The Waste Input-Output Approach to Materials Flow Analysis

Abstract: A general analytical model of materials flow analysis (MFA) incorporating physical waste input-output is proposed that is fully consistent with the mass balance principle. Exploiting the triangular nature of the matrix of input coefficients, which is obtained by rearranging the ordering of sectors according to degrees of fabrication, the material composition matrix is derived, which gives the material composition of products. A formal mathematical definition of materials (or the objects, the flow of which is to be accounted for by MFA) is also introduced, which excludes the occurrence of double accounting in economy-wide MFAs involving diverse inputs. By using the model, monetary input-output (IO) tables can easily be converted into a physical material flow account (or physical input-output tables [PIOT]) of an arbitrary number of materials, and the material composition of a product can be decomposed into its input origin. The first point represents substantial saving in the otherwise prohibitive cost that is associated with independent compilation of PIOT. The proposed methodology is applied to Japanese IO data for the flow of 11 base metals and their scrap (available as e-supplement on the JIE Web site).     

Interclonal variation in diel horizontal migration behaviour of the water flea <Emphasis Type="Italic">Daphnia magna</Emphasis>—searching for a signature of adaptive evolution

In shallow temperate lakes, zooplankton populations may exhibit diel horizontal migration (DHM) and move towards macrophytes during the day to avoid fish. Using a natural Daphnia magna population, we undertook an experimental investigation aimed to describe the genetic variation for DHM and to study whether an adaptive micro-evolutionary response occurred to changes in macrophyte coverage and fish predation pressure through time. Twenty-seven D. magna clones were hatched from ephippia in the sediment of shallow Lake Ring, Denmark. This lake was eutrophied during the 20th century and was subject to restoration measures in the 1970s. The DHM behaviour of the clones was observed both in the presence and absence of fish kairomone. Significant interclonal variation in DHM behaviour occurred in both treatments. To study the micro-evolutionary response of the Lake Ring D. magna population, two approaches were used. First, we compared the DHM behaviour of clones derived from ephippia collected at different depths. A comparison was conducted between clones resurrected from the period of eutrophication (1960–1980) and from the period of recovery (1986–2000). A significant treatment (presence and absence of fish kairomone) × period interaction effect was identified, suggesting a significant micro-evolutionary response for DHM behaviour. The D. magna clones exhibited a significantly stronger horizontal migration response during the period of eutrophication than in the recovery phase. Second, clonal means, representing the influence of the genotype on the trait, were correlated with environmental conditions (macrophyte cover, fish predation pressure and Secchi depth). The results of this analysis also suggest that a micro-evolutionary response by Daphnia has occurred in reaction to changes in fish predation pressure. In periods with high fish predation pressure, Daphnia migrated more strongly towards the plants. Guest editor: Piet Spaak Cladocera: Proceedings of the 7th International Symposium on Cladocera     

Comparison of methods for total community DNA extraction and purification from compost

The differences on DNA yield and purity of three different DNA extraction protocols were compared with regard to the use for PCR and other molecular analyses. Total DNA was extracted from compost by the three protocols, and then was purified by spin-bind cartridges after being precipitated by PEG8000. The detection performed on a nucleic acid and protein analyzer showed that all three methods produced high DNA yields. The agarose gel electrophoresis showed that the fragments of crude and purified DNA had a length of about 23 kb. A eubacterial 16S rRNA gene-targeted primer pair was used for PCR amplification, and full length 16S rDNAs were amplified from all the purified DNA samples. After being digested by restriction endonucleases, the restriction map of amplified rDNA showed identical genetic diversity. The products of PCR using primer pair GC341F and 907R were also used for denaturing gradient gel electrophoresis analysis. The results indicated that high-quality DNA was extracted from compost by the three protocols, and each of the protocols is adapted to extract microbial genome DNA from compost expediently and cheaply.     

Photosynthetic acclimation of the liana Stigmaphyllon lindenianum to light changes in a tropical dry forest canopy

Tropical plant canopies show abrupt changes in light conditions across small differences in spatial and temporal scales. Given the canopy light heterogeneity, plants in this stratum should express a high degree of plasticity, both in space (allocation to plant modules as a function of opportunity for resource access) and time (photosynthetic adjustment to temporal changes in the local environment). Using a construction crane for canopy access, we studied light acclimation of the liana Stigmaphyllon lindenianum to sun and shade environments in a tropical dry forest in Panama during the wet season. Measured branches were randomly distributed in one of four light sequences: high- to low-light branches started the experiment under sun and were transferred to shade during the second part of the experiment; low- to high-light branches (LH) were exposed to the opposite sequence of light treatments; and high-light and low-light controls , which were exposed only to sun and shade environments, respectively, throughout the experiment. Shade branches were set inside enclosures wrapped in 63% greenhouse shade cloth. After 2 months, we transferred experimental branches to opposite light conditions by relocating the enclosures. Leaf mortality was considerably higher under shade, both before and after the transfer. LH branches reversed the pattern of mortality by increasing new leaf production after the transfer. Rates of photosynthesis at light saturation, light compensation points, and dark respiration rates of transferred branches matched those of controls for the new light treatment, indicating rapid photochemical acclimation. The post-expansion acclimation of sun and shade foliage occurred with little modification of leaf structure. High photosynthetic plasticity was reflected in an almost immediate ability to respond to significant changes in light. This response did not depend on the initial light environment, but was determined by exposure to new light conditions. Stigmaphyllon responded rapidly to light changes through the functional adjustment of already expanded foliage and an increase in leaf production in places with high opportunity for carbon gain. Received: 24 April 1998 / Accepted: 11 May 1999     

