Nature reserve is the cornerstone of biodiversity conservation,and tourism is an important mode of development of the nature reserve.Based on the landscape scale,3S technology and landscape indices,the paper discussed the change of the landscape patterns in the context of rapid development of tourism in Jiuzhaigou nature reserve during 1975~2007.The results showed that various landscape types of the natural reserve had taken place in different degrees during 33 years.The area of grassland,woodland/shrub,cultivated land had a net decrease,whereas the area of forestland,snow/naked rock,construction land,waters had a net increase.From the point of view of transferred out of proportion,construction land was the largest (13207%),followed by cultivated land (100%),grassland (606%),woodland/shrub(535%),forestland(4.47%),snow/naked rock(321%),whereas waters(207%) was the smallest.Under human activities and natural recovery processes,the degree of landscape fragment continued to increase by 1997;but turned better by 2007.In general,the comprehensive action of forest cutting and natural restoration was the primary driving factor,while the effect of tourism development was relative low for Jiuzhaigou’s landscape changing.Development of tourism had promoted the whole recovery of vegetation in natural reserve,but also added construction land and changed the landscape patterns of vegetation.Only when we instill the principle of “conversation firstly”,and manage scientifically,protection and development can reach a winwin situation.

The purpose of the study is to analyze the spatial variation of 〖JP2〗economy in PanYangtze River Delta.〖JP〗The economic growth in each region not only 〖JP2〗depends on its own characteristics,but also on the neighborhood〖JP〗 regions which it belongs to.Unfortunately,the traditional approaches 〖JP2〗suppose that each region is independent〖JP〗 from others,so they just evaluate the regional disparity variations of "isolated" regions and cannot tell the dynamics of interrelated regions.Methods of ESDA were employed,which 〖JP2〗could incorporate spatial〖JP〗 effects into the analysis of regional disparities,identify global and local disparities at the 〖JP2〗regional scale and visualize〖JP〗 the spatial distribution and patterns through Moran scatter plots or LISA maps.In order to avoid the variation instability of the variable of per capita GDP,methods of spatial autocorrelation indicators adjusted by Empirical Bayes was employed. This paper investigated the spatial dynamics of regional disparities at the municipal level in PanYangtze River Delta by analyzing per capita GDP data,1999~2008.The results indicated that the economy development showed obvious spatial cluster pattern in PanYangtze River Delta.The value of EBI showed a trend of increased volatility; the spatial transfer of clusters and outliers showed definite rules; the economy development showed obvious local spatial disparity pattern.The study indicated the feature of the Yangtze River Delta region with highvalue and the new expansion provinces with lowvalue

Major function oriented zoning (MFOZ) is one of the effective ways to coordinate current rapid economic development and resources and environmental protection in China.Therefore,we set up an integrated indicator system of MFOZ in Yixing of Jiangsu Province, an area with intensive urbanization in the Yangtze River Delta of China.The indicators' weights were determined by principal component analysis (PCA).And then, the projection values of resources and environmental restriction,present development intensity and future development potential in Yixing were calculated by grey relation projection model (GRPM) and classified as three grades (high,medium and low),respectively.According to each town's combination of resources and environment,development intensity and development potential,Yixing was divided into five main function oriented zones by three dimension magic cube classification method (TDMCCM),which consisted of optimized and integrated zone,emphasized development zone,moderately development zone,agriculture and forestry development zone and ecological protection zone.The zoning result prominently indicates the “major function” characteristics of major function oriented zone,which gradually changes from protection type to development type.Moreover,the projection value of evaluation sample calculated by GRPM is the product of the sample module and the angle cosine between evaluation sample and ideal sample. It makes the evaluation results more comprehensive and accurate

