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1.
The intensification of the livestock production systems implies a potential environmental risk, associated with the great generation of animal wastes and slurries and their storage and management. Manure management is associated with considerable emissions of ammonia (NH3) and greenhouse gases (GHG). However, the potential for GHG mitigation is highly dependent on the waste treatment strategy considered. This laboratory study aims to evaluate the influence of the type of bulking agent used on the potential reduction of the carbon dioxide (CO2) emission, dealing with carbon (C) conservation when the solid fraction of pig (Sus scrofa domesticus) slurry is managed by composting. For this, a composting experiment in batch reactors was run with four mixtures elaborated using the solid fraction of pig slurry (SPS) and different materials (maize (Zea mays) stalks, barley (Hordeum vulgare L.) straw, cotton (Gossypium hirsutum) gin and garden prunings) as bulking agents. The potential C conservation in the mixtures was evaluated by determining the CO2 emissions; the evolution of the mixtures, the thermal profile developed and the thermodynamics of the process were also studied. The mixtures elaborated with cotton gin and garden prunings showed the fastest temperature development, and also the highest CO2 emissions. However, the use of maize stalks as bulking agent reduced CO2 emissions due to its slow degradability: this could constitute a suitable strategy to promote C conservation during the management of pig slurry by composting.  相似文献   

2.
Livestock [inclusive of ruminant species, namely cattle (Bos Taurus and Bos indicus), sheep (Ovis aries), goats (Capra hircus), and buffaloes (Bubalus bubalis), and non-ruminant species, namely pigs (Sus scrofa domesticus) and chickens (Gallus domesticus)] are both affected by climate change and contribute as much as 14.5 % of global anthropogenic greenhouse gas (GHG) emissions, most of which is from ruminant animals (Gerber et al. 2013). This study aims to estimate the marginal costs of reducing GHG emissions for a selection of practices in the ruminant livestock sector (inclusive of the major ruminant species—cattle, sheep, and goats) globally. It advances on previous assessments by calculating marginal costs rather than commonly reported average costs of abatement and can thus provide insights about abatement responses at different carbon prices. We selected the most promising abatement options based on their effectiveness and feasibility. Improved grazing management and legume sowing are the main practices assessed in grazing systems. The urea (CO(NH2)2) treatment of crop straws is the main practice applied in mixed crop–livestock systems, while the feeding of dietary lipids and nitrates are confined to more intensive production systems. These practices were estimated to reduce emissions by up to 379 metric megatons of carbon dioxide (CO2) equivalent emissions per year (MtCO2-eq yr?1). Two thirds of this reduction was estimated to be possible at a carbon price of 20 US dollars per metric ton of CO2 equivalent emissions ($20 tCO2-eq?1). This study also provides strategic guidance as to where abatement efforts could be most cost effectively targeted. For example, improved grazing management was particularly cost effective in Latin America and Sub-Saharan Africa, while legume sowing appeared to work best in Western Europe and Latin America.  相似文献   

3.
The objectives of this research are to assess the greenhouse gas mitigation potential of carbon policies applied to the ruminant livestock sector [inclusive of the major ruminant species—cattle (Bos Taurus and Bos indicus), sheep (Ovis aries), and goats (Capra hircus)]—with particular emphasis on understanding the adjustment challenges posed by such policies. We show that market-based mitigation policies can greatly amplify the mitigation potential identified in marginal abatement cost studies by harnessing powerful market forces such as product substitution and trade. We estimate that a carbon tax of US$20 per metric ton of carbon dioxide (CO2) equivalent emissions could mitigate 626 metric megatons of CO2 equivalent ruminant emissions per year (MtCO2-eq year?1). This policy would also incentivize a restructuring of cattle production, increasing the share of cattle meat coming from the multiproduct dairy sector compared to more emission intensive, single purpose beef sector. The mitigation potential from this simple policy represents an upper bound because it causes ruminant-based food production to fall and is therefore likely to be politically unpopular. In the spirit of the Paris Agreement (UNFCCC 2015), which expresses the ambition of reducing agricultural emissions while protecting food production, we assess a carbon policy that applies both a carbon tax and a subsidy to producers to manage the tradeoff between food production and mitigation. The policy maintains ruminant production and consumption levels in all regions, but for a much lower global emission reduction of 185 MtCO2-eq year?1. This research provides policymakers with a quantitative basis for designing policies that attempt to trade off mitigation effectiveness with producer and consumer welfare.  相似文献   

