Soil organic carbon in forest affects nutrient availability,microbial processes,and organic matter inputs.Dominant tree species have increasingly shifted from ectomycorrhizal to arbuscular mycorrhizal associations in ...Soil organic carbon in forest affects nutrient availability,microbial processes,and organic matter inputs.Dominant tree species have increasingly shifted from ectomycorrhizal to arbuscular mycorrhizal associations in subtropical forests.However,the consequences of this shift for soil organic carbon is poorly understood.To address this,a field study was conducted across a natural gradient of arbuscular tree associations to investigate how different mycorrhizal associations affect soil organic carbon quantity,composition,chemical stability,and related soil properties.Soil organic carbon fractions,functional groups,microbial enzyme activities were analyzed.Results showed that increasing arbuscular mycorrhizal dominance was associated with declines in total soil organic carbon,particularly in recalcitrant and aromatic carbon forms.Ectomycorrhizaldominated forests exhibited higher nitrogen availability and elevated nitrogen-hydrolyzing enzyme activity,suggesting enhanced nitrogen acquisition strategies that suppress soil organic carbon decomposition and promote carbon retention.These findings indicate that mycorrhizal-mediated shifts in tree composition may significantly alter soil carbon sequestration potential.Incorporating mycorrhizal functional traits into forest management and carbon modeling could improve predictions of soil organic carbon responses under future environmental change.展开更多
Climate change is the most severe ecological challenge faced by the world today.Forests,the dominant component of terrestrial ecosystems,play a critical role in mitigating climate change due to their powerful carbon s...Climate change is the most severe ecological challenge faced by the world today.Forests,the dominant component of terrestrial ecosystems,play a critical role in mitigating climate change due to their powerful carbon sequestration capabilities.Meanwhile,climate change has also become a major factor affecting the sustainable management of forest ecosystems.Climate-Smart Forestry(CSF)is an emerging concept in sustainable forest management.By utilizing advanced technologies,such as information technology and artificial intelligence,CSF aims to develop innovative and proactive forest management methods and decision-making systems to address the challenges of climate change.CSF aims to enhance forest ecosystem resilience(i.e.,maintain a condition where,even when the state of the ecosystem changes,the ecosystem functions do not deteriorate)through climate change adaptation,improve the mitigation capabilities of forest ecosystems to climate change,maintain high,stable,and sustainable forest productivity and ecosystem services,and ultimately achieve harmonious development between humans and nature.This concept paper:(1)discusses the emergence and development of CSF,which integrates Ecological Forestry,Carbon Forestry,and Smart Forestry,and proposes the concept of CSF;(2)analyzes the goals of CSF in improving forest ecosystem stability,enhancing forest ecosystem carbon sequestration capacity,and advocating the application and development of new technologies in CSF,including artificial intelligence,robotics,Light Detection and Ranging,and forest digital twin;(3)presents the latest practices of CSF based on prior research on forest structure and function using new generation information technologies at Qingyuan Forest,China.From these practices and reflections,we suggested the development direction of CSF,including the key research topics and technological advancement.展开更多
Arbuscular mycorrhizal fungi(AMF)form a near-ubiquitous mutualistic association with roots to help plants withstand harsh environments,and play a key role in the establishment of coastal beach plant communities.Yet li...Arbuscular mycorrhizal fungi(AMF)form a near-ubiquitous mutualistic association with roots to help plants withstand harsh environments,and play a key role in the establishment of coastal beach plant communities.Yet little is known about the structure and composition of AMF communities on coastal beaches of eastern China.In this study,we investigated the occurrence,community composition and diversity of AMF associated with common wild plants on a coastal beach of North Jiangsu,China.Almost all of the local wild species were colonized by AMF except for Chenopodium album L.Thirty-seven AMF species were isolated from the rhizosphere belonging to 12 genera in seven families.Glomus was the dominant genus and Funneliformis mosseae the dominant species.The colonization,spore composition and diversity of AMF were strongly related to edaphic factors.Sodium(Na^(+))ions in the soil significantly and negatively affected the colonization rate by AMF and both soil Na^(+)levels and pH had a significant negative effect on AMF spore density and evenness.However,there was a significant positive correlation between species richness and total organic carbon.The results provide insights into soil factors affecting native AMF communities in coastal beach habitats which could benefit vegetation recovery and soil reclamation efforts.展开更多