There are plenty of small lakes distributed in Hanyang District, and these lakes are almost belonging to type V of water quality due to the inputting of industrial and domestic waste water.Macrobenthos has been widely used to monitor the organic pollution.To detect the extent and distribution of pollution in these lakes (Sanjiao Lake,Moshui Lake,Longyang Lake,Yue Lake,Houguan Lake),this study made investigations of macrobenthos community and researches on their indication to lake environment during 2002~2005.Besides of Houguan Lake with one species of mollusca, the other lakes were only inhabited by pollutanttolerant species,i.e.tubificids (e.g.〖WTBX〗Limnodrilus hoffmeisteri, Branchiura sowerbyi) and chironomids (Tanypus sp,Propsilocerus akamusi,Chironomus plumosus).Statistical analyses revealed that densities of tubificids and chironomids were significantly positively correlated with total nitrogen, phosphorus and Chla (p<005). The correlation coefficients (R²) of regression between tubificid densities and nutrients (TN,TP) were higher than that of chironomids, which indicated that the tubificid densities were more reliable for predicting trophic level than chironomid.The result of water quality bioassessment was almost consistent with the physicalchemical evaluation,i.e.Moshui Lake and Longyang Lake were severely polluted,Yue Lake and Sanjiao Lake were moderately polluted and Houguan Lake was slightly polluted. Not any macrobenthos was collected in the eastern phenolpolluted area of Longyang Lake,which validated the monitoring role of macrobenthos in the longterm effect of pollution. Furthermore,this study utilize〖JP2〗d the spatial pattern of tubificid to indicate the pollution pattern of these lakes.On the basis of environmental analyses,this study validated the reliable role of tubificid in monitoring organic pollution

The black carp (〖WTBX〗Mylopharyngodon piceus〖WTBZ〗),grass carp (〖WTBX〗Ctenopharyngodon idellus〖WTBZ〗),silver carp (〖WTBX〗Hypophthalmichthys molitrix〖WTBZ〗) and bighead carp (〖WTBX〗Aristichthys nobilis〖WTBZ〗) are the four major Chinese carps,and the main species for freshwater fishery and aquaculture in China.They are migratory fishes between rivers and lakes.The Yangtze River is the largest river in China and the third longest river in the world. It is the main habitat for spawning of the four major Chinese carps. As one of the two large lakes maintaining a connection with the mainstream of the Yangtze River,Poyang Lake could be an invaluable feeding ground of the juvenile four major Chinese carps.So far,their migratory mechanism between the Yangtze River and Poyang Lake was still unclear.Time course of the juvenile four major Chinese carps in the Hukou waters of Poyang Lake was investigated from 2007 to 2008.Their peaks appeared in July and August respectively.The peak period of black carp,grass carp and silver carp ranged from middle of July to late August,and the peak of bighead carp appeared in July.The dominant standard length of black carp and bighead carp ranged from 500 to 900 cm respectively,and that of grass carp and silver carp were mostly ranged from 500 to 1499 cm respectively.The dominant species of the juvenile four major Chinese carps collected in the Hukou waters of Poyang Lake was silver carp,and bighead carp was rare.Moreover,the relationships between water level of Poyang Lake (Hukou Station) and their respective daily number were significant positive.The result provided basic data for the research on the migration of the juvenile four major Chinese carps from the Yangtze River to Poyang Lake.Therefore,to protect their resources and increase the knowledge about their migration between the Yangtze River and Poyang Lake,a continued scrutiny seems well justified

In the paper,the chaotic characteristics of hydrological time series from the stations which entering into Poyang lake basin were analyzed.In order to make full use of the abundant evolvement information contained in the monthly runoff series from 1955~2001 on Waizhou,Lijiadu and Dufengkeng stations,the method of CC was used to select the lag time 〖WTBX〗τ〖WTBZ〗 and the phase space of dimensions 〖WTBX〗m〖WTBZ〗.The main quantitative indices such as saturated correlation dimension and the maximum Lyapunov exponent of the monthly runoff series,which could be taken as the chaos features of the hydrology system,were calculated.The saturated correlation dimension was estimated by GP method，and maximal Lyapuonv exponent was calculated by Rosenstein method.The calculated results indicated that monthly runoff time series of the Waizhou,Lijiadu and Dufengkeng stations were all nonintegers.At the same time,the maximum Lyapunov exponents gained from the datum were all positive numbers,which sufficiently showed that the runoff system of Waizhou,Lijiadu and Dufengkeng stations had fractal characteristics and chaotic characteristics.The saturated correlation dimension and the maximum Lyapunov exponent of the monthly runoff series showed that the monthly runoff series was most complex at Waizhou station,the Lijiadu station was secondary,and the Dufenkeng station was least complex.

