The ongoing range expansion of the invasive oak lace bug across Europe: current occurrence and potential distribution under climate change.

In recent years, the oak lace bug, Corythucha arcuata, has emerged as a significant threat to European oak forests. This species, native to North America, has in the last two decades rapidly extended its range in Europe, raising concerns about its potential impact on the continent's invaluable oak populations. To address this growing concern, we conducted an extensive study to assess the distribution, colonization patterns, and potential ecological niche of the oak lace bug in Europe. We gathered 1792 unique presence coordinates from 21 Eurasian countries, utilizing diverse sources such as research observations, citizen science initiatives, GBIF database, and social media reports. To delineate the realized niche and future distribution, we employed an ensemble species distribution modelling (SDM) framework. Two future greenhouse gas scenarios (RCP 4.5 and RCP 8.5) were considered across three-time intervals (2021-2040, 2061-2080, and 2081-2100) to project and evaluate the species' potential distribution in the future. Our analysis revealed that significant hotspots rich in host species occurrence for this invasive insect remain uninvaded so far, even within its suitable habitat. Furthermore, the native ranges of Turkey oak (Quercus cerris L.) and Hungarian oak (Quercus frainetto L.) species offer entirely suitable environments for the oak lace bug. In contrast, the pedunculate oak and sessile oak distribution ranges currently show only 40 % and 50 % suitability for colonization, respectively. However, our predictive models indicate a significant transformation in the habitat suitability of the oak lace bug, with suitability for these two oak species increasing by up to 90 %. This shift underlines an evolving landscape where the oak lace bug may exploit more of its available habitats than initially expected. It emphasises the pressing need for proactive measures to manage and stop its expanding presence, which may lead to a harmful impact on the oak population across the European landscape.

People's Perception and Awareness towards Plant Invasion, Its Impacts on Forest Ecosystem Services and Livelihood: A Tale of Central Himalayas.

Plant invasion is a leading threat to biodiversity, ecosystem services and human wellbeing worldwide. In the central Himalayas intentionally or accidentally introduced invasive alien plant species (IAPS) facilitate their own establishment and spread, which is altering forest structure, vegetation composition, species diversity and livelihood. To understand the perception and awareness amongst local communities about invasive alien and native plants and its effect on local livelihood, a questionnaire-based study was conducted in 10 villages of Nainital district, Uttarakhand, India. Household data of 179 respondents were triangulated with key informants such as community leaders, teachers and older people. A majority of the respondents were found to be more familiar with the native species (Berberis asiatica, Pyracantha crenulata and Rubus ellipticus) than IAPS (Ageratina adenophora and Lantana camara). Both the IAPS negative impacts on native biodiversity, ecosystem services and livelihood. During the last two decades IAPS have encroached on various forests and caused a decrease in native species in the study area. According to the local perception, deforestation, forest fire, climate change, increased transport, light weight seed, no use and grazing etc. have been the main factors behind the spread of IAPS. A. adenophora invaded both chir pine (Pinus roxburghii) and banj oak (Quercus leucotrichophora) forests while L. camara remained more prominent in low elevation open canopy chir pine forest. Uprooting is the primary method used to control IAPS in crop fields and forests. The studied villages have not reported awareness and education programs about the IAPS. Our study demonstrates the wide range of perspectives on the threat posed by IAPS to forest ecosystems and natural resources. Education could help to raise awareness about the issue and could be beneficial in managing and controlling invasion in the Himalayan region.

Chronic drought alters extractable concentrations of mineral elements in Mediterranean forest soils.

