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Hydrobiologia ◽  
2021 ◽  
Author(s):  
Mariusz Pełechaty ◽  
Bazargul Zhapparova ◽  
Michał Brzozowski ◽  
Andrzej Pukacz

AbstractThis study aimed to determine the relationships between the abundance of Nitellopsis obtusa, a controversial charophyte, locally red-listed in its native Eurasian range but invasive in North America, and the species diversity of macrophyte stands dominated by N. obtusa. Three lakes of different morphology, productivity and catchment were surveyed in the species native range. In each lake, the species composition and cover of three N. obtusa-dominated stands were determined monthly from spring to autumn and illustrated by the Shannon–Wiener diversity index. Water chemistry supplemented vegetation study. The species diversity turned out to be lake-specific and declined with the increasing share of N. obtusa, which developed mass occurrence in less mineralised and less fertile waters, leaving no space and limiting light and nutrient availability for large and branchy macrophytes. We postulate that this mechanism makes N. obtusa a superior competitor in less fertile waters and seems common to both native and invaded territories, as is the pool of macrophyte species most frequently co-occurring with N. obtusa.


Author(s):  
Svein Dale

AbstractIn boreal forests, food supplies typically have cyclic variations, and many species here fluctuate in numbers from year to year. One group of species showing large variations in population size is birds specialized on seeds from masting trees. Here, I analyze spatial patterns of a mass occurrence and habitat selection of the Common Redpoll (Carduelis flammea) during the breeding season in southeastern Norway in 2020 after a year with large seed crops from Norway Spruce (Picea abies) and Downy Birch (Betula pubescens). I found that Common Redpoll numbers increased with elevation and towards the northwest. Numbers were also strongly and positively correlated with snow depth in early April when snow was present mainly above 400 m elevation. Sites with snow cover in early April (30% of all sites) held 96.4% of all individuals recorded. Field observations indicated that Common Redpolls foraged extensively for spruce seeds on the snow until the end of May when young were independent. I suggest that the mass occurrence was due to a unique combination of exceptionally large seed crops of two tree species coinciding in the same year. The masting produced large amounts of food both for overwintering (birch seeds) and for breeding (spruce seeds), and during the breeding season snow cover facilitated access to food resources. Dependency of Common Redpolls on snow cover suggests that climate change may negatively impact some seed-eaters in boreal regions. On the other hand, higher temperatures may induce more frequent masting which may be beneficial for seed-eaters. Thus, climate change is likely to lead to complex ecosystem changes in areas where snow cover may disappear.


2021 ◽  
Vol 140 (1) ◽  
Author(s):  
Elena A. Jagt-Yazykova ◽  
Martin Košťák ◽  
John W. M. Jagt

AbstractA newly collected specimen of the enigmatic coleoid genus Longibelus is recorded from lower Turonian strata along the River Shadrinka in Sakhalin (Russian Far East). To date, this is the first record of Late Cretaceous coleoid cephalopods from the island and, in fact, from the entire Pacific coast of the Russian Federation. Lithological characteristics, coupled with published geochemical analyses (δ13C and Corg content), suggest the habitat of this coleoid taxon to have been the middle to outer (i.e. distal) shelf. Its provenance from the stratigraphical level that is known as the Scaphites Event, characterised by a mass occurrence of Scaphites and Yesoites, may be indicative of occasional or marginal overlap in ranges, rather than life in similar habitats. On the basis of lithological features and in view of the extremely rare occurrence of Longibelus in rich ammonite assemblages with clear ecological/bathymetric preferences, the natural habitat of Longibelus may have comprised neritic to mesopelagic zones over distal shelves and slopes.


PalZ ◽  
2021 ◽  
Author(s):  
Mario Schädel ◽  
Marie K. Hörnig ◽  
Matúš Hyžný ◽  
Joachim T. Haug

AbstractWithin Isopoda (woodlice and relatives), there are lineages characterised by a parasitic lifestyle that all belong to Cymothoida and likely form a monophyletic group. Representatives of Epicaridea (ingroup of Cymothoida) are parasitic on crustaceans and usually go through three distinct larval stages. The fossil record of Epicaridea is sparse and thus little is known about the palaeoecology and the origin of the complex life cycle of modern epicarideans. We present an assemblage of over 100 epicarideans preserved in a single piece of Late Cretaceous Myanmar amber. All individuals are morphologically similar to cryptoniscium stage larvae. The cryptoniscium stage usually constitutes the third and last larval stage. In modern representatives of Epicaridea, the cryptoniscium larvae are planktic and search for suitable host animals or adult females. These fossil specimens, though similar to some extant species, differ from other fossil epicaridean larvae in many aspects. Thus, a new species (and a new genus), Cryptolacruma nidis, is erected. Several factors can favour the preservation of multiple conspecific animals in a single piece of amber. However, the enormous density of epicarideans in the herein presented amber piece can only be explained by circumstances that result in high local densities of individuals, close to the resin-producing tree.


