Manganese dynamics in decomposing needle and leaf litter — a synthesis

The aim of the present synthesis paper was to determine whether concentration changes and net release of manganese (Mn), as related to accumulated litter mass loss, are related to initial Mn concentration, mean annual temperature (MAT), mean annual precipitation (MAP), and tree genus or species. We also examined whether limit values for decomposition are related to initial litter Mn concentration, MAT, and MAP. We compiled 84 foliar litter decomposition studies, conducted mainly in boreal and temperate forest ecosystems, for which Mn dynamics had been well documented. Manganese concentration and amount were related to accumulated litter mass loss at each sampling time for each single study, as well as for (i) all studies combined (n = 748) and (ii) for species groups viz. Norway spruce (Picea abies (L.) Karst.) (n = 284), pine (Pinus) species (n = 330), and deciduous species (n = 214). The changes in Mn concentration with accumulated mass loss followed quadratic functions showing significantly higher Mn concentrations for Norway spruce vs. Scots pine (Pinus sylvestris L.) (p < 0.0001) and vs. deciduous species (p < 0.01), as well as significantly higher for deciduous species vs. Scots pine (p < 0.0001). Manganese release rates were different among the three species groups (p < 0.001). Still, rates were related to initial Mn concentrations (p < 0.001) for all litter types combined and for the three species groups. Norway spruce released Mn more slowly than pine and deciduous species. Rates were related to climatic factors for litter of Norway spruce and deciduous species. Limit values for all litter and for pine species separately were related to Mn (p < 0.001) and MAT (p < 0.001). For Norway spruce, limit values were related to MAT (p < 0.001) and MAP (p < 0.01). It appears that Norway spruce litter retains Mn more strongly in the litter structure, producing humus richer in Mn than does litter of pine and deciduous species.

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Litter decomposition in a transect of Norway spruce forests: substrate quality and climate control

Canadian Journal of Forest Research ◽

10.1139/x00-044 ◽

2000 ◽

Vol 30 (7) ◽

pp. 1136-1147 ◽

Cited By ~ 83

Author(s):

Björn Berg ◽

Maj-Britt Johansson ◽

Vernon Meentemeyer

Keyword(s):

Mass Loss ◽

Norway Spruce ◽

Litter Decomposition ◽

First Year ◽

Lignin Concentration ◽

Litter Mass ◽

Substrate Quality ◽

Litter Mass Loss ◽

Mn Concentration ◽

Mn Concentrations

We used a climatic transect of 14 stands of Norway spruce (Picea abies (L.) Karst.) at which locally collected needle litters was incubated. Our purpose was to show that climate is not necessarily the main rate-regulating factor even in a long climatic transect. The sites are found in Sweden from 56 to 66°N. There was virtually no relationship between climate (AET ranging between 371 and 545 mm) and first-year mass loss (range 19.4-32.8%). Instead, substrate quality (litter Mn concentration) explained 27% of the site-to-site variation in first-year mass loss. For the later stages of decomposition (second to fifth year), the sites could be divided into two groups; one in which lignin concentration regulated litter mass-loss rates, and one in which lignin concentration was not an important control. In this latter group, Mn concentrations were the component best correlated with litter mass loss. When combining all data, Mn concentration gave the best linear relationship. We repeated this procedure using first- to fifth-year mass-loss values and found the same pattern. We concluded that litter Mn concentrations is a key factor for Norway spruce litter decomposition because of its influence on lignin degradation and that the very early stage is short or nonexistant.

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Litter mass-loss rates in late stages of decomposition in a climatic transect of pine forests. Long-term decomposition in a Scots pine forest. IX.

Canadian Journal of Botany ◽

10.1139/b95-163 ◽

1995 ◽

Vol 73 (10) ◽

pp. 1509-1521 ◽

Cited By ~ 82

Author(s):

Maj-Britt Johansson ◽

Björn Berg ◽

Vernon Meentemeyer

Keyword(s):

