Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 96. (Budapest 2004)

Molnár, J., Erdei, B. ; Hably, L.: The transport of leaves and fruits - a taphonomical study of leaf litter

meter Hedera helix LINNAEUS, 1753 covered the area sparcely or densely varying from place to place. In the first 14 m the reason for the decrease of the leaf number of some trees in the spring quadrats was presumably the lack of an unbroken herbaceous layer, thus leaves could be moved relatively easily on the ground and this part of the sample plot was exposed to the wind to a higher degree resulting in higher wind velocity. Leaves falling to the Hedera cover on the ground were easily trapped by the twigs and creepers of Hedera and could not be easily removed by the wind. The decrease of the number of leaves of numerous species was probably in part due to the decay and fragmentation of their leaves. In the case of some species, however, there is an increase of leaf number since a part of their leaves fell after sampling in autumn. Comparison of the autumn and spring data set-The evaluation of the quadrat set in autumn by 18 m and by 18.75 m in spring is showed by Figs 16-17. Those trees the leaves or fruits of which were found in the autumn and spring quadrats are indicated with bold numbers. The leaves of 4 of the arboreal species growing inside the circle of 10 m radius (out of 13 species of the circle) did not occur in the quadrat set in autumn at the 18th m of the transection whereas in the quadrat set in spring at 18.75 m 3 species were not recorded. Consequently, in the sample taken in autumn 69% of the species was represented by their leaves, whereas in spring this value was higher, 77%. There were 525 leaves in the 'autum' and 141 in the 'spring' quadrat. This significant difference resulted in part from the inhomogenity of the herbaceous layer and in part from the fact that a considerable part of the leaves was fragmented and could not be clearly identified. Even the leaves of the 2.5 m high Malus hupehensis (PAMPANINI) REHDER, 1933 were recorded neither in the autumn nor in the spring quadrat, though, it was situated at a distance of 2.5-3 m from the quadrats. Similarly, a Crataegus mollis SCHEELE, 1848 tree of 10 m height and situated at a distance of 9 m was not represented in the autumn quadrat. The reason for it was presumably the late fall of its leaves and the lack or scarcity of the herbaceous layer. The Acer tataricum LINNAEUS, 1753 tree the leaves of which were recorded neither in autumn nor in spring was growing further from the quadrat than its height which may explain its absence. A Prunus serrulata LlNDLEY, 1830 tree was closer to the quadrat than its height, however, none of the quadrats contained its leaves. Prospects of a flora and vegetation reconstruction - By means of principal components analysis of the autumn and spring data sets the change of the distribution pattern of the quadrats and the prospects of a vegetation reconstruction were investigated (Figs 18-20). An "ideal" quadrat containing the leaves of all taxa of the sample plot was assigned (presence absence data were applied, quadrats - objects; species - variables). None of the quadrats contained all the species of the