Modeling fecundity in birds: Conceptual overview, current models, and considerations for future developments

Fecundity is fundamental to the fitness, population dynamics, conservation, and management of birds. For all the efforts made to measure fecundity or its surrogates over the past century of avian research, it is still mismeasured, misrepresented, and misunderstood. Fundamentally, these problems arise because of partial observability of underlying processes such as renesting, multiple brooding, and temporary emigration. Over the last several decades, various analytical approaches have been developed to estimate fecundity from incomplete and biased data. These, include scalar arithmetic formulae, partial differential equations, individual-based simulations, and Markov chain methodology. In this paper, we: (1) identify component processes of avian reproduction; (2) review existing methods for modeling fecundity; (3) place these diverse models under a common conceptual framework; (4) describe the parameterization, validation, and limitations of such models; and (5) point out future considerations and challenges in the application of fecundity models. We hope this synthesis of existing literature will help direct researchers toward the most appropriate methods to assess avian reproductive success for answering questions in evolutionary ecology, natural history, population dynamics, reproductive toxicology, and management.     

Application of Markov-chain model for vegetation restoration assessment at landslide areas caused by a catastrophic earthquake in Central Taiwan

The 921 earthquake caused a catastrophic disaster in Central Taiwan. Ten years have passed since the earthquake occurred. Vegetation succession is the basis for establishing a restoration reference which plays an important role in vegetation restoration at landslide sites. Generally, growth conditions for grass are easier and the growth rate is faster than that for trees. Therefore, grass can be considered a pioneer species or an important reference for the early vegetation succession stage. This is the reason why grass is required to be extracted from other land covers. Integrating remote sensing, geographic information system and image classification into vegetation succession models is very important. In this study, the Markov chain model was applied for vegetation restoration assessment and discussion. Chiufenershan and Ninety-nine peaks were selected as the study areas. Five SPOT satellite images are used for land cover mapping and vegetation restoration simulations. Four categories of land covers were extracted, including forest, grass, bare land and water, respectively. From the transitive probability matrix (derived from any two land covers), the results show that vegetation restoration at the Chiufenershan and Ninety-nine peaks landslide areas is ongoing, but that has been disturbed by natural disasters.     

我国北方城市暴雨灾害演化过程及风险分析

提出一种基于灾害演化网络的风险分析方法,针对城市暴雨灾害的演化过程进行了风险分析。利用复杂网络理论构建北方城市暴雨灾害演化网络模型,将危机事件分为三个等级,并探讨了事件级别和出入度的关系;分析城市暴雨灾害链演化特点和暴雨危机事件后果蔓延规律,得到关键危机事件和演化链。结果表明,交通堵塞是我国北方城市暴雨灾害系统中关键危机事件;暴雨灾害演化系统存在短链、长直链和循环链三种结构,其中循环链中的危机事件互为因果,可自行激化,是灾害演化网络控制的关键结构。     

渤海湾大型底栖动物群落优势种长期变化研究

以2008年4月,2009年5月、8月,2011年5月、9月以及2012年9月采集的大型底栖动物资料为基础,结合历史数据,描述渤海湾底栖动物群落优势种的变化规律,探讨变化原因.结果表明,近60年来,渤海湾底栖动物群落优势种多为营埋栖生活的小型双壳类和蟹类,而近几年则以小型双壳类为绝对优势种.其中,干扰耐受种凸壳肌蛤(Musculus senhousei)在渤海湾迅速增值并成为绝对优势种,影响了底栖动物群落结构的稳定性.胶州湾、莱州湾、辽东湾及渤海湾的主要优势种较为相似,变化规律皆为个体较大、生命周期较长的双壳类、虾蟹类逐步被个体更小、生命周期更短的干扰耐受种代替,说明4个海湾的底栖生态环境皆受到了一定程度的干扰.渤海湾优势种的变化可能与海湾本身的底质状况、人为干扰(如围海造陆工程的实施)、过量的陆源排污以及食物链的变化有关.     

