Canadian boreal mixedwood forests are extensive,with large potential for carbon sequestration and storage;thus,knowledge of their carbon stocks at different stand ages is needed to adapt forest management practices to...Canadian boreal mixedwood forests are extensive,with large potential for carbon sequestration and storage;thus,knowledge of their carbon stocks at different stand ages is needed to adapt forest management practices to help meet climate-change mitigation goals.Carbon stocks were quantified at three Ontario boreal mixedwood sites.A harvested stand,a juvenile stand replanted with spruce seedlings and a mature stand had total carbon stocks(±SE)of 133±13 at age 2,130±13 at age 25,and 207±15 Mg C ha^-1 at age 81 years.At the clear-cut site,stocks were reduced by about 40%or 90 Mg C ha^-1 at harvest.Vegetation held 27,34 and 62%of stocks,while detritus held 34,29 and 13%of stocks at age 2,25 and 81,respectively.Mineral soil carbon stocks averaged 51 Mg C ha^-1,and held 38,37 and 25%of stocks.Aboveground net primary productivity(±SE)in the harvested and juvenile stand was 2.1±0.2 and 3.7±0.3 Mg C ha^-1 per annum(p.a.),compared to 2.6±2.5 Mg C ha^-1 p.a.in the mature stand.The mature canopies studied had typical boreal mixedwood composition and mean carbon densities of 208 Mg C ha^-1,which is above average for managed Canadian boreal forest ecosystems.A comparison of published results from Canadian boreal forest ecosystems showed that carbon stocks in mixedwood stands are typically higher than coniferous stands at all ages,which was also true for stocks in vegetation and detritus.Also,aboveground net primary productivity was typically found to be higher in mixedwood than in coniferous boreal forest stands over a range of ages.Measurements from this study,together with those published from the other boreal forest stands demonstrate the potential for enhanced carbon sequestration through modified forest management practices to take advantage of Canadian boreal mixedwood stand characteristics.展开更多
This work studied the effects of tree species composition on soil carbon storage in five mixed stands dominated by oriental beech and grown in the western Caspian region in Guilan province, called Astara, Asalem, Fuma...This work studied the effects of tree species composition on soil carbon storage in five mixed stands dominated by oriental beech and grown in the western Caspian region in Guilan province, called Astara, Asalem, Fuman, Chere and Shenrud. The thickness of the litter layer, soil characteristics, tree composition and percentage of canopy coverage were measured in each stand. Total soil organic carbon differed significantly by stand. Total （organic） carbon stores at Fuman, which had the lowest tree species richness with 2 species and least canopy coverage （75%）, were significantly （p〈0.05） higher than at other locations. Carbon stor-age in topsoil （0-10 cm） was significantly lower in Shenrud, which had the highest tree species richness with 5 species and highest canopy cov-erage （95%）. The high percentage of canopy coverage in Shenrud proba-bly limited the conversion of litter to humus. However, in the second soil layer （10-25 cm）, Asalem, with high tree species richness and canopy coverage, had the highest carbon storage. This can be explained by the different rooting patterns of different tree species. In the Hyrcanian forest. According to the results, it can be concluded that not only tree composi-tion but also canopy coverage percentage should be taken under consid-eration to manage soil carbon retention and release.展开更多
The structure and species composition of undisturbed natural forests serve as benchmarks for understanding forest carbon storage potential for reduced carbon emissions. Even though Kenya is seeking to stabilize forest...The structure and species composition of undisturbed natural forests serve as benchmarks for understanding forest carbon storage potential for reduced carbon emissions. Even though Kenya is seeking to stabilize forest cover, reverse degradation and increase forest cover through mechanisms such as REDD+, there is relatively little information on inherent forest carbon storage potential or its response to disturbance. Comparative studies were undertaken in three remnant fragments of indigenous forests in Taita Hills, Kenya to characterize the structure and forest carbon storage potential of undisturbed, moderately and heavily disturbed sites within these forests. The sensitivity of forest carbon storage estimates to different methods of tree biomass estimation were also examined, including estimates which used DBH, tree height and wood density from extracted tree cores. Disturbance altered the forest structure, reduced species diversity and decreased the capacity of the forests to sequester carbon. The forests’ capacity to sequester carbon reduced by between 9.2% and 70.7% depending on the site (forest fragment) and level of disturbance. Models with DBH and wood density gave higher quantities of carbon of between 0.9% and 44.4% for sites exhibiting different levels of disturbance. The present results suggest that disturbance had strong influence on forest structure, species diversity and carbon stocks and therefore maintaining the forests’ ecological integrity over the long-term may prove difficult if the frequency and intensity of disturbance increases. Moreover, development and implementation of effective mitigation strategies to reduce carbon emissions will require the use of local biomass models since they are accurate.展开更多
