Talaj tápanyag- és toxikus elemtartalom horizontális átrendeződési törvényszerűségeinek vizsgálata mintavízgyűjtőn = Study of horizontal migration tendencies of fertilizer and toxic elements in soils of a catchment area

Kutatásunk során a Velencei-tó 14 km2 nagyságú vízgyűjtőjén végeztünk vizsgálatokat. Mikro szinten parcellákon lejtő menti talajerózió modellezést végeztünk az E2D szoftver segítségével, térképezéssel feltártuk a csapadék eseményhez kötődő térbeli elemátrendeződési tendenciákat, üledékcsapdák kihelyezésével vizsgáltuk az egyes csapadékeseményekhez kötődően az elemfeldúsulást (ER) az erózióval mozgó szedimentben. Mezo szinten a vízgyűjtő egészén modelleztük a talajeróziót E3D szoftverrel, megszerkesztettük a kiindulási tápanyag térképeket, majd modelleztük a vízgyűjtőre a csapadék események hatására bekövetkező tápanyagmozgást. Üledékcsapdás elemzéseink azt mutatják, hogy minden vizsgált paraméter tekintetében a talajban mért koncentrációt meghaladó a lemosódó szedimentben mért elemkoncentráció. A szervesanyag tartalom esetében ER=2.1-szeres, míg a leiszapolható rész esetében csupán átlagosan ER=1,2-szoros feldúsulás jellemző. A mikroelemek közül a leginkább a Ni (ER=2,1), Zn (ER=1,2) és a Cu (ER=1,15) dúsul. A tápanyag veszteség térképeket vizsgálva megállapítható, hogy annak térbeli alakulását nem a kiindulási tápanyag térképben fellelhető különbségek határozzák meg, azt felül rajzolják a jellemző eróziós viszonyok. A területre jellemző átlagos Zn elmozdulás 14,26 mg/m2. Az AL-P2O5 lemosódás főként a környező területeknél magasabb P tartalommal rendelkező szántókon jelentős. Az átlagos AL-P2O5 kimosódás a vizsgált két csapadék eseménynél 5,5 - 15,05 mg/m2. | During our research we carried out examinations on two scales in the catchment area of a Lake Velence. We carried out soil erosion modelling along the slopes with the help of the E2D software, and examined enrichment ratios (ER) in the erosive sediment due to rainfall events by setting up sediment collectors. Taken the whole catchment area into consideration we modelled soil erosion with E3D software, we constructed the initial nutrient maps, and we modelled nutrient transport in the catchment area due to rainfall events. Our analyses of the sediment collectors show that the element concentration measured in the washed-off sediment exceeds the concentration in the soil in case of every studied parameter. The enrichment ratio of the organic matter is ER=2.1, while that of the silt+clay content is ER=1,2 on average. Microelements Ni (ER=2,1), Zn (ER=1,2) and Cu (ER=1,15) enrich most. Studying the nutrient loss maps it can be stated that its spatial change is determined not by the differences in the initial nutrient map, but by erosional conditions. The average Zn change characteristic of the area is 14,26 mg/m2. AL-P2O5 wash-off is significant mainly in arable lands with higher phosphorus content than the surrounding areas. The average AL-P2O5 wash-out during the two studied rainfall events was 5,5 - 15,05 mg/m2

A táji mintázatok kvantitatív elemzése = quantitative analysis of land mosaics

A projekt keretében a táji mintázatok elemzése - hazai vonatkozásban - két méretarányban történt meg. A beszámoló e két problémakör keretében elvégzett vizsgálatról ad számot. A kutatás egyrészt arra keresett választ, hogy a tájalkotó tényezők mintázatai miként integrálódnak és miként formálnak táji alakzatokat (hosszabb időtávon tekintve ez úgy fogalmazható meg, hogy a táji szerkezetek miként hatnak a táji folyamatokra), másrészt elemeztük, hogy a mintázatok a különböző antropogén hatásokra miként változtatják meg a mintázatot, milyen a táji metrikában is jelentkező módosító hatásokat lehet felismerni. | Landscape metrics act as the quantitative link between landscape patterns and ecological or environmental processes. The mosaical nature of the landscape is well known since 60?-ies.The metrics of patterns (eg. the perimeter, the area of a patch, their ratio) is typical for a landscape, which describes quantitativly the structure. The interactions among patches modify these structure, and using the landscape metrics technology, the depths and direction of landscape changes will measurable. The ability to quantify landscape structure is prerequisite to the study of landscape function and change. For this reason, much emphasis has been placed on developing methods to quantify landscape structure

Spatial distribution of bivalves in relation to environmental conditions (middle Danube catchment, Hungary)

The spatial distribution of bivalves in relation to environmental conditions was studied along a second- and third order stream – medium-sized river (River Ipoly) – large river (River Danube) continuum in the Hungarian Danube River system. Quantitative samples were collected four times in 2007 and a total of 1662 specimens, belonging to 22 bivalve species were identified. Among these species, two are endangered (Pseudanodonta complanata, Unio crassus) and five are invasive (Dreissena polymorpha, D. rostriformis bugensis, Corbicula fluminea, C. fluminalis, Anodonta woodiana) in Hungary. The higher density presented by Pisidium subtruncatum, P. supinum, P. henslowanum and C. fluminea suggests that these species may have a key role in this ecosystem. Three different faunal groups were distinguished but no significant temporal change was detected. The lowest density and diversity with two species (P. casertanum and P. personatum) occurred in streams. The highest density and diversity was found in the River Ipoly, in the side arms of the Danube and in the main arm of the Danube with sand and silt substrate, being dominated by P. subtruncatum and P. henslowanum. Moderate density and species richness were observed in the main arm of the Danube with pebble and stone substrate, being dominated by C. fluminea and S. rivicola. Ten environmental variables were found to have significant influence on the distribution of bivalves, the strongest explanatory factors being substrate types, current velocity and sedimentological characteristics.The project was financially supported by the Hungarian Scientific Research Fund under the contract No. OTKA T/046180. Special thanks to the DanubeIpoly National Park for the help in field work.info:eu-repo/semantics/publishedVersio

