Os efeitos de regimes distintos de herbicidas em artrópodes de solo

Mestrado em Ecologia, Biodiversidade e Gestão de EcossistemasAs práticas agrícolas têm sido associadas a perdas em larga escala a nível da biodiversidade. No entanto, elementos como as margens dos campos, são con-siderados importantes e com potencial para diminuir os impactes da agricultura ao promover fontes de alimento e refúgio. No entanto, os pesticidas e em parti-cular os herbicidas podem afectar estas áreas e provocar impactes nas comu-nidades que dependem destas estruturas. Devido à sua sensibilidade a pertur-bações, os artrópodes são um grupo ideal para avaliar os impactes de pestici-das nos sistemas agrícolas. Para além disto têm um papel fundamental nas teias tróficas, constituindo a maior fonte de alimento para muitos vertebrados que habitam nestes ambientes, como a espécie de lagartixa Podarcis bocagei. Neste estudo, avaliou-se o efeito da utilização de herbicidas nas comunidades de artrópodes de margens agrícolas, com recurso ao método de captura por armadilha de queda e a um método para estimar rapidamente a biodiversidade, a identificação a um nível taxonómico elevado. O estudo focou-se nas diferen-ças entre margens de campos com e sem herbicidas em duas estações, prima-vera e outono. A abundância, riqueza de grupos e a composição de guildas tróficas foram determinadas, assim como a abundância e tamanho dos artrópo-des presas de Podarcis bocagei, a lagartixa mais comum na área. Relativamente às diferenças encontradas entre os campos, destaca-se a ausência de um padrão negativo provocado pelos herbicidas. Na primavera os parâmetros avaliados foram, geralmente, mais elevados nas margens agrícolas tratadas. No outono o padrão que surgiu foi distinto, com um dos campos não expostos exibindo valores mais elevados para os parâmetros avaliados, sendo as diferenças entre os campos mais ténues. Os resultados parecem indicar que alguns dos campos são mais favoráveis às populações de artrópodes, assim como às populações de lacertídeos. No entanto, em geral o tratamento com herbicidas não foi suficiente para explicar as variações encontradas nas comunidades de artrópodes. Outros factores não avaliados, como a estrutura da paisagem e do habitat e a composição florística podem ter contribuído para as diferenças encontradas.Since the advent of agricultural intensification that agricultural practices such as pesticide usage have become associated with large scale biodiversity losses. However, semi-natural landscape elements associated, such as field margins, are thought to benefit biodiversity and lessen the damaging effects of agricul-ture by providing sources of food and refuges. Nevertheless, Pesticides, and herbicides in particular may also affect these areas and consequently impact the communities that depend on these structures. Because of high diversity and sensitivity to disturbance, arthropods are ideal animals to assess impacts of pesticides in these ecosystems. Furthermore, they play essential roles in trophic webs, constituting the major diet components for many vertebrate spe-cies that inhabit these ecosystems, such as the lizard Podarcis bocagei. In this study the effects of herbicides on arthropod communities of field margins were estimated, using pitfall traps and identification to a higher taxonomic level as a rapid assessment method of biodiversity. The study focused on the differ-ences between herbicide treated and non-treated margins in two distinct sea-sons, spring and autumn, being abundance, group richness, guild composition, abundance and size of prey items of Podarcis bocagei, the most common lizard in the area, determined for all fields. Differences were found between fields, but no clear negative effects were evi-denced as a consequence of herbicidal treatment. In spring, margins of ex-posed fields generally exhibited higher values for the assessed parameters, while in autumn, a distinct pattern arose, with fewer differences found between communities. Results seem to indicate that some of the fields may be more favourable to arthropod populations, as well as lacertid populations, but overall, herbicide treatment was not sufficient to explain the variation found in arthropod commu-nities. Other unassessed factors such as landscape and habitat structure and plant community composition could be contributing to the differences found

Composition and seasonal variation of epigeic arthropods in field margins of NW Portugal

Field margins act as shelters for different arthropod taxa in agricultural fields. Several factors may promote seasonal changes in arthropod communities, especially in regions with marked seasonality, such as Mediterranean areas. Epigeic arthropods were sampled from the margins of fields located in northwestern Portugal during 2 contrasting seasons, spring and autumn. Organisms were identified to family or order level and seasonal variation in arthropod communities was evaluated. Abundance, group richness, and feeding guild parameters were affected by sampling season, with both abundance and richness being higher in spring. Of the groups captured in both seasons, most evidenced either higher abundance in spring or similar abundance between seasons. Ants constituted one of the most abundant trophic guilds in spring but one of the least captured in autumn, while catches of parasitoids and parasites were not affected by sampling season. Results indicate that the higher taxa approach is useful to distinguish seasonally distinct communities

