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1.
China is a mountainous country,and Southwest mountain areas cover the most mountain areas in China and have the most serious problems.Taking Zhaotong city as the study area,based on 902 rural household questionnaires of 11 villages in 2 counties and Tobit model,this paper analyzes the geographical differences and influencing factors of energy consumption for non-production purposes of rural households living in different terrain conditions.This research finds that:(1) Coal takes up the main part of energy consumption in valley areas and coal consumption is mainly affected by per capita cultivated land area,household income,proportion of rural household energy expenditure in total expenditure,coal price,and family population size.Firewood takes up the main part of energy consumption in high mountain areas and firewood consumption is mainly affected by per capita firewood forest area,distance to purchase coal,household income,electricity price,and coal price.(2) Only when the distance is greater than 20 kilometers,that is the average distance of rural households living in middle mountain areas(1,600m~1,800m) to purchase coal,the transportation condition has a significant impact on coal consumption.(3) In high mountain areas,prices of coal and electricity are the main factors influencing energy consumption choice of rural households.Too high prices of coal and electricity would to some extent lead rural households to choose firewood as the main energy consumption type.Compared to coal,rural households prefer to choose electricity.  相似文献   

2.
Agriculture is a large source of carbon emissions. The cropland practices of fertilizer substitution, crop straw and conservation tillage are beneficial and help to rebuild local soil carbon stocks and reduce soil carbon emissions, in addition to reducing the consumption of fertilizers and fossil fuels. These improved cropland practices can directly and indirectly mitigate carbon emissions, benefiting the sustainability of croplands. For these three improved practices, we estimated carbon mitigation potentials in rice, wheat and maize croplands in China. The combined contribution of these practices to carbon mitigation was 38.8 Tg C yr-1, with fertilizer substitution, crop straw return, and conservation tillage contributing 26.6, 3.6 and 8.6 Tg C yr-1, respectively. Rice, wheat and maize croplands had potentials to mitigate 13.4, 11.9 and 15.5 Tg C yr-1, respectively, with the combined direct and indirect potential of 33.8 and 5.0 Tg C yr-1. Because of differences in local climate and specific diets, the regional cropland carbon mitigation potentials differed greatly among provinces in China. In China, 18 provinces had a “target surplus” for which the carbon mitigation from these three practices was larger than the mitigation target set for 2020. At the national level, a net “target surplus” of 4.84 Tg C yr-1 would be attained for Chinese croplands with full implementation of the three improved practices. Regional cooperation must be developed to achieve carbon mitigation targets using such measures as carbon trading, establishing regional associations, and strengthening research programs to improve practices.  相似文献   

3.
The process-oriented model Forest-DNDC describing biogeochemical cycling of C and N and GHGs （greenhouse gases） fluxes （CO2, NO and N2O） in forest ecosystems was applied to simulate carbon sequestration and GHGs emissions in Abies fabric forest of the Gongga Mountains at southeastern edge of the Tibetan Plateau. The results indicated that the simulated gross primary production （GPP） of Abies fabric forest was strongly affected by temperature. The annual total GPP was 24,245.3 kg C ha^-1 yr^-1 for 2005 and 26,318.8 kg C ha^-1 yr^-1 for 2006, respectively. The annual total net primary production （NPP） was 5,935.5 and 4,882.2 kg C ha^-1 yr^-1 for 2005 and 2006, and the annual total net ecosystem production （NEP） was 4,815.4 and 3,512.8 kg C ha^-1 yr^-1 for 2005 and 2006, respectively. The simulated seasonal variation in CO2 emissions generally followed the seasonal variations in temperature and precipitation. The annual total CO2 emissions were 3,109.0 and 4,821.0 kg C ha^-1 yr^-1 for 2005 and 2006, the simulated annual total N2O emissions from forest soil were 1.47 and 1.36 kg N ha^-1 yr^-1 for 2005 and 2006, and the annual total NO emissions were 0.09 and o.12 kg N ha^-1 yr^-1 for 2005 and 2006, respectively.  相似文献   