Although it has been recognized that soils play a critical role in carbon storage and that coastal temperate forests have considerable potential to sequester soil organic carbon (SOC), studies related to SOC stocks an...Although it has been recognized that soils play a critical role in carbon storage and that coastal temperate forests have considerable potential to sequester soil organic carbon (SOC), studies related to SOC stocks and stability are scarce in these ecosystems. Forest disturbances may leave legacies on SOC properties and may further compromise SOC storage capacity of these ecosystems. In the Pacific Spirit Regional Park of southwestern British Columbia, we compared SOC stocks and stability among three second-growth forests that have been affected by disturbances of different magnitudes. We collected data on soil chemical and physical properties to estimate SOC content and assess SOC stability. We found that SOC stocks in the forest characterized by low magnitude disturbance were greater than those of the forest characterized by high magnitude disturbance (8.2 ± 1.3 kg·Cm<sup>-2</sup> versus 5.3 ± 0.1 kg·Cm<sup>-2</sup> to 30 cm depth). SOC was less stable in the highly disturbed forest and subsequent vegetation changes might have further reduced SOC stability. Our results provide insight into the role of disturbance history in the current SOC storage capacity of coastal temperate rainforests of British Columbia.展开更多
The present study estimates carbon stocks (C-stocks) of the Oak scrub forest of Sheringal valley through field inventory. Stem density (haǃ), tree height (m), basal area (m2·haǃ), stem volume (...The present study estimates carbon stocks (C-stocks) of the Oak scrub forest of Sheringal valley through field inventory. Stem density (haǃ), tree height (m), basal area (m2·haǃ), stem volume (m2·haǃ), stem biomass (t·haǃ), total biomass (t·haǃ), and total C-stock (t·haǃ), were calculated. Stem density varied between 80±8.16 to 510 ± 42 trees haǃ, with a mean value of 226 ± 7 tress haǃ. The average tree height, basal area and stem volume were 5.47 ± 0.76 m, 12.82 ± 0.25 m2·haǃ and 46.37 ± 0.85 m3·haǃ respectively. The total calculated stem biomass was 32.46 ± 0.60 t·haǃ and total tree biomass was 51.61 ± 0.60 t·haǃ. The calculated C-stocks in the Oak scrub forest ranged from 2.005 ± 1.32 t·haǃ to 63.1 ± 3.34 t·haǃ and the mean C stocks was 25.80 ± 0.47 t·haǃ. The results of the study confirmed that the Oak scrub forest acts as a valuable sink of carbon, but this valuable storage factory of carbon faced the problems of excess uses for fuel wood, forage, domestic uses (mostly for construction) and unscientific management. Proper scientific management and proper utilization of the forest can be significant measures to enhance the potential of the forest to stored and sink more carbon and can be included for CDM and REED++ under Keyto protocol.展开更多
基金provided by the Canadian Forest Service,with in-kind support from the Ontario Ministry of Natural Resources and Forestry
文摘Canadian boreal mixedwood forests are extensive,with large potential for carbon sequestration and storage;thus,knowledge of their carbon stocks at different stand ages is needed to adapt forest management practices to help meet climate-change mitigation goals.Carbon stocks were quantified at three Ontario boreal mixedwood sites.A harvested stand,a juvenile stand replanted with spruce seedlings and a mature stand had total carbon stocks(±SE)of 133±13 at age 2,130±13 at age 25,and 207±15 Mg C ha^-1 at age 81 years.At the clear-cut site,stocks were reduced by about 40%or 90 Mg C ha^-1 at harvest.Vegetation held 27,34 and 62%of stocks,while detritus held 34,29 and 13%of stocks at age 2,25 and 81,respectively.Mineral soil carbon stocks averaged 51 Mg C ha^-1,and held 38,37 and 25%of stocks.Aboveground net primary productivity(±SE)in the harvested and juvenile stand was 2.1±0.2 and 3.7±0.3 Mg C ha^-1 per annum(p.a.),compared to 2.6±2.5 Mg C ha^-1 p.a.in the mature stand.The mature canopies studied had typical boreal mixedwood composition and mean carbon densities of 208 Mg C ha^-1,which is above average for managed Canadian boreal forest ecosystems.A comparison of published results from Canadian boreal forest ecosystems showed that carbon stocks in mixedwood stands are typically higher than coniferous stands at all ages,which was also true for stocks in vegetation and detritus.Also,aboveground net primary productivity was typically found to be higher in mixedwood than in coniferous boreal forest stands over a range of ages.Measurements from this study,together with those published from the other boreal forest stands demonstrate the potential for enhanced carbon sequestration through modified forest management practices to take advantage of Canadian boreal mixedwood stand characteristics.
