Socio-economic predictors of domestic wood use in an Atlantic forest area (north-east Brazil): a tool for directing conservation efforts

Given the excessive use pressure on forests, characterisation of the major users of forest resources can help guide conservation efforts. This study examines whether socio-economic variables explain domestic wood use in an area of Atlantic forest in the community of Três Ladeiras (Pernambuco, north-east Brazil). Socio-economic data were collected from 62 households, and geometric measurements of wood products in each household were taken to calculate the wood volume. An informant in each household indicated the average replacement time for each type of wood use. Data were analysed for static volume (wood volume found at the time of the visit) and dynamic volume (rate of wood consumption, calculated as the ratio between volume and replacement time). Multiple regression analyses were performed to determine the relationships between wood volume (static and dynamic) and the number of species used; independent variables including monthly family income, number of residents, average age of heads of the household, age of oldest household member, average residence time of heads of the household, average education level of heads of the household and education level of the most educated household member. Monthly income was inversely related to the static wood volume (adjusted R ² = 17.6%, p < 0.001), rate of wood consumption (adjusted R ² = 23.0%, p < 0.001) and number of species used (adjusted R ² = 22.3%, p < 0.001) and was the most important predictive variable for these three outcomes. Other factors such as average education level and average age of heads of the household were also explanatory variables of the total rate of wood consumption, as these two variables, together with monthly family income, explain 31.3% of the total dynamic volume. Given the high importance of income in our study, we suggest that future conservation strategies give special attention to the poorest members of the community.     

Effects of Harvest of Nontimber Forest Products and Ecological Differences between Sites on the Demography of African Mahogany

Abstract: The demographic impacts of harvesting nontimber forest products (NTFP) have been increasingly studied because of reports of potentially unsustainable harvest. Nevertheless, our understanding of how plant demographic response to harvest is altered by variation in ecological conditions, which is critical for developing realistic sustainable‐use plans, is limited. We built matrix population models to test whether and how variation in ecological conditions affects population responses to harvest. In particular, we examined the effect of bark and foliage harvest on the demography of populations of African mahogany (Khaya senegalensis) in two contrasting ecological regions of Benin, West Africa. K. senegalensis bark and foliage harvest significantly reduced its stochastic population growth rates, but ecological differences between regions had a greater effect on population growth rates than did harvest. The effect of harvest on population growth rates (Δλ) was slightly stronger in the moist than in the drier region. Life‐table response experiments revealed that the mechanism by which harvesting reduced λ differed between ecological regions. Lowered stasis (persistence) of larger life stages lead to a reduction in λ in the drier region, whereas lowered growth of all life stages lowered λ in moist region. Potential strategies to increase population growth rates should include decreasing the proportion of individuals harvested, promoting harvester‐owned plantations of African mahogany, and increasing survival and growth by promoting no‐fire zones in gallery forests. Our results show how population responses to harvest of NTFP may be altered by ecological differences across sites and emphasize the importance of monitoring populations over the climatic range in which they occur to develop more realistic recommendations for conservation.     

Examining Source-Receptor Relationships for Mercury in Scandinavia Modelled and Empirical Evidence

The atmosphere remains the major source of mercuryin Swedish ecosystems. Since the late eighties,atmospheric emissions of mercury have drasticallydecreased in Europe. Wet deposition of mercury hasdecreased over the last decade but still exhibitsa clear south-to-north gradient, greatlyinfluenced by source areas in northern and centralEurope. The decreases in emissions can beattributed to both direct measures to close knownpoint sources and a declining economy and energyconsumption in many East European countries.Further reductions of mercury emissions willrequire that other source categories such asindirect emissions from mercury-containingproducts and crematories are be considered.     

我国森林资源产品流动及其变化特征分析

论文运用物流分析的基本思想,基于我国森林资源产品产量、贸易量统计资料,采用统一单位“原木当量”(m₃),估算了1981～2000年森林资源采伐和产品加工环节的资源流量,进而分析我国森林资源产品流动的变化特征。结果表明,我国从“六五”(1981～1985年)到“九五”(1996～2000年)期间,消耗森林资源量分别为10230×104、11678×104、13444×104和16962×104m₃/a,呈加速增长趋势。其中,来自国外的资源流量占总流量的比重呈增加趋势,“六五”期间占19.1%,到“九五”期间上升为48.3%。流入资源以原木、木浆、纸及纸板、胶合板为主,它们主要来自北美、东亚、东南亚地区,有来源多地区化的变化趋向。森林资源在“六五”期间主要流向原木锯材类产品加工,随着产品流向结构的逐步改善,更多的资源流向人造板类产品的生产消费;纸类产品生产消费的资源流量增加迅速,但主要来自国外。     

