Search results for "Threatened species"

Economic modelling as a tool to support macroalgal bloom management: a case study (Sacca di Goro, Po river delta)

2003

During the last 20, years, intensive mollusk farming has been developed in coastal waters, mostly in sheltered bays and lagoons. Often, mollusk stocks are threatened by frequent anoxic events from macroalgal blooms. Here, a decision support tool is described to select the optimal short-term strategy to control algal biomasses. Even though long-term and detailed studies of the lagoon systems are required to provide reliable, biologically based policies, we have here developed a simplified analysis that overlooks most of the ecological complexity, but explicitly includes environmental variability and uncertainty in parameter estimation in the economic assessment of the performances of differe…

Planning for the future : identifying conservation priority areas for Iberian birds under climate change

2018

[Context]: Species are expected to shift their distributions in response to global environmental changes and additional protected areas are needed to encompass the corresponding changes in the distributions of their habitats. Conservation policies are likely to become obsolete unless they integrate the potential impacts of climate and land-use change on biodiversity.

Accuracy of IKONOS for mapping benthic coral-reef habitats: a case study from the Puerto Morelos Reef National Park, Mexico

2012

International audience; Reefs are being threatened by global warming, natural disasters, and the increased pressure of the global population. These habitats are in urgent need of mapping at high resolution so that these threats can be quantified. Remote sensing can potentially provide such quantitative data. In this article, we attempt to map benthic coral-reef habitats at the Puerto Morelos Reef National Park in Yucatan Peninsula (Mexico) and to assess the accuracy of the technique in providing a baseline data for future monitoring of changes and evolution of the reef system. An IKONOS image was used in combination with checkpoint ground sampling and classified using a supervised maximum l…

Woodland key habitats in preserving polypore diversity in boreal forests: Effects of patch size, stand structure and microclimate

2016

Abstract Woodland key-habitats (WKHs) are set-asides in managed forests that are conceived to maintain specific aspects of forest biodiversity and they are widely used in Northern European countries. WKHs are often quite small (from 0.1 to a few hectares) and thus it is unclear if they can maintain biodiversity. We studied the effects of WKH size, microclimate and forest structure on species richness and composition of polypores, a group of wood-decaying fungi that has become threatened due to clear-cut forestry. The WKHs studied varied in size between 0.05 and 3.6 ha, and the control forests from 6.5 to 44.7 ha. Patch size and the volumes of logs and standing dead trees significantly affec…

2021

Climate change is having a serious impact on many ecosystems. In the summer of 2018 and 2019, around two thirds of European beech trees were damaged or killed by extreme drought. It is critical to keep these beech woods healthy, as they are central to the survival of over 6,000 other species of animals and plants. The level of damage caused by the drought varied between forests. However, not all the trees in each forest responded in the same way, with severely damaged trees often sitting next to fully healthy ones. This suggests that the genetic make-up of each tree determines how well it can adapt to drought rather than its local environment. To investigate this further, Pfenninger et al. …

Nonmodal scutes patterns in the Loggerhead Sea Turtle (Caretta caretta): a possible epigenetic effect?

2016

Eleven specimens of the threatened Loggerhead Sea Turtle (Caretta caretta (L., 1758)) were caught accidentally by fishermen in different parts of Sicily (Mediterranean Sea). Five of them showed an atypical number of carapacial and plastron scutes, making the immediate identification of the specimens as C. caretta difficult. Both genetic and epigenetic analysis were carried out on these specimens. Sequencing of a 649 bp sequence of the mitochondrial cytochrome c oxidase I (COI) gene allowed us to classify all the individuals as C. caretta. Epigenetic analysis, performed by evaluating the total level of DNA cytosine methylation, showed a reduced and significant (F = 72.65, p < 0.01) globa…

Conservation of the endangered Mediterranean tortoise Testudo hermanni hermanni: The contribution of population genetics and historical demography

2016

International audience; Estimating the genetic variation and demographic trends of species in decline is of major concern in conservation genetics. This study contributes to understanding how historical and anthropogenic factors shape the distribution of current genetic diversity in one of the most endangered reptiles in Western Europe, the Hermann's tortoise Testudo hermanni hermanni. We used 17 microsatellite loci, chosen from a pyrosequencing library specifically developed for the subspecies to genotype eight populations distributed over about 30 sample localities covering almost the entire geographic distribution of the sub-species. The population genetic results reflect a very strong g…

Corncrake conservation genetics at a European scale: the impact of biogeographical and anthropological processes

2016

Abstract Understanding patterns of genetic structure, gene flow and diversity across a species range is required to determine the genetic status and viability of small peripheral populations. This is especially crucial in species distributed across a large range where spatial heterogeneity makes it difficult to predict the distribution of genetic diversity. Although biogeographical models provide expectations of how spatially structured genetic variation may be at the range scale, human disturbance may cause strong deviations from these theoretical predictions. In this study, we investigated genetic structure and demography at a pan-European scale in the corncrake Crex crex , a grassland bi…

Snake richness predicts breeding distribution of short-toed snake eagle in central Italy.

2017

Birds of prey, as top predators, play a key role in ecosystem functioning by regulating prey populations and, by means of cascade effects, promoting biodiversity. This makes them adequate sentinels of ecosystem health. Here we analyse the relationship between the occurrence of breeding short-toed snake eagle (Circaetus gallicus) and both the richness of potential prey species and landscape characteristics by taking into account two different spatial scales (i.e. nest-site scale and landscape scale). The short-toed snake eagle offers an interesting case study for investigating the relationships between top predators, prey diversity, and habitats, because it is an extremely specialised raptor…

Evaluation of the DNA barcoding approach to develop a reference data-set for the threatened flora of Sicily

2014

The Mediterranean Basin is one of the most significantly altered World Biodiversity Hotspots with extensive habitat loss and fast genetic population erosion, for which urgent biodiversity reconnaissance and preservation actions are required. In particular, Sicily has about 600 taxa classified as threatened or near-threatened. The correct recognition and identification of such biodiversity is required for supporting further activities. The objective of this work is to assess the ability of the DNA barcoding approach to identify different taxonomic groups from a collection of the most threatened plant taxa, throughout natural Sicilian populations. The evaluation of the DNA barcoding core mark…