Ecological Risks of Agricultural Land Capitalization and Their Prevention

The capitalization of agricultural land as an institutional innovation in land use is of great significance to revitalize China's land resources, change land use and improve land use efficiency. With the gradual implementation of the capitalization of agricultural land, however, environmental problems brought by capitalization have restricted the sustainable and efficient utilization of agricultural land. This study, from the perspective of ecology, discusses ecological risks of agricultural land capitalization, analyzes the ecological risks of agricultural land capitalization in terms of the amount of land and land quality as well as the formation mechanism of the ecological risks of agricultural land capitalization. It is found that the logic of the capital itself, the profitability of the subject and the fragility of the ecological environment are the internal and external factors of the ecological risks of agricultural land. Thereupon authors put forward policy suggestions to prevent the ecological risks of agricultural land capitalization in terms of large-scale agricultural operations in diverse forms, the development of green agriculture, the protection of agricultural land quality and green finance, with a view to resolving the ecological risks of agricultural land capitalization and realizing the benign operation of agricultural land capitalization.

竹林鞭根系统研究综述

竹林鞭根系统是竹林生长发育的基础,在竹林生态系统能量流动和物质循环中扮演着重要角色。但目前对于竹林研究多集中于地上部分,地下鞭根系统对碳循环、生产力等的影响处于探索阶段,具体体现在研究局限于对鞭根系统生长和分布规律等基础的研究,而缺乏对相关机理及生态功能如碳汇方面的研究。此外,研究方法过于单一落后也是造成其难以深入的原因。基于此,本研究从竹林鞭根系统的结构特征、经营对鞭根系统结构的影响以及鞭根系统观测方法等方面论述国内外竹林鞭根系统研究现状,最后探讨分析竹林鞭根系统研究存在的问题。旨在为今后深入研究竹林鞭根系统的结构及其对竹林生态系统的作用提供参考。

毛竹林竹鞭生长特征和空间结构的探地雷达无损探测

【目的】发展毛竹林地下竹鞭空间结构的探地雷达无损探测方法,解决因毛竹竹鞭深入地下和观测不便而使空间结构及地下生物量无法准确预测的难题,为毛竹林地下竹鞭研究提供新思路。【方法】设置毛竹林样地并采用探地雷达进行探测,在雷达数据预处理后提取竹鞭信息,同时基于双曲线模型估计竹鞭直径,并利用直径(D)与长度(L)拟合竹鞭生物量,再用实测值进行模型检验,最后分析竹鞭的垂直与水平空间结构。【结果】探地雷达能有效探测毛竹林地下竹鞭的位置信息,双曲线模型对竹鞭直径和长度估计误差分别为-14.45%~20.66%和0.53%~8.51%,对空间位置3个方向(X,Y,Z)的估计误差分别为0.13%~6.65%、1.23%~6.55%和2.42%~7.41%;对于生物量,以DL为变量的多项式模型和以D2L为变量的指数模型拟合结果较好,确定系数R2为0.93~0.95,均方根误差RMSE为18.3~22.4 kg·hm^-2;从模型检验结果来看,以D2L为变量的指数和多项式模型模拟效果显著好于以D、D2和DL为变量的指数和多项式模型;以D2L为变量的指数模型是竹鞭生物量(BR)的最佳拟合模型,具体形式为BR=65.17e0.002D2L;对竹鞭空间结构分析表明,竹鞭主要垂直分布在0~40 cm土层,该土层竹鞭条数占竹鞭条数总量的91%,竹鞭鞭长和生物量分别占总量的95%和93%,且竹鞭直径在下层(>20 cm)土壤显著大于表层(0~20 cm)土壤;竹鞭在地下的走势较为曲折,空间分布相对均匀,同一竹鞭的直径差异不大,但不同竹鞭的直径差异显著(P<0.01),样地内单位面积竹鞭的长度和生物量分别为54080 m·hm^-2和1001.17 kg·hm^-2。【结论】利用探地雷达能成功探测地下竹鞭的位置信息,可得到竹鞭垂直和水平方向的空间结构,同时竹鞭直径模型与生物量模型的预测结果也较好,表明探地雷达技术可为研究毛竹林竹鞭结构及其动态与地上立竹的相互关系等提供技术支撑。

Measurement and Promotion Strategy of Poverty Alleviation Effect through Ecological Tourism in Huanggang City

Huangang City is rich in ecotourism resources,in which more than 80%of ecotourism resources concentrate in poor countryside.According to the statistics,there are 4 tourism counties,15 famous tourism villages and 115 rural tourist attractions.But economic development in ecotourism scenic spots of Huanggang City is relatively backward,and the development of ecological economy is imminent,especially ecological tourism.Based on research results on poverty alleviation effect through ecological tourism at home and abroad,Huanggang City is taken as research object,and two input indexes(per capita comprehensive tourism income and per capita tourist reception)and three output indexes(per capita GDP,per capita net income of farmers,and per capita disposable income of urban residents)are used to establish evaluation index system of poverty alleviation effect through ecological tourism.Based on DEA-BCC model,11 counties(cities and districts)in Huanggang City are taken as decision-making units,and empirical analysis on poverty alleviation effect through tourism is conducted from three aspects:comprehensive efficiency,technical efficiency and scale efficiency.

