Establishment and remodelling of the dendritic cell network in tissues

Conventional dendritic cells (cDCs) are leucocytes that act as sentinel cells, sensing the extracellular environment and initiating immune responses against infection and cancer. cDCs develop from a common progenitor in the bone marrow (BM) that travels via the blood in the form of a pre-cDC to seed tissues. How pre-cDCs colonise different organs, whether this is affected by infection and how BM production is matched to cDC demand in the periphery remains poorly understood. During my PhD I used a mouse model for multicolour fate mapping of cDC progenitors and found that many pre-cDCs and cDCs divide in tissues generating single cDC clones. Upon infection with influenza A virus, lung cDCs increase in number due to accelerated CCR2-dependent recruitment of pre-cDCs from the BM rather than local proliferation, diluting pre-existing clones. This recruitment generates new waves of cDCs in the lung that seem to be necessary for inducing antiviral immunity. Preliminary results using a reporter mouse for DC progenitors show that more cells localise close to BM sinusoids during infection, possibly to favour the rapid release of pre-cDCs into the blood circulation. Interestingly, cancer and vaccine adjuvants also mobilise BM cDC progenitors, demonstrating that this is probably a conserved mechanism by which the cDC network adapts to different challenges. In addition, pre-cDCs can directly sense pathogen-associated molecular patterns via toll-like receptors, which might be necessary for the progenitors to respond to infection or tissue damage. In sum, my results provide evidence for a tightly regulated cDC network that is often organised in clones. However, when a bigger arsenal of cDCs is required, the BM responds by pumping out more pre-cDCs, which is a new component of immunity to infection. More studies might reveal whether CCR2 also drive this phenomenon during cancer and the mechanism underlying pre-cDC exit from the BM

Metapopulation perspective to institutional fit : maintenance of dynamic habitat networks

Species living in metapopulations depend on connected habitat networks for their survival. If habitat networks experience fast temporal dynamics, species conservation requires preventing habitat discontinuities that could lead to metapopulation extinctions. However, few institutional solutions exist for the maintenance of spatiotemporally dynamic habitat networks outside of protected areas. To explore this often neglected problem, we studied the institutional fit of false heath fritillary (Melitaea diamina) conservation in Finland from the perspective of conservation institutions' ability to manage early successional habitat availability for this endangered species. We identified four institutional arrangements that enable effective conservation management of dynamic habitat networks: (1) acknowledgment of habitat dynamics, (2) monitoring of and responding to changes in the habitat network, (3) management of resources for fluctuating resource needs, and (4) scaling of activities through flexible collaborations. These arrangements provide the institutional flexibility needed for responding to temporal changes in habitat availability.Peer reviewe

Climate change can cause complex responses in Baltic Sea macroalgae : A systematic review

Estuarine macroalgae are important primary producers in aquatic ecosystems, and often foundation species providing structurally complex habitat. Climate change alters many abiotic factors that affect their long-term persistence and distribution. Here, we review the existing scientific literature on the tolerance of key macroalgal species in the Baltic Sea, the world's largest brackish water body. Elevated temperature is expected to intensify coastal eutrophication, further promoting growth of opportunistic, filamentous species, especially green algae, which are often species associated with intensive filamentous algal blooms. Declining salinities will push the distributions of marine species towards south, which may alter the Baltic Sea community compositions towards a more limnic state. Together with increasing eutrophication trends this may cause losses in marine-originating foundation species such as Fucus, causing severe biodiversity impacts. Experimental results on ocean acidification effects on macroalgae are mixed, with only few studies conducted in the Baltic Sea. We conclude that climate change can alter the structure and functioning of macroalgal ecosystems especially in the northern Baltic coastal areas, and can potentially act synergistically with eutrophication. We briefly discuss potential adaptation measures.Peer reviewe

Bird assemblages in a Malagasy forest-agricultural frontier : Effects of habitat structure and forest cover

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The role of protected areas in supporting human health : a call to broaden the assessment of conservation outcomes

Ongoing global biodiversity loss has far-reaching consequences for human health and well-being. While protected areas (PAs) have become a major policy instrument for biodiversity conservation, their role in supporting human health remains unclear. Here, we synthesize both positive and negative aspects of PAs on different dimensions of human health and provide several theoretical advances to assess the effectiveness of PAs in promoting human health. We finally identify three major research gaps requiring urgent attention. Implementing an interdisciplinary research program remains a priority to better comprehend the linkages between human health, ecosystem services and conservation policies at global scale. We believe this is key to improve the management of PAs and their surrounding areas and foster co-benefits for biodiversity and human health.Peer reviewe

Linking Biodiversity Conservation and Education: an exploratory research of Education Programmes implemented around Protected Areas in Madagascar

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Linking biodiversity conservation and education: perspectives from education programmes in Madagascar

Education is used to foster supportive behaviour for conservation. This paper examines how environmental education is implemented in Madagascar, and its potential for conservation. These reflections are based on literature insights and in-depth experiences from the field.. We found that environmental education is only marginally integrated in the national curriculum and NGOs are the primary promoters. Evaluation methods focus on quantifying short-term changes in knowledge and attitudes, and interventions fail to integrate local knowledge, values and needs. We call for researchers to examine the long-term impacts, on governmental commitment and support, and for future interventions to be inclusive and locally meaningful.RésuméL'éducation est un moyen utilisé pour encourager les comportements favorables à la conservation, en particulier dans les communautés locales vivant autour des aires protégées. À partir de la littérature et d’expériences sur le terrain, cette contribution examine les manières dont l'éducation environnementale est mise en œuvre à Madagascar, et son potentiel dans la conservation. Il a été constaté que, dans le cadre des écoles primaires, l'éducation environnementale n’est intégrée que de façon marginale dans le curriculum, et les ONG sont les principaux acteurs qui promeuvent l'éducation environnementale. Le principal cible les élèves pour conduire des activités dans le cadre strictement scolaire avec peu de visites dans les aires protégées. Les méthodes d'évaluation se concentrent sur la quantification des changements à court terme dans les connaissances et les attitudes, et non dans les comportements. Les interventions ne parviennent pas à intégrer les connaissances, les valeurs et les besoins locaux. L'influence de l'éducation sur le succès de la conservation reste floue, de sorte qu’il est proposé que la recherche examine également les impacts qualitatifs et comportementaux à long terme des interventions éducatives, l’engagement et le soutien du gouvernement national, et que les futures interventions soient inclusives et significatives au niveau local

Quality of governance and effectiveness of protected areas: crucial concepts for conservation planning

Protected areas (PAs) are a key tool for biodiversity conservation and play a central role in the Convention on Biological Diversity. Recently, the effectiveness of PAs has been questioned, and assessing how effective they are in enabling the future persistence of biodiversity is not trivial. Here, we focus on terrestrial PAs and clarify the terminology related to PA effectiveness, distinguishing between management and ecological aspects. We suggest that the quality of governance affects both aspects of effectiveness but recognize a lack of synthetic understanding of the topic. We present a conceptual framework linking the underlying mechanisms by which the quality of governance affects conservation outcomes in PAs and how this relates to conservation planning. We show that it is crucial to separate pressure and response and how these together will lead to the observed conservation outcomes. We urge for more focused attention on governance factors and in particular more empirical research on how to address causality and how to account for the quality of governance when prioritizing actions. Our framework is linked to the classic concepts of systematic conservation planning and clarifies the strategies available to achieve a comprehensive and effective network of PAs.Peer reviewe