The 1.8 million ha of forest south of the Caspian Sea represent a remarkably intact ecosystem with numerous old‐growth features and unique species assemblages. To protect these forests, Iranian ...authorities recently passed a law which protects healthy trees but permits the removal of injured, dying and dead trees. To quantify the biodiversity effects of this strategy, we sampled saproxylic beetles and true bugs in 24 plots across the entire altitudinal gradient of Oriental beech. The composition of these communities as well as their overall richness and the richness of endemic and old‐growth indicator species were best explained by dead wood volume compared to other environmental variables. Due to the striking evidence that dead wood is the major driver of saproxylic diversity in these forests, we urge Iranian authorities to reconsider their law, redirecting logging toward healthy medium sized trees. Otherwise, a major loss in biodiversity, similar to that experienced in European beech forests, can be expected.
The conservation and sustainable use of forests and forest genetic resources (FGR) is a challenging task for scientists and foresters. Forest management practices can affect diversity on various ...levels: genetic, species, and ecosystem. Understanding past natural disturbance dynamics and their level of dependence on human disturbances and management practices is essential for the conservation and management of FGR, especially in the light of climate change. In this review, forest management practices and their impact on genetic composition are reviewed, synthesized, and interpreted in the light of existing national and international forest monitoring schemes and concepts from various European projects. There is a clear need and mandate for forest genetic monitoring (FGM), while the requirements thereof lack complementarity with existing forest monitoring. Due to certain obstacles (e.g., the lack of unified FGM implementation procedures across the countries, high implementation costs, large number of indicators and verifiers for FGM proposed in the past), merging FGM with existing forest monitoring is complicated. Nevertheless, FGM is of paramount importance for forestry and the natural environment in the future, regardless of the presence or existence of other monitoring systems, as it provides information no other monitoring system can yield. FGM can provide information related to adaptive and neutral genetic diversity changes over time, on a species and/or on a population basis and can serve as an early warning system for the detection of potentially harmful changes of forest adaptability. In addition, FGM offers knowledge on the adaptive potential of forests under the changing environment, which is important for the long-term conservation of FGR.
The vertical niche differentiation of genera of ectomycorrhiza (ECM) was assessed in a 17-year-old Norway spruce (Picea abies L. Karst.) plantation on a mountainous dolomitic site (1,050 m above sea ...level) of the Bavarian Limestone Alps. We determined ECM anatomotypes, recorded the abundance of corresponding ECM root tips and classified them into groups of ECM exploration types, which refer to the organisation and the extent of their extramatrical mycelia. The abundance of ECM was highest in the organic soil layers, compared to the mineral soil horizon. The ordination of the ECM communities and of the exploration types revealed segregation related to soil horizon properties. While Cenococcum geophilum preferred the organic soil layers, Lactarius spp., Tomentella spp. and Craterellus tubaeformis were generally most abundant in the mineral soil horizons. Cenococcum geophilum was the predominant species, possibly based on enhanced competitiveness under the prevailing site conditions. The short-distance exploration types (e.g. C. geophilum) preferentially colonised the organic soil layer, whereas the contact types (e.g. most of the Tomentella spp., C. tubaeformis) together with medium-distance types (e.g. Amphinema byssoides) were primarily associated with the underlying A-horizons. Therefore, the soil horizons had an important effect on the distribution of ECM and on their community structure. The spatial niche differentiation of ECM genera and exploration types is discussed in regard to specific physico-chemical properties of soil horizon and the assumed ecophysiological strategies of ECM.
Apomixis in angiosperms is asexual reproduction from seed. Its importance to angiospermous evolution and biodiversity has been difficult to assess mainly because of insufficient taxonomic ...documentation. Thus, we assembled literature reporting apomixis occurrences among angiosperms and transferred the information to an internet database (
http://www.apomixis.uni-goettingen.de
). We then searched for correlations between apomixis occurrences and well-established measures of taxonomic diversity and biogeography. Apomixis was found to be taxonomically widespread with no clear tendency to specific groups and to occur with sexuality at all taxonomic levels. Adventitious embryony was the most frequent form (148 genera) followed by apospory (110) and diplospory (68). All three forms are phylogenetically scattered, but this scattering is strongly associated with measures of biodiversity. Across apomictic-containing orders and families, numbers of apomict-containing genera were positively correlated with total numbers of genera. In general, apomict-containing orders, families, and subfamilies of Asteraceae, Poaceae, and Orchidaceae were larger, i.e., they possessed more families or genera, than non-apomict-containing orders, families or subfamilies. Furthermore, many apomict-containing genera were found to be highly cosmopolitan. In this respect, 62% occupy multiple geographic zones. Numbers of genera containing sporophytic or gametophytic apomicts decreased from the tropics to the arctic, a trend that parallels general biodiversity. While angiosperms appear to be predisposed to shift from sex to apomixis, there is also evidence of reversions to sexuality. Such reversions may result from genetic or epigenetic destabilization events accompanying hybridization, polyploidy, or other cytogenetic alterations. Because of increased within-plant genetic and genomic heterogeneity, range expansions and diversifications at the species and genus levels may occur more rapidly upon reversion to sexuality. The significantly-enriched representations of apomicts among highly diverse and geographically-extensive taxa, from genera to orders, support this conclusion.
