During the period of September 12, 1999 to September 24, 2000, we measured sap flow ofeucalyptus (Euca/yptus urophylla S.T. Blake) plantations using heat pulse technique, and the relevantenvironmental vaiables, such a...During the period of September 12, 1999 to September 24, 2000, we measured sap flow ofeucalyptus (Euca/yptus urophylla S.T. Blake) plantations using heat pulse technique, and the relevantenvironmental vaiables, such as soil evaporation and canopy interception, etc, at Hetou and Jijia sites,Leizhou Peninsula, Guangdong Province. Based on the measurements of sap flow and estimates ofevapotranspiration, the following can be concluded: (1) the maximum of diurnal xylem sap flux density (SFD)at Hetou, where covered with coarse-textured soils formed on Quaternary sediments, was almost twice ofthat at Jijia, where located on clay-rich soils derived from basalt; (2) SFD was highly correlated to watervapor pressure deficit (VPD) of ambient air near the canopy layer, (3) the correlation between SFD and airtemperature also depends on soil properties and soil water potential; (4) the relative differences betweenmeasured and modeled evapotranspiration were small, being 5.26% at Hetou and 6.14% at Jijia; (5) theplantation transpiration accounted for 62.2% and 51.3% of the evapotranspiration at Hetou and Jijia,respectively; and (6) the averaged SFD per unit leaf area (ASPULA) was a good index to estimate theamount of water consumption of tree species.展开更多
Bamboo forest is an important forest type in subtropical and tropical areas.Due to its biological characteristic and growth habits, bamboo is not only an ideal economicinvestment that can be utilized in many different...Bamboo forest is an important forest type in subtropical and tropical areas.Due to its biological characteristic and growth habits, bamboo is not only an ideal economicinvestment that can be utilized in many different manners but also has enormous potential foralleviating many environmental problems facing the world today. This review describes ecologicalfunctions of the bamboo forest on soil erosion control, water conservation, land rehabilitation, andcarbon sequestration.展开更多
With world population growth arable land area is decreasing. Saline soil is an important naturalresource. However it has not been well reclaimed owing to adverse conditions. Forestation is one way of saltysoil utiliza...With world population growth arable land area is decreasing. Saline soil is an important naturalresource. However it has not been well reclaimed owing to adverse conditions. Forestation is one way of saltysoil utilization; on the other hand, it can improve soil quality as well. The mechanism of salinity tolerance isthe basis for tree species selection when planting in salt affected soil. Different plants have various way ofsalinity tolerance, some are salt-exclusion, e.g. Elaeagnus angustifolia; some are salt-secretion, e.g. Tamarixspp.; some are salt-dilution, e.g. Hordeum vulgare; some are salt-avoidance, e.g. Rhizophora apiculata. Treesare favorable, which are salt tolerant and drought or waterlogging tolerant, as well as grow fast. After treespecies have been decided, site preparation including change or exchange of soil is necessary. Meanwhilesuitable density of trees and planting time must be carefully considered in terms of soil conditions andclimatic characteristics. Now a large scale of forests has been established in salt-affected soil in China by themeans discussed in the paper, and protect forest system along coast plays important roles in socio-economicsustainable development and improvement of eco-environment.展开更多
Water harvesting is one of main measures to solve water shortage resulting from less precipitation and erratically seasonal dis- tribution in arid and semi-arid areas. Different types of anti-infiltration treatments i...Water harvesting is one of main measures to solve water shortage resulting from less precipitation and erratically seasonal dis- tribution in arid and semi-arid areas. Different types of anti-infiltration treatments including mechanical and chemical to micro-catchment and their runoff efficiencies had been reported. This paper, through 5 years experiment from 1992 to 1996, is aimed at studying the im- pacts of microcatchment water-harvesting system (MCWHS) with microphytic crust treatment on afforestation on semi-arid Loess Plateau. The results showed that after 3 years of crust inoculation, crust had covered majority of MCWHS and the function of water harvesting had also been demonstrated partially, there were significant difference in soil moisture of shallow soil layer in three typical spring stages be- tween crust cover and control treatments (0.05 level), and about 0.9%-6.04% increase of monthly mean soil moisture within 1m soil layer in spring of late 3 years. The impact of severe spring drought can be alleviated effectively. In the meanwhile, as crust developed on the treated surface, there are significant differences (0.05 level) for tree height (H), diameter at breast height (DBH) and diameter at ground level (DGL) at the end of the study period (1996) with the increases by 22.38%, 17.34%, and 20.49% respectively compared with the con- trol treatment. Microphytic crust, as one of biological infiltration-proof materials, may become the optimized option for revegetation in Chinese Great West Development Strategy due to its self-propagation, non-pollution to water qualities, long use duration and relatively cost effective. Further work should be focused on the selection of endemic crust species and their batch-culture in arid environment.展开更多
