In 1987,a catastrophic fire burned over 1330000 ha in the densely forested area of the Da Hinggan Mountains in the northeastern China.After the fire,intensive management including burned trunk harvesting and coniferou...In 1987,a catastrophic fire burned over 1330000 ha in the densely forested area of the Da Hinggan Mountains in the northeastern China.After the fire,intensive management including burned trunk harvesting and coniferous tree planting had been conducted to accelerate forest restoration.To study the long term effect of these activities on forest recovery,we used a simulation modeling approach to study long-term(300 years) forest dynamics under current planting and natural regeneration scenarios.Results indicate that under tree planting scenario in the severely burned area,the dominant species Dahurian larch(Larix gmelinii) can reach pre-fire level(60% of the area) within 20 years and the maximum abundance can reach nearly 90% within 100 years.While under natural regeneration scenario,it needs about 250 years to reach its pre-fire level.From the perspective of timber production,tree planting can bring twice as much timber volume as that under natural regeneration within 300 years,which is the average longevity of L.gmelinii.It needs about 70 years to reach the timber volume of pre-fire level under the planting scenario,whereas it requires at least 250 years to reach the timber volume of pre-fire level under natural regeneration scenario.Another dominant species Asian White birch(Betula platyphylla) responded negatively to the planting of coniferous species.In general,tree planting of coniferous species after fire can greatly accelerate forest restoration in terms of species abundance and target timber volume,with desirable ecological and economic returns.展开更多
The ecological greening technology of the bare rock area of the arbor governance be-longs to the field of ecological environment restoration, selection of suitable arbors for vegetation restoration in bare rock area, ...The ecological greening technology of the bare rock area of the arbor governance be-longs to the field of ecological environment restoration, selection of suitable arbors for vegetation restoration in bare rock area, vegetation recovery is the primary approach to governance the ecological environment of bare rock area. The reconstruction of bare rock area arbor-shrub-grass ecosystems is a global environmental science problem. Paying attention to Geological conditions with rich rock fissures and abundant groundwater in these fissures, following the idea to reconstruct ecosystem from arbor to shrub and grass and the principle one tree in a baseplate, authors develop a baseplate technique for tree planting in bare rock area. The baseplate includes the parent body, the root, and the cover to prevent evaporation. Especially, there are filled in nutritional soil for the parent body and the root, and the composition of nutritional soil are selected by test in laboratory, while optimal mix ratio of the composition is obtained. Then, application method in field is put forward. The technique can guarantee survival at early stage and growth in the later for tree planting in the baseplate. In particular, the root provides a good channel to guide tree roots into fissure rock and absorb groundwater in rock. Test in field shows that the baseplate technique has strong practicality in vegetation recovery of bare rock area. Test in field shows that the baseplate technique has strong practicality in vegetation recovery of bare rock area in the world.展开更多
Apple is an important cash crop. Because of its rich nutrition, sweet taste and rich iron, it is an important fruit to improve human immunity. Because the demand for apples in the market is relatively large, high yiel...Apple is an important cash crop. Because of its rich nutrition, sweet taste and rich iron, it is an important fruit to improve human immunity. Because the demand for apples in the market is relatively large, high yield and quality should be considered by growers. When fruit trees are cultivated, the technique of dwarfing and close planting can advance the fruit bearing time of fruit trees and help people to obtain economic benefits. At the same time, it can also make efficient use of the orchard. Therefore, in the cultivation stage, people can use this technology to dwarf the apple trees, effectively control the crown area, increase the single volume and increase the economic benefits. Based on the in-depth analysis of the technical points such as dwarfing dense planting and management, and according to the market demand, the present situation of dwarfing cultivation of fruit trees is analyzed, and the technical points such as scientific land selection, dwarfing rootstocks, density control, crown pruning, water and fertilizer management, orchard clearing and pest prevention are put forward, so as to explore the efficient management technology of apple tree dwarfing culture.展开更多
