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241.
湖北石首天鹅洲湿地旅游资源综合评价 总被引:5,自引:0,他引:5
湿地是地球上水陆相互作用形成的独特生态系统,湿地评价能帮助人们更好地开发和利用湿地资源.通过采用多层次分析法(AHP),对湖北天鹅洲湿地旅游资源的价值进行分层、分权重的评价实践,探讨了一种定性与定量相结合的湿地评价方法,为天鹅洲湿地旅游资源的开发强度和可利用潜力提供指导. 相似文献
242.
Although the genetic and ecological effects of population declines in endangered species have been well studied, little is known of the social consequences. Changes in signaling behavior may result in disrupted communication and affect both reproductive and conflict‐resolution activities. The North Island Kōkako (Callaeas wilsoni) is an endangered, duetting (i.e., alternating, coordinated singing by mated pairs) songbird endemic to New Zealand temperate rain forests. Scattered populations (approximately 1500 individuals in 13 surviving and 11 translocated populations) in isolated conservation areas of different sizes have been rescued from extirpation and are currently recovering. We examined key song attributes of the Kōkako to assess whether population size or growth rate are related to song complexity, the reduction of which may compromise effective communication. We analyzed song repertoire size and phrase‐type sharing (i.e., Jaccard index of similarity), vocal performance (singing rates, song switching rates, and diversity of phrase types), and song syntactical characteristics (i.e., unpredictability in sequences of phrase types) in surviving and translocated populations (populations of approximately 19–250 territorial individuals). Population size was positively correlated with a population's song repertoire, song diversity, and switching of song phrase types and negatively correlated with shared phrase types and variation in syntactical structure of songs. Population growth rate correlated positively with pair repertoire size, population repertoire size, and singing rates during song bouts. As for solo‐singing species in fragmented landscapes, songs in the fragmented populations of Kōkako appear to be undergoing microevolution as occurs in island colonization events. Our results suggest that vocal changes in small populations could affect population establishment and growth, particularly in multiple‐source translocations. We believe measurement of vocal behavior could be used as a supplement to periodic population censuses to allow more frequent monitoring of population size. Efectos de la Conducta de Canto sobre el Tamaño Poblacional de una Ave Canora Rara 相似文献
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Vehicle collisions with wildlife have the potential to negatively impact species everywhere roads divide natural habitats; this is especially true in areas where roads are a recent addition to the landscape (e.g., in the last decade) and/or where expansion of a road network is underway. This study addresses the impact of traffic fatalities on lava lizards, Microlophus albemarlensis, on the island of Santa Cruz, Galápagos. The main road bisecting the island north to south was added to the island beginning in 1974 but not fully paved until 2000. We assessed impacts occurring due to traffic and vehicle speeds on the island. This study adds impacts to lizard populations to those conducted on birds on Santa Cruz, providing a means to create multi-species recommendations. To quantify impacts to lizard populations, we assessed lizards on randomly chosen transects perpendicular to the road. We used Poisson regression to analyze those data and found a 30% increase in lizard abundance per 100 m distance from the road across vegetation zones. We compared incidence of prior tail loss of road-killed lizards and live animals to comment on additional energetic costs of occupying near-road territories. Tail condition could not be assessed in some road-killed lizards; among those that we could assess, 29% showed evidence of prior tail loss. That rate declined to apparent baseline conditions of only 1% beyond 200 m from the road. By traveling the length of the 40-km road, we identified hot spots for fatalities of both lizards and birds to provide necessary information for developing management and remediation strategies. We offer guidance on Best Management Practices, such as testing overpasses, fencing and underpasses, which might reduce vehicle impacts to lizards from drivers on the current road. This information is essential because of a planned increase in the Santa Cruz road network in areas where lava lizards are most abundant. 相似文献
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依托国家海洋局三沙海洋环境监测中心站,基于激光大气温室气体分析仪(GLA331-GGA),搭建了一套全自动、连续、高精度观测大气CH4的观测系统.通过气团后向轨迹输送特征,结合数值统计方法(局部近似回归法),对西沙永兴岛区域2013年12月~2017年11月期间的观测数据进行了数据筛分和分析.结果显示:西沙海域大气CH4季节变化与北半球大气本底变化状况类似,冬季高、夏季低,年平均增长率约为11.9×10-9,年平均季节振幅为81.1×10-9;其日变化呈现中午低、凌晨高的单周期正弦变化特征;该区域风场数据和气团后向轨迹分析表明:季风是影响该区域CH4浓度变化的最主要因素. 相似文献
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本文通过绿色植物能量转化的生理机能,即光合作用过程中太阳能的投入、转化和产出的内在联系,定量地描述了海南岛各地实际光能利用率;地区性农业生产潜力;潜在光能利用率及其与实际光能利用率的绝对差值。结果表明,全岛实际光能利用率低于全国平均水平,只及一年两熟地区的一半,高值区接近一年一熟地区;潜在光能利用率与世界热带地区差距不大;潜在与实际光能利用率之差全岛平均达5.1%,具有较大的增产潜力。文中还针对海南的实际粗略地探讨了岛内光能利用率不高的原因和提高光能利用率的相应途径。 相似文献