OsNHX1 gene (Na+/H+ antiporter gene of Oryza sativa L.) was introduced into Poplar 84K with Agrobacte- rium tumefaciens-mediated transformation. PCR, Southern and Northern blot analysis showed that OsNHX1 gene was inc...OsNHX1 gene (Na+/H+ antiporter gene of Oryza sativa L.) was introduced into Poplar 84K with Agrobacte- rium tumefaciens-mediated transformation. PCR, Southern and Northern blot analysis showed that OsNHX1 gene was incorporated successfully into the genome of Poplar 84K and expressed in these transgenic plants. Salt tolerance test showed that three lines of transgenic plants grew normally in the presence of 200 mmol/L NaCl, while the Na+ content in the leaves of the transgenic plants grown at 200 mmol/L NaCl was significantly higher than that in plants grown at 0 mmol/L NaCl. The osmotic potential in the transgenic plants with high salinity treatment was lower than that of control plants. Our results demonstrate the potential use of these transgenic plants for agricultural use in saline soils.展开更多
Permanent plots in the montane tropical rain forests in Xishuangbanna, southwest China, were established, and different empirical models, based on observation data of these plots in 1992, were built to model diameter ...Permanent plots in the montane tropical rain forests in Xishuangbanna, southwest China, were established, and different empirical models, based on observation data of these plots in 1992, were built to model diameter frequency distributions. The focus of this study is on predicting accuracy of stem number in the larger diameter classes, which is much more important than that of the smaller trees, from the view of forest management, and must be adequately considered in the modelling and estimate. There exist 3 traditional ways of modelling the diameter frequency distribution: the negative exponential function model, limiting line function model, and Weibull distribution model. In this study, a new model, named as the logarithmic J-shape function, together with the others, was experimented and was found as a more suitable model for modelling works in the tropical forests.展开更多
Forty species of Basidiomycota from 21 genera in 15 families, collected from Liuxihe National Forest Park, Guangzhou, China, have values for use by local people. More than half of the species collected are edible, and...Forty species of Basidiomycota from 21 genera in 15 families, collected from Liuxihe National Forest Park, Guangzhou, China, have values for use by local people. More than half of the species collected are edible, and some (Lactarius deliciosus, Boletus spp.) are gathered for commercial consumption in South China. Ten species have medicinal properties, and include Dictyophora, Ganoderma, Pisolithus and Scleroderma. Over 60% species (26 taxa) are ectomycorrhizal involving 12 edible fungi. The most abundant families were the Amanitaceae, Boletaceae and Sclerodermataceae, which form important ectomycorrhizal associations with coniferous and mixed broad-leafed trees in the Park. Prospective uses of these macrofungi are discussed.展开更多
Many studies indicated that the products of biosphere burning have short and long-term effectson the atmosphere. Vegetation burning can produce some gases which have significant influence onenvironment, including some...Many studies indicated that the products of biosphere burning have short and long-term effectson the atmosphere. Vegetation burning can produce some gases which have significant influence onenvironment, including some greenhouse gases as CO2 and CH4, etc. Smoke aerosols produced fromburning also influence global climate and atmospheric chemistry. The paper calculates the consumedbiomass due to forest fires according to the statistics of forest fires from 1991 to 2000 and research resultsof biomass of Chinese forests. During the study period, forest fires burned average 5 Tg ~7 Tg biomasseach year and directly emitted 20.24 Tg^28.56 Tg carbon. In 1991~2000, average emission of carbondioxide and CH4 account for 2.7%~3.9% and 3.3%~4.7% of the total emission of China (calculating withthe data of 2000), respectively.展开更多