基于耕地资源约束的中国大豆生产能力研究

论文首先在理论上系统分析了耕地资源约束与农产品生产能力之间的关系;以东北地区和黄淮海地区的大豆生产为重点,对主产区大豆生产的经济效益及影响大豆生产的资源、环境等其他问题进行了研究;并以县为基本单元,对中国大豆主产区未来大豆最大可能生产规模进行了预测;在分析大豆主产区大豆综合生产潜力基础上,研究提出了2020年之前中国大豆的最大可能生产能力在2800×10⁴～3400×10⁴t左右。但由于中国大豆生产和大豆加工存在严重的空间布局错位,应实施“南进北出”的大豆贸易战略;东北平原区的三江平原和松嫩平原是大豆增产潜力最大的地区,但该地区也是玉米主产区,扩大大豆种植面积必然带来玉米种植面积的下降,也将影响未来中国玉米的供求,所以,在耕地资源有限的情况下,应在“耕地资源-农产品”系统中研究耕地资源与农产品的综合平衡问题。     

电工电子产品燃烧产物的腐蚀损坏效应

电工电子产品陷入火灾后所产生的腐蚀性燃烧产物,可能会对电路和电工电子元器件的性能造成不同程度的损坏,使设备出现故障。测量和评估燃烧产物的腐蚀损坏效应对于保证与安全有关的电工电子设备正常运行是十分必要的。     

Comparison of in-house-developed ELISA with HPLC techniques for the analysis of atrazine residues

In-house developed ELISA was standardized to monitor atrazine residues in different environmental samples. The standard curve was linear, indicating an increase in log concentration with decrease in absorbance (%B/B₀ = 1.075–0.042 Log C; r = ?0.966). The middle of the test was at 75 ng/L and the lowest detection limit at 4 ng/L. ELISA significantly correlated with the high performance liquid chromatography (HPLC) (r = 0.990). Internal validation showed good accuracy and precision. Maximum atrazine residues were present in Jehlum River water/sediments and maize/sugarcane plant roots. Most of the food samples were found to be contaminated. ELISA required less clean-up steps than HPLC, but showed matrix effect in soil/colored extracts.     

Demographic Effects of Harvesting Epiphytic Bromeliads and an Alternative Approach to Collection

Abstract: Hundreds of epiphytic bromeliads species are harvested from the wild for trade and for cultural uses, but little is known about the effects of this harvest. We assessed the potential demographic effects of harvesting from the wild on 2 epiphytic bromeliads: Tillandsia macdougallii, an atmospheric bromeliad (adsorbs water and nutrients directly from the atmosphere), and T. violaceae, a tank bromeliad (accumulates water and organic material between its leaves). We also examined an alternative to harvesting bromeliads from trees—the collection of fallen bromeliads from the forest floor. We censused populations of T. macdougallii each year from 2005 to 2010 and of T. violaceae from 2005 to 2008, in Oaxaca, Mexico. We also measured monthly fall rates of bromeliads over 1 year and monitored the survival of fallen bromeliads on the forest floor. The tank bromeliad had significantly higher rates of survival, reproduction, and stochastic population growth rates (λ_s) than the atmospheric bromeliad, but λ_s for both species were <1, which suggests that the populations will decline even without harvest. Elasticity patterns differed between species, but in both, survival of large individuals had high elasticity values. No fallen bromeliads survived more than 1.5 years on the forest floor and the rate of bromeliad fall was comparable to current harvest rates. Low rates of population growth recorded for the species we studied and other epiphytic bromeliads and high elasticity values for the vital rates that were most affected by harvest suggest that commercial harvesting in the wild of these species is not sustainable. We propose the collection of fallen bromeliads as an ecologically and, potentially, economically viable alternative.     

Synergico: a method for systematic integration of energy efficiency into the design process of electr(on)ic equipment

This paper presents an overall design method to better consider the energy consumption of electrical and electronic equipment during the use phase. This aspect is often considered as the most important environmental aspect in active electrical and electronic equipment during its life cycle. The proposed method, called ‘Synergico’, characterises the product energy efficiency according to its modes, its functions and its sub-assemblies. It also articulates three tools: one assessment tool, one improvement tool and one environmental check tool. These tools are integrated along a typical product design process. The method therefore helps designing more energy-efficient products without compromising other performances such as ergonomics, functional performances, security, recyclability or costs. The three tools and the overall method are presented. A case study illustrates the way it works and is discussed.     

A Systematic Procedure for Modeling Usability Based on Product Design Variables: A Case Study in Audiovisual Consumer Electronic Products

A systematic modeling approach to describing, prescribing, and predicting usability of a product has been presented. Given the evaluation results of the usability dimension (UD) and the measurement of the product’s design variables, referred to as the human interface elements (HIEs), the approach enables one to systematically assess the relationship between the UD and HIEs. The assessed relationship is called a usability model. Once built, such a usability model can relate, in a quantitative manner, the HIEs directly to the UDs, and thus can serve as an effective aid to designers by evaluating and predicting the usability of an existing or hypothetical product. A usability model for elegance of audiovisual consumer electronic products has been demonstrated.