我国脱硝市场的现状及发展建议

我国脱硝市场任务艰巨,政策扶持将催生爆发性机遇。脱硝产业目前存在缺乏具有自主知识产权的核心技术、绝大多数单位依靠引进技术、市场竞争处于无序状态等问题;提出了发展脱硝市场的应对措施,建议建立市场准入制度和经济补贴政策,加强排放标准制订工作。     

Bumblebee Vulnerability: Common Correlates of Winners and Losers across Three Continents

Abstract:  It is widely agreed that in many parts of the world some bumblebee ( Bombus ) species have declined, and that this has often been driven by land-use changes that cause reductions in the abundance of food plants. There is much less agreement about how changes in food plants affect some bumblebee species more than others. We sought to identify which species' characteristics are generally associated with the relative winners and losers by comparing the 3 independent bumblebee faunas from parts of Britain, Canada, and China. Using available survey data, we assessed species characteristics, including competition with congeners, climatic specialization, proximity to climatic range edge, food specialization, phenology, body size, and range size. Results of our meta-analysis of correlations showed support for the hypotheses that decline susceptibility is generally greater for species that have greater climatic specialization, for species in areas where they occur closest to the edges of their climatic ranges, and for species that have queens that become active later in the year. The latter characteristic may render a species at a particular disadvantage when they have long colony cycles if there are losses of food plants in mid to late colony development.     

长江流域冬季农业主要作物的耕地竞争机制及案例研究

长江流域是世界最大的油菜籽生产带，增加油菜籽种植面积和产量是提高我国油料供给能力的重要方面。在该区域，油菜籽和小麦是最主要的冬季农作物，也是具备耕地竞争关系的2种主要作物。在对长江流域这两种作物的耕地竞争机制进行理论分析的基础上，系统阐述了耕地竞争力各影响因素之间的内在联系；根据实地调查的数据与结果，对油菜籽和冬小麦的耕地竞争关系进行深入分析。研究结果显示：油菜籽耕地竞争力的影响因素主要有单产、收购价格、机械化水平、劳动力价格及国家政策；稳定油菜籽收购价格是提高油菜籽耕地竞争力的关键；随着农村劳动力成本的提高，油菜籽生产的机械化水平成为影响种植效益的重要因素；国家补贴的影响作用不大。另外，结论也表明长江流域存在很大的油菜籽生产潜力。     

Sewage sludge ditch for recovering heavy metals can improve crop yield and soil environmental quality

• Indirect use of sludge in ditches alongside plants was tested in field experiments. • The dried and stabilized sludge in ditches was recovered with heavy metals. • Cd, Pb, Cu and Zn in the planted soil were all in a safe range. • The indirect use of sludge increased plant yield, soil N content and C storage. The treatment and disposal of municipal sewage sludge (MSS) is an urgent problem to be resolved in many countries. Safely using the nutrients within MSS to increase crop yield and enhance the fertility of poor soil could contribute to achieving sustainable development. An indirect use of MSS in ditches alongside Pennisetum hybridum plants was studied in field plots for 30 months and the contents of heavy metals and macronutrients were monitored in soil, sludge and plant samples. We found that the yield of P. hybridum was significantly increased by 2.39 to 2.80 times and the treated plants had higher N content compared with no sludge. In addition, the organic matter (OM) and N contents in the planted soil increased significantly compared with the initial soil. The OM content in the planted soil of the MSS treatment was 2.9 to 5.2 times higher than that with no sludge, and N increased by 2.0 to 3.8 times. However, MSS had no significant effect on the N, P and K contents in the soil at the bottom of the MSS ditch, and the content of heavy metals (Cd, Pb, Cu and Zn) were also within the safe range. Moreover, the moisture content and phytotoxicity of MSS after this indirect use were reduced and the heavy metal contents changed little, which is favorable to the further disposal of recovered MSS. Therefore, this indirect use of MSS is beneficial to agricultural production, soil quality and environmental sustainability.     

林下和撂荒地生境紫茎泽兰幼苗的生长特征及其种内竞争形态反应

比较研究了林下和撂荒地生境有无竞争条件下紫茎泽兰（Ageratina adenophora（Sprengel））幼苗的生长特征、生长速率、生物量和种内竞争的形态反应。结果表明：（1）2类生境条件下紫茎泽兰植株幼苗形态特征基本一致,无竞争条件下紫茎泽兰幼苗根长和叶片数明显高于在竞争条件下对应指标值;（2）同类生境中,在无竞争条件下紫茎泽兰幼苗的生长速率、生物量积累显著比在竞争条件下的高;（3）不同生境中,撂荒地生境紫茎泽兰幼苗生物量显著高于林下生境的值,在无竞争条件下,林下生境紫茎泽兰幼苗生长速率比撂荒地生境的高,而在竞争条件下反之;（4）林下和撂荒地生境紫茎泽兰幼苗植株竞争强度差异不显著,但在林下生境其地上部分的竞争强度显著大于其在撂荒地生境的值,而根的竞争强度相反。可见,紫茎泽兰幼苗在种群建立的过程中具有不同的生态适应性和形态反应,这可能是其能成功入侵不同生境的一种重要生理生态策略。     