Background: The Bar-headed Goose(Anser indicus) is a species that relies heavily on the plateau wetlands of Asia and whose population was thought to be declining. Over the past decade, south-central Tibet, one of the ...Background: The Bar-headed Goose(Anser indicus) is a species that relies heavily on the plateau wetlands of Asia and whose population was thought to be declining. Over the past decade, south-central Tibet, one of the most important wintering grounds, supported large numbers of Bar-headed Geese, but the population had not been regularly monitored in this area.Methods: We surveyed wintering Bar-headed Geese along the Yarlung Zangbo, Lhasa and Nyang Qu rivers, the three major river valleys and their tributaries in south-central Tibet in January 2014 and recorded their location, flock size and habitat utilization. Based on these data and the latest wintering counts elsewhere, we revised the population estimate for this species.Results: We recorded more than 67,000 Bar-headed Geese in south-central Tibet during January 2014. By geographic area, the geese were most abundant in the Lhasa River valley(38.5%) and the Nyang Qu River valley(31.0%), and by administrative division in Lhunzhub(27.2%) and Shigatse(26.7%). Bar-headed Geese were most often observed feeding in winter wheat fields and ploughed fields, resting on pastureland and marshes. The approximate number of 67,000 geese recorded in Tibet is more than four times the estimate of 1993 for the same region and exceeds the most recent world population estimate of 52,000–60,000. Based on our work in Tibet and the latest wintering counts available from other areas, we revised the estimated population size of this species to 97,000–118,000.Conclusions: Our result reveals a remarkable increase in the number of Bar-headed Geese wintering in south-central Tibet. This population increase most likely stems from a proliferation of cropland and especially winter wheat fields in south-central Tibet. This habitat improvement may also cause short-stopping of the Bar-headed Goose and thus reduce mortality of the geese that would otherwise undertake a somewhat daunting trans-Himalayan migration.展开更多
With a vast territory, China is rich in forest resources and diversified environments. The changes in forest resources have a direct bearing on environmental quality. The paper gives a detailed account of the dynamic ...With a vast territory, China is rich in forest resources and diversified environments. The changes in forest resources have a direct bearing on environmental quality. The paper gives a detailed account of the dynamic change in forest resources in China, including the overall process of forest evolution, the status quo and features of the existing forest resources and the development and use of major forest resources. In addition, it analyses the current situation of China's environment and explores the main contributing factors based on the overall environmental situation. In order to achieve sustainable management of forest resources and improve the environment in China, the Chinese government attaches great importance to the protection and development of forest resources as well as environmental development and improvement. The paper gives an overview of the thinking for sustainable forest resource and environmental development in the future and current focus of efforts.展开更多
During 1991~1995, the growth responses of young slash pine to N, P and K fertilizers and rational rate and ratio of fertilizers in yellow-red soil at Fengshushan Forest Farm, Jiangxi Province were studied. N fertilize...During 1991~1995, the growth responses of young slash pine to N, P and K fertilizers and rational rate and ratio of fertilizers in yellow-red soil at Fengshushan Forest Farm, Jiangxi Province were studied. N fertilizer decreased the growth of slash pine, while P not only significantly improved the increment of bottom diameter, height and crown diameter, but also caused earlier canopy closure of the stand. It also had a sustainable effect in the next two years. Slash pine had the most significant response to the treatment of 200 kg P2O5 ha-1, in which tree height, bottom diameter and crown diameter (EW and SN) were increased by 22%, 35%, 20% and 18% in 1994, 21%, 25%, 10% and 10% in 1995, respectively, compared to the control.Although there was no remarkable response to K fertilizer, good growth response to the application of 100 kg P2O5 plus 100 kg K2O ha-1 existed and tree height, bottom diameter and crown diameter (EW and SN)were increased by 31%, 14%, 23% and 21%, respectively, in 1993, compared to the control.展开更多
Computer simulation was carried out on fiber length and width for plantation-grown Chinesewhite poplar (Populus tomentosa Carr. clone) and plantation-grown poplar I-72 (P. x eurumericana (Dode)Guiner cv.). Skewness an...Computer simulation was carried out on fiber length and width for plantation-grown Chinesewhite poplar (Populus tomentosa Carr. clone) and plantation-grown poplar I-72 (P. x eurumericana (Dode)Guiner cv.). Skewness and kurtosis of measured results exhibited that distributions of the fiber length andwidth departured from normal distribution. Three-parameter Weibull density function was used in thisinvestigation and the corresponding program was written with Turbo C. The results showed that profiles ofsimulated length and width histograms were similar to ones of measured histograms, and that there was apretty good agreement between simulated and measured means of fiber length and width. There was a littleinfluence on the simulated means from seed used in random number generator and number of simulatedvariables. That indicated that the simulation was steady when the seed and the number were altered. Differenthistograms can be obtained with different values of the location, the shape, and the scale parameter correspondingto different values of the minimum, the mean, and the standard deviation for fiber length and width. Thesimulation presented here can be used as a tool for the studies on the variations in fiber morphology.展开更多
