Constraints on foraging success due to resource ecology limit colony productivity in social insects

The benefit of group living is a fundamental question in social evolution. For sociality to evolve, each individual must gain in terms of some fitness component by living in larger groups. However, in social insects, a decrease in per capita success in brood production has been observed in larger groups. While it has been proposed that this decrease could be outweighed by an increase in the predictability of success, a functional basis to this hypothesis has so far never been demonstrated. In this paper, using foraging economics as a functional proxy to colony productivity, we construct a model to explore how number of foragers in the colony interacts with the ecology of resources to influence per capita foraging success and its predictability. The results of the model show that there is no increase in per capita foraging success in larger colonies under most circumstances, though there is an increase in its predictability. We then test the model with empirical data on the foraging behavior of the primitively eusocial wasp, Ropalidia marginata. The consistency between the data and the model suggests that foraging economics could provide a robust functional basis in explaining the relationship between colony size and productivity.     

Muhlbauer评分法在输油管道风险评价中的应用及分析

与其它运输方式相比,管道运输在正常运行情况下,其环境污染小。但是,产生事故后其环境风险大。本文利用Muhlbauer评分法对天津-北京航空煤油输送管道进行了风险评价,经过模拟计算后,定量分析了该输油管道的相对风险数,并提出了提高管道运行安全性的措施。评价结果表明:该管道的相对风险数为59,存在一定风险,但风险可接受。相对风险数中可变因素占66.5%,在不增加项目基建投资基础上,通过加强管理等措施,可提高可变因素的指数分值和相对风险数,使管道安全性能提高16.1%。     

土壤相对表观极性及其对有机污染物吸附的影响

以干土壤做气相色谱固定相,用测定气相色谱固定液相对极性的方法,测定了广州、四川云阳、太原、乌鲁木齐等地区的６种土壤相对表观极性（SRP）,及其基本性质。结果表明：ＳＲＰ（ｙ）与土壤有机质含量（x₁）、［O＋N］含量（x₂）呈正相关,与粘粒（＜0.01mm）含量（x₃）呈负相关,其关系式为y＝54.2705+17.7698x1+0.1834x₂-0.2014x₃,相关系数γ分别为0.9980、0.9463、-0.8792（n＝6,p<0.05）;随着SRP值的增加,萘和硝基苯的有机质吸附系数K_(om)下降。     

Sea level rise and eelgrass (Zostera marina) production: A spatially explicit relative elevation model for Padilla Bay, WA

The dynamics that govern the elevation of a coastal wetland relative to sea level are complex, involving non-linear feedbacks among opposing processes. Changes in the balance between these processes can result in significant alterations to vegetation communities that are adapted to a specific range of water levels. Given that current sedimentation rates in Padilla Bay, Washington are likely less than historical levels and that eustatic sea level rise is accelerating, the extensive Zostera marina (eelgrass) meadows in the bay may be at risk of eventual submergence. We developed a spatially explicit relative elevation model and used it to project changes in the productivity and distribution of eelgrass in Padilla Bay over the next century. The model is mechanistic and incorporates many of the processes and feedbacks that govern coastal wetland elevation change. Accretion estimates made using ²¹⁰Pb dating of sediment cores, sediment characteristics measured within cores, and eelgrass productivity and decomposition data were used to initialize and calibrate the model. Validation was performed using an elevation change rate measured with a network of surface elevation tables. Both the field data and model simulations revealed a net accretion deficit for the bay. Simulations using current rates of sea level rise indicated an overall expansion of eelgrass within Padilla Bay over the next century as it migrates from the center of the bay shoreward.     

