省域尺度下不同时序景观指数集与粒度效应分析

[目的]景观格局变化是景观生态学中的热点问题。研究省域尺度下不同时序景观指数的粒度效应、选取计算景观指数所需的适宜粒度范围并筛选出代表性景观指数集对分析景观格局变化具有重要意义。[方法]以安徽省土地覆被为研究对象,以2000年、2005年、2010年的Landsat TM遥感影像为主要数据源,采用土地利用转移矩阵对安徽省土地覆被的转移数量与方向进行研究;通过设置不同的栅格大小研究景观指数的粒度效应并选取合适的粒度范围;基于相关性分析、因子分析与敏感性分析,筛选出代表性景观指数集。[结果](1) 2000—2010年安徽省的土地覆被始终以耕地为主,其次是林地与人工表面;人工表面的增加是建立在耕地面积减少基础之上的,在10年间共有超过3 200km2的耕地转化为人工表面;(2)景观指数存在粒度效应,粒度变化会对景观指数的计算结果产生影响;省域尺度下计算景观指数所需的合适粒度范围为100～125m;(3)研究安徽省景观格局变化的代表性景观指数有4个,分别为最大斑块指数、景观形状指数、平均斑块面积、香农多样性指数。[结论]计算安徽省景观指数的适宜粒度范围为100～125m,安徽省的代表性景观指数集为最大斑块指数、景观形状指数、平均斑块面积、香农多样性指数,为进一步研究景观格局变化及驱动机制提供了依据。     

某微型车前纵梁与前轮罩连接结构改进

整车可靠性路试和小批量造车是检验车身设计是否成功的重要手段。文章针对某微型车前轮罩总成的结构件在整车耐久性路试(路试里程为39 000 km)中的开裂问题、生产车间关于此部分零件的造车问题反馈以及冲压工艺问题进行分析,并成功地解决和优化。     

略论农业科技期刊封面设计的地域文化性

地域文化是期刊美术工作者可以深度挖掘的艺术宝藏。文章以《农村新技术》杂志为例,分析了期刊美术设计引入地域文化的重要性,并从突出地方特色、抓典型、求真实等方面作了较全面的论述,说明引入地域文化资源和自然资源对构筑农业科技期刊特色品牌、扩大期刊的知名度和传播力、提升中华文化的世界影响力之意义重大。     

城市LUCC时空格局对地表温度的影响效应研究 ——以广西柳州市为例

研究目的:定量分析中国西南典型重工业城市——柳州市的土地利用、地表温度时空演化特征以及不同土地利用类型对地表温度的联合影响效应。研究方法:利用1991年Landsat 5的TM影像和2013年Landsat 8的OLI/TIRS影像数据,通过遥感技术反演提取研究区归一化植被指数(NDVI)、归一化差异建筑指数(NDBI)、改进的归一化差异水体指数(MNDWI)以及地表温度(LST)等遥感参数,基于遥感指数叠加分类法获取城市土地利用/覆盖(LUCC)信息。研究结果:(1)柳州市22年间LUCC变化剧烈,受人为因素影响强烈的地物类型为建筑用地、耕地和裸地。其中,建筑用地变化幅度最大,面积增加了126.71%,新增建筑用地主要源于城市中原有的耕地类型。(2)两期地表温度数据均显示,城市建筑用地的地表温度最高,水体的地表温度最低,建筑用地升温效果显著,是造成城市热岛效应的主要原因之一。(3)影响因子相关性与多元回归分析揭示,城市中各地物类型面积比与地表温度均具有一定的相关性,但差异性较大。其中,建筑用地、裸地与地表温度呈正相关,林地、水体与地表温度呈负相关。研究结论:城市各种LUCC类型的地表温度差异较大,水体和林地在缓解城市热岛效应方面作用十分显著,两者比较,水体的降温效果要优于林地。     

Applying search theory to determine the feasibility of eradicating an invasive population in natural environments

The detectability of invasive organisms influences the feasibility of eradicating an infestation. Search theory offers a framework for defining and measuring detectability, taking account of searcher ability, biological factors and the search environment. In this paper, search theory concepts are incorporated into a population model, and the costs of search and control are calculated as functions of the amount of search effort (the decision variable). Simulations are performed on a set of weed scenarios in a natural environment, involving different combinations of plant longevity, seed longevity and plant fecundity. Results provide preliminary estimates of the cost and duration of eradication programs to assist in prioritising weeds for control. The analysis shows that the success of an eradication program depends critically on the detectability of the target plant, the effectiveness of the control method, the labour requirements for search and control, and the germination rate of the plant.     

