Kisemlős populációk paramétereinek becslése és modellezése
This dissertation contains the results of small mammal studies performed at the University of Pécs and small mammal population level monitoring of distinguished habitats along Drava river with support from Duna-Drava National Park. Small mammal research in the Drava Lowlands had been started well be...
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| Dokumentumtípus: | Disszertáció |
| Megjelent: |
2009-05-21
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| Tárgyszavak: | |
| mtmt: | 2858511 |
| Online Access: | http://doktori.ek.szte.hu/1258 |
| Tartalmi kivonat: | This dissertation contains the results of small mammal studies performed at the University of Pécs and small mammal population level monitoring of distinguished habitats along Drava river with support from Duna-Drava National Park. Small mammal research in the Drava Lowlands had been started well before co-ordinated biodiversity monitoring was launched or Duna-Drava National Park was established: small mammals have been trapped in a variety of habitats since 1994. Our research history thus covers more than a decade, including data series spanning several years as well as samplings with data form shorter periods in habitats of the upper Drava reach. The present dissertation summarises the results of our small mammal investigations on the basis of two synbiological aspects (population biological and demographic changes, survival estimation and modelling). In the first subject we dealt with the population dynamics of common species, demographic changes and the estimation of population size. Secondly, in addition to analysing and estimating abundance and its changes over time, the dissertation deals also with survival estimation and modelling, which comprise one of the most speedily developing subjects of population biology. Part of this research can be regarded, most of all, as syn-phenobiological investigation, as we have revealed synbiological phenomena, and analysed the temporal-spatial changes of certain population biological characteristics. In several cases, however, we evaluated our data in respect of various background variables (e.g. weather factors, physiognomy of the vegetation in the analysed habitats), thus the revealed phenomena could be scrutinised in a causal interrelation. The synbiological analysis and monitoring of small mammals was performed between 1994-2007 in habitats of Baranya and Somogy counties, along river Drava. The first sample area was selected in 1994 in Baranya, in a lowland oak-hornbeam forest habitat where small mammal studies were then continued for 10 years. In 1997 we performed the small mammal fauna survey of a mosaic habitat beside the Matty lake in the lower Drava section, which was followed by the analysis of the spatial and temporal pattern of small mammals in this lakeside habitat with heterogeneous vegetation for another six years. As a separate programme beside regional and national level projects of the Hungarian National Biodiversity Monitoring System, the biological monitoring of the upper Drava reach was launched, as part of which we started the monitoring of small mammal populations in 2000, in additional habitats. Two sampling sites were selected in Lankóci-forest near Gyékényes, differing from each other in their vegetation structures (a strictly protected, closed alder gallery forest, and a neighbouring reforested area. Furthermore, trappings were performed in 2007 along the upper Drava reach in Croatia, where the small mammals of Repas forest, a lowland oak-ash-elm gallery forest located in a higher terrain than the floodplain, this habitat type representing at the same time areas under forestry management. The method applied in each of the sampling areas was capture-mark-recapture, with the same box-type live-traps (75x95x180 mm). Just like the traps themselves, the trapping technique was also alike in all cases: bacon and cereals mixed with aniseed extract and vegetable oil were used as bait. The traps were checked twice daily in each of the forest habitats (Bükkhát-forest, Lankóci-forest, Repas-forest): from 700 in the morning and from 1900 in the evening, with the traps being left triggered during the day, because they did not heat up considerably inside the forest. However, the traps were left open for the day hours in the summer period beside the Matty lake, thus we had data from the morning trap checking sessions that resulted from greater nocturnal small mammal activity. The same code table was used for marking in all the sample areas. A separate database system was developed under Microsoft Access for storing and processing multiple capture and recapture data. SQL filtering of capture-recapture data made it possible or us to organise and process our data in a versatile and effective way. Each record of the database corresponds with data of one captured individual (either marked or unmarked), and the structure of its attributes, fields and associations with other data tables can be continuously widened. The long-term temporal patterns of population dynamics were analysed in the case of yellow-necked wood mouse (A. flavicollis), sriped field mouse (A. agrarius) and bank vole (C. glareolus) populations, all being frequent species in the Bükkhát-forest. Our long-term trapping survey between 1994-2003 was suitable for the analysis of demographic fluctuations of these frequent species, for which purpose we used the “minimum number alive” (MNA) values standardised for 100 trap nights. Based on the monthly values of this population index, cyc |
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