1 When Guo Chengwang started to plant the trees in the Mu Us Desert in northwest China's Shaanxi Province almost 40 years ago,he did not expect his efforts to fight against desertification to last.While just one o...1 When Guo Chengwang started to plant the trees in the Mu Us Desert in northwest China's Shaanxi Province almost 40 years ago,he did not expect his efforts to fight against desertification to last.While just one of the 2,000 saplings that he had planted in 1985 survived,he was still more than exalted to find that poplars(杨树)could grow in the desert.展开更多
Helio da Silva,a retired business executive from Brazil,single⁃handedly planted over 41,000 trees in his hometown of Sao Paulo over the last two decades.Flying over the Brazilian metropolis of Sao Paulo,it's tough...Helio da Silva,a retired business executive from Brazil,single⁃handedly planted over 41,000 trees in his hometown of Sao Paulo over the last two decades.Flying over the Brazilian metropolis of Sao Paulo,it's tough to miss the 3.2-kilometer⁃long and 100⁃meter⁃wide green strip of trees wedged between two of the city's busiest roads.展开更多
Both abiotic conditions and management influence the success of forest restoration.Despite growing interest and practical effort in restoring degraded forest landscapes,understanding of how disparate factors,such as t...Both abiotic conditions and management influence the success of forest restoration.Despite growing interest and practical effort in restoring degraded forest landscapes,understanding of how disparate factors,such as terrain,soil conditions,climate and silvicultural treatments,directly or collectively control species performance and shape community recovery remains limited.In this study,we assessed how topography and management intervention affect seedling survival and growth in the early stages of restoration.To do so,we established seven experimental plots,each measuring 20 m×20 m(400 m2)subdivided into 48 subplots,in coarse,anthropogenic grassland on a mid-elevation mountain slope in Hong Kong,and planted a total of 3975 native tree seedlings belonging to 12 tree species within them.To characterise topography,we modelled the elevation,slope,convexity and aspect of each subplot.Two types of tree guard(enclosed blue plastic sleeve and open yellow mesh),two types of fertiliser(organic and inorganic)and cardboard weeding mats were used to assess the impact of management interventions on the establishment of the seedlings.Survivorship,height and basal diameter were measured at 1,2 and 4 years after planting.We used generalised linear models to examine the effect of these factors and their interactions on seedling survival,and we applied linear models and hierarchical partitioning to explore their relative importance in determining the relative growth rate(RGR)of each species.The most parsimonious models were selected using the Akaike Information Criterion.Survivorship was 98.1%,95.2%and 86.4%across all plots in the first,second and fourth year,respectively.On average,topographic and management variables explained 1.48–3.34%of total variation in RGR,respectively,for all species.The models revealed that type of tree guard,aspect and elevation were the most important factors explaining RGR and survival.Results of hierarchical partitioning by species and growth period showed that the key determinants of performance vary by species and shift over the course of early seedling establishment,emphasising the importance of both spatial and temporal scales in the restoration of degraded tropical forests.Our findings support the use of enclosed tree guards and fertiliser to improve survivorship and growth across a range of broadleaved Asiatic species.All potential limiting factors pertaining to both site factors and management,as well as their interactions,should be considered in restoration planning to maximise restoration success.展开更多
EARLIER this year,on April 3,when U.S.President Donald Trump unveiled his extraordinary raft of tariff measures to the world,Chinese President Xi Jinping was sending a different message to the international community...EARLIER this year,on April 3,when U.S.President Donald Trump unveiled his extraordinary raft of tariff measures to the world,Chinese President Xi Jinping was sending a different message to the international community–he was planting trees on the outskirts of Beijing.To get a sense of the depth of Xi Jinping’s commitment to environmental efforts,it is instructive to read his own words on the topic.The chapter on the building of a Beautiful China in the fifth volume of Xi Jinping:The Governance of China provides a helpful summary of China’s contemporary priorities in environmental governance.It contains excerpts of several speeches,most notably the speech Xi delivered at the National Conference on Eco-Environmental Protection on July 17,2023.展开更多
