Biologisk mangfold og økosystemfunksjoner i gamle eiker

Veteran trees are keystone structures in landscapes, hotspots for biodiversity and have high cultural value. They are also declining globally, and this threatens the species that are dependent on them, and the ecosystem functions they promote. Ecosystem functions are the physicochemical and biological processes that occur within ecosystems that maintain life. A key link between biodiversity and ecosystem functioning is the traits of the species. This diversity of traits is also known as functional diversity, and high levels of functional diversity in a community promote multiple ecosystem processes and make these processes more resilient to change. There is a large amount of evidence to support the conclusion that biodiversity influences ecosystem functioning, but few studies address this related to invertebrate diversity in veteran trees. My research has explored the multifaceted predictors of taxonomic and functional diversity of veteran oaks invertebrate communities, and measured the contribution of these communities to ecosystem functioning. In Paper 1, I considered three possible ecosystem functions promoted by veteran oak beetle communities (decomposition, predation and pollination), and explored how the veteran oaks and their landscape contexts influence this diversity (both taxonomic and functional). In the two corresponding papers (Papers 2 and 3), I focused more closely on predation and decomposition (respectively), and examined the differences in these processes and beetle communities involved in them between veteran and young oaks. Lastly, in Paper 4 I used a mesocosm experiment to explore how community complexity influences biotic interactions and decomposition in tree hollows. All my research was conducted around veteran oaks in southern Norway. In Paper 1, I found that the features of veteran trees (e.g.: senescence, circumference and regrowth) and the landscape that they were in had different influences on species richness and functional diversity within the different groups of decomposers, predatory and flower visiting beetles. In Paper 2, I found that there were more species of predatory beetles with greater functional diversity around veteran oaks than young oaks, and this corresponded with greater invertebrate predation rates. In Paper 3, I found a similar effect on the wood decomposing beetles, with a greater number of species and higher functional diversity around veteran trees than young trees. However, I found the opposite effect on decomposition of the small diameter wood, with slower rates around the veteran trees. In Paper 4, I found that community complexity increased decomposition rates and wood mold production in tree hollows, and that macrofauna influenced the decomposition pathway and nematode community structure and maturity. The findings from my research support the concept that veteran trees are important for biodiversity, and indicate that veteran trees and their communities influence ecosystem functions, such as invertebrate predation and decomposition. They also highlight the importance of community complexity and habitat heterogeneity for promoting biodiversity and ecosystem functioning. Results from my work indicate that there is the potential for synergies between the conservation of veteran trees and sustainable agriculture and forestry. Protecting and valuing veteran trees and their communities, and reintegrating them into land use practices, is an essential step towards a more sustainable system of management, and has the possibility of enhancing the wellbeing of people while promoting biodiversity.Gamle trær er nøkkelstrukturer i landskapet, de er viktige for biologisk mangfold og de har høy kulturell verdi. De minker globalt, og dette truer artene som er avhengige av dem samt de økosystemfunksjonene disse trærne fremmer. Økosystemfunksjoner er de fysisk-kjemiske og biologiske prosessene som forekommer i økosystemer og som støtter opp om liv. Artenes egenskaper utgjør en sentral kobling mellom biologisk mangfold og økosystemfunksjoner. Dette mangfoldet av egenskaper er også kjent som funksjonelt mangfold, og høye nivåer av funksjonelt mangfold i et samfunn fremmer flere økosystemprosesser og gjør disse prosessene mer motstandsdyktige mot endring. Mye forskning peker på at biologisk mangfold påvirker økosystemfunksjon, men få studier tar for seg dette i sammenheng med mangfold av insekter i gamle trær. Forskningen min har utforsket de flersidige driverne for taksonomisk og funksjonelt mangfold i insektmiljøer som forekommer i gamle eiketrær, og målt bidragene fra disse til økosystemfunksjoner. Resultatene fra forskningen min støtter oppfatningen om at gamle trær er viktige for biologisk mangfold, og peker på at gamle trær og samfunnene deres bidrar til viktige økosystemfunksjoner, eksempelvis predasjon av insekter og nedbrytning av organisk materiale. Resultatene fremhever også viktigheten av samfunnskompleksitet og habitatsmangfold for å fremme biologisk mangfold og viktige økosystemfunksjoner. Forskningen min viser dessuten at det finnes mulige synergier mellom bevaring av gamle trær og bærekraftig jordbruk. Å beskytte og verdsette gamle trær og lokalsamfunnene deres, samt integrere disse på nytt i landbrukspraksis, er et viktig skritt mot et mer bærekraftig forvaltningssystem som har mulighet for å forbedre folks velvære samtidig som det fremmer biologisk mangfold