4.
To improve the burial flux calculations of bioavailable phosphorus(P) and study opal-associated P(Opal-P) in the East China Sea(ECS), surface and core sediments were collected in the Changjiang Estuary(CE) and the south of the Cheju Island. In this study, sedimentary P was operationally divided into seven different forms using modified sedimentary extraction(SEDEX) technique: LSor-P(exchangeable or loosely sorbed P), Fe-P(easily reducible or reactive ferric Fe-bound P), CFA-P(authigenic carbonate fluorapatite and biogenic apatite and CaCO_3-bound P), Detr-P(detrital apatite), Org-P(organic P), Opal-P and Ref-P(refractory P). The data revealed that the concentrations of the seven different P forms rank as Detr-P CFA-P Org-P Ref-P Opal-P Fe-P LSor-P in surface sediments and CFA-P Detr-P Org-P Ref-P Fe-P Opal-P LSor-P in core sediments. The distributions of the total phosphorus(TP), TIP, CFA-P, Detr-P are similar and decrease from the CE to the south of the Cheju Island. Meanwhile, Org-P and Opal-P exhibit different distribution trends; this may be affected by the grain size and TOM. The concentrations of potentially bioavailable P are 9.6-13.0 μmol g~(-1) and 10.0-13.6 μmol g~(-1), representing 61%-70% and 41%-64% of the TP in surface and core sediments, respectively. The concentrations of Opal-P are 0.6-2.3 μmol g~(-1) and 0.6-1.4 μmol g~(-1) in surface and core sediments, accounting for 5.3%-19.8% and 4.2%-10.6% of bioavailable P, respectively. The total burial fluxes of Opal-P and bioavailable P are 1.4×10~9 mol yr~(-1) and 1.1×10~10 mol yr~(-1) in the ECS, respectively. Opal-P represents about 12.7% of potentially bioavailable P, which should be recognized when studying P cycling in marine ecosystems.  相似文献   

5.
Length frequency data of small yellow croaker(Larimichthys polyactis) were acquired from the survey vessel in May,July,September and December,2011 in Haizhou Bay of China.In this study,921 fish individuals were analyzed for the estimation of growth and mortality parameters.Between length and weight,the power coefficient b was 2.7321,2.9703,3.0418 and 2.7252 for the 4 surveying months,respectively.The estimated von Bertalanffy growth function parameters were 230mm(L ∞) and 0.26yr-1(K) as were calculated with ELEFAN method equipped in FiSAT computer package.With length-converted catch curve analysis,the total mortality rate(Z) and its 95% confidence interval were 2.16(1.69-2.64) yr-1,0.59(0.15-1.04) yr-1,1.16(0.80-1.52) yr-1 and 0.96(0.70-1.23) yr-1 for the 4 surveying months,respectively,with the pooled data the value was 1.15(0.81-1.48) yr-1.The natural mortality rate(M) was 0.516 yr-1 as was calculated with Pauly’s equation(the annual average sea water temperature was 11℃).Therefore,fish mortality rate was 0.634 yr-1.The yield-per-recruit analysis indicated that when t c was 1,F max was 0.7 and F 0.1 was 0.55.Currently,the age at first capture is about 1 year and F current was 0.634.Therefore,F current was larger than F 0.1 and less than F max.This indicates that current fish mortality is at a dangerously high level.With Gulland method,the biological reference point for fishery(F opt) was estimated as 0.516 yr-1,lower than current fish mortality.Accordingly,reducing catch in the region was strongly recommended.  相似文献   