Global climate change can affect tree growth and carbon sink function by influencing plant carbohydrate synthesis and utilization,while elevation can be used as an ideal setting under natural conditions to simulate cl...Global climate change can affect tree growth and carbon sink function by influencing plant carbohydrate synthesis and utilization,while elevation can be used as an ideal setting under natural conditions to simulate climate change effects.The effect of elevation on tree growth may depend on organ type.However,the allocation patterns of nonstructural and structural carbohydrates(NSCs and SCs,respectively)in different tree organs and their response to elevation remain unclear.We selected four dominant tree species,Schima superba,Castanopsis eyrei,Castanopsis fargesii and Michelia maudiae,along an elevation gradient from 609 to 1,207 m in subtropical evergreen broad-leaved forests and analyzed leaf,trunk,and fine root NSCs,carbon(C),nitrogen(N)and phosphorus(P)concentrations and the relative abundance of SCs.Leaf NSCs increased initially and then decreased,and trunk NSCs increased with increasing elevation.However,root NSCs decreased with increasing elevation.The relative abundance of SCs in leaves and trunks decreased,while the relative abundance of root SCs increased with increasing elevation.No significant correlations between SCs and NSCs in leaves were detected,while there were negative correlations between SCs and NSCs in trunks,roots,and all organs.Hierarchical partitioning analysis indicated that plant C/N and C/P were the main predictors of changes in SCs and NSCs.Our results suggest that tree organs have divergent responses to elevation and that increasing elevation will inhibit the aboveground part growth and enhance the root growth of trees.A tradeoff between the C distribution used for growth and storage was confirmed along the elevation gradient,which is mainly manifested in the"sink"organs of NSCs.Our results provide insight into tree growth in the context of global climate change scenarios in subtropical forest ecosystems.展开更多
China's Three-North Protective Forest Program(TNP) is the world's most ambitious afforestation project(ongoing from 1978 to 2050), which aims to increase forest coverage through afforestation and reforestation...China's Three-North Protective Forest Program(TNP) is the world's most ambitious afforestation project(ongoing from 1978 to 2050), which aims to increase forest coverage through afforestation and reforestation, protect agriculture, reduce soil erosion, and control desertification. Although TNP has been ongoing for 45 years, its rationales and effects remain uncertain. Here, we conducted a rangewide assessment of TNP by analyzing data from >10,000 scenes of satellite images and >50,000 field survey plots. The TNP range and definitions of shelterbelts, arboreal forests, and shrublands were changed during the study period, but we used the initial TNP range(4.07 million km2) and the definitions in 1978 for keeping the consistency, comparability, and comprehensiveness. The TNP increased forest coverage from 5.05% in 1978 to 9.69% in 2022, with arboreal forests, shrublands, and shelterbelts increasing by 42.5%, 184.4%,and 53.6%, respectively. However, only 40.1% of the 471,113 km2afforested area was established between 1978 and 2022. The wellestablished shelterbelts improved crop yield by 4.3%-9.5%, but only 10.2% of all the farmlands in TNP regions(TNR) were protected. The total area of soil erosion due to hydraulic forces was reduced by 447,363 km2, with 61% of this reduction attributed to TNP. TNP contributed to the reduction of desertification by 15%, largely due to the low rate of afforestation success and the largely decreased grasslands. The total carbon sequestration from TNP was 1.96 Pg C. Moreover, water storage in TNR showed a decreasing trend, but the contribution rate of TNP was only 7.8%. Our results illustrate that forestry eco-engineering projects are feasible in the management and restoration of arid and semi-arid degraded lands, but attention must be paid to fully considering the ecological carrying capacity of water resources, matching the species to sites, strengthening the post-afforestation management, as well as keeping the balances between composite ecosystems.展开更多
