83 research outputs found
Effects of Ponderosa Pine Ecological Restoration on Forest Soils and Understory Vegetation in Northern Arizona
The human exclusion of wildfire and overgrazing by livestock since settlement have caused dramatic changes in ponderosa pine (Pinus ponderosa Dougl ex Laws) forest ecosystems. These changes include increased numbers of tree stems, reduced understory cover and diversity, and the introduction of invasive, non-native understory species. This study evaluated the coverage and species composition of understory vegetation present in the “cool-season” (late spring and early summer) in a ponderosa pine forest on grazed and ungrazed plots that had undergone restoration treatments on three different soil/geologic parent material types near Flagstaff, Arizona, twelve years after tree thinning and grazing exclosure treatments were applied. Several measured soil properties, such as soil respiration and temperature, were also evaluated in this study. Species richness of “cool-season” vegetation was influenced more by grazing practices than restoration treatments. Differences could be less or greater when vegetation that is active later in the season is measured. Vegetative cover was significantly influenced by restoration treatments (9.3% cover under open canopies and 6.5% under dense canopies), probably due to differences in competition for light and other resources (i.e. soil moisture and nutrients). Unlike finding by Abella et al. (2015), who studied “warm-season” vegetation, “cool-season” understory cover was not influenced by soil parent material type in this study, which might suggest that differences in understory cover due to soil properties are only seen shortly after restoration treatments are applied, or the time of year vegetation is evaluated may play a role in the differences seen. Soil respiration was highest on limestone soil parent material type (3.3 g C-CO2 m-2 day-1), and soil temperature was lowest under closed canopy treatments (15°C)
Highly feminised sex ratio estimations for the world’s third largest nesting aggregation of loggerhead sea turtles
Despite being a fundamental life-history character, there is a paucity of populationwide, data-driven studies of primary sex ratios for any marine turtle species. The Republic of Cape Verde hosts the third-largest nesting population of loggerhead turtles Caretta caretta in the world (hosting up to 15% of global nesting by the species). Weighting for the spatial distribution of nests, we estimate that 84% of female hatchlings are currently likely produced across the population, with 85% of nests laid on Boa Vista, where incubation temperatures are coolest. In future climate change scenarios (by 2100), irrespective of beach, island or sand colour, sex ratios reach over 99% female, and 3 islands (Fogo, Sao Nicolau, Santiago) would cease to produce males, with >90% of nests incubating at lethally high temperatures. Given that most of the population cannot move to nest on cooler islands, we highlight that temporal refugia are amongst the primary means available to this population to adapt. Under a low-emissions scenario, without phenological adaptation, there would only be an estimated 0.14% males produced across the whole population, while under mid- and high-emissions scenarios, male production may cease on most islands.</p
Highly feminised sex ratio estimations for the world’s third largest nesting aggregation of loggerhead sea turtles
Despite being a fundamental life-history character, there is a paucity of populationwide, data-driven studies of primary sex ratios for any marine turtle species. The Republic of Cape Verde hosts the third-largest nesting population of loggerhead turtles Caretta caretta in the world (hosting up to 15% of global nesting by the species). Weighting for the spatial distribution of nests, we estimate that 84% of female hatchlings are currently likely produced across the population, with 85% of nests laid on Boa Vista, where incubation temperatures are coolest. In future climate change scenarios (by 2100), irrespective of beach, island or sand colour, sex ratios reach over 99% female, and 3 islands (Fogo, Sao Nicolau, Santiago) would cease to produce males, with >90% of nests incubating at lethally high temperatures. Given that most of the population cannot move to nest on cooler islands, we highlight that temporal refugia are amongst the primary means available to this population to adapt. Under a low-emissions scenario, without phenological adaptation, there would only be an estimated 0.14% males produced across the whole population, while under mid- and high-emissions scenarios, male production may cease on most islands.</p
Patterns and intensity of ghost crab predation on the nests of an important endangered loggerhead turtle population
