Modelling recruitment dynamics of hake, Merluccius merluccius, in the central Mediterranean in relation to key environmental variables

Hake recruitment has been examined in relation to environmental variables in two of the main reproductive areas of the central Mediterranean, the northern and central Tyrrhenian Sea. Seventeen years time series data from trawl surveys revealed high fluctuations in recruit abundance that could not be just explained by spawning biomass estimations. Generalized additive models were developed to investigate hake recruitment dynamics in the Tyrrhenian Sea in relation to spawner abundance and selected key oceanographic variables. Environmental data were explored in attempt to explain survival processes that could affect early life history stages of hake and that accounted for high fluctuations in its recruitment.Thermal anomalies in summer, characterised by high peaks in water temperature, revealed a negative effect on the abundance of recruits in autumn, probably due to a reduction in hake egg and larval survival rates. In the northern Tyrrhenian, recruitment was reduced when elevated sea-surface temperatures were coupled with lower levels of water circulation. Enhanced spring primary production, related to late winter low temperatures could affect water mass productivity in the following months, thus influencing spring recruitment. In the central Tyrrhenian a dome-shaped relationship between wind mixing in early spring and recruitment could be interpreted as an “optimal environmental window” in which intermediate water mixing level played a positive role in phytoplankton displacement, larval feeding rate and appropriate larval drift. Results are discussed in relation to the decline in hake stock biomass and within the present climate change and global warming context.     

基于体制转轨背景下的区域发展研究——以河南省为例

研究了河南省在经济体制转轨的背景下实施可持续发展过程中面临的人口、资源和环境等问题,分析了阻碍可持续发展的因素,研究了解决问题的途径,明确了可持续发展的核心是人,可持续发展是经济与环境相协调的发展,以期能够为河南省的发展提供借鉴。     

环境系统分析课程教学过程的思考与改革探索

该文在总结环境系统分析课程基本特点的基础上，针对苏州科技学院环境科学专业本科培养目标和特色，结合教学实践，提出“挖掘学习兴趣、创造实践机会、灌输环保理念”的教学思路，希望为进一步提高该专业人才培养质量提供参考。     

Quantifying the Impact Factors of Different Forms of Potassium and Absorptions by Different Cotton Genotypes

This study focuses on two genotypes of cotton and explores different factors that were able to affect the release of different forms of potassium (K) in the rhizosphere by considering a biogeochemical process integrating plants, soils, and microorganisms. The study indicated that both genotypes of cotton could effectively absorb exchangeable potassium (eK) under limited potassium (LK) supply, and cotton plants could use LK to sustain offspring, preferably under K-deficiency conditions. It was mainly due to its significantly greater active absorbing surface area of root and comparatively greater K⁺ maximum uptake rate (I_max), which caused more K accumulation in the high-efficiency genotype cotton (HEG). Although I_max of the low-efficiency genotype cotton’s (LEG’s) was greater, K accumulation in LEG was less, which might be attributed to its significantly lower HEG and feedback inhibition on K taken up by greater K concentration in the plant. The lint yield had a significant positive correlation with boll number per plant, single boll weight, plant height, and number of fruit branches, which indicated that increasing these agronomic parameters is the base for increasing lint yield. There was a synergic action among humus, microorganisms, and K in the rhizosphere soil. The cation exchange capacity (CEC) of reduced soils was less under oxidized condition, due to collapse of the interlayer in response to increased layer charge upon structural Fe reduction. Crop yields can be increased when fertilizer K is applied according to proper ratio among different forms of potassium and humic acid in soils. The middle-high plant height, lower initial fruit branch, more fruit branches, more bolls, and larger boll size should receive more attention during high-yielding cotton breeding.     

区域环保产业发展现状分析与对策研究——以云南省为例

环保产业是区域及国家环境保护的重要基础和技术保障,已成为国民经济发展中最具潜力的新的经济增长点之一.本文以云南省为例,基于区域环保产业的发展动力、规模扩大、产业结构优化,探讨了地方环保产业发展的集群模式.文章结合云南省资源开发与生态保护并进的需求,指出了云南省在清洁技术与产品研发、资源综合利用、土壤修复和环保服务业等环保产业领域发展的对策和建议,为推动区域及我国环保产业发展提供参考.     

