| 1. |
- Berg, Björn, et al.
(författare)
-
Decomposition rates in late stages of Scots pine and Norway spruce needle litter: Influence of nutrients and substrate properties over a climate gradient
- 2022
-
Ingår i: Forest Ecology and Management. - : Elsevier. - 0378-1127 .- 1872-7042. ; 522
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this paper is to show different patterns for decomposition of the main mass of needle litter from two boreal and temperate coniferous tree species, both leading to a stabilized fraction of litter. To this purpose we have reviewed information on decomposition patterns in the lignin-dominated (late) stages of two local foliar litter types, namely those of Scots pine (Pinus silvestris) and Norway spruce (Picea abies) from two climatic gradients of equal extension. We have also reviewed factors determining the limit values for both species.Long-term decomposition studies were used to calculate annual mass loss in the lignin-dominated decomposition stage and relate these to mean annual temperature (MAT), mean annual precipitation (MAP) and concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn) and acid unhydrolyzable residue (gravimetric lignin, AUR).There was no effect of MAT on decomposition of either needle litter type. MAP had a rate-dampening effect on decomposition of Norway spruce litter. There was a rate-stimulating effect of Mn for Norway spruce litter but not for that of Scots pine. In spite of the strong negative effect of AUR and N on decomposition of Scots pine litter there was none at all for that of Norway spruce.Limit values for decomposition were related to the litters’ initial concentrations of N, Mn and AUR and differed between litter types for locally collected, natural litter and for that from experimental litter, the latter having higher N and lower Mn concentrations than the natural litter.We conclude that the two litter types have clear differences as regards rate- regulating factors for decomposition in the late lignin-dominated stage as well as for the stable fraction and suggest two different pathways for their decomposition. This is the first time that different pathways have been suggested for decomposing litter.
|
|
| 2. |
- Berg, Björn, 1943-, et al.
(författare)
-
Magnesium dynamics in decomposing foliar litter - a synthesis
- 2021
-
Ingår i: Geoderma. - : Elsevier. - 0016-7061 .- 1872-6259. ; 382
-
Tidskriftsartikel (refereegranskat)abstract
- We synthesized available data for magnesium (Mg) dynamics in newly shed and decomposing foliar litter of mainly pine (Pinus) species, Norway spruce (Picea abies), and birch (Betula) species. Using original, measured data from 40 stands organized in climatic gradients we intended to determine patterns of Mg concentration and net release vs accumulated mass loss of the litter. This synthesis is likely the first synthesis of Mg dynamics in decomposing litter.In paired stands, litter of both Norway spruce and lodgepole pine (Pinus contorta) had higher Mg concentrations than Scots pine (Pinus silvestris), with concentrations in Norway spruce litter even twice as high.In decomposing litter, Mg concentrations followed a quadratic (X2-X) function vs accumulated mass loss and consequently had minima, different for Norway spruce and Scots pine litter. Out of 68 decomposition studies 53 gave minimum concentration. The Mg minimum concentration during decomposition was positively related to initial Mg concentration for Scots pine and Scots pine plus lodgepole pine but not for Norway spruce. The increase in concentration suggests that after the minimum Mg was temporarily limiting.For Norway spruce litter there was a relationship between minimum concentration of Mg and the limit value. There was no such relationship for Scots pine and not for the combined pine data.Magnesium net release started directly after the incubation and was linear to accumulated mass loss of litter, giving a slope coefficient (release rate) for each study. The net release rate was linear to initial Mg concentration and all studies combined gave a negative linear relationship.
|
|
| 3. |
- Bommarco, Riccardo, et al.