4.
Each of the last three decades has seen the Earth’s surface get progressively warmer more than any preceding decade since the 1850s. Greenhouse gas emissions from human activities have been scientifically demonstrated as the primary cause of the observed global climate change. The reduction of greenhouse gas levels in the atmosphere has deserved international attention. Aside from strategies to reduce emissions, increasing carbon storage by restoring and protecting destroyed forests has become an alternative method to lower carbon dioxide (CO2) levels. Therefore, effective restoration/conservation plans for deforested lands are urgently needed. The current work focuses on the restoration and conservation potential of destroyed Qinghai spruce (Picea crassifolia) forests in the Qilian Mountains of northwest China and provides a reasonable approach for drafting effective restoration/conservation plans for deforested lands. We first estimated habitat suitability of the Qinghai spruce using a habitat suitability model based on the relationships among the three most influential/significant environmental variables: average annual precipitation (P), average air temperature in July (T), and solar radiation (R) and the corresponding occurrence frequency of Qinghai spruce in the niche space. We then calculated the index of habitat suitability (IHS) for Qinghai spruce by applying a model in the study area. We finally used field data to classify the IHS map and identified the prior restoration and conservation areas for Qinghai spruce. The results show that (1) the optimal combination of T, P, and R for Qinghai spruce is 11.5 °C, 380 mm, and 2?×?103 kWh/m2, respectively; (2) these forests have potential for restoration; (3) areas with priority restoration and conservation potential are about 43 and 56.65 km2. The results of this study will help decision-makers develop and implement effective restoration/conservation strategies in the Qilian Mountains. This study presents a useful approach for helping decision-makers in other regions of the world draft effective restoration/conservation plans for deforested lands. The implementation of these plans will reduce CO2 concentration in the atmosphere, in turn, may retard global warming.  相似文献   

5.
利用IPCC的参考方法测算并比较分析了2005-2009年我国30个省(市、自治区)的CO2排放总量、人均排放量、排放强度、综合能源排放系数等重要指标,并在此基础上,依据人均GDP、第二产业比重和能源利用结构与碳排放强度的关系,将各省(市、自治区)划分为不同的CO2排放类型。研究结果表明,省域间各指标差异较大,影响碳排放的因素也不尽相同。省域减排的政策、途径和措施须充分考虑各自的经济发展水平、产业结构和能源利用结构等因素。  相似文献   

6.
Differences in functional traits between invasive and native plant species are believed to determine the invasion success of the former. Increasing amounts of anthropogenic nitrogen (N) are continually deposited into natural ecosystems, which may change the relative occurrence of the different N deposition forms (such as NH4–N, NO3–N, and CO(NH2)2–N) naturally deposited. Under high N deposition scenarios, some invasive species may grow faster, gaining advantage over native species. In a greenhouse experiment, we grew invasive and native Amaranthus species from seed both alone and in competition under simulated N enriched environments with different forms of N over 3 months. Then, we measured different leaf traits (i.e., plant height, leaf length, leaf width, leaf shape index, specific leaf area (SLA), and leaf chlorophyll and N concentrations). Results showed that the competition intensity between A. retroflexus and A. tricolor decreased under N deposition. This may be due to the large functional divergence between A. retroflexus and A. tricolor under simulated N deposition. Phenotypic plasticity of SLA and leaf chlorophyll concentration of A. retroflexus were significantly lower than in A. tricolor. The lower range of phenotypic plasticity of SLA and leaf chlorophyll concentration of A. retroflexus may indicate a fitness cost for plastic functional traits under adverse environments. The restricted phenotypic plasticity of SLA and leaf chlorophyll concentration of A. retroflexus may also stabilize leaf construction costs and the growth rate. Meanwhile, the two Amaranthus species possessed greater plasticity in leaf N concentration under NO3–N fertilization, which enhanced their competitiveness.  相似文献   