Soil mineral elements play a crucial role in ecosystem productivity and pollution dynamics. Climate models project an increase in drought severity in the Mediterranean Basin in the coming decades, which could lead to changes in the composition and concentrations of mineral elements in soils. These changes can have significant impacts on the fundamental processes of plant-soil cycles. While previous studies have predominantly focused on carbon, nitrogen, and phosphorus, there is a notable lack of research on the biogeochemical responses of other mineral elements to increasing drought. In this study, we investigated the effects of chronic drought (15 years of experimental rainfall exclusion) and seasonal drought (summer period) on the extractable soil concentrations of 17 mineral elements (arsenic (As), calcium (Ca), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), potassium (K), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), sulphur (S), strontium (Sr), vanadium (V) and zinc (Zn)) in a Mediterranean holm oak forest. We also explored the potential biotic and abiotic mechanisms underlying the changes in extractable elemental concentrations under chronic drought conditions. Our findings reveal that soil elemental concentrations varied significantly due to seasonal changes and chronic drought, with soil microclimate, biological activity, and organic matter being the main drivers of this variability. Levels of soil water content primarily explained the observed variations in soil elemental concentrations. Most of the mineral elements (13 out of 17) exhibited higher concentrations during winter-spring (wet seasons) compared to summer-autumn (dry seasons). The chronic drought treatment resulted in K limitation, increasing vegetation vulnerability to drought stress. Conversely, the accumulation of S in soils due to drought may intensify the risk of S losses from the plant-soil system. Under drought conditions, certain trace elements (particularly Mn, V, and Cd) exhibited increased extractability, posing potential risks to plant health and the exportation of these elements into continental waters. Overall, our results suggest that alterations in mineral element concentrations under future drier conditions could promote ecosystem degradation and pollution dispersion in the Mediterranean Basin. Understanding and predicting these changes are essential for effective ecosystem management and mitigating the potential negative impacts on plant health and water quality.

Long-term trends and influence of climate and land-use changes on pollen profiles of a Mediterranean oak forest.

Climate change is disrupting phenology and interaction patterns of natural ecosystems, but also human activities that modify land-uses have a direct impact, especially on species distribution and loss of biodiversity. The objective of this study is to evaluate the impact of climate and land-use changes on phenology and airborne pollen spectrum in a Mediterranean natural area, dominated by Quercus Forest and 'dehesa', in the South of the Iberian Peninsula. 61 different pollen types were identified over a 23-year period (1998-2020), mainly from trees and shrubs, such as Quercus, Olea, Pinus or Pistacia, and from herbaceous plants, such as Poaceae, Plantago, Urticaceae or Rumex. A comparison of pollen data from the first years of the study (1998-2002) up recent years (2016-2020), showed a substantial decrease in the relative abundance of pollen from autochthonous species associated with natural areas, such as Quercus or Plantago. However, the relative abundance of the pollen from cultivated ones such as Olea and Pinus, which is used for reforestation has increased. Regarding flowering phenology trends, our analyses revealed variations between -1.5 and 1.5 days per year. Taxa showing an advance phenology were Olea, Poaceae and Urticaceae, whereas Quercus, Pinus, Plantago, Pistacia or Cyperaceae experienced delayed pollination. Meteorological trends in the area generally resulted in an increase in both minimum and maximum temperatures, along with a decrease in precipitations. Changes in pollen concentration and phenology were correlated with changes in air temperatures and precipitation, although the positive or negative influence varied for each pollen type. The results suggest that climate change together with those motivated by land cover changes lead by human activities are having an impact on the phenology and pollen concentration, with the related consequences on pollination and therefore biodiversity more concerning in threatened areas as the Mediterranean Basin.

Trait-mediated responses of caterpillar communities to spongy moth outbreaks and subsequent tebufenozide treatments.

Outbreaks of the spongy moth Lymantria dispar can have devastating impacts on forest resources and ecosystems. Lepidoptera-specific insecticides, such as Bacillus thuringiensis var. kurstaki (BTK) and tebufenozide, are often deployed to prevent heavy defoliation of the forest canopy. While it has been suggested that using BTK poses less risk to non-target Lepidoptera than leaving an outbreak untreated, in situ testing of this assumption has been impeded by methodological challenges. The trade-offs between insecticide use and outbreaks have yet to be addressed for tebufenozide, which is believed to have stronger side effects than BTK. We investigated the short-term trade-offs between tebufenozide treatments and no-action strategies for the non-target herbivore community in forest canopies. Over 3 years, Lepidoptera and Symphyta larvae were sampled by canopy fogging in 48 oak stands in southeast Germany during and after a spongy moth outbreak. Half of the sites were treated with tebufenozide and changes in canopy cover were monitored. We contrasted the impacts of tebufenozide and defoliator outbreaks on the abundance, diversity, and functional structure of chewing herbivore communities. Tebufenozide treatments strongly reduced Lepidoptera up to 6 weeks after spraying. Populations gradually converged back to control levels after 2 years. Shelter-building species dominated caterpillar assemblages in treated plots in the post-spray weeks, while flight-dimorphic species were slow to recover and remained underrepresented in treated stands 2 years post-treatment. Spongy moth outbreaks had minor effects on leaf chewer communities. Summer Lepidoptera decreased only when severe defoliation occurred, whereas Symphyta declined 1 year after defoliation. Polyphagous species with only partial host plant overlap with the spongy moth were absent from heavily defoliated sites, suggesting greater sensitivity of generalists to defoliation-induced plant responses. These results demonstrate that both tebufenozide treatments and spongy moth outbreaks alter canopy herbivore communities. Tebufenozide had a stronger and longer lasting impact, but it was restricted to Lepidoptera, whereas the outbreak affected both Lepidoptera and Symphyta. These results are tied to the fact that only half of the outbreak sites experienced severe defoliation. This highlights the limited accuracy of current defoliation forecast methods, which are used as the basis for the decision to spray insecticides.

