城市发展推动下的济南市景观格局变动研究 ——基于2007—2017年景观格局指数的分析

采用2007年的Landsate5TM、2013年和2017年的Landsate8OIL遥感影像,选取分维度、蔓延度、香农多样性指数、香农均匀度指数等指标,从类型水平和景观水平两个方面,对济南市主城区10年间的景观格局进行分析,结果表明:城市整体的斑块丰富度增加,生态系统趋于多样化;未利用地面积逐渐减少,林地与耕地面积显著增加;耕地质心逐渐“北跨”,这与10年间济南市整体的政策定位与城市发展脉络相契合。提出大力推动农村社区规划,严格控制占用林地、狠抓植被恢复,做好城市建设用地规划、预留发展空间等土地利用的建议。     

Using otolith microchemistry to reconstruct habitat use of American eels Anguilla rostrata in the St. Lawrence River–Lake Ontario system

Catadromy among freshwater eels is increasingly recognised as being facultative, with some individuals carrying out growth exclusively in brackish or coastal marine waters, or switching between brackish or marine waters and freshwater habitats. In an attempt to reconstruct habitat use of yellow‐stage American eels in a large river‐lake ecosystem, trace element line scans were obtained, using LA‐ICP‐MS, from the otoliths of 110 eels sampled at various locations throughout the St. Lawrence River–Lake Ontario (SLRLO) system. Elemental profiles for strontium (Sr), barium (Ba), manganese (Mn) and magnesium (Mg) enabled us to distinguish three chemical signatures that appear to represent three distinct habitats within the SLRLO. Of these, one was shown to likely correspond to the brackish estuary (high strontium values). The other two signatures, characterised by low strontium but variable concentrations of barium and manganese, may correspond to habitats within the main‐stem St. Lawrence River and one or more of its tributaries. Most (78%) of the switches among habitats occurred within the first four years after recruitment suggesting an increasing likelihood for eels to maintain residence in one habitat as they grow older. This suggests that tributaries may provide important habitats for American eels during the first several years after recruiting to the SLRLO. In addition, our results suggest that a small proportion American eels in the SLRLO can undertake movements on the order of at least 200 km during the early growth stage. This information has important implications for the management and conservation of this species in the system.     

Variability in movement dynamics of topminnow (Fundulus notatus and F. olivaceus) populations

Abstract – Movement and dispersal patterns are key biological processes across a range of organisational levels. The Fundulus notatus species complex includes several species with similar ecological niches that exhibit broadly overlapping ranges. We conducted a mark–recapture study on two of the most widely distributed members of this species complex to improve our understanding of their movement and habitat use. A population of F. notatus was studied between June and August of 2008 and 2009 in Cahokia Creek, a small tributary of the Mississippi River in Illinois, along with a parallel study of Fundulus olivaceus between May and July of 2009 in Big Creek, a tributary of the Pascagoula River in Mississippi. Fish were recaptured approximately weekly, and habitat variables were measured. Estimated daily movement rates varied significantly both between locations and between years. Fundulus olivaceus in Big Creek moved <1 m per day, while F. notatus in Cahokia Creek in 2009 moved nearly 23 m per day. The distribution of movements was strongly leptokurtic in all three data sets. Differences in movement rates were attributed to significant differences in population size and habitat characteristics. Our data did not support the hypothesis that populations consist of distinct mobile and resident components. Instead, individual fish went through periods of little or no movement followed by extensive movement (consistent with the home range shift model of fish movement). We discuss the implications these results have for contact zone dynamics between these two species.     

导流墩在电厂循环水流道中的应用研究

针对某1000 MW电厂循环水流道所采取的曲线型平面布置形式,通过模型试验分析了曲线引水段弯道环流运动所带来的不利影响.为遏制环流运动,调整水流流速分布,结合流道进口前沿冷却塔人字柱支墩的结构布置特点与相对位置,将其改造为流线型导流墩,用以控导引水段水流运动.模型试验表明,导流墩有效梳理了弯道段水流流向,均化了流速分布.该项措施为实现流道各流段衔接顺畅,泵室吸水池来流均衡提供了保证,同时对于类似的流道工程设计具有参考意义.     

