模拟退火法优化约束条件下造林规划设计的研究

模拟退火法是一种新的优化算法 ,文中首次提出用该法确定在资金、计划、苗木品种和数量等约束条件下小班造林规划设计最优方案 ,并阐述其数学模型和具体方法。笔者用97个造林小班资料 ,应用模拟退火法对在约束条件下的小班造林规划设计进行了方案优化 ,结果表明该法优化约束条件下造林规划设计效果很理想。     

阜新市煤矸石山的综合治理

分析了煤矸石山对空气、水、土壤等环境的影响。针对阜新矿区煤矸石山的现状，介绍了煤矸石山自燃治理、煤矸石综合利用途径和煤矸石山造林绿化的有效方法，提出了对阜新市煤矸石山综合治理工作的几点建议。     

三峡库区移民城市绿化问题的初步探讨——以万县市为例

库区移民城市绿化一定程度上对三峡工程有重要影响。应根据生态效益原则、经济效益原则、净化环境原则、城市美化原则和地理气候原则，对街道绿化、工业区绿化和生活、文化、娱乐场所绿化进行不同树种的选样与配置，使库区移民城市的绿化为三峡库区的持续发展发挥积极的作用。     

城乡绿化工程中的生物多样性探讨

在城乡绿化工程中不注意生物多样性,会造成生长不良,绿化成本高,不能很好发挥生态功能等问题。应采用生态绿化方法-选择适应地域特点的多种绿化模式,上百种本乡的品质优良、具有生长优势的乔灌木、花、草品种进行绿化。     

Carbon Offset Potentials of Four Alternative Forest Management Strategies in Canada: A Simulation Study

Using an Integrated TerrestrialEcosystem C-budget model (InTEC), we simulated thecarbon (C) offset potentials of four alternativeforest management strategies in Canada: afforestation,reforestation, nitrogen (N) fertilization, andsubstitution of fossil fuel with wood, under differentclimatic and disturbance scenarios. C offset potentialis defined as additional C uptake by forest ecosystemsor reduced fossil C emissions when a strategy isimplemented to the theoretical maximum possibleextent. The simulations provided the followingestimated gains from management: (1) Afforesting allthe estimated 7.2 Mha of marginal agricultural landand urban areas in 1999 would create an average Coffset potential of 8 Tg C y^-1 during 1999–2100,at a cost of 3.4 Tg fossil C emission in 1999. (2)Prompt reforestation of all forest lands disturbed inthe previous year during 1999–2100 would produce anaverage C offset potential of 57 Tg C y^-1 forthis period, at a cost of 1.33 Tg C y^-1. (3)Application of N fertilization (at the low rate of 5kg N ha^-1 y^-1) to the 125 Mha ofsemi-mature forest during 1999–2100 would create anaverage C offset of 58 Tg C y^-1 for this period,at a cost of 0.24 Tg C y^-1. (4) Increasingforest harvesting by 20% above current average ratesduring 1999–2100, and using the extra wood products tosubstitute for fossil energy would reduce averageemissions by 11 Tg C y^-1, at a cost of 0.54 TgC y^-1. If implemented to the maximum extent, thecombined C offset potential of all four strategieswould be 2–7 times the GHG emission reductionsprojected for the National Action Plan for ClimateChange (NAPCC) initiatives during 2000–2020, and anorder of magnitude larger than the projected increasein C uptake by Canada's agricultural soils due toimproved agricultural practices during 2000–2010.     