6.
During the last 30 years,China has witnessed rapid economic growth and dramatic urbanization,with about 1.2 × 107rural people migrating annually into urban areas.Meanwhile,especially since 1995,the rural population has been declining,which is closely linked to land circulation and the increase in farm size in many villages.Increasing scale of farming operations is often regarded as a key to avoiding the abandonment of farmland and to increasing the income of rural farmers.However,until now,there has been little research on the spatial and temporal variability of farm size at the national level in China.Using data from the national agricultural census and rural household surveys,this study examines the characteristics of land use circulation and the consequent changes in the area of farmland per household.The results show that: 1) 12.2% of rural households were involved in land circulation at the national level.The highest amounts of land circulation have occurred in those provinces where the farmland per capita is more than 0.2 ha or less than 0.1 ha;2) over 80% of households operate less than 0.6 ha of farmland;3) the proportion of mid-sized farms(between 0.2 ha and 0.6 ha per household) has decreased while the smallest and the largest farms have increased.This bears some similarity with the phenomenon known as the ′disappearing middle′,referring to the changes in farm size.This study establishes a framework for interpreting the factors affecting the changes in farm size in China,which include two promoting factors(urbanization and agriculture) and four hindering factors(agricultual land system,household registration,stable clan system,and farmland loss).  相似文献   

7.
Soil erosion and associated off-site sedimentation are threatening the sustainable use of the Three Gorges Dam.To initiate management intervention to reduce sediment yields,there is an increasing need for reliable information on soil erosion in the Three Gorges Reservoir Region(TGRR).The purpose of this study is to use 137 Cs tracing methods to construct a sediment budget for a small agricultural catchment in the TGRR.Cores were taken from a pond and from paddy fields,for 137 Cs measurements.The results show that the average sedimentation rate in the pond since 1963 is 1.50 g cm-2 yr-1 and the corresponding amount of sediment deposited is 1,553 t.The surface erosion rate for the sloping cultivated lands and the sedimentation rate in the paddy fields were estimated to be 3,770 t km-2 yr-1 and 2,600 t km-2 yr-1,respectively.Based on the estimated erosion and deposition rates,and the area of each unit,the post 1970 sediment budget for the catchment has been constructed.A sediment delivery ratio of 0.5 has been estimated for the past 42 years.The data indicate that the sloping cultivated lands are the primary sediment source areas,and that the paddy fields are deposition zones.The typical land use pattern(with the upper parts characterized by sloping cultivated land and the lower parts by paddy fields) plays an important role in reducing sediment yield from agricultural catchments in the TGRR.A 137 Cs profile for the sediment deposited in a pond is shown to provide an effective means of estimating the land surface erosion rate in the upstream catchment.  相似文献   

8.
The aim of the study was to evaluate the impacts of the transition from wood fuel to Liquefied Petroleum Gas(LPG) from energy use and health perspectives along an altitudinal gradient(viz.,lower altitude;middle altitude;and higher altitude) of the Central Himalayas.Empirical field study and questionnaire based survey was conducted forobtaining the data.A total of 20 households from each altitude were selected for obtaining reliable information on the actual quantity of fuelwood consumed.Of the 20 households,five households each based on the family size i.e.,small families(<4 members),medium(5-8 members) and large(>9 members) from all the altitudinal regions were selected.This was followed by an administration of a questionnaire on the quantity of fuelwood consumed.After the completion of the questionnaire survey,the data was validated using a weighted survey for the randomly selected households for obtaining precise information on the actual quantity of fuelwood consumed.Energy analysis is done with respect to the time spent on fuelwood collection and energy value of burning of per kg of fuelwood.Study indicates that declining biomass requirement from forests contributes significantly towards energy conservation,also has positive impact on human health.Per capita annual energy expenditure on collection of fuelwood is 752 MJ which is higher than any other activity in villages of Central Himalaya.The LPG substitution has contributed to energy saving which is equivalent to 2976-3,742 MJ per capita per year in middle and lower altitudes respectively.In the higher altitude the energy saving is calculated to be about 257 MJ per capita per year.Replacing fuelwood with LPG has made positive impact on society in terms of improving the health while reducing diseases that are caused due to indoor air pollution.  相似文献   

