Comparison and analysis of agricultural and forest land changes in typical agricultural regions of northern mid-latitudes

The northeastern China, the United States, and the western Europe are important agricultural regions both on the global and regional scales. The western Europe has a longer history of agricultural land development than the eastern United States. These two regions have changed from the deforestation and reclamation phase in the past to the current land abandonment and reforestation phase. Compared with the two regions, large-scale land exploitation has only been practiced in the northeastern China during the last century. After a short high-intensity deforestation and reclamation period, agricultural and forest lands are basically in a dynamic steady state. By comparing domestic and international agro-forestry development and considering the ecological environment and socio-economic benefits that can be derived from agro-forestry, this paper suggests that large area of reforestation would be inevitable in future though persistent and large agricultural demand in coming decades even more. And local reforestation at slope farmland with ecological vulnerability should be imperative at present to avoid severer damage. At the same time, from the perspective of Land Change Science, the results demonstrate that the research on land use change in the agro-forestry ecotone is typical and critical, particularly those dealing with the analysis of spatial and temporal characteristics and the simulation of climate, hydrology, and other environmental effects.     

Large scale northward expansion of warm water species Skeletonema tropicum (Bacillariophyceae) in China seas

Skeletonema tropicum is regarded as a species with an affinity to warm waters and it has never been reported in seas where temperatures drop below 11°C in winter. Previous studies in China reported that S. tropicum was restricted to subtropical and warm temperate seas (East and South China Seas), but the species was recently found during August cruises of 2009 and 2010 in Jiaozhou Bay, Yellow Sea, located several hundred kilometers to the north. Here, winter water temperatures often drop below 5°C. Identification of S. tropicum was confirmed under light and scanning electronic microscopes and maximum cell abundance in Jiaozhou Bay was estimated as 1.73×10 4 cell/L. This record of S. tropicum in Jiaozhou Bay represents a significant northward expansion in the geographic range of the species. Ship ballast water was identified as a possible carrier of S. tropicum from southern places along Chinese coastline, and in addition, thermal pollution from local power stations and seawater desalination plants may provide suitable conditions for species over-wintering.     

The Relationships Between Toxicity,Species and Populations in Nassarius Based on Toxin Detection and Multiple Gene Barcoding

Nassarius causes many poisonings in China and other Asian countries. The toxicity of Nassarius is related to species and populations. However, the molecular assignment of different toxic Nassarius samples is still unclear, which deteriorates the poisoning. Our study combined toxicity, toxin detection and multiple genes DNA barcoding to assign the various toxic Nassarius species and populations from China coast. The toxicity test indicated that different Nassarius species and different populations within one Nassarius species had different toxicity. Based on High Performance Liquid Chromatography, the toxin was confirmed to be TTX. The toxin content varied in different samples. The COI, 16 S and ITS sequences revealed different toxic Nassarius species as monophyletic clades. All the samples tested have been assigned to species level. However, the different toxic populations within N. succinctus, N. variciferus and N. semiplicata did not form separated clades, and the toxic and nontoxic species did not form two clades separately. Our study constructed the relationship between toxicity and taxonomy assignment of different toxic Nassarius samples based on toxicity detection and multiple gene DNA barcoding, which provides the basis for controlling poisoning and studying the toxin-resistance difference in Mollusca. It is also indicated that the toxicity of Nassarius is really related with species at the genetic level, but not absolutely related with populations.     

中国北方农牧交错带土地沙化区典型植物的雨季水分来源

中国北方农牧交错带是中东部地区重要的生态安全屏障, 由于其系统结构脆弱、生态环境问题多发、土地沙化严重, 开展生态修复工作显得十分重要。植物-土壤水分关系作为土地沙化区生态水文过程的重要组成部分, 研究二者的转化过程对于了解植物吸水模式、确定生态修复的首选植物种非常关键。以河北省张家口市康保县北部为例, 基于雨季的大气降水、地下水、土壤水和植物水的氢氧同位素特征, 分析了主要植物的吸水层位、生态位宽度和水分竞争关系。结果表明, 柠条以吸收80~100 cm深度土壤水为主, 吸水比例最大可达87.7%, 油菜花以吸收0~20 cm深度土壤水为主, 吸水比例最大可达82.3%, 狼针的吸水层位与土壤含水率有关, 在含水率较高的深度吸水比例更大, 栉叶蒿的吸水深度较为均衡, 各植物种的生态位宽度均较大, 但部分植物间存在较强的水分竞争关系。本研究为中国北方农牧交错带土地沙化区的植物水源来源识别和生态修复提供了科学依据。      