Effects of soil nematodes communities on litter decomposition in urban forest of Dalian北大核心CSCD

In order to further expound the effect of soil nematodes on litter decomposition in urban forest, this study investigated the responses of soil nematodes communities to litter decomposition by litterbags technology at different mesh sizes in Dalian National Forest Park. Soil nematodes community composition, decomposition rate of litter and nutrient release were also analyzed. It found a total of 4 418 nematodes from 39 genera. Higher relative density of soil nematodes was found in the bags with 0.1 mm mesh size (1.55 individuals and 7.34 orders per g of dry litter) compared to the bags with 0.02 mm mesh size (0.21 individuals and 0.49 orders per g of dry litter). There were very few soil nematodes in the 0.02 mm litter bags. Thus we regarded that soil nematodes only affected the 0.1 mm litter bags. The mass loss rates as well as C and P release rates was higher in litter bags with 0.1 mm mesh size than in those with 0.02 mm mesh size, indicating a significant influence of soil nematodes on mass loss and nutrient release. The contribution of soil nematodes to the litter mass loss was about 24%. The effect of soil nematodes on the nutrient release rates differed among elements. The soil nematodes had a bigger influence on the release rate of N than that of other elements, whereas the influence on K release rate was the lowest. The results showed that soil nematodes communities has a significant effect on the litter decomposition and nutrient release of the forest litter in Dalian city, especially promoting the mass loss rates and N release rates.     

The role of local and landscape level measures of greenness in modelling boreal plant species richness

Measurements of primary productivity and its heterogeneity based on satellite images can provide useful estimates of species richness and distribution patterns. However, species richness at a given site may depend not only on local habitat quality and productivity but also on the characteristics of the surrounding landscape. In this study we investigated whether the predictions of species richness of plant families in northern boreal landscape in Finland can be improved by incorporating greenness information from the surrounding landscape, as derived from remotely sensed data (mean, maximum, standard deviation and range values of NDVI derived from Landsat ETM), into local greenness models. Using plant species richness data of 28 plant families from 440 grid cells of 25 ha in size, generalized additive models (GAMs) were fitted into three different sets of explanatory variables: (1) local greenness only, (2) landscape greenness only, and (3) combined local and landscape greenness. The derived richness–greenness relationships were mainly unimodal or positively increasing but varied between different plant families, and depended also on whether greenness was measured as mean or maximum greenness. Incorporation of landscape level greenness variables improved significantly both the explanatory power and cross-validation statistics of the models including only local greenness variables. Landscape greenness information derived from remote sensing data integrated with local information has thus the potentiality to improve predictive assessments of species richness over extensive and inaccessible areas, especially in high-latitude landscapes. Overall, the significant relationship between plants and surrounding landscape quality detected here suggests that landscape factors should be considered in preserving species richness of boreal environments, as well as in conservation planning for biodiversity in other environments.     

1978年长江中下游地区夏季大旱及其影响

本文利用相对距平和Z—指数为指标分析了1978年长江中下游地区的夏季大旱,并着重研究了干旱对该地区水资源和农业生产的影响。     

环境空气中VOC_S在线监测法与SUMMA罐采样气相色谱-质谱法比对研究

定性比较了环境空气VOCs在线监测法和SUMMA罐采样GC-MS法的基本原理、检测化合物种类和适用范围,并对标样实验、日均浓度、小时浓度从统计学角度进行了定量比对.研究表明,VOCs在线监测法监测结果与实验室方法有较好可比性,可用于相关领域VOCs的连续监控.     

Prioritizing ecological and human welfare risks from environmental stresses

The ecological systems of Earth are subjected to a wide array of environmental stresses resulting from human activities. The development of appropriate environmental protection and management policies and the appropriate allocation of resources across environmental stresses require a systematic evaluation of relative risks. The data and methodologies for comprehensive ecological risk assessment do not exist, yet we do have considerable understanding of econological stress-response relationships. A methodology is presented to utilize present knowledge for assignment of relative risks to ecological systems and human welfare from anthropogenic stresses. The resultant priorities, developed for the US Environmental Protection Agency's (EPA) relative risk reduction project, highlight global climate change, habitat alteration, stratospheric ozone depletion, and species depletion as the highest environmental risks, significantly diverging from the present emphasis by EPA and the public on toxic chemical issues. Enhanced attention to ecological issues by EPA and development of ecological risk assessment methodologies that value ecological and economic issues equitably are key recommendations.     

论建筑施工噪声管理中的执法对象

建筑施工噪声的执法对象是建设单位还是施工单位是长期未能统一的问题，分析两者在环境噪声污染防治中的责任与义务，阐述两者作为执法对象的利弊及法律依据，提出建设单位作为执法对象通过经济合同方式与施工单位进行环境责任与义务再分配的可行观战点，并建议对现行法律进行修改。