Tree dieback, woody plant diversity, and ecosystem driven by topography in semi-arid mountain forests: Implication for ecosystem management.

Mountain landscapes are highly heterogeneous due to topography, notably positions along slope and slope shapes, which control ecosystem mechanisms. We hypothesized that tree dieback is controlled by topography, selecting productive and less diverse communities in lower slopes, and stress-resistant and more diverse communities on upper slopes. Understanding how this heterogeneity drives vegetation patterns should provide benchmarks for ecosystem management of mountain forest dominated by Quercus brantii. Woody communities were sampled along convex vs concave topography (i.e., ridge vs talweg), and with measurements of tree dieback severity, environmental variables (litter depth, soil quality, rock outcrop), stand structure (canopy cover, mistletoe infestation, tree diameter and height, diameter and height differentiations, oaks' number from sprout-clumps or seed-origin), and biodiversity. Slope position was the most significant driver that affected all variables, excepted evenness. Dieback severity was higher on slope shoulders and summits, and lower in lower slopes where trees were the most productive: taller, larger, more homogeneous, and mostly seed-origin. Catena shape affected the diversity and dieback severity, both higher in talwegs, but had no effect on environmental variables and little on stand structure. Outputs indicate that the higher diversity of woody plants is on upper slopes supporting stress-resistant community associated with more severe dieback and mistletoe infection probably because frugivore birds attracted by the shrubs' fruits. Semi-arid forest management must consider the shaped-slope ecosystem heterogeneity by preserving ridges that are more susceptible to tree dieback, and naturally support biodiversity. Restoration measures on lower fertile slopes could be carried out by oak planting or seedlings under the cover of shrubs to counter dieback effects and environmental stresses. In addition, forestry measures can be taken in lower positions for the conversion of coppice to high oak forest to potentially consider a moderate forestry.

Scleromatobacter humisilvae gen. nov., sp. nov., a novel bacterium isolated from oak forest soil.

A novel bacterial strain, designated BS-T2-15T, isolated from forest soil in close proximity to decaying oak wood, was characterized using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences as well as phylogenomic analyses based on coding sequences of 340 concatenated core proteins indicated that strain BS-T2-15T forms a distinct and robust lineage in the Rubrivivax-Roseateles -Leptothrix-Azohydromonas -Aquincola-Ideonella branch of the order Burkholderiales. The amino acid identity and the percentage of conserved proteins between the genome of strain BS-T2-15T and genomes of closely related type strains ranged from 64.27 to 66.57% and from 40.89 to 49.27 %, respectively, providing genomic evidence that strain BS-T2-15T represents a new genus. Its cells are Gram-stain-negative, aerobic, motile by a polar flagellum, rod-shaped and form incrusted white to ivory colonies. Optimal growth is observed at 20-22 °C, pH 6 and 0% NaCl. The predominant fatty acids of strain BS-T2-15T are C16 : 1 ω7c, C16 : 0 and C14 : 0 2-OH. Its polar lipid profile consists of a mixture of phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol and its main respiratory quinone is ubiquinone 8. The estimated size of its genome is 6.28 Mb with a DNA G+C content of 69.56 mol%. Therefore, on the basis of phenotypic and genotypic properties, the new strain BS-T2-15T represents a novel genus and species for which the name Scleromatobacter humisilvae gen. nov., sp. nov., is proposed. The type strain is BS-T2-15T (DSM 113115T=UBOCC-M-3373T).

