intervention leading to stagnant high density stands with fragile health due to competition. Thinnings are often required to ensure their stability and health, producing forest products such as firewood or biomass, which are key energy sources in a carbon-neutral economy. However, thinnings are seldom performed because they lack economic sustainability due to a low productivity, high costs and low biomass prices. In this study, two thinning methods, selective thinning (ST) and boom-corridor thinning (BCT), were tested carrying out a time study in a high-density small-diameter Q. pyrenaica stand in the León province (Castilla y León, Spain) with a forest harvester base machine, on which an accumulating felling head Bracke C16c was mounted. The residual stands were significantly different regarding the final density (greater in BCT) and the final average DBH (bigger in ST), while thinning intensity (odt·ha-1) was the same. In most work elements, time per tree was not significantly different. BCT showed a significant 48.6% increase in harvester productivity when compared to ST, with averaging 4.43 and 2.99 odt·pmh-1, respectively, due mainly to the average weight per extracted tree, 42% greater in BCT. When considering the common range of unit tree weight, the productivity was 16–23% greater for BCT, far less than observed in the trials. These results show the potential of BCT over ST in the studied conditions, although there is room for improvement. Further studies could include the future evolution of the treated stands and perform a cost analysis.

Improvement Cuttings in the Conversion of Pyrenean Oak (Quercus pyrenaica Willd.) Coppice

An appropriate management and valuation of Pyrenean oak (Quercus pyrenaica Willd.) forests are essential in order to ensure their multiple functions and uses. Many coppice forests of Pyrenean oak have been converted into high forests mostly due to changing demands. This work presents a 20-year study conducted with Pyrenean oak coppices, providing results from an experimental trial where silvicultural improvement interventions for coppice conversion were applied. In addition to control, selective thinning and 3-strip thinning with 2 × 2 m, 3 × 3 m, and 3 × 6 m (the latter also included selective thinning) were examined. The study analyzed tree growth, vertical stratification dynamics, and epicormic branching. It was found that the silvicultural interventions promoted tree development differently according to social crown class. The results have shown a significantly different response in tree diameter growth and live crown length, while height growth has been less accentuated. The study also examined the temporal effect of the interventions on diameter growth. Changes in tree crown position and structural characteristics varied among the cutting interventions. Regarding epicormic branching, the results have revealed that the number of shoots does not differ significantly among the treatments but shows differences in length. Management issues regarding Pyrenean oak coppice conversion have also been addressed.

Fagus sylvatica and Quercus pyrenaica: Two neighbors with few things in common

BackgroundThe Iberian Peninsula comprises one of the largest boundaries between Mediterranean and Eurosiberian vegetation, known as sub-Mediterranean zone. This ecotone hosts many unique plant species and communities and constitutes the low-latitude (warm) margin of numerous central European species which co-occur with Mediterranean vegetation. Two of the main species found in this region are the Eurosiberian European beech (Fagus sylvatica L.) and the Mediterranean Pyrenean oak (Quercus pyrenaica Willd.). It remains unclear how the different physiological and adaptive strategies of these two species reflect their niche partitioning within a sub-Mediterranean community and to what extent phenotypic variation (intraspecific variability) is driving niche partitioning across Eurosiberian and Mediterranean species. MethodsWe quantified functional niche partitioning, based on the n-dimensional hypervolume to nine traits related to resource acquisition strategies (leaf, stem and root) plus relative growth rate as an additional whole-plant trait, and the environmental niche similarity between Pyrenean oak and European beech. Further, we analyzed the degree of phenotypic variation of both target species and its relationship with relative growth rates (RGR) and environmental conditions. Plant recruitment was measured for both target species as a proxy for the average fitness. ResultsSpecies’ functional space was highly segregated (13.09% overlap), mainly due to differences in niche breadth (59.7%) rather than niche replacement (25.6%), and beech showed higher trait variability, i.e., had larger functional space. However, both species shared the environmental space, i.e., environmental niches were overlapped. Most plant traits were not related to abiotic variables or RGR, neither did RGR to plant traits. ConclusionsBoth target species share similar environmental space, however, show notably different functional resource-use strategies, promoting a high complementarity that contributes to maintaining a high functionality in sub-Mediterranean ecosystems. Therefore, we propose that conservation efforts be oriented to preserve both species in these habitats to maximize ecosystem functionality and resilience.