Biological flora of Central Europe Himantoglossum adriaticum H. Baumann

Himantoglossum adriaticum H. Baumann is a long-lived perennial orchid with an adriato-mediterranean distribution. The species-level separation of this species from the more geographically widespread H. hircinum has only recently been confirmed via a combination of molecular and morphometric techniques, which are further developed here. To provide a comprehensive overview of its autecology we integrated previously published information with extensive unpublished data derived mainly from populations in the Keszthely Hills of Hungary. In this paper we assess the distribution, habitat preferences, life history and seed germination (ex situ and in situ) of H. adriaticum, with special emphasis on its reproductive biology

Massive mortality of invasive bivalves as a potential resource subsidy for the adjacent terrestrial food web

Large-scale mortality of invasive bivalves was observed in the River Danube basin in the autumn of 2011 due to a particularly low water discharge. The aim of this study was to quantify and compare the biomass of invasive and native bivalve die-offs amongst eight different sites and to assess the potential role of invasive bivalve die-offs as a resource subsidy for the adjacent terrestrial food web. Invasive bivalve die-offs dominated half of the study sites and their highest density and biomass were recorded at the warm water effluent. The density and biomass values recorded in this study are amongst the highest values recorded for aquatic ecosystems and show that a habitat affected by heated water can sustain an extremely high biomass of invasive bivalves. These mortalities highlight invasive bivalves as a major resource subsidy, possibly contributing remarkable amounts of nutrients and energy to the adjacent terrestrial ecosystem. Given the widespread occurrence of these invasive bivalves and the predicted increase in the frequency and intensity of extreme climatic events, the ecological impacts generated by their massive mortalities should be taken into account in other geographical areas as well.The authors are grateful to David Strayer for valuable comments on a previous version of the manuscript. Special thanks to the Danube-Ipoly National Park for the help in field work. Ronaldo Sousa was supported by the project "ECOIAS" funded by the Portuguese Foundation for the Science and the Technology and COMPETE funds (contract: PTDC/AAC-AMB/116685/2010)

Impact of Dreissena fouling on the physiological condition of native and invasive bivalves : interspecific and temporal variations

The impact of Dreissena fouling on unionids has hardly been studied in Europe, despite the fact that in some ecosystems (e.g. Lake Balaton, Hungary) infestations of several hundreds to a thousand individuals per unionid have been observed. At present, the zebra mussel Dreissena polymorpha is a dominant species in Lake Balaton and in the last decade three other invasive bivalves were introduced, potentially increasing the pressure on native unionid survival. We examined whether the fouling of dreissenids (zebra and quagga (D. rostriformis bugensis) mussels) has a negative impact on native (Anodonta anatina, Unio pictorum and U. tumidus) and invasive (Corbicula fluminea and Sinanodonta woodiana) bivalves and whether there are any interspecific and temporal variations in fouling intensity and physiological condition measured by standard condition index and glycogen content. A significant negative impact was detected on native unionids only in July and September (no impact was detected in May), when the fouling rate was high. For invasive species, a significant negative impact was detected on S. woodiana with a high level of dressenid infestation; whereas no significant impact was detected on C. fluminea. Overall, this study confirms that Dreissena may threaten unionid species including the invasive S. woodiana, although high interspecific and temporal variations were observed. This situation should be taken into account in future ecological and conservational assessments because species respond differently to Dreissena fouling and effects seem to be more pronounced in late summer/early autumn. In addition, this study provides the first evidence that the invasive C. fluminea appear to be less vulnerable to dressenid fouling.The study was supported by the Hungarian Scientific Fund (KTIA-OTKA) under the contract No. CNK80140

The influence of the landscape structure within buffer zones, catchment land use and instream environmental variables on mollusc communities in a medium-sized lowland river

The world’s freshwater molluscan fauna is facing unprecedented threats from habitat loss and degradation. Declines in native populations are mostly attributed to the human impact, which results in reduced water quality. The objectives of our survey were to analyse the structure of the mollusc communities in a medium-sized lowland river and to determine the most important environmental variables at different spatial scales, including landscape structure, catchment land use and instream environmental factors that influence their structure. Our survey showed that a medium-sized river, that flows through areas included in the European Ecological Natura 2000 Network Programme of protected sites, provides diverse instream habitats and niches that support 47 mollusc species including Unio crassus, a bivalve of Community interest, whose conservation requires the designation of a special conservation area under the Habitats Directive Natura 2000. This survey showed that mollusc communities are impacted by several environmental variables that act together at multiple scales. The landscape structure within buffer zones, catchment land use and instream environmental variables were all important and influenced the structure of mollusc communities. Therefore, they should all be taken into consideration in the future restoration of the river, future management projects and programmes for the conservation of biodiversity in running waters. The results of this study may be directly applicable for the rehabilitation of river ecosystems and are recommended to stakeholders in their future decision concerning landscape planning, monitoring species and their habitats, conservation plans and management in accordance with the requirements of sustainable development