Detecting patterns of post-fire pine regeneration in a Madrean Sky Island with field surveys and remote sensing.

The American Southwest is experiencing drastic increases in aridity and wildfire incidence, triggering conversion of some frequent surface forests to non-forest. Extensive research has focused on these dynamics in regional ponderosa pine forests, but we know much less about Madrean pine-oak forests, which are broadly distributed from the Sierra Madre in Mexico to the Sky Island mountain ranges in the U.S. Increased fire incidence and drought in these forests are limiting pine regeneration and driving conversion of biodiverse forests to oak shrublands. We investigated regeneration patterns in Pinus engelmannii and P. leiophylla during severe drought 10 years after the Horseshoe Two Megafire in the Chiricahua Mountains, Arizona-a follow-up to an assessment five years post-fire. In long-term plots, we examined changes in pine seedling and resprout recruitment. Past research demonstrated that topography and fire severity influenced pine recruitment across environmental gradients. We investigated here whether Landsat-8 normalized difference vegetation index (NDVI) and evapotranspiration estimated by the ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) added explanatory value to our understanding of these patterns. Conversion of Madrean pine-oak forest to oak shrublands continued 6-10 years post-fire. A dense, low oak canopy continued to coalesce in sites subject to severe fire. The importance of resprouts in P. leiophylla regeneration accelerated because these plants outgrew competing oak resprouts. Topography and fire severity (dNBR) were important predictors of 2021 patterns of pine recruitment. NDVI added explanatory value to these models, suggesting its potential in tracking forest dynamics. Evapotranspiration did not add value, likely because ECOSTRESS' larger pixel sizes and moving pixel locations created excessive subpixel heterogeneity in this highly dissected landscape. These models suggest that P. engelmannii is more drought sensitive, was more negatively affected by drought and fire, and is more at risk to shifts in climate and wildfires than P. leiophylla.

Landscape conservation and protected areas (case of Dena, Iran).

Inefficient management of protected areas (PAs) is often due to ignoring their surrounding matrix in the baseline studies, especially in wooded landscapes. In Iran, the application of landscape structure studies in protection policies and PA management is not prevalent. In this study, land cover changes in Dena Rural District (including parts of inside and outside Dena PA) have analyzed using the process of the Landsat images along with field survey two times (1989 and 2018). The landscape structural integrity was quantified based on the situation of oak forest land and its alteration. The composition and the configuration of oak forest land were assessed by metrics based on the moving extent of the Persian squirrel, Sciurus anomalus (which is an endangered focal endemic species completely dependent on the oak forest). Alterations of landscape structural integrity were compared for inside and outside Dena PA and at different altitudes. The results show connectivity loss and increased fragmentation of oak remnant patches, but this deforestation is more severe near areas facing direct human impacts and interventions. These are among attributes that are to be considered for zoning PA (such as controlling zone and training/participation zone). At higher altitudes, physical protection and strict control are more effective, while training local communities for stewardship is more essential at lower altitudes for conserving woodland integrity.

Asymmetric effects between tree and understorey litters on mixed litter decomposition in temperate Quercus variabilis forest.

Litter decomposition is a critical process of biogeochemical cycles of ecosystem. While growing evidences have shown the decomposition rates of litter mixture are different from those of single-species litters, the mutual effects between different functional type species in the mixture remain inconclusive. A field litterbag experiment was conducted to determine the mutual effects of three functional type plants [tree (Quercus variabilis), shrub (Lindera glauca), and herb (Lygodium japonicum)] during the decomposition in a temperate oak forest. After 400 days of in situ incubation, the mass loss rate of each species-specific in the mixture was greater than that decomposed as monoculture, showing the greatest mass loss in the three-species litter mixture. In addition, the decomposition constant for each species was stimulated while mixed with other species. The presence of L. glauca leaf litter significantly elevated total N (15.0%) and C loss (8.92%) of Q. variabilis leaf litter, and the existence of Q. variabilis leaf litter also led to enhanced total N (10.4%) and C (9.1%) release of L. glauca leaf litter. The addition of L. japonicum in the mixed litters showed substantially positive effects on total N (16.5% and 10.8%) and C (10.6% and 14.2%) release of both L. glauca and Q. variabilis litters. In contrast, neither Q. variabilis nor L. glauca litter exhibited effects on the total N and C loss of L. japonicum litter. Our results indicate that the mutual effects between different functional types on nutrient release were asymmetric in the mixed litters. The role of species-specific in the mixture should be highlighted while evaluated the nonadditive effects in the leaf litter mixing experiments.