7.
In the late 1970s and for most of the 1980s, residential energy use in the OECD underwent significant changes. Many of these changes were a result of more efficient energy use in response to higher energy prices, energy efficiency programs, and the appearance of new technologies for saving energy. This study analyzes these changes and the impact of energy use on carbon emissions in the residential sector for nine OECD countries for the period from 1973 to 1992. The major findings of this analysis are:
  1. CO2 emissions per capita were lower in 1992 in almost all of the countries we studied;
  2. The two primary changes were improvements in energy efficiency and a decrease in the share of fossil fuels used for electricity and district heating production;
  3. The main source of growth in emissions from residential energy use was increased ownership of electric appliances, where, in spite of important improvements in energy efficiency, ownership grew so rapidly that electricity use (and subsequent emissions) increased;
  4. Changes in fuel mix, including both the changes in the share of fuels used in households and the share of fuels used to generate electricity and district heating, led to a decrease in emissions in the nine countries;
  5. Increasing the efficiency of electric appliances and further reductions in the intensity of space heating are probably the key elements in a strategy to improve efficiency as a means to lowering CO2 emissions.
  相似文献   

8.
Chinese softshell turtles (Pelodiscus spp.) are widely distributed, ranging from the Amur and Ussuri Rivers in the Russian Far East through the Korean Peninsula, Japan, and eastern, central, and southern China to southern Vietnam. In East and Southeast Asia, Chinese softshell turtles are traditionally exploited for food and have been farm-bred in China since the Spring and Autumn Period, more than 2400 years ago. Currently, the annual production of Pelodiscus amounts to 340,000 t in China alone. Using mitochondrial DNA (2428 bp) and five nuclear loci (3704 bp), we examined broad sampling of wild and farm-bred Pelodiscus to infer genetic and taxonomic differentiation. We discovered four previously unknown mitochondrial lineages, all from China. One lineage from Jiangxi is deeply divergent and sister to the mitochondrial lineage of Pelodiscus axenaria. The nuclear loci supported species status for P. axenaria and the new lineage from Jiangxi. Pelodiscus maackii and P. parviformis, both harboring distinct mitochondrial lineages, were not differentiated from P. sinensis in the studied nuclear markers. The same is true for two new mitochondrial lineages from Zhejiang, China, represented by only one individual each, and another new lineage from Anhui, Guangdong, Jiangxi and Zhejiang, China. However, Vietnamese turtles yielding a mitochondrial lineage clustering within P. sinensis were distinct in nuclear markers, suggesting that these populations could represent another unknown species with introgressed mitochondria. Its species status is also supported by the syntopic occurrence with P. sinensis in northern Vietnam and by morphology. In addition, we confirmed sympatry of P. axenaria and P. parviformis in Guangxi, China, and found evidence for sympatry of P. sinensis and the new putative species from Jiangxi, China. We also discovered evidence for hybridization in turtle farms and for the occurrence of alien lineages in the wild (Zhejiang, China), highlighting the risk of genetic pollution of native stock. In the face of the large-scale breeding of Pelodiscus, we claim that the long-term survival of distinct genetic lineages and species can only be assured when an upscale market segment for pure-bred softshell turtles is established, making the breeding of pure lineages lucrative for turtle farms. Our findings underline that the diversity of Pelodiscus is currently underestimated and threatened by anthropogenic admixture. We recommend mass screening of genetic and morphological variation of Chinese softshell turtles as a first step to understand and preserve their diversity.  相似文献   

9.
Biological invasions have incurred serious threats to native ecosystems in China, and soil N-fixing bacteria communities (SNB) may play a vital role in the successful plant invasion. Meanwhile, anthropogenic acid deposition is increasing in China, which may modify or upgrade the effects that invasive plant species can cause on SNB. We analyzed the structure and diversity of SNB by means of new generation sequencing technology in soils with different simulated acid deposition (SAD), i.e., different SO4 2? to NO3 ? ratios, and where the invasive (Amaranthus retroflexus L.) and the native species (Amaranthus tricolor L.) grew mixed or isolated for 3 months. A. retroflexus itself did not exert significant effects on the diversity and richness of SNB but did it under certain SO4 2? to NO3 ? ratios. Compared to soils where the native species grew isolated, the soils where the invasive A. retroflexus grew isolated showed lower relative abundance of some SNB classes under certain SAD treatments. Some types of SAD can alter soil nutrient content which in turn could affect SNB diversity and abundance. Specifically, greater SO4 2? to NO3 ? ratios tended to have more toxic effects on SNB likely due to the higher exchange capacity of hydroxyl groups (OH?) between SO4 2? and NO3 ?. As a conclusion, it can be expected a change in the structure of SNB after A. retroflexus invasion under acid deposition rich in sulfuric acid. This change may create a plant soil feedback favoring future A. retroflexus invasions.  相似文献   