9.
Improving knowledge on the ability of bioengineering structures made of willow cuttings to enhance efficient and sustainable sediment trapping in marly gullies in the Southern French Alps under a mountainous Mediterranean climate, to decreasesediment trapped per experiment, the mean annual values reached 0.25, 0.14 and 0.08 m3 yr-1 in experiments C, A and B, respectively. Maximum values for one structure reached 1.94 m3 per year in experiment C. The significance of the volumes ofsediment yield at their outlets, is a key issue today for the international scientific community working in geosciences and ecology. This study therefore aims to assess three real-size experiments(A, B and C) carried out between 2003 and 2013 in this environment. A total of 157 bioengineering structures using purple and white willow(Salix purpurea and Salix incana)cuttings – which have been shown to resprout and survive more than 2 years after their installation,corresponding to brush layers with brush mats on wooden sills(BLM), 1.2 m wide and 2 m long,installed on the floors of 33 experimental marly gullies, were monitored. The results showed that sediment trapping occurred upstream of the vegetation barriers from the 1 st year onwards.Considering the depth of sediment trapped per experiment, the mean annual values reached 11.2 cm yr-1 after 3 years in experiment A, 7.7 cm yr-1 after 2–4 years in experiment C and 5.1 cm yr-1 after 5 years in experiment B. Occasionally, BLMs showed that they could trap up to 16 and 15 cm yr-1 in experiments A and C, respectively. Considering the volumes oftrapped sediment and the sustainability of sediment trapping are discussed, and rules for bioengineering strategies are proposed.  相似文献   

10.
Wind and waves are key components of the climate system as they drive air-sea interactions and influence weather systems and atmospheric circulation. In marine environments, understanding surface wind and wave fields and their evolution over time is important for conducting safe and efficient human activities, such as navigation and engineering. This study considers long-term trends in the sea surface wind speed(WS) and significant wave height(SWH) in the China Seas over the period 1988–2011 using the Cross-Calibrated Multi-Platform(CCMP) ocean surface wind product and a 24-year hindcast wave dataset obtained from the WAVEWATCH-III(WW3) wave model forced with CCMP winds. The long-term trends in WS and SWH in the China Seas are analyzed over the past 24 years to provide a reference point from which to assess future climate change and offshore wind and wave energy resource development in the region. Results demonstrate that over the period 1988–2011 in the China Seas: 1) WS and SWH showed a significant increasing trend of 3.38 cm s~(-1)yr~(-1) and 1.52 cm yr~(-1), respectively; 2) there were notable regional differences in the long-term trends of WS and SWH; 3) areas with strong increasing trends were located mainly in the middle of the Tsushima Strait, the northern and southern areas of the Taiwan Strait, and in nearshore regions of the northern South China Sea; and 4) the long-term trend in WS was closely associated with El Ni?o and a significant increase in the occurrence of gale force winds in the region.  相似文献   

11.
In order to investigate the culture characteristics of two indoor intensive Litopenaeus vannamei farming modes, recirculating aquaculture system (RAS) and water exchange system (WES), this study was carried out to analyze the water quality and nitrogen budget including various forms of nitrogen, microorganism and chlorophyll-a. Nitrogen budget was calculated based on feed input, shrimp harvest, water quality and renewal rate, and collection of bottom mud. Input nitrogen retained in shrimp was 23.58% and 19.10% respectively for WES and RAS, and most of nitrogen waste retained in water and bottom mud. In addition, most of nitrogen in the water of WES was TAN (21.32%) and nitrite (15.30%), while in RAS was nitrate (25.97%), which means that more than 76% of ammonia and nitrite were removed. The effect of microalgae in RAS and WES was negligible. However, bacteria played a great role in the culture system considering the highest cultivable cultivable bacterial populations in RAS and WES were 1.03×1010 cfu mL?1 and 2.92×109 cfu mL?1, respectively. Meanwhile the proportion of bacteria in nitrogen budget was 29.61% and 24.61% in RAS and WES, respectively. RAS and WES could realize shrimp high stocking culture with water consuming rate of 1.25 m3 per kg shrimp and 3.89 m3 per kg shrimp, and power consuming rates of 3.60 kw h per kg shrimp and 2.51 kw h per kg shrimp, respectively. This study revealed the aquatic environment and nitrogen budget of intensive shrimp farming in detail, which provided the scientific basis for improving the industrial shrimp farming.  相似文献   

