滨海沙滩珊瑚菜种群的空间格局及其对岸垄的响应

珊瑚菜(Glehnia littoralis)是国家Ⅱ级重点保护植物,天然分布在中国滨海沙滩潮上带。为认识珊瑚菜种群的更新机制及其对岸垄阻隔的响应,以青岛市胶南沙滩为例,调研沙垄前后珊瑚菜野生种群的分布和结构特征。结果表明:在分布格局上,垄前珊瑚菜在2.5 m的空间范围内呈聚集分布,成株与幼苗没有负关联性,而在更小尺度上表现明显的正关联性;垄后珊瑚菜表现出聚集范围变窄和聚集强度减弱的趋势,成株与幼苗的正关联性减弱,甚至有明显的负关联性;在种群结构上,垄前珊瑚菜的相对密度较高,幼苗较多,结实量较大,更新正常;相反,垄后珊瑚菜的密度、幼苗数量、结实量均降低或减少,更新过程明显受阻。据此推断,岸垄可能通过抑制潮水对种子的传播而阻碍珊瑚菜的天然更新。     

High Metabolic Rates in Beach Cast Communities

Metabolic hotspots at land–water interfaces are important in supporting biogeochemical processes. Here we confirm the generality of land–aquatic interfaces as biogeochemical hot spots by extending this concept to marine beach cast materials. In situ atmospheric pCO_2, from a respiration chamber (10 cm in diameter and 20 cm high) inserted into wrack deposits, was determined using a high-precision (±1 ppm) non-dispersive infrared gas analyzer (EGM-4, PP-systems) at 1 minute recording intervals. The wrack deposits supported high metabolic activities, with CO₂ fluxes averaging (±SE) 6.62 ± 0.88 μmol C m⁻² s⁻¹, compared to median value of 0.98 μmol C m⁻² s⁻¹ (mean 2.21 ± 1.25 μmol C m⁻² s⁻¹) for bare sand adjacent to deposits. Wrack metabolic rates ranged 40-fold across beaches, from a minimum of 0.57 ± 0.22 μmol C m⁻² s⁻¹ to a maximum of 20.8 ± 5.04 μmol C m⁻² s⁻¹, both derived from beaches with deposits dominated by Sargassum. Rates tended to increase significantly (F test, P < 0.05) from the shoreline to reach maximum rates at about 10 m from the shoreline, declining sharply further from the shoreline, and increased with increasing thickness of the deposits (maximum about 10 cm deep), declining for thicker deposits. Wrack differing in composition had similar metabolic rates, although deposits consisting of a mixture of seagrass and algae tended to show somewhat higher rates. Our results show a meter square of wrack deposit supports a metabolic rate equivalent to that supported by 3 m² of living seagrass or macroalgal habitat. In wrack, the marine environment provides organic material and moisture and the land environment provides oxygen to render wrack ecosystems an efficient metabolic reactor. Intense wrack metabolism should also be conducive to organismal growth by supporting the development of a cryptic, but diverse wrack-based food web.     

Enumeration and speciation of enterococci found in marine and intertidal sediments and coastal water in southern California

AIMS: To determine the levels and species distribution of enterococci in intertidal and marine sediments and coastal waters at two beaches frequently in violation of bacterial water standards. METHODS AND RESULTS: Faecal indicator bacteria were extracted from sediment and enumerated using membrane filtration. High levels of enterococci were detected in intertidal sediments in a seasonal river and near a storm drain outlet. Low levels were found in marine sediments at 10 m depths and in surf zone sand. Bacterial isolates presumptively identified as Enterococcus on mEI media were speciated. The predominant species found in both water and sediment included Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Enterococcus casseliflavus and Enterococcus mundtii. A number of isolates (11-26%) from regulatory water samples presumptively identified as enterococci on mEI media were subsequently identified as species other than Enterococcus. At both study sites, the distribution of species present in water was comparable with those in sediments and the distribution of species was similar in water samples passing and exceeding bacterial indicator standards. CONCLUSIONS: High levels of Enterococcus in intertidal sediments indicate retention and possible regrowth in this environment. SIGNIFICANCE AND IMPACT OF THE STUDY: Resuspension of enterococci that are persistent in sediments may cause beach water quality failures and calls into question the specificity of this indicator for determining recent faecal contamination.     

基于CVM的海涂湿地生态服务价值的模糊评估模型

正确评估海涂湿地生态服务价值有助于加强人们保护海涂湿地的意识,为海涂湿地围垦生态补偿标准的制定提供依据。视价格"便宜"、"适中"和"昂贵"为模糊集,基于CVM法区间型数据建立了传统模糊统计模型、赋权模糊统计模型和三相划分模型,并以此评价了杭州湾国家湿地公园单位面积年生态系统服务价值。结果显示:3种方法得到的单价分别为10.28、10.38、9.76元m~(-2)a~(-1),三者一致程度较高,与国内沿海湿地价值比较接近。分析了"生态价值"概念客观上的"模糊性"引致模糊数学模型的合理性;采用"橄榄球"式赋权建立赋权模糊统计模型以克服传统模糊统计模型中对区间数据均匀赋权的不合理性,结果在隶属度函数的光滑性和拟合度上好于后者;第三,三相划分模型拟合出3个模糊集的隶属度函数,可以比较相同价格在不同模糊集中隶属度差异。建立的模型对于基于CVM法的生态资源价值评估具有借鉴意义。     

江苏海涂苇田芦毒蛾的生态控制

１９９２￣１９９５年江苏海涂苇田的调查表明,芦毒蛾种群数量消长的主要影响因子是糙叶苔、苇田干湿度以及芦毒蛾黑卵蜂和寄生菌等。提出了以生态控制为基础的综合防治措施,包括因地制宜地赶火烧滩;利用苇田内高湿或浅灌消灭越冬幼虫;清除糙叶苔;保护和利用芦毒蛾黑犷睡其他防治措施的协调运用等。     