The 1.5℃ plays an important role on many aspects.It has to do with climate change.And these days,climate change is getting worse and worse.It is now one of the biggest problems in the world.But don’t worry-everyone ...The 1.5℃ plays an important role on many aspects.It has to do with climate change.And these days,climate change is getting worse and worse.It is now one of the biggest problems in the world.But don’t worry-everyone can help with it.First of all,we can plant more trees to cut down the air pollution.What’s more,we should use clean energy,such as wind energy,solar energy and so on.展开更多
Pygmy lorises are arboreal primates primarily found in forest environments across Southeast Asia(Nekaris 2014).Theyhave a diverse diet,including plant secretions,nectar,fruits,invertebrates,tree bark,and bird eggs.All...Pygmy lorises are arboreal primates primarily found in forest environments across Southeast Asia(Nekaris 2014).Theyhave a diverse diet,including plant secretions,nectar,fruits,invertebrates,tree bark,and bird eggs.All 9 known speciesof pygmy lorises are listed as globally endangered species(Nekaris 2014).Pygmy lorises exhibit a range of unique phenotypic characteristics rarely seen among primates.展开更多
Leaf trait patterns and their variations with climate are interpreted as an adaptive adjustment to environment.This study assessed the adaptability of planted black locust (Robinia pseudoacacia L.) based on the analys...Leaf trait patterns and their variations with climate are interpreted as an adaptive adjustment to environment.This study assessed the adaptability of planted black locust (Robinia pseudoacacia L.) based on the analysis of leaf traits and the comparison of its leaf traits with inter-specific ones existing in the same area.We measured some water and N use related leaf traits: leaf dry mass per unit area (LMA) and N,P and K concentrations based on both leaf area (Narea,Parea and Karea) and leaf mass (Nmass,Pmass and Kmass) of R.pseudoacacia at 31 sites along a water stress gradient in North Shaanxi Province,China.The results show that leaves of R.pseudoacacia have high Nmass and low LMA in the study area.High Nmass and low LMA are usually representative of luxurious resource use,and will advance plant resource competitiveness in high-resource conditions.As a whole,LMA-nutrient relationships of R.pseudoacacia display patterns that are fairly similar to the inter-specific relationships in both direction and intensity.The tendency for LMA and Narea to increase with decreasing water availability and the positive correlation between LMA and Narea reflect the trend for R.pseudoacacia to enhance water use efficiency (WUE) at the expense of down-regulated photosynthetic N use efficiency (PNUE) and high construction cost in dry conditions.However,the positive relationship between LMA and Narea in high mean annual precipitation (MAP) area is either unremarkable or reversed with decreasing water availability.This implies a lower photosynthetic capacity and a higher construction cost for high-LMA leaves.The inter-specific relationship between LMA and Narea is positive and does not change with water availability.This difference between inter-species and intra-species may be due to more diversified anatomies and more specialised structures for inter-species than intra-species.The failure of R.pseudoacacia adaption to dry conditions reflected by LMA-Narea relationship may be partially responsible for the emergence of rampike and dwarf forms found frequently in dry conditions.Incorporating intrinsic characteristics of planted trees into vegetation restoration project will be instructive and meaningful for species selection.展开更多
Environmental management intervention benefits have been found to depend on beneficiaries’ unique socioeconomic-environmental factors and understanding these helps generate knowledge guidelines for designing, plannin...Environmental management intervention benefits have been found to depend on beneficiaries’ unique socioeconomic-environmental factors and understanding these helps generate knowledge guidelines for designing, planning and implementation of new interventions. The Ecosystems Alliance (EA) Project in Uganda’s Albertine Rift promoted interventions including, resource access from protected areas, monitoring oil companies’ compliance to set environmental standards, tree planting, lake bank restoration, bee keeping, hay for livestock feeding and cages to shelter communities from crocodiles for four years in Buliisa, Hoima and Kasese district, to, build management capacity of the local communities and institutions to remedy the region’s environment and natural resources which were declining. At the end of the project we interviewed 56 representatives of the project beneficiaries individually and obtained data on benefit