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Greater accumulation of litter in spruce (Picea abies) compared to beech (Fagus sylvatica) stands is not a consequence of the inherent recalcitrance of needles.

Berger TW, Berger P - Plant Soil (2012)

Bottom Line: Litter decay indicated non-additive patterns, since similar remaining masses under pure beech (47%) and mixed beech-spruce (48%) were significantly lower than under pure spruce stands (67%).In contradiction to the widely held assumption of slow decomposition of spruce needles, we conclude that accumulation of litter in spruce stands is not caused by recalcitrance of spruce needles to decay; rather adverse environmental conditions in spruce stands retard decomposition.Mixed beech-spruce stands appear to be as effective as pure beech stands in counteracting these adverse conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Forest- and Soil Sciences, Institute of Forest Ecology, University of Natural Resources and Live Sciences (BOKU), Peter Jordan-Straße 82, 1190 Vienna, Austria.

ABSTRACT

Background and aims: Replacement of beech by spruce is associated with changes in soil acidity, soil structure and humus form, which are commonly ascribed to the recalcitrance of spruce needles. It is of practical relevance to know how much beech must be admixed to pure spruce stands in order to increase litter decomposition and associated nutrient cycling. We addressed the impact of tree species mixture within forest stands and within litter on mass loss and nutritional release from litter.

Methods: Litter decomposition was measured in three adjacent stands of pure spruce (Picea abies), mixed beech-spruce and pure beech (Fagus sylvatica) on three nutrient-rich sites and three nutrient-poor sites over a three-year period using the litterbag method (single species and mixed species bags).

Results: Mass loss of beech litter was not higher than mass loss of spruce litter. Mass loss and nutrient release were not affected by litter mixing. Litter decay indicated non-additive patterns, since similar remaining masses under pure beech (47%) and mixed beech-spruce (48%) were significantly lower than under pure spruce stands (67%). Release of the main components of the organic substance (Corg, Ntot, P, S, lignin) and associated K were related to mass loss, while release of other nutrients was not related to mass loss.

Conclusions: In contradiction to the widely held assumption of slow decomposition of spruce needles, we conclude that accumulation of litter in spruce stands is not caused by recalcitrance of spruce needles to decay; rather adverse environmental conditions in spruce stands retard decomposition. Mixed beech-spruce stands appear to be as effective as pure beech stands in counteracting these adverse conditions.

No MeSH data available.


Related in: MedlinePlus

Remaining mass (%) of exposed litter mixtures in single spruce (SP), mixed (mixed spruce, mSP; mixed beech, mBE) and single beech (BE) litter bags. Since bedrock did not affect remaining mass (see Table 4) a two-way ANOVA (factors incubation stand and litter mixture) was performed for each sampling date after 0.5, 1, 2 and 3 years. Plotted bars represent group means of each litter mixture (standard errors were calculated for N = 2 bedrocks ×3 incubation stands ×3 replications; sites =18) and different letters indicate significant differences between them (Duncan multiple range test, p < 0.05)
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Fig1: Remaining mass (%) of exposed litter mixtures in single spruce (SP), mixed (mixed spruce, mSP; mixed beech, mBE) and single beech (BE) litter bags. Since bedrock did not affect remaining mass (see Table 4) a two-way ANOVA (factors incubation stand and litter mixture) was performed for each sampling date after 0.5, 1, 2 and 3 years. Plotted bars represent group means of each litter mixture (standard errors were calculated for N = 2 bedrocks ×3 incubation stands ×3 replications; sites =18) and different letters indicate significant differences between them (Duncan multiple range test, p < 0.05)

Mentions: As expected, the remaining mass of incubated litter was primarily affected by the time of exposure (sampling date; Table 4). Additionally, mass loss (100 - remaining mass in %) was significantly affected both by incubation stand and to a minor extent by litter mixture according to given F-values. Surprisingly, the soil type (bedrock) did not influence decay at all. It is striking that these significant differences between the 4 individual litter components (litter mixture) did not vary with tree stand composition (incubation stand), since there was no interaction between these two factors. For that reason, the remaining masses of the individual litter mixtures (SP, mSP, mBE, Be) were plotted for each sampling date, averaged over bedrock and incubation stand (Fig. 1). For each sampling date mass loss did not differ between single and mixed spruce litter or between single and mixed beech litter, however beech decomposed slower than spruce. During the first two years admixed spruce needles tended to slow down decomposition of beech foliage while mixing both fractions increased decay of spruce needles after the first year.Table 4


Greater accumulation of litter in spruce (Picea abies) compared to beech (Fagus sylvatica) stands is not a consequence of the inherent recalcitrance of needles.