10.
采用IPCC温室气体排放清单中CO2排放因子与估算方法,核算了1995—2012年中国30个省区(不含港澳台地区和西藏自治区数据,全文同)服务业的CO2排放量,并对30个省区服务业人均CO2排放量的时空特征进行分析;利用基于面板数据的EKC模型检验中国及其三大经济带服务业增长与CO2排放之间的关系. 结果表明:在考察期内,中国服务业人均CO2排放量从0.16 t升至0.77 t,服务业人均增加值从1 621.04元增至9 991.95元;服务业人均CO2排放量排在前列的省区大都位于东部地区;东部和中部地区人均CO2排放量与服务业人均增加值之间呈线性正相关,人均服务业增加值每增加1个单位,人均CO2排放量将分别增加1.02和1.16个单位;西部地区人均CO2排放量与服务业人均增加值之间呈单调递增关系. 在此基础上,提出差别化的碳减排对策:①东部地区应通过技术改进和优化产业结构、能源消费结构来降低CO2排放,并成为中国服务业节能减排的“领头羊”;②中、西部地区应在保持服务业经济适当增速的前提下,将提高能源利用效率和降低能源强度作为减排重点.   相似文献   

11.
12.
Males and females are often subjected to different selection pressures for homologous traits, resulting in sex-specific optima. Because organismal attributes usually share their genetic architectures, sex-specific selection may lead to intralocus sexual conflict. Evolution of sexual dimorphism may resolve this conflict, depending on the degree of cross-sex genetic correlation (r MF) and the strength of sex-specific selection. In theory, high r MF implies that sexes largely share the genetic base for a given trait and are consequently sexually monomorphic, while low r MF indicates a sex-specific genetic base and sexual dimorphism. Here, we broadly test this hypothesis on three spider species with varying degrees of female-biased sexual size dimorphism, Larinioides sclopetarius (sexual dimorphism index, SDI?=?0.85), Nuctenea umbratica (SDI?=?0.60), and Zygiella x-notata (SDI?=?0.46). We assess r MF via same-sex and opposite-sex heritability estimates. We find moderate body mass heritability but no obvious patterns in sex-specific heritability. Against the prediction, the degree of sexual size dimorphism is unrelated to the relative strength of same-sex versus opposite-sex heritability. Our results do not support the hypothesis that sexual size dimorphism is negatively associated with r MF. We conclude that sex-specific genetic architecture may not be necessary for the evolution of a sexually dimorphic trait.  相似文献   

13.
14.
The objectives of this work are to use gene sequence data to assess the hypothesis that the Lithodinae arose from ancestors with uncalcified abdomens in shallow waters of the North-East Pacific, investigate the monophyly and interrelationships of genera within the Lithodinae and to estimate the scale and minimum number of biogeographic transitions from the shallow environment to the deep sea and vice versa. To do this, phylogenetic analysis from three mitochondrial and three nuclear markers was conducted using minimum evolution, maximum likelihood and Bayesian methods. The Lithodinae as defined to include North Pacific genus Cryptolithodes may be paraphyletic, with the Hapalogastrinae and Cryptolithodes as sister taxa. This implies that the soft-bodied abdomen of the Hapalogastrinae might not be plesiomorphic for the Lithodidae. Paralomis, Lopholithodes, Phyllolithodes, Lithodes and Neolithodes share a common ancestor, from which the North Pacific Hapalogastrinae did not descend. Lithodid ancestors are likely to have had a north Pacific, shallow water distribution and to have had planktotrophic larvae. North Pacific genus Paralithodes is paraphyletic; P. brevipes is the most basal member of the genus (as sampled) while P. camtschaticus and P. platypus are more closely related to the genera Lithodes and Neolithodes. Genera Lithodes, Neolithodes and Paralomis (as sampled) are monophyletic if Glyptolithodes is included within Paralomis. Lopholithodes is closely related to, but not included within, the Paralomis genus. Paralomis is divided into at least two major lineages: one containing South Atlantic, West African, and Indian Ocean species, and the other containing Pacific and South American species. Several species of Paralomis do not resolve consistently with any other groups sampled, implying a complex and possibly rapid global evolution early in the history of the genus. Relationships within the Lithodes genus vary between analytical methods, suggesting that conclusions may not be stable. Consistently, however, Indian Ocean and Pacific forms—L. murrayi, L. longispina and L. nintokuae form a group separated from Atlantic species such as L. santolla, L. confundens, L. maja and L. ferox.  相似文献   

