Browsing by Issue Date, starting with "2024-08"
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- The persistence of gender pay and employment gaps in European countriesPublication . Afonso, António; Blanco-Arana, M. CarmenThe gender pay gap and the gender gap in employment remains persistent in Europe despite the basic assertion of gender equality under EU law. We assess the factors that influence the gender pay gap and gender employment gap across European countries. Therefore, we use an unbalanced panel of 31 European countries over the period 2000-2022, and estimate a system generalized method of moment model (GMM). The main conclusions confirm that tertiary education significantly reduces gender pay gap and part-time and temporary contracts significantly increase this gap. Moreover, part-time reduces significantly gender employment gap. Gross Domestic Product (GDP) per capita does not affect these gaps and the Global Financial Crisis (GFC) saw a narrowing of the gender pay and employment gaps in European countries. The results are robust when using a fixed effects (FE) model.
- Network-Based analysis of EU emissions trading schemePublication . Paolella, Beatrice Federica; Araújo, TanyaThe European Union Emissions Trading Scheme (EU ETS) has been instrumental in mitigating carbon dioxide (CO2) emissions across Europe since its initiation on January 1, 2005. CO2 has emerged as a traded commodity in the EU ETS, governed by market fundamentals similar to those in other global commodity markets. The interplay of supply and demand, driven by the allocation of allowances, plays thus a crucial role. Here, using real data, we developed networks of EU ETS to model exchanges of allowances between EU countries. Our results provide new insights into the topological structure of trading from 2005-2020. Combining the results from centrality measures, clustering and modularity, the EU ETS networks can be seen in the transition from a structure with few clusters to a structure characterized by numerous clusters organized around new nodes with acquired centrality.
- The Marine Macroalgae Collection from Herbarium João de Carvalho e Vasconcellos (LISI)—140 Years of HistoryPublication . Canilho Santos, João; Paes, Paula; Arsénio, Pedro; Figueira, Rui; Costa, José Carlos; Lopes, Margarida Dionísio; Cotrim, HC; Espírito-Santo, DalilaHerbaria phycological collections have approximately one million 700 thousand specimens preserved in European herbaria, a significantly lower number when compared to vascular plants, due to factors such as greater sampling difficulty and fewer specialists. Several studies report that coastal systems have undergone dramatic ecological changes in the last 150 years, with macroalgae being a particularly affected group. Thus, macroalgal herbaria are essential sources for the study and conservation of this biodiversity, as well as a pillar that responds to several ecological questions. Despite having a large coastline, Portugal’s phycological collections are scarce, poorly developed, and practically inaccessible digitally. In 2021/2022, all the phycological specimens present at LISI were the focus of this exploratory project whose objective was to catalog them, taxonomically review the specimens and place them at the service of the scientific community through the incorporation of digitized vouchers into online databases. Three marine collections were constituted and studied, accounting for a total of 852 vouchers and more than 1800 specimens, being the Portuguese Marine Macroalgae Collection, the oldest digitized phycological collection available in Portugal. This project provides an opportunity for other educational institutions to embrace their long-neglected collections as well.
- Cymbopogon citratus Allelochemical Volatiles as Potential Biopesticides against the Pinewood NematodePublication . Faria, Jorge M. S.; Barbosa, PedroTraditional pesticides are based on toxic compounds that can reduce biodiversity, degrade the environment, and contribute to less healthy living. Plant allelochemicals can provide more environmentally friendly and sustainable alternatives. Essential oils (EOs) are complex mixtures of plant secondary metabolites that show strong biological activities. In the present study, the EOs of Cymbopogon citratus were screened for activity against the pinewood nematode (PWN), the causal agent of pine wilt disease. To understand their nematicidal properties, EOs were fractioned into hydrocarbon molecules and oxygen-containing compounds, and their main compounds were acquired and tested separately against the PWN. The EO oxygen-containing molecules fraction was highly active against the PWN (EC50 = 0.279 µL/mL), with citral and geraniol showing higher activities (EC50 = 0.266 and 0.341 µL/mL, respectively) than emamectin benzoate (EC50 = 0.364 µL/mL), a traditional nematicide used against the PWN. These compounds were additionally reported to be less toxic to non-target organisms (fish, invertebrates, and algae) and safer to human health (with higher reported toxicity thresholds) and predicted to exert fewer environmental impacts than traditional nematicides. Resorting to approved natural compounds can quickly leverage the development of sustainable alternatives to traditional nematicides.