Species co‐occurrence patterns and dietary resource competition in primates

Diamond (Assembly of species communities. In: Cody ML, Diamond JM, editors. Ecology and evolution of communities. Cambridge: Belknap. p 342–444 ( 1975 )) argued that interspecific competition between species occupying similar niches results in a nonrandom pattern of species distributions. In particular, some species pairs may never be found in the same community due to competitive exclusion. Rigorous analytical methods have been developed to investigate the possible role that interspecific competition has on the evolution of communities. Many studies that have implemented these methods have shown support for Diamond's assembly rules, yet there are numerous exceptions. We build on this previous research by examining the co‐occurrence patterns of primate species in 109 communities from across the world. We used EcoSim to calculate a checkerboard (C) score for each region. The C score provides a measure of the proportion of species pairs that do not co‐occur in a set of communities. High C scores indicate that species are nonrandomly distributed throughout a region, and interspecific competition may be driving patterns of competitive exclusion. We conducted two sets of analyses. One included all primate species per region, and the second analysis assigned each species to one of four dietary guilds: frugivores, folivores, insectivores, and frugivore‐insectivores. Using all species per region, we found significantly high C scores in 9 of 10 regions examined. For frugivores, we found significantly high‐C scores in more than 50% of regions. In contrast, only 23% of regions exhibited significantly high‐C scores for folivores. Our results suggest that communities are nonrandomly structured and may be the result of greater levels of interspecific competition between frugivores compared to folivores. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.     

Bacterial diversity in the bulk soil and rhizosphere fractions of Lolium perenne and Trifolium repens as revealed by PCR restriction analysis of 16S rDNA

The rhizosphere of Trifolium repens and Lolium perenne was divided into three fractions: the bulk soil, the soil adhering to the roots and the washed roots (rhizoplane and endorhizosphere). After isolation and purification of DNA from these fractions, 16S rDNA was amplified by PCR and cloned to obtain a collection of 16S rRNA genes representative of the bacterial communities of these three fractions. The genes were then characterized by PCR restriction analysis. Each different profile was used to define an operational taxonomic unit (OTU). The numbers of OTUs and the numbers of clones among these OTUs allowed to calculate a diversity index. The number of OTUs decreased as root proximity increased and a few OTUs became dominant, resulting in a lower diversity index. In the root fraction of T. repens, the restriction profile of the dominant OTU matched the theoretical profile of the 16S rRNA gene of Rhizobium leguminosarum. This study showed that plant roots create a selective environment for microbial populations.     

山地麻蜥越冬及其耐饥力的观察

据调查,徐州山地麻蜥的入蛰时间为１２月中旬;出蛰时间为翌年２月中旬,冬眠期为２个月左右。生活在丘陵山地的山地麻蜥是穴居在大石块下松土中过冬的。冬眠期的活动与温度高底有一定的关系。冬眠期山地麻蜥有较强的耐饥能力。     

Zonation pattern of an isolated mangrove community at Playa Medina,Venezuela

This study focuses on a mangrove system which is completely isolated from the sea, lacking any connecting tidal channels or creeks and far enough from the coastline to prevent tidal flushing. The reason why it has become isolated remains unclear. But it is obvious that this situation may have introduced important changes in soil salinity and hydrological patterns, which might be reflected in the present composition and zonation patterns of the mangrove community. Main findings of this study suggest that: (1) Plant species distribution is affected mainly by water logging and mineral content of soils. (2) Ground water is the only permanent supply of water and salts to the isolated mangrove. (3) Soils are subjected to different degrees of leaching of salts. (4) The K: Na ratios support that mangrove community is not subjected to salinity stress. (5) Continuous leaching of salts favor the advance of terrestrial non-halophytes plants.     

山东省不同植被区内野生植物根围AM菌的生态分布

ＡＭ菌是土壤习居菌 ,生态适应性强 ,可发生在各种生态环境。寄主范围也十分广泛 ,除少量植物如莎草科、苋科、灯心草科、藜科、石竹科等 2 0余科植物不能或不易形成ＡＭ外 ,大多数植物包括苔藓、蕨类、裸子植物、被子植物都能被菌根菌侵染。当前人们十分重视对野生植物上ＡＭ菌的调查[3 ,4 ,1 0 ,1 1 ,1 4 ]。研究发现 ,野生植物上可能有比栽培作物更多的ＡＭ菌种类[1 ]。我国野生植物资源丰富 ,开发和利用野生寄主植物上的ＡＭ菌潜力巨大。由于ＡＭ菌对寄主植物的选择性及对环境条件的适应性不同 ,或进化过程中的历史原因 ,造成了自然生态…