First record of Paraonella platybranchia （Hartman, 1961） （Polychaeta： Paraonidae） from the Yellow Sea

This paper reports for the first time a species of polychaetous family Paraonidae, Paraonella platybranchia (Hartman, 1961), a rare species found previously only in the coast near the boundary between the United States and Mexico, and it was recently discovered in the samples collected in 1982 from Chinese side of the Yellow Sea. This is the first record of the species in China as well as in the Northwest Pacific.     

First record of <Emphasis Type="Italic">Paraonella platybranchia</Emphasis> (Hartman, 1961) (Polychaeta: Paraonidae) from the Yellow Sea

This paper reports for the first time a species of polychaetous family Paraonidae, Paraonella platybranchia (Hartman, 1961), a rare species found previously only in the coast near the boundary between the United States and Mexico, and it was recently discovered in the samples collected in 1982 from Chinese side of the Yellow Sea. This is the first record of the species in China as well as in the Northwest Pacific. Supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (No. O72715)     

PI3K/Akt/mTOR Signaling as Targets for Developing Anticancer Agents from Marine Organisms

The PI3 K/Akt/m TOR signaling pathway is one of the most frequently dysregulated pathways in cancer. Targeting the PI3 K-mediated pathway has been an important strategy for developing novel anticancer agents. In the past decades, more than 40 inhibitors of the PI3 K/Akt/m TOR pathway have been developed at different clinical stages. Temsirolimus, everolimus, idelalisib, and copanlisib have been approved for clinical use by the Food and Drug Administration of the United States(FDA). However, the toxicity and drug resistance limit their efficiency in the treatment. Novel compounds with greater potency and selectivity, as well as improved therapeutic indices with reduced toxicity, are clearly required. Over the past three decades, a lot of bioactive ingredients with anticancer effects by affecting the PI3 K-mediated pathways have been found from marine organisms. In the present mini-review, anticancer compounds from marine source that target the PI3 K/Akt/m TOR signaling were reviewed. The molecular entities and their modes of action were presented. The marine compounds targeting special factors of the PI3 K/Akt/m TOR were highlighted.     

Study of Panjin Wetlands Along Bohai Coast(Ⅱ):Ecological Water Requirement of Shuangtaizi Estuarine Wetland

Shuangtaizi estuarine wetland along the Bohai Sea coast,the biggest bulrush wetland in the world,has been listed in ‘The Record of Important International Wetland Conservation District’. Taking the year of 2 000 as an example,the minimum,the most suitable and the maximum ecological water requirement of Shuangtaizi estuarine wetland are calculated in this paper based on both ecological theory and Geological Information System technology. In addition,the remote sensing technique is adopted in the data acquisi...     

MORPHOLOGICAL COMPARISON OF THE FEEDING APPARATUS OF THREE CO-OCCURRING SPECIES OF PONYFISHES (LEIOGNATHIDAE)

ImOUocrON0verevoluti0narytirne,intetspeCiliccomPctitioncanresultincharactedisplacementSthatfadiitateresourcepartitioningamongspedesffeper,l985,Wilirarnanayake,l99O).Fisharenotablyopportunisticintheirfeding,toknowWhereandhowtheybowilloftenprovidemoreinsightintotheirerelogythansbolyknowingtheactUalcomPonentSoftheirdiet(Motta,l988,HUmPhrieS,l993).ArmrdinglymorphologicalcomParisonsamongcoxiccutwspchprovidemportantinfonnationnotonlytosySteInatistsfaedwithtaxonondcprobbo,butaIsot0erelogistS…     