Effect of light intensity on the locomotor activity rhythm of Talitrus saltator (Montagu 1808) from Korba Beach

In this work, we investigate the locomotor behaviour of Talitrus saltator (Montagu 1808) for a population collected from the supralittoral zone of Korba beach. The locomotor activity rhythm was recorded for adult individuals during 10 summer days under continuous light with four different luminous intensities: 5 lux (N = 30), 35 lux (N = 30), 75 lux (N = 30) and 140 lux (N = 15). By the end of the experiments, 100% of the considered individuals were found alive under light intensities of 35 and 140 lux, whereas only 86 and 90% were found alive under light intensity of 5 and 75 lux, respectively. Furthermore, whatever the imposed luminous intensity is, actograms showed a clear drift to the right lengthening day after day the circadian period. Moreover, we found that by raising the light intensity, the drift becomes increasingly important. Actograms as well as activity curves, results showed that the locomotor activity profiles are mainly unimodal and their percentage increases when increasing the light intensity. Furthermore, periodogram analysis highlighted the presence of ultradian and circadian components where the longest periods were observed with the highest luminous intensity. In addition, the locomotor activity rhythm was statistically more defined and individuals of Talitrus saltator were significantly more active under the lowest luminous intensity.     

崇明东滩湿地自然植被演替过程中储碳及固碳功能变化

采用实地调查与实验室测定相结合的方法,研究了崇明东滩湿地植被演替过程中储碳、固碳功能的变化.结果表明：不同演替阶段的湿地植被的现存碳储量及其分配格局特征存在较大差异.先锋物种海三棱藨草的现存碳储量仅占芦苇现存碳储量的13%;地下根茎为芦苇现存碳储量的主要场所,而地上部分是海三棱藨草碳储量的主要场所.处于潮滩湿地演替中后期的芦苇群落比处在生态演替早期的海三棱藨草群落具有更强的固碳能力,芦苇群落和海三棱藨草群落的年固碳能力分别为(1.63±0.39) kg·m^-2和(0.63±0.28) kg·m^-2,说明随着海三棱藨草群落向芦苇群落演替,其固碳能力不断增强.     

Feeding ecology of juvenile flatfishes of the surf zone of a sandy beach

Prey items of 0- and 1-group plaice Pleuronectes platessa , sole Solea solea , brill Scophthalmus rhombus , turbot S. maximus and dab Limanda limanda of the surf zone of a Belgian sandy beach, included hyperbenthic (e.g. mysids), endobenthic (e.g. polychaetes) and epibenthic (e.g. shrimps) species. Little dietary overlap was observed. If diet overlap did occur, it mainly involved prey species that are dominant in the surf zone of Belgian beaches, such as shrimps and mysids. These results suggest an opportunistic utilization by flatfish of the available food resources in surf zone ecosystems. Also, two strategically different feeding habits could be distinguished between the five flatfish species. Turbot and brill mainly fed on large, highly mobile prey (e.g. fish, mysids) and had a rather narrow prey spectrum, whereas plaice, dab and sole ate more benthic prey (e.g. polychaetes) and had a broader prey spectrum.     

长江干流季节性水淹滩地杨树生长规律研究

研究了长江中下游干流滩地抑螺防病林的主要树种杨树的生长规律,建立了杨树的生 长动态数学模型．经过进一步的生长动态模型分析,研究结果表明：滩地高程是影响杨树胸径、 树高和材积生长量的关键因子．滩地淹水时间超过６０天的地方,杨树生长受到明显的影响．     

Early life history of a catadromous sculpin in western Japan

To clarify the early life history of Cottus kazika (Cottidae), the ontogeny, osteology, distribution, migration and food habit were examined based on larvae and juveniles collected from coasts and estuaries in western Japan. The sequence of fin completion was pectoral (P1)-dorsal soft-ray part (D2)-anal (A)-dorsal spine part (D1)-pelvic (P2). However, that of calcification was P1-P2-D1-D2-A. Larvae and juveniles of C. kazika are distinguished from those of coastal sculpins of Japan by large preopercle spines, conspicuous parietal spines, the large and densely pigmented pectoral fin and the relatively deep body. C. kazika and Myoxocephalus polyacanthocephalus plus Enophrys bison share these four ontogenetic characters. From the relationship between the growth ring count on the sagittae and total length, the size of embryos at hatching is estimated at 5.2 mm. Larvae are estimated to reach 7 mm in 10 days, 9 mm in 20 days and 11 mm in 30 days after hatching. Hatching dates for larvae collected in the Shimanto estuary in 1987 peaked during the period around the new moon in January. Many free embryos ranging from 4.3 to 5.9 mm were collected using an aqualamp at a rocky shore outside the Yura River mouth, at high salinity (> 33 ppt), but none were collected in the estuary. From beach samples, seasonal changes in body size varied from year to year, and no consistent growth pattern was found, although juveniles were generally larger in late March and April than in January and February. Very few larvae were collected along shorelines where there were no adjacent rivers. Food habit of larvae and juveniles changed with growth. Polychaete larvae, cladocerans and copepods were found in preflexion larvae less than 6 mm. Gammarids were one of the important food items for larvae over 6 mm. Juveniles over 12 mm almost exclusively fed on gammarids. In the Shimanto estuary, larvae and juveniles stayed near the river mouth in January and February, within a stagnant layer where temperature and salinity remained about 12 °C and 20 ppt, respectively. Juveniles tended to move in March when the stagnant layer disappeared in the estuary.