Microhabitats and oribatid fauna : comparison of 2 sampling approaches

Oribatid fauna highly varies among habitats, but different microhabitats within a habitat are also characterized by different mite species. The main goal of the research was to compare the observed structure of an oribatid community when samples were collected at random from the soil-litter layer of 0-10 cm in depth (standard approach) and selectively from 6 types of available microhabitats (complex approach). Samples were taken within a small plot (10 m × 10 m) in a forested area of the Silesian Park (Chorzów, south Poland). Overall, 2642 specimens of Oribatida belonging to 62 species were collected in 66 samples. The structure of the oribatid community observed by means of the 2 sampling approaches was completely different. The abundance and species richness of oribatid mites collected from 6 microhabitats were significantly higher than in the soil-litter layer alone. Results of this study show that random collecting of only soil-litter samples may reduce the evaluation of species richness in a study area by 40%. Each of the studied microhabitats supported a peculiar oribatid fauna

Invasive giant knotweed (Fallopia sachalinensis) alters the composition of oribatid mite communities

Plant invasions are a serious global threat to biodiversity and ecosystem stability. The invasive giant knotweed Fallopia sachalinensis (synonym: Reynoutria sachalinensis) is one of the most aggressive plant invaders in many countries. It forms dense stands that prevent other species from growing. To assess the impact of the knotweed, oribatid mite communities were studied under Fallopia-free native vegetation and at Fallopia-infested sites (2 types: 90–100% and 30% of coverage) with similar soil. All the sites are located in mixed forest in the Kraków-Częstochowa Upland (Jura Krakowsko-Częstochowska) in south Poland. Species composition and functional group composition of oribatid mite communities were compared. In total, 1540 specimens belonging to 70 oribatid species were collected from 90 soil samples. This successful exotic invasive species had a moderate influence on species richness (20% less species at the totally invaded site than at the Fallopia-free site) and a profound effect on soil oribatid mite community composition. Several oribatid species characteristic of a particular site were observed. Shifts were detected in proportions of groups with different habitat specificity (e.g. higher proportion of eurytopic mites at invaded sites), ecomorphological groups (e.g. lower proportion of litter-dwelling mites at invaded sites), trophic groups (e.g. lower proportion of macrophytophagous mites at invaded sites) and zoogeographical groups (e.g. higher proportion of mites with broad geographical distribution at invaded sites). These observations prove the radical negative change of environmental conditions for soil oribatid mites as a result of Fallopia invasion. The increase in sexually reproducing oribatid mites at invaded sites suggests that this way of reproduction is preferable when resources are in shortage

Oribatid mite (Acari: Oribatida) communities reveal the negative impact of the red oak (Quercus rubra L.) on soil fauna in Polish commercial forests

The red oak (Quercus rubra L.) is a woody plant brought to Europe from North America for its decorative value and high tolerance to frost and pollution. The species has been planted for the reclamation of brownfield sites, and introduced to commercial forests to enrich local biodiversity. Although in Poland its presence was associated with depauperation of local flora, its invasive status is still under discussion. The aim of this study was to determine the impact of red oak stands on Acari communities (Oribatida, Mesostigmata, Astigmata, Prostigmata). In the detailed analyses we focused on the Oribatida species, one of the best bioindicators of soil condition. The presence of the red oak was compared to the pedunculate (native) oak, also planted on poor acid soils. The research design included oak stands introduced in commercial forests, divided into two groups: young and old. A total number of 240 soil samples were collected, and 173 species of oribatid mites were identified. A low proportion of the Oribatida species typical for the Palearctic region, specific to deciduous forests, with sexual reproduction and belonging to the trophic level of secondary decomposers, significantly distinguished the old alien oaks from old native oaks. The results presented in this work are one of the few which concern the reaction of soil oribatid mite community to plant invasions, and provide evidence of the harmful impact of these alien tree species, which can be overlooked in short-term studies

New species of Moritzoppia and Medioppia from the Beskidy Mountains, Poland (Acarina, Oribatida, Oppiidae)

Moritzoppia sharipovi sp. n. and Medioppia beskidyensis sp. n. are described from Poland. M. sharipovi is distinguished from other species by the rostrum, sensilli, the crista and the large size. M. beskidyensis differs from all other species by the tubercles in the posterior margin of the prodorsum, the form of the rostrum, the number of genital hairs and the fusiform sensilli. A new combination, Medioppia ordunensis (Iturrondobeitia & Salona, 1988) comb. n. is presented

