Drivers of spatial structure in thinned forests

Background:As is widely known,an increasing number of forest areas were managed to preserve and enhance the health of forest ecosystems.However,previous research on forest management has often overlooked the importance of structure-based.Aims:Our objectives were to define the direction of structure-based forest management.Subsequently,we investigated the relationships between forest structure and the regeneration,growth,and mortality of trees under different thinning treatments.Ultimately,the drivers of forest structural change were explored.Methods:On the basis of 92 sites selected from northeastern China,with different recovery time (from 1 to 15years) and different thinning intensities (0–59.9%) since the last thinning.Principal component analysis (PCA)identified relationships among factors determining forest spatial structure.The structural equation model (SEM)was used to analyze the driving factors behind the changes in forest spatial structure after thinning.Results:Light thinning (0–20%trees removed) promoted forest regeneration,and heavy thinning (over 35% of trees removed) facilitated forest growth.However,only moderate thinning (20%–35%trees removed) created a reasonable spatial structure.While dead trees were clustered,and they were hardly affected by thinning intensity.Additionally,thinning intensity,recovery time,and altitude indirectly improve the spatial structure of the forest by influencing diameter at breast height (DBH) and canopy area.Conclusion:Creating larger DBH and canopy area through thinning will promote the formation of complex forest structures,which cultivates healthy and stable forests.

The multiple roles of crop structural change in productivity,nutrition and environment in China:A decomposition analysis

China's crop structure has undergone significant changes in the last two decades since 2000,with an increase in the share of cereals,vegetables,and fruit,squeezing out other crops.As a result,land productivity,nutrient supply,and carbon emissions have changed.How to reallocate limited farmland among crops to achieve the multiple goals of agrifood systems becomes an important issue.This study explores the sources of land productivity and nutrition supply growth and carbon emissions reduction,and identifies the multiple roles of crop structural change from 2003 to 2020 based on a decomposition analysis.The results reveal that the growth within crops is still the primary driver in land productivity and nutrition supply and the reduction in carbon emissions.However,structural change also plays various roles at different periods.From 2003 to 2010,crop structural change increased the total calorie supply but lowered land productivity and contributed at least 70%of the total growth of carbon emissions.The crop structure was relatively stable,and their effects were modest from 2010 to 2015.From 2015 to 2020,the crop structural change began to play a greater role and generate synergistic effects in improving land productivity,micronutrient supply,and reducing carbon emissions,contributing to approximately a quarter of the growth of land productivity and 30%of total carbon emissions reduction.These results suggest that strategies for crop structural change should comprehensively consider its multiple impacts,aiming to achieve co-benefits while minimizing trade-offs.

Changes of growth-climate relationships of Smith fir forests along an altitudinal gradient

Temporal changes in the relationship between tree growth and climate have been observed in numerous forests across the world.The patterns and the possible regu-lators(e.g.,forest community structure)of such changes are,however,not well understood.A vegetation survey and analyses of growth-climate relationships for Abies georgei var.Smithii(Smith fir)forests were carried along an altitudi-nal gradient from 3600 to 4200 m on Meili Snow Mountain,southeastern Tibetan Plateau.The results showed that the associations between growth and temperature have declined since the 1970s over the whole transect,while response to standardized precipitation-evapotranspiration indices(SPEI)strengthened in the mid-and lower-transect.Comparison between growth and vegetation data showed that tree growth was more sensitive to drought in stands with higher species richness and greater shrub cover.Drought stress on growth may be increased by heavy competition from shrub and herb layers.These results show the non-stationary nature of tree growth-climate associations and the linkage to for-est community structures.Vegetation components should be considered in future modeling and forecasting of forest dynamics in relation to climate changes.

Characteristics and drivers of the soil multifunctionality under different land use and land cover types in the drylands of China

The drylands of China cover approximately 6.6×106 km2 and are home to approximately 5.8×10^(8)people,providing important ecosystem services for human survival and development.However,dryland ecosystems are extremely fragile and sensitive to external environmental changes.Land use and land cover(LULC)changes significantly impact soil structure and function,thus affecting the soil multifunctionality(SMF).However,the effect of LULC changes on the SMF in the drylands of China has rarely been reported.In this study,we investigated the characteristics of the SMF changes based on soil data in the 1980s from the National Tibetan Plateau Data Center.We explored the drivers of the SMF changes under different LULC types(including forest,grassland,shrubland,and desert)and used structural equation modeling to explore the main driver of the SMF changes.The results showed that the SMF under the four LULC types decreased in the following descending order:forest,grassland,shrubland,and desert.The main driver of the SMF changes under different LULC types was mean annual temperature(MAT).In addition to MAT,pH in forest,soil moisture(SM)and soil biodiversity index in grassland,SM in shrubland,and aridity index in desert are crucial factors for the SMF changes.Therefore,the SMF in the drylands of China is regulated mainly by MAT and pH,and comprehensive assessments of the SMF in drylands need to be performed regarding LULC changes.The results are beneficial for evaluating the SMF among different LULC types and predicting the SMF under global climate change.

