亚热带岩质海岸不同类型植被的水土保持效益

通过设立径流小区和多元回归分析等方法, 对亚热带岩质海岸不同植被类型的水土保持效益进行了对比研究。结果表明: 由于林木处于幼龄阶段, 不同植被类型的地表径流量削减率较小, 平均比对照降低9-05 % ; 侵蚀模数比对照平均削减39-29 % 。不同植被类型下的土壤含水率比对照提高17-94 % ; 土壤含水率除了与植被类型有关外, 还与土壤物理特性有较密切的关系; 影响土壤含水率的土壤物理因子主要为土壤容重, 其次为非毛管孔隙度与总孔隙度之比和非毛管孔隙度。影响土壤含水率的主要气象因子为平均气温和降水量。土壤物理特性对地表径流量的影响大于对侵蚀模数的影响。表4 参12     

东海岛沙质海岸木麻黄无性系的生长比较

在东海岛沙质海岸防护林营造中,选用木麻黄8 个优良无性系和1 个本地实生苗进行造林对比试验。结果表明:造林后第3 年起8 个无性系的树高生长均快于实生苗,其中无性系“503”树高生长一直保持最快;随着时间的推移,无性系间树高生长差异有逐步缩小的趋势;到第5 年“503”树高生长与其他7 个无性系已无显著差异,只显著快于实生苗。4 年生前木麻黄各无性系间的胸径生长无显著差异,从第5 年起无性系“南三7”与实生苗的生长差异显著,此后,8 个无性系全部超过实生苗。     

黄海北部近岸鱼类的群落结构

1998年6月和9月通过对24个站位的底拖网调查,分析了黄海北部近岸水域鱼类的群落结构特征。结果表明：该水域鱼类的品质结构低质化,经济价值较低的中上层鱼类成为渔业资源的主要成分;区系组成以暖温性鱼类为主;鱼类群落结构较简单,其多样性和丰富度指数都很低,均匀度指数处中上水平。     

漳州滨海火山国家地质公园旅游开发的SWOT分析及其发展对策

漳州滨海火山地质公园是中国现有国家地质公园中规模最大、保存完好、景观最有特色的滨海火山国家地质公园。通过对其旅游开发进行SWOT分析,并借鉴国内旅游开发的成功案例,得出该国家地质公园的发展应抓住当前海西旅游发展的机遇,充分利用特有的滨海火山地质景观开发旅游产品,并通过促销宣传,以实现公园旅游的进一步发展。     

浙江沿海海洋水产动物的多氯联苯检测分析

对浙江沿海5个地区的贝类、虾类和鱼类等水产动物体内的多氯联苯进行GC-MS检测分析,研究多氯联苯各单体在不同生物体内的分布特征、影响因素和积累分布规律。结果表明：浙江沿海海域生物多氯联苯检出率为100%,ω(PCBs)为0.12～9.40μg/kg,低于国家标准限量。其中,贝类中ω(PCBs)为0.83 ~10.52 ng/g,平均值为4.20ng/g;虾类ω(PCBs)为0.43~2.18ng/g,平均值为1.27ng/g;鱼类中ω(PCBs)为0.50～2.63ng/g。平均值为1.61ng/g。总体看不同种类海洋生物PCBs含量贝类>鱼类>虾类。从地区分布来看三门地区海产品中PCBs含量最高,玉环、椒江次之,宁海最低。甲壳类样品的PCBs检出以六氯联苯(PCB138)为主,鱼类样品的PCBs检出以五氯联苯(PCB118)为主,表现出水生生物对高氯联苯富集量高于低氯联苯富集量的共同点。而在各类动物中PCBs检出量最高的样品,如缢蛏、僧帽牡蛎和菲律宾蛤仔,都表现出了对于四氯联苯（PCB52）的强富集能力。     

Mortalities caused by the crustacean isopod, Cirolana fluviatilis, in tropical, cage-cultured Asian seabass, Lates calcarifer: a case study from the southwest coast of India

Recurring mortalities inflicted by the cirolanid isopod Cirolana fluviatilis in the juveniles of the Asian seabass, Lates calcarifer , stocked in a cage farm in the Cochin backwaters, from November 2006 to May 2007, were investigated. Hatchery-reared fingerlings (size 8–12 cm) were cultured in floating cages and mortalities were observed after a rearing period of 1 month. The fish were found dead in the cages, with only the remnants of fish skeleton and all the flesh eaten away. Investigations revealed a very high abundance of isopods, identified as C. fluviatilis (Crustacea, Malacostraca, Isopoda and Ciroloanidae). During the first 2 months of stocking, 35% of the fingerlings died, and the cumulative mortality reached 45% in 6 months, considerably reducing the profits from the venture. Management measures for the control of the isopods are discussed. This is the first report on the isopod, C. fluviatilis , inflicting serious mortalities in a tropical cage-rearing system in the southwest coast of India.     