level, factors underpinning and perceived livelihoods and environmental impacts of the interventions and used Statistical Package for Social Scientists (SPSS) version 16 (Bryman & Cramer, 2009) to generate percentages (%), correlations with p ≤ 0.05 considered as significant relationship on these. As results, ≥90% of respondents in districts benefited from EA project interventions. Beneficiaries perceived the interventions that enhanced their household incomes and this was especially important for those who were not educated (<em>p</em> = 0.01, for education level);the environment management capacity and this was especially important for women (<em>p</em> = 0.05, for sex) and for households of 4 - 6 members (<em>p</em> = 0.02 with family size);the reduced conflicts with wildlife and this was especially important for households with 4 - 6 members (<em>p</em> = 0.02) and for people who depended on wetlands/wildlife resources (<em>p</em> = 0.00 for both cases) among others. Among constraints to benefit, time of intervention and climatic conditions was especially important among crop farmers (<em>p</em> = 0.04 with occupation) while, intervention not meeting expectation was a factor among beneficiaries in the age group 18 - 31 and 61 - 70 years old (<em>p</em> = 0.01, for age). The respondents recommended future initiatives start with research to determine interventions that match their environment, priority and expectations and these are distributed equitably after prior information/expectation management and technical capacity building.展开更多
Forest recovery plays a critical role in regulating eco-hydrological processes in forested watersheds.However,characteristics of the intra-annual runoff variation associated with different forest recovery patterns rem...Forest recovery plays a critical role in regulating eco-hydrological processes in forested watersheds.However,characteristics of the intra-annual runoff variation associated with different forest recovery patterns remain poorly understood.In this study,three forest change periods were identified,the baseline period(1961-1985),reforestation period(1986-2000)and fruit tree planting period(2001-2016).We selected the magnitude of seasonal runoff(wet and dry seasons)and distribution characteristics,i.e.,non-uniformity coefficient(C_(v)),complete accommodation coefficient(C_(r)),concentration ratio(C_(n)),concentration period(C_(d)),absolute variation ratio(ΔR)and relative variation ratio(C_(max)).The pair-wise approach evaluated the intra-annual runoff variation characteristics between forest change periods.Results indicate that reforestation decreased wet season runoff and increased dry season runoff.In contrast,fruit tree planting increased wet season runoff and had no significant effect on dry season runoff.For intra-annual runoff distribution characteristics,reforestation significantly reduced the C_(v),C_(r),C_(n)and C_(max).Distribution of the intra-annual runoff in the fruit tree planting period was not significantly different from the baseline.We concluded that reforestation reduced the occurance of extreme water conditions in wet and dry seasons and effectively increased the stability of the intra-annual runoff.In contrast,fruit tree planting increased instability and fluctuation of the intra-annual runoff after reforestation.The characteristics of the intra-annual runoff to fruit tree planting was similar to those of the baseline.Therefore,adopting fruit tree planting practices to regulate intra-annual runoff characteristics may not be a practical approach,and impacts of different reforestation practices should be ascertained in our study region.The implications of this study should guide regional land-water management,and this study adds to the understanding of the impacts gained in forest cover on hydrology.展开更多
Changsha-The central govern-ment is urging provincial officials toprotect and expand the green belts intheir areas. Local officials were urged to putthe"green drive"on the top of theiragendas by State Counci...Changsha-The central govern-ment is urging provincial officials toprotect and expand the green belts intheir areas. Local officials were urged to putthe"green drive"on the top of theiragendas by State Councillor ChenJunsheng,addressing a national con-ference on tree planting. Chen said at a conference that anaccountability system monitoringtheir performance would be intro-duced to ensure action on this"veryimportant task." Chen.speaking at the workingconference of National AfforestationCommittee.criticized some officialsfor their"over-enthusiasm in boost-ing the economy"by deforestingsome areas and turning them into"de-velopment zones."展开更多
A direct and elementary method is provided in this paper for counting trees with vertex partition instead of recursion, generating function, functional equation, Lagrange inversion, and matrix methods used before.