In the present study, phytoplankton abundance and community structure were investigated and analyzed in June and November 2009 and April 2010 (e.g.highwater period,lowwater period and normalwater period,respectively) in Yuanhe River,a tributary of the lower reaches of Ganjiang River.The results showed that 109 species of phytoplankton were identified,belonging to 61 genera of 6 phyla,among which there were 54 species of 27 genera in Chlorophyta,30 species of 15 genera in Bacillariophyta,12 species of 11 genera in Cyanophyta,6 species of 6 genera in Euglenophyta,4 species of 3 genera in Pyrrophyta and 3 species of 2 genera in Cryptophyta.The phytoplankton abundance ranged from 112×105 to 12920×105 ind./ L.Cyanophyta was the dominant phylum in highwater period and lowwater period,while Bacillariophyta dominated in normalwater period.The constructive species of phytoplankton were the saprobic indicators and they were 〖WTBX〗Fragilaria capucina〖WTBZ〗 and 〖WTBX〗Phormidium tenue〖WTBZ〗 in highwater period,〖WTBX〗Chroomonas caudate〖WTBZ〗 and 〖WTBX〗Synedra amphicephala〖WTBZ〗 in lowwater period and Cyclotella meneghiniana in normalwater period,respectively.Through the analysis of biodiversity index,the ShannonWiener diversity index,Simpson diversity index,Pielou evenness index and Margalef abundance index of phytoplankton were 114~292,045~093,036~092 and 042~278,respectively.Furthermore,using the methods of modified bioindicator community and biodiversity index to biologically assess the water pollution,we found that both methods came to the general same results,It indicated that Yuanhe River was in αβmoderate pollution,and that there was a big difference in pollution levels among different sampling sites

Snow is an important factor in climate change,thus,the extraction of snow cover by Remote Sensing data is of great significance in theory and practice for its advantage of realtime and widerange.Using HJ1A/1B satellite data,combined with the theory of snow remote sensing monitoring,this paper fully analyzed spectral response characteristics of HJ1A/1B satellite data.Then the widely used Normalized Difference Snow Index (NDSI) was introduced to the HJ1A/1B satellite,and a snow cover extraction method HJNDSI which integrated CCD and IRS image was proposed.To avoid the data acquisition problem in the two different sensors caused by the differences of swath width,scanning and other factors,HJNDSI was improved in this paper.Only based on IRS data,an improved extraction method based on the Modified Normalized Difference Snow Index (MNDSI) was put forward.Using multitemporal HJ satellite data,the parameters in the two models were identified.Finally,taking Pulan Xizang as the study area,extraction accuracy of the two results by HJNDSI and HJMNDSI methods was assessed.They were 9766% and 9492%,respectively,and both of them could meet the needs of practical applications.However,HJMNDSI method could guarantee a larger range of snow monitoring in this study.

Through linear trend and moving average method,the variation tendencies of heat island intensity(HII) represented by different temperature types were obtained in Anqing,Wuhu and Nanjing.Then a comparison analysis was made among them.On the basis of principal component analysis,regression models between HII and urbanization index were constructed.The result showed that there was negative correlation between urban scale and the variation velocity of HII represented by annual mean temperature and minmean temperature.However,the relationship between urban scale and the variation velocity of HII represented by annual max-mean temperature did not conform to this rule.Mediumscale city possessed maximum variation velocity of HII,while maximumscale city possessed minimum variation velocity.Cubic regression model all accorded with the relationship models between HII and urbanization index at utmost.Meanwhile,only the relationship model in mediumscale city owned characteristics of Kuznets curve.The main influence factors of heat island for different cities had obvious discrepancies,with economical level,population density and energy consumption for Anqing,urban population proportion,economic level and ecological condition for Wuhu,land use condition and abovementioned factors for Nanjing

Surfaces of precipitation at resolution of 1 km×1 km were generated by the series data from 170 observation stations in Huai River basin from 1961 to 2005,using Kriging interpolation method.Based on the grid data series,the spatial and temporal variability characteristics of precipitation in Huai River basin were analyzed.Results showed that the higher precipitation occurred in the south of the basin,and lower precipitation occurred in the north of the basin,and lower precipitation occurred in the north of the basin.There was no significant trend with large interannual variabilities of annual precipitation in recent 45 years,and the rainfall of various season had different change patterns.The linear trend analyses and MannKendall trend test indicated that the changing trends of precipitation did not arrive at the significant level in Huai River basin.Nevertheless,the interdecadal variabilities of annual and flood season precipitation had obvious phase characteristics.The precipitation present decline trend before 1990s,while an apparent increasing trend after 2000.At present,the precipitation of Huai River basin is in a phase of high climate variability.During recent 45 years,there was an evident variation in the spatial distribution of precipitation in Huai River basin,which was represented by an increase trend of precipitation in the upper and middle Huai River, and a decline trend in the northeast of basin

