A carregar...
3 resultados
Resultados da pesquisa
A mostrar 1 - 3 de 3
- Arceuthobium Species (Viscaceae) Parasitizing an Angiosperm: The Unique Case of A. azoricum in the Azores IslandsPublication . Elias, Rui B.; Moura, Mónica; Roxo, Guilherme; Borges Silva, L; Pavão, Diogo C.; Resendes, Roberto; Pereira, Fernando; Nickrent, DanielArceuthobium azoricum Wiens & Hawksw. is a rare Azorean endemic epiphytic hemiparasite (mistletoe), which typically parasitizes branches of the gymnosperm Juniperus brevifolia (Hochst. ex Seub.) Antoine (Cupressaceae), which is also an Azorean endemic. Here, we describe a population of A. azoricum, on Pico Island, parasitizing Erica azorica Hochst. ex Seub. (Ericaceae), which is also an Azorean endemic. Our molecular analysis (using nuclear ribosomal internal transcribed spacer) showed no differences between individuals parasitizing Erica and Juniperus species. Moreover, a preliminary analysis showed no differences in morphological characteristics between accessions sampled from different hosts. Given that this is the first bona fide record of Arceuthobium sp. parasitizing an angiosperm, this population represents a unique host-shifting event, and its conservation is important because it may allow new insights into host recognition mechanisms in mistletoes. Immediate attention should be given to characterizing this Pico Island population using appropriate molecular methods and additional morphological analyses.
- A prevenção como método de conservação: O caso da Youngia japónica (crepe-do-japão) na ilha de São MiguelPublication . Roxo, Guilherme; Torres, Paulo; Afonso, Pedro; Rego, Rúben; Resendes, Roberto; Moura, MónicaUma espécie quando vive fora da sua área de distribuição nativa é denominada de espécie exótica (do grego exotikós, “de fora”). Algumas destas espécies coexistem com as espécies nativas de forma equilibrada, no entanto quando causam impactes ambientais e económicos negativos estas são designadas de espécies invasoras. No arquipélago dos Açores mais de 60% da flora vascular corresponde a espécies exóticas. Estas plantas foram introduzidas de forma consciente ou inconsciente, propagando-se e desenvolvendo-se espontaneamente, podendo impactar o nosso dia a dia quando afetam os serviços dos ecossistemas, com consequências negativas no fornecimento de água, regulação do clima, saúde pública, valor estético e cultural das paisagens, entre outras.
- Red listing the flora of the Green Islands reveals high extinction risk in the AzoresPublication . Roxo, Guilherme; Silva, Luís; Pires Bento da Silva Elias, Rui Miguel; Carine, Mark; McCartney, Ann; Borges Silva, Lurdes da Conceição; Rego, Rúben; Souto, Martin; Bateman, Richard; Tavares de Moura, Mónica MariaABSTRACT: Oceanic islands are global biodiversity hotspots, yet they face disproportionate risks of species extinction. The Azores archipelago holds a unique flora composed of 94 endemic vascular plant taxa (species and subspecies) that are strictly endemic to the Azores, which represents about 32% of the native vascular flora. Here, we present the first comprehensive IUCN Red List assessment of the Azorean endemic vascular flora, based on more than 10,600 curated occurrence records, herbaria specimens, and recent field surveys. We found that nearly 60% of assessed taxa are threatened with extinction, Endangered being the most frequent IUCN category. Two species are confirmed Extinct, and 12 taxa remain Data Deficient due to unresolved taxonomy. The Red List Index (RLI) for Azorean endemics was calculated at 0.602, indicating a concerning level of extinction risk and, importantly, providing a reference point for monitoring future changes in conservation status. Spatial analysis revealed that endemic taxa richness is highly uneven, with most areas hosting few or no endemics. Notably, 12 hotspots occur outside the current protected area network, leaving key refuges for endemic taxa unprotected. These findings underscore the urgent need to expand legal protection, prioritise the management of invasive taxa, restore degraded habitats, and integrate newly described taxa into conservation frameworks. By establishing a baseline for monitoring extinction risk, this study provides a critical tool to guide conservation action in the Azores, and contributes to broader efforts to safeguard the unique natural heritage of oceanic islands.