Serra de São Mamede Natural Park, a macrofungal diversity hotspot in the Mediterranean region

The Serra de São Mamede Natural Park is a biodiversity hotspot in the broad region of Alentejo, Portugal, where the influence of the Atlantic Ocean allows for the continuity of a Eurosiberian-like forest in the heart of a Mediterranean region. The park is therefore unique among the few protected areas in Portugal. We attempt to describe the macrofungal diversity of the park for the first time. Our results reveal a rich and diverse assembly of macrofungal species (239 taxa), and in particular, mycorrhizal species (145 taxa). Furthermore, 26 taxa are newly recorded from Portugal, while 81 taxa are newly recorded from Alto Alentejo Province. Also, the majority of these newly reported taxa were recorded in mixed stands of Quercus pyrenaica Willd.—a European protected habitat of limited extent—whose importance is enhanced now the rich and diverse associated macrofungal community, as shown in our study.

Root Growth Dynamics and Structure in Seedlings of Four Shade Tolerant Mediterranean Species Grown under Moderate and Low Light

Specific functional traits such as shade tolerance or leaf habits can enhance root growth dynamics and structure of planted seedlings in the understory of planted forests. We assessed how low and moderate light levels (17 and 33% of full sunlight, mimicking after-thinning stocking) affect the root growth dynamics and structure of four late successional trees, three deciduous (Acer monspessulanum L., Quercus pyrenaica Willd and Sorbus torminalis (L.) Crantz) and one evergreen (Quercus ilex L.) species. Rooting depth, dynamics and structure were mainly explained by species functional differences. Roots of deciduous trees elongated faster and deeper and were larger than the roots of the evergreen Q. ilex. Among deciduous trees, S. torminalis had the lowest root growth. Specific leaf area and nutrient concentration were positively related to root growth, highlighting the importance of traits related to the plant economic spectrum, as determinants of species root growth differences. Moderate light level slightly enhanced root growth and decreased the specific leaf area (SLA). Species differences in water potential under drought were positively related to rooting depth, evidencing the importance of its role in overcoming drought stress during seedling establishment. These findings can guide the selection of late successional, shade tolerant tree species for underplanting thinned Mediterranean plantations and provide insights into their ecology.

Impact of successive spring frosts on leaf phenology and radial growth in three deciduous tree species with contrasting climate requirements in central Spain.

Rear-edge tree populations forming the equatorward limit of distribution of temperate species are assumed to be more adapted to climate variability than central (core) populations. However, climate is expected to become more variable and the frequency of climate extremes is forecasted to increase. Climatic extreme events such as heat waves, dry spells and spring frosts could become more frequent, and negatively impact and jeopardize rear-edge stands. To evaluate these ideas, we analyzed the growth response of trees to successive spring frosts in a mixed forest, where two temperate deciduous species, Fagus sylvatica L. (European beech) and Quercus petraea (Matt.) Liebl. (sessile oak), both at their southernmost edge, coexist with the Mediterranean Quercus pyrenaica Willd. (Pyrenean oak). Growth reductions in spring-frost years ranked across species as F. sylvatica > Q. petraea > Q. pyrenaica. Leaf flushing occurred earlier in F. sylvatica and later in Q. pyrenaica, suggesting that leaf phenology was a strong determinant of spring frost damage and stem growth reduction. The frost impact depended on prior climate conditions, since warmer days prior to frost occurrence predisposed to frost damage. Autumn Normalized Difference Vegetation Index data showed delayed leaf senescence in spring-frost years and subsequent years as compared with pre-frost years. In the studied forest, the negative impact of spring frosts on Q. petraea and especially on F. sylvatica growth, was considerably higher than the impacts due to drought. The succession of four spring frosts in the last two decades determined a trend of decreasing resistance of radial growth to frosts in F. sylvatica. The increased frequency of spring frosts might prevent the expansion and persistence of F. sylvatica in this rear-edge Mediterranean population.

