34 research outputs found

    Cönológiai hasonlósági mintázatok indikációs ereje genuszszintű taxonlisták és gyakorisági eloszlások alapján

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    Egy él?hely cönológiai állapotának értékelésére sokféle módszer és indikátor áll rendelkezésre. Közülük kiemelked? gyakorlati ökológiai jelent?sége lehet azoknak, amelyek egyszer?ek, gyorsak, standardizálhatóak és megbízhatóak, illetve amelyek pontosan számszer?sítik az él?hely állapotát. Az egyik lehetséges módszer az él?helyen el?forduló, kisméret?, nagy abundanciájú és változatos ökológiai sajátságú nemzetségek (genuszok) vizsgálata. Az egyik legmegfelel?bbnek ítélt csoport erre a célra a talajlakó páncélosatkáké (Acari: Oribatida).&#x0D; Az MTA "Alkalmazkodás a klímaváltozáshoz" Kutatócsoportja bioindikációs módszertani kutatási programjához kapcsolódva, Oribatida talajatkákra vonatkozó, általunk felvételezett és irodalmi eredet? adatsorokon elemeztük a genuszszint? taxonlisták indikációs erejét, valamint a hasonlósági mintázatokat létrehozó f?bb mintázatgeneráló tényez?k hatását. Egy olyan módszertani eljárás kifejlesztése volt a cél, amelynek segítségével két tetsz?leges forrásból származó Oribatida genuszlista távolságfüggvényekkel kifejezett különböz?sége tér- és id?léptékeknek feleltethet? meg. Igazoltuk, hogy a genuszlisták az él?helyek térbeli távolságát is kifejezik. Módszerünkkel a bolygatott vagy átalakult él?helyek megváltozását az Oribatida közösségek, tér-id?beli távolságával tudjuk kifejezni.</jats:p

    Application of Oribatid mites as indicators

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    This review discusses the connection between quantitative changes of environmental factors and oribatid communities. With the overview of available studies, it can be clearly explored how various characteristics of Oribatid communities are modified due to changes in moisture, temperature, heavy metal concentration, organic matter content and level of disturbance. The most important question concerning the application of Oribatids as indicators is to clarify what kind of information content does natural Oribatid coenological patterns possess from the aspect of bioindication. Most of the variables listed above can be directly measured, since rapid methods are available to quantify parameters of the soil. Responses of Oribatids are worth to study in a more complex approach. Even now we have an expansive knowledge on how communities change due to modifications of different factors. These pieces of information necessitate the elaboration of such methods which render Oribatid communities suitable for the task to prognosticate what extent the given site can be considered near-natural or degraded, based on the Oribatid composition of a single sample taken from the given area. Answering this problem needs extensive and coordinated work

    Oribatid mites (Acari : Oribatida) in microcosms-A review

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    Oribatid mites are one of the most abundant and species rich group in soil mesofauna. In spite of this, we have limited knowledge on the role they play in ecological processes. Since they are small like other mesofauna members and live a hidden life, their observation is difficult. Their life style, interactions with other organisms and role in soil decomposition processes can be investigated with laboratory experiments more exactly and effectively. While the literature of microcosm studies is very extensive, relatively few review papers have been written about the methodology of microcosm studies. The present review summarizes details of techniques that have been applied laboratory microcosms involving oribatid mites. It is shown what one should keep in mind in planning, composing and setting up a microcosm. Our comparative evaluation reveals how the laboratory experiments were maintained and manipulated and what kind of information was extracted. This methodological review can be useful in preparing microcosm experiments applied to other animal groups as well

    Oribatid assemblies of tropical high mountains on some points of the “Gondwana-Bridge” – a case study

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    This work is the first part of a series of studies, which introduces the methodological possibilities of coenological and zoogeographical indication and – following the climate, vegetation and elevation zones – the pattern-describing analysis of the main Oribatid sinusia of the world explored till our days.This current work is a case-study, which displays the comparison of 9 examination sites from 3 different geographical locations. On each location, three vegetation types have been examined: a plain rain-forest, a mossforest and a mountainous paramo. Analyses are based on the hitherto non-published genus-level database and coenological tables of the deceased János Balogh professor. Occurrence of 18 genera is going to be published as new data for the given zoogeographical region

    Indication strength of coenological similarity patterns based on genus-level taxon lists and prevalence distribution

