In Hebei Province of North China, forest was recovered with natural recruitment in plantations with large area of clear-cutting Chinese pine（Pinus tabuliformis）. This study was aimed to demonstrate the dynamic chara...In Hebei Province of North China, forest was recovered with natural recruitment in plantations with large area of clear-cutting Chinese pine（Pinus tabuliformis）. This study was aimed to demonstrate the dynamic characteristics of recruits during the natural recruitment. Both plot survey and the spatial point-pattern analysis were performed. Five developmental stages of natural recruitment were selected and studied, including 1 year before and 2, 5, 8, and 11 years after clear-cutting. Different slope aspects were also included. Natural recruitment was always dominated by Chinese pine with a proportion of higher than 90%. For plots of 1 year before clear-cutting on east-and north-facing slopes, recruit densities were 7886 and 5036 stems/hm2, the average heights were 0.78（±0.85） and 1.06（±1.15） m, and the average diameters at breast height（DBH） were 3.21（±1.38） and 2.91（±1.38） cm, respectively. After clear-cutting, recruit density was initially increased, then it was gradually declined with time; however, the variation of average DBH was contrary to that of recruit density. Both of them were no longer varied between 8 and 11 years after clear-cutting. The average height of recruits continued to increase after clear-cutting. For the plots of 11 years after clear-cutting on east-and north-facing slopes, average heights of recruits reached 2.00（±1.14） and 2.24（±1.20） m, respectively. The statuses of recruits on north-facing slopes were better than those on east-facing slopes after clear-cutting. Meanwhile, recruits on east-facing slopes were always aggregated at small scales, while spatial pattern of recruits varied with time on north-facing slopes. Moreover, forest was recovered more quickly by natural recruitment than by artificial afforestation after clear-cutting. The structural diversity was higher in naturally regenerated forests than in plantations of the same age. Our results demonstrated that clear-cutting of Chinese pine plantations recovered by natural recruitment has the potential to be an effective approach for establishing multifunctional forest.展开更多
[Objective] This study aims to analyze the natural regeneration characteristics and growth factors of two cut-over lands of Larix gmelini forests in Greater Khingan Mountains. [Method] A database was established based...[Objective] This study aims to analyze the natural regeneration characteristics and growth factors of two cut-over lands of Larix gmelini forests in Greater Khingan Mountains. [Method] A database was established based on the information of natural regeneration cut-over sample plots of Larix gmelini forests in Greater Khingan Mountains. Natural regeneration characteristics of clear-cutting sample plot and shelterwood-cutting sample plot of Larix gmelini in the northern regions of Greater Khingan Mountains were investigated by programming analysis. [Result] The natural regeneration of two principal felling systems was both good, and that of shelterwood-cutting sample plot was better. There were significant linear regression relationships among various growth factors of naturally regenerated plants. [Conclusion] This study provided scientific theoretical guidance for subsequent deforestation and regeneration in Greater Khingan Mountains.展开更多
Aims Clear-cutting is a common forest management practice,especially in subtropical China.However,the potential ecological consequences of clear-cutting remain unclear.In particular,the effect of clear-cutting on soil...Aims Clear-cutting is a common forest management practice,especially in subtropical China.However,the potential ecological consequences of clear-cutting remain unclear.In particular,the effect of clear-cutting on soil processes,such as the carbon cycle,has not been quantified in subtropical forests.Here,we investigated the response of soil respiration(Rs)to clear-cutting during a 12-month period in a subtropical forest in eastern China.Methods We randomly selected four clear-cut(CC)plots and four corresponding undisturbed forest(UF)plots.Measurements of Rs were made at monthly time points and were combined with continuous climatic measurements in both CC and UF.Daily Rs was estimated by interpolating data with an exponential model dependent on soil temperature.Daily Rs was cumulated to annual Rs estimates.Important Findings In the first year after clear-cutting,annual estimates of Rs in CC(508±23g C m^(−2) yr^(−1))showed no significant difference to UF plots(480±12g C m^(−2) yr^(−1)).During the summer,soil temperatures were usually higher,whereas the soil volumetric water content was lower in CC than in UF plots.The long-term effects of clear-cutting on Rs are not significant,although there might be effects during the first several months after clear-cutting.Compared with previous work,this pattern was more pronounced in our subtropical forest than in the temperate and boreal forests that have been studied by others.With aboveground residuals off-site after clear-cutting,our results indicate that the stimulation of increasing root debris,as well as environmental changes,will not lead to a significant increase in Rs.In addition,long-term Rs will not show a significant decrease from the termination of root respiration,and this observation might be because of the influence of fast-growing vegetation after clear-cutting in situ.展开更多
