The prevalence and species richness of spiders associated with marine strandlines on different shore types around Banks Peninsula,New Zealand

ABSTRACT

Marine strandlines provide habitat for a variety of littoral and terrestrial invertebrates, including arachnids. In this study we recorded spiders in strandlines at 35 sites on Banks Peninsula, New Zealand. On average, only 1.5 named species were recorded per thirty-minute hand search, and many sample visits (30%) recorded no spiders. Species accumulation curves suggested further species could be recorded with further sampling, but these may be tourist species rather than strandline residents. Thirty-eight species were recorded in total, with the introduced theridiid Steatoda capensis being the most common (30 records) and widespread (17 locations). The New Zealand endemic species Otagoa nova (25 records) (Toxopidae), Anoteropsis litoralis (15) and Anoteropsis hilaris (15) (Lycosidae), and the introduced Tenuiphantes tenuis (24) (Linyphiidae), were also common. Spiders were more frequent in strandlines on boulder beaches compared with shingle beaches, although there was no statistical differences in the numbers of species recorded on the different beach types.     

湖北省兴林灭螺专家系统的研制和开发

利用提取式数据库管理技术建立了兴林灭螺复合生态模式基本因子数据库,实现对各种数据的快速查询、筛选、排序等操作,在建立多种数学模型进行数据处理的基础上,用Ｖｉｓｕａｌ Ｂａｓｉｃ 函数实现了动态数据链接,通过ＤＤＥ 技术实现了数据、信息和图象的转换．运用面向对象的知识表示法建立了系统的知识类层次,完善了相应的推理机制．通过对拟开发滩地相关因子的量化处理,完成滩地的立地类型划分和立地质量评价, 推荐优化生态模式、技术措施等,提出经济、生态、社会三方面的效益分析．并设计了多种满足ＧＵＩ 标准的交互式人机界面．     

The relationship between heritage,recreational quality and geomorphological vulnerability in the coastal zone: A case study of beach systems in the Canary Islands

The relationships between geomorphological vulnerability, recreational quality and heritage at beaches in the Canary Islands (Spain) are studied using three sets of indicators. Processes and their interactions are analysed at urban, semi-urban and natural beaches. Natural, cultural and landscape heritage acts as an attractor of recreational activity, which has intensified significantly on Canarian beaches in recent decades. Overcrowding has negatively impacted conservation of the natural and cultural heritage of the beaches, and has increased human pressure, leading to an increase in geomorphological susceptibility. The resulting reduction in geomorphological resilience has had a negative impact on beach facilities. Despite this common pattern, the relationships between these processes have particularities associated with the different types of beach (urban, semi-urban and natural). In order to establish new priorities in coastal public policy, these beach diagnoses and indices should be discussed and debated by the different actors involved in beach management.     

Isostatic rebound in the northwestern part of the Lake Agassiz basin: Isobase changes and overflow

Based on new GPS elevation data on the Upper and Lower Campbell strandlines in the northwestern part of the glacial Lake Agassiz basin, the trend of isobases representing differential glacio-isostatic rebound in that region is shown to bend and assume a nearly west-east orientation. This differs from the northwest-southeast orientation to the southeast of the study area, which others had projected into the northwestern corner of the Lake Agassiz basin; this means that there was more isostatic depression than previously thought north of ∼ 53°N. The difference in slopes on reconstructed water planes of the Upper and Lower Campbell beaches is less with these isobases, which better reflects the short period of time between their formation. It is likely that the change in orientation of isobases reflects the presence of a thick Keewatin ice center to the north. Our revised west-east isobase reconstruction indicates that when the lake was at the Campbell beach levels, ∼ 9900-9400 ¹⁴C B.P., Lake Agassiz overflowed across the paleo-divide at Wycherley Lake, Saskatchewan, which controlled flow through the Northwestern Outlet of Lake Agassiz during part of its history; overflow would not have occurred through the Wycherley Lake channels at this time using the old isobase projections.