scholarly journals 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 ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 125
Author(s):  
Björn Berg ◽  
Mikael Lönn

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.

2013 ◽  
Vol 43 (12) ◽  
pp. 1127-1136 ◽  
Author(s):  
Björn Berg ◽  
Björn Erhagen ◽  
Maj-Britt Johansson ◽  
Lars Vesterdal ◽  
Mikaeel Faituri ◽  
...  

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.


2013 ◽  
Vol 43 (1) ◽  
pp. 103-107 ◽  
Author(s):  
Björn Berg ◽  
Chunjiang Liu ◽  
Ryszard Laskowski ◽  
Matthew Davey

Using literature data, we investigated coniferous and broadleaf litter from 58 tree species using a database encompassing concentrations of N and acid-unhydrolyzable residue (AUR) (gravimetric lignin) in newly shed litter, mean annual temperature, and mean annual precipitation. Our aims were to (i) demonstrate any large-scale relationships between concentrations of N and AUR in foliar litter and (ii) determine differences in this respect among litter from Pinus and Quercus. To this end, we had collected foliar litter data for Asia and Europe, forming a climate gradient. Litter from broadleaf and coniferous trees differed significantly in concentrations of N (p < 0.0001, 9.64 versus 5.50 mg/g, respectively) and AUR (p < 0.0001, 219 versus 292 mg/g, respectively). There were highly significant positive linear relationships between concentrations of N and AUR for broadleaf (p < 0.0001) and coniferous litter (p < 0.0001). There were also significant positive relationships for AUR as a function of N concentration for the genera Pinus and Quercus but not within species. That for Scots pine (Pinus sylvestris L.) was negative and that for common oak (Quercus robur L.) not significant.


1987 ◽  
Vol 17 (8) ◽  
pp. 783-786 ◽  
Author(s):  
Karl-Anders Högberg

Surface planting and deep planting were compared with respect to water uptake and root development in the early stage of field establishment. The material consisted of containerized Scots pine (Pinussylvestris L.) and Norway spruce (Piceaabies (L.) Karst.) seedlings. For both species, surface planted seedlings showed less root egress 5 weeks after planting compared with deep planted. Needle conductance was lower for surface planted than deep planted pine seedlings. For pine seedlings high correlation was found between root egress and needle conductance 5 weeks after planting for surface planting but not for deep planting. It is concluded that surface planting increases the water stress risk during establishment. Evaporative water loss from the root ball and the upper soil layers is discussed as the main cause to this effect.


2001 ◽  
Vol 31 (6) ◽  
pp. 988-998 ◽  
Author(s):  
Björn Berg ◽  
Charles McClaugherty ◽  
Amalia Virzo De Santo ◽  
Dale Johnson

This synthesis paper presents a model for estimating the buildup of soil organic matter in boreal deciduous and coniferous forests. A basic model was developed using data from a well-studied Scots pine (Pinus sylvestris L.) forest (SWECON site) and based on limit values for litter decomposition and amounts of litter fall. A local validation gave a calculated humus accumulation that differed by 8% from the amount measured in the stand. This model was further validated using data for humus accumulated for 2984, 2081, and 1106 years, predicting an accumulation close to the measured amount, and for needle litter the missing fractions were 16, 17, and –6%, respectively, for the three groups. The limit value for litter decomposition is negatively related to the litter's initial N concentration; thus, N-rich litter should have a larger resistant fraction left than N poor. This relationship was validated using nine paired stands of monocultures: eight pairs of Scots pine and Norway spruce (Picea abies (L.) Karst.) and one pair of red alder (Alnus rubra Bong.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). The measured amount of SOM was related to foliar litter fall and its N concentration. In all cases the more N-rich litter gave in all cases the more N-rich Norway spruce litter gave a significantly higher accumulation of humus for Norway spruce in spite of a higher litter fall for Scots pine. Also, red alder gave more SOM than Douglas-fir and in an expected relation to the litter N concentration. A consequence of this would be that C sinks of different efficiencies or capacities would tend to accumulate SOM at different rates.