Soil CO2 efflux,the second largest flux in a forest carbon budget,plays an important role in global carbon cycling.Forest logging is expected to have large effects on soil CO2 efflux and carbon sequestration in forest...Soil CO2 efflux,the second largest flux in a forest carbon budget,plays an important role in global carbon cycling.Forest logging is expected to have large effects on soil CO2 efflux and carbon sequestration in forest ecosystems.However,a comprehensive understanding of soil CO2 efflux dynamics in response to forest logging remains elusive due to large variability in results obtained across individual studies.Here,we used a meta-analysis approach to synthesize the results of 77 individual field studies to determine the impacts of forest logging on soil CO2 efflux.Our results reveal that forest logging significantly stimulated soil CO2 efflux of the growing season by 5.02%.However,averaged across all studies,nonsignificant effect was detected following forest logging.The large variation among forest logging impacts was best explained by forest type,logging type,and time since logging.Soil CO2 efflux in coniferous forests exhibited a significant increase(4.38%)due to forest logging,while mixed and hardwood forests showed no significant change.Logging type also had a significant effect on soil CO2 efflux,with thinning increasing soil CO2 efflux by 12.05%,while clear-cutting decreasing soil CO2 efflux by 8.63%.The time since logging also had variable effects,with higher soil CO2 efflux for 2 years after logging,and lower for 3-6 years after logging;when exceeded 6 years,soil CO2 efflux increased.As significantly negative impacts of forest logging were detected on fine root biomass,the general positive effects on soil CO2 efflux can be explained by the accelerated decomposition of organic matter as a result of elevated soil temperature and organic substrate quality.Our results demonstrate that forest logging had potentially negative effects on carbon sequestration in forest ecosystems.展开更多
Forest management such as timber harvesting shapes fire regimes and landscape patterns, and these patterns often differ significantly from those under natural disturbances. Our objective was to examine the effects of ...Forest management such as timber harvesting shapes fire regimes and landscape patterns, and these patterns often differ significantly from those under natural disturbances. Our objective was to examine the effects of timber harvesting modes on fire regimes and landscape patterns in a boreal forest of Northeast China. We used a spatially explicit landscape model, LANDIS, to simulate the changes of forest landscape in the Huzhong forest region of the Great Khingan Mountains under no-cutting, clear-cutting, gradual-cutting and selective-cutting modes. Results showed that：（1） the fine fuel loadings generally decreased while the coarse fuel loadings increased with the increase of timber harvesting intensity;（2） the potential burn area significantly varied among different cutting modes, but the potential fire frequency had no obvious difference. Moreover, timber harvesting generally increased the potential fire risk;（3） clear-cutting mode significantly decreased the mean patch size and the aggregation of larch forests and increased the mean patch size and the aggregation of white birch forests. Therefore, clear-cutting mode should be abandoned, and selective-cutting mode be recommended for the sustainable forest management in the Great Khingan Mountains.展开更多
The study aimed to assess the response of ep- and hemiedaphic Collembola communities(activity, richness, community structure) to a disturbance, the subsequent management regime and to the season(summer, winter) in a H...The study aimed to assess the response of ep- and hemiedaphic Collembola communities(activity, richness, community structure) to a disturbance, the subsequent management regime and to the season(summer, winter) in a High Tatra Mountains spruce forest destroyed by a windstorm.Fire and clear-cut resulted in an initial increase in the activity of Collembola inhabiting open areas,opportunistic or generalist species, while forest specialists diminished in numbers or disappeared.Our results indicated that treatment with nonextracted fallen trees(NEX) provided a better chance for forest species to survive compared with their survival in open habitats of extracted(EXT) and wildfire(FIR) treatments. Great species' potential of NEX treatment was indicated by Chao2 estimator and activity/species rarefaction curves. Communities of NEX treatment were more similar to the reference(REF) treatment, documented by ordination and cluster analyses. Thus, leaving fallen timber after a windthrow to natural process of succession is suitable for survival of forest species and maintenance of diversity in forests restoration than timber extraction.Community structure in wildfire(FIR) stands was the most dissimilar to the other treatments. Most of the species trapped in this treatment belonged to hemiedaphic life forms, while the activity of larger epedaphic species diminished. In contrast, the highest number of trapped Collembola in EXT treatment was connected with the larger-bodied epigeic species with fast dispersal ability. The trapping period affected both the number of individuals and species richness;Collembola activity and species diversity in the individual treatments were lower in winter compared with the summer period. Several species increased activity during the winter period, namely Folsomia penicula, Friesea mirabilis, F. truncata, Hypogastrura socialis and Protaphorura aurantiaca.展开更多