12.
A study was carried out in district Samba of Western Himalayan province of Jammu and Kashmir of India.The data were collected in an interview schedule in personal interview with 180 household heads.The association between the level of fuelwood consumption（low versus high consumption） and different factors,each individually,was investigated using chi-square test of association at 0.001 level of significance.It was found that out of 25 socio-economic,biophysical and alternate fuel factors,15 factors（each individually） significantly influenced the domestic fuelwood consumption.Logistic regression models of alternate fuel use,social,economic and biophysical factors were developed to identify key variables influencing fuelwood consumption levels within each respective category.A composite model was also developed to identify key factors when all variables in all the pre-said categories were considered simultaneously.Surprisingly,in contrast to expectation the model with alternate fuel use did not provide a good fit.The biophysical model also did not provide a good fit.The economic and composite models were the same with equal level of accuracy of predication.This implies that economic aspects,rather than the availability of alternate fuels,dominate fuelwood consumption levels of rural households.Strategies to increase the exposure of the head of household to outside world needs to formulated to reduce the domestic fuelwood consumption levels.Households nearer to state forests are to be educated about efficient use of fuelwood and be encouraged to intensify use of Liquified Petroleum Gas.The wider implications of study are：the availability of alternate fuels is not a necessary condition to decrease household level domestic fuelwood consumption.Economic factors needs to be considered in designing strategies to reduce fuelwood consumption.Increased employment opportunities would increase the opportunity cost of fuelwood collection and this would reduce its use.  相似文献   

13.
Coal fire burning around the world is an environmental catastrophe characterized by the emission of noxious gases, particulate matter, and condensation by-products. In this study, coal fire temperature is retrieved based on Landsat 5 TM images and Generalized Single-Channel Algorithm (GSCA), in Wuda coalfield, Inner Mongolia, China. Then coal fire zones are extracted by Jenks′ natural breaks and threshold methods based on temperature images. Changes of coal fire zones are analyzed from 1989 to 2008. The results are summarized as follows: 1) The coal fire temperature retrieval method based on Landsat 5 TM and the GSCA model is effective and feasible, because the temperature error is relatively small (from –2.9℃ to +2.6℃) between the measured temperature and the retrieved temperature. 2) The accuracy is relatively high to extract coal fire zones through the Jenks′ natural breaks and threshold methods, because 83.56% of surveyed area is located in the coal fire zones extracted in 2005. 3) The coal fire area increased 9.81 × 10 5 m 2 from 1989 to 2005, and the annual growth is about 6.1 × 10 4 m 2 , with an annual increasing rate of 2.48%. The area of coal fire decreased by 8.1 × 10 5 m 2 from 2005 to 2008.  相似文献   

14.
Ombrotrophic bogs are faithful archive of atmospheric metal deposition,but the potential for fens to reconstruct environmental change is often underestimated.In this study,some new data on the Pb depositional history in northeast China were provided using two 210Pb-dated peat sequences from a poor fen in the Fenghuang Mountain of Heilongjiang province.Anthropogenic,detritic and atmospheric soil sources were discriminated using a two-step sequential digestion(weak acid leaching to liberate mobile Pb which is often regarded as anthropogenic Pb,especially for recent samples)and a ratio of unsupported 210 Pb and supported 210 Pb with the logic of that the 214 Pb mainly represents the residual detritus(constant throughout the core)and the unsupported 210 Pb arises from atmospheric fallout.A higher 210Pb/214 Pb suggests more contributions from atmospheric deposition to the Pb content in the peat,and a ratio of 10 was defined to indicate the boundary between detritic input and atmospheric deposition.The detritic Pbwas estimated to be 10~(-1)3 mg·kg~(-1),the anthropogenic Pb ranged from 10-80 mg·kg~(-1),and the atmospheric soil-derived Pb ranged from 5 mg·kg~(-1) to 30mg·kg~(-1).The history of anthropogenic Pb pollution over the last 150 years was reconstructed,and the calculated Pb deposition rate(AR Pb) ranged from 5to 56 mg·m-2·yr~(-1).Using Ti as a reliable reference,the enrichment factor of Pb(EF Pb) relative to the upper continental crust was calculated.Both AR Pb and EF Pb increased with time,especially after the foundation of the People's Republic of China.This is consistent with increasing industrialization and coal burning in the last 60 years in northeast China.The present record of anthropogenic Pb deposition was consistent with the previous reports and an increasing trend of environmental pollution due to anthropogenic activities,in contrasts to Europe and North America which have experienced a major environmental cleanup.For the first time,this work estimates atmospheric Pb deposition via a minerotrophic peat core in China.This will enhance the use of peat archives for studies of environmental change.  相似文献   