All plants emit a wide range of volatile compounds, the so-called biogenic volatile organic compounds(BVOC). BVOC emissions have received increased scientific attention in the last two decades because theymay profound...All plants emit a wide range of volatile compounds, the so-called biogenic volatile organic compounds(BVOC). BVOC emissions have received increased scientific attention in the last two decades because theymay profoundly influence the chemical and physical properties of the atmosphere, and may modulate planttolerance to heat, pollutants, oxidative stress and abiotic stresses, and affect plant-plant and plant-insectinteractions. Urban forestry may have a high impact on atmospheric composition, air quality, environment,and quality of life in urban areas. However, few studies have been carried out where the emission of BVOCcould have important consequence for the quality of air and contribute to pollution episodes. A screening ofBVOC emission by the mixed stand constituting urban forests is therefore required if emissions are to bereliably predicted. Monitoring the emission rates simultaneously with measurements of air quality, plantphysiology and micrometeorology on selected urban forests, will allow detailed quantitative information onthe inventory of BVOC emissions by urban vegetation to be compiled. This information will make itpossible to propose an innovative management of urban vegetation in cities characterised by heavy emissionsof anthropogenic pollutants, aiming at the abatement of BVOC emissions through the introduction or selectionof non-BVOC emitting species in urban areas subjected to pollution episodes and in the new afforestationareas covering peri-urban parks, green belts and green corridors between peri-urban rural areas and theconurbations.展开更多
This paper is a summarization on evaluation of value of artificial forest. The main contents include: (i) the difference in concepts between ecological function, ecological efficiency and ecological benefits of artifi...This paper is a summarization on evaluation of value of artificial forest. The main contents include: (i) the difference in concepts between ecological function, ecological efficiency and ecological benefits of artificial forest; (ii) the motive and several taches of economic feedback or compensation for ecological benefit; (iii)the ecological efficiencies of artificial forest and the main correlative factors which includes the ecological efficiencies of artificial forest and the main correlation factors infecting the ecological efficiency; (iv) the basic math correlations between ecological efficiencies of artificial forest and the related factors; (v) service range of the ecological efficiencies of artificial forest; and (vi) the basic principle of measurement of ecological efficiencies of artificial forest. At the end, the basic methods of main ecological efficiencies of artificial forest are expatiated.展开更多
Structural diversity is the key attribute of a stand. A set of biodiversity measures in ecology was introduced in forest management for describing stand structure, of which Shannon information entropy (Shannon index) ...Structural diversity is the key attribute of a stand. A set of biodiversity measures in ecology was introduced in forest management for describing stand structure, of which Shannon information entropy (Shannon index) has been the most widely used measure of species diversity. It is generally thought that tree size diversity could serve as a good proxy for height diversity. However, tree size diversity and height diversity for stand structure is not completely consistent. Stand diameter cannot reflect height information completely. Either tree size diversity or height diversity is one-dimensional information entropy measure. This paper discussed the method of multiple-dimensional information entropy measure with the concept of joint entropy. It is suggested that joint entropy is a good measure for describing overall stand structural diversity.展开更多
The paper gives a brief description about the current main forest fire danger rating systems in the world, which in- clude forest fire danger rating system used in Canada, USA, Australia, and other countries. It show...The paper gives a brief description about the current main forest fire danger rating systems in the world, which in- clude forest fire danger rating system used in Canada, USA, Australia, and other countries. It shows the composition, structure and development of the main fire danger rating systems. The limitations of those systems are also discussed. Through a comparison of the three main forest fire danger rating systems the paper describes their differences on development, fuel complex descriptions, inputs and outputs, and their applications and finds that the technologies of the Canadian forest fire danger rating system can be adopted for China to develop a national forest fire danger rating system. Two steps are needed to develop our own national forest fire danger rating system. Firstly, we apply the CFFDRS directly. Then some studies should be done to calibrate the FDRS to local weather and fuel characteristics.展开更多