Background Three-North Afforestation Program(TNAP)in China is the largest ecological restoration project on Earth(ongoing from 1978 to 2050),harboring a huge area of newly planted forests,which provides a wealth of go...Background Three-North Afforestation Program(TNAP)in China is the largest ecological restoration project on Earth(ongoing from 1978 to 2050),harboring a huge area of newly planted forests,which provides a wealth of goods and ecosystem services that benefit society at levels ranging from region to East Asia.This project-induced carbon(C)sink has been expected to be large,but its size and location remain uncertain.Results In this study,we investigated the changes in the C stocks of biomass,soil C and the C accumulation ben-efited from the ecological effects in the project areas from 1978 to 2017 within the Three-North regions(4.069×10^(6)km^(2)),and evaluated its project-induced C sequestration.Using a combination of remote sensing images,field obser-vations and national forest inventory data,we estimated a total ecosystem sink of 47.06 Tg C per year(1 Tg=10^(12)g)increased by the TNAP implementation.Importantly,we first found that the C sink via the ecological effects of this project could contribute to a high proportion up to 15.94%,indicating a critical role of ecological effects in shaping the distribution of C stocks in the protective forests.This finding suggests that it is necessary to explicitly consider carbon sequestration benefited from the ecological effects when estimating C sink and parameterizing C models of the restoration projects in China and globally.Conclusions Our results update the estimates of C pools in the world’s largest ecological restoration project area,demonstrating that this project has substantially contributed to mitigating the climate change.展开更多
Background:To restore secondary forests(major forest resources worldwide),it is essential to accelerate the natural regeneration of dominant trees by altering micro-environments.Forest gaps are products of various dis...Background:To restore secondary forests(major forest resources worldwide),it is essential to accelerate the natural regeneration of dominant trees by altering micro-environments.Forest gaps are products of various disturbances,ranging from natural storms or wildfires to anthropogenic events like logging and slashing-andburning,and sprouts of most tree species with non-structural carbohydrates(NSCs)storage can regenerate from stumps after gap formation.However,how the stump sprouts with diverse NSCs storages and stump sizes(i.e.,diameters)adapt to various micro-environments of within-gap positions remains unclear.Therefore in this study,we monitored the stump sprout regeneration(density,survival,and growth)and NSCs concentrations of three dominant tree species with different shade tolerances and varying stump diameters at five within-gap positions for the first two consecutive years after gap formation.Results:Stump diameter was positively correlated with sprout density,growth,and survival of all three tree species,but insignificantly related with sprout NSCs concentrations at the early stage after gap formation.The effect of within-gap position on sprout NSCs concentrations was different among species.After an environmental adaptation of two growing seasons,the north of gap(higher light availability and lower soil moisture habitat)was the least conducive for shade-intolerant Quercus mongolica to accumulate leaf NSCs,and the east of gap(shadier and drier habitat)was conducive to increasing the leaf NSCs concentrations of shade-tolerant Tilia mandshurica.Conclusions:Within-gap position significantly affected leaf NSCs concentrations of all three tree species,but most of the sprout growth,survival,and stem NSCs concentrations were independent of the various within-gap positions.Besides stump diameter,the NSCs stored in stump and root systems and the interspecific differences in shade tolerance also contributed more in sprout regeneration at the early stage(2 years)of gap formation.A prolonged monitoring(>10 years)is needed to further examine the long-term effects of stump diameter and within-gap position on sprout regeneration.All of these findings could be applied to gap-based silviculture by promoting sprout regeneration of dominant tree species with different shade tolerances,which would help accelerate the restoration of temperate secondary forests.展开更多
