盐池县退耕还林生态效益评价

退耕还林工程是一项重要的生态环境工程措施,但到目前为止针对退耕还林工程的生态效益还没有统一规范的评价指标和方法。为此,以盐池县为例,建立了完善的适用于风沙区退耕还林工程效益评价的指标体系,对其生态效益进行评价。经分析,盐池县8年来取得的退耕还林生态效益达297 904.78万元,基本达到退耕还林工程的预期目标,其中:退耕还林保护水资源价值50 115.36万元,保护土地资源退化价值64 803.72万元,净化环境价值60 590.00万元,改善小气候价值31 942.05万元,保护农牧业价值17 472.84万元,保护生物多样性价值72 980.81万元。研究结果表明,实施退耕还林工程有效地改善了盐池县的生态环境,对风沙区后续退耕还林生态效益评价有一定的指导意义。     

吴旗县退耕还林生态效益价值评估

生态效益的评价和核算对评价林业生态工程的建设效果至关重要。综合运用专家咨询、理论分析法和频度分析3种方法。建立了吴旗县退耕还林生态效益评价指标体系，使用市场价值法、影子工程法、机会成本法和替代法等方法，对该县退耕还林6年来的生态效益进行了价值核算。结果表明：吴旗县退耕还林工程具有巨大的生态效益,核算后的总生态价值约为24．8亿元，其中拦蓄保护水资源价值为6．4亿元，保护土地资源退化价值为6亿元，净化空气价值为5．3亿元，改善小气候价值0．3亿元，保护农田价值为0．02亿元．增加生物多样性价值为6．7亿元。研究结果可为黄土区退耕还林工程建设效益评价提供参考。     

砒砂岩区沙棘人工林生态系统服务功能价值变化研究

依据《森林生态系统服务功能评估规范》构建评价指标体系,参照国内权威部门发布的价格参数,运用市场价值法、影子工程法、机会成本法等方法动态评价了我国砒砂岩区沙棘人工林生态系统服务功能价值.结果表明:保育土壤、涵养水源、积累营养物质、生物多样性保护和森林防护的总服务价值在2010年、2007年、2004年和2001年分别为52.83亿元、9.34亿元、3.59亿元、21.78亿元和24.78亿元,服务价值大小排序为:保育土壤＞森林防护＞生物多样性保护＞涵养水源＞积累营养物质;不同地区沙棘人工林生态系统服务功能价值排序为东胜市＞准格尔旗＞府谷县＞伊金霍洛旗＞达拉特旗＞杭锦旗;不同时间沙棘人工林单位面积生态服务功能价值排序为2010年＞2007年＞2004年＞2001年.研究结果可为砒砂岩区生态环境和经济建设可持续发展提供理论依据.     

甘肃祁连山森林生态系统服务功能及价值评估

 为引起各界对森林生态系统的重视,推进西北地区生态环境建设,采用影子工程法、市场价值法、替代花费法、机会成本法、收益资本化法等,对祁连山森林生态系统服务功能进行评估,得出祁连山每年森林生态系统服务功能总价值为2430亿元。其中涵养水源为930亿元,保育土壤为564亿元,固碳制氧为269139万元,净化空气为741亿元,保护生物多样性151亿元,森林景观与游憩价值168750万元。     

东平湖生态系统服务功能价值评估

运用生态系统学与生态经济学的方法对东平湖的主要生态系统服务功能价值进行了评估,得到东平湖生态系统服务功能价值总额为9.89亿元;其中调蓄洪水的价值为5.亿元,占总价值的5.89%;研究表明,东平湖生态系统服务功能主要表现在调蓄洪水、维持生物多样性等方面的价值.因此应发挥其主要服务功能,达到保护东平湖生态环境,保证湖区经济和生态环境的可持续发展.     

熵视角下延安市生态系统服务价值时空递变规律及其影响因子

退耕还林还草工程显著改变了延安市土地利用情况,进而改善了延安市的生态环境,评估这一过程的生态环境变化情况有利于后续生态保护与规划决策。基于1990—2020年土地利用、自然和社会统计数据,利用时间信息熵模型和地理探测器探究退耕还林还草工程实施前后延安市生态系统服务价值(ESV)时空递变规律及影响因子。结果表明:(1)1990—2020年延安市生态系统服务价值总体增加7.7亿元,增幅约32.42%。林地生态系统服务价值增加了11.25亿元,增幅为80.54%,是增长的主要贡献者,调节服务价值占比50%。(2)延安市生态系统服务价值整体呈现出"南高北低"的空间分布格局,有25.1%的区域ESV上升,分布在延安北部和中南部,6.4%的区域ESV降低,分布在各区县城郊地带。(3)归一化植被指数(NDVI)是ESV空间分异的主要影响因子,各因子间的交互作用共同影响了延安市的ESV空间分异。     