2021 ◽  
Vol 44 ◽  
pp. 91-97
Author(s):  
Maria V. Gavrilo ◽  
Igor I. Chupin ◽  
Mikhail V. Kozlov

Vize Island, located in the northern part of the Kara Sea (79°30’N, 76°59’E), is one of the least studied islands of the Russian High Arctic in terms of its biota. Hundreds of live and freshly dead individuals of Larch Budmoth Zeiraphera griseana (Hübner, 1799) were observed on this island from 16 July–2 August 2020. This is the first and the only terrestrial invertebrate ever discovered on Vize Island. The moths were likely transported to the island by air currents from the northern part of the Krasnoyarsk region, where an outbreak of Z. griseana was reported on over 75,000 ha. The distance travelled by moths approached 1200 km. Thus, the high Arctic islands are less isolated from insect migrants than was commonly thought. These islands will be colonised by boreal insects as soon as changing environmental conditions allow the establishment of local populations.


2021 ◽  
Vol 10 (4) ◽  
pp. 788
Author(s):  
Monika Sitarz ◽  
Alicja Buczek ◽  
Weronika Buczek

Due to their mass occurrence in some environments and high aggressiveness, blackflies (Simulium spp.) represent the most bothersome arthropods attacking humans. In this study, we describe the medical effects of blackfly infestations in humans in southeastern Poland. Local and systemic reactions to blackfly bites were monitored in 418 patients (61.24% of females and 38.76% of males) of medical centers. Only skin lesions at the site of the bites were found in 88.52% of the patients, whereas accompanying systemic reactions were diagnosed in 11.48%. The most common signs observed in the area of the bites were pruritus (94.74%), burning (55.02%), edema (44.02%), and erythema (40.91%). The skin lesions, which were most often grouped small papules and papular and purpuric lesions with a varied range, typically persisted for several days, or for several weeks in some patients. Statistical analyses confirmed that the persistence of the skin lesions did not depend on the sex of the patients and the number of blackfly infestations. The systemic reactions to the components of the blackfly saliva were manifested by headache, increased body temperature, arthralgia, lymphadenopathy, and menstrual disorders in the females. The patients were most often attacked simultaneously by many blackflies on exposed parts of the body, mainly the upper limb, lower limb, head, and neck areas. The investigations indicate that blackflies are an important etiological factor of dermatitis and other symptoms in humans; hence, they should be considered in clinical diagnosis.


Author(s):  
Živana Krejić ◽  
Jelena Palić

The paper is an overview on Yugoslav seaside tourism propaganda and mass tourism of the working class. The analysis is based on the archival material analyzed so far in the field of the history of tourism development and published scientific papers related to travel culture in Yugoslavia. The research aims to look at and analyze the tourist propaganda in Yugoslavia during the 20th century from a sociological aspect, when one of the main characteristics of tourism was its mass occurrence. Despite the development of the economy and the rise of tourism, the citizens of Yugoslavia had a short vacation, during which they went to the sea, spas, mountains, most often making their own travel plans, and used the services of travel agencies the least. Numerous catalogs, brochures, newspaper advertisements represent important segments of tourist propaganda and a signpost for domestic tourists to popular destinations. The difficult position of workers who struggled to preserve the idea of going on vacation was also visible through some of the slogans about summer vacations: "Those who have money bathe in the sea, and those who do not have money bathe at home in the washbowl." The standard of living of the people dictated their decisions about travel, and only in 1964 was the decision made that the annual vacation should last for six days and be paid, which gave tourism the epithet of social tourism. The results of the overview provide insight into the everyday life of the inhabitants of Yugoslavia, their possibilities for going on vacation, tourist propaganda which was very lavish in its beginnings, but also the most common destinations they travelled to.


2021 ◽  
Vol 731 ◽  
pp. 135-158
Author(s):  
Jindřich Roháček ◽  
Andrea Tóthová

A new species of Anthomyzidae (Diptera), viz., Mumetopia interfeles Roháček sp. nov. (both sexes), is described from Chile, based on a large series collected from a small grassy area (consisting of a non-native species, Hordeum murinum L.) among houses in the city of Valparaíso. Its systematic affiliation, phylogenetic relationships, and biology are discussed. Cases of mass occurrence of adult Anthomyzidae, particularly those in anthropogenic habitats, are reviewed and general features of them discussed. A phylogenetic hypothesis is proposed for the relationships of the new species and the Chamaebosca group of genera within Anthomyzidae (64 species in dataset), based on Bayesian inference and maximum likelihood analyses of seven DNA markers (12S, 16S, 28S, COI, COII, CytB, ITS2). Taxonomic limits of the genus Mumetopia Melander, 1913 are discussed. Based on a new molecular hypothesis and a previous cladistic analysis of morphological data (Roháček & Barber 2009), a broadened, better-supported concept of Mumetopia (s. str.) is proposed to include M. interfeles sp. nov. (and its unnamed relatives) and externally aberrant, undescribed species endemic to the Juan Fernández Islands. Apart from Anthomyzidae (M. interfeles sp. nov. only), the community of Diptera associated with H. murinum was dominated by phytophagous Chloropidae: Ceratobarys sacculicornis (Enderlein, 1911) occurred in extremely high numbers similar to those of M. interfeles sp. nov., while the less abundant Opetiophora sp. represents the first record of the genus from South America.


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