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The effectiveness of dispersers on seeds of Korean pine (Pinus koraiensis Siebold et Zuccarini) was investigated in three fragmented stands and one primary stand. The proportion of Korean pine trees was less than 7% in the fragmented stands but more than 90% in primary stand. Five estimates related seed dispersal (proportion of removed seeds, scatter-hoarded seeds, cache dynamics, dispersal distance and microhabitat) were assessed to see the effect of forest fragmentation on the probability of seed dispersal of Korean pine seeds. Our results indicated fast seed harvest of Korean pine by small rodents at the seed stations and no difference among the four stands. Scatter-hoarding rodents were potentially important in promoting natural regeneration of Korean pine as revealed by high proportion of seed removal (up to 50%), short seed lifetime from the seed release locations and lower proportion of seeds remained on the ground surface. Although a proportion of seeds were scatter-hoarded in fragmented stands, no seedling successfully established due to heavy predation. Dispersal distances were strongly left-skewed in fragmented stands, indicating that fragmentation is likely to be disadvantageous for longer distance dispersal. The effective dispersal was suffered from a very heavy cost as accompanied by a great portion of seed predation and lower level of scatter-hoarded seeds. Failing to see seedling establishment in fragmented stands rather than in primary stand indicated that fragmentation and deforestation have negative effects on dispersal behavior and consequently seed destination. Artificial tree plantation and pinecone protection are highly recommended for Korean pine regeneration.
The paper presents results acquired by an analysis of stand structure, regeneration processes and disturbance regime of a mixed natural forest located in the Carpathians (Central Slovakia). The data were collected on two permanent research plots located on different geological bedrocks (andesite and migmatites). Significant differences in the composition of the upper tree layer were observed among two types of geological bedrock. On the plot I (andesite), European ash (Fraxinus excelsior L.) occurred as a dominant component. An opposite situation was observed on the plot II (migmatites). The coexistence of beech (Fagus sylvatica L., spruce (Picea abies L. Karst.) and ash was recorded in the upper layer. The middle and lower layers were almost identical on both types of bedrock. The dominance of beech with the admixture of other tree species was observed. Regarding the structure of the present forest stand in relation to the structure of the gapmakers and natural regeneration, we observed a partial cyclical alternation of the tree species composition of this natural forest within the time span of several developmental cycles. The analysis of natural regeneration implied a crucial role of ungulates for the growth enforcement of ash individuals in the next generation of natural forest. Under the current condition, a negative trend in tree species diversity of the future generation of natural forest towards the dominance of beech was found.
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