29 research outputs found
Changing Microarthropod Communities in Front of a Receding Glacier in the High Arctic
This study was carried out at Ny-Ålesund on Spitsbergen in Svalbard (High Arctic).
Eight study sites were established along a transect from the fjord to the snout of the glacier. The sites
di ered from each other by the type of vegetation cover and soil characteristics. Soil samples were
collected and placed in Tullgren funnels. Extracted arthropods were represented by two groups
of mites (Mesostigmata and Oribatida) and springtails (Collembola). The pioneer species that
occurred first after retreat of the glacier were representatives of the Collembola (Agrenia bidenticulata
and Hypogastrura concolor). Later, other springtails appeared including Folsomia alpha, Folsomia
quadrioculata, Hypogastrura concolor, Isotoma anglicana, Sminthurinus concolor and the first species of
oribatid mites; Camisia foveolata and Tectocepheus velatus velatus. Arthropod communities recorded
along the transect were characterized by large variations in both species composition and abundance
of individuals. The greater the distance from the glacier snout, the greater the species richness (2 to
22 species). The mean number of species per sample was the lowest at site 8 (1 0.71) (the closest
to the glacier) and greatest at site 1 (14 1.41) (furthest from the glacier). The Simpson’s diversity
index (D) was distinctly greater at sites 1 (4.61 0.06) and 3 (3.94 0.11) than at other sites, especially
site 8 (1.07 0.06). Densities were least in the samples closest to the glacier (30 to 101 individuals;
density 3000–10,100 individuals/m2). At the other locations, abundance was highly variable (905 to
7432 individuals; density 90,500–743,200 individuals/m2). The mean abundances were greatest at
sites 2 and 3. The great variations in total abundances observed were often due to the presence or
absence of one or more dominant species exhibiting extreme abundance variability between sites.
The microarthropod community of the High Arctic is composed of heterogeneous circumpolar species,
yet on a landscape scale is extremely dependent on local environmental conditions which may be
subject to rapid change
Origin, genetic structure and evolutionary potential of the natural hybrid Ranunculus circinatus × R. fluitans
Mite communities (Acari: Mesostigmata, Oribatida) in the red belt conk, Fomitopsis pinicola (Polyporales), in Polish forests
The fruiting bodies of bracket fungi are a specific microhabitat colonized by various
invertebrates of which mites (Acari) are rarely studied, and if they are, the study is usually
faunistic. The aim of the research was to determine whether the diversification of mite
assemblages (Mesostigmata, Oribatida) inhabiting the fruiting bodies of Fomitopsis pinicola
(Sw.) P. Karst. (Polyporales) are connected with the character of the forests and/or the
degree of decay (DD) of the fruiting bodies. The research was conducted at Białowieża
National Park (BNP), in forests close to natural ones and in Karkonosze National Park
(KNP) which was affected by a large-scale forest dieback in the 1980s. Eighty fruiting bodies
(40 at each study site) of F. pinicola belonging to four DD categories were collected.
In total, 4,345 individuals of 120 mite species were recorded at BNP, and 13,912 individuals
of 96 species were recorded at KNP. Analyses revealed that the sample dispersion at
each study site was comparable, nevertheless the samples from each study site were clearly
grouped into slightly overlapping sets which allow observation of the differences between
them. In the less decayed fungi (DD 1 and 2) there were fewer mite species and individual
mites than in the more decayed samples (DD 3 and 4). There were also significant
differences between the fauna of the fungi in each particular DD: the fauna of DD 1 differed
from all others, whereas the fauna of heavily decayed fungi (DD 3 and 4) was more
comparable
Oribatid communities and heavy metal bioaccumulation in selected species associated with lichens in a heavily contaminated habitat
The study examines oribatid communities and heavy metal bioaccumulation in selected species associated with different microhabitats of a post-smelting dump, i.e. three lichen species of Cladonia with various growth forms and the slag substrate. The abundance of oribatids collected from the substrate was significantly lower than observed in lichen thalli. The morphology and chemical properties of lichens, and to some extent varying concentrations of heavy metals in thalli, are probably responsible for significant differences in oribatid communities inhabiting different Cladonia species. Some oribatids demonstrate the ability to accumulate zinc and cadmium with unusual efficiency, whereas lead is the most effectively regulated element by all species. A positive correlation was found between Zn content in all studied oribatids and their microhabitats. Oribatids exploring different food resources, i.e. fungivorous and non-fungivorous grazers, show considerable differences in bioconcentrations of certain elements
The role of bracket fungi in creating alpha diversity of invertebrates in the Białowieża National Park, Poland
Bracket fungi are seen mainly as the cause of economic losses in forestry, and their role as creators of biodiversity is relatively poorly understood. The aim of the study was defining the manner in which the degree of decay (DD) of the fruiting bodies determines the character of the invertebrate assemblages colonising them. The effect of this group of fungi on the modification of biodiversity of invertebrates (Aranae, Opiliones, Pseudoscorpionida, two groups of mites- Mesostigmata and Oribatida, and Collembola and Insecta) was investigated by analyzing 100 fruiting bodies of 10