The Effects of Native Shrub, Fencing, and Acorn Size on the Emergence of Contrasting Co-Occurring Oak in Mediterranean Grazed Areas

Research Highlights: The regeneration of Quercus species is usually very difficult in many oak woodlands transformed by livestock farming. Some studies have reported that shrubs can facilitate regeneration. However, the strength of interaction may vary depending on, among other factors, the shrub species and the stress tolerance of the oak species. Moreover, further studies are necessary to clarify the relative importance of the two facilitation mechanisms in the same community. Background and Objectives: Cytisus multiflorus (L’Her.) Sweet is a predominant shrub species in the Mediterranean grazed open-oak-woodlands found in the central west of the Iberian Peninsula (bioclimatic limit) and is present with Quercus pyrenaica Willd and Quercus ilex subsp. ballota Samp trees. Thus, we assessed the effect of these native shrubs and acorn size, and the effect of excluding large herbivores, on the seedling emergence of two contrasting co-occurring Quercus species under a bioclimatic limit. Materials and Methods: A manipulative field experiment was carried out considering four treatments as a combination of shrubs (shrub/no-shrub) and fence (fenced/open) factors. A total of twenty plots, five replicates for each treatment were available. In each plot, 20 acorns were sown: 10 acorns (5 small and 5 large) for each Quercus species. Acorn emergence was recorded during the first four years following the sowing. Results: Seedling emergence took place mostly in the spring of the first year after sowing. The presence of shrub was the main significant factor and incremented the emergence of both Q. ilex and Q. pyrenaica. The effect of the fence depended on the Quercus species considered, improving only the emergence of Q. pyrenaica. A negative effect with the small acorns was detected but only for Q. pyrenaica. In all treatments, Q. ilex emerged more than Q. pyrenaica. Conclusions: C. multiflorus had a clear facilitative effect on the seedling emergence of Q. ilex and Q. pyrenaica, which was much greater than the physical effect that acorn size and excluding large herbivores had. As such, this native shrub may have a key role in oak regeneration in Mediterranean grazed areas. Furthermore, in these areas of contact between marcescent and sclerophyllous Quercus species, Q. ilex currently emerges more than Q. pyrenaica. This could be indicative of a shift towards more xeric climatic conditions, which could lead to a change in the dominant tree species in the future. However, this change could be modulated by the effects of native shrub and large herbivores.

Are pine-oak mixed stands in Mediterranean mountains more resilient to drought than their monospecific counterparts?

Climate change projections point to an increase in the intensity and frequency of extreme drought events with important negative impacts on forest functioning. Predicting these impacts constitutes a crucial challenge for forest managers and for the maintenance of ecosystem services supply. Promoting mixed stands seems a promising strategy for adapting forest ecosystems to ongoing climate change. However, some uncertainty exists regarding whether admixture can improve growth resilience to extreme drought events. Here, we aim to assess tree growth response to drought in mixed and monospecific stands of Pinus sylvestris L. and Quercus pyrenaica Willd. in central Spain. We built tree-ring chronologies and evaluated tree growth sensitivity to water availability and growth resilience components to extreme droughts using linear mixed models. We found contrasting species- and climate-specific responses to admixture. Q. pyrenaica growth was significantly higher in mixed than in monospecific stands, especially in years without water limitations, while P. sylvestris showed higher growth in mixed stands under dry conditions. However, our results showed a species-specific trade-off between resistance and recovery. While P. sylvestris showed higher resistance but lower recovery to drought events in mixed than monospecific stands, Q. pyrenaica showed higher recovery but lower resistance. This trade-off might explain the absence of admixture effects on species resilience. Our results highlight the importance of considering species-specific responses to water availability and associated trade-offs when evaluating admixture effects on drought vulnerability. Overall, we show a positive effect of admixture on the long-term growth stability in response to average climate conditions, but no effects in short-term resilience capacity to increasingly common extreme dry conditions. Consequently, admixture can promote forest productivity stability but should be carefully considered as a management solution for promoting the resilience of Mediterranean mountain forests to increasing aridity.

Ecological Diversity within Rear-Edge: A Case Study from Mediterranean Quercus pyrenaica Willd.