Trading water for carbon has cautioned large-scale afforestation in global drylands.However,model simulations suggested that the consumption of soil water could be partially offset by increasing precipitation due to v...Trading water for carbon has cautioned large-scale afforestation in global drylands.However,model simulations suggested that the consumption of soil water could be partially offset by increasing precipitation due to vegetation feedback.A systematic meta-analysis of long-term and large-scale field observations is urgently required to address the abovementioned limitations,and the implementation of large-scale afforestation since 1978 in northern China provides an ideal example.This study collected data comprising 1226 observations from 98 sites in northern China to assess the variation in soil water content(SWC)with stand age after afforestation and discuss the effects of tree species,precipitation and conversions of land use types on SWC.We found that the SWC has been decreased by coniferous forest and broadleaf forest at rates of 0.6 and 3.2 mm decade-1,respectively,since 1978.There is a significant declining trend of SWC with the stand age of plantations,and the optimum growth stage for plantation forest is 0-20 a in northern China.However,we found increases in SWC for the conversion from grassland to forest and in the low-precipitation region,both are corresponding to the increased SWC in coniferous forest.Our study implies that afforestation might lead to a soil water deficit crisis in northern China in the long term at the regional scale but depends on prior land use types,tree taxa and the mean annual precipitation regime,which sheds light on decision-making regarding ecological restoration policies and water resource management in drylands.展开更多
基金Under the auspices of National Natural Science Foundation of China (No 30270225, 40871245, 40331008, 40671013)
文摘In 1987,a catastrophic fire burned over 1330000 ha in the densely forested area of the Da Hinggan Mountains in the northeastern China.After the fire,intensive management including burned trunk harvesting and coniferous tree planting had been conducted to accelerate forest restoration.To study the long term effect of these activities on forest recovery,we used a simulation modeling approach to study long-term(300 years) forest dynamics under current planting and natural regeneration scenarios.Results indicate that under tree planting scenario in the severely burned area,the dominant species Dahurian larch(Larix gmelinii) can reach pre-fire level(60% of the area) within 20 years and the maximum abundance can reach nearly 90% within 100 years.While under natural regeneration scenario,it needs about 250 years to reach its pre-fire level.From the perspective of timber production,tree planting can bring twice as much timber volume as that under natural regeneration within 300 years,which is the average longevity of L.gmelinii.It needs about 70 years to reach the timber volume of pre-fire level under the planting scenario,whereas it requires at least 250 years to reach the timber volume of pre-fire level under natural regeneration scenario.Another dominant species Asian White birch(Betula platyphylla) responded negatively to the planting of coniferous species.In general,tree planting of coniferous species after fire can greatly accelerate forest restoration in terms of species abundance and target timber volume,with desirable ecological and economic returns.
文摘The ecological greening technology of the bare rock area of the arbor governance be-longs to the field of ecological environment restoration, selection of suitable arbors for vegetation restoration in bare rock area, vegetation recovery is the primary approach to governance the ecological environment of bare rock area. The reconstruction of bare rock area arbor-shrub-grass ecosystems is a global environmental science problem. Paying attention to Geological conditions with rich rock fissures and abundant groundwater in these fissures, following the idea to reconstruct ecosystem from arbor to shrub and grass and the principle one tree in a baseplate, authors develop a baseplate technique for tree planting in bare rock area. The baseplate includes the parent body, the root, and the cover to prevent evaporation. Especially, there are filled in nutritional soil for the parent body and the root, and the composition of nutritional soil are selected by test in laboratory, while optimal mix ratio of the composition is obtained. Then, application method in field is put forward. The technique can guarantee survival at early stage and growth in the later for tree planting in the baseplate. In particular, the root provides a good channel to guide tree roots into fissure rock and absorb groundwater in rock. Test in field shows that the baseplate technique has strong practicality in vegetation recovery of bare rock area. Test in field shows that the baseplate technique has strong practicality in vegetation recovery of bare rock area in the world.
文摘Apple is an important cash crop. Because of its rich nutrition, sweet taste and rich iron, it is an important fruit to improve human immunity. Because the demand for apples in the market is relatively large, high yield and quality should be considered by growers. When fruit trees are cultivated, the technique of dwarfing and close planting can advance the fruit bearing time of fruit trees and help people to obtain economic benefits. At the same time, it can also make efficient use of the orchard. Therefore, in the cultivation stage, people can use this technology to dwarf the apple trees, effectively control the crown area, increase the single volume and increase the economic benefits. Based on the in-depth analysis of the technical points such as dwarfing dense planting and management, and according to the market demand, the present situation of dwarfing cultivation of fruit trees is analyzed, and the technical points such as scientific land selection, dwarfing rootstocks, density control, crown pruning, water and fertilizer management, orchard clearing and pest prevention are put forward, so as to explore the efficient management technology of apple tree dwarfing culture.