Species Distribution Pattern and Their Contribution in Plant Community Assembly in Response to Ecological Gradients of the Ecotonal Zone in the Himalayan Region.

The ecotonal zones support populations that are acclimated to changing, fluctuating, and unstable conditions, and as a result, these populations are better equipped to adjust to expected change. In this context, a hypothesis was tested that there must be vegetation dominated by unique indicator plant species under the influence of ecological gradients in the ecotonal zone of Manoor Valley (northwestern Himalaya), Pakistan. Keeping the aforementioned hypothesis in mind, detailed field studies were conducted during different seasons in 2015-18. Line transect sampling and phytosociological characteristics (density, frequency, cover, and their relative values and Importance Value) were implemented as ecological methods. This investigation documented 97 plant species recorded from seven sampling sites. The community distribution modelling revealed that the ecological variables separate the seven sampling sites into two major plant communities (Indigofera-Parrotiopsis-Bistorta and Ziziphus-Leptopus-Quercus) recognized by TWINSPAN. The IBP communities showed a positive and significant correlation with altitude (1789.6-1896.3 m), sandy soil texture with a slightly acidic pH (6.4-6.5), and higher phosphorous (9-13 mg kg-1). In contrast with this, the ZLQ community was recognized on the southern slope under the strong influence of high electrical conductivity (2.82-5.4 dsm-1), organic matter (1.08-1.25%), calcium carbonate (5.8-7.6 mg kg-1), potassium (202-220 mg kg-1), and temperature (28.8-31.8 °C). Hence, both communities were found on opposite axes with clear differences based on the ecological gradients. NMDS clustered different species with similar habitats and different stands with common species, showing that plant species and stands were in a linear combination with ecological gradients. The IPB community has the maximum number of plant species (87 species), Shannon value (H' = 4), Simpson value (0.98), and Pielou's evenness value (0.96). Thus, the multivariate approaches revealed unique vegetation with sharp boundaries between communities which might be due to abrupt environmental changes.

Impact of urbanization on functional diversity in macromycete communities along an urban ecosystem in Southwest Mexico.

Macromycetes are a group of fungi characterized by the production of fruit bodies and are highly relevant in most terrestrial ecosystems as pathogens, mutualists, and organic matter decomposers. Habitat transformation can drastically alter macromycete communities and diminish the contribution of these organisms to ecosystem functioning; however, knowledge on the effect of urbanization on macrofungal communities is scarce. Diversity metrics based on functional traits of macromycete species have shown to be valuable tools to predict how species contribute to ecosystem functionality since traits determine the performance of species in ecosystems. The aim of this study was to assess patterns of species richness, functional diversity, and composition of macrofungi in an urban ecosystem in Southwest Mexico, and to identify microclimatic, environmental, and urban factors related to these patterns in order to infer the effect of urbanization on macromycete communities. We selected four oak forests along an urbanization gradient and established a permanent sampling area of 0.1 ha at each site. Macromycete sampling was carried out every week from June to October 2017. The indices used to measure functional diversity were functional richness (FRic), functional divergence (FDig), and functional evenness (FEve). The metric used to assess variation of macrofungal ecological function along the study area was the functional value. We recorded a total of 134 macromycete species and 223 individuals. Our results indicated a decline of species richness with increased urbanization level related mainly to microclimatic variables, and a high turnover of species composition among study sites, which appears to be related to microclimatic and urbanization variables. FRic decreased with urbanization level, indicating that some of the available resources in the niche space within the most urbanized sites are not being utilized. FDig increased with urbanization, which suggests a high degree of niche differentiation among macromycete species within communities in urbanized areas. FEve did not show notable differences along the urbanization gradient, indicating few variations in the distribution of abundances within the occupied sections of the niche space. Similarly, the functional value was markedly higher in the less urbanized site, suggesting greater performance of functional guilds in that area. Our findings suggest that urbanization has led to a loss of macromycete species and a decrease in functional diversity, causing some sections of the niche space to be hardly occupied and available resources to be under-utilized, which could, to a certain extent, affect ecosystem functioning and stability.