Sense of place is a hot topic of western recreation geography and environmental psychology.The Influences of tourists’ sense of place on their attitude and behavior towards resource protection is a significant issue of sense of place application study.Taking Jiuzhaigou as the study case,the paper measured tourists’ sense of place and their attitude towards resource protection,and examined the relationship between them by constructing structural equation model.The results showed that natural scenery and socialcultural setting of Jiuzhaigou affected tourism function positively and significantly;natural scenery and tourism function affected tourists’ affectional attachment positively and significantly.Tourists’ attitude towards resource protection was directly influenced by their affectional attachment to Jiuzhaigou positively and significantly.Effects of natural scenery,socialcultural setting and tourism function of Jiuzhaigou on tourists’ attitude towards resource protection were realized thought their affectional attachment,which mediated the relationship between the former three dimensions and tourists’ attitude.Tourists’ experiential evaluation of natural scenery was the primary influencing factor of Jiuzhaigou tourists’ attitude towards resource protection.The higher level of place experience Jiuzhaigou tourists have,the more importance tourists attach to resource protection. Its implication in Jiuzhaigou resource protection was also discussed

Coastal wetlands is an important part of China's wetlands and has various ecological functions.With the arriving of risk society,people have caused environmental damage to coastal wetlands through all kinds of behavior.Thus,the legal system for the protection and management of coastal wetlands has become a priority.Legal adjustment mechanism is the most important part among all types of adjustment mechanisms to deal with the problem of coastal wetlands,but current legal adjustment mechanism can not solve the "Tragedy of the Commons " and balance the interests,According to social development,it is necessary to adopt comprehensive legal adjustment mechanism,that is administrative adjustment mechanism,marketable adjustment mechanism and social adjustment mechanism.The rise of environmental governance theory and the development of third sector lay theoretical and social basis for the comprehensive legal adjustment mechanism of coastal wetlands,through the development of environmental protection industry,establishment of ecological compensation system,perfection of public participation in environmental impact assessment approach and construction of community comanagement model.A variety of legal means,such as administrative guidance,economic incentives and public participation should be uesd to improve the protection and management of coastal wetlands

Soil gross nitrification rates and denitrification rates were determined using the barometric process separation(BaPS)technique in greenhouse vegetable soils in Shanghai Suburb,and the factor analysis were used to evaluate factors affecting soil nitrification and denitrification process.The results showed that there were significant differences in soil gross nitrification rates and denitrification rates among all greenhouse vegetable soils(Oneway Anova,〖WTBX〗p〖WTBZ〗<001).Soil gross nitrification rates ranged from 17758 to 45726 Nug/kg·h,soil denitrification rates ranged from 23151 to 415 Nug/kg·h.Soil gross nitrification rates were positively related to soil nitrate content(〖WTBX〗p〖WTBZ〗<005) and negatively related to soil bulk density p 005).Soil gross denitrification rates were positively related to soil moisture(〖WTBX〗p〖WTBZ〗<005),and to soil organic matter,nitrate〖WTBX〗(p〖WTBZ〗<001).Soil moisture,soil organic matter,nitrate and soil bulk density were the important factors to affect soil nitrification and denitrification process,and these four indices indicated more than 80 percent information of all measured soil indices.Soil gross nitrification and denitrification contribution to the emission of soil N2O were 475%,525%,respectively.Both soil gross nitrification and denitrification were responsible for the nitrogen loss from greenhouse vegetable soils