基金supported by the National Key R&D Program of China (2017YFD0600501)the Fundamental Research Funds for the Central Universities of China (TD2011-08)
文摘In Hebei Province of North China, forest was recovered with natural recruitment in plantations with large area of clear-cutting Chinese pine（Pinus tabuliformis）. This study was aimed to demonstrate the dynamic characteristics of recruits during the natural recruitment. Both plot survey and the spatial point-pattern analysis were performed. Five developmental stages of natural recruitment were selected and studied, including 1 year before and 2, 5, 8, and 11 years after clear-cutting. Different slope aspects were also included. Natural recruitment was always dominated by Chinese pine with a proportion of higher than 90%. For plots of 1 year before clear-cutting on east-and north-facing slopes, recruit densities were 7886 and 5036 stems/hm2, the average heights were 0.78（±0.85） and 1.06（±1.15） m, and the average diameters at breast height（DBH） were 3.21（±1.38） and 2.91（±1.38） cm, respectively. After clear-cutting, recruit density was initially increased, then it was gradually declined with time; however, the variation of average DBH was contrary to that of recruit density. Both of them were no longer varied between 8 and 11 years after clear-cutting. The average height of recruits continued to increase after clear-cutting. For the plots of 11 years after clear-cutting on east-and north-facing slopes, average heights of recruits reached 2.00（±1.14） and 2.24（±1.20） m, respectively. The statuses of recruits on north-facing slopes were better than those on east-facing slopes after clear-cutting. Meanwhile, recruits on east-facing slopes were always aggregated at small scales, while spatial pattern of recruits varied with time on north-facing slopes. Moreover, forest was recovered more quickly by natural recruitment than by artificial afforestation after clear-cutting. The structural diversity was higher in naturally regenerated forests than in plantations of the same age. Our results demonstrated that clear-cutting of Chinese pine plantations recovered by natural recruitment has the potential to be an effective approach for establishing multifunctional forest.
基金Supported by Forestry Industry Public Welfare Project of State Forestry Bureau of China(201204205)~~
文摘[Objective] This study aims to analyze the natural regeneration characteristics and growth factors of two cut-over lands of Larix gmelini forests in Greater Khingan Mountains. [Method] A database was established based on the information of natural regeneration cut-over sample plots of Larix gmelini forests in Greater Khingan Mountains. Natural regeneration characteristics of clear-cutting sample plot and shelterwood-cutting sample plot of Larix gmelini in the northern regions of Greater Khingan Mountains were investigated by programming analysis. [Result] The natural regeneration of two principal felling systems was both good, and that of shelterwood-cutting sample plot was better. There were significant linear regression relationships among various growth factors of naturally regenerated plants. [Conclusion] This study provided scientific theoretical guidance for subsequent deforestation and regeneration in Greater Khingan Mountains.
基金This study was supported by the EU 7th FP Project BACCARA(Contract No.226299)the MOST Sino-EU Cooperation Program(Contract No.Sino-EU 0916)the National Natural Science Foundation of China(Grant No.31025005 and 31021001).
文摘Aims Clear-cutting is a common forest management practice,especially in subtropical China.However,the potential ecological consequences of clear-cutting remain unclear.In particular,the effect of clear-cutting on soil processes,such as the carbon cycle,has not been quantified in subtropical forests.Here,we investigated the response of soil respiration(Rs)to clear-cutting during a 12-month period in a subtropical forest in eastern China.Methods We randomly selected four clear-cut(CC)plots and four corresponding undisturbed forest(UF)plots.Measurements of Rs were made at monthly time points and were combined with continuous climatic measurements in both CC and UF.Daily Rs was estimated by interpolating data with an exponential model dependent on soil temperature.Daily Rs was cumulated to annual Rs estimates.Important Findings In the first year after clear-cutting,annual estimates of Rs in CC(508±23g C m^(−2) yr^(−1))showed no significant difference to UF plots(480±12g C m^(−2) yr^(−1)).During the summer,soil temperatures were usually higher,whereas the soil volumetric water content was lower in CC than in UF plots.The long-term effects of clear-cutting on Rs are not significant,although there might be effects during the first several months after clear-cutting.Compared with previous work,this pattern was more pronounced in our subtropical forest than in the temperate and boreal forests that have been studied by others.With aboveground residuals off-site after clear-cutting,our results indicate that the stimulation of increasing root debris,as well as environmental changes,will not lead to a significant increase in Rs.In addition,long-term Rs will not show a significant decrease from the termination of root respiration,and this observation might be because of the influence of fast-growing vegetation after clear-cutting in situ.
