The Change in Outgoing Long-wave Radiation before the Ludian MS6.5 Earthquake Based on Tidal Force Niche Cycles

The cycle process of the tidal force niche for the Ludian M_S6.5 earthquake occurring in Ludian County, Yunnan Province, China on August 3, 2014 was calculated. The earthquake occurred near the middle point phase. It indicates that the type of seismogenic fault that the tide force acted on belongs to the thrust fault. According to the tidal niche cycle,the abnormal OLR( Outgoing Long-wave Radiation) change was analyzed based on NOAA satellite data around the whole land area of China before and after the earthquake.The result shows that the OLR changed evidently with tide force change. Temporally,the change went through the evolution process of initial OLR rise → strengthening → abnormal peaking → attenuation → returning to normal; and spatially,the abnormal area wound its way along the Zhaotong-Ludian fault and went through a scattered → conversion →scattered process. This process is similar to the change process of rock breaking under stress loading. The results indicate that the tidal force of a celestial body could trigger an earthquake when the tectonic stress reaches its critical breaking point and the OLR anomaly is proportional to the seismic tectonic stress change. It is of great use to combine OLR and tidal force in earthquake precursory observation.     

Seasonal and ontogenetic changes in the diet of blenny Hypleurochilus fissicornis: An estuarine mariculture as a model of the reef environment

The Blenniidae family is characterised by small cryptic fish. Due to the small size of these specimens, the sampling is very difficult and information about the ecological role of these fishes is vague. However, mariculture adds reef encrusting organisms that attract blennies, which makes sampling easier. Furthermore, recognising species feeding is critical to understand biological communities. In this study, we evaluated the diet of blenny Hypleurochilus fissicornis in a mariculture, to clarify its influence on the benthic fauna and its interactions with the reef environment. We evaluated the seasonal variation (four seasons chosen by the abiotic variables) and the ontogenic changes (three classes defined by L₅₀ of the species: juvenile, transition and adult) in the diet. Hydrozoans were the main prey, but H. fissicornis fed on a variety of other benthic organisms, exhibiting opportunistic habits. The diet of H. fissicornis was complemented by Amphipods in autumn, Ostracods in winter, and bivalves in summer. Juveniles fed more on Ostracods than the other classes, while the transition class fed mainly on Hydrozoans and a variety of rare items, and adults consumed almost exclusively Hydrozoans and some Cirripedia. Therefore, we conclude that H. fissicornis is an opportunistic feeder and may influence benthic organisms. The establishment of fouling organisms on the mariculture structures allows the use of this area by the blenny, since they promote its feeding base.     

河西内陆河流域水生态安全评价研究

水安全评价相关研究已有较多成果,但绝大多数采用P-S-R(压力-状态-响应)及其扩展模型,且评价指标体系的优化校准几乎从未提及.本文将W-SENCE(与水有关的社会-经济-自然复合生态系统)模型引入水生态安全评价领域,从水生态安全的自然属性和社会经济属性方面构建水生态安全评价指标体系,结合模糊系统分析及改进生态位理论对...     

区域性温血金枪鱼的生理学特征研究进展

金枪鱼体型庞大,游泳速度快,是海洋中的顶级捕食者,且具有很高的营养价值和经济价值,对全球渔业具有重要意义。由于具备独特的温血能力、发达的视觉系统、较高的基础代谢率,金枪鱼拥有特殊的生活习性和热生态位。为此,本文从温血产热机制、逆流热交换血管网、心脏耐寒性能、视觉系统和生长模式等5个方面对金枪鱼相关的生理学研究现状进行了综述。在此基础上,本文讨论了金枪鱼生理特征与环境适应性、热生态位和营养生态位之间的密切联系。最后,本文提出了金枪鱼生物信息学研究的建议和需要进一步考虑的问题。     

Ecological niches and areas of overlap of the squat lobster ‘munida’ (Pleuroncodes monodon) and anchoveta (Engraulis ringens) off Peru

The world’s largest mono-specific fishery, the Peruvian anchovy or anchoveta (Engraulis ringens) fishery, has been the subject of many studies since the 1960s. Details of its relationship with other species have mainly focused on alternations with sardine, Sardinops sagax, and little effort has so far been paid to interactions with other species sharing the same ecosystem. This is the case for Pleuroncodes monodon, the crustacean squat lobster or ’munida’, which has become highly abundant along the Peruvian coast since the mid-1990s. Munida is now an important prey for seabirds, mammals and coastal predatory fish. Knowledge of patterns of distribution and ecological niche of munida is scarce however off Peru. Here we describe and compare spatial patterns of distribution of anchoveta and munida and their ecological niches based on data from 26 acoustic surveys performed along the Peruvian coast between 1998 and 2006. The results indicate that munida and anchoveta share ecological niches but that munida is restricted to the coldest part of the productive cold coastal waters whereas anchoveta do not present any temperature preference over a large range (14–23 °C). The recent increase in munida abundance off Peru is concomitant with colder conditions; with their onset munida extended its range from central Chile northwards. Off Peru the very shallow oxycline keeps munida from its usual bottom habitat and has forced it to adopt pelagic behaviour.     