Driving forces for recovery of forest vegetation after harvesting a subalpine oak forest in eastern Tibetan Plateau.

Uncertainty regarding how subalpine forest ecosystems respond to tree harvesting hinders their sustainable management and conservation strategies. To investigate the impact of oak (Quercus aquifolioides Rehd. et Wils.) harvesting and stand recovery processes on soil microbial communities and understory vegetation on the eastern Tibetan Plateau, we sampled and quantified the microbial community structure and understory vegetation in three age classes (1 year, 10 years, and 20 years since tree logging) of harvested stands and an un-harvested reference (control) stand of subalpine oak forest. Our result showed logging significantly altered the edaphic properties (p < 0.001) and shifted microbial community structure (p < 0.05), increasing the abundances of the Actinobacteria and arbuscular mycorrhizal fungi (AMF) but decreasing fungi and general, gram-positive and gram-negative bacteria. Post-harvest evolution increased the biomass of understory vegetation and reshaped its community. Fungi (18:1ω7c, 18:1ω9c) and gram-negative bacteria (18:2ω7c, cy19:0) abundances changed significantly (p < 0.01) after harvesting and during stand recovery, suggesting their potential use as indicators for post-harvest oak recovery. Structural equation modeling (SEqM) revealed that, via litter, residue, and edaphic properties, the recovery process indirectly promoted microbe abundance while the overstory vegetation regrowth inhibited the plant community's biomass in the understory. Microbial communities only had a minor, direct effect on understory vegetation. Litter and edaphic factors played important roles in reshaping understory plant and soil microbial communities for post-harvest evolution.

Bryophyte and lichen biomass and nitrogen fixation in a high elevation cloud forest in Cerro de La Muerte, Costa Rica.

Cloud forests have been found to lose more nitrogen in stream discharge than they gain from atmospheric deposition. They also support a large diversity and biomass of tree epiphytes, predominately composed of cryptogams. Since cryptogam epiphytes harbor nitrogen fixing cyanobacteria, they may help make up for the nitrogen loss from ecosystems. We assessed cryptogam biomass on the ground, boles and branches in Quercus costaricensis dominated stands near the tree line in the Cordillera de Talamanca, Costa Rica. Nitrogen fixation was assayed using 15N2 uptake. Total cryptogam biomass was 2 977 kg ha-1, with 67% being found on the lower branches. Bryophytes and chlorolichens made up 53% and 44%, respectively, of the biomass. Half of the bryophyte mass was composed of the liverwort Plagiochila heterophylla, and 66% of the chlorolichen of Lobariella pallida. There were no significant differences in nitrogen fixation rates between the cryptogam species, with a mean rate of 5.04 µg N g-1 day-1 during the predominantly wet condition in the forest. The overall nitrogen input from fixation was 6.1 kg N ha-1 year-1, of which 78% came from bryophytes, 18% from chlorolichens, and 4% from cyanolichens. Only 2.0% of the fixation occurred in cryptogams on the ground, whereas 67%, 24%, and 7% occurred on the lower branches, boles, and upper branches, respectively. These results show that tree epiphytes constitute a significant source of nitrogen for these forests, due to the trees' large surface area, and can make up for the nitrogen lost from these ecosystems.

Neither ant dominance nor abundance explain ant-plant network structure in Mexican temperate forests.

