Study on the Variation of Ningxia Climate Productive Potential under the Returning Farmland to Forestland and Grassland Background

The key zones of returning farmland to forestland and grassland in Ningxia were studied. By using the ＂stepwise revised method＂,the climate productive potential,light and temperature productive potential in the zone in recent 50 years were counted. The light and temperature productive potential of corn in Ningxia irrigated area,the central arid zone and the southern mountain area presented the linear increase trend. But when considered the climate productive potentials of light,temperature and water,the numerical value was very low because of the scarce rainfall,and no agriculture without the irrigation. The light and temperature productive potential,climate productive potential of winter wheat in the central arid zone had no significant trend,but the variation range of climate productive potential was very big. The light and temperature productive potential of winter wheat in the southern mountain area had no significant variation trend,and the climate productive potential presented the weak decline trend. It illustrated that the productive of winter wheat was greatly restricted by the water content. By using the meteorological factor data which were simulated by RegCM3-WOFOST/LINGRA coupled model,the future climate productive potentials of winter wheat in the central south of Ningxia was counted. They both presented the weak increase trend. It illustrated that the climate in Ningxia was favorable to improve the yield of winter wheat after returning farmland to forestland.

Inconsistent increasing of climate potential productivity resulting from global warming and land use transitions in the Dongting Lake Basin,from 2000 to 2020

In the face of global warming and increasing impervious surfaces,quantifying the change of climate potential productivity(CPP)is of great significance for the food production planning.Targeting the Dongting Lake Basin,which is a key area for food production in China,this paper uses meteorological data,as well as Climate Change Initiative Land Cover,and Shuttle Radar Topography Mission digital elevation model to investigate the CPP and its changes from 2000 to 2020.The suitability of land for cultivation(SLC),and the land use/land cover change(LUCC)are also considered.The results showed that the CPP varied from 9,825 to 20,895 kg ha^(-1).Even though the newly added impervious surfaces indirectly resulted in the decrease of CPP by of 9.81×10~8 kg,overall,the CPP increased at an average rate of 83.7 kg ha^(-1)a^(-1).Global warming is the strongest driver behind CPP increase,and CPP has played an important role in the conversions between cultivated land and other land types.The structure of land types tends to be optimized against this challenge.

Analysis of the Identification of Local Agriculture Products in the Municipality of Aileu, Manufahi, and Ainaro That Have Potential for Export and Attract Foreign Investments in Agricultural Sector

The objective of this study is to identify and collect information on local agriculture products and identify local potential agriculture and livestock that can attract foreign investments. Used Stratified Random Sampling and data was collected from both primary and secondary data (both quantitative and qualitative data. The data analyzed used qualitative and quantitative analysis. The supply chain analysis was carried out to develop a description of the value chain to identify potential high-value market areas and current and potential products in the domestic and export markets. The results of the study revealed that most farmers in the research location grow different types of crops and livestock. In particular for Aileu and Ainaro where most of the areas are up-land, therefore, horticulture crops (mustard, cabbage, carrots, and tomato) and coffee are dominated in these areas. For Manufahi, some parts are lowland areas, where most crops grown are maize, cassava, and paddy rice. The study reveals that local potential agriculture products and livestock in the municipalities of Aileu, Ainaro, and Manufahi are vegetable, coffee, maize, and paddy rice, banana, shallot, tangerine, cabbage, carrot, cattle, mung-bean, and banana. To accelerate economic growth, in these municipalities, there is a need to modernize agricultural production, requiring markets for both inputs supply and for the sale of output products. Opportunities to increase the productivity of these products are feasible and this can be done through the use of high-variety seeds and better farm management, and the government and private sector can play an important role in improving productivity as this will have a further implication in improving food security.

Evaluation on Solar Radiation Resource and Photosynthetic and Thermal Potential Productivity in Shandong Province

To evaluate scientifically the change of photosynthetic and thermal potential productivity caused by climate variation,based on comparison with mean of previous 30 years(1971-2000),the change of total solar radiation,sunshine hours,photosynthetic active radiation,photosynthetic and thermal potential productivity since 2001 were analyzed through data of radiation,sunshine and temperature in Shandong Province from 1971 to 2007,and the change trend was also tested by Mann-Kendall non-parametric statistical met...