15.
基于LMDI中国省域氮氧化物减排与实现路径研究   总被引:1,自引:0,他引:1  
王丽琼 《环境科学学报》2017,37(6):2394-2402
首先基于Kaya恒等式,利用对数平均Divisia指数分解模型(LMDI法)将氮氧化物排放分解为排放因子、能源强度、经济结构、能源结构和经济发展5个因素;其次通过模型得出的脱钩系数运用构建四象限法评价"十二五"期间中国30个省市脱钩空间差异,研究各省市氮氧化物减排表现、分析减排潜力和减排影响因素,为国家"十三五"制定差异化的区域氮氧化物减排目标和寻找多元化的氮氧化物减排途径提供有益参考.研究结果表明:经济增长是促进氮氧化物排放量增加的决定因素,能源强度降低是抑制氮氧化物增排的决定因素,经济结构优化和能源结构调整具有较大促进氮氧化物减排潜力;中国氮氧化物排放与经济增长脱钩空间分异明显,大部分省市经济发展与氮氧化物排放处于脱钩状态,部分省市弱脱钩状态.同时,中国氮氧化物排放与经济增长脱钩系数呈现逐年上升趋势,2010—2015年中国各省市氮氧化物排放脱钩空间分布由较弱、中脱钩为主至中、较强脱钩为主再到较强脱钩为主,呈现区域间"异质化"和区域内"均质化"的趋势.国家氮氧化物后续减排任务应多分解在中脱钩或弱脱钩(减排潜力大)省市,对相邻的省份制定协同减排计划,且主要通过提高能源利用效率、同时优化经济结构和能源消费结构实现其最优减排.  相似文献   

16.
The antifungal potential of the pygidial gland secretion of the troglophilic ground beetle Laemostenus punctatus from a cave in Southeastern Serbia against cave-dwelling micromycetes, isolated from the same habitat, has been investigated. Eleven collected samples were analyzed and 32 isolates of cave-dwelling fungi were documented. A total of 14 fungal species were identified as members of the genera Aspergillus, Penicillium, Alternaria, Cladosporium, Rhizopus, Trichoderma, Arthrinium, Aureobasidium, Epicoccum, Talaromyces, and Fusarium. Five isolates were selected for testing the antifungal activity of the pygidial gland secretion: Talaromyces duclauxi, Aspergillus brunneouniseriatus, Penicillium sp., Rhizopus stolonifer, and Trichoderma viride. The microdilution method has been applied to detect minimal inhibitory concentrations (MICs) and minimal fungicidal concentrations (MFCs). The most sensitive isolate was Penicillium sp., while the other isolates demonstrated a high level of resistance to the tested agent. L. punctatus has developed a special mechanism of producing specific compounds that act synergistically within the secretion mixture, which are responsible for the antifungal action against pathogens from the cave. The results open opportunities for further research in the field of ground beetle defense against pathogens, which could have an important application in human medicine, in addition to the environmental impact, primarily.  相似文献   