黄土高原土壤水资源与植树造林

论文在对黄土高原土壤水分资源的赋存条件和土壤水分循环与平衡分析基础上，讨论了人工林系统的土壤水文效应、土壤干燥化──土壤干层的形成与植树造林问题。     

上海城市街道峡谷道路绿化模式研究

街道峡谷在上海城市中普遍存在,街道峡谷中污染气体的扩散受到屋顶风向、风速、高宽比、峡谷两侧建筑物的对称性、高度分布和街区形状等因素的影响。文章对适合于不同街道峡谷形式的、较为典型的道路绿化模式进行了研究。结果表明,上海城市街道峡谷中的道路绿化模式可归纳为:梯级递进式、斑块复合式、疏朗开敞式、模纹花镜式和独立行道树式5种。当街道峡谷与主导风垂直:(1)街道峡谷的W/H>5且为平行型峡谷时,绿化模式应采用梯级递进式或疏朗开敞式;(2)街道峡谷的W/H为0.6～5且为平行型峡谷时,绿化模式在迎风侧采用流朗开敞式、背风侧采用模纹花镜式,或者两侧都采用模纹花镜式;(3)街道峡谷的W/H<0.6且为平行型峡谷时,绿化模式应采用模纹花镜式或独立行道树式;(4)街道峡谷的W/H<0.6且为递升型峡谷时,绿化模式在迎风侧采用斑块复合式或模纹花镜式,背风侧采用模纹花镜式或独立行道树式;(5)街道峡谷的W/H<0.6且为递降型峡谷时,绿化模式可采用模纹花镜式或独立行道树式;当街道峡谷与主风向平行:宽、高比大的街道绿化模式应采用梯级递进式或斑块复合式,当街道峡谷的高度是宽度的倍数时,道路绿化宜采用疏朗开敞式或独立行道树式。     

Afforestation for reduction of NOX concentration in Lanzhou China

Lanzhou is one of the major industrial cities in northwest China, the capital of Gansu Province, and located at a northwest-to-southeast oriented valley basin with elevation about 1500–1600-m. Due to topographic and meteorological characteristics, Lanzhou is one of the most polluted cities in China. Meteorological conditions (low winds, stable stratification especially inversion), pollutant sources and sinks affect the air quality. Lanzhou government carried out afforestation and pollutant-source reduction (closing several heavy industrial factories) to improve the air quality for the past two decades. In this study, effect of afforestation on reducing the NO_X concentration is investigated numerically using RAMS-HYPACT model.     

长江上游生态建设工程与植被覆盖时空变化的响应特征研究

"退耕还林"、"天然林保护"等重大生态建设工程在长江上游实施已有十余年,剖析重大生态建设工程实施以来长江上游植被覆盖时空变化特征与生态建设投入间的响应关系,对区内未来生态建设的布局具有重要指导意义。以年际时间序列的SPOT-VEGETATION NDVI遥感数据为基础,利用遥感及地理信息系统技术,趋势拟合等方法,研究长江上游地区2002年至2013年植被覆盖时空动态变化特征。并以县级行政区为单元,分析长江上游植被覆盖时空变化与生态建设工程投入的响应关系。结果表明:研究区内植被指数NDVI(Normalized Difference Vegetation Index)整体呈现缓慢增加趋势,年均增长率为1.06%,主要体现为中等植被覆盖向高植被覆盖转化;植被覆盖增加区域远远大于植被覆盖减少区域,其中增加的区域占整个长江上游流域的86.02%,主要分布于秦巴山地以北、云贵高原以及横断山区中小起伏的山地;植被覆盖减少区域占6.09%,主要分布于汶川地震灾区以及成都,重庆、昆明等大型城市群及其周边。其次,近10 a生态建设重大工程投资对长江上游植被覆盖增长起促进作用,在研究区内有261个县级行政区具有较好的造林效率,达县级行政区总数的90%,集中分布于云贵、川陕交界处及西部高山、高原区。     

Modeling the Potential of the Northern China Forest Shelterbelt in Improving Hydroclimate Conditions1

Abstract: The forest shelterbelt (afforestation) project in northern China is the most significant ecosystem project initiated in China during the past three decades. It aims to improve and conserve the ecological environment in the project areas. The tree belt stands along the southern edge of the sandy lands, nearly paralleling to the Great Wall. This study used a regional climate model to simulate the potential of improving regional hydroclimate conditions resulting from the afforestation project. Two simulations with preafforestation and postafforestation land cover were performed over East Asia from January 1987 to February 1988. The model resolution is 60 km. The differences between the two simulations suggest that the northern China forest shelterbelt project is likely to improve overall hydroclimate conditions by increasing precipitation, relative humidity, and soil moisture, and by reducing prevailing winds and air temperature. The effects are more significant in spring and summer than fall and winter. Changes in many hydrologic properties (e.g., evapotranspiration, soil moisture, and water yield), however, differ between the dry Northeast China and the moist Northeast China. The hydroclimate effects are also found in the surrounding areas, featured by noticeably moister conditions in the area south of the afforestation project. The results imply that the shelterbelt project would reduce water yield in afforested Northwest and North China during spring, but increase water yield in the afforested Northeast China as well as in the southern surrounding area, offset some greenhouse effects, and reduce the severity of dust storms. Possible improvements of this study by using actual afforestation data, modeling with higher resolution, longer integration and more detailed processes, and analyzing the physical mechanisms are discussed.