黄河中上游区土地使用结构与布局复合优化

黄河中上游地区生态环境脆弱,空间发展问题突出,探索该区域土地使用结构和布局优化配置是实现黄河流域生态保护和高质量发展的有效途径。该研究以黄河中上游地区为研究对象,基于该区域土地使用、社会经济等数据,运用多目标规划（multi-objective programming, MOP）和PLUS模型模拟了惯性发展、生态保护、经济优先和生态-经济均衡4种情景下研究区未来土地格局和变化趋势,并在平衡生态与经济的目标下提出最优土地使用结构和布局方案。结果表明：1）4种情景下,土地使用比例结构存在较大差异;2）均衡情景下的区域土地使用结构和空间布局方案为最优,其综合效益值最高且达到19481.01亿元,与生态保护情景相比其经济效益（12223.88亿元）增长了4.03%,与经济优先情景相比其生态价值（77257.12亿元）增长了2.32%;3）经济优先情景下综合效益值为20273.96亿元,是4种情景下最高的。研究可为黄河中上游区域未来土地使用规划编制和土地可持续利用规划提供依据。     

喀斯特石山区次生林恢复后生态服务价值评估——以广西壮族自治区马山县弄拉国家药物自然保护区为例

用生态经济学核算方法,定量评价了广西壮族自治区马山县弄拉次生林恢复后的生态服务价值。结果表明：恢复重建后的次生林具有极高的价值,1981～2006年弄拉次生林提供的服务价值累计超过8．82亿元人民币,其中直接利用价值为0．49亿元,占总价值的5．57％,间接使用价值为8．33亿元,占总价值的94．44％,间接使用价值远远大于直接使用价值。保护土壤价值、生物多样性的维持及科研文化价值分别为3．13亿元、1．74亿元及0．52亿元。弄拉次生林的恢复在防止水土流失、保护土壤肥力、维持或增加生物多样性和教育科研等方面具有极其重大的作用。     

吴起县土地利用变化及其生态服务价值研究

退耕还林工程实施以来,吴起县土地利用、生态环境都发生了明显的改善,生态服务价值也发生了较大的变化。运用Costanza提出的生态服务价值计算方法估算生态服务价值,结果表明:1990-2007年,土地利用结构不断优化,耕地、草地面积逐步减少,园地、林地面积逐步增加。1990年吴起县生态服务价值为16.41亿元,2001年为24.97亿元,2007年为28.19亿元。在生态服务功能价值构成中除了食物生产和废物处理功能外,其它生态服务功能都在增加。     

浅谈莱阳经济发展存在的问题及措施

近几年来，山东省莱阳市的经济得到了快速的发展。2007年，完成生产总值233亿元，比上年增长19．4％；实现地方财政收入67996万元，增长8．6％；规模以上工业销售收入532亿元、利税46亿元，分别增长25％和20％；实际利用外资1．57亿美元，出口创汇6亿美元，分别增长25．2％、19.5％。但是从横向、纵向比较来看，还是有差距的。特别是在地方财政收入方面来看，增长幅度太小，在烟台地区是低的。     

A proposed method to determine adequate amount of fertilizers to be applied to crops

To determine the adequate amounts of fertilizers to be applied to crops is one of the most important problems in the field of soil science.     

自动分析曲线线型并可绘图的计算机程序

本程序图文并茂,直观性强。而且,引入常数k的曲线模拟模型可提高精确度百倍以上,使其更适合理化特性或理论曲线的模拟分析。     

Adsorption of Orthophosphate to Humic-Fe-Complexes and to Amorphous Fe-Oxide

The adsorption of orthophosphate to humic surfaces was studied in a model experiment. The adsorption maximum of humic substances greatly increased with higher concentrations of organically complexed Fe (III), indicating that orthophosphate was bound to humic surfaces via metal bridges. The molar ratio P_adsorbed/Fe was nearly 1 for Fe freshly complexed to humic substances, whereas the ratio for amorphous Fe-oxide was a tenfold lower. An increase in pH from 5.2 to 6.2 lead to an increase of P-adsorption of about 30% in the case of humic-Fe-surfaces, which could be explained by an increased accessibility of adsorption sites at pH 6.2. The addition of a 0.01 M CaCl₂-matrix increased orthophosphate adsorption at pH 6.2 but not at pH 5.2. This could be explained by electrostatic interactions caused by the Ca⁺⁺ ion.     