Cannibalize or care? The role of perceived paternity in the sand goby, <Emphasis Type="Italic">Pomatoschistus minutus</Emphasis>

Parental care is a costly part of reproduction. Hence, natural selection should favor males which avoid caring for unrelated young. However, the decision to abandon or reduce care requires cues which are evaluated to give information on potential reproductive value of the offspring. The prediction that male sand gobies, Pomatoschistus minutus, care for foreign eggs as long as they were spawned in their own nest and at least some of such cues are fulfilled was tested. Egg-guarding males that had recently taken part in a spawning event were given a clutch of eggs that was sired either by themselves or another male, in either their own or another male’s aquarium. Males that had not taken part in a spawning event were used as controls and were given eggs sired by another male. We measured the amount of filial cannibalism and nest building. Control group males did not care for eggs and ate them all before rebuilding the nest. In the other treatments, there were no significant effects of paternity, though males moved to another male’s aquarium increased their clutch area threshold and completely consumed larger clutches than males that were not moved. There was no intermediate response in any treatment in the form of increased partial filial cannibalism or less well-constructed nests. Our results suggest that egg-guarding males cannot distinguish between eggs sired by themselves and those sired by other males but are able to react to cues indicating paternity state. Males do not adopt eggs to attract females in P. minutus.     

Advertisement-call modification,male competition,and female preference in the bird-voiced treefrog <Emphasis Type="Italic">Hyla avivoca</Emphasis>

Senders and receivers influence dynamic characteristics of the signals used for mate attraction over different time scales. On a moment-to-moment basis, interactions among senders competing for a mate influence dynamic characteristics, whereas the preferences of receivers of the opposite gender exert an influence over evolutionary time. We observed and recorded the calling patterns of the bird-voiced treefrog Hyla avivoca to assess how the dynamic characters of calls vary during interactions among groups of males in a chorus. This question was also addressed using playback experiments with males. Playback experiments with females showed how changes in dynamic call properties are likely to affect male mating success. Frogs calling in pairs, groups, or in response to playbacks produced longer calls than did isolated males. During call overlap, males often increased the duration of the silent interval (gaps) between the pulses of their calls so that the pulses of the calls of two neighbors interdigitated. This change resulted in increased variability of pulse rate, a traditionally static acoustic property; however, males also produced high proportions of non-overlapped calls in which variability in pulse rate was low and had species-typical values. Females preferred long calls to short- and average-duration calls, and non-overlapped calls to overlapped calls. Given a choice between pairs of overlapped calls, females preferred pairs in which the proportion of overlap was low and pairs in which the pulses of such calls interdigitated completely. The observed patterns of vocal competition thus reflect the preferences of conspecific females, which have influenced the evolution of the calling behavior of H. avivoca. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Predicting the mating system from phenotypic correlations between life-history and sperm quality traits in the Alpine whitefish <Emphasis Type="Italic">Coregonus zugensis</Emphasis>

The mating behavior and reproductive strategies of Alpine whitefish like Coregonus zugensis (Nüsslin) are poorly understood, probably because they spawn in deep water where direct observations are difficult. In this study, we interpret life-history and sperm quality traits of fish that we caught from their spawning place. We found that males invest heavily into gonadal tissue (up to 5.6% of their body weight), which is, in comparison to other fish, consistent with external fertilization, distinct pairing and moderate to high communal spawning, or no pairing and low to moderate communal spawning. Sperm competition theory and recent experimental studies on other salmonids predict that males optimize ejaculate characteristics in relation to the costs of sperm and the level of competition they have to expect: dominant males are predicted to invest less into ejaculate quality and to have slower spermatozoa than subdominant males. We found that spermatozoa of older males are slower than those of younger males. Moreover, older males have larger breeding tubercles, a secondary sexual trait that has, in some previous studies, been found to be linked to good condition and to good genetic quality. Our results suggest that C. zugensis has age-linked reproductive strategies, that multimale spawning is common, i.e., that sperm competition plays a significant role, and that older males are on average dominant over younger males at the spawning place.     

Exploring the administrative mechanism of China's Paired Assistance to Disaster Affected Areas programme

The Paired Assistance to Disaster Affected Areas (PADAA) programme is a mutual aid initiative with Chinese characteristics, which speeded up the process of restoring and reconstructing regions affected by the Wenchuan earthquake on 12 May 2008. 1 The PADAA is an efficient instrument for catastrophe recovery, yet it remains a mysterious mechanism to many members of disaster management communities. This paper aims to lift the veil on it by assessing its origins and evolution. It draws on the multi‐level moderated competition model to explain how the PADAA functions within the Chinese administrative system. The country's top‐down political system allows the central authority to mandate provincial and local governments from more economically developed regions to assist devastated areas with post‐disaster reconstruction. The practices of local accountability complement vertical control by giving leaders from donor regions strong incentives to accomplish assigned reconstruction tasks, resulting in intense competition between them.