17.
We applied a multi-isotope approach to examine aspects of niche partitioning, competition, and mobility for rodents in the Central Highlands of Madagascar. Specifically, we used carbon (δ13C), nitrogen (δ15N), and strontium (87Sr/86Sr) isotope ratios in bone to investigate diet and mobility for endemic tufted tail rats (Eliurus spp.), and introduced black rats (Rattus rattus) and house mice (Mus musculus) within and outside a fragment of montane humid forest in the Ambohitantely Special Reserve. There was a clear spatial segregation in trapping success for different species: Eliurus was only in the forest interior and edge, Mus only outside of the fragment in a marsh and park housing complex, and Rattus in all habitats except the housing complex. We find only moderate support for mobility of rodents among habitats. Mus may routinely move between the marsh and housing complex. However, regular movement between the forest edge and interior, or between the forest fragment and surrounding grassland is not supported. Taxa appear to target different foods: Rattus tends to feed at a higher trophic level than Eliurus, and Mus consumes some C4 resources. To date, strontium isotopes have been underutilized in ecological research. Here, we show that they are highly complementary to carbon and nitrogen isotope data. Even in localities with relatively uniform underlying geology, it may be possible to distinguish individuals that regularly forage in different habitats.  相似文献   

18.
中国水泥工业CO2排放现状及减排对策   总被引:2,自引:0,他引:2  
水泥工业是中国制造业中温室气体CO2的主要排放源,因此,根据水泥生产的基本原理和工艺特点,建立了CO2排放的数学模型并确定排放强度,计算了2001—2010年中国水泥工业CO2的排放量,分析了影响CO2排放量的主要因素及其发展趋势,并提出水泥工业CO2减排对策.结果表明,中国水泥工业CO2排放总量逐年增长,与水泥产量和单位产品原料、燃料消耗定额呈线性关系;在CO2排放总量中,原料煅烧和燃料燃烧阶段的排放量分别占49%和51%;"十一五"期间单位水泥产品CO2排放强度由0.69t.t-1下降到0.65t.t-1.万元GDPCO2排放量呈下降趋势,2008年达到最低值为0.3054t,平均每年万元GDPCO2排放量下降10.69%,说明水泥工业10年间实施节能降耗、资源循环利用、提高经济效益等措施对于减少CO2排放具有明显效果.  相似文献   

19.
Flower symmetry is considered a species-specific trait and is categorized in asymmetry, actinomorphic symmetry, bisymmetry and zygomorphic symmetry. Here we report on the intra-individual variation of flower symmetry in the genus Saxifraga and the influence of light, gravity and intrinsic factors on the development of flower symmetry. We tested five species—Saxifraga cuneifolia, Saxifraga imparilis, Saxifraga rotundifolia, Saxifraga stolonifera and Saxifraga umbrosa—concerning six flower parameters—angles between petals, petal length, petal pigmentation, angular position of carpels, movement of stamens and (only for S. imparilis and S. stolonifera) the length of the two lower elongated petals in regard to their position towards the stem. Specimens of all species were tested on a vertical clinostat as a gravity compensator, on a horizontal clinostat as a light incidence compensator and on a stationary control. The results show that the angle of incident light has no apparent impact on flower symmetry, whereas gravity affects the angular position of petals in S. cuneifolia and S. umbrosa and the petal colouration in S. rotundifolia. In S. cuneifolia and S. umbrosa, the absence of directional gravity resulted in the development of actinomorphic flowers, whereas the corresponding control flowers were zygomorphic. The development of flowers in S. rotundifolia was not altered by this treatment. The length of the two elongated petals in S. stolonifera and S. imparilis was not affected by gravity, but rather was determined by position of the flower within the inflorescence and resulted in asymmetrical flowers.  相似文献   

20.
To confirm whether the amplitude of diel temperature cycles causes a phase shift of adult eclosion rhythm of the onion fly, Delia antiqua, the peak time (Ø E) of adult eclosion was determined under various thermoperiods with a fixed temperature either in the warm or cool phase and temperature differences ranging from 1°C to 4°C between the two phases. Irrespective of the temperature level during the warm or cool phase, Ø E occurred earlier with decreasing amplitude of the temperature cycle. The results strongly support the previous conclusion of Tanaka and Watari (Naturwissenschaften 90:76–79, 2003) that D. antiqua responds to the amplitude of temperature cycle as a cue for the circadian adult eclosion timing. The phase advance was larger in thermoperiods with a fixed warm-phase temperature than in those with a fixed cool-phase temperature. This might be ascribed to the interaction between the amplitude and level of temperature in the thermoperiodic regimes.  相似文献   

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