Browsing by Person "Razanajatovo, Mialy"

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    Floral visitation to alien plants is non‐linearly related to their phylogenetic and floral similarity to native plants
    (2022) Razanajatovo, Mialy; Rakoto Joseph, Felana; Rajaonarivelo Andrianina, Princy; van Kleunen, Mark
    Biological invasions are key to understanding ecological processes that determine the formation of novel interactions. Alien species can negatively impact floral visitation to native species, but native species may also facilitate early establishment of closely related alien species by providing a preadapted pollinator community. We tested whether floral visitation to alien species depended on phylogenetic relatedness and floral similarity to native species. In a field experiment, we simulated the early stages of an invasion by adding potted alien plants into co‐flowering native communities. We paired each alien plant with a host native plant, and recorded floral visitation to them for 3,068 hr (totalling 84,814 visits). We used 34 alien and 20 native species in 151 species combinations. We tested whether the number of floral visits to alien plants, the proportion of visits to alien plant relative to visits to both alien and native plants, and the similarity in flower visitor compositions of alien and native plants depended on phylogenetic and floral trait distances between alien and native species. Floral visitation to alien species was highest when they had intermediate floral trait distances to native species, and either low or high phylogenetic distances. Alien species received more similar flower‐visitor groups to natives when they had low phylogenetic and either low or high floral trait distances to native species. Co‐flowering native species may facilitate floral visitation to closely related alien species, and distantly related alien plants seem to avoid competition for flower visitors with native plants. Alien species with similar floral traits to natives compete with them for flower visitors, and alien species with dissimilar floral traits may not share flower visitors with native species. Alien species with intermediate floral trait distances to natives are most likely to receive flower visitors, as they are not too dissimilar and may still share flower visitors with native species, but not too similar to compete for flower visitors with them. The non‐linear patterns between floral visitation and similarity of the alien and native species suggest that an interplay of facilitation and competition simultaneously drives the formation of novel plant‐pollinator interactions.
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    Nature's contributions to human well‐being under climate change: Evidence from Central and Eastern Madagascar
    (2024) Petzold, Jan; Kosanic, Aleksandra; Rakoto Joseph, Felana; Rajaonarivelo Andrianina, Princy; Ranaivosoa‐Toandro, Sitraka Mireille; Andriamihaja, Onintsoa Ravaka; Voahanginirina, Leonnie Marcelline; Thien, Lara; Razanajatovo, Mialy
    Anthropogenic climate change has an unprecedented impact on ecosystems and their services, with severe consequences for human well‐being, particularly for the marginalised and vulnerable members of society in the Global South. The well‐being of communities relies not only on material and regulating services ecosystems provide but also on non‐material services. In this paper, we unravel the diverse ways that climate change impacts affect Nature's Contributions to People (NCP) and the well‐being of rural populations in four sites in Madagascar—a biodiversity hotspot but one of the economically poorest countries in the world. We conducted participatory community workshops, mapping and semi‐structured interviews with local residents across social subgroups to understand the mechanisms of climate‐related degradation and the resulting impacts on different dimensions of human well‐being through an NCP lens. We found that non‐material services are generally more often associated with well‐being effects. Climate change degrades material and non‐material services through sea level rise, biodiversity loss, drought, precipitation and temperature variability, with consequences for materials, companionship and labour, food and feed, and physical and psychological experiences. Loss of land and forests is expressed through ecological grief. The outcome of our research provides evidence‐based information to local policymakers, conservation practitioners, and climate change agencies. This information can help improve government efforts toward holistic conservation and climate change adaptation by addressing the impacts on the physical and mental well‐being of the most vulnerable communities. Read the free Plain Language Summary for this article on the Journal blog.