基于养分平衡和环境保护的北京市城市结构探讨

城市化进程中,随着人口不断向城市积聚,城市成为各种农产品的输入地,农民也不断增加对城市周围耕地的投入以获取更多的农产品。城市及其郊区成为各种物流、能流的聚集地。如果聚集的能量、养分得不到有效利用,不仅造成资源的浪费,还会给环境带来一定的压力。文章基于养分循环原理,以北京市为例,对分别计算了北京市人畜排泄物和作物产出可以提供的养分,与北京市耕地在吨粮田情况下所能够吸纳的养分,结果显示养分是富余的。与单中心大城市相比,多中心中小城市的城市建成区与周围农田之间的物流能流交换界面更大,有利于充分利用人畜排泄物作为作物养分,发展有机农业;同时,也有利于减少城市环境压力和改善城市生态环境。因此,要坚持分散集团式的城市空间布局,避免"城市大饼"无限扩大,促进养分循环和土地可持续利用,建设生态环境良好的宜居城市。     

Glyphosate effects on photosynthesis,nutrient accumulation,and nodulation in glyphosate‐resistant soybean

Previous greenhouse studies have demonstrated that photosynthesis in some cultivars of first‐ (GR1) and second‐generation (GR2) glyphosate‐resistant soybean was reduced by glyphosate. The reduction in photosynthesis that resulted from glyphosate might affect nutrient uptake and lead to lower plant biomass production and ultimately reduced grain yield. Therefore, a field study was conducted to determine if glyphosate‐induced damage to soybean (Glycine max L. Merr. cv. Asgrow AG3539) plants observed under controlled greenhouse conditions might occur in the field environment. The present study evaluated photosynthetic rate, nutrient accumulation, nodulation, and biomass production of GR2 soybean receiving different rates of glyphosate (0, 800, 1200, 2400 g a.e. ha^–1) applied at V2, V4, and V6 growth stages. In general, plant damage observed in the field study was similar to that in previous greenhouse studies. Increasing glyphosate rates and applications at later growth stages decreased nutrient accumulation, nodulation, leaf area, and shoot biomass production. Thus, to reduce potential undesirable effects of glyphosate on plant growth, application of the lowest glyphosate rate for weed‐control efficacy at early growth stages (V2 to V4) is suggested as an advantageous practice within current weed control in GR soybean for optimal crop productivity.     

沼气工程对畜禽粪便污染环境成本的控制效果

沼气工程是治理畜禽粪便污染的主要方法,可提供清洁能源,减少温室气体排放,减轻环境污染,具有良好的环境效益。本研究以湖南省洞庭湖区为例,利用《气候变化框架公约》清洁机制执行理事会批准的方法(ACM0010)和环境成本估算方法,分析了沼气工程对畜禽粪便污染的环境成本的控制潜力。结果表明,在湖南省洞庭湖区的畜禽粪便均采用沼气项目进行污染治理条件下,年出栏5 000头以上的生猪规模养殖场均进行沼气发电,其他畜禽养殖场的沼气全部用于畜禽养殖场及周边居民的供热和照明使用,则2006年可减排温室气体2 891 614 t CO2当量,减少温室气体排放环境成本为4.52亿元;同时,可减排水体污染、土壤污染、微生物污染控制的环境成本分别为4.56亿元、1.69亿元、5.32亿元。因此,要支持和鼓励养殖户利用沼气工程处理畜禽粪便,实现畜禽粪便污染治理环境效益、经济效益和社会效益的有机统一。     

土壤冻融作用对植物生理生态影响研究进展

土壤冻融作用是季节性冻土区和多年冻土区常见的自然现象,主要是指由于土壤温度变化而出现的反复冻结解冻过程。冻融作用不仅影响土壤的理化和生物学性质,而且还会改变植物的生理生态过程,从而可能对冻土广泛分布的高纬度和高海拔地区植被生态系统生产力产生重要影响。本文重点论述了土壤冻融对植物地上和地下部分生理生态过程的影响效应以及全球变化背景下高寒植被生态系统对不同冻融格局的响应特征,总结了不同气候环境条件及生境胁迫下植物光合作用、生物量和生产力、根系生长及其对水分和温度胁迫响应等的生理生态表现,同时对当前土壤冻融与植物生理生态领域研究存在的不足进行了阐释,提出全球变化背景下频繁的土壤冻融作用将强烈改变植被生态格局和功能,并指出这种改变在高寒生态系统中表现将更为显著。     

Grassland and globalization – challenges for north‐west European grass and forage research

The concept of sustainable intensification has recently been developed to raise productivity (as distinct from increasing volume of production) while reducing environmental impacts. This means increasing yields per unit of inputs (including nutrients, water, energy capital and land) as well as per unit of undesirable outputs (such as greenhouse gas emissions, water pollution or loss of biodiversity). It is thus helpful to understand ‘intensification’ as referring to ‘environmental factor productivity’ or ‘eco‐efficiency’. Worldwide, grassland is the most important agroecosystem delivering ecosystem services ranging from feed supply for ruminants and soil carbon storage to habitats of biodiversity. However, worldwide, grassland is under threat due to intensified land use and land‐use changes from grass to arable. In this article, we (i) highlight ecosystem services of selected grassland biomes abroad of Europe, (ii) show evidence of sustainable as well as non‐sustainable intensification options in these grassland biomes linked to European agriculture by exports of agricultural commodities (e.g. soy) and (iii) derive research strategies for north‐west European grassland research and management to match sustainable intensification strategies for the grassland‐based dairy industry.