The Study on Industrial Structure Adjustment of Farmer Economic Net Income Doubled in Mountain Area

The aim was to study the main industry effect the double of the per capi- ta net income of farmers economic. The relation between six industry net income per capita income of farmers including grain, animal husbandry, flue-cured tobacco, walnut, long-term labor expot, seasonal labor export and the net income of farmers per capita in the Wazitian Village of Baoshan, Yunnan was studied by means of the effect main industry doubled net income of farmers per capita economic and the grey correlation analysis. The correlation degree of six industry and the net income of farmers per capita economic was long-term labor export〉seasonal labor export〉 walnut〉grain〉animal husbandry〉flue-cured tobacco. The pillar industry affecting the net income of farmers per capita economic was long-term labor export, seasonal la- bor export and walnut. The study provided the scionce theoretical basis and method of support for net income per capita economic multiplier of farmers in Baoshan, Yunnan province and even a similar low latitude mountain plateau.

The Impact of Changes of the Internal Agricultural Structure in Sichuan Province on Farmers' Income

After introducing the status quo of farmers' net income and gross output value of agriculture of Sichuan Province,and the changes of agricultural output structure,the regression analysis was conducted on the impact of the changes in agricultural structure on the farmers' net income per capita on the strengthen of the data from Sichuan statistical yearbook and by the way of econometrics.The multiple linear regression analysis was conducted on the impact the changes in crop farming on farmers' net income by using logarithmic demand model.The results show that the agricultural structure has transformed from the dominant crop farming to the all-around developmental trend covering the dominant industry,animal husbandry and forestry,fishery and the other industries;the animal husbandry has greatest impact on famers' income per capita and the impact of crop farming is slightly weaker than animal husbandry;the crop farming and animal husbandry develop fairly rapid simultaneously and the two all have great impact in farmers' income;among animal husbandry,the meat and eggs have relatively great impact on farmers' income,while in crop farming,grain plays the dominant role in affecting farmers' income,followed by cash crop.Hence,the relevant countermeasures applied to increase farmers' income are put forward in terms of optimizing the internal structure of agriculture,adjusting the internal structure of crop farming,adjusting the internal structure of animal husbandry and strengthening the support of farmers.

Microwave Drying of Scots Pine Lumber:Structure Changes,Its Effect on Liquid Permeability

Microwave(MW)drying method was adopted to enhance the liquid permeability of Scots pine lumber.Structure changes were characterized by stereoscope microscope,scanned electron microscope(SEM)and transmission electron microscope(TEM)examination.Pore parameters before and after MW treatment were detected by mercury intrusion porosimetry(MIP)method,and the effect of structure changes on liquid permeability were analyzed.As stereoscope microscope,SEM and TEM examination results showed,macro and micro checks mainly developed at intercellcular of tracheids,intercellular of ray parenchyma and tracheid,while these checks extend main along the radial-longitudinal plane.Pit border destruction,aspirated pits’orus translocation and micro-checks in tracheid cell wall were also observed.MIP test shown that pore volume and pore area increased as macro and micro checks generated to form new cavities.Microstructure changes would increase the quantity of pores or enlarge the pore diameter.Liquid flow pathways increased as macro and micro checks generated,aspirated pits reopened to form new pathways;liquid flow efficiency improved as porosity,pore volume and pore diameter increased which facilitated the liquid flow.

Overview of the Reports on the Reformation of Personal Income Taxation

Presentation of the reports on the reformation of personal income taxation that have been prepared with a development plan for the Greek economy,that discuss the issue of taxation and point out its important features.The goal is the complete modernization of the tax system,so that it responds more fully to the principles of social justice,contributes to the economic development of the country and is governed by simple and modern procedures,which apply to all tax objects.The purpose of the study is to deepen the proposals for tax reform based on the peculiarities of the Greek economy,the international trends in this field and the weaknesses of the tax system.The effects of a tax reformation are analyzed and how it should take the form of the reform,which,however,requires a new legislation,which will bring about radical and deep cuts,which respond to the new conditions and the internationalization of the economy.Proposals for a set of structural measures,which are necessary for the country’s adaptation to the wider European environment and the elimination of the weaknesses that increase its distance from the other member countries.Citation of the common points of the reports on the reformation of personal income taxation and their adoption by the tax leadership.