Study of Panjin wetlands along Bohai coast (II): Ecological water requirement of Shuangtaizi estuarine wetland

Shuangtaizi estuarine wetland along the Bohai Sea coast, the biggest bulrush wetland in the world, has been listed in ‘The Record of Important International Wetland Conservation District’. Taking the year of 2 000 as an example, the minimum, the most suitable and the maximum ecological water requirement of Shuangtaizi estuarine wetland are calculated in this paper based on both ecological theory and Geological Information System technology. In addition, the remote sensing technique is adopted in the data acquisition process. Moreover, the total water requirement and the unit area water requirement for different wetland types are obtained. The result is very important for water resources planning, ecological conservation and regional agriculture structure adjustment in Shuangtaizi. Meanwhile, this study can serve as a useful example for calculating the ecological water requirement in other similar estuarine wetlands.     

Overview on seagrasses and related research in China

Seagrass research in China is still in its infancy. Even though there has been progress recently, there is still a great deal of research needed to gain a better understanding of seagrass. In this article we review and discuss the advances in seagrass research in China from two aspects: (1) seagrass species and their distribution; (2) seagrass research in China, including studies on their taxonomy, ecology, photosynthesis, applications in aquaculture, salt-tolerance mechanisms and other research topics. A total of 18 seagrass species belonging to 8 genera are distributed in nine provinces and regions in China (including Hong Kong and Taiwan), as well as the Xisha and Nansha Archipelagos. They can be divided into two groups: a North China Group and a South China Group. Based on the seagrass distribution, the Chinese mainland coast can be divided into three sections: North China Seagrass Coast, Middle China Seagrass Coast, and South China Seagrass Coast. Ecological studies include research on seagrass communities, nutrient cycling in seagrass ecosystems, genetic diversity, pollution ecology and research in the key regions of Shandong, Guangdong, Guangxi, and Hainan. Seagrass species and their locations, community structure, ecological evaluation, epiphytes, ecological functions and threats in the key regions are also summarized. Other studies have focused on remote sensing of seagrass, threatened seagrass species of China, and pollen morphology of Halophila ovalis.     

美国不动产征收典型案例分析及启示

美国宪法第五修正案规定不动产征收改变了以往封建社会不动产征收为统治阶级服务的目的而转向公共利益。但最初的制度设计随着政府角色定位改变、社会经济发展繁荣等多种因素难以充分应对公共政策制定和实施过程中遇到的各种问题。该文通过分析美国不动产征收权的形成背景及对其产生影响的典型案例,探析美国不动产征收权的形成与演化。结果表明,随着社会经济多元化发展以及公共用途内涵的不断扩展,美国政府通过案例来补充和完善法律在最初界定不动产征收相关条款的概括和不足。政府在行使不动产征收权的时候,虽然部分涉及与经营性用地结合来实现提高本地居民收入、增加就业机会和改善局部市政环境等目标,但如何协调政府行为与公共利益的关键在于建立合理的公共参与制度来反映公众诉求和监督政府行为,以实现个体权益保护的目的。美国不动产征收制度的演化与发展为我国征地制度改革提供了一定的理论借鉴和案例支撑。     