Berger TW, Berger P - Plant Soil (2012)

Remaining mass (%) of exposed litter mixtures in single spruce (SP), mixed (mixed spruce, mSP; mixed beech, mBE) and single beech (BE) litter bags. Since bedrock did not affect remaining mass (see Table 4) a two-way ANOVA (factors incubation stand and litter mixture) was performed for each sampling date after 0.5, 1, 2 and 3 years. Plotted bars represent group means of each litter mixture (standard errors were calculated for N = 2 bedrocks ×3 incubation stands ×3 replications; sites =18) and different letters indicate significant differences between them (Duncan multiple range test, p < 0.05)
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4372834&req=5

Fig1: Remaining mass (%) of exposed litter mixtures in single spruce (SP), mixed (mixed spruce, mSP; mixed beech, mBE) and single beech (BE) litter bags. Since bedrock did not affect remaining mass (see Table 4) a two-way ANOVA (factors incubation stand and litter mixture) was performed for each sampling date after 0.5, 1, 2 and 3 years. Plotted bars represent group means of each litter mixture (standard errors were calculated for N = 2 bedrocks ×3 incubation stands ×3 replications; sites =18) and different letters indicate significant differences between them (Duncan multiple range test, p < 0.05)
Mentions: As expected, the remaining mass of incubated litter was primarily affected by the time of exposure (sampling date; Table 4). Additionally, mass loss (100 - remaining mass in %) was significantly affected both by incubation stand and to a minor extent by litter mixture according to given F-values. Surprisingly, the soil type (bedrock) did not influence decay at all. It is striking that these significant differences between the 4 individual litter components (litter mixture) did not vary with tree stand composition (incubation stand), since there was no interaction between these two factors. For that reason, the remaining masses of the individual litter mixtures (SP, mSP, mBE, Be) were plotted for each sampling date, averaged over bedrock and incubation stand (Fig. 1). For each sampling date mass loss did not differ between single and mixed spruce litter or between single and mixed beech litter, however beech decomposed slower than spruce. During the first two years admixed spruce needles tended to slow down decomposition of beech foliage while mixing both fractions increased decay of spruce needles after the first year.Table 4

Bottom Line: Litter decay indicated non-additive patterns, since similar remaining masses under pure beech (47%) and mixed beech-spruce (48%) were significantly lower than under pure spruce stands (67%).In contradiction to the widely held assumption of slow decomposition of spruce needles, we conclude that accumulation of litter in spruce stands is not caused by recalcitrance of spruce needles to decay; rather adverse environmental conditions in spruce stands retard decomposition.Mixed beech-spruce stands appear to be as effective as pure beech stands in counteracting these adverse conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Forest- and Soil Sciences, Institute of Forest Ecology, University of Natural Resources and Live Sciences (BOKU), Peter Jordan-Straße 82, 1190 Vienna, Austria.

ABSTRACT

Background and aims: Replacement of beech by spruce is associated with changes in soil acidity, soil structure and humus form, which are commonly ascribed to the recalcitrance of spruce needles. It is of practical relevance to know how much beech must be admixed to pure spruce stands in order to increase litter decomposition and associated nutrient cycling. We addressed the impact of tree species mixture within forest stands and within litter on mass loss and nutritional release from litter.

Methods: Litter decomposition was measured in three adjacent stands of pure spruce (Picea abies), mixed beech-spruce and pure beech (Fagus sylvatica) on three nutrient-rich sites and three nutrient-poor sites over a three-year period using the litterbag method (single species and mixed species bags).

Results: Mass loss of beech litter was not higher than mass loss of spruce litter. Mass loss and nutrient release were not affected by litter mixing. Litter decay indicated non-additive patterns, since similar remaining masses under pure beech (47%) and mixed beech-spruce (48%) were significantly lower than under pure spruce stands (67%). Release of the main components of the organic substance (Corg, Ntot, P, S, lignin) and associated K were related to mass loss, while release of other nutrients was not related to mass loss.

Conclusions: In contradiction to the widely held assumption of slow decomposition of spruce needles, we conclude that accumulation of litter in spruce stands is not caused by recalcitrance of spruce needles to decay; rather adverse environmental conditions in spruce stands retard decomposition. Mixed beech-spruce stands appear to be as effective as pure beech stands in counteracting these adverse conditions.

No MeSH data available.


Related in: MedlinePlus