Understanding the ecology of populations located in the rear edge of their distribution is key to assessing the response of the species to changing environmental conditions. Here, we focus on rear-edge populations of Quercus pyrenaica in Sierra Nevada (southern Iberian Peninsula) to analyze their ecological and floristic diversity. We perform multivariate analyses using high-resolution environmental information and forest inventories to determine how environmental variables differ among oak populations, and to identify population groups based on environmental and floristic composition. We find that water availability is a key variable in explaining the distribution of Q. pyrenaica and the floristic diversity of their accompanying communities within its rear edge. Three cluster of oak populations were identified based on environmental variables. We found differences among these clusters regarding plant diversity, but not for forest attributes. A remarkable match between the populations clustering derived from analysis of environmental variables and the ordination of the populations according to species composition was found. The diversity of ecological behaviors for Q. pyrenaica populations in this rear edge are consistent with the high genetic diversity shown by populations of this oak in the Sierra Nevada. The identification of differences between oak populations within the rear-edge with respect to environmental variables can aid with planning the forest management and restoration actions, particularly considering the importance of some environmental factors in key ecological aspects.

Differences in stem radial variation between Pinus pinaster Ait. and Quercus pyrenaica Willd. may release inter-specific competition

Species complementarity by morphological and physiological trait differences could cause distinct temporal and spatial use of resources. Accordingly, mixed stands may enhance production, biodiversity and/or provide a better adaptation to future climate conditions. We aim to identify species differences in intra-annual stem radial variation patterns, and to recognize species-specific responses to contrasting weather conditions at key intra-annual growth phases. Stem radial variation was recorded from high temporal resolution point dendrometers (2012–2014) installed on twelve dominant maritime pine and Pyrenean oak trees in two mixed stands in central Spain. Species differences in stem radial variation were analyzed by synchrony statistics, intra-annual pattern modelling, and evaluating the dependence of main intra-annual growth phases on climate conditions. Both species showed important differences on intra-annual radial increment pattern despite general stem radial variation synchrony. Radial increment onset was earlier for maritime pine during the spring and rainy autumns. Species-specific responses to weather indicate that stem radial variation increased with autumn temperature in maritime pine, but decreased in Pyrenean oak trees. However, summer vapor pressure deficit may reduce stem radial variation for maritime pine. Therefore, maritime pine would adapt more efficiently to warmer temperatures associated with climate change, although summer water stress may reduce this competitive bonus.

Specific leaf metabolic changes that underlie adjustment of osmotic potential in response to drought by four Quercus species.

Osmotic adjustment is almost ubiquitous as a mechanism of response to drought in many forest species. Recognized as an important mechanism of increasing turgor under water stress, the metabolic basis for osmotic adjustment has been described in only a few species. We set an experiment with four species of the genus Quercus ranked according to drought tolerance and leaf habit from evergreen to broad-leaved deciduous. A cycle of watering deprivation was imposed on seedlings, resulting in well-watered (WW) and water-stressed (WS) treatments, and their water relations were assessed from pressure-volume curves. Leaf predawn water potential (Ψpd) significantly decreased in WS seedlings, which was followed by a drop in leaf osmotic potential at full turgor (Ψπ100). The lowest values of Ψπ100 followed the ranking of decreasing drought tolerance: Quercus ilex L.<Quercus faginea Lam.<Quercus pyrenaica Willd.<Quercus petraea Matt. Liebl. The leaf osmotic potential at the turgor loss point (ΨTLP) followed the same pattern as Ψπ100 across species and treatments. The pool of carbohydrates, some organic acids and cyclitols were the main osmolytes explaining osmotic potential across species, likewise to the osmotic adjustment assessed from the decrease in leaf Ψπ100 between WW and WS seedlings. Amino acids were very responsive to WS, particularly γ-aminobutyric acid in Q. pyrenaica, but made a relatively minor contribution to osmotic potential compared with other groups of compounds. In contrast, the cyclitol proto-quercitol made a prominent contribution to the changes in osmotic potential regardless of watering treatment or species. However, different metabolites, such as quinic acid, played a more important role in osmotic adjustment in Q. ilex, distinguishing it from the other species studied. In conclusion, while osmotic adjustment was present in all four Quercus species, the molecular processes underpinning this response differed according to their phylogenetic history and specific ecology.