Background:Granivore-mediated seed dispersal is susceptible to changes in seed availability and silvicultural management,which alters synzoochorous interactions in the antagonism-mutualism continuum and affects the se...Background:Granivore-mediated seed dispersal is susceptible to changes in seed availability and silvicultural management,which alters synzoochorous interactions in the antagonism-mutualism continuum and affects the seed dispersal effectiveness(SDE),and eventually,the plant recruitment.We conducted a whole-year study of seed addi-tion to quantify the granivores-Korean pine(Pinus koraiensis)synzoochorous interactions and the SDE in the same sec-ondary forests with two treatments.Both treatments had seed source limitations:one was caused by the disappear-ance of Korean pine due to the historical disturbance,the other by pinecone harvesting in Korean pine plantations adjacent to the secondary forests.Thinning with different intensities(control,25%,and 50%)were also performed to further explore the synzoochorous interactions and SDE in response to silvicultural management in the second type of forests.Results:Source limitation increased the proportion of pre-and post-dispersal seed predation,and made the granivores-Korean pine interaction shift more towards antagonism,with the estimated SDE of 2.31 and 3.60,respec-tively,for the secondary forests without and with Korean pine.Thinning with different intensities did not alleviate the reactions towards antagonism but altered SDE;granivores occurrence decreased,but the proportion of pre-and post-dispersal seed predation increased,resulting in a fivefold decreased seedling recruitment in 25%thinning(the lowest SDE of 0.26).Conclusion:The source limitation coupling thinning biased the synzoochorous interactions more towards antago-nism and significantly lowered granivore-mediated SDE,which limited the successful recruitment of Korean pine in secondary forests.Forest managers should control pinecone harvesting,protect the synzoochorous interaction,and take into account masting event for Korean pine regeneration in the future.展开更多
We investigated the effects of climate on Yeddo spruce (Picea jezoensis)radial growth along altitudinal gradients in the subalpine forests of Changbai Mountains using dendroclimatic analyses. Yeddo spruce at its lower...We investigated the effects of climate on Yeddo spruce (Picea jezoensis)radial growth along altitudinal gradients in the subalpine forests of Changbai Mountains using dendroclimatic analyses. Yeddo spruce at its lower and upper distribution limits was more sensitive to the climate. Despite precipitation being generally considered sufficient, we found that precipitation significantly affected Yeddo spruce radial growth. Yeddo spruce at its lower distribution limit was much more affected by precipitation while Yeddo spruce at its upper distribution limit was much more affected by minimum temperature. Yeddo spruce at its medial altitude was affected by sunshine ratio. These results demonstrated that climate affected Yeddo spruce growth differently depending on its altitudinal distributions in the Changbai Mountains. Both temperature and precipitation in the annualization period significantly correlated with Yeddo spruce radial growth. However, warmer signals were not reflected in radial growth trend during the past 20 years because annual total precipitation declined during the same period. It appeared that the climate affected tree rings growth by altering soil moisture availability.展开更多
Soil phosphorus(P)availability is essential for forest productivity and stability,yet the long-term effects of nitrogen(N)and P fertilization on its mobilization remain unclear.To address this,we conducted a 10-year f...Soil phosphorus(P)availability is essential for forest productivity and stability,yet the long-term effects of nitrogen(N)and P fertilization on its mobilization remain unclear.To address this,we conducted a 10-year field experiment in Metasequoia glyptostroboides plantations under a subtropical monsoon climate,assessing the responses of soil chemical property,enzyme activity,microbial biomass,and P cycling indices and fractions to five independent levels each of N(0,56,168,280,336 kg ha^(-1))and P(0,7.8,31,93,155 kg ha^(-1))fertilization.P fertilization strongly increased available P and inorganic P fractions(Resin-Pi,NaHCO_(3)-Pi,NaOH-Pi),while N fertilization had minimal direct effects.Under N fertilization,available P was primarily influenced by microbial biomass P and carbon,with NaOH-Pi as the dominant supply source.In contrast,under P fertilization,available P was regulated by total P,nitrate nitrogen,and organic carbon,with NaOH-Pi,NaOH-Po,NaHCO_(3)-Pi,and NaHCO_(3)-Po as key fractions.The direct effects of P fertilization,with a pathway coefficient of 0.37,slightly exceeded indirect effects.Overall,our decade-long fertilization trial shows that N fertilization sustains soil P availability chiefly through adaptive microbial processes,whereas P fertilization maintains it largely via direct nutrient inputs.展开更多
基金supported by the National Natural Science Foundation of China(grant numbers 32471851,32171759 and 32201533)Jiangxi Province Ganpo Juncai Support Plan(2024BCE50043).