species of bracket fungi divided into four DD classes. The material was collected at Białowieża National Park, which is considered to be the largest area of natural forests in the North European Plain. 16 068 invertebrate individuals classified into 224 species were obtained. Oribatid mites (12 543 individuals) constituted the largest group of individuals, which were classified into 115 species with the most numerous Carabodes femoralis (8,811 individuals). Representatives of this group of mites have been reported previously in the publications on bracket fungi; however, the contributions of Oribatida and other groups of invertebrates were not broadly compared. Moreover, the species such as Hoploseius mariae and H. oblongus, which were predominantly found in fruiting bodies of bracket fungi, have also been discerned. The invertebrate fauna differs depending on DD of the samples: In the more decayed samples, a higher number of both individuals and species were recorded compared to the samples with lower DDs; however, this trend proved to be nonlinear. The DCA and cluster analysis revealed a similarity of the invertebrate assemblages from the 2 DD and 4 DD samples. They also indicated that the group 3 DD differed the most from all the other samples. The indicator species analysis identified species characteristic to individual DDs: For group 1 DD, it was, for example, Hoploseius oblongus; for 2 DD - Orchesella bifasciata; and for 3 DD-Chernes cimicoides, while for 4 DD-Dinychus perforatus
Mites (Acari, Mesostigmata) in boreal Scots pine forest floors: effect of distance to stumps
Biodiversity and structure of spider communities along a metal pollution gradient
The objective of the study was to determine whether long-term metal pollution affects communities of epigeal spiders (Aranea), studied at three taxonomic levels: species, genera, and families. Biodiversity was defined by three indices: the Hierarchical Richness Index (HRI), Margalef index (DM) and Pielou evenness index (J). In different ways the indices describe taxa richness and the distribution of individuals among taxa. The dominance pattern of the communities was described with four measures: number of dominant species at a site, percentage of dominant species at a site, average dominant species abundance at a site, and the share of the most numerous species (Alopecosa cuneata) at a site. Spiders were collected along a metal pollution gradient in southern Poland, extending ca. 33 km from zinc and lead smelter to an uncontaminated area. The zinc concentration in soil was used as the pollution index.The study revealed a significant effect of metal pollution on spider biodiversity as described by HRI for species (p = 0.039), genera (p = 0.0041) and families (p = 0.0147), and by DM for genera (p = 0.0259) and families (p = 0.0028). HRI correlated negatively with pollution level, while DM correlated positively. This means that although broadly described HRI diversity decreased with increasing pollution level, species richness increased with increasing contamination. Mesophilic meadows were generally richer. Pielou (J) did not show any significant correlations. There were a few evidences for the intermediate disturbance hypothesis: certain indices reached their highest values at moderate pollution levels rather than at the cleanest or most polluted sites
Changing microarthropod communities in front of a receding glacier in the High Arctic
This study was carried out at Ny-Ålesund on Spitsbergen in Svalbard (High Arctic). Eight study sites were established along a transect from the fjord to the snout of the glacier. The sites differed from each other by the type of vegetation cover and soil characteristics. Soil samples were collected and placed in Tullgren funnels. Extracted arthropods were represented by two groups of mites (Mesostigmata and Oribatida) and springtails (Collembola). The pioneer species that occurred first after retreat of the glacier were representatives of the Collembola (Agrenia bidenticulata and Hypogastrura concolor). Later, other springtails appeared including Folsomia alpha, Folsomia quadrioculata, Hypogastrura concolor, Isotoma anglicana, Sminthurinus concolor and the first species of oribatid mites; Camisia foveolata and Tectocepheus velatus velatus. Arthropod communities recorded along the transect were characterized by large variations in both species composition and abundance of individuals. The greater the distance from the glacier snout, the greater the species richness (2 to 22 species). The mean number of species per sample was the lowest at site 8 (1 ± 0.71) (the closest to the glacier) and greatest at site 1 (14 ± 1.41) (furthest from the glacier). The Simpson’s diversity index (D) was distinctly greater at sites 1 (4.61 ± 0.06) and 3 (3.94 ± 0.11) than at other sites, especially site 8 (1.07 ± 0.06). Densities were least in the samples closest to the glacier (30 to 101 individuals; density 3000-10,100 individuals/m2). At the other locations, abundance was highly variable (905 to 7432 individuals; density 90,500-743,200 individuals/m2). The mean abundances were greatest at sites 2 and 3. The great variations in total abundances observed were often due to the presence or absence of one or more dominant species exhibiting extreme abundance variability between sites. The microarthropod community of the High Arctic is composed of heterogeneous circumpolar species, yet on a landscape scale is extremely dependent on local environmental conditions which may be subject to rapid change