BACKGROUND: Ant-plant mutualistic networks tend to have a nested structure that contributes to their stability, but the ecological factors that give rise to this structure are not fully understood. Here, we evaluate whether ant abundance and dominance hierarchy determine the structure of the ant-plant networks in two types of vegetation: oak and grassland, in two temperate environments of Mexico: Flor del Bosque State Park (FBSP) and La Malinche National Park (MNP). We predicted that dominant and abundant ant species make up the core, and submissives, the periphery of the network. We also expected a higher specialization level in the ant trophic level than in plant trophic level due to competition among the ant species for the plant-derived resources. METHODS: The ant-plant interaction network was obtained from the frequency of ant-plant interactions. We calculated a dominance hierarchy index for the ants using sampling with baits and evaluated their abundance using pitfall traps. RESULTS: In MNP, the Formica spp. species complex formed the core of the network (in both the oak forest and the grassland), while in FBSP, the core species were Prenolepis imparis (oak forest) and Camponotus rubrithorax (grassland). Although these core species were dominant in their respective sites, they were not necessarily the most dominant ant species. Three of the four networks (oak forest and grassland in FBSP, and oak forest in MNP) were nested and had a higher number of plant species than ant species. Although greater specialization was observed in the ant trophic level in the two sites and vegetations, possibly due to competition with the more dominant ant species, this was not statistically significant. In three of these networks (grassland and oak forest of MNP and oak forest of FBSP), we found no correlation between the dominance hierarchy and abundance of the ant species and their position within the network. However, a positive correlation was found between the nestedness contribution value and ant dominance hierarchy in the grassland of the site FBSP, which could be due to the richer ant-plant network and higher dominance index of this community. CONCLUSIONS: Our evidence suggests that ant abundance and dominance hierarchy have little influence on network structure in temperate ecosystems, probably due to the species-poor ant-plant network and a dominance hierarchy formed only by the presence of dominant and submissive species with no intermediate dominant species between them (absence of gradient in hierarchy) in these ecosystems.

Consequences of Climate Change-Induced Habitat Conversions on Red Wood Ants in a Central European Mountain: A Case Study.

The consequences of anthropogenic climate change are one of the major concerns of conservation biology. A cascade of negative effects is expected to affect various ecosystems, one of which is Central European coniferous forests and their unique biota. These coniferous forests are the primary habitat of many forest specialist species such as red wood ants. Climate change-induced rising of temperature allows trees to skip winter hibernation, making them more vulnerable to storms that cause wind felling, and in turn, promotes bark beetle infestations that results in unscheduled clear-cuttings. Red wood ants can also be exposed to such habitat changes. We investigated the effects of bark beetle-induced clear-cutting and the absence of coniferous trees on colonies of Formica polyctena, including a mixed-coniferous forest as a reference. Our aim was to investigate how these habitat features affect the nest characteristics and nesting habits of F. polyctena. Our results indicate that, in the absence of conifers, F. polyctena tend to use different alternatives for nest material, colony structure, and food sources. However, the vitality of F. polyctena colonies significantly decreased (smaller nest mound volumes). Our study highlights the ecological flexibility of this forest specialist and its potential to survive under extreme conditions.

Modelling functional response of reptiles to fire in two Mediterranean forest types.

Fire is one of the main disturbances to terrestrial environments, transforming habitat structure and affecting community composition. Coupled with fire, forest type and vegetation structure modulate the taxonomic response to fire by ectotherm organisms such as reptiles. The response of each reptile species to fire is based on their functional attributes, which make some species resilient to fire and others vulnerable to that disturbance and only adapted to long-unburnt landscapes. We studied the functional response of a reptile community at 13 burnt sites within the African rim of the Western Mediterranean, and in two contrasting forest types, i.e. native cork oak forests (five sites) and pine plantations (eight sites). We compiled seven functional traits for the reptile species in the study areas, and quantified reptile functional diversity at each sampled plot. Variation in this index was examined from burnt to nearby unburnt plots, both in cork oak and pine forests, with generalized linear mixed models. Redundancy analysis was used to identify which functional traits were associated with particular plot types. We found 2149 individual reptiles from 15 species. The functional response of reptiles to fire was forest-type dependent: functional richness did not change with fire in cork oak forest plots, but increased with fire in the pine plantation ones. High reptile functional richness in cork oak plots was due to high species richness in this forest type. The functional-redundancy analysis showed that cork oak forest hosts a reptile community functionally composed of small Mediterranean ground- and rock-dwelling lizards. In pine plantation plots, however, saxicolous geckos and phytophagous tortoises indicate the availability of other microhabitat and food resources to be exploited by reptile species with different functional traits.

Saproxylic Cetoniidae (Coleoptera: Scarabaeoidea): A 'Females' World' or a Question of Dependence on Deadwood?