对青海湖北岸部分地区嵩草的调查研究

通过对青海湖北岸海拔3000－3500m部分地区不同类型嵩草属植物的调查分析表明：在沼泽草甸上西藏嵩草（Kobresia tibetica）、矮生嵩草（K.humilis）及其它莎草生长良好，但由于沼泽草甸潮湿，绵羊对这些牧草利用差，牛、马利用较好；山地干草原草场不适宜嵩草属植物生长，仅分散着少量大花嵩草（K.macrantha），经济价值不大；在大片的撂荒地中几乎完全没有嵩草属牧草；在山地草原化草甸草场上，以矮生嵩草、短轴嵩草（K.prattii）、线叶嵩草（K.capillifolia）及禾本科牧草为优势种，豆科牧草相应增加、杂类草相应减少，为最佳放牧场，各类牲畜均能很好地采食；在高寒草甸草场上，高山嵩草（K.pygmaea）为绝对的优势种，因植株矮小，牛、马利用差，绵、山羊则能很好地利用。盲目开垦、过度放牧和不合时令的放牧是造成草场退化的主要原因。     

Impacts of rainstorms on soil erosion and organic matter for different cover crop systems in the western coast agricultural region of Syria

More and more cultivated coastal territories of Syria are being affected by increasing land degradation processes, specifically, by soil erosion due to non‐sustainable soil management. The use of cover crops can be considered an ideal solution to reduce the negative impacts of extreme rainfall events on soil erosion. However, there is no enough information about the main cultivated areas of Syria due to the current conflicts and the very few types of research conducted there. Therefore, the main aim of this research was to assess soil erosion (soil loss and sediment concentration) and hydrological response (run‐off and infiltration) considering the impact of different types of cropping systems on soil organic matter. To achieve this goal, using erosion plots, five grouped natural rainfall events and soil samples were collected, and infiltration measurements were performed between November 2012 and April 2013 (rainy season) on three different cropping systems (wheat, vetch, bean and control) with different sloping gradients (8% and 20%) in Tartous governorate (W Syria). Our results showed a cumulative rainfall amount from 68.8 to 201 mm during the study period. The highest sediment yield was generated in the control and wheat plots, registering 0.468 and 0.368 kg m^?2, respectively, with an inclination of 8%. For an inclination of 20%, the control and wheat plots registered 1.145 and 0.967 kg m^?2, respectively. In comparison with the control plots, there was a decrease in the total eroded organic matter, which ranged from 0.0579 (control) to 0.0289 (bean) kg m^?2 year^?1 in the plots with 20% inclination, and from 0.0233 (control) to 0.0069 (bean) kg m^?2 year^?1 with 8% inclination. To sum up, bean and vetch play an effective role to mitigate soil erosion, delay run‐off and reduce sediment yield. The output of this research provides first insights into the impact of different land uses on soil loss. Also, it could help rural inhabitants and farmers to correctly manage their soils against soil erosion processes.     

Deep-water rice production as influenced by time and depth of flooding on the east coast of India

The saucer-shaped landform, high rainfall due to the south-west monsoon (June–September) and poor drainage conditions make certain parts of the east coast of India susceptible to waterlogging during the rainy season. There is no alternative other than to grow rice in the coastal lowlands, where surface water accumulation of 0.5–2.0 m occurs during the rainy season. In this study, the physical environments of a representative deep-water ecology were characterized and the performance of improved deep-water rice (DWR) varieties (Hangseswari, Saraswati, Ambika, Sabita) was compared with that of local varieties (Bankei, Dhalakartik) at three water depths (shallow flooded [0.6–0.8 m], medium flooded [0.8–1.2 m] and deep flooded [>1.2 m]). The rainfall–flooding depth relationship was also studied and the probability of successful crop production in relation to the time and depth of waterlogging was investigated, based on historical (34 years) flood data from the region. Among the varieties studied, ‘Hangseswari’ was found to have superior physiological traits for growth, development and production of grain yield and hence may be considered for inclusion in further DWR breeding programs. With the introduction of improved DWR varieties, productivity during the rainy season was enhanced and farmers received good yield (2.05–2.95 t ha^?1) and net return (4500 Rs ha^?1).     

Pelagic eggs of marine fishes from Park Rynie,KwaZulu-Natal,South Africa: seasonal spawning patterns of the three most common species

For the period 1987 to 1998, pelagic eggs of marine fishes were collected from shelf waters at Park Rynie on the KwaZulu-Natal south coast. The three most numerous eggs collected were those of the mackerel Scomber japonicus,the sardine Sardinops sagax and the East coast roundherring Etrumeus teres. Together they comprised 67 % of all eggs collected. At times single-species egg densities were high, the highest accurately recorded was 850 eggs/cubic metre for S. sagax. All three species were predominantly winter to spring spawners. Theseasonal pattern of sardine eggs at Park Rynie suggests that after entering KwaZulu-Natal waters in June, sardines remain until November or December of each year before returning south to eastern Cape waters. Spawning in the East coast roundherring began in June, peaked in October to November, and tailed off in January. The mackerel showed a similar pattern of spawning, beginning in June and ending in December.