The rapid increase of nonpoint source pollution has made water quality of Le′an River decline in recent years.Water samples were taken in April,September and December 2009,and land use investigation was carried out in Le′an River watershed for nonpoint source nitrogen pollution study.Using GIS as a tool,spatial information was analyzed to demonstrate the temporal and spatial characteristics of nonpoint source nitrogen pollution of the study area.Results indicated that loss of nitrogen was mainly via the soluble form.TN and DTN changed rapidly throughout the year.Generally,they were highest in December,followed in April,and lowest in September.The range of TN concentration was 0.09~1.359mg/L,indicating that Le′an River was reaching to mediumeutrophication situation.The average concentration of NO3－N was 65% of DTN.NO3－N was the major form of DTN loss and had similar spatial and temporal distribution with TN.The average concentration of NH3－N was the highest among the forms of nitrogen in September.NO2－N concentration was the lowest throughout the year.The research area was divided into two districts according to the physiognomy and the terrain:the northeast low mountains and the southwest hilly area.Various forms of nitrogen concentration in southwestern part were generally higher than those in the northeastern,and the water quality of the upstream was generally better than the downstream

Waterlevel fluctuation zone is the critical area which influences ecological services of reservior.Restoration of natural herbaceous vegetation in the gentle slope waterlevel fluctuation zone in the Three Gorges Reservior was investigated by ecological methods.The main plant types in study area were annual herbs and perennial herbs.There were 29 species of herbaceous plants,among which,Alternanthera philoxeroidesMart.)Girseb.,Cynodon dactylonLinn.)Pers.,Xanthium sibiricum Patrin.,Echinochloa crusgalliL.)Beauv,Setaria viridisL.)Beauv.,Bidens bipinnata L.and Digitaria sanguinalisLinn.)Scop.were the dominant.Alternanthera philoxeroides (Mart.) Girseb. and Cynodon dactylonLinn.)Pers. were constructive species.Plant communities in waterlevel fluctuation zone were all patchiness.There were roughly four plant distribution zones,ie,Alternanthera philoxeroidesMart.) Girseb. and Cynodon dactylon(Linn.) Pers zone,Echinochloa crusgalli(L.)Beauv zone,Xanthium sibiricumPatrin.and Digitaria sanguinalis(Linn.) Scop Setaria viridis(L.)Beauv.zone.Annual weeds zone were from 145 m to 175 m altitude. Plant communities in waterlevel fluctuation zone could restore after flooding in the absence of human intervention, but the  community structure tended to be simple and species diversity decreased significantly.Species diversity,the biomass and coverage along with waterleverl zone first increased,then decreased,and showed a singlepeak pattern,ie,the lower part

In this experiment,pH ranges (7 and 9) were carefully controlled to distinguish the effect of the unionised NH3 and the NH+4 ion.The objective was to find the effect of total ammonia nitrogen concentration and pH on growth of Ceratophyllum demersumThe results showed that relative growth rates (RGR) varied between -010 and 003 per day.The toxicity of total ammonia to C.demersum was a result of the effect of both ionised and unionised forms at low NH3 concentrations (<0.22 mg/L).Relative growth rates of C.demersum decreased linearly with increasing NH3 concentrations up to a maximum level (4.39 mg/L),above which C.demersum died.As the time of ammonia stress prolonged and ammonia content increased,these ammonia additions decreased carbontonitrogen ratios and Chlorophyll contents of C.demersum.At the same time,these ammonia additions weakened photosynthesis and decreased relative growth rate of C.demersumAccording to the test results，the scientific basis can be taken to improve water quality by using C.demersumAnd the result also can provide reference for studying the living condition of submersed macrophytes under the stress of the unionised NH3.

The artificial alder and cypress fixed forest has been massively afforested since 1970s and there has been an obvious land use change in Hilly Area of Central Sichuan Basin.Based on the estimation of biomass and NPP of the artificial alder and cypress fixed forest during different growing periods,organic carbon content of every organ of main trees of the fixed forest，yearly organic carbon store and organic carbon density of the artificial alder and cypress fixed forest during different growing periods were respectively analyzed.Then yearly organic carbon store and organic carbon density of the artificial alder and cypress fixed forest were compared to that of agricultural vegetation during the corresponding period.The result showed that during earlier stage the artificial alder and cypress fixed forest yearly stored a small quantity organic carbon.When the age of the artificial alder and cypress fixed forest was nearly 7 or 8 years old,its yearly organic carbon store was equal to that of paddy rice and dryland.With the age increase of the fixed forest,vegetation organic carbon density of artificial alder and cypress fixed forest increased quickly,and the effect of carbon sink of the forest became more and more obvious. When the age of the artificial alder and cypress fixed forest was bigger than 3 or 4 years old,its organic carbon density was bigger than that of paddy rice and dryland. When the forest was mature (more than 20 years old),its organic carbon density was more than 5 times of that of the corresponding period of farmland.In order to improve ecoenvironment and reduce carbon emission,these countermeasures should be taken into account:enhancing protection,prevention and control of plant diseases and elimination of pests of the artificial alder and cypress fixed forest;engaging in saving management of forest and wood;and actively studying and exploring the transform and rational utilization of the artificial alder and cypress fixed forest.