Influence of climate and thinning on Quercus pyrenaica Willd. coppices growth dynamics

Many oak stands (Quercus spp.) have been managed as coppices for firewood production for centuries in the Mediterranean area. After the abandonment of firewood production during the 1980s, current management practices attempt to convert coppices into coppices-with-standards through thinning and promoting forest regeneration via sexual reproduction. In this work, we used long-term data from repeated forest inventories and dendrometers in a thinning trial to assess the effects of thinning and climate on the intra- and inter-annual growth dynamics of Quercus pyrenaica Willd. coppices. Our results revealed that thinning favored the growth of Q. pyrenaica trees, especially when the stand density reduction was high (ca. 50% of the basal area extracted). Unthinned plots displayed more natural mortality i.e., self-thinning. Growth was enhanced with low vapor pressure deficit. Intense thinning treatments displayed higher intra-annual growth rates and interacted positively with rainfall to induce higher growth. We conclude that thinning, especially intensive thinning, may alleviate the negative effects of dry years and thus could provide a potential measure to adapt these stands to the different climatic scenarios with higher temperatures and less precipitation within the framework of sustainable forest management.

Leaf ecophysiological and metabolic response in Quercus pyrenaica Willd seedlings to moderate drought under enriched CO2 atmosphere

Impact of drought under enriched CO2 atmosphere on ecophysiological and leaf metabolic response of the sub-mediterranean Q. pyrenaica oak was studied. Seedlings growing in climate chamber were submitted to moderate drought (WS) and well-watered (WW) under ambient ([CO2]amb =400 ppm) or CO2 enriched atmosphere ([CO2]enr =800 ppm). The moderate drought endured by seedlings brought about a decrease in leaf gas exchange. However, net photosynthesis (Anet) was highly stimulated for plants at [CO2]enr. There was a decrease of the stomatal conductance to water vapour (gwv) in response to drought, and a subtle trend to be lower under [CO2]enr. The consequence of these changes was an important increase in the intrinsic leaf water use efficiency (WUEi). The electron transport rate (ETR) was almost a 20 percent higher in plants at [CO2]enr regardless drought endured by seedlings. The ETR/Anet was lower under [CO2]enr, pointing to a high capacity to maintain sinks for the uptake of extra carbon in the atmosphere. Impact of drought on the leaf metabolome, as a whole, was more evident than that from [CO2] enrichment of the atmosphere. Changes in pool of non-structural carbohydrates were observed mainly as a consequence of water deficit including increases of fructose, glucose, and proto-quercitol. Most of the metabolites affected by drought back up to levels of non-stressed seedlings after rewetting (recovery phase). It can be concluded that carbon uptake was stimulated by [CO2]enr, even under the stomatal closure that accompanied moderate drought. In the last, there was a positive effect in intrinsic water use efficiency (WUEi), which was much more improved under [CO2]enr. Leaf metabolome was little responsible and some few metabolites changed mainly in response to drought, with little differences between [CO2] growth conditions.

Contribution to Trees Health Assessment Using Infrared Thermography

Trees are essential natural resources for ecosystem balance, regional development, and urban greening. Preserving trees has become a crucial challenge for society. It is common for the use of invasive or even destructive techniques for health diagnosis of these living structures, and interventions after visual inspection. Therefore, the dissemination and implementation of increasingly less aggressive techniques for inspection, analysis and monitoring techniques are essential. The latest high-definition thermal cameras record thermal images of high resolution and sensitivity. Infrared thermography (IRT) is a promising technique for the inspection of trees because the tissue of the sap is practically on the surface of the living structure. The thermograms allow the identification of deteriorated tissues and to differentiate them from healthy tissues, and make an observation of the tree as a functional whole body. The aim of this study is to present, based on differences in the temperatures field given by the thermal images, a qualitative analysis of the status of two different arboreal species, Quercus pyrenaica Willd and Olea europaea L. The results show the IRT as an expeditious, non-invasive and promising technique for tree inspection, providing results that are not possible to reach by other methods and much less by a visual inspection. The work represents a contribution to make IRT a tree decision-making tool on the health status of trees.

Ypsolopha rhinolophi sp. nov. (Lepidoptera: Ypsolophidae), a new species from Portugal and France unveiled by bats.

A new species Ypsolopha rhinolophi Corley is described from northern Portugal and south-east France. It resembles Y. alpella (Denis Schiffermüller, 1775) and Y. lucella (Fabricius, 1775) but shows clear differences from both species in DNA barcode and in male and female genitalia. Male genitalia of Y. lucella are illustrated for the first time. The new species has been collected at light, reared from larvae on Quercus pyrenaica Willd. and recognised from DNA barcode fragments obtained from droppings of horseshoe bats.