文摘Soil organic carbon in forest affects nutrient availability,microbial processes,and organic matter inputs.Dominant tree species have increasingly shifted from ectomycorrhizal to arbuscular mycorrhizal associations in subtropical forests.However,the consequences of this shift for soil organic carbon is poorly understood.To address this,a field study was conducted across a natural gradient of arbuscular tree associations to investigate how different mycorrhizal associations affect soil organic carbon quantity,composition,chemical stability,and related soil properties.Soil organic carbon fractions,functional groups,microbial enzyme activities were analyzed.Results showed that increasing arbuscular mycorrhizal dominance was associated with declines in total soil organic carbon,particularly in recalcitrant and aromatic carbon forms.Ectomycorrhizaldominated forests exhibited higher nitrogen availability and elevated nitrogen-hydrolyzing enzyme activity,suggesting enhanced nitrogen acquisition strategies that suppress soil organic carbon decomposition and promote carbon retention.These findings indicate that mycorrhizal-mediated shifts in tree composition may significantly alter soil carbon sequestration potential.Incorporating mycorrhizal functional traits into forest management and carbon modeling could improve predictions of soil organic carbon responses under future environmental change.
基金financially supported by the National Natural Science Foundation of China(32192435)the Application and Demonstration Project of Network Security and Informatization Technology,Chinese Academy of Sciences(CAS-WX2022SF-0101)+1 种基金the Liaoning Provincial Key Research and Development Program(2023021230-JH2/1018)the Youth Innovation Promotion Association of CAS(2023205).
文摘Climate change is the most severe ecological challenge faced by the world today.Forests,the dominant component of terrestrial ecosystems,play a critical role in mitigating climate change due to their powerful carbon sequestration capabilities.Meanwhile,climate change has also become a major factor affecting the sustainable management of forest ecosystems.Climate-Smart Forestry(CSF)is an emerging concept in sustainable forest management.By utilizing advanced technologies,such as information technology and artificial intelligence,CSF aims to develop innovative and proactive forest management methods and decision-making systems to address the challenges of climate change.CSF aims to enhance forest ecosystem resilience(i.e.,maintain a condition where,even when the state of the ecosystem changes,the ecosystem functions do not deteriorate)through climate change adaptation,improve the mitigation capabilities of forest ecosystems to climate change,maintain high,stable,and sustainable forest productivity and ecosystem services,and ultimately achieve harmonious development between humans and nature.This concept paper:(1)discusses the emergence and development of CSF,which integrates Ecological Forestry,Carbon Forestry,and Smart Forestry,and proposes the concept of CSF;(2)analyzes the goals of CSF in improving forest ecosystem stability,enhancing forest ecosystem carbon sequestration capacity,and advocating the application and development of new technologies in CSF,including artificial intelligence,robotics,Light Detection and Ranging,and forest digital twin;(3)presents the latest practices of CSF based on prior research on forest structure and function using new generation information technologies at Qingyuan Forest,China.From these practices and reflections,we suggested the development direction of CSF,including the key research topics and technological advancement.
基金funded by the Agricultural Science and Technology Independent Innovation Fund of Jiangsu Province of China[Grant No.CX(17)004]the National Special Fund for Forestry Scientific Research in the Public Interest(Grant No.201504406)+2 种基金Major Fund for Natural Science of Jiangsu Higher Education Institutions(Grant No.15KJA220004)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Doctorate Fellowship Foundation of Nanjing Forestry University(2169125)。
文摘Arbuscular mycorrhizal fungi(AMF)form a near-ubiquitous mutualistic association with roots to help plants withstand harsh environments,and play a key role in the establishment of coastal beach plant communities.Yet little is known about the structure and composition of AMF communities on coastal beaches of eastern China.In this study,we investigated the occurrence,community composition and diversity of AMF associated with common wild plants on a coastal beach of North Jiangsu,China.Almost all of the local wild species were colonized by AMF except for Chenopodium album L.Thirty-seven AMF species were isolated from the rhizosphere belonging to 12 genera in seven families.Glomus was the dominant genus and Funneliformis mosseae the dominant species.The colonization,spore composition and diversity of AMF were strongly related to edaphic factors.Sodium(Na^(+))ions in the soil significantly and negatively affected the colonization rate by AMF and both soil Na^(+)levels and pH had a significant negative effect on AMF spore density and evenness.However,there was a significant positive correlation between species richness and total organic carbon.The results provide insights into soil factors affecting native AMF communities in coastal beach habitats which could benefit vegetation recovery and soil reclamation efforts.
