15 research outputs found
Notes sur le taux intrinsèque d’accroissement naturel de la bruche de l’arachide Caryedon gonagra (f ab.) (Coleoptera, bruchidae)
L’influence des facteurs écologiques sur le degré de variation du taux intrinsèque d’accroissement naturel (r) d’une population et du taux net de reproduction (R„) est illustrée par des expé riences sur la biologie de la Bruche de l’Arachide, Caryedon gonagra (Fab.).The influence of ecological parameters on the variation of the intrinsic rate of natural increase (r) and the net reproduction rate (Ra) is exemplified by some experiments on the biology of the Groundnut beetle, Caryedon gonagra (Fab.)
Comparative assessment of climate change and its impacts on three coastal aquifers in the Mediterranean
A comparative study on climate change and its impacts on coastal aquifers is performed for three Mediterranean areas. Common climate scenarios are developed for these areas using the ENSEMBLES projections that consider the A1b scenario. Temperature and precipitation data of three climate models are bias corrected with two different methods for a historic reference period, after which scenarios are created for 2020-2050 and 2069-2099 and used to calculate aquifer recharge for these periods based on two soil water budget methods. These multiple combinations of models and methods allow incorporating a level of uncertainty into the results. Groundwater flow models are developed for the three sites and then used to integrate future scenarios for three different parameters: (1) recharge, (2) crop water demand, and (3) sea level rise. Short-term predictions are marked by large ranges of predicted changes in recharge, only showing a consistent decrease at the Spanish site (mean 23 %), particularly due to a reduction in autumn rainfall. The latter is also expected to occur at the Portuguese site, resulting in a longer dry period. More frequent droughts are predicted at the Portuguese and Moroccan sites, but cannot be proven for the Spanish site. Toward the end of the century, results indicate a significant decrease (mean >25 %) in recharge in all areas, though most pronounced at the Portuguese site in absolute terms (mean 134 mm/year) and the Moroccan site in relative terms (mean 47 %). The models further predict a steady increase in crop water demand, causing 15-20 % additional evapotranspiration until 2100. Scenario modeling of groundwater flow shows its response to the predicted decreases in recharge and increases in pumping rates, with strongly reduced outflow into the coastal wetlands, whereas changes due to sea level rise are negligible
New insights into the systematics of North Atlantic Gaidropsarus (Gadiformes, Gadidae): flagging synonymies and hidden diversity
Gaidropsarus Rafinesque, 1810 is a genus of marine fishes, commonly known as rocklings, comprising 14 living species and showing a high ecological diversity from the intertidal zone to the deep sea. The systematics of this group has been controversial due to a general lack of representative specimens and the conservative morphology exhibited. A multidisciplinary approach combining the analysis of meristic data and the DNA barcode standard was applied in a species delimitation approach. Individuals representing eight valid and three unnamed species were collected, morphologically identified and archived in several museum collections. Comparison of DNA sequences shows complex results, furthering the idea of the difficult identification of specimens based on traditional taxonomy. DNA barcoding supports synonymies, like G. biscayensis–G. macrophthalmus and G. guttatus–G. mediterraneus, agreeing with the extensive overlaps observed in the meristic variables analysed and suggesting a reduction in the number of species. Genetic distances showed pairs of closely related species like G. granti–G. vulgaris and G. argentatus–G. ensis, the latter being only distinguished by one main distinctive character. Four deep-water specimens, morphologically classified only to the genus level, constituted three independent taxa apart from the ones present in this study and with no barcode matches in the repository databases. They could represent new records for the North Atlantic or unknown species of this genus. The results obtained show that more studies will be necessary to solve the systematics of this branch of the Gadiformes
The EU Butterfly Indicator for Grassland species: 1990-2017. Technical report
The EU Grassland Butterfly Indicator is one of the indicators of the status of biodiversity in the European Union. It is an abundance indicator based on data recording the population trends of seventeen butterfly species in 16 (see below) EU countries. This report presents the seventh version of this indicator now covering 28 years. At the Convention on Biological Diversity meeting in Nagoya (Japan) the Strategic Plan for Biodiversity 2011– 2020 was adopted. It proposed five goals and 20 “Aichi” biodiversity targets. In line with this plan a new EU biodiversity strategy was adopted by the European Commission in May 2011. This provided a framework for the EU to meet its own biodiversity objectives and its global commitments as a party to the CBD. The Headline Target is to halt the loss