土壤Se的分级与Se的植物有效性的关系

Nine soils with distinct properties and Se levels were selected to test a fractionation procedure of soil Se based on sequential extraction. Soil Se was fractionated into readily available Se (fraction Ⅰ, extracted by 0.5 M NaHCO₃), slowly available Se (fraction Ⅱ, extracted by 0.1 M NaOH-0.1 M Na₄P₂O₇), amorphous oxide-occluded Se (fraction Ⅲ, extracted by acid ammonium oxalate), free oxide-occluded Se (fraction Ⅵ, extracted by dithionite-citrate-bicarbonate buffer solution) and residual Se (fraction Ⅴ, determined by HNO₃-HClO₄ digestion of the final soil residue). The recovery of soil Se (the sum of all fractions over total soil Se determined independently) by this procedure was from 88.1% to 110.9%, mean 99.2%±6.4% for the test soils. The sum of fractions Ⅰ and Ⅱ, provided a good measure of available Se in soils and the percentage of fraction Ⅰ plus Ⅱ over the total soil Se, tentatively defined as Se availability index, could be used to indicate soil Se status and predict Se deficiency.     

引入分维理论评价土壤对优势流的敏感性

Food dye Brilliant Blue was introduced as the tracer in a dye-tracing experiment to obtain dye profile patterns of sandy loam soil,aeolian sandy soil,percolating paddy soil and permeable paddy soil.The dyed soil profiles were then photographed and the photos were scanned into a computer.Edited with certain software,only the dyed areas were left on the profile photos,which indicted the preferential flow paths for water and solute transport.Fractal dimensions of the dye patterns were calculated according to Arnold‘s function.Soil particle size distribution was analyzed by pipette method.The regression analysis showed that there was significant relationship between soil clay content and fractal dimension D of the dye pattern of soil profile.Based on the experiment results,the possibility of introducing fractal dimension to estimation of soil sensitivity to preferential flow is discussed.     

树盘覆草对果园生态环境的影响

苹果树盘覆草具有灭草、免耕、保墒、蓄水、增肥、防冻的作用，覆草改善了土壤水、肥、气、热状况，从而优化了土壤生态环境，促进土壤营养物质积累、分解、转化、更新，有利果树生长发育，从而显著提高果品的产量和质量。     

Chemical response of soil leachate to alternative approaches to experimental acidification

Abstract

One approach to evaluating computer models which predict terrestrial‐aquatic ecosystem response to acid deposition is the experimental acidification of soils with subsequent comparisons among predicted and measured soil solution response. Using a soil microcosm experimental approach, comparisions between simulated acid rain (i.e. dilute H₂SO₄), dry NH₄NO₃, and prilled reduced S were made for suitability for large‐scale field experiments. Soil microcosms consisting of reconstructed soil profiles received a background simulated throughfall dosing over the six month treatment period. Results indicated that simulated throughfall, applied at twice the ambient rate, acidified soil leachates approximately 0.5 pH units over the treatment period. Along with the decline in leachate pH was an apparent release of base cations as well as Fe and Al. Over the length of the treatment period, very little of the prilled S dissolved and the simulated acid rain treatment did not have significant effects on leachate chemistry.     

Using SAEM to estimate parameters of models of response to applied fertilizer

Many nonlinear functions have been used to predict crop yield response to applied fertilizer. Accurate estimates of the parameter values are required for the formulation of satisfactory fertilizer dose recommendations. In fertilizer trials, several yield measurements for different fertilizer doses are usually made at the same site and in the same year. Model errors are therefore unlikely to be independent for the same site-year. Nonlinear mixed effects models can be used for yield response data. We evaluated the performance of a recently proposed stochastic approximation of the EM algorithm (SAEM) for estimating the parameters of nonlinear mixed effects models. We used the SAEM method to estimate the parameters of four different nonlinear models, using a real dataset including 37 site-years of yield measurements. We then carried out simulations, to determine the bias and the root mean squared errors of the estimators. We compared the results obtained with SAEM with those obtained using a first-order conditional method. SAEM gave better results in most cases. The estimates produced by SAEM were less biased and less affected by initial values.     

A model to simulate response of plant stomata to environmental conditions

In order to simulate plant transpiration under different field climatic conditions we have developed and verified a semi-empirical model for predicting the stomatal response to solar global radiation, leaf temperature, vapour pressure difference between the leaf and ambient air, ambient air CO₂ concentration and soil water potential. The transpiration and the stomatal relative conductance of a Nicotania Tabaccum var “samsun” plant leaves were measured in a laboratory apparatus and compared to those predicted by the model: good agreement was obtained between them for the different investigated cases. The model was incorporated in a numerical greenhouse microclimate model and its effects on the canopy microclimate are discussed here.     

Stability of patulin to sulfur dioxide and to yeast fermentation.

The affinity of patulin for sulfur dioxide (SO2) is much less than was previously reported and is of little significance at the SO2 concentrations (below 200 ppm) used in the processing of apple juice and cider. However, at concentrations of 2000 ppm SO2 and 15 ppm patulin, combination was 90% complete in 2 days. Removal of SO2 liberated only part of the patulin, which suggests that 2 mechanisms are involved: one reversible (opening the hemiacetal ring) and one irreversible (SO2 addition at the double bond). Test with 2 yeasts used in English commercial cider making confirmed that patulin is effectively removed during yeast fermentation.