Evaluation of Potential Fishery Productivity in Lihu Lake Based on GIS

[Objective] The paper was scientifically evaluate the potential fishery productivity of Lihu using GIS technology.[Method] The evaluation of potential fishery productivity in Lihu was based on GIS and AHP according to the characteristics of fisheries resources in Lihu Lake.The evaluation system included 3 sub-models including water quality,biodiversity and hydrological condition,which totally had 10 indexes.Judgment matrix was constructed based the advices of professors of fisheries resources,and the indicator’s weight were calculated by the process of AHP.The ranking distributing map of potential fishery productivity in Lihu was obtained by the model of raster analysis,raster calculator,spatial overlay and classification models of ARC/INFO.[Result] Potential fishery productivity of Lihu was divided into 4 grades in term of higher,high,general and low,and which covered 2.643 3,3.844 8,1.121 4 and 0.400 5 hm2,respectively.[Conclusion] The study provided theoretical basis for ecological reconstruction of Lihu Lake.

Research on the Dynamic Climatic Production Potential of Middle-season Rice in Jiangxi Province

According to the meteorological data from Meteorological Station during 1961-2007 in Jiangxi Province,using the calculation method of production potential of climate recommended by Food and Agriculture Organization(FAO),the variation trends of climatic potential productivity of mid-season rice during this period were analyzed.The results indicated a trend of yearly decline in the variation of photosynthetic and light-temperature potential productivity in Jiangxi.The changes of climatic production potential fluctuated widely.The main reasons for the above-mentioned changes in recent years included more serious air pollution,resulting in less light and decline in photosynthetic potential productivity.An increase in extreme high-temperature days inhibited the growth of mid-season rice.The uneven distribution of precipitation resulted in the volatility of climatic production potential.To ensure high and stable yield,some counter-measures should be taken,including increasing weather modification input,building water conservancy facilities,enhancing the accuracy of weather forecasts and strengthening the research on climate changes.All the methods could solve those problems so as to ensure an improvement in rice production capacity to address climate change.

Calculation of forest potential productivity for Tianshan forest region

Forest Potential Productivity (FPP) of 8 counties in Tianshan was cal culated, and the potential timber output of these counties was analyzed with Mia mi Model and Thornthwaite Memorial Model. Research results showed that annual av erage output of present stand in Tianshan Forest Region was 3.7 m3/(hm2. a), whi ch reached only 49% of average FPP.

Climate Characteristics in Three Gorges Reservoir Area after Water Storage and Its Impact on the Production Potential

Based on the meteorological data from 33 stations of Three Gorges Reservoir from 1960 to 2008,climate yield of rice,corn and winter wheat and the changes of climatic potential productivity after water storage in Three Gorges Reservoir were calculated by the dynamic statistic model of crop growth.The results showed that the temperature in Three Gorges Reservoir was fluctuant decreased before late 1980s,and warmed rapidly after the late 1980s.The precipitation had little change before the late 1990s and had a slight decrease after the late 1990s.Sunshine hours were more in 1960s and 1970s,and then it changed little after 1980s.After water storage,the temperature increased in Three Gorges Reservoir as a whole.The precipitation decreased in the south of Three Gorges Reservoir,while it increased in the northwest of Three Gorges Reservoir.The sunshine hours were reduced except that in the vicinity of Dianjiang.After water storage,climatic potential productivity of rice decreased in the northwest and the northeast,while it increased in the south of Three Gorges Reservoir.The climatic potential productivity of corn decreased in the northeast and the southwest,but increased in the rest of Three Gorges Reservoir.The climatic potential productivity of winter wheat increased almost in total.