文摘1 When Guo Chengwang started to plant the trees in the Mu Us Desert in northwest China's Shaanxi Province almost 40 years ago,he did not expect his efforts to fight against desertification to last.While just one of the 2,000 saplings that he had planted in 1985 survived,he was still more than exalted to find that poplars(杨树)could grow in the desert.
文摘Helio da Silva,a retired business executive from Brazil,single⁃handedly planted over 41,000 trees in his hometown of Sao Paulo over the last two decades.Flying over the Brazilian metropolis of Sao Paulo,it's tough to miss the 3.2-kilometer⁃long and 100⁃meter⁃wide green strip of trees wedged between two of the city's busiest roads.
基金The financial support of CLP Holdings Limited is acknowledged for supporting KFBG's ongoing applied forest restoration research.
文摘Both abiotic conditions and management influence the success of forest restoration.Despite growing interest and practical effort in restoring degraded forest landscapes,understanding of how disparate factors,such as terrain,soil conditions,climate and silvicultural treatments,directly or collectively control species performance and shape community recovery remains limited.In this study,we assessed how topography and management intervention affect seedling survival and growth in the early stages of restoration.To do so,we established seven experimental plots,each measuring 20 m×20 m(400 m2)subdivided into 48 subplots,in coarse,anthropogenic grassland on a mid-elevation mountain slope in Hong Kong,and planted a total of 3975 native tree seedlings belonging to 12 tree species within them.To characterise topography,we modelled the elevation,slope,convexity and aspect of each subplot.Two types of tree guard(enclosed blue plastic sleeve and open yellow mesh),two types of fertiliser(organic and inorganic)and cardboard weeding mats were used to assess the impact of management interventions on the establishment of the seedlings.Survivorship,height and basal diameter were measured at 1,2 and 4 years after planting.We used generalised linear models to examine the effect of these factors and their interactions on seedling survival,and we applied linear models and hierarchical partitioning to explore their relative importance in determining the relative growth rate(RGR)of each species.The most parsimonious models were selected using the Akaike Information Criterion.Survivorship was 98.1%,95.2%and 86.4%across all plots in the first,second and fourth year,respectively.On average,topographic and management variables explained 1.48–3.34%of total variation in RGR,respectively,for all species.The models revealed that type of tree guard,aspect and elevation were the most important factors explaining RGR and survival.Results of hierarchical partitioning by species and growth period showed that the key determinants of performance vary by species and shift over the course of early seedling establishment,emphasising the importance of both spatial and temporal scales in the restoration of degraded tropical forests.Our findings support the use of enclosed tree guards and fertiliser to improve survivorship and growth across a range of broadleaved Asiatic species.All potential limiting factors pertaining to both site factors and management,as well as their interactions,should be considered in restoration planning to maximise restoration success.
文摘EARLIER this year,on April 3,when U.S.President Donald Trump unveiled his extraordinary raft of tariff measures to the world,Chinese President Xi Jinping was sending a different message to the international community–he was planting trees on the outskirts of Beijing.To get a sense of the depth of Xi Jinping’s commitment to environmental efforts,it is instructive to read his own words on the topic.The chapter on the building of a Beautiful China in the fifth volume of Xi Jinping:The Governance of China provides a helpful summary of China’s contemporary priorities in environmental governance.It contains excerpts of several speeches,most notably the speech Xi delivered at the National Conference on Eco-Environmental Protection on July 17,2023.
文摘The 1.5℃ plays an important role on many aspects.It has to do with climate change.And these days,climate change is getting worse and worse.It is now one of the biggest problems in the world.But don’t worry-everyone can help with it.First of all,we can plant more trees to cut down the air pollution.What’s more,we should use clean energy,such as wind energy,solar energy and so on.
基金supported by the Shaanxi FundamentalScience Research Project for Chemistry&Biology(grant no.22JHQ049)Basic Research Program of Natural Sciencesof Shaanxi Province(2019JM-339).