Importance of tree hollows for biodiversity of mites (Acari) in the forest reserve „Śrubita” (Carpathian Mountains, south Poland)

Tree hollows harbour a specialized fauna, and mites usually are the most numerous arthropods in this microhabitat. Mite fauna in 3 types of tree hollows was studied in the forest reserve “Śrubita” near Żywiec, at an altitude of about 850 m. In total, 2037 individuals of Acari and 1414 of Oribatida, representing 72 species, were collected. Over 1200 individuals per 100 g dry weight of wood dust were collected from tree hollows. The total number of oribatid species in tree hollows was higher than in the forest floor. Most species (also dominants) were obligate members of communities of a certain type of tree hollows

Communities of mites (Acari) in litter and soil under the invasive red oak (Quercus rubra L.) and native pedunculate oak (Q. robur L.)

Because of thoughtless decisions or unintentional introduction, alien species disturb native ecosystems. R ed oak (Quercus rubra), among other alien woody plants, is still used to rehabilitate degraded land because of its better resistance to pollution and faster growth, as compared to native tree species. Soil mites, especially O ribatida, are good bioindicators of ecosystem disturbance, so the main goal of this study was to explore the influence of invasive and native oaks on mite communities. F orest stands dominated by 40-year-old Q. rubra or 35-year-old Q. robur were compared. O ver 2300 soil mites were extracted from 20 soil and 20 litter samples. M ite densities in the communities were higher in red oak litter, which is probably a result of the thicker layer of shed leaves. C hanges in species composition of oribatid communities were observed in litter, in contrast to a lack of differences in soil. These observations are consistent with other researches on invasive woody plants. W e expect that over time these changes will also be noticeable in the soil and will increase in litter

Scientists warn and call for the protection of our planet

We have never been in the history of mankind as a species in such a moment and place. We have never faced such a challenge during our stay on this planet. Such a great mobilization of scientists from around the world has never happened before. At the end of 2017, an appeal of scientists to humanity (World Scientists’ Warning to Humanity: A Second Notice) was published in the prestigious journal “Bioscience” [1]. The article was written by an international team led by William Ripple, distinguished professor in the College of Forestry at Oregon State University. The warning was signed by 15,364 representatives of the science from 184 countries

Colonization and development of oribatid mite communities (Acari: Oribatida) on post-industrial dumps

