Navegando por Assunto "Connectivity"

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Artigo
Spatiotemporal distribution of invertebrate fauna in a mesovoid shallow substratum in iron formations
(2024-02-09) Dornellas, L.M.S.M.; da Silva, P.G.; Bichuette, M.E.; Auler, Augusto S.; Culver, David C.; Pipan, Tanja; Pires, Lorena Oliveira; Neves, Frederico de Siqueira
Iron Formations (IF) are among the most threatened environments due to the extensive mining activities. Mesovoid Shallow Substratum (MSS) in IF represents a poorly known subterranean environment and evaluating its fauna has the potential for expanding knowledge about the distribution of troglobiotic populations. We evaluated the spatiotemporal distribution of the subterranean fauna in the MSS of IF in Brazil. We sampled the MSS invertebrate fauna and described the community patterns of troglobiotic and non-troglobiotic species. A total of 22,821 individuals and 276 morphospecies belonging to two phyla were found: Annelida and Arthropoda. Acariformes, Diptera, Hymenoptera, Blattodea, and Collembola represented 92.2% of the individuals sampled. Nine troglobiotic morphospecies belonging to four groups were sampled: Araneae (1), Entomobryomorpha (6), Poduromorpha (1), and Pseudoscorpiones (1). We found a high compositional dissimilarity of troglobiotic and non-troglobiotic species in terms of spatial β-diversity (among MSS sites) and temporal β-diversity (among months). The observed spatial β-diversity of troglobiotic species sampled in the MSS is greater than that of non-troglobiotic species. The temporal variation is similar for both groups. The richness difference component contributed more to spatial and temporal β-diversity for troglobiotic species, while higher replacement values for non-troglobiotic species were observed. Average values of temporal β-diversity and the replacement component were greater for non-troglobiotic than for troglobiotic species, while the richness difference component had an opposite pattern. The spatiotemporal β-diversity patterns suggest a medium-to-low connectivity of invertebrate populations that colonize the MSS, favoring the adoption of strategies for conserving broader areas in the context of IF.
Artigo
The Interplay of Homing and Dispersal in Green Turtles
(2012-10-08) Naro-Maciel, E.; Bondioli, Ana Cristina Vigliar; Martin, Meredith; Almeida, A. P.; Baptistotte, C.; Bellini, C.; Marcovaldi, M. A.; Santos, A. J. B.; Amato, G.
Current understanding of spatial ecology is insufficient in many threatened marine species, failing to provide a solid basis for conservation and management. To address this issue for globally endangered green turtles, we investigated their population distribution by sequencing a mitochondrial control region segment from the Rocas Atoll courtship area (n = 30 males) and four feeding grounds (FGs) in Brazil (n = 397), and compared our findings to published data (nnesting = 1205; nfeeding = 1587). At Rocas Atoll, the first Atlantic courtship area sequenced to date, we found males were differentiated from local juveniles but not from nesting females. In combination with tag data, this indicates possible male philopatry. The most common haplotypes detected at the study sites were CMA-08 and CMA-05, and significant temporal variation was not revealed. Although feeding grounds were differentiated overall, intra-regional structure was less pronounced. Ascension was the primary natal source of the study FGs, with Surinam and Trindade as secondary sources. The study clarified the primary connectivity between Trindade and Brazil. Possible linkages to African populations were considered, but there was insufficient resolution to con clusively determine this connection. The distribution of FG haplotype lineages was nonrandom and indicative of regional clustering. The study investigated impacts of population size, geographic distance, ocean currents, and juvenile natal homing on connectivity, addressed calls for increased genetic sampling in the southwestern Atlantic, and provided data important for conservation of globally endangered green turtles.
Texto publicado em revista
The Interplay of Homing and Dispersal in Green Turtles: A Focus on the Southwestern Atlantic
(Journal of Heredity, 2012-10-08) NARO-MACIEL, E; BONDIOLI, A.C.V; MARTIN, M; ALMEIDA, A.P; BAPTISTOTTE, C; BELLINI, C; MARCOVALDI, M.A; SANTOS, A.J.B; AMATO, G
Current understanding of spatial ecology is insufficient in many threatened marine species, failing to provide a solid basis for conservation and management. To address this issue for globally endangered green turtles, we investigated their population distribution by sequencing a mitochondrial control region segment from the Rocas Atoll courtship area (n = 30 males) and four feeding grounds (FGs) in Brazil (n = 397), and compared our findings to published data (nnesting = 1205; nfeeding = 1587). At Rocas Atoll, the first Atlantic courtship area sequenced to date, we found males were differentiated from local juveniles but not from nesting females. In combination with tag data, this indicates possible male philopatry. The most common haplotypes detected at the study sites were CMA-08 and CMA-05, and significant temporal variation was not revealed. Although feeding grounds were differentiated overall, intra-regional structure was less pronounced. Ascension was the primary natal source of the study FGs, with Surinam and Trindade as secondary sources. The study clarified the primary connectivity between Trindade and Brazil. Possible linkages to African populations were considered, but there was insufficient resolution to conclusively determine this connection. The distribution of FG haplotype lineages was nonrandom and indicative of regional clustering. The study investigated impacts of population size, geographic distance, ocean currents, and juvenile natal homing on connectivity, addressed calls for increased genetic sampling in the southwestern Atlantic, and provided data important for conservation of globally endangered green turtles.