Percorrer por autor "Castro, Paulo"
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- Invasive dynamics of the signal crayfish Pacifastacus leniusculus in a protected areaPublication . Carvalho, Francisco; Alves, Henrique; Pascoal, Cláudia; Castro, Paulo; Miranda, Fernando Jorge Veloso; Teixeira, Amílcar; Cássio, Fernanda; Sousa, RonaldoInvasive species have been drivers of biodiversity loss and functional changes in aquatic ecosystems, including in protected areas. Therefore, monitoring population invasion dynamics and biological traits is fundamental to better understand their ecological and economic impacts and for management actions development. We followed signal crayfish (Pacifastacus leniusculus) invasion in Rabaçal River upper reach at Montesinho Natural Park, Portugal. We collected information on the spread and biological traits (abundance, size, weight, physical condition, sex ratio, and aggressiveness) to assess differences between invasion core and front areas and among years. Signal crayfish population remained restricted since first reports in 2013 in the invasion core until 2017. After 2019, signal crayfish population has been spreading downstream, decreasing abundance at invasion core but increasing at invasion front. Significant higher number of crayfish with claw loss indicate potential higher signs of aggressiveness in the invasion front. Results also demonstrate a significant dominance of females although sex ratio is closer to 1:1 at the invasion front. Overall, results indicate signal crayfish is spreading and increasing their abundance at Rabaçal River highlighting the need for immediate management actions to hold dispersion and mitigate possible impacts.
- Modelação espacial de redes ecológicas regionais: contributos e propostas para a Região Norte de PortugalPublication . Martins, Mário; Castro, Paulo; Mateus, Paulo; Ferreira, Filomena; Guerra, Carlos; Azevedo, João; Honrado, João P.; Alonso, JoaquimOs intensos processos de industrialização, desenvolvimento urbano e infraestruturas, incluindo transportes e energia, assim como da intensificação da agricultura originaram fragmentação de áreas naturais, a interrupção de processos vitais e a perda significativa de biodiversidade e de serviços de ecossistemas. O desenvolvimento conceptual e operacional de redes ecológicas a diversas escalas, incluindo a escala regional, assume-se fundamental para o equilíbrio do território e promoção da qualidade de vida e do ambiente. Neste quadro, a presente investigação, desenvolvida entre instituições de investigação e da administração, visou contribuir para uma proposta conceptual e metodológica da Rede Ecológica da Região Norte de Portugal. Para tal: i) assumiram-se áreas núcleo e análise de um caminho crítico para a definição de corredores ecológicos; ii) desenvolveu-se cartografia de pressão humana e analisou-se a potencial relação de conflito dos locais de perda de conectividade com a rede proposta; iii) e comparou-se com a distribuição das alcateias de lobos identificadas para a região. Os resultados indiciam uma tendência de especialização, diminuição da multifuncionalidade territorial e fragmentação na zona litoral associada à dificuldade de estabelecer, face à antropização observada, corredores ecológicos regionais. A este nível, os Perímetros Florestais, as Terras Altas (>700 m) e o Alto Douro Vinhateiro, pela extensão e coerência da localização, demostraram ser importantes para o alargamento da rede. Em simultâneo, considera-se a necessidade de antecipar e recuperar áreas críticas de conflito entre os corredores humanos e ecológicos. Em termos futuros interessa: i) detalhar a escala e articular com as redes transfronteiriças e locais; ii) completar com dados corográficos, dinâmicas de vegetação e fauna; iii) simplificar a constituição e a gestão institucional associadas a um sistema de informação territorial de organização e partilha de dados que inclua um sistema de suporte à modelação e apoio à decisão técnico-politica.
- Population-specific phenotypic plasticity of endangered bivalves in response to extreme eventsPublication . Gomes-dos-Santos, André; Lopes-Lima, Manuel; Silva, Beatriz; Machado, André M.; Pinto, Rui; Österling, Martin; Wallerius, Magnus Lovén; Urbańska, Maria; Golski, Janusz; Runowski, Sławomir; Kaźmierczak, Sandra; Teixeira, Amilcar; Sousa, Ronaldo; Castro, L. Filipe C.; Castro, Paulo; Carvalho, Francisco; Fonseca, Elza; Froufe, ElsaFreshwater mussels are among the most endangered animal groups, highly sensitive to climate change due to their strict dependence on freshwater habitats. While freshwater mussels are often considered ecologically strict, their distribution across broad environmental gradients raises the possibility of population-specific adaptations mediated by phenotypic plasticity. This study investigates whether geographically and climatically distinct populations of two freshwater mussel species (Unio pictorum and Unio delphinus) exhibit different transcriptomic responses to prolonged heat stress and whether these responses reveal signs of local adaptation. We exposed northern and southern populations of both species to gradually increasing temperatures in controlled laboratory conditions, simulating a prolonged thermal extreme event, and RNA-seq was used to quantify differential gene expression. Results showed strong differences between northern and southern populations of the two species, both in the magnitude and functional composition of transcriptomic responses. Southern populations exhibited intense expression shifts involving classical stress pathways, heat shock proteins, detoxification (cytochrome P450s), apoptosis, and energy metabolism, while northern populations, particularly U. delphinus, showed a markedly subdued response. Notably, U. pictorum's northern population relied heavily on the cytochrome P450 family even at moderate temperatures, while the southern populations of both species activated broader proteostasis and immune responses at higher stress thresholds. These findings demonstrate clear population-specific phenotypic plasticity, shaped by environmental conditions rather than phylogenetic proximity. They underscore the need for conservation strategies to move beyond species-level management, embracing intraspecific variation as a buffer against climate impacts. As climate change accelerates, safeguarding the evolutionary potential encoded within populations, not just species, is essential to preserving biodiversity resilience.