基金the National Natural Science Foundation of China(32260379&32371852)the Jiangxi Provincial Natural Science Foundation(20224ACB215005)
文摘Global climate change can affect tree growth and carbon sink function by influencing plant carbohydrate synthesis and utilization,while elevation can be used as an ideal setting under natural conditions to simulate climate change effects.The effect of elevation on tree growth may depend on organ type.However,the allocation patterns of nonstructural and structural carbohydrates(NSCs and SCs,respectively)in different tree organs and their response to elevation remain unclear.We selected four dominant tree species,Schima superba,Castanopsis eyrei,Castanopsis fargesii and Michelia maudiae,along an elevation gradient from 609 to 1,207 m in subtropical evergreen broad-leaved forests and analyzed leaf,trunk,and fine root NSCs,carbon(C),nitrogen(N)and phosphorus(P)concentrations and the relative abundance of SCs.Leaf NSCs increased initially and then decreased,and trunk NSCs increased with increasing elevation.However,root NSCs decreased with increasing elevation.The relative abundance of SCs in leaves and trunks decreased,while the relative abundance of root SCs increased with increasing elevation.No significant correlations between SCs and NSCs in leaves were detected,while there were negative correlations between SCs and NSCs in trunks,roots,and all organs.Hierarchical partitioning analysis indicated that plant C/N and C/P were the main predictors of changes in SCs and NSCs.Our results suggest that tree organs have divergent responses to elevation and that increasing elevation will inhibit the aboveground part growth and enhance the root growth of trees.A tradeoff between the C distribution used for growth and storage was confirmed along the elevation gradient,which is mainly manifested in the"sink"organs of NSCs.Our results provide insight into tree growth in the context of global climate change scenarios in subtropical forest ecosystems.
基金supported by the National Natural Science Foundation of China (32192435, 31025007)CAS Key Research Program of Frontier Sciences (QYZDJ-SSW-DQC027)+1 种基金the Knowledge Innovation Program of Chinese Academy of Sciences (KZCX1-YW-08-02)the Consultation Project supported by Divisions of the Chinese Academy of Sciences (2019-ZW09-A032)。
文摘China's Three-North Protective Forest Program(TNP) is the world's most ambitious afforestation project(ongoing from 1978 to 2050), which aims to increase forest coverage through afforestation and reforestation, protect agriculture, reduce soil erosion, and control desertification. Although TNP has been ongoing for 45 years, its rationales and effects remain uncertain. Here, we conducted a rangewide assessment of TNP by analyzing data from >10,000 scenes of satellite images and >50,000 field survey plots. The TNP range and definitions of shelterbelts, arboreal forests, and shrublands were changed during the study period, but we used the initial TNP range(4.07 million km2) and the definitions in 1978 for keeping the consistency, comparability, and comprehensiveness. The TNP increased forest coverage from 5.05% in 1978 to 9.69% in 2022, with arboreal forests, shrublands, and shelterbelts increasing by 42.5%, 184.4%,and 53.6%, respectively. However, only 40.1% of the 471,113 km2afforested area was established between 1978 and 2022. The wellestablished shelterbelts improved crop yield by 4.3%-9.5%, but only 10.2% of all the farmlands in TNP regions(TNR) were protected. The total area of soil erosion due to hydraulic forces was reduced by 447,363 km2, with 61% of this reduction attributed to TNP. TNP contributed to the reduction of desertification by 15%, largely due to the low rate of afforestation success and the largely decreased grasslands. The total carbon sequestration from TNP was 1.96 Pg C. Moreover, water storage in TNR showed a decreasing trend, but the contribution rate of TNP was only 7.8%. Our results illustrate that forestry eco-engineering projects are feasible in the management and restoration of arid and semi-arid degraded lands, but attention must be paid to fully considering the ecological carrying capacity of water resources, matching the species to sites, strengthening the post-afforestation management, as well as keeping the balances between composite ecosystems.
基金supported by grants from National Key R&D Program of China(2020YFA0608100)CAS Key Research Program of Frontier Sciences(QYZDJ-SSW-DQC027)+2 种基金National Natural Science Foundation of China(31025007)the Knowledge Innovation Program of Chinese Academy of Sciences(KZCX1-YW-08-02)the Consultation Project supported by Divisions of the Chinese Academy of Sciences(2019-ZW09-A-032).