海洋动物营养生态位研究方法及其应用

食物资源对海洋动物的生存和繁衍至关重要。海洋动物的营养生态位描述了其在海洋生态系统中的生态地位及功能, 对分析种间关系和资源分配模式、了解群落结构与功能具有重要的指示作用。本文在整理近30年来国内外相关研究的基础上, 系统归纳了当前海洋动物营养生态位研究的主要方法(胃含物分析、整体组织稳定同位素分析、脂肪酸组成分析和特定化合物稳定同位素分析)及其应用领域, 着重归纳总结了量化营养生态位宽度和重叠的生态模型, 并分析了各营养生态位评估方法的优势和局限性。同时在此基础上, 对今后研究方向提出了展望, 以期为我国海洋动物摄食生态学相关研究工作提供参考。     

基于均分法的小生境遗传算法

为了避免遗传算法种群中个体过早陷入局部最小,在以往随机初始种群的基础上提出一种均分法,使得初始种群随机平均地分为若干个子种群,形成小生境,这样既维持了种群的多样性,也使得种群中的个体不会过早出现早熟现象,更提高了算法的收敛速度.同时采用了自适应技术控制交叉和变异的概率,使得算法能更快速地找到最优解.仿真结果表明,与传统的遗传算法优化RBF网络相比较,新算法的迭代次数更少,精度更高,大大提高了收敛速度.     

南流江河口红树林潮沟主要鱼类时空生态位

基于2019年7月(夏)、2019年10月(秋)、2020年1月(冬)、2020年5月(春)的季节性鱼类采样数据,运用相对重要性指数(IRI)、Shannon指数和Pianka指数对南流江河口红树林潮沟主要鱼类的时空生态位宽度和重叠进行分析,结合冗余分析探讨主要鱼类间的生态位分化。结果表明：共采集到鱼类17 680尾,隶属12目23科37属45种,其中主要鱼类(IRI>100) 10种。在主要鱼类中,时间生态位宽度值变化范围为0.46～1.78,其中嵴塘鳢最大,爪哇拟虾虎鱼最小;空间生态位宽度值变化范围为0.81～2.05,其中斑尾刺虾虎鱼最大,爪哇拟虾虎鱼最小。时空生态位宽度值达到2以上(广生态位种)的种类有6种,分别是鲻、齐氏罗非鱼、中华乌塘鳢、斑尾刺虾虎鱼、嵴塘鳢和杂食豆齿鳗。鲻与爪哇拟虾虎鱼的时间生态位重叠值最高(0.928),尾纹双边鱼与食蚊鱼的空间生态位重叠值最高(0.979),齐氏罗非鱼与斑尾刺虾虎鱼的时空生态位重叠值最高(0.822)。南流江河口红树林潮沟主要鱼类时空二维生态位有6.7%的种对显著重叠(Q_ik>0.6),表明物种时空分布...     

Recognition and palaeoclimatic implications of late Quaternary niche glaciation in eastern Lesotho

Geomorphic evidence of former glaciation in the high Drakensberg of southern Africa has proven controversial, with conflicting glacial and non‐glacial interpretations suggested for many landforms. This paper presents new geomorphological, sedimentological and micromorphological data, and glacier mass‐balance modelling for a site in the Leqooa Valley, eastern Lesotho, preserving what are considered to be moraines of a former niche glacier that existed during the Last Glacial Maximum (LGM). The geomorphology and macro‐sedimentology of the deposits display characteristics of both active and passive transport by glacial processes. However, micromorphological analyses indicate a more complex history of glacial deposition and subsequent reworking by mass movement processes. The application of a glacier reconstruction technique to determine whether this site could have supported a glacier indicates a reconstructed glacier equilibrium line altitude (ELA) of 3136 m a.s.l. and palaeoglacier mass balance characteristics comparable with modern analogues, reflecting viable, if marginal glaciation. Radiocarbon dates obtained from organic sediment within the moraines indicate that these are of LGM age. The reconstructed palaeoclimatic conditions during the LGM suggest that snow accumulation in the Drakensberg was significantly higher than considered by other studies, and has substantial relevance for tuning regional climate models for southern Africa during the last glacial cycle. Copyright © 2009 John Wiley & Sons, Ltd.