The drying characteristic was studied for plantation wood of Chinese fir and poplar, which are typical plantation wood of southern and northern part of China, respectively. Through 100-degree-method the drying charact...The drying characteristic was studied for plantation wood of Chinese fir and poplar, which are typical plantation wood of southern and northern part of China, respectively. Through 100-degree-method the drying characteristic and basic drying condition were gotten, then drying schedule was developed for practical drying, the results showed that the drying schedule is suitable for Chinese fir and poplar plantation lumber, but shrinkage is large. The recommendation was made that enough dead weight is needed to decrease shrinkage in drying process. The drying quality of the two species of lumber is good in conventional drying method.展开更多
With the increase of wood and wood products demands in the world, non-destructive evaluation techniques of wood are more and more important. This article clarifies the importance and present situation of non-destructi...With the increase of wood and wood products demands in the world, non-destructive evaluation techniques of wood are more and more important. This article clarifies the importance and present situation of non-destructive evaluation and introduces some instruments about non-destructive evaluation, and some advice and ideas are put forward.展开更多
文摘During the period of September 12, 1999 to September 24, 2000, we measured sap flow ofeucalyptus (Euca/yptus urophylla S.T. Blake) plantations using heat pulse technique, and the relevantenvironmental vaiables, such as soil evaporation and canopy interception, etc, at Hetou and Jijia sites,Leizhou Peninsula, Guangdong Province. Based on the measurements of sap flow and estimates ofevapotranspiration, the following can be concluded: (1) the maximum of diurnal xylem sap flux density (SFD)at Hetou, where covered with coarse-textured soils formed on Quaternary sediments, was almost twice ofthat at Jijia, where located on clay-rich soils derived from basalt; (2) SFD was highly correlated to watervapor pressure deficit (VPD) of ambient air near the canopy layer, (3) the correlation between SFD and airtemperature also depends on soil properties and soil water potential; (4) the relative differences betweenmeasured and modeled evapotranspiration were small, being 5.26% at Hetou and 6.14% at Jijia; (5) theplantation transpiration accounted for 62.2% and 51.3% of the evapotranspiration at Hetou and Jijia,respectively; and (6) the averaged SFD per unit leaf area (ASPULA) was a good index to estimate theamount of water consumption of tree species.
基金This paper was supported by International Tropical Timber Organization (ITTO) (No. PD10/00REV.2(I,F)) and National Natural Science Foundation of China (No. 30300273).
文摘Bamboo forest is an important forest type in subtropical and tropical areas.Due to its biological characteristic and growth habits, bamboo is not only an ideal economicinvestment that can be utilized in many different manners but also has enormous potential foralleviating many environmental problems facing the world today. This review describes ecologicalfunctions of the bamboo forest on soil erosion control, water conservation, land rehabilitation, andcarbon sequestration.
文摘With world population growth arable land area is decreasing. Saline soil is an important naturalresource. However it has not been well reclaimed owing to adverse conditions. Forestation is one way of saltysoil utilization; on the other hand, it can improve soil quality as well. The mechanism of salinity tolerance isthe basis for tree species selection when planting in salt affected soil. Different plants have various way ofsalinity tolerance, some are salt-exclusion, e.g. Elaeagnus angustifolia; some are salt-secretion, e.g. Tamarixspp.; some are salt-dilution, e.g. Hordeum vulgare; some are salt-avoidance, e.g. Rhizophora apiculata. Treesare favorable, which are salt tolerant and drought or waterlogging tolerant, as well as grow fast. After treespecies have been decided, site preparation including change or exchange of soil is necessary. Meanwhilesuitable density of trees and planting time must be carefully considered in terms of soil conditions andclimatic characteristics. Now a large scale of forests has been established in salt-affected soil in China by themeans discussed in the paper, and protect forest system along coast plays important roles in socio-economicsustainable development and improvement of eco-environment.