文摘Background Three-North Afforestation Program(TNAP)in China is the largest ecological restoration project on Earth(ongoing from 1978 to 2050),harboring a huge area of newly planted forests,which provides a wealth of goods and ecosystem services that benefit society at levels ranging from region to East Asia.This project-induced carbon(C)sink has been expected to be large,but its size and location remain uncertain.Results In this study,we investigated the changes in the C stocks of biomass,soil C and the C accumulation ben-efited from the ecological effects in the project areas from 1978 to 2017 within the Three-North regions(4.069×10^(6)km^(2)),and evaluated its project-induced C sequestration.Using a combination of remote sensing images,field obser-vations and national forest inventory data,we estimated a total ecosystem sink of 47.06 Tg C per year(1 Tg=10^(12)g)increased by the TNAP implementation.Importantly,we first found that the C sink via the ecological effects of this project could contribute to a high proportion up to 15.94%,indicating a critical role of ecological effects in shaping the distribution of C stocks in the protective forests.This finding suggests that it is necessary to explicitly consider carbon sequestration benefited from the ecological effects when estimating C sink and parameterizing C models of the restoration projects in China and globally.Conclusions Our results update the estimates of C pools in the world’s largest ecological restoration project area,demonstrating that this project has substantially contributed to mitigating the climate change.
基金supported by grants from the Strategic Leading Science&Technology Programme,CAS(XDA23070100)National Natural Science Foundation of China(U1808201,31330016)Liaoning Revitalization Talents Program(XLYC1807102).
文摘Background:To restore secondary forests(major forest resources worldwide),it is essential to accelerate the natural regeneration of dominant trees by altering micro-environments.Forest gaps are products of various disturbances,ranging from natural storms or wildfires to anthropogenic events like logging and slashing-andburning,and sprouts of most tree species with non-structural carbohydrates(NSCs)storage can regenerate from stumps after gap formation.However,how the stump sprouts with diverse NSCs storages and stump sizes(i.e.,diameters)adapt to various micro-environments of within-gap positions remains unclear.Therefore in this study,we monitored the stump sprout regeneration(density,survival,and growth)and NSCs concentrations of three dominant tree species with different shade tolerances and varying stump diameters at five within-gap positions for the first two consecutive years after gap formation.Results:Stump diameter was positively correlated with sprout density,growth,and survival of all three tree species,but insignificantly related with sprout NSCs concentrations at the early stage after gap formation.The effect of within-gap position on sprout NSCs concentrations was different among species.After an environmental adaptation of two growing seasons,the north of gap(higher light availability and lower soil moisture habitat)was the least conducive for shade-intolerant Quercus mongolica to accumulate leaf NSCs,and the east of gap(shadier and drier habitat)was conducive to increasing the leaf NSCs concentrations of shade-tolerant Tilia mandshurica.Conclusions:Within-gap position significantly affected leaf NSCs concentrations of all three tree species,but most of the sprout growth,survival,and stem NSCs concentrations were independent of the various within-gap positions.Besides stump diameter,the NSCs stored in stump and root systems and the interspecific differences in shade tolerance also contributed more in sprout regeneration at the early stage(2 years)of gap formation.A prolonged monitoring(>10 years)is needed to further examine the long-term effects of stump diameter and within-gap position on sprout regeneration.All of these findings could be applied to gap-based silviculture by promoting sprout regeneration of dominant tree species with different shade tolerances,which would help accelerate the restoration of temperate secondary forests.
基金supported by the National Natural Science Foundation of China(U1808201,31830016)K.C.Wong Education Foundation(GJTD-2018-07)Liaoning Revitalization Talents Program(XLYC1807102).