Quantifying the spatial variation in the potential productivity and yield gap of winter wheat in China

Despite the improvement in cultivar characters and management practices, large gaps between the attainable and potential yields still exist in winter wheat of China. Quantifying the crop potential yield is essential for estimating the food production capacity and improving agricultural policies to ensure food security. Gradually descending models and geographic infor- mation system （GIS） technology were employed to characterize the spatial variability of potential yields and yield gaps in winter wheat across the main production region of China. The results showed that during 2000-2010, the average potential yield limited by thermal resource （YGT） was 23.2 Mg ha-1, with larger value in the northern area relative to the southern area. The potential yield limited by the water supply （YGw） generally decreased from north to south, with an average value of 1.9 Mg ha-1 across the entire study region. The highest YGw in the north sub-region （NS） implied that the irrigation and drainage conditions in this sub-region must be improved. The averaged yield loss of winter wheat from nutrient deficiency （YGH） varied between 2.1 and 3.1 Mg ha-1 in the study area, which was greater than the yield loss caused by water limitation. The potential decrease in yield from photo-thermal-water-nutrient-limited production to actual yield （YGo） was over 6.0 Mg ha-1, ranging from 4.9 to 8.3 Mg ha^-1 across the entire study region, and it was more obvious in the southern area than in the northern area. These findings suggest that across the main winter wheat production region, the highest yield gap was induced by thermal resources, followed by other factors, such as the level of farming technology, social policy and economic feasibility. Furthermore, there are opportunities to narrow the yield gaps by making full use of climatic resources and developing a reasonable production plan for winter wheat crops. Thus, meeting the challenges of food security and sustainability in the coming decades is possible but will require considerable changes in water and nutrient management and socio-economic policies.

Effect of Cropland Occupation and Supplement on Light-temperature Potential Productivity in China from 2000 to 2008

There are more people but less land in China,so food safety has always been a most important issue government concerned.With continuous population increase,economic development and environment protection,cropland occupation and supplement are unavoidable.It not only leads to the variation of cropland area,but also makes the light-temperature potential productivity per unit area different due to regional climate differentiation,therefore impacts the total potential productivity and food output eventually.So,it is necessary to analyze the climate differentiation between occupation and supplement cropland areas and to study its impact on total potential productivity,which is significant to reasonably develop natural resources and instruct agricultural arrangement.This study firstly discussed the variation and distribution of occupation and supplement croplands in China from 2000 to 2008,then analyzed the climate differentiation between occupation and supplement cropland areas and its effect on light-temperature potential productivity.The results demonstrate:1) From 2000 to 2008,the cropland variation presented occupation in the south and supplement in the north,but overall decreased.Supplement cropland was mainly from ecological reclamation(77.78%) and was mainly distributed in Northeast China and Northwest China with poor climatic and natural conditions.Occupation cropland was mainly used for construction(52.88%) and ecological restoration(44.78%) purposes,and was mainly distributed in the Huang-Huai-Hai Plain,and the middle and lower reaches of the Changjiang(Yangtze) River with better climatic and natural conditions.2) The climate conditions were quite different in supplement and occupation cropland areas.The annual precipitation,annual accumulated temperature and average annual temperature were lower in the supplement cropland area,and its average po-tential productivity per unit was only 62% of occupation cropland area,which was the main reason for the decrease of total potential productivity.3) Cropland occupation and supplement led to the variation of total potential productivity and its spatial distribution.The productivity decreased in the south and increased in the north,but had a net loss of 4.38315×107 t in the whole country.The increase of cropland area was at the cost of reclaiming natural forest and grassland resources,and destroying natural ecological environment,while the decrease of cropland area was mainly due to a lot of cropland occupied by urban-rural construction,which threatened the sustainable use of cropland resources.

China’s Potential of Grain Production Due to Changes in Agricultural Land Utilization in Recent Years

The changes in utilization of agricultural land have gradually grown into one of the major factors impacting grain output in China. This study explores the various components of agricultural production in China from the land utilization perspective, involving changes in grain production per unit area, multi-cropping index, and adjustment of agricultural structure. Compared with the record values, different research methodologies are used to analyze the po- tential of above three components. The results indicate that grain production potential of 65.68×109kg was unexploited in 2006, in which 45.8×109kg came from the restructuring in agriculture. So we can infer that the reduction of grain production in China could be primarily attributed to agricultural restructuring in recent years. So the productive poten- tial can be fully restored by increasing agricultural investment, or recovering agricultural structure in favorable condi- tions. So we can say that China’s current condition of food security is good.