文摘Pygmy lorises are arboreal primates primarily found in forest environments across Southeast Asia(Nekaris 2014).Theyhave a diverse diet,including plant secretions,nectar,fruits,invertebrates,tree bark,and bird eggs.All 9 known speciesof pygmy lorises are listed as globally endangered species(Nekaris 2014).Pygmy lorises exhibit a range of unique phenotypic characteristics rarely seen among primates.
基金Under the auspices of National Basic Research Program of China (No.2007CB407205)National High Technology Research and Development Program of China (No.2006BAC01A01)
文摘Leaf trait patterns and their variations with climate are interpreted as an adaptive adjustment to environment.This study assessed the adaptability of planted black locust (Robinia pseudoacacia L.) based on the analysis of leaf traits and the comparison of its leaf traits with inter-specific ones existing in the same area.We measured some water and N use related leaf traits: leaf dry mass per unit area (LMA) and N,P and K concentrations based on both leaf area (Narea,Parea and Karea) and leaf mass (Nmass,Pmass and Kmass) of R.pseudoacacia at 31 sites along a water stress gradient in North Shaanxi Province,China.The results show that leaves of R.pseudoacacia have high Nmass and low LMA in the study area.High Nmass and low LMA are usually representative of luxurious resource use,and will advance plant resource competitiveness in high-resource conditions.As a whole,LMA-nutrient relationships of R.pseudoacacia display patterns that are fairly similar to the inter-specific relationships in both direction and intensity.The tendency for LMA and Narea to increase with decreasing water availability and the positive correlation between LMA and Narea reflect the trend for R.pseudoacacia to enhance water use efficiency (WUE) at the expense of down-regulated photosynthetic N use efficiency (PNUE) and high construction cost in dry conditions.However,the positive relationship between LMA and Narea in high mean annual precipitation (MAP) area is either unremarkable or reversed with decreasing water availability.This implies a lower photosynthetic capacity and a higher construction cost for high-LMA leaves.The inter-specific relationship between LMA and Narea is positive and does not change with water availability.This difference between inter-species and intra-species may be due to more diversified anatomies and more specialised structures for inter-species than intra-species.The failure of R.pseudoacacia adaption to dry conditions reflected by LMA-Narea relationship may be partially responsible for the emergence of rampike and dwarf forms found frequently in dry conditions.Incorporating intrinsic characteristics of planted trees into vegetation restoration project will be instructive and meaningful for species selection.
文摘Environmental management intervention benefits have been found to depend on beneficiaries’ unique socioeconomic-environmental factors and understanding these helps generate knowledge guidelines for designing, planning and implementation of new interventions. The Ecosystems Alliance (EA) Project in Uganda’s Albertine Rift promoted interventions including, resource access from protected areas, monitoring oil companies’ compliance to set environmental standards, tree planting, lake bank restoration, bee keeping, hay for livestock feeding and cages to shelter communities from crocodiles for four years in Buliisa, Hoima and Kasese district, to, build management capacity of the local communities and institutions to remedy the region’s environment and natural resources which were declining. At the end of the project we interviewed 56 representatives of the project beneficiaries individually and obtained data on benefit level, factors underpinning and perceived livelihoods and environmental impacts of the interventions and used Statistical Package for Social Scientists (SPSS) version 16 (Bryman & Cramer, 2009) to generate percentages (%), correlations with p ≤ 0.05 considered as significant relationship on these. As results, ≥90% of respondents in districts benefited from EA project interventions. Beneficiaries perceived the interventions that enhanced their household incomes and this was especially important for those who were not educated (<em>p</em> = 0.01, for education level);the environment management capacity and this was especially important for women (<em>p</em> = 0.05, for sex) and for households of 4 - 6 members (<em>p</em> = 0.02 with family size);the reduced conflicts with wildlife and this was especially important for households with 4 - 6 members (<em>p</em> = 0.02) and for people who depended on wetlands/wildlife resources (<em>p</em> = 0.00 for both cases) among others. Among constraints to benefit, time of intervention and climatic conditions was especially important among crop farmers (<em>p</em> = 0.04 with occupation) while, intervention not meeting expectation was a factor among beneficiaries in the age group 18 - 31 and 61 - 70 years old (<em>p</em> = 0.01, for age). The respondents recommended future initiatives start with research to determine interventions that match their environment, priority and expectations and these are distributed equitably after prior information/expectation management and technical capacity building.
