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Vegetation structure and diversity of an ancient temperate deciduous forest in SW Denmark 总被引:2,自引:0,他引:2
Bolderslev Skov (113 ha) is the largest contiguous ancient forest remnant in Denmark. The forest has been preserved since
1998 as a strict non-intervention forest reserve. We studied vegetation structure, floristic gradients, and diversity of the
forest in 50 plots of 100 m2 placed according to a restricted random sampling design. Dominant tree species were Fagus sylvatica, Fraxinus excelsior, Tilia cordata and Quercus robur, which in most parts of the forest form a mixed canopy. Most stands appeared to be of moderate age, 55-80 years old, and
large old trees were rare. pH in association with light and thickness of the litter layer were the most important factors
in explaining floristic gradients in the forest. Soil moisture (dry to mesic) was not strongly correlated with DCA axes for
neither tree nor field layer, but had a significant effect on the distribution of a number of herb species. Forest structure
was not important in explaining species distributions. Field layer species richness showed a positive relationship with the
pH-gradient. At the scale of 1m2 plots we also found a highly significant negative relationship between field layer species richness and the plot-wise Ellenberg
indicator value for nitrogen availability. Structure of the tree layer had little effect on field layer species richness.
The mixed composition, long continuity, and presence of a high proportion of the regional species pool assigns a high conservation
value to Bolderslev Skov and makes it an important site for future studies of the dynamic properties, niche preferences, and
inter-specific competition of temperate deciduous forest species.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Overstorey Control of Understorey Species Composition in a Near-natural Temperate Broadleaved Forest in Denmark 总被引:1,自引:1,他引:0
Rikke P.?Thomsen Jens-Christian?SvenningEmail author Henrik?Balslev 《Plant Ecology》2005,181(1):113-126
Little is known about the importance of the forest overstorey relative to other factors in controlling the spatial variability
in understorey species composition in near-natural temperate broadleaved forests. We addressed this question for the 19 ha
ancient forest Suserup Skov (55°22′ N, 11°34′ E) in Denmark, one of the few old-growth temperate broadleaved forest remnants
in north-western Europe, by inventorying understorey species composition and environmental conditions in 163 100 m2 plots. We use unconstrained and constrained ordinations, variation partitioning, and Indicator Species Analysis to provide
a quantitative assessment of the importance of the forest overstorey in controlling understorey species composition. Comparison
of the gradients extracted by unconstrained and constrained ordinations showed that the main gradients in understorey species
composition in our old-growth temperate broadleaved forest remnant are not caused by variability in the forest overstorey,
but are related to topography and soil, edge effects, and unknown broad-scale factors. Nevertheless, overstorey-related variables
uniquely accounted for 15% of the total explained variation in understorey species composition, with the pure overstorey-related
(Rpo), topography and soil (Rpt), edge and anthropogenic disturbance effects (Rpa), and spatial (Rps) variation fractions being of equal magnitude. The forward variable selection showed that among the overstorey-related variables
understorey light availability and to a lesser extent vertical forest structure were most important for understorey species
composition. No unique influence of overstorey tree species identity could be documented. There were many indicator species
for high understorey light levels and canopy gap centres, but none for medium or low light or closed canopy. Hence, no understorey
species behaved as obligate shade plants. Our study shows that, the forest overstorey has a weak control of understorey species
composition in near-natural broadleaved forest, in contrast to results from natural and managed forests comprising both conifer
and broadleaved species. Nevertheless, >20% of the understorey species found were indicators of high light conditions or canopy
openings. Hence, variability in canopy structure and understorey light availability is important for maintaining understorey
species diversity. 相似文献
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