In order to prevent corrosion damage, steel structures need to be protected. Coating systems achieve this by the isolation of the steel from its environment. Common binding agents are epoxide and ...polyurethane resins which harden by polyaddition reactions. In contact with water, various organic substances might be leached out and released into the aquatic environment potentially causing adverse effects. So far, no legal requirements are mandatory for the environmental sustainability of coating systems. To characterize emissions from steel coatings, recommendations for the ecotoxicological assessment of construction products were utilized. Seven different coating systems based on epoxide or polyurethane resins were leached in 8 steps (6 h–64 d), followed by the testing of acute toxic effects on bacteria and algae as well as estrogen-like and mutagenic effects. In addition, chemical analysis by GC-MS was performed to identify potentially toxic compounds released from the coating systems. Two systems tested did not show any significant effects in the bioassays. One coating system caused significant algal toxicity, none was found to cause mutagenic effects. The other coating systems mainly showed estrogenic effects and bacterial toxicity. The effects increased with increasing leaching time. 4-tert-butylphenol, which is used in epoxy resins as a hardener, was identified as the main contributor to acute and estrogenic effects in two coatings. The release mechanism of 4-tert-butylphenol was characterized by two different modelling approaches. It was found that the release from the most toxic coating is not explainable by an elevated content of 4-tert-butylphenol but more likely by the release mechanism that – in contrast to the less toxic coating – is controlled not only by diffusion. This finding might indicate a sub-optimal formulation of this coating system resulting in a less stable layer and thus an increased release of toxic compounds.
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•Anti-corrosion coatings can cause high bacterial toxicity and estrogenic effects.•4-tert-butylphenol was identified as main contributor to acute and toxic effects.•Emission is controlled by the underlying release mechanism rather than concentration.•Coatings based on polyurethane resin were less harmful than epoxide resin based.•Proposal for an efficient assessment of coating systems based on the DIBt concept.
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•Epoxy resins (EP) undergo photooxidative degradation upon UV-irradiation.•ToF-SIMS and ICP-MS prove that inorganic pigments are exposed on the surface.•LC-MS/MS analyses provide ...insights into degradation pathways of the EP polymer.•A mechanism for early delamination of weathered EP/PUR coating systems is proposed.
Epoxy resin coatings applied to steel constructions for corrosion protection purposes are often exposed to UV-irradiation and weathering during the construction process. Chemical alteration of the hardened coating might lead to i) the release of potentially harmful substances into the environment and ii) delamination of the polyurethane top layer. However, chemical processes and mechanisms occurring on the surfaces of exposed epoxy resin coatings are not fully understood yet. Herein, we present an innovative approach combining time-of-flight secondary ion mass spectrometry (ToF-SIMS) with inductively coupled plasma mass spectrometry (ICP-MS) and liquid chromatography mass spectrometry (LC-MS) enabling the elucidation of underlying chemical processes and the identification of released organic and inorganic photolytic products. IR-spectroscopy and experiments targeting the acidity/pH-value changes on top of weathered surfaces complement our investigations. It was confirmed that UV-A irradiation leads to photooxidative degradation of the epoxy resin and that inorganic photolytic products are exposed on the weathered surfaces. Polar moieties (hydroxyls, carbonyls, carboxyls, amines) and released metalloids form a hydrophilic surface layer, which hinders adhesion and eventually prevents profound chemical linkage of the polyurethane top layer. Thus, an early delamination of the top layer might occur very likely.
•Spruce bark beetle infestations significantly change forest structural heterogeneity.•Early-seral heterogeneity persists for at least three decades in mountain forests.•Autotrophs, phytophagous and ...pollinators benefit in early-seral stage.•Protracted regeneration periods are recommended for forest management to support biodiversity.
Early-successional forest ecosystems developing after natural disturbances, such as fire, windthrow or insect outbreaks, can support high diversity of habitat structures, species and processes. However, the specific structural and multi-taxon responses that best define a distinct early-seral pre-forest phase, and the longevity of that phase, remain important research questions. To address these questions, we assessed stand structural heterogeneity and species density of various taxa across three biological kingdoms in the initial early-seral period (∼3years after severe bark beetle outbreak), advanced early-seral period (∼17–25years after severe bark beetle outbreak) and mature spruce forests in unmanaged montane/high-montane ecosystems in Southeastern Germany. We evaluated the hypothesis that changes in structural heterogeneity and increases in diversity would peak in the initial stage and attenuate toward mature forest conditions by 17–25years as the tree canopy closed.