© 2015 Elsevier B.V. Predation is one of the most important threats to the early life stages of most endangered vertebrates. On small oceanic islands that host very important endangered sea turtle rookeries, ghost crabs are the main nest predators. Mortality in nests was evaluated on the island of Boa Vista which hosts around 75% of the nests in the Cape Verde archipelago, which is one of the world's largest loggerhead turtle (. Caretta caretta) rookeries. In an extensive survey of the island, egg mortality significantly varied between beaches and averaged 70%. One of the main causes of egg mortality was predation by ghost crabs (. Ocypode cursor) that stole an average of 33 eggs per nest. No other egg predator was observed during the study. In an intensive field experiment, the egg mortality for non-protected nests was 82% and ghost crabs predated an average of 50% of the total number of eggs. Even though female tracks on the beach are very conspicuous immediately after egg laying, very few nests were predated during this period. In contrast, most of the nests were predated at the end of the incubation period (after day 40 of incubation), when female tracks are not visible on the beach. Nests predated by larger crabs suffered a lower predation rate, suggesting that these larger dominant crabs defend the nest they prey upon. On-beach nest relocation had no significant influence on reducing egg predation. Females preferred nesting on beaches with higher hatching success although predation was not a risk that they seemed able to assess.Peer Reviewe
Risk assessment of wildlife-watching tourism in an important endangered loggerhead turtle rookery
T: Wildlife-watching tourism is a non-exploitative activity that can contribute to sustainable economic development of coastal communities. However, it is important to assess the potential
impact and implement best practices to mitigate any negative effects of such tourism. We studied
this issue on Boa Vista (Cabo Verde), which supports around 60% of nesting activity of one of the
most endangered loggerhead turtle rookeries globally. Between 2013 and 2016, authorized turtle
watching involved 4942 tourists, generating a mean annual direct income of >USD 289 000 and the
direct creation of >250 jobs. On JoĂŁo Barrosa beach, which supports around 20% of nests and 48%
of turtle-watching activity on the island, we tested the influence of turtle watching on nesting behavior, reproduction and nest-site fidelity. Nesting females observed by tourists spent significantly
less time on nest-camouflaging behavior, although all other phases of nesting were unaffected.
There were no statistically significant differences between the re-nesting frequency of females
watched (n = 187) and non-watched (n = 972) by tourists. We found no evidence that the current turtle-watching intensity has an effect on turtle reproduction. Turtle poaching remains a severe threat
on beaches with no turtle watching, although it has strongly decreased on beaches with tourist
visits. We suggest tour guides follow best practice guidelines to minimize disturbance, specifically
retreating from the immediate vicinity of a female during nest camouflaging to mitigate the observed impact.Peer reviewe
Access to information and degree of community awareness of preventive health measures in the face of covid-19 in Spain
[EN] The COVID-19 pandemic is posing a major health crisis. Spanish legislation establishes the mandatory use of masks and the implementation of hygienic measures such as hand washing and physical distancing. The aim of this study is to describe access to information and the level of community knowledge/adoption about the preventive measures proposed by the Spanish health authorities in response to the COVID-19 pandemic and to analyze the influence of socio-demographic factors in compliance among people over 18 years of age resident in Spain. An observational, descriptive and transversal study was conducted. Data was collected on sociodemographic variables, access to information and the degree of knowledge/adoption about the preventive measures: use of masks, hand hygiene and physical distancing. A total of 1811 people participated. The average age was 45.1 ± 15.1 years, predominantly female (69.3%), from an urban geographical area (74%), with a higher education level of 53.2%. Most of the respondents (57.5%) are or live with people at risk. The main access to information on preventive measures was from secondary sources (49.2%), with television being the main medium; 72.3% think that there are some difficulties in accessing information, while 8.7% of the participants do not consider the use of masks to be useful. As regards the choice of type of mask, the majority of people (44.8%) opt for the surgical variety; 88.5% of respondents believe that the physical distancing established is at least 1.5 m. This study confirmed that socio-demographic factors influence compliance with or the degree of knowledge/adoption of the preventive measures proposed to combat the COVID-19 pandemic and has made it possible to ascertain the sectors of the population with the greatest deficiencies in this respect. It shows the importance of implementing health information and education systems in the community, and it is advisable to promote specific programs aimed at men, people living in rural areas and people with a low level of education.S