基金the National Natural Science Foundation of China(4170129641801069)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23060301)the CAS"Light of West China"Program(29Y829861).
文摘Soil CO2 efflux,the second largest flux in a forest carbon budget,plays an important role in global carbon cycling.Forest logging is expected to have large effects on soil CO2 efflux and carbon sequestration in forest ecosystems.However,a comprehensive understanding of soil CO2 efflux dynamics in response to forest logging remains elusive due to large variability in results obtained across individual studies.Here,we used a meta-analysis approach to synthesize the results of 77 individual field studies to determine the impacts of forest logging on soil CO2 efflux.Our results reveal that forest logging significantly stimulated soil CO2 efflux of the growing season by 5.02%.However,averaged across all studies,nonsignificant effect was detected following forest logging.The large variation among forest logging impacts was best explained by forest type,logging type,and time since logging.Soil CO2 efflux in coniferous forests exhibited a significant increase(4.38%)due to forest logging,while mixed and hardwood forests showed no significant change.Logging type also had a significant effect on soil CO2 efflux,with thinning increasing soil CO2 efflux by 12.05%,while clear-cutting decreasing soil CO2 efflux by 8.63%.The time since logging also had variable effects,with higher soil CO2 efflux for 2 years after logging,and lower for 3-6 years after logging;when exceeded 6 years,soil CO2 efflux increased.As significantly negative impacts of forest logging were detected on fine root biomass,the general positive effects on soil CO2 efflux can be explained by the accelerated decomposition of organic matter as a result of elevated soil temperature and organic substrate quality.Our results demonstrate that forest logging had potentially negative effects on carbon sequestration in forest ecosystems.
基金supported by the National Natural Science Foundation of China (41201185, 31070422, 41271201)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA05050201)the Agricultural Science and Technology Research Projects Foundation of Shenyang (F13-146-3-00)
文摘Forest management such as timber harvesting shapes fire regimes and landscape patterns, and these patterns often differ significantly from those under natural disturbances. Our objective was to examine the effects of timber harvesting modes on fire regimes and landscape patterns in a boreal forest of Northeast China. We used a spatially explicit landscape model, LANDIS, to simulate the changes of forest landscape in the Huzhong forest region of the Great Khingan Mountains under no-cutting, clear-cutting, gradual-cutting and selective-cutting modes. Results showed that：（1） the fine fuel loadings generally decreased while the coarse fuel loadings increased with the increase of timber harvesting intensity;（2） the potential burn area significantly varied among different cutting modes, but the potential fire frequency had no obvious difference. Moreover, timber harvesting generally increased the potential fire risk;（3） clear-cutting mode significantly decreased the mean patch size and the aggregation of larch forests and increased the mean patch size and the aggregation of white birch forests. Therefore, clear-cutting mode should be abandoned, and selective-cutting mode be recommended for the sustainable forest management in the Great Khingan Mountains.
基金supported from the Slovak Scientific Grant Agency VEGA project no. 1/0282/ 11VVGS grant (Faculty of Science, P.J. Safárik University, Kosice) no. 9/2011
文摘The study aimed to assess the response of ep- and hemiedaphic Collembola communities(activity, richness, community structure) to a disturbance, the subsequent management regime and to the season(summer, winter) in a High Tatra Mountains spruce forest destroyed by a windstorm.Fire and clear-cut resulted in an initial increase in the activity of Collembola inhabiting open areas,opportunistic or generalist species, while forest specialists diminished in numbers or disappeared.Our results indicated that treatment with nonextracted fallen trees(NEX) provided a better chance for forest species to survive compared with their survival in open habitats of extracted(EXT) and wildfire(FIR) treatments. Great species' potential of NEX treatment was indicated by Chao2 estimator and activity/species rarefaction curves. Communities of NEX treatment were more similar to the reference(REF) treatment, documented by ordination and cluster analyses. Thus, leaving fallen timber after a windthrow to natural process of succession is suitable for survival of forest species and maintenance of diversity in forests restoration than timber extraction.Community structure in wildfire(FIR) stands was the most dissimilar to the other treatments. Most of the species trapped in this treatment belonged to hemiedaphic life forms, while the activity of larger epedaphic species diminished. In contrast, the highest number of trapped Collembola in EXT treatment was connected with the larger-bodied epigeic species with fast dispersal ability. The trapping period affected both the number of individuals and species richness;Collembola activity and species diversity in the individual treatments were lower in winter compared with the summer period. Several species increased activity during the winter period, namely Folsomia penicula, Friesea mirabilis, F. truncata, Hypogastrura socialis and Protaphorura aurantiaca.
