Content of the Volume 40.
Körmöczi, L. and Varró, Cs.: bord-ER - computer program for performing moving split-window analysis.
Cseh, V., Kiss, M. and Tanács, E. (2014): Carbon sequestration of floodplain forests: a case study from Hungary, Maros river valley. — Tiscia 40, 3-10
Abstract. Model-based assessment of the carbon storage potential of different types of forests is an important task in the context of climate change and green infrastructure development goals. In our paper, we present the results of the calculations aimed at comparing carbon sequestration processes of floodplain forests with different ages and management intensities in the active floodplain of the Maros river (South East Hungary). These types of assessments can help in resolving the complex environmental management issues of these areas, characterized mainly by the conflicting interests of the forestry, water management and nature conservation sectors. The work was carried out using the CO2Fix3.2 model, based on the field database of a forest reserve and the forest inventory of the area. The main forest types are native and non-native willow-poplar stands, managed and non-managed hardwood forests (with pedunculate oak and elm species) and stands of invasive species. The results highlight the importance of managed forests with long rotation cycle and old-growth unmanaged forests from the point of view of carbon sequestration. They also draw attention to the necessity of incorporating these ecosystem services in the planning processes for a better environmental decision-making.
Key words: carbon stock modelling, CO2Fix, management intensity, willow-poplar forests, floodplain forests, Maros valley
Erdős, L. (2014): Post-fire regeneration of a forest-steppe: vegetation status 20 years after the fire event. — Tiscia 40,11-15
Abstract. Fires played an important role in the natural dynamics of the forest-steppes, but human activity has modified the regeneration capacity of the vegetation: for example, post-fire immigration of the native species is less efficient, due to habitat fragmentation. On the other hand, alien species (including invasives) are positively affected by fires. During the past few decades, several human-induced fires happened in the sandy forest-steppes of the Danube-Tisza Interfluve. Unfortunately, little is known about the regeneration processes. My aim was to compare two neighbouring forest-steppe segments, one of which burned down in 1996, the other remained intact. I prepared coenological relevés in both segments, and compared them, based on PCoA-ordination, differential species, species number, social behaviour types, species’ coenological preferences and species’ light requirement. The ordination and the social behaviour type spectra suggested that, almost two decades after the fire event, differences are not very pronounced any more. However, there were more light-demanding species in the burned section. The explanation for this may be that the canopy layer became more open due to the fire. The fire increased the species number of the forest patches, but this was partly due to the alien species. It can be concluded that, although fires had an important role in the natural dynamics of forest-steppes, and the regeneration may be fast, fires are hazardous at persent. If invasives occur in the region, there is a high risk that they become more abundant.
Key words: dynamics, resilience, alien species, Emlékerdő.
Lőrinczi, G. (2014): Some notes on the tool-using behaviour of the ant, Aphaenogaster subterranea (Hymenoptera: Formicidae). – Tiscia 40,17-23
Abstract. Ants of the genus Aphaenogaster lack the ability to ingest and carry large volumes of liquid food and share it through trophallaxis with other colony members in the nest. Nevertheless, these species have developed a complex method to compensate for these deficiencies by using debris as tools to transport liquid food back to the colony. In the present study, I investigated the tool-using behaviour of Aphaenogaster subterranea in retrieving food through field observations using honey and petroleum jelly baits. Similarly to other members of its genus, the tool-using behaviour of the foraging workers of A. subterranea consisted of three distinct components at honey baits, dropping tools into the liquid food, adjusting the position of tools brought by other workers, and transporting the food-soaked tools back to the colony. The proportion of tool-using workers constituted only a small fraction of the total number of workers that were observed at baits, however, the number of workers manipulating tool items was positively correlated with the number of workers performing other activities. Materials most commonly used as tools were particles of soil and easily moveable, broken fragments of plant materials (e.g., bits of pine needle, cone and bark). Tool-using workers also dropped some debris into petroleum jelly, a non-food substance presenting a potential hazard of drowning or becoming entangled, at 60% of the baits, however, at a significantly lower intensity than in the case of honey. Adjusting or removing tool items soaked with petroleum jelly, on the other hand, was never observed.
Key words: Aphaenogaster subterranea, food transport, foraging, tool use.
Körmöczi, L. and Varró, Cs. (2015): bord-ER – computer program for performing moving split-window analysis. – Tiscia 40, 25-30
Abstract. Vegetation ecologists and soils scientists frequently use moving split-window analysis for partitioning transect data, and reveal boundaries. Few existing softwares supported this research activity, but non of them was equipped with statistical significance test. A new software was developed to mitigate this shortcoming. We offer a user-friendly tool with five distance/dissimilarity functions and two types of random reference. This paper is a short description of the program.
Key words: boundary analysis, C-program, statistical test, user manual.