广东佛山机场鸟类群落生态及鸟撞预防的研究

通过对佛山机场及附近6种生境的6条样带的调查,记录到有鸟类49种,分属10目23科.重要性值分析表明,最重要的种类6种,即池鹭、白鹭、小白腰雨燕、家燕、金腰燕、白头鹎.按鸟类的生境分布系数划分,广性分布有16种,占总种数的32.7%,构成了佛山机场各生境鸟类群落组成的主体.根据鸟类习性及其栖息生境的特点分析,提出预防鸟撞事件发生采取的对策措施.表1参10     

重庆库区不同海拔段繁殖鸟类群落的物种多样性

1996~1997年,对三峡工程重庆库区的鸟类群落的物种组成和种群数量进行了调查,共调查记录库区繁殖鸟类12目40科170种,数量17326只,其中留鸟有104种,占繁殖鸟总数的61.2%,夏侯鸟66种,占38.8%.用秩-多度曲线对不同海拔段的繁殖鸟类群落进行多样性分析的结果显示:1)秩-多度曲线方法的结果比Shannon-Wiener等物种多样性指数更直观,能更全面地反映多样性状况,该曲线可以对不同群落或相同群落在不同时间的物种多样性进行比较,是分析生物多样性的一种最直观的方法;2)人类干扰是影响各海拔段繁殖鸟类群落物种多样性的主要因素,人类干扰越强烈,鸟类群落物种多样性越低.图2表3参20     

A Comparison of Landscapes Occupied by Increasing and Decreasing Populations of Grassland Birds

Abstract:  For several decades, many grassland bird species have been declining in abundance throughout the Midwest and Great Plains regions of the United States, possibly due to loss of natural grassland habitat and increasing urbanization. I used 20 years of data from the North American Breeding Bird Survey to identify increasing, decreasing, and stable populations of 36 grassland-nesting bird species. I characterized the immediate landscape (circle with radius = 30 km) surrounding each population based on data from the National Resources Inventory. For each landscape, I calculated the proportion of eight different land-cover types: restored grassland, rangeland, cultivated cropland, pasture, noncultivated cropland, forest, urban land, and water. Using a null model, I compared landscape composition of increasing, decreasing, and stable populations. As predicted on the basis of the habitat preferences of grassland birds, increasing populations inhabited landscapes that contained significantly more restored grassland and rangeland but significantly less forest land and urban land than landscapes inhabited by decreasing populations. There was no significant difference in the proportion of cropland within the landscapes of increasing and decreasing populations, although cropland composed a large proportion (>30%) of many landscapes. In contrast, restored grassland typically composed a very small proportion (<3.5%) of total land cover, yet it was significantly more common in the landscapes of increasing than decreasing populations. These results suggest that grassland birds may benefit from government initiatives, such as the Conservation Reserve Program, that promote the restoration of grassland at a landscape scale.     

昆明(巫家坝)国际机场鸟害防治研究

防治机场鸟撞，应遵从一般生态学原理，一方面尽可能改变机场内各种动物的有利栖息环境，另一方面从生态系统的食物链结构中，减少或切断食物链的连接关系，从而减少鸟类数量，减少鸟类对飞机飞行安全的威胁。     

太行山低山丘陵区鸟类种群动态及招引工程效果初报

本文从太行山试区的气候、土壤、植被等状况，深入分析了该试区各种植物群落对招鸟的作用、鸟类群落的季节变化和演替原因，并就人工巢箱招鸟和环境生态改变对招鸟效果等项进行了探讨。初步查明试区内共有鸟类１１目２４科４５属，其中雀形目占多数。     

农药对禽鸟的毒性与评价

测定了甲基异柳磷等四种农药对鹌鹑的急性和蓄积毒性，并作出了安全性评价。结果表明，甲基异柳磷和嘧啶氧磷属高毒级农药，克草胺中毒级，单甲脒低毒级。蓄积试验表明，除嘧啶氧磷为中等蓄积外，其余农药均属轻度蓄积。     