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    Several methods and indicators can be used to evaluate the coenological state of a given habitat, the ones which can be created simply, quickly, standardizably and reliably and which can be used to exactly quantify the state of a given habitat in point of numbers can be of outstanding practical importance in ecology. One possible method is the examination of the genera which can be found in a given habitat in great abundance and have little number of species and various ecological characteristics. For this purpose one of the most appropriate groups is that of ground-dwelling oribatid mites (Acari: Oribatida). In our research, joining the bioindication methodological project of the “Adaptation to Climate Change” Research Group of the Hungarian Academy of Sciences, the indication strength of genus-level taxon lists and the effects of the main pattern-generating factors creating similarity patterns were analysed with the help of data series on oribatid mites collected by us and originating from literature. Our aim was to develop a method with the help of which the difference expressed with distance functions between two oribatid mite genus lists originating from any sources can correspond to spatial and temporal scales. Our results prove that these genus lists are able to express the spatial distance of the habitats. With the help of this base of comparison changes in disturbed or transformed habitats can be expressed by means of oribatid mite communities, with spatial and temporal distances

    Seasonal change of oribatid mite communities (Acari, Oribatida) in three different types of microhabitats in an oak forest

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    Oribatid mites are one of the most abundant groups of the ground-dwelling mesofauna. They can be found in almost every terrestrial habitat all over the world and they are characterized by great species richness and great number of individuals. In spite of that not enough is known about their behaviour on community level and their spatial and temporal pattern in different habitats of the world. In our present study the seasonal behaviour of oribatid mite communities was analysed in three types of microhabitats in a temperate deciduous forest: in leaf litter, soil and moss. Samples were collected at a given site in a year and a half and the oribatid mite communities living there were studied on genus level along with the changes of meteorological factors characteristic of the area. The results show that corresponding to similar previous researches, the communities in our study do not have a seasonally changing, returning pattern either. Based on this, we can conclude that climatic differences and differences in other seasonally changing factors between the seasons do not have a significant role in the annual change of communities. Besides that we discovered that the communities of the three microhabitats are not completely the same. It is the oribatid mite community of the moss which differs mostly from communities in the leaf litter and in the soil. Our study calls attention among others to the fact that compositional changes of the oribatid mite communities living all over the world and their causes are unclear to date

    A klímaváltozás közösségökológiai hatásainak elemzései

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    A klímaváltozás ökológiai hatásainak elemzésével kapcsolatos tudományos eredményeink megközelítési módjukat tekintve az alábbi hat fő csoportba oszthatók: 1. Az elméleti várakozások tisztázása stratégiai modellezéssel. 2. Lehetséges hatások mértékének behatárolása Magyarország vonatkozásában, földrajzi analógiai megközelítéssel. 3. Nagy monitoring adatbázisok elemzései a már bekövetkezett változási tendenciák feltárására. 4. Természetközeli populációk és ökoszisztémák várható változásainak elemzése taktikai modellezéssel és statisztikai elemzésekkel. 5. A klímaváltozás agroökoszisztémákra gyakorolt hatásai 6. Új, hatékony és a korábbiaknál általánosabban használható bioindikátor-rendszer kidolgozása. A továbbiakban eredményeinket ezen felosztás szerinti csoportosításban ismertetjük

    A general framework for analyzing beta diversity, nestedness and related community-level phenomena based on abundance data

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    We describe a procedure for evaluating the relative importance of beta diversity, nestedness, and similarity properties of ecological data matrices containing density, cover or biomass scores of species. Our goals are achieved by extension of the simplex approach – originally proposed for presence–absence data – to abundances. Basically, the method involves decomposition of the Marczewski–Steinhaus coefficient of dissimilarity between pairs of sites into two fractions, one derived from differences between total abundance and the other from differences due to abundance replacement. These are contrasted by the similarity function counterpart, known as the Ruzicka coefficient, and are displayed graphically using ternary (or 2D simplex) plots. Interpretation is aided by calculating percentage contributions from these components to the (dis)similarity structure. Measures of replacement and nestedness are new for abundance data; these are considered complementary phenomena reflecting antithetic ecological processes that are analogous to those operating at the presence–absence level. The method is illustrated by artificial data and a range of actual ecological data sets representing different groups of organisms, different scales and different types of data. While the simplex diagrams and associated coefficients are meaningful by themselves, their comparison with presence–absence based results gives additional insight into data structure and background factors
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