The Role of Income Structure Improvement in Helping Broaden the Rural Consumer Market

Too large urban-rural gap and weak rural consumption is the most significant problem in rural areas,and also an insurmountable barrier to the process of China's economic development.At the same time,the modernization of agriculture is proposed as the major policy for China to actively solve issues concerning agriculture,countryside and farmers.Using panel data model and taking into account the regional characteristics and time effects of the sample data,we conduct analysis of the farmers'income structure in the five provinces and one city of East China at the upper reaches of economy,and estimate the effects of farmers'income on farmers'consumer spending,in order to find the main channel for improving farmers'consumption.This paper emphasizes the great significance of farmers'consumption improvement to China's economic restructuring and solving the future economic development in the context of current financial crisis.

Why Does China＇s Labor Income Share Tend to Decline？- From the Perspective of Population Age Structure Change

Using a theoretical model, this article concludes that age structures influence people＇s propensity to save and thereby influence their capital intensity. In the context that capital and labor are in a substitutional relation, increased capital intensity may lead to a drop of labor income share. We perform empirical research with provincial-level data from 1990 to 2007 and have proved that the rising of the old dependency ratio and the decrease of the children dependency rate both contribute to the fall of labor income share. This assumption still holds true after the authors control the influences of other potential factors that may influence labor income share

Analysis of Income Structure of Farmer (Herdsman) of the Tibet Autonomous Region

Based on the sampling data this paper analyzes income structure of farmer (herdsman) of the Tibet Autonomous Region, including source, characteristics and cash. Situation of income structures and income sources of the farmers in different areas (agricultural, animal husbandry areas and half agricultural and half animal husbandry areas etc. ) was approached. The following features were found through an analysis of surveyed data: (1) In Tibetan peasant household goods and products instead of money. disposable income and cash are very little. (2) The variety index of income is higher in the out skirt than it in rural, the index has a direct bearing on net income. (3) The income ways are simplistic and out-date in the poor households, they have no ability to resist and guard a-gainst any risk, it is very difficult to increase their receipts. (4) The living standard in agricultural areas is better than in pastoral areas, it is the worst in half agriculture and half animal husbandry areas.

The Path Analysis of Farmers' Income Structure in Yunnan Province

The problem of farmers' income growth is the key of issues concerning agriculture,countryside and farmers,so the farmers' income growth is the fundamental starting point for agricultural and rural economic development. In this paper,we use the statistics concerning farmers' income in Yunnan Province from 1995 to 2012,to perform the path analysis of components of farmers' income in Yunnan Province,study the path of influence of components of farmers' income on farmers' net income,and then set forth the policy recommendations for increasing farmers' income in Yunnan Province.

Simulation and Analysis of Land System Structure Changes in Huang-Huai-Hai Plain Area

The dynamic changes of land system in Huang - Huai - Hai Plain between 1988 and 2000 were researched in this paper. Spatial dominance econometric model was estabilished on 1 km cell to quantificafionally analyze the driving-force for the dynamic change mechanism of land system, such as natural, social and economic factors. The future dynamic changes of land system in Huang - Huai - Hai Plain on each 1 km cell during 2000 to 2020 were stimulated by combining the dynamic changes of land system on each 1 km cell with different situations. The research indicated that the dynamic changes of land system structure changed mainly from the cultivated areas to building areas and industrial areas, and forest areas increased during this period. Although the revolutions of land system structure were different during 2000 to 2020 with the different referrence standard, ecological protection and economic development, the primary dynamic changes of land system structure were that the increase of building land areas with the decline cuhivaled land areas and the increase of woodlands.

Structure and seasonal changes in atmospheric boundary layer on coast of the east Antarctic continent

