岛屿地形下的核电厂护岸防洪设计研究

对国内第一个岛屿地形下核电厂的护岸防洪设计进行了研究,提出直立式护岸结构方案以满足核电厂防洪和避让毗邻海岛的要求。在波浪数值模拟计算结果基础上,开展了波浪整体物理模型试验、波浪局部整体物理模型试验和波浪断面物理模型试验,对护岸的越浪量和结构稳定性进行了优化验证。研究结果表明,岛屿地形下,波浪破碎和波能集中导致护岸堤身坡脚处波高增大,须加高挡浪墙和优化挡浪墙结构型式;在相同的越浪量标准下,采用直立堤结构相对斜坡堤结构对应的护岸挡浪墙的高程须明显加高;利用部分海岛地形斜坡高地作为厂区护岸一部分时,原状海岛地形斜坡高地处的波浪爬高效应明显,须加高邻近护岸挡浪墙的高程。     

生物浮岛对长湖水质和浮游植物的影响

为探索治理长湖水体富营养化的有效方法,开展生物浮岛对其水质和浮游植物的影响。结果表明,在藻类大量生长的季节(7—9月),浮岛区水体中TN_w、DO、TSS、Chl-a含量以及TLI值较对照区有所下降,下降幅度在6%~62.3%,其中以Chl-a含量下降最明显;浮岛上下游区域浮游植物优势类群存在差异性,而且下游的浮游植物细胞丰度、均匀度指数和Shannon-Wiener多样性指数均较上游有所下降。由此可见,生物浮岛能有效吸附长湖水体中N、P等营养元素,对其藻类水华的爆发具有抑制作用,可作为长湖水体原位生态修复的有效手段。     

泽龙湖景观水污染治理及生态修复

为了去除泽龙湖微污染景观水中的氮、磷及有机物等污染成分,采用人工增氧和浮田型生态岛技术对泽龙湖景观水进行了生态修复。结果表明,人工增氧能很好地氧化水中有机物,生态岛水生植物可有效地吸收氮和磷,处理后湖水可达到《地面水环境质量标准》(GB 3838—2002)中的Ⅳ类标准。     

Trends in seabird breeding populations across the Great Barrier Reef

The Great Barrier Reef is an iconic ecosystem, known globally for its rich marine biodiversity that includes many thousands of tropical breeding seabirds. Despite indications of localized declines in some seabird species from as early as the mid-1990s, trends in seabird populations across the reef have never been quantified. With a long history of human impact and ongoing environmental change, seabirds are likely sentinels in this important ecosystem. Using 4 decades of monitoring data, we estimated site-specific trends for 9 seabird species from 32 islands and cays across the reef. Trends varied markedly among species and sites, but probable declines occurred at 45% of the 86 species-by-site combinations analyzed compared with increases at 14%. For 5 species, we combined site-specific trends into a multisite trend in scaled abundance, which revealed probable declines of Common Noddy (Anous stolidus), Sooty Tern (Onychoprion fuscatus), and Masked Booby (Sula dactylatra), but no long-term changes in the 2 most widely distributed species, Greater Crested Tern (Thalasseus bergii) and Brown Booby (Sula leucogaster). For Brown Booby, long-term stability largely resulted from increases at a single large colony on East Fairfax Island that offset declines at most other sites. Although growth of the Brown Booby population on East Fairfax points to the likely success of habitat restoration on the island, it also highlights a general vulnerability wherein large numbers of some species are concentrated at a small number of key sites. Identifying drivers of variation in population change across species and sites while ensuring long-term protection of key sites will be essential to securing the future of seabirds on the reef.     

Evolution of Nesting Height in an Endangered Hawaiian Forest Bird in Response to a Non‐Native Predator

Abstract: The majority of bird extinctions since 1800 have occurred on islands, and non‐native predators have been the greatest threat to the persistence of island birds. Island endemic species often lack life‐history traits and behaviors that reduce the probability of predation and they can become evolutionarily trapped if they are unable to adapt, but few studies have examined the ability of island species to respond to novel predators. The greatest threat to the persistence of the Oahu Elepaio (Chasiempis ibidis), an endangered Hawaiian forest bird, is nest predation by non‐native black rats (Rattus rattus). I examined whether Oahu Elepaio nest placement has changed at the individual and population levels in response to rat predation by measuring nest height and determining whether each nest produced offspring from 1996 to 2011. Average height of Oahu Elepaio nests increased 50% over this 16‐year period, from 7.9 m (SE 1.7) to 12.0 m (SE 1.1). There was no net change in height of sequential nests made by individual birds, which means individual elepaios have not learned to place nests higher. Nests ≤3 m off the ground produced offspring less often, and the proportion of such nests declined over time, which suggests that nest‐building behavior has evolved through natural selection by predation. Nest success increased over time, which may increase the probability of long‐term persistence of the species. Rat control may facilitate the evolution of nesting height by slowing the rate of population decline and providing time for this adaptive response to spread through the population.     