At present, it is becoming the mainstream to develop largescale livestock farms in China.However,largescale livestock farms not only make great economic benefits,but also cause heavy environment pollution.Then,it is a key problem whether there is an optimal scale for livestock farms from the view of the pollution controlling. Based on the N/P capacity of the farmland,transport cost,pollution charge and other variables,a mathematical model was built to analyze the optimal scale of a livestock farm that would maximize its profit.When the livestock farms chose the scale as the control variable,the optimal scale would increase with the price of the livestock and the N/P capacity of the farmland, and would decrease with the increase of the sum of the directive production cost and manure treat cost,the N/P surplus after the treatment,transport cost,pollution charge.When the livestock farms chose the proportion of the N/P surplus emitted directly as the control variable,the optimal proportion of the N/P surplus emitted directly would decrease with the increase of the pollution charge.Finally,it was concluded that the limit on the scale of livestock farm would be an option to control the livestock pollution when the N/P could not be removed effectively by current technologies，and it was difficult to supervise the livestock whether to treat the N/P surplus properly

Based on the data of arable land in 13 municipal cities in Jiangsu Province from 1998 to 2008,this paper analyzed the change process of arable land and spatial difference nearly 10 years,test the spatial autocorrelation of arable land by the Moran I index,and studied the driving mechanism in the change of arable land by adopting spatial econometric model.From 1998 to 2008,the area of arable land decreased 2969 × 104 hm2 with yearly decrease of 270 × 104 hm2.There was an obvious spatial difference in the change of arable land.The most serious regions of the reduction of arable land included Wuxi,Suzhou,Changzhou,Nanjing and Zhenjiang city.There existed an obvious spatial correlation of the distribution of arable land in Jiangsu Province.Its value of Moran I increased from 04003 to 04524 from 1998 to 2008，and this correlation was growing stronger.The population,economic growth and the ratio of grain and economic crops were the main driving factors and their elastic coefficients were -0803, -0070 and 0069,respectively.There was an obvious significant spatial diffusion effect in the change of arable land in various factors in adjacent areas,and the elastic coefficient was 0779.Therefore,we should take the spatial correlation into consideration in the future to promote the formation of transregional arable land protection mechanism,and establish an integrative regional protection policy

The growth and photosynthetic characteristics of two kinds of super hybrid rice,early rice Zhuliangyou 819 and late rice Fengyuanyou 299,were studied respectively with Jinyou 402 and Huanghuazhan as CK.Zhuliangyou 819 had less tillers than the CK,but its higher percentage of productive tillers led to more panicles.It had higher leaf area index and biomass accumulation rate in the early stage but lower in the latter stage compared with the CK.In the whole growth period,there was no significant difference in photosynthetic rate between Zhulianyou 819 and the CK,and at filling stage,there was no significant difference in all chlorophyll fluorescence parameters either.Fengyuanyou 299 had less tillers and productive tillers than the CK,but it had higher biomass because it maintained an obvious advantage in leaf area index,and its photosynthetic rate was significantly higher than that of the CK at the middle and late stages of growth.At filling stage,there was no significant difference in initial fluorescence (Fo),maximal fluorescence (Fm) and maximum quantum yield of PSII (Fv/Fm), but Fengyuanyou 299 was higher than the CK in the parameters including instantaneous fluorescence (Ft),maxim fluorescence at actinic light (Fm′),effective quantum yield of PS II (Fv′/Fm′), apparent photosynthetic electron transport rate (ETR), photochemical quenching coefficient (qP) and nonphotochemical quenching coefficient (NPQ).Both Zhuliangyou 819 and Fengyuanyou 299 showed high yield characteristics,with the yield being 1629% and 544% respectively higher than that of the CK, but the reasons differed. Zhuliangyou 819’s high yield lied in its higher biomass accumulation at early stage and higher photosynthetic transport efficiency, while Fengyuanyou 299’s high yield lied in its higher photosynthetic capacity at the middle and late stages and higher harvest index.