Avaliação ecotoxicológica de PAHs utilizando a planária de água doce, Girardia tigrina

Freshwater planarians are animals that possess a set of features that has made them pivotal for research areas such as stem cell research, neurophar-macology, or ageing research. The appeal of these animals has stemmed from features such as the existence of adult stem cells distributed over their bodies, the presence of a simple brain sharing similarities with the vertebrate nervous system, or their apparent lack of ageing. The interest in freshwater planarians as experimental animals has spread to ecotoxicity testing, given features such as easy maintenance in laboratory setting, their sensitivity to environmental contaminants, and also the range of effects that can be evaluated in response to contaminants, such as teratogenicity, carcinogenicity, reproductive and be-havioural toxicity or neurotoxicity. Their predatory nature offers yet another interesting opportunity to include them in multi-species tests as epibenthic in-vertebrate predators. In the context of exploring the sensitivity of freshwater planarian endpoints to environmental contaminants, the present work used polycyclic aromatic hydrocarbons (PAHs) as model compounds. PAHs are ubiquitous contaminants in the environment, given the multitude of natural and anthropogenic sources and their ability to be transported over long distances through the air. As a major contaminant class in the environment, the risk as-sessment of PAHs has been challenging, given the array of metabolizing abili-ties among invertebrates, as well as the multitude of effects these compounds can elicit. For some invertebrate groups, such as freshwater planarians, there is virtually no (eco)toxicological information. With the ultimate goal of exploring freshwater planarians in the context of ecotoxicological research, this work used the freshwater Girardia tigrina as experimental animal and three PAHs with distinct number of aromatic rings, the 3-, 4- and 5-ringed phenanthrene, pyrene and benzo[a]pyrene, respectively. Several specific objectives were ad-dressed: development of novel planarian bioassays, evaluation of PAH toxicity potential accumulation in G. tigrina under different exposure scenarios. Along 6 experimental chapters, experimental protocols were refined and, more specifi-cally, a feeding protocol was developed in accordance with the specific features of G. tigrina. This freshwater planarian was also shown to be sensitive to PAHs, with mortality, disintegration of tissues, regeneration delays, behavioural impairments, biochemical changes, decreases in reproductive output and de-creased newborn fitness being observed: The severity of effects was well relat-ed with the concentration-dependent increase of PAH-type compounds in pla-narian tissues. However, despite chemical similarities, each PAH elicited differ-ent effects in planarians. The evaluation of feeding and locomotion in response to chemical stress was evidenced to be sensitive at short exposure periods, showcasing the potentialities of planarian behavioural endpoints for ecotoxicity testing. With longer exposure periods, fecundity was shown to be a sensitive endpoint, while increased behavioural anomalies in unexposed newborns re-sulting from B[a]P-exposed parents, evidenced the importance of newborn condition as a reproduction-related endpoint in planarians and for transgenera-tional studies. The evaluation of internal concentrations of PAH-type com-pounds in the head and tail portions of exposed planarians revealed that these compounds accumulated more in the heads of planarians, providing a hint on the potential neurotoxicity of these compounds, as suggested by the observed behavioural effects. Moreover, the accumulation of PAH-type compounds in G. tigrina exposed to B[a]P-contaminated sediments or to contaminated prey, evidenced their potential for ecotoxicological experiments with contaminated sediments and to evaluate trophic transfer of contaminants. The results ob-tained in the present work indicate that planarians are sensitive to chemical stress, with a multitude of available endpoints, while showing potential for in-clusion as invertebrate predators in multispecies studies as invertebrate preda-tors. Therefore, their usage for ecotoxicological research is strongly recom-mended.As planárias de água doce são animais que possuem uma variedade de carac-terísticas que as tornou fundamentais para várias áreas do conhecimento, tais como a investigação em células estaminais, a neurofarmacologia ou a investi-gação sobre