Geological Controls on the CBM Productivity of No.15 Coal Seam of Carboniferous–Permian Taiyuan Formation in Southern Qinshui Basin and Prediction for CBM High-yield Potential Regions

Coalbed methane(CBM) resources in No.15 coal seam of Taiyuan Formation account for 55% of the total CBM resources in southern Qinshui Basin(SQB), and have a great production potential. This study aims at investigating the CBM production in No.15 coal seam and its influence factors. Based on a series of laboratory experiments and latest exploration and development data from local coal mines and CBM companies, the spatial characteristics of gas production of No.15 coal seam were analyzed and then the influences of seven factors on the gas productivity of this coal seam were discussed, including coal thickness, burial depth, gas content, ratio of critical desorption pressure to original coal reservoir pressure(RCPOP), porosity, permeability, and hydrogeological condition. The influences of hydrological condition on CBM production were analyzed based on the discussions of four aspects: hydrogeochemistry, roof lithology and its distribution, hydrodynamic field of groundwater, and recharge rate of groundwater. Finally, a three-level analytic hierarchy process(AHP) evaluation model was proposed for predicting the CBM potentials of the No.15 coal seam in the SQB. The best prospective target area for CBM production of the No.15 coal seam is predicted to be in the districts of Panzhuang, Chengzhuang and south of Hudi.

The coalbed methane production potential method for optimization of wells location selection

A gas production potential method for optimization of gas wellsite locations selection is proposed in terms of the coalbed gas resources volume and the recoverability. The method uses the actual data about reservoirs in a coalbed gas field in central China to optimize wellsite locations in the studied area in combination with the dynamic data about actual production in the coalbed gas field, selects a favorable subarea for gas wells deployment. The method is established based on the basic properties of coal reservoirs, in combination with the coalbed thickness and the gas content to make an analysis of the gas storage potential of a coal reservoir, as well as resources volume and the permeability of a coal reservoir. This method can be popularized for optimization of wellsite locations in other methane gas development areas or blocks.

Impact of Climate Variation on the Exploitation Degree of Production Potential of Winter Wheat in Tianshui

The productivity exploitation degree,suitable exploitation degree and exploitable exploitation degree of production potential of winter wheat in three climate zones of Tianshui were calculated.The impacts of climate changes on it were analyzed.The results showed the exploitation degree of production potential of winter wheat was still low in the north of Wei River,the valley of Wei River and the area of Guan Mountain in Tianshui,being 49.9%-60.0%.Both the suitable exploitation degree and exploitable exploitation degree of production potential of winter wheat were comparatively high,being 73.6%-78.7% and 18.7%-23.8% respectively.The sequencing was the north of Wei River>the valley of Wei River>the area of Guan Mountain.In the long run,it was of great potential to be excavated.The average temperature,sunshine hours for growth season of winter wheat had negative effects on exploitation degree,suitable exploitation degree and exploitable degree of production potential of winter wheat.The precipitation had the positive effect.And the temperature in the entire growth period,temperature in autumn,the sunshine in winter had remarkable negative effects on the exploitation degree of the production potential in Tianshui and the north of Wei River.The precipitation in the entire growth period,the precipitation in autumn had remarkable positive effects in Tianshui and each climate zones.And some moderate development countermeasures of regional production potential were proposed.

Simulation of Potential Production and Optimum Population Quantitative Indices for the Second Hybrid Rice

The article established the HDRICE model by modifying the structure of the ORYZA1 model and revising its parameters by field experiments. The HDRICE model consists of the modules of morphological development of rice, daily dry matter accumulation and partitioning, daily CO2 assimilation of the canopy, leaf area, and tiller development. The model preferably simulated the dynamic rice development because of the thorough integration of the effects of temperature and light on the rates of rice development, photosynthesis, respiration, and. other ecophysiological processes. In addition, this model has attainable grain yield in the test experiment that showed the potential yield of cultivar Xieyou 46 ranged from 11 to 13 tons ha-~. Besides, the model was used to optimize the combinations of the transplanting date, seedling age and density for cultivar Xieyou 46 at Jinhua area, and the population quantitative indices to attain the potential yield such as maximum stems, effective panicles, filled grain number/leaf area, and so on. The result showed that the combination of transplanting date on July 25, seedling age of 35 days and base seedling density of 1.33 x 106ha-1 is the optimum combination for the second hybrid rice production in Jinhua County, China. And the maximum stems, the effective panicles, the filled grain per panicle, the peak of optimum LAI, LAI in later filling stage, and the filled grain number/leaf were 6.03×10^6ha, 3.99×10^6ha, 119.2, 8.59, 5-6, and 0.64, respectively.