Ectoparasite (Ceratophyllus vagabundus vagabundus) infestations reduce hatching success in precocial birds (Branta leucopsis) nesting in the High Arctic

Arctic terrestrial ecosystems are ideal systems to study host-parasite interactions because they are sensitive and have fewer confounding interactions than lower latitudes. Since the Arctic is experiencing rapid climate change, research there can provide models to better understand and predict future changes in other systems. The Barnacle goose (Branta leucopsis) and its ectoparasite the flea (Ceratophyllus vagabundus vagabundus) is an ideal Arctic host-parasite system to study because Barnacle geese have important roles in Arctic ecosystems as selective grazers and prey items and have been intensively studied for decades. Also, recent studies suggest that Arctic avian flea infestations may be increasing, possibly due to climate change. However, few studies have considered the effect of fleas on Arctic nesting birds and little is known of Arctic avian flea ecology, most importantly whether they overwinter in the High Arctic or are reintroduced each summer by migrating birds. Furthermore, sampling methods for avian fleas are time-consuming and semi-invasive to their hosts. Therefore, the project had four aims: (i) contribute to the knowledge of Arctic flea ecology by looking for evidence of overwintering, (ii) use an experimental study to assess the impact of flea infestations on the hatching success of Barnacle goose eggs, (iii) assess the simple and disturbance-free method of estimating fleas with photographs of blood spots on goose eggs, (iv) and test the results of both the experimental study as well as the application of blood spots as a proxy measure for flea infestations through a larger observational study. It was found that fleas were likely overwintering in empty nest bowls and some evidence indicated that they might be capable of a two-year life cycle in the High Arctic. The findings from the experimental study indicated that heavy flea infestations had a negative impact on the hatching success of Barnacle goose eggs. It was also determined that blood spots were a good proxy measure of flea infestations, but become less accurate through incubation due to wear from incubating birds. Finally, the observational study supported the findings of the experimental study and demonstrated the power and simplicity of using blood spots as a proxy measure for flea infestations. Based on these findings, it is suggested that researchers interested in either reproductive success or incubation behavior of Barnacle geese should include a measure of flea infestations in their studies and using blood spots as a proxy measure is a simple and disturbance-free method of doing this.M-ECO

Functional structure of European forest beetle communities is enhanced by rare species

Biodiverse communities have been shown to sustain high levels of multifunctionality and thus a loss of species likely negatively impacts ecosystem functions. For most taxa, however, roles of individual species are poorly known. Rare species, often most likely to go extinct, may have unique traits and functional roles. Alternatively, rare species may be functionally redundant, such that their loss would not disrupt ecosystem functions. We quantified the functional role of rare species by using captures of wood-living (saproxylic) beetle species, combined with recent databases of morphological and ecological traits, from three regions in central and northern Europe. Using a rarity index based on species' local abundance, geographic range, and habitat breadth, we used local and regional species removal simulations to examine the contributions of both the rarest and the most common beetle species to three measures of community functional structure: functional richness, functional specialization, and functional originality. Both regionally and locally, all three measures declined more rapidly when rare species were removed than under common (or random) species removal scenarios. These consistent patterns across scales and among forest types give evidence that rare species provide unique functional contributions, and their loss may disproportionately impact ecosystem functions. This implies that conservation measures targeting rare and endangered species, such as preserving intact forests with dead wood and mature trees, can provide broader ecosystem-level benefits. Experimental research linking functional structure to ecosystem processes should be prioritized to increase understanding of the functional consequences of species loss and to develop more effective conservation strategies

Herbivory on the pedunculate oak along an urbanization gradient in Europe : Effects of impervious surface, local tree cover, and insect feeding guild

Urbanization is an important driver of the diversity and abundance of tree-associated insect herbivores, but its consequences for insect herbivory are poorly understood. A likely source of variability among studies is the insufficient consideration of intra-urban variability in forest cover. With the help of citizen scientists, we investigated the independent and interactive effects of local canopy cover and percentage of impervious surface on insect herbivory in the pedunculate oak (Quercus robur L.) throughout most of its geographic range in Europe. We found that the damage caused by chewing insect herbivores as well as the incidence of leaf-mining and gall-inducing herbivores consistently decreased with increasing impervious surface around focal oaks. Herbivory by chewing herbivores increased with increasing forest cover, regardless of impervious surface. In contrast, an increase in local canopy cover buffered the negative effect of impervious surface on leaf miners and strengthened its effect on gall inducers. These results show that-just like in non-urban areas-plant-herbivore interactions in cities are structured by a complex set of interacting factors. This highlights that local habitat characteristics within cities have the potential to attenuate or modify the effect of impervious surfaces on biotic interactions.Peer reviewe