(författare)
-
Genetic and phenotypic differences between thistle populations in response to habitat and weed management practices
- 2010
-
Ingår i: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066 .- 1095-8312. ; 99:4, s. 797-807
-
Tidskriftsartikel (refereegranskat)abstract
- Rapid evolutionary change is increasingly being recognized as commonplace, but the evolutionary consequences for species and ecosystems under human-induced selection regimes have not been explored in detail, although many species occur in such environments. In a common garden experiment and with amplified fragment length polymorphism markers, we examined whether genetic differentiation has taken place between spatially intermixed populations of creeping thistles Cirsium arvense (Asteraceae) collected from a natural habitat (maritime shores), a semi-natural habitat (road verges) and arable fields under two management regimes: conventional and organic farming. Populations of C. arvense have altered genetically and locally adapted their growth patterns with changed land use. Although plants from different habitats showed similar total biomass production, shoot and root production was higher for maritime populations, suggesting selection for increased competitive ability. Competitive ability then declined in the order semi-natural, conventional farms and organic farms. Thistles in arable fields may be more selected for tolerance against disturbances from herbicides and mechanical weed control. In addition, early shoot sprouting and genetic analysis showed differentiation between plants originating from conventional farms and farms that were converted to organic 9–30 years ago, suggesting some adaptation to altered crop cultivation practices
|
|
| 4. |
- Eriksson, Sofia, et al.
(författare)
-
Historical perspepctives on landscape representation and forest composition in Woodland Key Habitats compared to formally protected forest in boreal Sweden
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Habitats of Swedish conservation interests are in general small and fragmented following the extensive and intensive forest management history. This study covering 71 000 ha of boreal Sweden investigates how history influences present-day distribution and composition of forests identified as high conservation value habitats and how they are protected. We also investigated if the habitat criteria used to describe reservations differed between reservation types and if habitat criteria were associated with the size of Woodland Key Habitats. The results show strong effects from historical ownership and historical forest type on the probability of an area being set aside as formally protected or as voluntary protected Woodland Key Habitats. We also found that both formal reservations and Woodland Key Habitats primarily cover coniferous forest in the age interval 70-110 years but not the presumably most valuable oldest coniferous category >110 or deciduous forests, which are as common in reservations as in other areas. Old deciduous forests (>110 years) are significantly more rare in formal reservations compared to the forest matrix. When viewed in a context of fragmentation and edge effects the results underline the importance of evaluating reserved areas and Woodland Key Habitats in a wider temporal and larger spatial perspective to optimize conservation management efforts. Maximal representation and biodiversity can be better achieved if new reservations are chosen to represent different ownership and forest history, and if they are selected in a landscape context related to present reservations and the present surrounding production forest.
|
|
| 5. |
- Eriksson, Sofia, et al.
(författare)
-
Historical perspepctives on landscape representation and forest composition in Woodland Key Habitats compared to formally protected forest in boreal Sweden
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Habitats of Swedish conservation interests are in general small and fragmented following the extensive and intensive forest management history. This study covering 71 000 ha of boreal Sweden investigates how history influences present-day distribution and composition of forests identified as high conservation value habitats and how they are protected. We also investigated if the habitat criteria used to describe reservations differed between reservation types and if habitat criteria were associated with the size of Woodland Key Habitats. The results show strong effects from historical ownership and historical forest type on the probability of an area being set aside as formally protected or as voluntary protected Woodland Key Habitats. We also found that both formal reservations and Woodland Key Habitats primarily cover coniferous forest in the age interval 70-110 years but not the presumably most valuable oldest coniferous category >110 or deciduous forests, which are as common in reservations as in other areas. Old deciduous forests (>110 years) are significantly more rare in formal reservations compared to the forest matrix. When viewed in a context of fragmentation and edge effects the results underline the importance of evaluating reserved areas and Woodland Key Habitats in a wider temporal and larger spatial perspective to optimize conservation management efforts. Maximal representation and biodiversity can be better achieved if new reservations are chosen to represent different ownership and forest history, and if they are selected in a landscape context related to present reservations and the present surrounding production forest.
|
|
| 6. |
- Eriksson, Sofia, et al.
(författare)
-
Historical perspepctives on landscape representation and forest composition in Woodland Key Habitats compared to formally protected forest in boreal Sweden
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Habitats of Swedish conservation interests are in general small and fragmented following the extensive and intensive forest management history. This study covering 71 000 ha of boreal Sweden investigates how history influences present-day distribution and composition of forests identified as high conservation value habitats and how they are protected. We also investigated if the habitat criteria used to describe reservations differed between reservation types and if habitat criteria were associated with the size of Woodland Key Habitats. The results show strong effects from historical ownership and historical forest type on the probability of an area being set aside as formally protected or as voluntary protected Woodland Key Habitats. We also found that both formal reservations and Woodland Key Habitats primarily cover coniferous forest in the age interval 70-110 years but not the presumably most valuable oldest coniferous category >110 or deciduous forests, which are as common in reservations as in other areas. Old deciduous forests (>110 years) are significantly more rare in formal reservations compared to the forest matrix. When viewed in a context of fragmentation and edge effects the results underline the importance of evaluating reserved areas and Woodland Key Habitats in a wider temporal and larger spatial perspective to optimize conservation management efforts. Maximal representation and biodiversity can be better achieved if new reservations are chosen to represent different ownership and forest history, and if they are selected in a landscape context related to present reservations and the present surrounding production forest.
|
|
| 7. |
- Eriksson, Sofia, et al.