Quantitative analysis of microbial biomass yield in aerobic bioreactor

We have studied the integrated model of reaction rate equations with thermal energy balance in aerobic bioreactor for food waste decomposition and showed that the integrated model has the capability both of monitoring microbial activity in real time and of analyzing biodegradation kinetics and thermal-hydrodynamic properties. On the other hand, concerning microbial metabolism, it was known that balancing catabolic reactions with anabolic reactions in terms of energy and electron flow provides stoichiometric metabolic reactions and enables the estimation of microbial biomass yield (stoichiometric reaction model). We have studied a method for estimating real-time microbial biomass yield in the bioreactor during food waste decomposition by combining the integrated model with the stoichiometric reaction model. As a result, it was found that the time course of microbial biomass yield in the bioreactor during decomposition can be evaluated using the operational data of the bioreactor (weight of input food waste and bed temperature) by the combined model. The combined model can be applied to manage a food waste decomposition not only for controlling system operation to keep microbial activity stable, but also for producing value-added products such as compost on optimum condition.     

广东省近18年粮食生产区域格局变化及成因分析

在分析建国以来广东省粮食生产历程及其阶段性特征的基础上，利用广东省1987～2004年分县统计数据，采用数理统计、区域差异定量分析与GIS空间分析等方法，研究了广东省近18年来粮食生产区域格局变化，并探讨了其影响因素，以期为进一步制定粮食宏观政策、保障广东省粮食安全提供参考依据。研究结果表明：1980年以来，广东省人均粮食占有量与全国人均粮食占有量之间的差距在逐渐增大；1987-2004年，广东省粮食生产中心逐渐北移；珠江三角洲粮食产量出现严重滑坡，粤东粤西地区处于低水平的相对稳定的粮食生产状态，而北部山区粮食产量经历了明显先升后降的过程，但在全省粮食生产的地位逐渐提升；珠江三角洲和粤东地区各县市区地域绝对差异和相对差异较大，18年间波动幅度也较大，而北部山区与粤西地区各县市区地域绝对差异和相对差异较小，变化幅度也较小；影响广东省粮食生产区域格局变化的主要因素包括工业化和城市化的迅速发展、种粮比较收益低下、粮食作物播种面积与产值构成的大幅下降以及经济体制的转型。     

Plenty of water,not enough strategy: How inadequate accessibility,poor governance and a volatile government can tip the balance against ensuring water security: The case of Nepal

Water security is arguably the single most important factor regarding the future sustainability of our planet. Without water we have no life, and with depleting freshwater resources conflict can easily ensue. The intersection between hydrology and politics requires a delicate balancing from decision-makers to ensure policy is well-informed and science is well communicated. In this paper, we discuss water issues currently faced by Nepal, a nation where freshwater resources are abundant yet political pressures are threatening future water security. We argue that despite adequate water supplies a nation may still experience severe water insecurity, particularly if effective governance and equitable access are not prioritised. We explore potential policy options necessary to achieve a holistic framework for water resources management, which we suggest, need to consider water resource reliability, accessibility and governance as fundamental pillars for ensuring water security.     

Effect of deep freezing of lakes on food supply in habitats of waterbirds

The phenomenon of bottom substrate exposure in deeply freezing lakes during the melting of ice in spring is described. It leads to the formation in the lake of a large temporary biotope—a combination of shoals and exposed portions of the silty bed—with a high trophic capacity for ducks, shorebirds, gulls, etc. The lake in such a state is a rich foraging area for nesting and migrating bird populations. This phenomenon, which is widespread in the Central Yakutian plain, is an ecological manifestation of cryoarid conditions developing in the plains due to extreme climate continentality.     

Reverse logistics in Malaysia: Investigating the effect of green product design and resource commitment

Reverse logistics and green product design are green supply chain management practices that are being implemented to demonstrate firm's commitment to environmental sustainability. The generation of waste from electrical and electronic equipments prompts the viability of product recovery to salvage invested material and energy. Selection of various reverse logistics product disposition options relies on products’ residual value and the accessibility of reusable content for re-entry in forward supply chain. This study explores the effect of green product design and resource commitment on reverse logistics product disposition by employing empirical analysis on 89 returned mail survey received from ISO14001 certified electrical and electronic manufacturing firms in Malaysia. The results indicated that design for disassembly is necessary to harvest valuable inventories from every product disposition options except of disposal whereas design for environment and commitment of resources have slight influence on repair and disposal activities. As the evidences show that green product design and reverse logistics product disposition are interrelated, firms ought to undertake environmentally proactive approaches to generate benefits from resources that are undeservingly discarded as landfill waste.