Fractionation of chromium and lead in anaerobic co-digestion
Anaerobic digestion is a common method of waste treatment various kinds of organic waste. The most commonly used substrates for the co-fermentation process are sewage sludge and organic fraction of municipal waste. The solid residue that is produced by fermentation can be used as an organic fertilizer. Restrictions on the use of fermented organic waste may be the content of heavy metals. Fractionation of heavy metals, based on sequential extraction, allows the assessment of the degree of hazard to the environment at the time of application to the soil of digested sludge. Two anaerobic digestion process cycles were performed, using different sewage sludge and municipal waste organic fraction mixing ratios. In the first cycle - M70, the materials used in the bioreactor contained 70% municipal organic waste and 30% sewage sludge. The material used in the second cycle - M30 contained 30% municipal organic waste and 70% sewage sludge. The volume of each batch was 50 dm3. The sequential extraction procedure developed by Tessier et al. was used in sludge anaerobic digestion to determine the heavy metal (Cr and Pb) fractionation. The paper presents the results of studies on changes in Cr and Pb concentrations in various fractions during the process of fermentation of substrates. During the process the immobilization of the tested metals was followed, which confirms the low values of mobility factor (Mf). The aim of this work was also to present the dependence of the composition of the mixture of organic waste, which were subjected to methane fermentation, to the distribution of metals in individual fractions. A mixture of organic waste, consisting of 70% organic fraction and 30% sewage sludge, was characterized by lower Mf values for Cr than in a 70% sludge mixture. On the other hand, the higher Mf values for Pb were recorded in waste in which 70% was organic fraction. Both studied elements were mainly found in the form of compounds difficult to access for living organisms, as evidenced by low values of mobility factor.Fermentacja metanowa jest powszechną metodą przetwarzania różnego rodzaju odpadów organicznych, w tym osadów ściekowych. Najczęściej stosowanymi substratami do procesu kofermentacji są osady ściekowe i frakcja organiczna odpadów komunalnych. Ograniczeniem w stosowaniu przefermentowanych odpadów organicznych jako nawozu może być zawartość metali ciężkich, w tym związków chromu i ołowiu. W pracy przedstawiono wyniki badań, dotyczące zmian zawartości Cr i Pb w poszczególnych frakcjach, w trakcie trwania procesu fermentacji dwóch różniących się składem mieszanin odpadów. Frakcjonowanie Cr i Pb przeprowadzono, wykorzystując schemat modyfikowanej ekstrakcji sekwencyjnej opracowanej przez Tessiera i współpracowników. Zauważono, że Cr i Pb występowały głównie we frakcji organicznej i rezydualnej. W trakcie trwania procesu następowała immobilizacja badanych metali, co potwierdzają niskie wartości współczynnika mobilności (Mf). Celem pracy było przedstawienie wpływu składu mieszaniny odpadów o zmiennych proporcjach na proces fermentacji metanowej i dystrybucję metali w poszczególnych frakcjach. Mieszanina odpadów organicznych, składająca się z 70% frakcji organicznej odpadów i 30% osadu ściekowego, charakteryzowała się mniejszymi wartościami Mf dla Cr niż mieszanina zawierająca 70% osadu ściekowego. Natomiast wyższe wartości Mf dla Pb zanotowano w mieszaninie odpadów, w których 70% stanowiła frakcja organiczna. Oba badane pierwiastki występowały głównie w postaci związków trudno dostępnych dla organizmów żywych, o czym świadczą małe wartości współczynników mobilności
Evaluation of compost stability in real time
W pracy przedstawiono wyniki badań próbek kompostu pobieranych w kolejnych fazach jego produkcji metodą pryzm napowietrzanych poprzez okresowe przerzucanie. Surowiec do kompostowania stanowiły odwodnione mechanicznie, częściowo ustabilizowane osady ściekowe z oczyszczalni ścieków komunalnych w Słupsku. Prezentowane wyniki są związane z tematem badawczym dotyczącym opracowania modelu matematycznego do oceny stabilności biologicznej kompostu w trakcie jego produkcji. Podstawowym celem modelowania numerycznego będzie stworzenie praktycznego narzędzia, umożliwiającego ocenę stabilności kompostu w czasie rzeczywistym (on-line), w oparciu o wartość prognozowanego wskaźnika AT-4. Monitorowane w trakcie kompostowania wskaźniki fizykochemiczne, stanowiące zmienne niezależne, to temperatura i stężenie tlenu w porach kompostu oraz sucha masa, substancja organiczna, OWO i azot ogólny.The paper presents the results of analysis of compost samples collected in successive phases of compost production that relies on forming windows aerated by periodical shifting. Partially stabilized and mechanically dehydrated sludge from municipal sewage treatment plant in Slupsk was an essential raw material for composting. The presented results are related to the topic of research on the development of a mathematical model to assess the biological stability of compost during its production. The primary objective of the numerical modeling will be to create a practical tool for assessing the stability of compost in real time (on-line), based on the projected value of the indicator AT-4. Indicators treated as independent variables, monitored during the composting process, were temperature and oxygen concentration in the pores of compost, dry matter, organic matter, TOC and total nitrogen