Herbivory on the pedunculate oak along an urbanization gradient in Europe : Effects of impervious surface, local tree cover, and insect feeding guild

Urbanization is an important driver of the diversity and abundance of tree-associated insect herbivores, but its consequences for insect herbivory are poorly understood. A likely source of variability among studies is the insufficient consideration of intraurban variability in forest cover. With the help of citizen scientists, we investigated the independent and interactive effects of local canopy cover and percentage of impervious surface on insect herbivory in the pedunculate oak (Quercus robur L.) throughout most of its geographic range in Europe. We found that the damage caused by chewing insect herbivores as well as the incidence of leaf-mining and gall-inducing herbivores consistently decreased with increasing impervious surface around focal oaks. Herbivory by chewing herbivores increased with increasing forest cover, regardless of impervious surface. In contrast, an increase in local canopy cover buffered the negative effect of impervious surface on leaf miners and strengthened its effect on gall inducers. These results show that – just like in non-urban areas – plant-herbivore interactions in cities are structured by a complex set of interacting factors. This highlights that local habitat characteristics within cities have the potential to attenuate or modify the effect of impervious surfaces on biotic interactions.Agence Nationale de la Recherche, Grant/Award Number: ANR-10--LABX-45; Fondation BNP Paribas.info:eu-repo/semantics/publishedVersio

Herbivory on the pedunculate oak along an urbanization gradient in Europe: Effects of impervious surface, local tree cover, and insect feeding guild

Urbanization is an important driver of the diversity and abundance of tree-associated insect herbivores, but its consequences for insect herbivory are poorly understood. A likely source of variability among studies is the insufficient consideration of intra-urban variability in forest cover. With the help of citizen scientists, we investigated the independent and interactive effects of local canopy cover and percentage of impervious surface on insect herbivory in the pedunculate oak (Quercus robur L.) throughout most of its geographic range in Europe. We found that the damage caused by chewing insect herbivores as well as the incidence of leaf-mining and gall-inducing herbivores consistently decreased with increasing impervious surface around focal oaks. Herbivory by chewing herbivores increased with increasing forest cover, regardless of impervious surface. In contrast, an increase in local canopy cover buffered the negative effect of impervious surface on leaf miners and strengthened its effect on gall inducers. These results show that-just like in non-urban areas-plant-herbivore interactions in cities are structured by a complex set of interacting factors. This highlights that local habitat characteristics within cities have the potential to attenuate or modify the effect of impervious surfaces on biotic interactions

Pratos e mais pratos: louças domésticas, divisões culturais e limites sociais no Rio de Janeiro, século XIX

Reply to ten comments on a paper published in the last issue of this journal. The discussion follows along six main lines: History museums, identity, ideology and the category of nation; the need of material collections and their modalities: patrimonial, operational, virtual; theater versus laboratory; visitors and their ambiguities; Public History: the museum and the academy.Resposta aos comentários de dez especialistas que contribuíram no debate de texto publicado no último número desta revista. A discussão orientou-se segundo seis tópicos principais: museus históricos, identidade, ideologia e a categoria de nação; a necessidade de acervos materiais e suas modalidades: acervo patrimonial, operacional, virtual; teatro versus laboratório; o público e suas ambigüidades; História Pública: o museu e a Academia

Global tracking of marine megafauna space use reveals how to achieve conservation targets

The recent Kunming-Montreal Global Biodiversity Framework (GBF) sets ambitious goals but no clear pathway for how zero loss of important biodiversity areas and halting human-induced extinction of threatened species will be achieved. We assembled a multi-taxa tracking dataset (11 million geopositions from 15,845 tracked individuals across 121 species) to provide a global assessment of space use of highly mobile marine megafauna, showing that 63% of the area that they cover is used 80% of the time as important migratory corridors or residence areas. The GBF 30% threshold (Target 3) will be insufficient for marine megafauna’s effective conservation, leaving important areas exposed to major anthropogenic threats. Coupling area protection with mitigation strategies (e.g., fishing regulation, wildlife-traffic separation) will be essential to reach international goals and conserve biodiversity