文摘Water harvesting is one of main measures to solve water shortage resulting from less precipitation and erratically seasonal dis- tribution in arid and semi-arid areas. Different types of anti-infiltration treatments including mechanical and chemical to micro-catchment and their runoff efficiencies had been reported. This paper, through 5 years experiment from 1992 to 1996, is aimed at studying the im- pacts of microcatchment water-harvesting system (MCWHS) with microphytic crust treatment on afforestation on semi-arid Loess Plateau. The results showed that after 3 years of crust inoculation, crust had covered majority of MCWHS and the function of water harvesting had also been demonstrated partially, there were significant difference in soil moisture of shallow soil layer in three typical spring stages be- tween crust cover and control treatments (0.05 level), and about 0.9%-6.04% increase of monthly mean soil moisture within 1m soil layer in spring of late 3 years. The impact of severe spring drought can be alleviated effectively. In the meanwhile, as crust developed on the treated surface, there are significant differences (0.05 level) for tree height (H), diameter at breast height (DBH) and diameter at ground level (DGL) at the end of the study period (1996) with the increases by 22.38%, 17.34%, and 20.49% respectively compared with the con- trol treatment. Microphytic crust, as one of biological infiltration-proof materials, may become the optimized option for revegetation in Chinese Great West Development Strategy due to its self-propagation, non-pollution to water qualities, long use duration and relatively cost effective. Further work should be focused on the selection of endemic crust species and their batch-culture in arid environment.
基金This work was supported by the National Basic Research Program of China(Grant Nos.G1999011704 and 2003CB114307).
文摘OsNHX1 gene (Na+/H+ antiporter gene of Oryza sativa L.) was introduced into Poplar 84K with Agrobacte- rium tumefaciens-mediated transformation. PCR, Southern and Northern blot analysis showed that OsNHX1 gene was incorporated successfully into the genome of Poplar 84K and expressed in these transgenic plants. Salt tolerance test showed that three lines of transgenic plants grew normally in the presence of 200 mmol/L NaCl, while the Na+ content in the leaves of the transgenic plants grown at 200 mmol/L NaCl was significantly higher than that in plants grown at 0 mmol/L NaCl. The osmotic potential in the transgenic plants with high salinity treatment was lower than that of control plants. Our results demonstrate the potential use of these transgenic plants for agricultural use in saline soils.
文摘Permanent plots in the montane tropical rain forests in Xishuangbanna, southwest China, were established, and different empirical models, based on observation data of these plots in 1992, were built to model diameter frequency distributions. The focus of this study is on predicting accuracy of stem number in the larger diameter classes, which is much more important than that of the smaller trees, from the view of forest management, and must be adequately considered in the modelling and estimate. There exist 3 traditional ways of modelling the diameter frequency distribution: the negative exponential function model, limiting line function model, and Weibull distribution model. In this study, a new model, named as the logarithmic J-shape function, together with the others, was experimented and was found as a more suitable model for modelling works in the tropical forests.
文摘Forty species of Basidiomycota from 21 genera in 15 families, collected from Liuxihe National Forest Park, Guangzhou, China, have values for use by local people. More than half of the species collected are edible, and some (Lactarius deliciosus, Boletus spp.) are gathered for commercial consumption in South China. Ten species have medicinal properties, and include Dictyophora, Ganoderma, Pisolithus and Scleroderma. Over 60% species (26 taxa) are ectomycorrhizal involving 12 edible fungi. The most abundant families were the Amanitaceae, Boletaceae and Sclerodermataceae, which form important ectomycorrhizal associations with coniferous and mixed broad-leafed trees in the Park. Prospective uses of these macrofungi are discussed.
文摘Many studies indicated that the products of biosphere burning have short and long-term effectson the atmosphere. Vegetation burning can produce some gases which have significant influence onenvironment, including some greenhouse gases as CO2 and CH4, etc. Smoke aerosols produced fromburning also influence global climate and atmospheric chemistry. The paper calculates the consumedbiomass due to forest fires according to the statistics of forest fires from 1991 to 2000 and research resultsof biomass of Chinese forests. During the study period, forest fires burned average 5 Tg ~7 Tg biomasseach year and directly emitted 20.24 Tg^28.56 Tg carbon. In 1991~2000, average emission of carbondioxide and CH4 account for 2.7%~3.9% and 3.3%~4.7% of the total emission of China (calculating withthe data of 2000), respectively.