(författare)
-
Interactions between historical forest composition and ownership affect present composition of older forest in boreal Sweden
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this study we reconstruct forest composition during the 1860s for a 71000 ha area in southern boreal Sweden. The aim is to show how historical ownership and associated anthropogenic disturbances act as a source of heterogeneity in the present-day distribution and composition of coniferous and deciduous forest within the commercial production forest. We use older (>110 years) and mature (70-110 years) forest as response variables in generalized linear models with a binominal error distribution. The explanatory variables include size of zone, historical type of ownership zone (village, company, and farm), amount of forest, and forest type. We focus in particular on investigating effects from interacting explanatory variables. The significant statistical associations in the study indicate that patterns of deciduous and coniferous older patches differ, and that deciduous patches differ in relation to age interval. The oldest deciduous patches, for example, are today more likely on areas that had deciduous cover also in the past and stood on forestland managed by farmers, but less likely on the same habitat managed by companies. We show that there are strong effects on present forest composition from historical ownership and forest composition. We argue that by including local data on past ownership combined with knowledge on use patterns management could be better adapted to local landscape dynamics compared to the application of overly generalized patterns or models of boreal dynamics that excludes interactions with management.
|
|
| 8. |
- Eriksson, Sofia, et al.
(författare)
-
Interactions between historical forest composition and ownership affect present composition of older forest in boreal Sweden
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this study we reconstruct forest composition during the 1860s for a 71000 ha area in southern boreal Sweden. The aim is to show how historical ownership and associated anthropogenic disturbances act as a source of heterogeneity in the present-day distribution and composition of coniferous and deciduous forest within the commercial production forest. We use older (>110 years) and mature (70-110 years) forest as response variables in generalized linear models with a binominal error distribution. The explanatory variables include size of zone, historical type of ownership zone (village, company, and farm), amount of forest, and forest type. We focus in particular on investigating effects from interacting explanatory variables. The significant statistical associations in the study indicate that patterns of deciduous and coniferous older patches differ, and that deciduous patches differ in relation to age interval. The oldest deciduous patches, for example, are today more likely on areas that had deciduous cover also in the past and stood on forestland managed by farmers, but less likely on the same habitat managed by companies. We show that there are strong effects on present forest composition from historical ownership and forest composition. We argue that by including local data on past ownership combined with knowledge on use patterns management could be better adapted to local landscape dynamics compared to the application of overly generalized patterns or models of boreal dynamics that excludes interactions with management.
|
|
| 9. |
- Eriksson, Sofia, et al.
(författare)
-
Interactions between historical forest composition and ownership affect present composition of older forest in boreal Sweden
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this study we reconstruct forest composition during the 1860s for a 71000 ha area in southern boreal Sweden. The aim is to show how historical ownership and associated anthropogenic disturbances act as a source of heterogeneity in the present-day distribution and composition of coniferous and deciduous forest within the commercial production forest. We use older (>110 years) and mature (70-110 years) forest as response variables in generalized linear models with a binominal error distribution. The explanatory variables include size of zone, historical type of ownership zone (village, company, and farm), amount of forest, and forest type. We focus in particular on investigating effects from interacting explanatory variables. The significant statistical associations in the study indicate that patterns of deciduous and coniferous older patches differ, and that deciduous patches differ in relation to age interval. The oldest deciduous patches, for example, are today more likely on areas that had deciduous cover also in the past and stood on forestland managed by farmers, but less likely on the same habitat managed by companies. We show that there are strong effects on present forest composition from historical ownership and forest composition. We argue that by including local data on past ownership combined with knowledge on use patterns management could be better adapted to local landscape dynamics compared to the application of overly generalized patterns or models of boreal dynamics that excludes interactions with management.
|
|