文摘Background:Granivore-mediated seed dispersal is susceptible to changes in seed availability and silvicultural management,which alters synzoochorous interactions in the antagonism-mutualism continuum and affects the seed dispersal effectiveness(SDE),and eventually,the plant recruitment.We conducted a whole-year study of seed addi-tion to quantify the granivores-Korean pine(Pinus koraiensis)synzoochorous interactions and the SDE in the same sec-ondary forests with two treatments.Both treatments had seed source limitations:one was caused by the disappear-ance of Korean pine due to the historical disturbance,the other by pinecone harvesting in Korean pine plantations adjacent to the secondary forests.Thinning with different intensities(control,25%,and 50%)were also performed to further explore the synzoochorous interactions and SDE in response to silvicultural management in the second type of forests.Results:Source limitation increased the proportion of pre-and post-dispersal seed predation,and made the granivores-Korean pine interaction shift more towards antagonism,with the estimated SDE of 2.31 and 3.60,respec-tively,for the secondary forests without and with Korean pine.Thinning with different intensities did not alleviate the reactions towards antagonism but altered SDE;granivores occurrence decreased,but the proportion of pre-and post-dispersal seed predation increased,resulting in a fivefold decreased seedling recruitment in 25%thinning(the lowest SDE of 0.26).Conclusion:The source limitation coupling thinning biased the synzoochorous interactions more towards antago-nism and significantly lowered granivore-mediated SDE,which limited the successful recruitment of Korean pine in secondary forests.Forest managers should control pinecone harvesting,protect the synzoochorous interaction,and take into account masting event for Korean pine regeneration in the future.
基金jointly supported by the Overseas Scholar Funding from the Chinese Academy of Sciences(Grant No.C13HK&C13HU)the Opened Research Station of Changbai Mountains Forest Ecosystems and the National Natural Science Foundation of China(Grant Nos.70373044 and 30470302).
文摘We investigated the effects of climate on Yeddo spruce (Picea jezoensis)radial growth along altitudinal gradients in the subalpine forests of Changbai Mountains using dendroclimatic analyses. Yeddo spruce at its lower and upper distribution limits was more sensitive to the climate. Despite precipitation being generally considered sufficient, we found that precipitation significantly affected Yeddo spruce radial growth. Yeddo spruce at its lower distribution limit was much more affected by precipitation while Yeddo spruce at its upper distribution limit was much more affected by minimum temperature. Yeddo spruce at its medial altitude was affected by sunshine ratio. These results demonstrated that climate affected Yeddo spruce growth differently depending on its altitudinal distributions in the Changbai Mountains. Both temperature and precipitation in the annualization period significantly correlated with Yeddo spruce radial growth. However, warmer signals were not reflected in radial growth trend during the past 20 years because annual total precipitation declined during the same period. It appeared that the climate affected tree rings growth by altering soil moisture availability.
基金supported by the National Natural Science Foundation of China(Grant No.32201632)Zhejiang Ten Thousand Talent Scheme-Innovation Leading Talent(Grant No.2023r5251)+1 种基金East China Coastal Shelter Forest Ecosystem National Positioning Observation Research Station(Grant No.RISFZ-2021-08)the RUDN University Strategic Academic Leadership Program.
文摘Soil phosphorus(P)availability is essential for forest productivity and stability,yet the long-term effects of nitrogen(N)and P fertilization on its mobilization remain unclear.To address this,we conducted a 10-year field experiment in Metasequoia glyptostroboides plantations under a subtropical monsoon climate,assessing the responses of soil chemical property,enzyme activity,microbial biomass,and P cycling indices and fractions to five independent levels each of N(0,56,168,280,336 kg ha^(-1))and P(0,7.8,31,93,155 kg ha^(-1))fertilization.P fertilization strongly increased available P and inorganic P fractions(Resin-Pi,NaHCO_(3)-Pi,NaOH-Pi),while N fertilization had minimal direct effects.Under N fertilization,available P was primarily influenced by microbial biomass P and carbon,with NaOH-Pi as the dominant supply source.In contrast,under P fertilization,available P was regulated by total P,nitrate nitrogen,and organic carbon,with NaOH-Pi,NaOH-Po,NaHCO_(3)-Pi,and NaHCO_(3)-Po as key fractions.The direct effects of P fertilization,with a pathway coefficient of 0.37,slightly exceeded indirect effects.Overall,our decade-long fertilization trial shows that N fertilization sustains soil P availability chiefly through adaptive microbial processes,whereas P fertilization maintains it largely via direct nutrient inputs.