of biodiversity and the degradation of ecosystem services in the EU by 2020, and restore them, in so far as feasible, while stepping up the EU contribution to averting global biodiversity loss. Under Target 3A the EU is committed to increase the contribution of agriculture to biodiversity recovery. Europe now has one year left to intensify action to achieve this. The EU biodiversity strategy includes the development of a coherent framework for monitoring, assessing and reporting on progress in implementing actions. Such a framework is needed to link existing biodiversity data and knowledge systems with the strategy, to help assess achievement of the goals and to streamline EU and global monitoring, reporting and review obligations. Some of the EU biodiversity indicators provide specific measurements and trends on genetic, species and ecosystem/landscape diversity, but many have a more indirect link to biodiversity. Very few have been established specifically to assess biodiversity. The status indicators on species only cover birds, bats and butterflies, since these are the only taxa/species groups for which harmonized European monitoring data are available (EEA, 2012). For the EU Grassland Butterfly Indicator the trends of seventeen widespread and characteristic grassland butterflies were assessed in 16 countries in the European Union. This technical report gives an overview of the method and results, and presents the indicator
Butterfly indicators 1990-2018. Technical report
There is mounting evidence of widespread declines in the diversity and abundance of insects from across the globe (Sanchez-Bayo and Wyckhuys 2019, Seibold et al. 2019, van Klink et al. 2020, Wagner 2020). This gives a stark warning for the perilous state of biodiversity (Diaz et al. 2019), and demonstrates that addressing the gap in knowledge of the status of insects is vital (Cardoso et al. 2020, Samways et al. 2020). Insects are estimated to comprise more than half of all described species and are a dominant component of biodiversity in most ecosystems (Bar-On et al. 2018). Insects also provide a crucial role in the functioning of ecosystems. They are not only related to the supply of many ecosystem services such as pollination, biological control, soil fertility regulation and diverse cultural ecosystem services but also to disservices such as damage to crops and spread of diseases to livestock and humans (Gutierrez-Arellano and Mulligan 2018, Noriega et al. 2018). There is a pressing need to assess the status of insects to set and evaluate conservation targets. At the Convention on Biological Diversity (CBD) meeting in Nagoya (Japan), the Strategic Plan for Biodiversity 2011-2020 was adopted. It proposed five goals and 20 "Aichi" biodiversity targets. In line with this plan, a new EU biodiversity strategy was adopted by the European Commission in May 2011. This strategy provided a framework for the EU to meet its biodiversity targets and global commitments as a party to the CBD. The Headline Target in the existing EU Biodiversity Strategy 2020 is to halt the loss of biodiversity and the degradation of ecosystem services in the EU by 2020, and restore them, in so far as feasible, while stepping up the EU contribution to averting global biodiversity loss. Under Target 3A the EU is committed to increasing the contribution of agriculture to biodiversity recovery. Further, the EU Biodiversity Strategy 2030 includes the development of a coherent framework for monitoring, assessing and reporting on progress in implementing actions. Such a framework is needed to link existing biodiversity data and knowledge systems with the strategy, to help assess achievement of the goals and to streamline EU and global monitoring, reporting and review obligations. Some of the EU biodiversity indicators provide specific measurements and trends on genetic, species and ecosystem/landscape diversity, but many have a more indirect link to biodiversity. Very few have been explicitly established to assess biodiversity. The status indicators on species only cover birds, bats and butterflies, since these are the only taxa/species groups for which reasonably harmonized European monitoring data are available (EEA, 2012). This technical report builds upon previous technical reports for the EU Grassland Butterfly Indicator (e.g. van Swaay et al., 2019) to: 1. Describe a new approach for assessing butterfly trends and developing indicators of European butterflies; 2. Give an overview of the main results, and present a range of butterfly indicators; 3. Discuss the next steps to improve butterfly indicators for Europe. Butterflies are ideal biological indicators: they are well-documented, measurable, sensitive to environmental change, occur in a wide range of habitat types, represent many other insects, and are popular with the public because of their beauty. Field monitoring is essential to assess changes in their abundance. Indicators based on butterfly monitoring data are valuable to understand the state of the environment and help evaluate policy and implementation. Trained volunteers are a cost-effective way of gathering robust data on butterflies, more so when supported by informative materials and efficient online recording