Ectoparasite (Ceratophyllus vagabundus vagabundus) infestations reduce hatching success in precocial birds (Branta leucopsis) nesting in the High Arctic

Arctic terrestrial ecosystems are ideal systems to study host-parasite interactions because they are sensitive and have fewer confounding interactions than lower latitudes. Since the Arctic is experiencing rapid climate change, research there can provide models to better understand and predict future changes in other systems. The Barnacle goose (Branta leucopsis) and its ectoparasite the flea (Ceratophyllus vagabundus vagabundus) is an ideal Arctic host-parasite system to study because Barnacle geese have important roles in Arctic ecosystems as selective grazers and prey items and have been intensively studied for decades. Also, recent studies suggest that Arctic avian flea infestations may be increasing, possibly due to climate change. However, few studies have considered the effect of fleas on Arctic nesting birds and little is known of Arctic avian flea ecology, most importantly whether they overwinter in the High Arctic or are reintroduced each summer by migrating birds. Furthermore, sampling methods for avian fleas are time-consuming and semi-invasive to their hosts. Therefore, the project had four aims: (i) contribute to the knowledge of Arctic flea ecology by looking for evidence of overwintering, (ii) use an experimental study to assess the impact of flea infestations on the hatching success of Barnacle goose eggs, (iii) assess the simple and disturbance-free method of estimating fleas with photographs of blood spots on goose eggs, (iv) and test the results of both the experimental study as well as the application of blood spots as a proxy measure for flea infestations through a larger observational study. It was found that fleas were likely overwintering in empty nest bowls and some evidence indicated that they might be capable of a two-year life cycle in the High Arctic. The findings from the experimental study indicated that heavy flea infestations had a negative impact on the hatching success of Barnacle goose eggs. It was also determined that blood spots were a good proxy measure of flea infestations, but become less accurate through incubation due to wear from incubating birds. Finally, the observational study supported the findings of the experimental study and demonstrated the power and simplicity of using blood spots as a proxy measure for flea infestations. Based on these findings, it is suggested that researchers interested in either reproductive success or incubation behavior of Barnacle geese should include a measure of flea infestations in their studies and using blood spots as a proxy measure is a simple and disturbance-free method of doing this.M-ECO

Ectoparasite (Ceratophyllus vagabundus vagabundus) infestations reduce hatching success in precocial birds (Branta leucopsis) nesting in the High Arctic

Arctic terrestrial ecosystems are ideal systems to study host-parasite interactions because they are sensitive and have fewer confounding interactions than lower latitudes. Since the Arctic is experiencing rapid climate change, research there can provide models to better understand and predict future changes in other systems. The Barnacle goose (Branta leucopsis) and its ectoparasite the flea (Ceratophyllus vagabundus vagabundus) is an ideal Arctic host-parasite system to study because Barnacle geese have important roles in Arctic ecosystems as selective grazers and prey items and have been intensively studied for decades. Also, recent studies suggest that Arctic avian flea infestations may be increasing, possibly due to climate change. However, few studies have considered the effect of fleas on Arctic nesting birds and little is known of Arctic avian flea ecology, most importantly whether they overwinter in the High Arctic or are reintroduced each summer by migrating birds. Furthermore, sampling methods for avian fleas are time-consuming and semi-invasive to their hosts. Therefore, the project had four aims: (i) contribute to the knowledge of Arctic flea ecology by looking for evidence of overwintering, (ii) use an experimental study to assess the impact of flea infestations on the hatching success of Barnacle goose eggs, (iii) assess the simple and disturbance-free method of estimating fleas with photographs of blood spots on goose eggs, (iv) and test the results of both the experimental study as well as the application of blood spots as a proxy measure for flea infestations through a larger observational study. It was found that fleas were likely overwintering in empty nest bowls and some evidence indicated that they might be capable of a two-year life cycle in the High Arctic. The findings from the experimental study indicated that heavy flea infestations had a negative impact on the hatching success of Barnacle goose eggs. It was also determined that blood spots were a good proxy measure of flea infestations, but become less accurate through incubation due to wear from incubating birds. Finally, the observational study supported the findings of the experimental study and demonstrated the power and simplicity of using blood spots as a proxy measure for flea infestations. Based on these findings, it is suggested that researchers interested in either reproductive success or incubation behavior of Barnacle geese should include a measure of flea infestations in their studies and using blood spots as a proxy measure is a simple and disturbance-free method of doing this