文摘This work studied the effects of tree species composition on soil carbon storage in five mixed stands dominated by oriental beech and grown in the western Caspian region in Guilan province, called Astara, Asalem, Fuman, Chere and Shenrud. The thickness of the litter layer, soil characteristics, tree composition and percentage of canopy coverage were measured in each stand. Total soil organic carbon differed significantly by stand. Total （organic） carbon stores at Fuman, which had the lowest tree species richness with 2 species and least canopy coverage （75%）, were significantly （p〈0.05） higher than at other locations. Carbon stor-age in topsoil （0-10 cm） was significantly lower in Shenrud, which had the highest tree species richness with 5 species and highest canopy cov-erage （95%）. The high percentage of canopy coverage in Shenrud proba-bly limited the conversion of litter to humus. However, in the second soil layer （10-25 cm）, Asalem, with high tree species richness and canopy coverage, had the highest carbon storage. This can be explained by the different rooting patterns of different tree species. In the Hyrcanian forest. According to the results, it can be concluded that not only tree composi-tion but also canopy coverage percentage should be taken under consid-eration to manage soil carbon retention and release.
文摘The structure and species composition of undisturbed natural forests serve as benchmarks for understanding forest carbon storage potential for reduced carbon emissions. Even though Kenya is seeking to stabilize forest cover, reverse degradation and increase forest cover through mechanisms such as REDD+, there is relatively little information on inherent forest carbon storage potential or its response to disturbance. Comparative studies were undertaken in three remnant fragments of indigenous forests in Taita Hills, Kenya to characterize the structure and forest carbon storage potential of undisturbed, moderately and heavily disturbed sites within these forests. The sensitivity of forest carbon storage estimates to different methods of tree biomass estimation were also examined, including estimates which used DBH, tree height and wood density from extracted tree cores. Disturbance altered the forest structure, reduced species diversity and decreased the capacity of the forests to sequester carbon. The forests’ capacity to sequester carbon reduced by between 9.2% and 70.7% depending on the site (forest fragment) and level of disturbance. Models with DBH and wood density gave higher quantities of carbon of between 0.9% and 44.4% for sites exhibiting different levels of disturbance. The present results suggest that disturbance had strong influence on forest structure, species diversity and carbon stocks and therefore maintaining the forests’ ecological integrity over the long-term may prove difficult if the frequency and intensity of disturbance increases. Moreover, development and implementation of effective mitigation strategies to reduce carbon emissions will require the use of local biomass models since they are accurate.
文摘Although it has been recognized that soils play a critical role in carbon storage and that coastal temperate forests have considerable potential to sequester soil organic carbon (SOC), studies related to SOC stocks and stability are scarce in these ecosystems. Forest disturbances may leave legacies on SOC properties and may further compromise SOC storage capacity of these ecosystems. In the Pacific Spirit Regional Park of southwestern British Columbia, we compared SOC stocks and stability among three second-growth forests that have been affected by disturbances of different magnitudes. We collected data on soil chemical and physical properties to estimate SOC content and assess SOC stability. We found that SOC stocks in the forest characterized by low magnitude disturbance were greater than those of the forest characterized by high magnitude disturbance (8.2 ± 1.3 kg·Cm<sup>-2</sup> versus 5.3 ± 0.1 kg·Cm<sup>-2</sup> to 30 cm depth). SOC was less stable in the highly disturbed forest and subsequent vegetation changes might have further reduced SOC stability. Our results provide insight into the role of disturbance history in the current SOC storage capacity of coastal temperate rainforests of British Columbia.
文摘The present study estimates carbon stocks (C-stocks) of the Oak scrub forest of Sheringal valley through field inventory. Stem density (haǃ), tree height (m), basal area (m2·haǃ), stem volume (m2·haǃ), stem biomass (t·haǃ), total biomass (t·haǃ), and total C-stock (t·haǃ), were calculated. Stem density varied between 80±8.16 to 510 ± 42 trees haǃ, with a mean value of 226 ± 7 tress haǃ. The average tree height, basal area and stem volume were 5.47 ± 0.76 m, 12.82 ± 0.25 m2·haǃ and 46.37 ± 0.85 m3·haǃ respectively. The total calculated stem biomass was 32.46 ± 0.60 t·haǃ and total tree biomass was 51.61 ± 0.60 t·haǃ. The calculated C-stocks in the Oak scrub forest ranged from 2.005 ± 1.32 t·haǃ to 63.1 ± 3.34 t·haǃ and the mean C stocks was 25.80 ± 0.47 t·haǃ. The results of the study confirmed that the Oak scrub forest acts as a valuable sink of carbon, but this valuable storage factory of carbon faced the problems of excess uses for fuel wood, forage, domestic uses (mostly for construction) and unscientific management. Proper scientific management and proper utilization of the forest can be significant measures to enhance the potential of the forest to stored and sink more carbon and can be included for CDM and REED++ under Keyto protocol.