BioResources ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 356-372 ◽  
Author(s):  
Olov Karlsson ◽  
Ekaterina Sidorova ◽  
Tom Morén

Studies on the durability and dimensional stability of a series of hardwoods and softwoods after thermal modification in vegetable oils and in steam atmospheres have been performed. Mass loss after exposure to Coniophora puteana (BAM Ebw.15) for 16 weeks was very low for European birch, European aspen, Norway spruce, and Scots pine thermally modified in a linseed oil product with preservative (for 1 hour at 200 oC). Fairly low mass losses were obtained for wood thermally modified in linseed-, tung- and rapeseed oil, and losses were related to the wood species. Low mass loss during rot test was also found for Norway spruce and Scots pine modified in saturated steam at 180 oC. Water absorption of pine and aspen was reduced by the thermal treatments and the extent of reduction was dependent on wood species and thermal modification method. Thermally modified aspen was stable during cycling climate tests, whereas pine showed considerable cracking when modified under superheated steam conditions (Thermo D). At lower modification temperature (180 oC) an increase in mass after modification in rapeseed oil of spruce, aspen and sapwood as well as heartwood of pine was observed, whereas at high temperature (240 oC) a mass loss could be found. Oil absorption in room tempered oil after thermal modification in oil was high for the more permeable aspen and pine (sapwood).


2000 ◽  
Vol 30 (1) ◽  
pp. 122-135 ◽  
Author(s):  
Björn Berg

Nitrogen fertilization increased concentrations of N, P, S, and K in Scots pine (Pinus sylvestris L.) needle litter, and in those of N, S, and Ca in Norway spruce (Picea abies (L.) Karst.). Lignin concentrations increased for both species. Initial rates and limit values for decomposition were estimated using a simple equation. For Scots pine litter, initial rates ranged between 0.0618 and 0.2986%/day with P, K, N, and Mg being positively related, but lignin and Ca negatively related. For Norway spruce, initial rates were low (0.0455-0.1007%/day) and positively related with initial concentrations of water solubles, K, and P but negatively with N, Ca, and lignin. Limit values for Scots pine litter ranged from 53.1 to 94.3% decomposition in fertilized plots and from 71.5 to 93.2% in controls. They were negatively related to N concentrations and positively to Mn and Ca. Limit values for Norway spruce litter ranged from 53.8 to 74.3% in controls and from 48 to 71.3% in fertilized plots and were positively correlated to Mn and Ca but not to N. The paper concludes that N fertilization will increase the fraction of Scots pine litter that accumulates as humus but not for Norway spruce.


Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 943
Author(s):  
Katri Nissinen ◽  
Virpi Virjamo ◽  
Antti Kilpeläinen ◽  
Veli-Pekka Ikonen ◽  
Laura Pikkarainen ◽  
...  

We studied the growth responses of boreal Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L. Karst.) and silver birch (Betula pendula Roth) seedlings to simulated climate warming of an average of 1.3 °C over the growing season in a controlled field experiment in central Finland. We had six replicate plots for elevated and ambient temperature for each tree species. The warming treatment lasted for the conifers for three growing seasons and for the birch two growing seasons. We measured the height and diameter growth of all the seedlings weekly during the growing season. The shoot and root biomass and their ratios were measured annually in one-third of seedlings harvested from each plot in autumn. After two growing seasons, the height, diameter and shoot biomass were 45%, 19% and 41% larger in silver birch seedlings under the warming treatment, but the root biomass was clearly less affected. After three growing seasons, the height, diameter, shoot and root biomass were under a warming treatment 39, 47, 189 and 113% greater in Scots pine, but the root:shoot ratio 29% lower, respectively. The corresponding responses of Norway spruce to warming were clearly smaller (e.g., shoot biomass 46% higher under a warming treatment). As a comparison, the relative response of height growth in silver birch was after two growing seasons equal to that measured in Scots pine after three growing seasons. Based on our findings, especially silver birch seedlings, but also Scots pine seedlings benefitted from warming, which should be taken into account in forest regeneration in the future.


2021 ◽  
pp. 073112142110286
Author(s):  
Alexander B. Kinney ◽  
Nicholas J. Rowland

This is an article that draws on the institutional work literature about provisional institutions. To date, nearly every U.S. sector has been impacted by COVID-19. To sustain their core missions, highly institutionalized organizations such as universities have had to rethink foundational structures and policies. Using a historical ethnographic approach to investigate records from faculty senate deliberations at “Rural State University” (RSU), the authors examine the implementation of a temporary grading policy to supplement traditional, qualitative grades spring 2020 during the outbreak. The authors find that RSU implemented a temporary, supplemental grading policy as a provisional institution to momentarily supersede traditional grading as a means to—as soon as possible—return to it. This finding contrasts with the common understanding that provisional institutions operate primarily as a temporary solution to a social problem that leads to more stable and enduring, ostensibly nonprovisional institutions. The temporary grading policy, the authors argue, constitutes a “late-stage” provisional institution and, with this new lens, subsequently characterize the more commonplace understanding of provisional institutions as “early-stage.” This contribution has theoretical implications for studies of institutions and empirical implications for research on shared governance and disruption in higher education.


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