- Hybridization in the Anthropocene – how pollution and climate change disrupt mate selection in freshwater fishPublication . Ramirez‐Duarte, Wilson F.; Moran, Benjamin M.; Powell, Daniel L.; Bank, Claudia; Sousa, Vitor C; Rosenthal, Gil G.; Schumer, Molly; Rochman, Chelsea M.Chemical pollutants and/or climate change have the potential to break down reproductive barriers between species and facilitate hybridization. Hybrid zones may arise in response to environmental gradients and secondary contact between formerly allopatric populations, or due to the introduction of non-native species. In freshwater ecosystems, field observations indicate that changes in water quality and chemistry, due to pollution and climate change, are correlated with an increased frequency of hybridization. Physical and chemical disturbances of water quality can alter the sensory environment, thereby affecting chemical and visual communication among fish. Moreover, multiple chemical compounds (e.g. pharmaceuticals, metals, pesticides, and industrial contaminants) may impair fish physiology, potentially affecting phenotypic traits relevant for mate selection (e.g. pheromone production, courtship, and coloration). Although warming waters have led to documented range shifts, and chemical pollution is ubiquitous in freshwater ecosystems, few studies have tested hypotheses about how these stressors may facilitate hybridization and what this means for biodiversity and species conservation. Through a systematic literature review across disciplines (i.e. ecotoxicology and evolutionary biology), we evaluate the biological interactions, toxic mechanisms, and roles of physical and chemical environmental stressors (i.e. chemical pollution and climate change) in disrupting mate preferences and inducing interspecific hybridization in freshwater fish. Our study indicates that climate change-driven changes in water quality and chemical pollution may impact visual and chemical communication crucial for mate choice and thus could facilitate hybridization among fishes in freshwater ecosystems. To inform future studies and conservation management, we emphasize the importance of further research to identify the chemical and physical stressors affecting mate choice, understand the mechanisms behind these interactions, determine the concentrations at which they occur, and assess their impact on individuals, populations, species, and biological diversity in the Anthropocene.
- Mate-choice copying accelerates species range expansionPublication . Sapage, Manuel; Santos, Mauro; Matos, Margarida; Schlupp, Ingo; Varela, Susana A. M.Mate-choice copying is a type of social learning in which females can change their mate preference after observing the choice of others. This behaviour can potentially affect population evolution and ecology, namely through increased dispersal and reduced local adaptation. Here, we simulated the effects of mate-choice copying in populations expanding across an environmental gradient to understand whether it can accelerate or retard the expansion process. Two mate-choice copying strategies were used: (i) when females target a single individual and (ii) when females target similar individuals. We also simulated cases where the male trait singled out by females with mate choice maps perfectly onto his genotype or is influenced by genotype-by-environment interactions. These rules have different effects on the results. When a trait is determined by genotype alone, populations where copier females target all similar males expand faster and the number of potential copiers increased. However, when preference is determined by genotype-by-environment interactions, populations where copier females target a single male had higher dispersal and also expand faster, but the potential number of copiers decreases. The results show that mate-choice copying can accelerate the expansion process, although its adaptiveness depends on the information animals use in different contexts.
- Effects of livestock on arthropod biodiversity in Iberian holm oak savannas revealed by metabarcodingPublication . Canelo, Tara; Marquina, Daniel; Chozas, Sergio; Bergsten, Johannes; Gaytán, Álvaro; Pérez-Izquierdo, Carlos; Bonal, RaúlIncreasing food production while avoiding negative impacts on biodiversity constitutes one of the main chal- lenges of our time. Traditional silvopastoral systems like Iberian oak savannas (“dehesas”) set an example, where free-range livestock has been reared for centuries while preserving a high natural value. Nevertheless, factors decreasing productivity need to be addressed, one being acorn losses provoked by pest insects. An increased and focalized grazing by livestock on infested acorns would kill the larvae inside and decrease pest numbers, but increased livestock densities could have undesired side effects on ground arthropod communities as a whole. We designed an experimental setup including areas under trees with livestock exclosures of different ages (short- term: 1-year exclusion, long-term: 10-year exclusion), along with controls (continuous grazing), using DNA metabarcoding (mitochondrial markers COI and 16S) to rapidly assess arthropod communities’ composition. Livestock removal quickly increased grass cover and arthropod taxonomic richness and diversity, which was already higher in short-term (1-year exclosures) than beneath the canopies of control trees. Interestingly, arthropod diversity was not highest at long-term exclosures (≥10 years), although their community composition was the most distinct. Also, regardless of treatment, we found that functional diversity strongly correlated with the vegetation structure, being higher at trees beneath which there was higher grass cover and taller herbs. Overall, the taxonomic diversity peak at short term exclosures would support the intermediate disturbance hypothesis, which relates it with the higher microhabitat heterogeneity at moderately disturbed areas. Thus, we propose a rotatory livestock management in dehesas: plots with increased grazing should co-exist with temporal short-term exclosures. Ideally, a few long-term excluded areas should be also kept for the singularity of their arthropod communities. This strategy would make possible the combination of biological pest control and arthropod conservation in Iberian dehesas.