基金funded by the Wildlife Rescue Project from the Department of Wildlife Protection and Nature Reserve Management, State Forestry Administration (SFA) of Chinathe Project of Surveillance of H7N9 in Wild Birds (No. 201404404) from the Department of Science and Technology, SFAco-funded by the International Crane Foundation
文摘Background: The Bar-headed Goose(Anser indicus) is a species that relies heavily on the plateau wetlands of Asia and whose population was thought to be declining. Over the past decade, south-central Tibet, one of the most important wintering grounds, supported large numbers of Bar-headed Geese, but the population had not been regularly monitored in this area.Methods: We surveyed wintering Bar-headed Geese along the Yarlung Zangbo, Lhasa and Nyang Qu rivers, the three major river valleys and their tributaries in south-central Tibet in January 2014 and recorded their location, flock size and habitat utilization. Based on these data and the latest wintering counts elsewhere, we revised the population estimate for this species.Results: We recorded more than 67,000 Bar-headed Geese in south-central Tibet during January 2014. By geographic area, the geese were most abundant in the Lhasa River valley(38.5%) and the Nyang Qu River valley(31.0%), and by administrative division in Lhunzhub(27.2%) and Shigatse(26.7%). Bar-headed Geese were most often observed feeding in winter wheat fields and ploughed fields, resting on pastureland and marshes. The approximate number of 67,000 geese recorded in Tibet is more than four times the estimate of 1993 for the same region and exceeds the most recent world population estimate of 52,000–60,000. Based on our work in Tibet and the latest wintering counts available from other areas, we revised the estimated population size of this species to 97,000–118,000.Conclusions: Our result reveals a remarkable increase in the number of Bar-headed Geese wintering in south-central Tibet. This population increase most likely stems from a proliferation of cropland and especially winter wheat fields in south-central Tibet. This habitat improvement may also cause short-stopping of the Bar-headed Goose and thus reduce mortality of the geese that would otherwise undertake a somewhat daunting trans-Himalayan migration.
文摘With a vast territory, China is rich in forest resources and diversified environments. The changes in forest resources have a direct bearing on environmental quality. The paper gives a detailed account of the dynamic change in forest resources in China, including the overall process of forest evolution, the status quo and features of the existing forest resources and the development and use of major forest resources. In addition, it analyses the current situation of China's environment and explores the main contributing factors based on the overall environmental situation. In order to achieve sustainable management of forest resources and improve the environment in China, the Chinese government attaches great importance to the protection and development of forest resources as well as environmental development and improvement. The paper gives an overview of the thinking for sustainable forest resource and environmental development in the future and current focus of efforts.
文摘During 1991~1995, the growth responses of young slash pine to N, P and K fertilizers and rational rate and ratio of fertilizers in yellow-red soil at Fengshushan Forest Farm, Jiangxi Province were studied. N fertilizer decreased the growth of slash pine, while P not only significantly improved the increment of bottom diameter, height and crown diameter, but also caused earlier canopy closure of the stand. It also had a sustainable effect in the next two years. Slash pine had the most significant response to the treatment of 200 kg P2O5 ha-1, in which tree height, bottom diameter and crown diameter (EW and SN) were increased by 22%, 35%, 20% and 18% in 1994, 21%, 25%, 10% and 10% in 1995, respectively, compared to the control.Although there was no remarkable response to K fertilizer, good growth response to the application of 100 kg P2O5 plus 100 kg K2O ha-1 existed and tree height, bottom diameter and crown diameter (EW and SN)were increased by 31%, 14%, 23% and 21%, respectively, in 1993, compared to the control.
文摘Computer simulation was carried out on fiber length and width for plantation-grown Chinesewhite poplar (Populus tomentosa Carr. clone) and plantation-grown poplar I-72 (P. x eurumericana (Dode)Guiner cv.). Skewness and kurtosis of measured results exhibited that distributions of the fiber length andwidth departured from normal distribution. Three-parameter Weibull density function was used in thisinvestigation and the corresponding program was written with Turbo C. The results showed that profiles ofsimulated length and width histograms were similar to ones of measured histograms, and that there was apretty good agreement between simulated and measured means of fiber length and width. There was a littleinfluence on the simulated means from seed used in random number generator and number of simulatedvariables. That indicated that the simulation was steady when the seed and the number were altered. Differenthistograms can be obtained with different values of the location, the shape, and the scale parameter correspondingto different values of the minimum, the mean, and the standard deviation for fiber length and width. Thesimulation presented here can be used as a tool for the studies on the variations in fiber morphology.