We found a clear change in forest structural heterogeneity following the outbreak – most prominently in reduced cover and more clustered patterning of live trees, increased light availability, increased cover of shrubs and herbs, and high volume of dead wood. Most of these structural changes were not ephemeral after outbreaks, but remained high or even increased after multiple decades, suggesting persistence of early-seral heterogeneity well into succession.
Biodiversity as measured by species density and rarefaction curves showed variable responses to early-seral conditions depending on taxon and functional group. While some groups either showed no significant change with disturbance (e.g., most epigeics associated with the ground surface), or initially peaked after disturbance before declining quickly (e.g., saproxylic beetles specializing on fresh dead wood), several key groups showed maximum diversity in the advanced early-seral stage (e.g., herbs, herbivores, pollinators) – indicating that the timeframe over which increases occurred tended to be on the order of decades rather than years.
Our findings suggest that in unmanaged forests after bark beetle attack, a structurally complex phase prior to tree canopy closure can last several decades, and that many aspects of early-seral biodiversity and ecosystem function only fully develop given this extended time period. Where management of montane forests includes objectives for sustaining biodiversity, accommodating the protracted early-seral stage is important to supporting the full range of organisms and functions associated with canopy-opening disturbances.
The conservation and sustainable use of forest genetic resources (FGR) in the face of the threat posed by climate change has become a challenging task for scientists and foresters. Genetic ...variability and diversity of FGR and forest reproductive material (FRM) will play a key role in forest adaptation under future environmental conditions. The need for protection of FGR has been widely discussed on the pan-European and national scales. However, at the national level, in some countries, the conservation and use of rare and scattered tree species FGR is overlooked or given low priority. Our study focuses on the delineation of provenance regions, selection of seed stands and gene conservation units of wild service tree in southern Germany. A total of 106 natural populations of wild service tree were screened based on demographic and phenotypic criteria. In order to represent the distribution range of wild service tree in southern Germany, 34 populations were selected for genetic analysis with eight variable microsatellite markers in Bavaria (BY) and Baden-Württemberg (BW). Results of AMOVA (analysis of molecular variance) showed that genetic variation is mainly distributed within populations (96%), while only a small amount occurred among them (
F
ST
= 0.04). The Mantel test indicated isolation by distance, and Bayesian clustering indicated the highest probability of four genetic clusters of wild service tree in southern Germany. Finally, 12 stands out of 34 were proposed as seed stands based on high-quality phenotypes and high genetic diversity (effective no. of alleles Ne ≥ 5.5). Five populations were proposed as gene conservation units, and seven forest stands were included in the list as potential future seed stands. Overall, assessment of genetic diversity should be applied in future to evaluate the level of genetic diversity of all selected seed stands. Our study thus presents a concept for delineation of provenance regions, selection of seed stands and gene conservation units based on demographic–phenotypic parameters and genetic markers.
Protected areas worldwide are important to maintaining biodiversity and providing recreational opportunities to society. However, many protected areas are affected by unprecedented, large and severe ...natural disturbances, like bark beetle outbreaks. Due to the contrasting responses of different taxonomic groups to disturbance events and largely negative human perceptions of disturbed landscapes, there are conflicting opinions about the appropriate way of managing affected stands. Aligning these different objectives and understanding the responses of biodiversity and visitors' perceptions to different disturbance severities is a prerequisite for disturbance management in protected areas. We conducted multi-taxon biodiversity surveys – including meta-barcoding hyperdiverse groups such as insects and fungi – and analysed the restorativeness (i.e. the landscape's ability to renew personal cognitive capacities for forest visitors) using visitor surveys in five national parks throughout Europe. Response curves of biodiversity and restorativeness were analysed along a continuous gradient of bark beetle infestation severities in Norway spruce forests on the same study plots. Arthropod biomass and the diversity of primary producers and pollinators increased linearly with increasing disturbance severity, while overall multi-diversity (an index of the average scaled species richness per taxonomic group) did not change. Restorativeness decreased linearly with increasing disturbance severity; however, even heavily disturbed forests still had high restorativeness. In spite of the ongoing debates about disturbance management, the high biodiversity and restorativeness that accompany disturbance suggest that major goals of protected areas are not threatened by bark beetle disturbances.
•Arthropod biomass increases along a disturbance severity gradient.•Arthropod OTU richness does not respond to increasing disturbance severity.•Multi-diversity-index is stable along a disturbance severity gradient.•Primary producer and pollinator richness increases with disturbance severity.•Severely disturbed forests have still high restorativeness values.
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