Using Distance from Putative Source Woodlots to Predict Occurrence of Forest Birds in Putative Sinks

Abstract:  For some species of forest-breeding birds, productivity is much higher in large forest fragments than in small forest fragments and is higher than the level needed to replace individuals within the fragment (sources). Thus large forest fragments potentially provide excess individuals to neighboring small fragments where productivity is much lower and not adequate for replacement (sinks). We used occurrence data and distances between putative sources and sinks for four species of forest birds with this pattern of demography in large and small forest fragments to predict occupancy in small fragments. For the Ovenbird (  Seiurus aurocapilla ), Wood Thrush (  Hylocichla mustelina ), Veery ( Catharus fuscescens ), and Rose-breasted Grosbeak ( Pheucticus ludovicianus ), distance from large woodlots was a significant predictor of occurrence in small woodlots. Distance from large woodlots did not predict occupancy of Red-eyed Vireos (  Vireo olivaceus ), a species with no apparent difference in productivity in relation to fragment size. Neither vegetation features nor area of the small woodlots adequately explained patterns of occupancy for any species. These results suggest that maintenance of large, productive forest fragments benefit regional occurrence of forest-breeding birds by providing individuals to neighboring small woodlots. Limited reproduction in these small woodlots means that they may act as a reservoir for excess individuals in the case of catastrophic events that result in vacancies in source woodlots. Conservation and sound forest management of small forests should be directed particularly toward those closer to large regional forests.     

Participatory GIS for strengthening transboundary marine governance in SIDS

In this paper we explore the challenges involved in engaging the full range of stakeholders needed for effective marine resource management in the transboundary Grenadine Islands shared by the small island developing States (SIDS) of Saint Vincent and the Grenadines and Grenada. The study describes the ways stakeholders were engaged in the development of participatory geographic information systems (PGIS), both in terms of the research approach (process) and the final geodatabase (product); it illustrates how the approach provides a practical means to strengthen aspects of marine governance, particularly in a SIDS context. We found that PGIS can provide a foundation for ecosystem‐based transboundary marine governance. The advantages of this approach are two‐fold: it provides the fullest possible range of information as input for the management of marine resources and it engages the stakeholders. This engagement takes several forms: capacity to participate in research; ownership of information produced; increased stakeholder understanding; empowerment through access to information; capacity to interact with other stakeholders for information and problem‐solving; and competence to participate in actual governance processes. Lastly, we discuss considerations for other practitioners contemplating using PGIS, particularly those working in similar resource‐limited SIDS environments.     

Early development of vegetation in restored dune plant microhabitats on a nourished beach at Ocean City, New Jersey

Topography and vegetation of restored dunes on a developed barrier island were examined after a large-scale beach nourishment project. Restoration began in 1993 using sand-trapping fences andAmmophila breviligulata Fern. plantings. Subsequent growth of dunes was favored by installing new fences and suspending beach raking to accommodate nesting birds. Plant species richness, percent cover of vegetation, and height ofA. breviligulata were sampled in 1999 on seven shore perpendicular transects in six dune microhabitats (backdune, primary crest, mid-foredune, swale, seaward-most fenced ridge, incipient dune on the backbeach). A total of 26 plant taxa were found at all seven sites. Richness and percent cover were greatest in the backdune and crest, especially in locations that predated the 1992 nourishment. Richness was greater where fences enhanced stabilization. Fences initially compensate for time and space and allow vegetation to develop rapidly, but maintenance nourishment is required to protect against wave erosion and ensure long-term viability of habitat. An expanded environmental gradient is an option, where beach nourishment provides space for a species-rich crest and backdune to develop, while the incipient dune remains dynamic. Options where space is restricted include a dynamic, full-sized seaward section of a naturally functioning dune (truncated gradient) or a spatially restricted sampler of a wider natural dune (compressed gradient) maintained using fences. Expanded and truncated gradients may become self-sustaining and provide examples of natural cycles of change. Compressed gradients provide greater species richness and flood protection for the available space, but habitats are vulnerable to erosion, and resident views may be impaired.     

上海崇明岛近三年PM_(2.5)浓度变化特征与气象条件的关系

利用2011年1月~2014年2月上海崇明岛地区颗粒物(PM_(2.5)、PM_(10))的连续监测资料,研究了PM_(2.5)总体分布、季节变化、日变化及浓度频率分布规律,初步分析了逆温、相对湿度、风向风速等气象要素对颗粒物浓度的影响。结果表明:2011~2013年该地区PM_(2.5)平均值分别为24.7,33.6和28.3μg/m~3,均低于PM2.5的年平均浓度限值35μg/m~3,细粒子污染程度较轻。PM_(2.5)浓度日变化幅度不大,呈微弱的单峰型分布,9∶00左右达到一天中的最大值,15∶00左右达到最小值。PM_(2.5)浓度的季节分布特征明显,呈现出冬季春季秋季夏季,一般情况下5月份PM_(2.5)月均浓度值最高,8月份浓度最低。PM_(2.5)日平均浓度有57.9%达到国家空气质量一级标准,有93.4%达到国家空气质量二级标准,超标率为6.6%。对PM_(2.5)与各气象要素进行分析后发现:PM_(2.5)质量浓度在逆温层结稳定、风速小、高湿以及近地面盛行西北到西风这样的静稳天气条件配合高空西北方向上的外来污染物输送,容易造成高浓度的PM_(2.5)污染。