Variation of Zooplankton Ecological Group During Spring in China Estuaries

Zooplankton was major indicator species of the environment. To explore the effect of marine environment on zooplankton distribution in the coast of China, the zooplankton samples from stations in Guanhe Estuary(GE), Changjiang(Yangtze River) Estuary(CE), Oujiang Estuary(OE), Jiulongjiang Estuary(JE) and Beilun Estuary(BE)(covering 14 latitudes) in spring were surveyed and the variation of zooplankton ecological group was researched. According to the adaptability temperature, the zooplankton was divided into two ecological groups: warm-temperate species and subtropical species. The warm-temperate species was the main dominant species and subtropical species was only dominant species in BE. Calanus sinicus, a warm-temperate species, was the only dominant species in all five estuaries. From north to south, the proportion of warm-temperate species in the five estuaries gradually decreased depends on the number, were 83.33%, 48.39%, 45.00%, 43.75% and 30.43%, respectively. In contrary, the proportion of subtropical species was gradually increased. The warm-temperate species predominated over the total abundance and the percentage was whopping high in the north estuaries, including GE(96.16%), CE(95.57%), OE(97.83%) and JE(95.53%). The abundance percentage of subtropical species have remarkably higher(82.39%) in BE. Five estuaries zooplankton community was subdivided into three zooplankton groups, which were the northern warm temperate zooplankton group, the southern subtropical zooplankton group and the estuarine brackish-water group. The water temperature and coastal current of China Sea are recognized as the main factors determining the distribution and community structure of estuarine zooplankton in spring.     

Ecological risk assessment of heavy metals in surface seawater and sediment near the outlet of a zinc factory in Huludao City,Liaoning Province,China

At present, the methods widely applied to assess ecological risk of heavy metals are essentially single-point estimates in which exposure and toxicity data cannot be fully used and probabilities of adverse biological eff ects cannot be achieved. In this study, based on investigation of concentrations of six heavy metals (As, Hg, Pb, Cd, Cu, and Zn) in the surface seawater and sediment near the outlet of a zinc factory, located in Huludao City, Liaoning Province, China, a tiered approach consisting of several probabilistic options was used to refine ecological risk assessment for the individuals. A mixture of various heavy metals was detected in the surface seawater, and potential ecological risk index (PERI) was adopted to assess the potential ecological risk of heavy metals in the surface sediment. The results from all levels of aquatic ecological risk assessment in the tiered framework, ranging from comparison of single eff ects and exposure values to the use of distribution-based Hazard Quotient obtained through Monte Carlo simulation, are consistent with each other. Briefly, aquatic Zn and Cu posed a clear ecological risk, while Cd, Pb, Hg, and As in the water column posed potential risk. As expected, combined ecological risk of heavy metal mixture in the surface seawater was proved significantly higher than the risk caused by any individual heavy metal, calculated using the concept of total equivalent concentration. According to PERI, the severity of pollution by the six heavy metals in the surface sediment decreased in the following sequence: Cd>Hg>As>Pb>Cu>Zn, and the total heavy metals in the sediment posed a very high risk to the marine environment. This study provides a useful mathematical framework for ecological risk assessment of heavy metals.     

Application and comparison of two symptom-based eutrophication-assessment methods in Jiaozhou Bay,China

Increasing numbers of approaches to assess eutrophication,such as estuarine trophic status,the Oslo-Paris Commission Common Procedure,and the Water Framework Directive,focus on the symptoms of eutrophication.In China,however,nutrient index methods dominate the assessment of coastal waters.In this study,an integrated method that includes both water quality and ecological response was compared with the Northwest Pacific Action Plan(NOWPAP)Common Procedure.Observation data from Jiaozhou Bay,Shandong,China,were used in a comparison of the two methods in a trophic status study.Overall,both clearly revealed a high level of nutrient enrichment in the bay,indicated by high nutrient concentrations.Though the two methods differed in their methodological design in the assessment of the ecological effects of nutrient enrichment,they have acquired similar results:the integrated method suggested that the status was good,and the NOWPAP Common Procedure suggested that the status was low(indicating that the bay had no serious eutrophication problem).The introduction of filter feeders(shellfish aquaculture)into the bay on a reasonable scale may have been effective in mitigating eutrophic conditions,and perhaps explains the low ecological impacts there.Our results will be useful to ecosystem-based eutrophication management in the bay and in similar areas.     

Economic Value Evaluation of Wetland Service in Yeyahu Wetland Nature Reserve,Beijing

Based on multi-source data,this paper evaluated the economic value of ecological services in the Yeyahu Wetland Nature Reserve,Beijing,China.The ecological services of wetland included gas regulation,water quality im-provement,biodiversity maintenance,erosion control,water supply,recreational opportunity,raw material supply and existence value.Multiple conventional evaluation methods were used to calculate the value of eight wetland services.The results showed that significant values came from biodiversity ...     