envelhecimento. O interesse por estes animais deve-se a atributos únicos como a existência de células estaminais distribuídas pelos seus corpos, a presença de um cérebro simples, mas com semelhanças ao sistema nervoso dos vertebrados, ou a sua aparente ausência de envelhecimento. O interesse pelas planárias como animais experimentais difundiu-se à área da investigação ecotoxicológica, não só devido à sua fácil manutenção em contexto laboratorial e sensibilidade a contaminantes ambientais, mas também à vasta gama de respostas que podem ser usadas para avaliar a teratogénese, a carcinogénese, a toxicidade comportamental e reprodutiva ou a neurotoxicidade. Para além disto, as planárias podem ser usadas em testes com múltiplas espécies como invertebrados epibentónicos predadores. Neste contexto, o presente trabalho pretendeu explorar os parâmetros ecotoxicológicos das planárias de água doce em resposta a contaminantes ambientais, através da utilização de hidrocarbo-netos aromáticos policíclicos (PAHs) como compostos modelo. Os PAHs são contaminantes ubíquos no ambiente, devido à variedade de fontes emissoras, tanto naturais, como antropogénicas, e à sua capacidade de serem transporta-dos através do ar por longas distâncias. Contudo, a avaliação de risco ambien-tal dos PAHs tem-se mostrado difícil, devido à variabilidade das capacidades de metabolização destes compostos nos invertebrados e à grande variedade de efeitos que os PAHs podem provocar nos organismos. Para alguns grupos de invertebrados, como é o caso das planárias, os efeitos destes compostos são (quase) desconhecidos. No sentido de explorar a potencial utilização das planá-rias de água doce no contexto da ecotoxicologia, este trabalho utilizou a espé-cie Girardia tigrina como organismo modelo e três PAHs com diferentes núme-ros de anéis aromáticos, o fenantreno, o pireno e o benzo[a]pireno (B[a]P), de 3, 4 e 5 anéis aromáticos, respetivamente. Foram delineados vários objetivos específicos: o desenvolvimento de ensaios para a avaliação dos parâmetros ecotoxicológicos nas planárias de água doce, a avaliação da toxicidade dos PAHs e a potencial acumulação dos PAHs em diferentes cenários de exposi-ção. Ao longo de 6 capítulos experimentais, os protocolos para a avaliação dos parâmetros ecotoxicológicos foram refinados e, mais especificamente, foi de-senvolvido um protocolo para avaliar a inibição alimentar de acordo com as características específicas da planária G. tigrina. Também se verificou que esta espécie de planária é sensível aos PAHs, tendo sido observada mortalidade, desintegração de tecidos, atrasos na regeneração, alterações comportamen-tais, alterações bioquímicas, diminuição da taxa reprodutiva e efeitos em planá-rias recém-nascidas. A severidade dos efeitos observados aumentou de acordo com as concentrações internas de PAHs nos tecidos das planárias. No entanto, apesar das semelhanças químicas entre os compostos, cada um dos PAHs provocou diferentes efeitos nas planárias. A avaliação da taxa de alimentação e locomoção mostrou ser sensível em resposta aos contaminantes em exposi-ções de curta duração, e evidenciou o potencial destes parâmetros para a ava-liação ecotoxicológica. Em períodos de exposição mais longos, a fecundidade mostrou ser um parâmetro sensível. Para além disso, através da observação dos recém-nascidos resultantes de progenitores expostos ao B[a]P, foi verifica-do que estes apresentavam anomalias comportamentais, evidenciando, assim, a importância da avaliação da condição dos recém-nascidos como um parâme-tro reprodutivo e em exposições multigeracionais. Constatou-se ainda que, nos tecidos das planárias, os PAHs se acumularam em maior quantidade na zona cefálica, potencialmente indicando que estes compostos poderão ser neurotóxi-cos para as planárias, como sugerem também as alterações comportamentais. Para além disto, a bioacumulação de PAHs em planárias expostas a sedimen-tos contaminados ou que consumiram presas contaminadas com B[a]P, de-monstrou o potencial destes animais para testes de avaliação ecotoxicológica de sedimentos e na avaliação da transferência trófica de contaminantes. Os resultados obtidos no presente trabalho indicam que as planárias são sensíveis a contaminantes, permitem a avaliação de uma grande variedade de parâme-tros e podem também ser usadas como predadores em testes com múltiplas espécies. Assim, a utilização das planárias de água doce para a investigação ecotoxicológica é fortemente recomendada.Programa Doutoral em Biologia e Ecologia das Alterações Globai

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data