15.
INTRODUCTIONMacrozoobenthos ,amajorgroupofaquaticfauna ,playsanimportantroleinthematerialcycleandenergyflowinawaterecosystem .Inrecentdecades ,interestinthebioenergeticsofthisgrouphasgrownrapidly .Aspectsofthebioenergeticsofmanybenthicfreshwaterspecieshavebeenpub lished .Owingtodifficultyinsamplecollectionandspecimenprocessing ,studiesofthebenthiccom munityhavereceivedlessattention .Withfisherydevelopmentandthelakeeutrophicationproblem ,investigationsontheecologicalfunctionofthelakecommun…  相似文献   

16.
Soil respiration (SR) Wis one of the largest contributors of terrestrial CO_2 to the atmosphere.Environmental as well as physicochemical parameters influence SR and thus, different land use practices impact the emissions of soil CO_2. In this study, we measured SR, bi-monthly, over a one-year period in a terrace tea plantation, a forest tea plantation and a secondary forest, in a subtropical mountain area in Xishuangbanna, China. Along with the measurement of SR rates, soil characteristics for each of the land use systems were investigated. Soil respiration rates in the different land use systems did not differ significantly during the dry season, ranging from2.7±0.2 μmol m~(-2) s~(-1) to 2.8±0.2 μmol m~(-2) s~(-1). During the wet season, however, SR rates were significantly larger in the terrace tea plantation(5.4±0.5 μmol m~(-2)s~(-1)) and secondary forest(4.9±0.4 μmol m~(-2)s~(-1)) than in the forest tea plantation(3.7±0.2 μmol m~(-2) s~(-1)).This resulted in significantly larger annual soil CO_2 emissions from the terrace tea and secondary forest,than from the forest tea plantation. It is likely that these differences in the SR rates are due to the 0.5times lower soil organic carbon concentrations in thetop mineral soil in the forest tea plantation, compared to the terrace tea plantation and secondary forest.Furthermore, we suggest that the lower sensitivity to temperature variation in the forest tea soil is a result of the lower soil organic carbon concentrations. The higher SR rates in the terrace tea plantation were partly due to weeding events, which caused CO_2 emission peaks that contributed almost 10% to the annual CO_2 flux. Our findings suggest that moving away from heavily managed tea plantations towards low-input forest tea can reduce the soil CO_2 emissions from these systems. However, our study is a casestudy and further investigations and upscaling are necessary to show if these findings hold true at a landscape level.  相似文献   

17.
This paper uses the Global Trade Analysis Project(version 7)database to calculate embodied CO2emissions in bilateral trade between China and other countries(regions)based on input-output methods.The sources and flows of embodied CO2emissions in import and export trade of China are analyzed.Results show that the flows of embodied CO2emissions in export trade are highly concentrated.The main flows to the United States(US)and Japan account for 1/4 and 1/7 of the total CO2emissions in export trade,respectively.Concentrated flows of total exports and small differences in export structure are the main reasons for the highly concentrated export trade.The sources of embodied CO2emissions in import trade have relatively low concentration.Taiwan Province of China,Hong Kong Special Administrative Region of China,US,Russia,Republic of Korea,and Japan account for around 7.72%–12.67%of the total embodied CO2emissions in import trade.The relative dispersion of import sources,the impact of the import structure,and the level of production technology in importing countries caused low concentration of CO2emissions in import trade.Overall,the embodied CO2emissions in the export trade of China are higher than those in import trade.As a result,production-based CO2emissions are higher than consumption-based CO2emissions.The difference of 8.96×108t of CO2,which comes mainly from the US,Japan,Germany,and the United Kingdom,accounts for 58.70%of the total difference.Some suggestions,such as improving energy efficiency,alerting high carbon-intensive industries transfer,expanding the market for sharing risks,and prompting the accounting system of consumption-based CO2emissions,are proposed based on the results.  相似文献   