Impacts of climate change on the potential forest productivity based on a climate-driven biophysical model in northeastern China

Climate warming is expected to influence forest growth,composition and distribution.However,accurately estimating and predicting forest biomass,potential productivity or forest growth is still a challenge for forest managers dealing with land-use at the stand to regional levels.In the present study,we predicted the potential productivity(PP)of forest under current and future climate scenarios(RCP2.6,RCP4.5,RCP6.0 and RCP8.5)in Jilin province,northeastern China by using Paterson’s Climate Vegetation and Productivity(CVP)index model.The PP was validated by comparing it with the mean and maximum net primary production calculated from light energy utilization(GLM_PEM).Our results indicated that using the CVP index model is partially valid for predicting the potential forest productivity in northeastern China.PP exhibited obvious spatial heterogeneity varying from 4.6 to 8.9 m3 ha-1 year-1 with an increasing tendency from northwest to southeast driven by the precipitation across the region.The number of vegetation-active months,precipitation and insolation coefficient were identified as the primary factors affecting PP,but no significant relationship was found for warmest temperature or temperature fluctuation.Under future climate scenarios,PP across the Jilin Province is expected to increase from 1.38%(RCP2.6 in 2050)to 15.30%(RCP8.5 in 2070),especially in the eastern Songnen Plain(SE)for the RCP8.5 scenarios.

Evaluation of Potential Land Productivity in Wulushan, West China

The general situation of the total land resources in Wulushan, West China was studied by field investigations with the aid of a GIS software, called Region Manager. The current status of land use in Wulushan is described. The potential land productivity was evaluated by a fuzzy comprehensive method, We take each plot as a basic unit of evaluation on the basis of an index system of land resources in Wulushan which was developed from the investigation data. Evaluation of potential land productivity is the key part of land management. A guideline is presented in this paper for a proper utilization of the land resources and to develop the productive capacity of the land.

The study of productivity in the Bohai Sea-Ⅱ. Primary productivity and estimation of potential fish catch

-On the basis of the data obtained from the surveys in the Bohai Sea during 1982-1983, this paper analysed and discussed the distribution and seasonal variation of primary productivity in the Bohai Sea, and the correlations between the primary productivity and environmental factors. The organic carbon production and prospect of fishery production in the waters of this sea are estimated. It is shown that, there exists production patential in the Bohai Sea, the primary production is 112 gC/ (m2 ?a)the production of organic carbon being 10 million ton per year, the fishery yields 1 million ton and the maximum catch of sea products 0. 5 million ton. The results of the investigation can serve as the basic data for the exploitation, utilization and management of the fishery resources in the Bohai Sea.

Evaluation of Potential Productivity of Woody Energy Crops on Marginal Land in China

Energy crops are a basic material in the bioenergy industry, and they can also mitigate carbon emissions and have environ- mental 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 × 106 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 × 106 ha, with Xanthoceras sorbifolia and Cerasus humilis mainly grown in the northern China, Jatropha curcas and Comus 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 × 106 t/yr. Without considering the overlapping areas, the potential productivity was 6.81× 106 t/yr from X. sorbifolia, 8.86× 106t/yr from C. humilis, 7.18 ×106t/yr from J. curcas, 9.55 × 106t/yr from P. chinensis, and 7.78 ×106 t/yr from C. wilsoniana.

AN ANALYSIS ON THE INFLUENCE OF GLOBAL CLIMATIC CHANGE UPON NATURAL ZONES AND AGRICULTURAL POTENTIALPRODUCTIVITY IN CHINA

According to climatic, hydrological, soil and vegetation data from671 stations in China, 12 temperate zones contains 45 natural regions areidentified. In this paper, methods like migration of crop distribution , potentialproductivity, and dynamic modelling are used to research changs of naturalzones and natural regions of eco-envirotunent.