Multi‐variable approach pinpoints origin of oak wood with higher precision

AbstractAimSpatial variations of environmental conditions translate into biogeographical patterns of tree growth. This fact is used to identify the origin of timber by means of dendroprovenancing. Yet, dendroprovenancing attempts are commonly only based on ring‐width measurements, and largely neglect additional tree–ring variables. We explore the potential of using wood anatomy as a dendroprovenancing tool, and investigate whether it increases the precision of identifying the origin of oak wood. Since different tree–ring variables hold different information on environmental conditions prevailing at specific times of the growing season—which vary between source regions—we hypothesize that their inclusion allows more precise dendroprovenancing.LocationEurope, Spain.TaxonQuercus robur L., Quercus petraea (Matt.) Liebl., Quercus faginea Lam., Quercus pyrenaica Willd.MethodsWe sampled four oak species across Northern Spain, i.e. from the Basque country and Cantabria and—in the Basque country—from low to high elevation (topographic/latitudinal gradient). We measured multiple tree–ring variables to (a) extract complementary variables; (b) present statistical relations among them; (c) analyse region‐specific variation in their patterns based on time–series of individual trees; and (d) determine underlying climate–growth relationships. Leave‐one‐out analysis was used to test whether a combination of selected variables allowed dendroprovenancing of a randomly selected tree within the area.ResultsA combination of latewood width (LW) and earlywood vessel size was used to pinpoint the origin of oak wood with higher precision than ring width or LW only. Variation in LW pinpointed the wood to east and west areas, whereas variation in vessels assigned wood to locations along a latitudinal/topographic gradient. The climatic triggers behind these gradients are respectively an east–west gradient in June–July temperature and a north–south gradient in winter/spring temperatures. The leave‐one‐out analyses supported the robustness of these results.Main conclusionsIntegration of multiple wood–xylem anatomical variables analysed with multivariate techniques leads to higher precision in the dendroprovenancing of ring‐porous oak species.

Physicochemical Properties and Pollen Profile of Oak Honeydew and Evergreen Oak Honeydew Honeys from Spain: A Comparative Study.

This work investigates the similarities and differences of oak honeydew (Quercus pyrenaica Willd.) and evergreen honeydew (Quercus ilex L.) honey produced in Spain. For this purpose, the physicochemical characteristics of 17 samples from oak honeydew and 11 samples from evergreen honeydew collected in different geographical regions were analyzed. All the samples accomplished European Union requirements for honey consumption. Both honey types had amber dark color; however, the evergreen oak honey was clearer than oak honey, having higher mean values in a* and b* coordinates of CIELab scale. In general, both honey types exhibited high electrical conductivity, a moderate value of pH, medium to low water content, and high diastase activity. The reducing sugar content was significantly lower and maltose content was significantly higher in evergreen honeydew. In addition, total phenols and total flavonoid contents, the antioxidant activity and the melissopalynological analysis was performed. The oak honeydew honey had a higher abundance of Castanea, Rubus and Erica pollen grains, while the evergreen oak honeydew honey had a higher abundance of Lavandula, Olea europaea or Anthyllis cytisoides. A multivariate analysis using the most representative pollen types and physicochemical components facilitated the differentiation of the honey samples, thus this information can be useful for the honey characterization.

Metabarcoding reveals that rhizospheric microbiota of Quercus pyrenaica is composed by a relatively small number of bacterial taxa highly abundant

Melojo oak (Quercus pyrenaica Willd.) is a key tree species of Mediterranean forests; however, these forests show an advanced stage of deterioration in the Iberian Peninsula. Plant-associated microorganisms play an essential role improving their host’s fitness, hence, a better understanding of oak rhizospheric microbiome, especially of those active members, could be the first step towards microbiome-based approaches for oak-forest improvement. Here we reported, for the first time, the diversity of total (DNA-based) and potentially active (RNA-based) bacterial communities of different melojo-oak forest formations through pyrosequencing of 16S rRNA gene amplicons. We found that potentially active bacterial communities were as rich and diverse as total bacterial communities, but different in terms of relative abundance patterns in some of the studied areas. Both core microbiomes were dominated by a relatively small percentage of OTUs, most of which showed positive correlation between both libraries. However, the uncoupling between abundance (rDNA) and potential activity (rRNA) for some taxa suggests that the most abundant taxa are not always the most active, and that low-abundance OTUs may have a strong influence on oak’s rhizospheric ecology. Thus, measurement of rRNA:rDNA ratio could be helpful in identifying major players for the development of bacterial bioinoculants.