基于中分辨率遥感图像的土地利用与覆被分类系统构建

研究目的:研制基于遥感的土地利用与覆被分类系统,为国家土地利用与覆被基础数据库建设和宏观土地资源遥感动态监测提供分类依据。研究方法:文献资料法、比较分析法和计算机试验法。研究结果:根据中分辨率卫星传感器的波谱响应特征和土地利用与覆被遥感信息获取技术,提出基于中分辨率遥感图像的土地利用与覆被分类系统,并给出各个类别在遥感图像上的解译标志。研究结论:该系统基本可以满足在国家尺度上的遥感分类应用要求。     

Rural-urban gradient analysis of ecosystem services supply and demand dynamics

Urban regions are important places of ecosystem service demands and, at the same time, are the primary source of global environmental impacts. Although there is broad agreement on the importance of incorporating the concept of ecosystem services into policy strategies and decision-making, the lack of a standardized approach to quantifying ecosystem services at the landscape scale has hindered progress in this direction. Moreover, tradeoffs between ecosystem services and the supply/demand ratio of ecosystem services in urban landscapes have rarely been investigated. In our paper, we present a method to quantify and map the supply and demand of three essential provisioning services - energy, food, and water - along the rural-urban gradient of the eastern German region Leipzig-Halle. This urban region has experienced significant socio-economic dynamics and land use changes since the German reunification in 1990. The results show that both the demand and the supply of ecosystem services changed considerably during the time span under consideration (1990-2007). We identified an increasing supply/demand ratio of food and water but a decreasing supply/demand ratio of energy. In addition, the pattern of ecosystem demands shows a levelling of rural-urban gradients, reflecting profound modifications of traditional rural-urban relationships. The changes of ecosystem service supply gradients are determined more by land use intensity, such as the intensification of agricultural production, than by land cover changes such as urban sprawl. The comparison of supply/demand ratios and rural-urban patterns of ecosystem services can help decision-makers in landscape management in striving for a sustainable balance between resource supply and demand.     

The institutional drivers of sustainable landscapes: a case study of the ‘Mayan Zone’ in Quintana Roo, Mexico

Research on the dynamics of tropical forest land use and cover change (LUCC) has focused on the three scenarios: (1) deforestation/degradation; (2) settled, degraded areas in recovery, and (3) sparsely settled, expansive, intact forest. Through examination of a central Quintana Roo, Mexico case study we propose a fourth scenario of a ‘sustainable landscape’: an inhabited, productively used, forested landscape that nonetheless shows little change or net gains in forest cover over the last 25 years. We use Landsat images to demonstrate a low incidence of net deforestation, 0.01% for the 1984–2000 period, the lowest recorded deforestation rate for southeastern Mexico. Institutional innovations such as an agrarian reform process that established large common property forests for non-timber forest product extraction, and later innovations such as sustainable forest management institutions have driven the outcome of low net deforestation, added to multiple organizational processes that promote sustainable land use.     

Mapping mountain diversity: Ethnic minorities and land use land cover change in Vietnam's borderlands

In the complex agro-ecological conditions of Vietnam's northern borderlands, attempts by ethnic minority farmers to create sustainable livelihoods, along with the impacts of state development policies, have direct consequences for land use and land cover (LULC) change. In this paper we analyse the degree to which LULC has changed and diversified from 1999 to 2009 in Lào Cai Province and the underlying relationships with ethnic minority livelihood diversification strategies. We examine the correlation between LULC diversity and various socioeconomic and biophysical proxies using a spatial autoregressive model. Our findings indicate two major changes in LULC: an increase in closed canopy forest and substantial urban growth. LULC diversity increased between 1999 and 2009, suggesting a transition between land uses and/or a diversification of livelihood strategies. Socioeconomic proxies are significant predictors of LULC diversity in both years, while biophysical proxies are only effective predictors in 2009. In-depth interviews regarding state-led policies and ethnic minority livelihoods reveal some of the underlying mechanisms of such LULC transitions and associations.     

How to overcome the implementation gap in ecosystem services? A user-friendly and inclusive tool for improved urban management

One of the main issues with the concept of ecosystem services is its absence on the ground in concrete operational decision-making contexts; that is, an implementation gap. In this study, we investigated if this gap could be overcome through the use of open-source data and free tools, and the adoption of a short-term participatory process. We tested these methods in the context of a project in the urban metropolitan area of Bordeaux (Communauté urbaine de Bordeaux: CUB) in France. The ecosystem services were defined using a participatory approach involving local stakeholders, and then selected scenarios were simulated to test the impact of various development or conservation plans. The study addressed three main questions: (1) Is it possible to adopt a simple methodological approach that overcomes the implementation gap through the development of a user-friendly and inclusive method? (2) What is the added value of a participatory approach? (3) With regards to four scenarios in this territory, what are the ES trends in the selected biophysical and monetary indicators, and will knowledge of these trends help planners to shape a sustainable trajectory for the territory?