W pracy analizowano sukcesję zgrupowań glebowych roztoczy z rzędu Oribatida na sześciu zwałach poprzemysłowych różnego typu (zwały kopalniane, zwał hutnictwa żelaza, zwał pocynkowy, osadnik wód kopalnianych) oraz na rekultywowanych zwałach kopalnianych. Ponadto badano faunę Oribatida w przylegającym do zwału biotopie. Na 28 stanowiskach badawczych pobrano ogółem 5260 prób glebowych wykorzystanych do analizy zoocenologicznej, 224 próby służące do analiz glebowych i 1444 próby do oceny względnej wilgotności. Ogółem zebrano ponad 133 tysiące przedstawicieli mezofauny glebowej (roztoczy i skoczogonków), w tym ponad 73 tysiące reprezentantów rzędu Oribatida. Wyróżniono 3 stadia sukcesyjne w rozwoju zgrupowań Oribatida - „pionierskie”, „łąkowe” i „przedleśne”. Mechowce, mimo cech charakterystycznych dla „K-strategów”, możemy uznać za grupę, która z powodzeniem zasiedla hałdy. Mogą one osiągnąć zagęszczenie około 12 000 osobników/m2 po kilku latach i stają się dominującą grupą wśród mezofauny glebowej po 10-15 latach. Wśród gatunków zasiedlających zwały wyróżniono wczesnych kolonizatorów, a wśród nich tzw. „sprinterów” (np. Brachychochthonius cricoides, Liochthonius piluliferus, Scutovertex sculptus) oraz „długodystansowców” (np. Oppiella nova, Peloptulus phaenotus, Tectocepheus velatus), a także gatunki „późnej” sukcesji (np. Eupelops tardus, Punctoribates punctum, Tectocepheus minor). Do cech zoocenotycznych, które z największym prawdopodobieństwem pozwalają określić stadium rozwoju zgrupowania, należą między innymi: struktura dominacji, udział określonych kohort systematycznych, czy stadiów młodocianych wybranych gatunków. Bardzo różne czynniki środowiskowe (w pracy analizowano oddziaływanie ponad 20 parametrów glebowych i dotyczących roślin) w znaczący sposób wpływają na rozwój zgrupowań znajdujących się na poszczególnych stanowiskach na zwałach różnego typu. Zawartość niektórych pierwiastków, np. magnezu i sodu, najczęściej odnotowywano jako mającą największy wpływ na kształtowanie się zgrupowań. Ogólną charakterystykę zgrupowania mechowców (z wyjątkiem składu gatunkowego) można stosunkowo najłatwiej określić, opierając się na cechach roślinności występującej na danej powierzchni. Rodzaj składowanych odpadów nie wpływa w istotny sposób na strukturę czy skład gatunkowy zgrupowań mechowców. Oddziaływanie otaczających biotopów na skład gatunkowy i tempo rozwoju zgrupowań mechowców na zwałach było słabo zaznaczone. Zwykle połowa i więcej gatunków pojawiających się na hałdach była nieobecna w ich najbliższym otoczeniu. Pozytywny wpływ rekultywacji prowadzonej na zwałach jest zauważalny tylko w początkowym etapie rozwoju zgrupowań Oribatida. Po około 20 latach obserwuje się negatywne trendy w rozwoju fauny roztoczy, np. spadek zagęszczenia i liczby gatunków. Żaden z modeli sukcesji („ułatwiania”, „hamowania” czy „tolerancji”) nie wyjaśnia w sposób bezpośredni i pełny rozwoju fauny Oribatida. Niemniej jednak wydaje się, że model „ułatwiania” najlepiej opisuje większość zjawisk obserwowanych w odniesieniu do tej grupy zwierząt na zwałach poprzemysłowych. Zebrane mechowce należały do 172 gatunków Oribatida (co stanowi ponad 30% fauny Oribatida Polski), w tym 8 gatunków i 1 podgatunek były nowe dla fauny Polski, a 37 to gatunki nowe dla fauny Górnego Śląska

Czy polowania w dzisiejszym świecie mają rację bytu?

The impact of human activities on the planet has accelerated the loss of species and ecosystems to a level comparable to a sixth mass extinction, the first driven by a living species. The Living Planet Index, which measures biodiversity abundance levels, was reduced by 58 per cent between 1970 and 2012. Humans have already driven at least four of nine Earth system processes beyond their safe boundaries. Hunting has lost its original function (source of food and survival of people). However, hunters invoke various arguments, including ecological and ethical ones, for the maintenance of hunting. Scientific research, however, contradicts them, for example modern hunting is blamed for the disruption of natural mechanisms regulating the size of game populations. The answer to the arguments of hunting ethics is contemporary environmental ethics, in which the fundamental value is respect for life, for every form of existence. Recent research shows that overexploitation of the environment, including hunting and fishing, has the greatest negative impact on biodiversity

Rozwój fauny roztoczy na hałdach, czyli jak przyroda walczy z przemysłem

Mites, although tiny themselves, belong to the largest and most impressive lineage of animals, the arthropods. Over 45000 species of mites have been described and perhaps between 0.5 and 1 million currently exist. They are studied by disproportionately few systematists, ecologists, ethologists or evolutionary biologists. Mites are excellent models for addressing questions of more general interest, e.g. the importance of biodiversity, transgenic release, biomonitoring, the evolution of host specificity and virulence, sexual selection or the limits of physiology and morphology. Soil is the habitat of many mites, where their role is invaluable. The colonization of postindustrial dumps by mites is particularly interesting from the ecological point of view. The author thoroughly investigated 18 different dumps. The abundance of oribatids exceeded usually several thousand of individuals per m2 and over 10 species occurred on young dumps (where the exploitation stopped several years ago). After 30 years the abundance (over 20000 per m2) and species richness (between 18 to 42 species) were 2–3 times lower than in the neighbouring natural habitats. The colonization of dumps contaminated with heavy metals proceeded at a significantly slower rate. Many pioneer species, characterized by different morphological and ecological features, were described. In the course of investigations 205 oribatid species were identified on dumps (40% of total oribatid fauna in Poland). 32 species were new for the Polish fauna and 43 were recorded for the first time from Upper Silesia