- New Races of Hemileia vastatrix Detected in Peruvian Coffee FieldsPublication . Julca-Otiniano, Alberto; Alvarado-Huamán, Leonel; Castro-Cepero, Viviana; Borjas-Ventura, Ricardo; Gómez-Pando, Luz; Pereira, Ana Paula; Nielen, Stephan; Ingelbrecht, Ivan; Silva, Maria do Céu; Varzea, VitorCoffee leaf rust (CLR), a fungal disease caused by Hemileia vastatrix, represents Peru’s most significant threat to coffee production. The CLR epidemic (2012–2013) led Peru to implement an emergency plan under which coffee plantations underwent renewal using rust-resistant varieties derived from a Timor hybrid (HDT; Coffea arabica × canephora hybrid) like Catimors. Nevertheless, new pathogenic rust races capable of infecting these varieties have been recorded. Eighteen rust samples from coffee genotypes, such as Caturra, Typica, and Catimor, were collected in various Peru- vian regions and sent to CIFC/ISA/UL (Centro de Investigação das Ferrugens do Cafeeiro/Instituto Superior de Agronomia/Universidade de Lisboa) in Portugal for race characterization. Assessing the virulence spectra of rust samples on a set of 27 coffee differentials resulted in the identification of 5 known and 2 new races. This study emphasizes the significance of conducting surveys on the diversity of H. vastatrix races in Peru for effective disease management. Moreover, Catimor lines, widely cultivated in coffee-growing countries, are susceptible to the 2 new races and to races XXXIV and XXXV identified in this study. Thus, coffee farmers need to know the resistance spectrum of new varieties before introducing them to CLR-affected regions
- Water requirements and crop coefficients of edible, spicy and medicinal herbs and vegetables; a review aimed at supporting plant and water managementPublication . Pereira, Luis S.; Mota, Mariana; Raziei, Tayeb; Paredes, PaulaTraditional edible, spicy and medicinal herbs rarely are included in studies on water requirements, evapotranspiration and crop coefficients (Kc) of vegetable crops. While the latter refer to large markets and are used worldwide, the former has small and specialized markets. They are very rarely grown in large farms but rather in small farming systems, or just harvested in the wild, and related evapotranspiration (ET) studies are less frequently considered in main journals focused on water management in agriculture. However, there is abundant bibliography covering traditional edible, spicy and medicinal herbs. Following the partition adopted in recently published articles on K c values, such crops are grouped according to the main part of the plant purposefully harvested: roots, rhizomes and tubers; leaves and flowers; fruits, pods and seeds. Since we focused on Kc and not on the products, and because many crops have simultaneously two usages such as spicy and medicinal, main uses are presented to characterize the crop. Interestingly, the reviewed crop coefficients have values quite similar to those of the more common and popular vegetable crops. The single crop coefficients reviewed, and referring to the initial, mid-season and end-season periods, are tabulated according to the referred groups. In addition, aiming at their use in water management and modelling, crop heights, root depths, fractions of ground cover and fractions of soil water extraction without stress are also tabulated. In conclusion, this review aimed at successfully provide K c values to be used for computing crop evapotranspiration for irrigation scheduling and crop water management of the referred herbs and vegetables.
- Widespread experimental evidence of Allee effects in insects: a meta-analysisPublication . Branco, Manuela; Dokhelar, Théo; Brockerhoff, Eckehard G.; Liebhold, Andrew M.; Jactel, HervéDuring the last two decades there has been growing recognition of the importance of Allee effects in population dynamics and applied ecology. The Allee effect, that is decreased fitness at lower population densities, has been recognized as potentially playing an important role in the conservation of endangered species, in the practice of biological control, and the eradication of invasive species. Although a number of theoretical studies have been devoted to the role of Allee effects in the population dynamics of insects and other terrestrial arthropods, experimental evidence documenting Allee effects is still scarce. Here, we reviewed the literature reporting on density-dependent relationships in low-density populations and conducted a meta-analysis of 191 case studies to identify the occurrence of Allee effects and associated species traits. Allee effects are not rare in terrestrial arthropods, as they were reported in 47% of the cases we reviewed, comprising 46 out of 68 species. Ample examples exist for both demographic Allee effects (28 out of 74 cases cases), and component Allee effects (61 out of 117 cases). Insufficient mating success, cooperative feeding, and enemy escape were the three main mechanisms associated with Allee effects in terrestrial arthropods. Insufficient reproductive success was the mechanism with the highest proportion of related Allee effects (71%). Voltinism and host specialization were common species traits behind demographic Allee effects. Host specialists with univoltine life cycles tended to have stronger Allee effects. The high frequency of Allee effects in terrestrial arthropods reported here and the identified mechanisms behind them have important implications for the selection of management strategies.