18.
The effects of four ions and eight neuroactive compounds on inducing larval settlement of A. japonicus were assessed in the present study. All bioassays were conducted in 60 × 9 mm Petri dishes, each contained 10 mL of the test solution and 10 doliolaria larvae. There were significant inductive effects of K+(10- mmol L-1), NH+4(0.1 mmol L1), GABA(10-3 mol L-1), acetylcholine(10-5 mol L-1), L-DOPA(10-5 mol L-1), norepinephrine(10-5 mol L-1) and dopamine(10-7 mol L-1 and 10-5 mol L-1) on the settlement of sea cucumber larvae. L-DOPA and dopamine are the most efficient chemical cues to induce A. japonicus larvae to settle. The highest percentage of larval settlement was induced by 10-5 mol L-1 L-DOPA and dopamine(33% and 40%) compared to the control(7%). However, Ca2+, Mg2+, choline, serotonin, and epinephrine were less effective on larval settlement at all tested concentrations. This study evaluated the stability and feasibility of chemical cues for larval settlement in different culture systems, which can be applied to improve the hatchery production of this valuable species.  相似文献   

19.
This paper constructed a carbon emission identity based on five factors: industrial activity, industrial structure, energy intensity, energy mix and carbon emission parameter, and analyzed manufacturing carbon emission trends in Jilin Province at subdivided industrial level through Log-Mean Divisia Index(LMDI) method. Results showed that manufacturing carbon emissions of Jilin Province increased 1.304 × 107 t by 66% between 2004 and 2010. However, 2012 was a remarkable year in which carbon emissions decreased compared with 2011, the first fall since 2004. Industrial activity was the most important factor for the increase of carbon emissions, while energy intensity had the greatest impact on inhibiting carbon emission growth. Despite the impact of industrial structure on carbon emissions fluctuated, its overall trend inhibited carbon emission growth. Further, influences of industrial structure became gradually stronger and surpassed energy intensity in the period 2009–2010. These results conclude that reducing energy intensity is still the main way for carbon emission reduction in Jilin Province, but industrial structure can not be ignored and it has great potential. Based on the analyses, the way of manufacturing industrial structure adjustment for Jilin Province is put forward.  相似文献   

20.
Energy crops are a basic material in the bioenergy industry, and they can also mitigate carbon emissions and have environmental benefits when planted on marginal lands. The aim of this study was to evaluate the potential productivity of energy crops on marginal lands in China. A mechanistic model, combined with energy crop and land use characteristics, and meteorological and soil parameters, was used to simulate the potential productivity of energy crops. There were three main results. 1) The total marginal land in China was determined to be 104.78 × 10~6 ha. The 400-mm precipitation boundary line, which is the dividing line between the semi-humid and semi-arid zones in China, also divided the marginal land into shrub land and sparse forest land in the southeast and bare land, bare rock land, and saline alkali land in the northeast. 2) The total area of the marginal land suitable for planting energy crops was determined to be 55.82 × 10~6 ha, with Xanthoceras sorbifolia and Cerasus humilis mainly grown in the northern China, Jatropha curcas and Cornus wilsoniana mainly grown in the southwest and southeast, and Pistacia chinensis mainly grown in the central area, while also having a northeast-southwest zonal distribution. 3) Taking the highest yield in overlapping areas, the potential productivity of target energy crops was determined to be 32.63 × 10~6 t/yr. Without considering the overlapping areas, the potential productivity was 6.81 × 10~6 t/yr from X. sorbifolia, 8.86 × 10~6 t/yr from C. humilis, 7.18 × 10~6 t/yr from J. curcas, 9.55 × 10~6 t/yr from P. chinensis, and 7.78 × 10~6 t/yr from C. wilsoniana.  相似文献   

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