Mass Loss ◽

Scots Pine ◽

Actual Evapotranspiration ◽

The Arctic ◽

Decomposition Rates ◽

Lignin Concentration ◽

Arctic Circle ◽

Litter Mass ◽

Litter Mass Loss ◽

Loss Rates

We investigated rate-regulating factors for decomposition rates of Scots pine needle litter at 22 sites over a 2000-km long transect ranging from the Arctic Circle in Scandinavia to northern continental Europe. We found very different patterns for rate-regulating factors in the early stages of decomposition as compared to later stages (> 20% accumulated mass loss). The initial decomposition rates (measured over the 1st year) ranged from about 10.9%/year close to the Arctic Circle to about 43.7%/year in south Sweden. The dominant rate-regulating factor was climate (average annual temperature, and actual evapotranspiration), and none of the substrate-quality factors was significant. In the later stages, the annual mass loss varied from 2.2%/year to 41.5%/year. The rate-regulating factors were climate and the litter's concentration of lignin. We found that the effect of lignin concentration on litter mass-loss rate varied with site and this relative effect was negatively related with actual evapotranspiration. The effect of lignin concentration on mass-loss rates near the Arctic Circle was thus low (at low values for actual evapotranspiration) whereas in Southern Sweden and on the continent the rate-regulating effect of lignin was higher. Key words: foliar litter, decomposition, lignin, climatic transect, rate-regulating factors, climate change.

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Long-Term Effects of Climate and Litter Chemistry on Rates and Stable Fractions of Decomposing Scots Pine and Norway Spruce Needle Litter—A Synthesis

Forests ◽

10.3390/f13010125 ◽

2022 ◽

Vol 13 (1) ◽

pp. 125

Author(s):

Björn Berg ◽

Mikael Lönn

Keyword(s):

Mass Loss ◽

Norway Spruce ◽

Scots Pine ◽

Late Stage ◽

Early Stage ◽

Negative Relationship ◽

Mean Annual Precipitation ◽

Mean Annual Temperature ◽

Long Term Effects ◽

Limit Values

We have reviewed information on early-, late- and limit-value decomposition stages for litter of Norway spruce (Picea abies) and Scots pine (Pinus silvestris). This synthesis covers c 16 studies/papers made along a climatic gradient; range in mean annual temperature (MAT) from −1 to +7 °C and mean annual precipitation (MAP) from 425 to 1070 mm. Scots pine has an early stage dominated by carbohydrate decomposition and a late stage dominated by decomposition of lignin; Norway spruce has just one stage dominated by lignin decomposition. We used data for annual mass loss to identify rate-regulating factors in both stages; climate data, namely, MAT and MAP, as well as substrate properties, namely, nitrogen (N), acid unhydrolyzable residue (AUR), manganese (Mn). Early-stage decomposition for Scots pine litter was dominated positively by MAT; the late stage was dominated negatively by MAT, N, and AUR, changing with decomposition stage; there was no effect of Mn. Norway spruce litter had no early stage; decomposition in the lignin-dominated stage was mainly negative to MAP, a negative relationship to AUR and non-significant relationships to N and MAT. Mn had a positive relationship. Limit values for decomposition, namely, the accumulated mass loss at which decomposition is calculated to be zero, were related positively to Mn and AUR for Scots pine litter and negatively to AUR for Norway spruce litter. With different sets of rate-regulating factors as well as different compounds/elements related to the limit values, the decomposition patterns or pathways are different.

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Litter mass-loss rates in late stages of decomposition at some climatically and nutritionally different pine sites. Long-term decomposition in a Scots pine forest. VIII

Canadian Journal of Botany ◽

10.1139/b93-078 ◽

1993 ◽

Vol 71 (5) ◽

pp. 680-692 ◽

Cited By ~ 59

Author(s):

Björn Berg ◽

Charles McClaugherty ◽

Maj-Britt Johansson

Keyword(s):

Mass Loss ◽

Scots Pine ◽

Loss Rate ◽

Mass Loss Rate ◽

Climatic Conditions ◽

Initial Mass ◽

Lignin Concentration ◽

Litter Mass ◽

Litter Mass Loss ◽

Loss Rates

The patterns of some chemical changes and litter mass-loss rates were investigated for a variety of types of decomposing litter in pine forests under different climatic conditions and at sites with different nutrient status. A mixed deciduous forest was also compared. In initially chemically identical Scots pine needle litter incubated under different climatic conditions, the lignin concentration increased faster as a function of accumulated mass loss when the climatic conditions promoted a higher initial mass-loss rate. Also under artificially created conditions, e.g., after fertilization and irrigation, the same phenomenon occurred. Litter mass-loss rates decreased during decomposition as lignin concentrations increased. The relative decrease was significantly larger at sites with a climate that promoted an initially higher mass-loss rate. At the same lignin concentration, however, the mass-loss rate was significantly lower in drier and colder conditions, viz. climatic conditions that promote a lower initial mass-loss rate. Nevertheless, at very high lignin concentrations that lignin clearly dominated over climate as a rate-regulating factor. A possible consequence of this observation could be a higher rate of organic matter accumulation at sites that initially promote a high initial mass-loss rate for litter than at sites with conditions that give lower initial rates, at least for a given species of litter. Key words: litter, decomposition, lignin, chemical changes, climatic transect, effect of climate change.

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