We explored the dependence of some Cetoniidae species on saproxylic environments and microhabitats in a Mediterranean oak forest by analyzing species collected using different kinds of traps-log emergence, hollow emergence, and interception traps-and the sex ratio of the species in each trap. Comparing the sex ratio of the species collected via emergence versus interception was useful to unravel the degree of dependence on saproxylic microhabitats. Among the species studied, Cetonia aurataeformis Curti, 1913 (Coleoptera: Cetoniidae) was the only obligate tree hollow inhabitant. Special attention should thus be paid to the maintenance of tree hollows for the species' conservation in Mediterranean forests. A gradient of dependence on tree hollows was established from the more dependent Protaetia (Potosia) cuprea (Fabricius, 1775) (Coleoptera: Cetoniidae) and Protaetia (Potosia) opaca (Fabricius, 1787) (Coleoptera: Cetoniidae) to the less dependent Protaetia (Netocia) morio (Fabricius, 1781) (Coleoptera: Cetoniidae). All the latter species can be considered facultatively dependent, to varying degrees, on tree hollows. By contrast, the saproxylic affinity of Protaetia (Netocia) oblonga (Gory and Percheron, 1833) (Coleoptera: Cetoniidae), Tropinota squalida (Scopoli, 1783) (Coleoptera: Cetoniidae) and Oxythyrea funesta (Poda, 1761) (Coleoptera: Cetoniidae) was doubtful. Generally, the sex ratio of the studied species was female-biased. A possible explanation may be local male competition for females, suggesting the Cetoniinae is a female world. However, the range of difference in the female-biased sex ratio among species suggests it is important to explore other possible causes, such as differences in dispersal abilities.

Site-Specific Microbial Decomposer Communities Do Not Imply Faster Decomposition: Results from a Litter Transplantation Experiment.

Microbes drive leaf litter decomposition, and their communities are adapted to the local vegetation providing that litter. However, whether these local microbial communities confer a significant home-field advantage in litter decomposition remains unclear, with contrasting results being published. Here, we focus on a litter transplantation experiment from oak forests (home site) to two away sites without oak in South Tyrol (Italy). We aimed to produce an in-depth analysis of the fungal and bacterial decomposer communities using Illumina sequencing and qPCR, to understand whether local adaptation occurs and whether this was associated with litter mass loss dynamics. Temporal shifts in the decomposer community occurred, reflecting changes in litter chemistry over time. Fungal community composition was site dependent, while bacterial composition did not differ across sites. Total litter mass loss and rates of litter decomposition did not change across sites. Litter quality influenced the microbial community through the availability of different carbon sources. Additively, our results do not support the hypothesis that locally adapted microbial decomposers lead to a greater or faster mass loss. It is likely that high functional redundancy within decomposer communities regulated the decomposition, and thus greater future research attention should be given to trophic guilds rather than taxonomic composition.

Use of soil enzyme activities to assess the recovery of soil functions in abandoned coppice forest systems.

Coppicing consists of periodically cutting back tree stems to ground level to stimulate the growth of multiple stems from the stool. In Central Europe, many coppiced forests were abandoned at the beginning of the last century owing to a decline in the demand for charcoal and wood. This was assumed to enable the forests to recover and the properties to become similar to those of unmanaged forest (high forest). Most studies on abandoned coppiced forest have focused on forest recovery, while soil recovery has generally been overlooked. With the aim of filling this gap, this study investigated the effect of coppicing abandonment on soil recovery by analysing the changes in soil enzyme activities (dehydrogenase, ß-glucosidase, invertase, urease, acid phosphatase and arylsulphatase). Two differently managed sessile oak (Quercus petraea) forests were selected for study: a former coppice forest, abandoned >90 years ago, and an undisturbed forest. The analytical data were compared to assess the degree of recovery of the soil in the abandoned coppice forest. The soil organic matter content was two times lower in the abandoned coppice than in the high forest, suggesting that organic matter depletion due the past coppicing is a long-term effect. All of the absolute enzyme activities were also two times lower in the abandoned coppice forest soil than in the high forest soil. However, the specific enzyme activities were similar in both types of soil. This indicates that metabolic activity is similar in both soil types, suggesting that it either recovers faster than organic matter and soil enzyme activity or that, despite the depletion in organic matter and enzyme activities, metabolic activity was sustained in coppiced forest soil. However, in the latter case this would imply that organic matter and soil enzymes were lost in exactly the same proportion, which is highly improbable.