The temperature, humidity, and vertical distribution of ozone in the Antarctic atmospheric boundary layer（ABL） and their seasonal changes are analyzed, by using the high-resolution profile data obtained during the International Polar Year 2008 to 2009 at Zhongshan Station, to further the understanding of the structure and processes of the ABL. The results show that the fre- quency of the convective boundary layer in the warm season accounts for 84% of its annual occurrence frequency. The frequency of the stable boundary layer in the cold season accounts for 71% of its annual occurrence frequency. A neutral boundary layer ap- pears rarely. The average altitude of the convective boundary layer determined by the parcel method is 600 m; this is 200 to 300 m higher than that over inland Antarctica. The average altitude of the top of the boundary layer determined by the potential tempera- ture gradient and humidity gradient is 1 200 m in the warm season and 1 500 m in the cold season. The vertical structures of ozone and specific humidity in the ABL exhibit obvious seasonal changes. The specific humidity is very high with greater vertical gradi- ent in the warm season and very low with a lesser gradient in the cold season under 2 000 m. The atmospheric ozone in the ABL is consumed by photochemical processes in the warm season, which results in a slight difference in altitude. The sub-highest ozone center is located in the boundary layer, indicating that the ozone transferred from the stratosphere to the troposphere reaches the low boundary layer during October and November in Antarctica.

Empirical Analysis of Relationship between Farmers'Income Structure and Consumption in Guizhou Province in the Context of Large-scale Poverty Alleviation

Large-scale poverty alleviation is one of the three major strategic actions of Guizhou Province to plan for leapfrog development.Through building an econometric model,this paper made an empirical analysis of relationship between farmers'income structure and consumption in Guizhou Province in the context of large-scale poverty alleviation.The results show that the wage income and transfer income of rural residents in Guizhou Province have a significant impact on the promotion of their consumption,and the impact of income from household business operation is also significant,but the impact is relatively weak,while the contribution of farmers'property income to their consumption is insufficient.Finally,in view of the problems in the relationship between the income structure and consumption of farmers in Guizhou Province,it came up with policy recommendations including broadening the income channels,increasing farmers'income,improving the income structure,and promoting farmers'consumption.

The Influence of the Urban-Rural Income Disparity on the Industrial Structure—Taking the Yangtze River Delta Region as an Example

In this paper, the effect of the mediation effect is mainly used to test and analyze the regression model, and most scholars have studied the impact of the modernization of the industrial structure on the income gap. However, this paper is from another perspective, based on the social background of high-quality development, the main study is the impact mechanism of urban and rural income gap on the industrial structure, taking the Yangtze River Delta as the main research object, and specifically selecting 22 central cities in the Yangtze River Delta region, which is also one of the highlights of this study. The regression model is constructed by using the intermediary effect, and the four intermediary variables of fiscal expenditure (M1), fixed asset investment (M2), number of patent applications (M3), and total import and export (M4) are selected, which represent the role of the government, fixed asset investment, scientific and technological level and opening-up level, and study and analyze the inherent influence mechanism between each variable. Before doing specific research, I consulted the papers and literature of many other outstanding scholars, among which Cheng Yuhong and Cheng Chi’s “The Influence Mechanism of industrial structure of urban and rural income gap” [1] has great reference value for this paper. According to the research results, under the background of high-quality development in the Yangtze River Delta region, the expansion of the income gap between urban and rural areas will inhibit the upgrading of the industrial structure, so it is necessary to focus on building a new type of urbanization, accelerating the construction of an urban innovation system, optimizing the rural employment structure to narrow the income gap between urban and rural areas, and providing impetus for the continuous upgrading of the industrial structure.

The Influences of Population Age Structure＇s Changes on the Export Commodity Structure

For a long time, China has large population, so the labor-intensive products become the comparative advantage.This paper analyzes the influences of population age structure＇s changes on the export commodity structure of our country and draws conclusions.

The Impact of the Upgrading of Industrial Structure in the Yangtze River Delta on the Urban-Rural Income Gap

Firstly,this paper conducts theoretical analysis and current situation analysis,and then proposes research hypotheses.Secondly,using spatial Dubin model and partial differential method,it empirically studies the impact of industrial structure advancement and rationalization on the urban-rural income gap.The results show that:(1)Both industrial structure and urban-rural income gap have significant spatial dependence;(2)The increase in the industrial structure rationalization will narrow the urban-rural income gap in local region,while its spillover effect on neighboring areas is not obvious.(3)The impact of the industrial structure advancement on the urban-rural income gap is not linear.It is first expanded and then narrowed.The industrial structure advancement in the Yangtze River Delta will generally narrow the urban-rural income gap at this stage.Finally,this paper put forward relevant suggestions.

Simulation Research on Structure Changing Control over the Follow Up System of the Smart Mine

By analyzing the target's motion pattern, in terms of the requirement for the performance indexes of the follow up system, the structure changing control and time optimal theory is proposed. The system's control scheme from three different aspects(the dynamic response simulation, compound control simulation and dynamic tracking simulation) is also studied. And all the results proved the feasibility of the synthetical utilization of the open loop control, speed decreased control and position closed loop control.