南狮运动的起源、形成与发展研究

舞狮是一项历史悠久、独具民族特色的民间传统体育运动项目。运用文献资料、口述史、专家访谈等研究方法，对南狮运动的起源、形成与发展历程进行深入研究，对构成南狮运动文化的基本因素进行论证和阐述。研究表明：南狮运动的最早起源于南北朝时期，与当时的社会环境、生活习俗有着密切的联系，有着明显的地域特征和民族文化特性。南狮运动具有竞技、健身、娱乐等多种价值，是我国重要的体育文化遗产。     

山丘区河流滩地边缘内凹形态对溶质运移及水质恶化风险的影响

滩地是河流的重要组成部分,具有调蓄洪水、净化水质、供生物栖息等功能。以浙江龙游县灵山港为典型山丘区河流,在现场勘测的基础上,提出了弯曲度指数(I-e)以表征滩地边缘内凹形态。基于I-e,滩地内凹形态可划分为低弯(I-e<2)、中弯(2≤I-e<4)和高弯(I-e≥4)3个等级。根据对灵山港下游18个滩地4次现场监测数据,并应用Mike 21构建该河段的二维水动力-水质耦合模型,定量分析了近滩区溶质运移过程。现场监测与数值模拟均表明随着I-e升高,河流水质风险随之呈极显著升高(P<0.01)趋势。模拟结果进一步表明,适当降低高弯内凹形态可有效降低河流水质风险;而根据维持生境多样性的需求,不宜将内凹形态降至低弯。所获取的不同边缘形态下的溶质时空分布可为滩地保护及修复提供重要参考。     

The complementary role of lentic and lotic habitats for Arctic grayling in a complex stream‐lake network in Arctic Alaska

Lakes can be important to stream dwelling fishes, yet how individuals exploit habitat heterogeneity across complex stream‐lake networks is poorly understood. Furthermore, despite growing awareness that intermittent streams are widely used by fish, studies documenting the use of seasonally accessible lakes remain scarce. We studied Arctic grayling (Thymallus arcticus) in a small seasonally flowing (June–October) stream‐lake network in Alaska using PIT telemetry. Overall, 70% of fish visited two lakes, 8% used a single lake, and 22% used only stream reaches. We identified five distinct behavioural patterns that differed in dominant macrohabitat used (deep lake, shallow lake or stream reaches), entry day into the network and mobility. Some juvenile fish spent the entire summer in a shallow seasonally frozen lake (average 71 days), whereas others demonstrated prospecting behaviour and only entered the stream channel briefly in September. Another group included adult and juvenile fish that were highly mobile, moving up to 27 km while in the 3‐km stream‐lake network, and used stream reaches extensively (average 59 days). Lentic and lotic habitats served differing roles for individuals, some fish occupied stream reaches as summer foraging habitat, and other individuals used them as migration corridors to access lakes. Our study emphasises the importance of considering stream‐lake connectivity in stream fish assessments, even to shallow seasonally frozen habitats not widely recognised as important. Furthermore, we demonstrate that individuals may use temporary aquatic habitats in complex and changing ways across ontogeny that are not captured by typical classifications of fish movement behaviour.     

Flow‐mediated movement of freshwater catfish,Tandanus bostocki,in a regulated semi‐urban river,to inform environmental water releases

Movement and migration of fish are critical for sustaining riverine fish populations. Water resource development alters natural flow regimes and can disconnect habitats and interfere with hydrological cues for fish movement. Environmental flow releases can counter these impacts, but to be effective they must be based on quantitative flow–biota relationships. We used radio‐telemetry to investigate the association between flow and movement of Tandanus bostocki, a plotosid fish endemic to south‐western Australia. Movement was assessed for 15 adult fish at three temporal scales: weekly, daily and bihourly to reveal seasonal patterns in movement, movement around individual flow pulses, and to describe changes in home range respectively. We used a predictive modelling approach to assess the importance of discharge and other covariates on the directional distance travelled or linear home range size. Our seasonal and flow pulse study revealed that T. bostocki undertook larger downstream movements during higher flows and smaller upstream movements during lower flows. Daily movements tended to be downstream on the ascending limb of flow pulses and upstream on the descending limb. Flow‐dependent movements at weekly or daily time scales were relatively modest (typically hundreds of metres) and were moderated by time of year and gender; however, fish underwent a synchronised 1‐km movement upstream during the known reproductive period in October. The home range study revealed that T. bostocki had larger home ranges (night‐time foraging) when baseflow was elevated. These results can assist the design of customised environmental flows in the study river and other flow‐regulated rivers.