西北地区生态环境建设中水资源可持续开发与管理的认识

西北地区水资源短缺，生态环境相当脆弱。随着西北地区大规模生态环境建设的实施，原来水资源的供需矛盾更为明显，处理好西北地区有限水资源中经济用水和生态用水的比例关系具有重要的意义。就西北地区的生态环境建设中水资源可持续开发和利用提出几点认识。     

Bacterial community shifts in different functional zones of a reservoir with ecological purification facilities

Ecological purification in a reservoir is an important strategy to control the level of nutrients in water.The bacterial community of such a reservoir is the main agent for pollutant degradation,which has not been fully documented.Taking the Jinze Reservoir,a freshwater source for Shanghai,China as the case,its spatial distributions of water and sediment bacteria were determined using 16 S rRNA gene-based Illumina MiSeq sequencing,and the environmental parameters were analyzed.The reservoir takes natural river water and functions as an ecological purification system,consisting of three functional zones,i.e.,pretreatment zone,ecological purification zone,and ecological sustaining zone.Results show that the concentrations of both total nitrogen(TN) and total phosphorus(TP) decreased considerably after the ecological treatment,and the concentration of dissolved oxygen(DO) in the ecological purification zone was boosted from that before pretreatment.In addition,patterns of bacterial communities in both water and sediment were similar and consisted of mainly Proteobacteria,Actinobacteria,and Bacteroidetes.However,difference in water bacterial composition was distinct in each functional zone,whereas the bacterial communities in sediment changed only slightly among sediment samples.Network analysis revealed nonrandom co-occurrence patterns of bacterial community composition in water and sediment,and Pseudomonas,unclassified Comamonadaceae,Variovorax,and Dechloromonas were the key taxa in the co-occurrence network.The bacterial taxa from the same module of the network had strong ecological connections,participated in C-cycles,and shared common trophic properties.PICRUSt analysis showed that bacteria were involved potentially in various essential processes;and the abundance of predicted xenobiotic biodegradation genes showed a decreasing trend in water samples from the inlet to the outlet of the reservoir.These results improve our current knowledge of the spatial distribution of bacteria in water and sediment in ecological purification reservoirs.     

Effects of elevated solar UV-B radiation from ozone depletion on terrestrial ecosystems

In the last three decades much research has been carried out to investigate the biological effects of a thinning stratospheric ozone layer accompanied by an enhanced level of solar ultraviolet-B radiation at the Earth‘s surface.Enhanced UV-B radiation affects ecosystems in many ways directly and indirectly. The responses can be biochemical, physiological, morphological or anatomical, and the direction of the response can vary between different species, communities and ecosystems. In this paper we firstly introduce general concepts, and methods for measuring the ecological effects of UV-B radiaticn. Secondly, we provide an overview interpretation of the effects of enhanced UV-B on terrestrial ecosystems from recent studies.These studies include effects of UV-B on growth and reproduction, composition of communities,competitive balance, decomposition of litter, and interactions with other factors etc. Finally, we recommend future research directions to identify the effects of elevated UV-B radiation on ecosystems in China.     

南阳伏牛山自然风景区的旅游价值

伏牛山是河南省的著名山脉 ,是我国亚热带向北暖温带的过渡带 ,是长江、黄河、淮河三大水系的分水岭 ,是华北地台和扬子地台的结合部。这里动、植物资源丰富 ,自然景观优美迷人 ,开发以旅游观光 ,生态示范 ,休闲度假、科普探险为一体的生态旅游区非常理想 ,是河南省近期重点开发的两条旅游线之一。文章从地质资源等方面详细介绍了伏牛山的概况 ,全面分析了伏牛山特殊的旅游价值和开发优势 ,提出了伏牛山生态旅游开发的基本思路 ,为伏牛山的系列开发提供了较好的科学依据。