基金supported financially by the Education Department of Jiangxi Provincial(GJJ151141)National Natural Science Foundation of China(31660234)+1 种基金Jiangxi Province Department of Science and Technology(20161BBH80049)the Outstanding Young Scholar of Jiangxi Science and Technology Innovation(20192BCBL23016)。
文摘Forest recovery plays a critical role in regulating eco-hydrological processes in forested watersheds.However,characteristics of the intra-annual runoff variation associated with different forest recovery patterns remain poorly understood.In this study,three forest change periods were identified,the baseline period(1961-1985),reforestation period(1986-2000)and fruit tree planting period(2001-2016).We selected the magnitude of seasonal runoff(wet and dry seasons)and distribution characteristics,i.e.,non-uniformity coefficient(C_(v)),complete accommodation coefficient(C_(r)),concentration ratio(C_(n)),concentration period(C_(d)),absolute variation ratio(ΔR)and relative variation ratio(C_(max)).The pair-wise approach evaluated the intra-annual runoff variation characteristics between forest change periods.Results indicate that reforestation decreased wet season runoff and increased dry season runoff.In contrast,fruit tree planting increased wet season runoff and had no significant effect on dry season runoff.For intra-annual runoff distribution characteristics,reforestation significantly reduced the C_(v),C_(r),C_(n)and C_(max).Distribution of the intra-annual runoff in the fruit tree planting period was not significantly different from the baseline.We concluded that reforestation reduced the occurance of extreme water conditions in wet and dry seasons and effectively increased the stability of the intra-annual runoff.In contrast,fruit tree planting increased instability and fluctuation of the intra-annual runoff after reforestation.The characteristics of the intra-annual runoff to fruit tree planting was similar to those of the baseline.Therefore,adopting fruit tree planting practices to regulate intra-annual runoff characteristics may not be a practical approach,and impacts of different reforestation practices should be ascertained in our study region.The implications of this study should guide regional land-water management,and this study adds to the understanding of the impacts gained in forest cover on hydrology.
文摘Changsha-The central govern-ment is urging provincial officials toprotect and expand the green belts intheir areas. Local officials were urged to putthe"green drive"on the top of theiragendas by State Councillor ChenJunsheng,addressing a national con-ference on tree planting. Chen said at a conference that anaccountability system monitoringtheir performance would be intro-duced to ensure action on this"veryimportant task." Chen.speaking at the workingconference of National AfforestationCommittee.criticized some officialsfor their"over-enthusiasm in boost-ing the economy"by deforestingsome areas and turning them into"de-velopment zones."
基金the National Natural Science Foundation of China (Grant No. 10571013)
文摘A direct and elementary method is provided in this paper for counting trees with vertex partition instead of recursion, generating function, functional equation, Lagrange inversion, and matrix methods used before.
基金supported by the National Key Research and Development Program of China(2022YFF0801803)the National Natural Science Foundation of China(42161144008).
文摘Trading water for carbon has cautioned large-scale afforestation in global drylands.However,model simulations suggested that the consumption of soil water could be partially offset by increasing precipitation due to vegetation feedback.A systematic meta-analysis of long-term and large-scale field observations is urgently required to address the abovementioned limitations,and the implementation of large-scale afforestation since 1978 in northern China provides an ideal example.This study collected data comprising 1226 observations from 98 sites in northern China to assess the variation in soil water content(SWC)with stand age after afforestation and discuss the effects of tree species,precipitation and conversions of land use types on SWC.We found that the SWC has been decreased by coniferous forest and broadleaf forest at rates of 0.6 and 3.2 mm decade-1,respectively,since 1978.There is a significant declining trend of SWC with the stand age of plantations,and the optimum growth stage for plantation forest is 0-20 a in northern China.However,we found increases in SWC for the conversion from grassland to forest and in the low-precipitation region,both are corresponding to the increased SWC in coniferous forest.Our study implies that afforestation might lead to a soil water deficit crisis in northern China in the long term at the regional scale but depends on prior land use types,tree taxa and the mean annual precipitation regime,which sheds light on decision-making regarding ecological restoration policies and water resource management in drylands.