A Spatially Explicit Decision Support Model for Restoration of Forest Bird Habitat

Abstract:  The historical area of bottomland hardwood forest in the Mississippi Alluvial Valley has been reduced by >75%. Agricultural production was the primary motivator for deforestation; hence, clearing deliberately targeted higher and drier sites. Remaining forests are highly fragmented and hydrologically altered, with larger forest fragments subject to greater inundation, which has negatively affected many forest bird populations. We developed a spatially explicit decision support model, based on a Partners in Flight plan for forest bird conservation, that prioritizes forest restoration to reduce forest fragmentation and increase the area of forest core (interior forest >1 km from "hostile" edge). Our primary objective was to increase the number of forest patches that harbor >2000 ha of forest core, but we also sought to increase the number and area of forest cores >5000 ha. Concurrently, we targeted restoration within local (320 km²) landscapes to achieve ≥60% forest cover. Finally, we emphasized restoration of higher-elevation bottomland hardwood forests in areas where restoration would not increase forest fragmentation. Reforestation of 10% of restorable land in the Mississippi Alluvial Valley (approximately 880,000 ha) targeted at priorities established by this decision support model resulted in approximately 824,000 ha of new forest core. This is more than 32 times the amount of core forest added through reforestation of randomly located fields (approximately 25,000 ha). The total area of forest core (1.6 million ha) that resulted from targeted restoration exceeded habitat objectives identified in the Partners in Flight Bird Conservation Plan and approached the area of forest core present in the 1950s.     

广州南沙湿地鸟类群落组成、多样性和保护策略

采用系统抽样技术和样带法，对广州南沙地区湿地鸟类群落进行了研究，共记录到95种，隶属15目34科68属。国家Ⅱ类保护种类11种，广东省重点保护鸟类16种。东洋界鸟类44种，古北界种类41种，广布型种类10种。鸟类群落多样性以近岸及海岸湿地最高，多样性指数3．4250，均匀性指数0．8711。南沙地区湿地鸟类资源丰富，分析了鸟类的重要性和稀缺性，开发建设必须正确处理湿地鸟类保护的关系，实现生态环境可持续发展，并提出厂相应的保护措施。     

Estimator bias and efficiency for adaptive cluster sampling with order statistics and a stopping rule

Practical problems facing adaptive cluster sampling with order statistics (acsord) are explored using Monte Carlo simulation for three simulated fish populations and two known waterfowl populations. First, properties of an unbiased Hansen-Hurwitz (HH) estimator and a biased alternative Horvitz-Thompson (HT) estimator are evaluated. An increase in the level of population aggregation or the initial sample size increases the efficiencies of the two acsord estimators. For less aggregated fish populations, the efficiencies decrease as the order statistic parameter r (the number of units about which adaptive sampling is carried out) increases; for the highly aggregated fish and waterfowl populations, they increase with r. Acsord is almost always more efficient than simple random sampling for the highly aggregated populations. Positive bias is observed for the HT estimator, with the maximum bias usually occurring at small values of r. Secondly, a stopping rule at the Sth iteration of adaptive sampling beyond the initial sampling unit was applied to the acsord design to limit the otherwise open-ended sampling effort. The stopping rule induces relatively high positive bias to the HH estimator if the level of the population aggregation is high, the stopping level S is small, and r is large. The bias of HT is not very sensitive to the stopping rule and its bias is often reduced by the stopping rule at smaller values of r. For more aggregated populations, the stopping rule often reduces the efficiencies of the estimators compared to the non-stopping-rule scheme, but acsord still remains more efficient than simple random sampling. Despite its bias and lack of theoretical grounding, the HT estimator is usually more efficient than the HH estimator. In the stopping rule case, the HT estimator is preferable, because its bias is less sensitive to the stopping level.