Estimation of rock Fe content based on hyperspectral indices

Information on the Fe content of bare rocks is needed for implementing geochemical processes and identifying mines.However,the influence of Fe content on the spectra of bare rocks has not been thoroughly analyzed in previous studies.The Saur Mountain region within the Hoboksar of the Russell Hill depression was selected as the study area.Specifically,we analyzed six hyperspectral indices related to rock Fe content based on laboratory measurements(Dataset I)and field measurements(Dataset II).In situ field measurements were acquired to verify the laboratory measurements.Fe content of the rock samples collected from different fresh and weathered rock surfaces were divided into six levels to reveal the spatial distributions of Fe content of these samples.In addition,we clearly displayed wavelengths with obvious characteristics by analyzing the spectra of these samples.The results of this work indicated that Fe content estimation models based on the fresh rock surface measurements in the laboratory can be applied to in situ field or satellite-based measurements of Fe content of the weathered rock surfaces.It is not the best way to use only the single wavelengths reflectance at all absorption wavelengths or the depth of these absorption features to estimate Fe content.Based on sample data analysis,the comparison with other indices revealed that the performance of the modified normalized difference index is the best indicator for estimating rock Fe content,with R2 values of 0.45 and 0.40 corresponding to datasets I and II,respectively.Hence,the modified normalized difference index(the wavelengths of 2220,2290,and 2370 nm)identified in this study could contribute considerably to improve the identification accuracy of rock Fe content in the bare rock areas.The method proposed in this study can obviously provide an efficient solution for large-scale rock Fe content measurements in the field.

Agricultural Ecological Capital: Factor Structure,Value Assessment and Accumulation Mechanism

As a kind of important new capital form,agricultural ecological capital plays a decisive role in guaranteeing healthy development of agricultural ecological economy. Therefore scientific understanding agricultural ecological capital is favorable for developing agricultural ecological economy,while clarifying factor structure,value assessment and accumulation mechanism of agricultural ecological capital is important content of understanding agricultural ecological capital. In this paper,factor structure of agricultural ecological capital is firstly elaborated,and it is thought that agricultural ecological capital is the unity of agricultural ecological environment,agricultural ecological resource and agricultural ecological system. Then agricultural ecological capital value is assessed according to use value method and non use value method,thereby realizing quantification of agricultural ecological capital. After agricultural ecological capital passes through value assessment,the value is more clear,which creates condition for agricultural ecological capital accumulation. Finally accumulation mechanism of agricultural ecological capital is analyzed. Accumulation channel of agricultural ecological capital is explored from natural and human factors,and it is found that agricultural ecological capital accumulates in the forms of agricultural ecological restoration and agricultural ecological compensation.

自然资源资本化价值诠释——基于自然资源经济学文献的思考

研究自然资源资本化,需要从价值形态上对自然资源有深入的认识。只有科学地认识自然资源资本化价值,才能把握其价值的完整性,准确地计量各类价值,促使自然资源从实物价值形态向货币价值形态转化,实现价值的最大化增值。基于此,文中通过对历年自然资源经济学文献的分析与总结,首先阐明了自然资源资本化的存在价值、劳动价值、稀缺价值与生态补偿价值;然后,依据修正后的李金昌模型,对自然资源资本化的各类价值进行了分类演化核算,得出了自然资源资本化价值核算的具体公式;最后,结合我国自然资源制度与实情,从产权界定、生态技术支撑、市场建设与政策支持四个维度提出了自然资源资本化价值实现的条件,期望从价值认识上转变资源开发模式,进而最终实现自然资源保值增值。

Evaluation of Agricultural Ecological Security in Hubei Province

With the promotion of agricultural ecological civilization construction in China, agricultural ecological security has received increasing attention. How to ensure agricultural ecological security has become a great concern for many scholars. As an important agricultural province in China, Hubei is of great significance to Chinese food security and agricultural sustainable development. This paper aims to establish an index system of agricultural ecological security and security classification of Hubei via Analytic Hierarchy Process and Pressure-State-Response methods. An evaluation of agricultural ecological security in Hubei, with a base of the national average value in 2015, reveals that the security degree has increased by 0.07566 from 0.90150 in 2005 to 0.97716 in 2015. Results show that agricultural ecological security in Hubei has improved but failed to reach the national average and there is still large space for improvement of the security level, considering a trend of deterioration in some indexes, such as per capita water resources, population density, per unit area pesticide load of farmland, forest coverage, grassland degradation rate and average annual precipitation. Influencing factors, especially population spatial distribution, misconduct in agricultural production, insufficient ability in agricultural natural disaster prevention, deficiency of agro-ecological technology of agricultural ecological security in Hubei are analyzed. For improvement of the degree of agricultural ecological security in Hubei, some countermeasures and suggestions are discussed.