Accacoelium contortum (Trematoda : Accacoeliidae) a trematode living as a monogenean: morphological and pathological implications
Accacoelium contortum (Rudolphi, 1819) Monticelli, 1893 is a frequent but poorly known trematode found on gills, pharynx and digestive tract of the ocean sunfish Mola mola (L.). Although the morphology of A. contortum agrees with that of a typical endoparasitic trematode, with two relatively small suckers and no large holdfasts, this parasite is normally ectoparasitic. The main objective of this paper is to explore this peculiar host-parasite relationship. A total of 106 ocean sunfish were examined for the presence of A. contortum. The oropharyngeal chamber (gills and pharynx) and the digestive tract were analysed. As the previous descriptions of this species seem to be based on contracted specimens, for the morphological study the parasites were killed using two methods: with hot 70 % ethanol (with relaxed bodies) and with 70 % ethanol at room temperature (with contracted bodies). For histological studies, samples from fresh fish with parasitised left gills, pharynx and digestive tract were fixed in buffered 10 % formalin. For molecular studies the 18S, 28S and ITS-2 sequences were provided and compared with the available data in GenBank®. New information on the morphology of A. contortum and on the parasite-related response and pathological alterations in the host are given. New diagnostic traits for some structures are provided: e.g. tegumental papillae of the forebody with apical digitiform swellings and mouth surrounded by a circum-oral crown of simple papillae. The length of the ventral sucker peduncle and the position of the vitellarium were found to be associated with the contraction degree of the specimen. Immature individuals of this species are described for the first time. An intense proliferative inflammatory response of host gill and pharynx epithelium at the host-parasite interface was detected and parasites became partially covered by overgrowths of host tissues. The induction of prominent histological alterations associated with A. contortum seems to be an adaptation to the external environment, an unusual location for trematodes
Patterns and intensity of ghost crab predation on the nests of an important endangered loggerhead turtle population
a b s t r a c t a r t i c l e i n f o Predation is one of the most important threats to the early life stages of most endangered vertebrates. On small oceanic islands that host very important endangered sea turtle rookeries, ghost crabs are the main nest predators. Mortality in nests was evaluated on the island of Boa Vista which hosts around 75% of the nests in the Cape Verde archipelago, which is one of the world's largest loggerhead turtle (Caretta caretta) rookeries. In an extensive survey of the island, egg mortality significantly varied between beaches and averaged 70%. One of the main causes of egg mortality was predation by ghost crabs (Ocypode cursor) that stole an average of 33 eggs per nest. No other egg predator was observed during the study. In an intensive field experiment, the egg mortality for non-protected nests was 82% and ghost crabs predated an average of 50% of the total number of eggs. Even though female tracks on the beach are very conspicuous immediately after egg laying, very few nests were predated during this period. In contrast, most of the nests were predated at the end of the incubation period (after day 40 of incubation), when female tracks are not visible on the beach. Nests predated by larger crabs suffered a lower predation rate, suggesting that these larger dominant crabs defend the nest they prey upon. On-beach nest relocation had no significant influence on reducing egg predation. Females preferred nesting on beaches with higher hatching success although predation was not a risk that they seemed able to assess
Margarines and fast-food french fries: low content of trans fatty acids
The lipid fraction of margarines and fast food French fries, two types of foods traditionally high in trans fatty acids (TFA), is assessed. TFA data reported worldwide during the last 20 years have been gathered and show that some countries still report high TFA amounts in these products. The content of TFA was analysed in margarines (two store and four premium brands) and French-fries from fast-food restaurants (five chains). All samples were collected in Pamplona (Navarra, Spain). The margarines showed mean values of 0.68% and 0.43% (g TFA/100 g fat) for the store and premium brands, respectively. The French fries' values ranged from 0.49% to 0.89%. All samples were lower than the 2% set by some European countries as the maximum legal content of TFA in fats, and contained less than 0.5 g/serving, so they could also be considered "trans free products". This work confirmed that the presence of TFA is not significant in the two analysed products and contributes updated food composition tables, key tools for epidemiological and nutrition studies
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