文摘All plants emit a wide range of volatile compounds, the so-called biogenic volatile organic compounds(BVOC). BVOC emissions have received increased scientific attention in the last two decades because theymay profoundly influence the chemical and physical properties of the atmosphere, and may modulate planttolerance to heat, pollutants, oxidative stress and abiotic stresses, and affect plant-plant and plant-insectinteractions. Urban forestry may have a high impact on atmospheric composition, air quality, environment,and quality of life in urban areas. However, few studies have been carried out where the emission of BVOCcould have important consequence for the quality of air and contribute to pollution episodes. A screening ofBVOC emission by the mixed stand constituting urban forests is therefore required if emissions are to bereliably predicted. Monitoring the emission rates simultaneously with measurements of air quality, plantphysiology and micrometeorology on selected urban forests, will allow detailed quantitative information onthe inventory of BVOC emissions by urban vegetation to be compiled. This information will make itpossible to propose an innovative management of urban vegetation in cities characterised by heavy emissionsof anthropogenic pollutants, aiming at the abatement of BVOC emissions through the introduction or selectionof non-BVOC emitting species in urban areas subjected to pollution episodes and in the new afforestationareas covering peri-urban parks, green belts and green corridors between peri-urban rural areas and theconurbations.
文摘This paper is a summarization on evaluation of value of artificial forest. The main contents include: (i) the difference in concepts between ecological function, ecological efficiency and ecological benefits of artificial forest; (ii) the motive and several taches of economic feedback or compensation for ecological benefit; (iii)the ecological efficiencies of artificial forest and the main correlative factors which includes the ecological efficiencies of artificial forest and the main correlation factors infecting the ecological efficiency; (iv) the basic math correlations between ecological efficiencies of artificial forest and the related factors; (v) service range of the ecological efficiencies of artificial forest; and (vi) the basic principle of measurement of ecological efficiencies of artificial forest. At the end, the basic methods of main ecological efficiencies of artificial forest are expatiated.
基金National Natural Science Foundation of China (Grant No. 30371157)
文摘Structural diversity is the key attribute of a stand. A set of biodiversity measures in ecology was introduced in forest management for describing stand structure, of which Shannon information entropy (Shannon index) has been the most widely used measure of species diversity. It is generally thought that tree size diversity could serve as a good proxy for height diversity. However, tree size diversity and height diversity for stand structure is not completely consistent. Stand diameter cannot reflect height information completely. Either tree size diversity or height diversity is one-dimensional information entropy measure. This paper discussed the method of multiple-dimensional information entropy measure with the concept of joint entropy. It is suggested that joint entropy is a good measure for describing overall stand structural diversity.
基金Supported by the Beijing Fund of Natural Science (Grant No. 6042025),China NKBRSF Project (Grant No. 2001CB409600) and the fund of Forest Protection Laboratory,State Forestry Administration
文摘The paper gives a brief description about the current main forest fire danger rating systems in the world, which in- clude forest fire danger rating system used in Canada, USA, Australia, and other countries. It shows the composition, structure and development of the main fire danger rating systems. The limitations of those systems are also discussed. Through a comparison of the three main forest fire danger rating systems the paper describes their differences on development, fuel complex descriptions, inputs and outputs, and their applications and finds that the technologies of the Canadian forest fire danger rating system can be adopted for China to develop a national forest fire danger rating system. Two steps are needed to develop our own national forest fire danger rating system. Firstly, we apply the CFFDRS directly. Then some studies should be done to calibrate the FDRS to local weather and fuel characteristics.
文摘The drying characteristic was studied for plantation wood of Chinese fir and poplar, which are typical plantation wood of southern and northern part of China, respectively. Through 100-degree-method the drying characteristic and basic drying condition were gotten, then drying schedule was developed for practical drying, the results showed that the drying schedule is suitable for Chinese fir and poplar plantation lumber, but shrinkage is large. The recommendation was made that enough dead weight is needed to decrease shrinkage in drying process. The drying quality of the two species of lumber is good in conventional drying method.
文摘With the increase of wood and wood products demands in the world, non-destructive evaluation techniques of wood are more and more important. This article clarifies the importance and present situation of non-destructive evaluation and introduces some instruments about non-destructive evaluation, and some advice and ideas are put forward.
