Leaf Litter Redistribution and Relevant Ecological
Processes in a Temperate Hardwood Forest of Mt. Jumbong Area, Korea
Lee, Dowon and
Sinkyu Kang
Graduate School of Environmental Studies, Seoul
National University, Korea
A
temperate hardwood forest of Mt. Jumbong, dominated by Quercus mongolica,
Acer pseudo-sieboldianum and Carpinus cordata,
consists of three distinct types of patches which are visually characterized by
aspect and understory plants. Two patch types are located on the southwest-facing
slopes: one with understory dominated by herbaceous plants (Patch S), and the
other covered with evergreen dwarf bamboo, Sasa borealis (Patch
SS). The third patch type is on the opposite slopes with understory dominated
by herbaceous plants (Patch N).
In
the forest, soil temperature and moisture availability appeared to favor soil
biological activities in Patch N, compared to the others. Relatively large
amount of leaf litter accumulated in Patch N due to the movement of litter from
the opposite southern slope, especially from Patch S, which might be related to
topography and direction of influential wind. Leaf litter was retained by thick
snowpack in Patch N from late fall to early spring while dwarf bamboo was
responsible for trapping and/or retention of leaf litter in Patch SS. Although
earlier greenness was observed in the southern aspect than in the northern
aspect, canopy might be less effective in governing litter redistribution and
processes in the forest floor and soil layers than understory.
It
is speculated that crucial ecosystem processes may be influenced by the
redistribution of leaf litter on the patchy soil environment of forest floor.
The results and their ecological implications are summerized as follows:
1. A
large amount of leaf litter was transported from the southwest-facing slope to
the northeast facing slope, suggesting that leaf litter can move over the
watershed boundary in a region subjected to strong wind, and that litter
dynamics should be considered in nutrient budget estimation, especially in
small forested watersheds.
2. Aspect
and understory exerted an influence on redistribution and decomposition of leaf
litter and that the effects could be different among the plant species.
3. The
leaf litter redistribution resulted in spatial heterogeneity of soil metal
contents, which in turn seemed to control soil enzyme activities and thus other
nutrient processes.
4. The
redistribution of leaf litter was of significance to heterogeneous distribution
of soil respiration in the forest floor.
5. Spatial
heterogeneity of leaf litter redistribution may have effects on soil
temperature and moisture conservation, both of which are major factors
controlling biochemical processes.
6. The
subsequent substrate redistribution may also contribute to spatial
heterogeneity of detritus food change.
7. It
appeared that there were two fluxes of leaf litter input to stream in fall and
spring every year. It is hypothesized that adjacent streams may have some
interesting ecological processes to respond to the periodic inputs of leaf
litter.
Finally, we wonder what is a major factor governing the
heterogeneity of understory distribution in the forest floor, how it interacts
with climate, topography and substrate redistribution, and how significant it
is to ecological processes of other forest ecosystems. Spatial heterogeneity of
understory would be also related to that of canopy level and biogeochemistry at
a watershed level. The subject deserves further attention in the long-term
ecological research and comparative studies of ecosystems.