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Povzetek: As a result of improper management, plastics such as drinking cups are accumulating in environmental compartments worldwide, impacting biodiversity and ecosystem services. The goal of this study is to analyze and compare potential environmental impacts of disposable cups made of Polypropylene and Polylactic acid with the help of a cradle-to-grave life cycle assessment, including impacts related to the littering of these cups. Plastic pollution impacts are calculated based on the products' persistence in the environment, comparing the results of our own experiment to literature data. As an indication of the possible adverse health effects of Polypropylene and Polylactic acid, a toxicity test of the chemical mixtures migrating from the cups is conducted. Overall, the cups made of Polypropylene show lower environmental impacts compared to those made of Polylactic acid when the experimentally determined degradation rates are used. Nevertheless, regarding toxicity of the chemical migrates, the cup made of Polylactic acid performs better than the one made of Polypropylene. Considering all impact categories, there is no overall improvement in environmental impacts of producing the cup from Polylactic acid instead of Polypropylene. Our results indicate the importance of using degradation data measured specifically for the assessed product. Methodologically, we demonstrate a possible integration of life cycle assessment and safe-and-sustainable-by-design scoring. Further development of the plastic pollution impact category is needed to integrate effects on the terrestrial environment.
Ključne besede: degradation, accelerated weathering, product environmental footprint, life cycle assessment, plastic pollution, toxicity
Objavljeno v DiRROS: 27.05.2025; Ogledov: 229; Prenosov: 152
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Ključne besede: marine strategy, eutrophication, good environmental status, methodology
Objavljeno v DiRROS: 23.04.2025; Ogledov: 242; Prenosov: 0
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Povzetek: Marginal and peripheral populations are important for biodiversity conservation. Their original situation in a species’ geographic and ecological space often confers them genetic diversity and traits of high adaptive value. Yet theoretical hypotheses related to marginality are difficult to test because of confounding factors that influence marginality, namely environment, geography, and history. There is an urgent need to develop metrics to disentangle these confounding factors. We designed nine quantitative indices of marginality and peripherality that define where margins lie within species distributions, from a geographical, an environmental and a historical perspective. Using the distribution maps of eight European forest tree species, we assessed whether these indices were idiosyncratic or whether they conveyed redundant information. Using a database on marginal and peripheral populations based on expert knowledge, we assessed the capacity of the indices to predict the marginality status of a population. There was no consistent pattern of correlation between indices across species, confirming that the indices conveyed different information related to the specific geometry of the species distributions. Contrasting with this heterogeneity of correlation patterns across species, the relative importance of the indices to predict the marginality status of populations was consistent across species. However, there was still a significant country effect in the marginality status, showing a variation in expert opinion of marginality vis-á-vis the species distribution. The marginality indices that we developed are entirely based on distribution maps and can be used for any species. They pave the way for testing hypotheses related to marginality and peripherality, with important implications in quantitative ecology, genetics, and biodiversity conservation.
Ključne besede: centre-periphery hypothesis, environmental indices, geographical indices, migration indices, marginal populations, peripheral populations, in situ genetic conservation
Objavljeno v DiRROS: 07.04.2025; Ogledov: 217; Prenosov: 117
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Povzetek: Sexual size dimorphism theory predicts biased operational sex ratios (OSRs) and an uneven distribution of males among certain females. We studied this phenomenon through a field census of the giant wood spider Nephila pilipes (family Nephilidae) in Singapore, a species where females are, on average, 6.9 times larger than males. Specifically, we tested two hypotheses concerning male distribution, given their tendency to aggregate in certain female webs. The optimal female size hypothesis predicts that males would predominantly occupy webs of intermediate-sized females. The web clustering hypothesis posits that more males would be found in webs closer together compared to those farther apart. Our snapshot census revealed a female-biased OSR (females: males = 1.85) with an uneven distribution of males in female webs. Most males were found in webs of intermediate-sized females aligning with the optimal female size hypothesis. Proximity among female webs was indicative of male presence, lending support to the web clustering hypothesis. While our study's limited sample size warrants caution, we conclude that in N. pilipes, male occupation of female webs is facilitated by the clustering of webs, and males prefer to cohabit with optimally sized, receptive females.
Ključne besede: sexual size dimorphism, operational sex ratios (OSRs), male distribution, optimal female size hypothesis, web clustering hypothesis, female-biased OSR, intermediate-sized females, proximity of webs, male aggregation, arachnology, behavioral ecology, environmental zoology
Objavljeno v DiRROS: 12.02.2025; Ogledov: 296; Prenosov: 152
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Povzetek: DNA metabarcoding of benthic diatoms has been successfully applied for biomonitoring at the national scale and can now be considered technically ready for routine application. However, protocols and methods still vary between and within countries, limiting their transferability and the comparability of results. In order to overcome this, routine use of DNA metabarcoding for diatom biomonitoring requires knowledge of the sources of variability introduced by the different steps of the procedure. Here, we examine how elements of routine procedures contribute to variability between European laboratories. A set of four experiments were performed focusing on DNA extraction and PCR amplification steps to evaluate their reproducibility between different laboratories and the variability introduced by different protocols currently applied by the scientific community. Under the guidance of a reference laboratory, 17 participants from 14 countries performed DNA extraction and PCR amplification in parallel, using the same fixed protocol and their own choice of protocol. Experiments were performed by each participant on a set of standardised DNA and biofilm samples (river, lake and mock community) to investigate potential systematic and random errors. Our results revealed the successful transferability of a protocol amongst labs and a highly similar and consistent ecological assessment outcome obtained regardless of the protocols used by each participant. We propose an “all for one but prove them all” strategy, suggesting that distinct protocols can be used within the scientific community, as long as their consistency is be proven by following minimum standard requirements.
Ključne besede: cross-laboratory experiment, DNA-based approach, ecological status assessment, intercalibration, standardisation, environmental science, biomonitoring, DNA metabarcoding, benthic diatoms
Objavljeno v DiRROS: 17.01.2025; Ogledov: 293; Prenosov: 185
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