Biodiversity conservation effectiveness provided by a protection status in temperate forest commons of north Spain

The establishment and maintenance of protected areas is the backbone of global conservation strategies to halt biodiversity loss. However, despite the more than 200,000 legally designated protected sites worldwide, the rate of species extinction has not decreased, for which some debate the real effectiveness of protected areas to preserve biodiversity. Using data from tropical areas, many studies have attempted to test the effectiveness of protected areas by comparing species richness in protected and neighbouring unprotected sites, without reaching a consensus. Here, we extend this line of research with data from temperate deciduous forests inside and outside Picos de Europa National Park and Biosphere Reserve (N Spain). Specifically we compare data from mixed broadleaved woodlands, beech forests (Fagus sylvatica L.) and Pyrenean oak (Quercus pyrenaica Willd.) forests. We conducted botanical inventories and recorded ecological data from 25 0.2-ha concentric plots distributed in forest commons inside the reserve and from other 25 similar plots established in neighbouring not protected forest commons. Data were used to construct a set of ecological indicators and evaluated using modelling methods. We found no significant differences in species composition between plots in protected and non-protected forest commons, likely due to the similar management criteria applied in both land uses. We found less active management outside the protected area, which helps to maintain stands in a semi-natural state. In contrast, we observed the presence of silvicultural treatments inside the protected area, although these treatments were non-intensive, promoting vegetation composition associated to late-successional ecosystems. We only detected significant differences between plots inside and outside the protected area when relation between species richness was analysed with reference to forest habitat type. Precisely, plots of beech forests inside Picos de Europa were more homogenous than plots outside the protected area, which may indicate that management practices inside the protected area do not favour tree species diversity. Non-intensive silviculture management in beech forests inside Picos de Europa seems to promote the presence of the dominant tree species Fagus sylvatica L., which in the absence of perturbations is characterized by conforming monospecific vegetation communities. Overall, our results do not support the idea that protected areas hold more biodiversity than surrounding forest commons. Conservation treatments applied in protected areas should promote the presence of species associated to disturbances, particularly in stands tending to homogeneous species composition at late-successional stages, as this may enhance their resilience under the current rapid global changes.

New species of Pseudoscorpiones (Arachnida) from tree hollows in a Mediterranean oak forest in Spain.

Pseudoscorpions inhabiting mature Quercus pyrenaica Willd. trees have been surveyed using hollow emergence traps and window traps in Salamanca, Spain. Three new species are described: Neobisium (N.) hispanicum Zaragoza Hernández-Corral, n. sp., Rhacochelifer gaeli Zaragoza Hernández-Corral, n. sp. and Rhacochelifer nonidezi Zaragoza Hernández-Corral, n. sp. The genera Amblyolpium Simon, 1898 and Beierochelifer Mahnert, 1977 and the species Amblyolpium dollfusi Simon, 1898 and Beierochelifer peloponnesiacus (Beier, 1929) are new records for the Iberian Peninsula. Beierochelifer peloponnesiacus jonicus (Beier, 1932) is shown to be a junior subjective synonym of B. peloponnesiacus n. syn. New regional records of five other species belonging to the families Cheliferidae, Chernetidae and Withiidae are given. Keys are given for the species of the genera Pseudorhacochelifer Beier, 1976 and Rhacochelifer Beier, 1932 with elongated keels on posterolateral corners of carapace and anterior tergites in males, and for the Rhacochelifer species of the Iberian Peninsula. Complementary data to the description of the female syntypes from Caravaca (Murcia, mainland Spain) and males from the Canary Islands of Rhacochelifer pinicola (Nonídez, 1917) are given. Brief redescriptions of the female of Neobisium (N.) maroccanum Beier, 1930 and the male of Rhacochelifer euboicus Mahnert, 1977 are provided. The previous record of R. disjunctus from Slovakia is shown to be an error for R. euboicus. New data on the distribution and habitats of species of Cheliferidae, Chernetidae and Withiidae are given.