气候变化下汉中盆地水稻产量变化研究

深入分析气候变化下汉中盆地水稻产量变化响应,可在进一步探究影响研究区水稻产量主要气象要素的同时,为地方水稻生长期内气象灾害的防控提供科学依据。为了解研究区水稻生长季主要的气象影响因子,文章基于1951—2014年汉中盆地多测站日气温、降水量、积温及气温日较差数据和水稻单产资料分离的气象单产数据,综合运用线性趋势、趋势系数、HP滤波法、Morlet小波分析等方法,在分析汉中盆地水稻气象产量和生长季各气象要素变化趋势的同时,推求了水稻气象产量和各主要气象要素序列的显著周期。研究结果表明：1）近64 a汉中盆地4—9月水稻生长季平均气温和≥10 ℃活动积温变化均呈上升趋势,气温日较差呈下降趋势,降水量变化趋势不明显;2）汉中盆地各气象要素与水稻气象单产的显著周期分析结果显示水稻气象单产第一主周期与各气象要素的第二主周期相对应,均存在13~14 a时间尺度的主周期变化;3）各气象要素对水稻气象产量的影响各异,不同气候背景下影响水稻气象产量的主导气象因素不同。论文研究结果可为汉中盆地水稻生产的优化布局及地方经济社会发展提供参考依据。     

东沙群岛附近海域风候特征分析

目的利用近22年的CCMP(Cross-Calibrated,Multi-Platform)风场资料,对东沙群岛海域的风候特征进行深入研究,为军地海洋建设提供科学依据。方法利用具有高精度的CCMP风场资料,统计分析近22年期间东沙群岛附近海域的风候特征。结果东沙群岛附近海域的海表风速呈"W"状双峰型月变化。峰值出现在11、12和1月期间,海表风速在9 m/s左右,次峰值位于6月,海表风速在6 m/s左右,东沙海域的年平均风速为6.5 m/s。东沙海域的海表风速表现出"U"型日变化特征。东沙附近海域的风速主要分布于3~5级,即3.4~10.7 m/s之间,1月的大风频率明显高于7月。1月和10月,东沙附近海域的风向以NE向为主,7月受西南季风影响显著,风向以S-SW向为主,4月风向则以ENE和SSE向为主。从全年来看,风向以偏东北向为主,S-SW向居其次。在近22年期间,东沙海域的海表风速整体上以0.0424 m/(s·a)的速度显著性逐年线性递增。结论运用高精度的CCMP风场资料,通过统计分析方法得到了东沙群岛海域的风候特征,对军地海战场环境建设具有科学支持作用。     

不同气候类型下植物物候的影响因素综述

植物物候对气候变化非常敏感,可作为环境变化对植物生理活动影响的指示。植物物候的变化不仅可反映和预测全球环境的变化,还对地球物质循环和能量流动过程有着重要的影响。因此,结合植物生长背景,全面分析植物物候影响因素,探究植物物候对气候变化的响应是十分必要的。本文基于不同的气候类型下植物物候的研究,介绍了不同气候类型本身存在的气象、地域差异,总结不同气候类型下植物物候地域性特征;总结了热带亚热带气候、温带气候、寒带气候、高原山地气候4大类气候类型下植物物候变化及影响因素;讨论了当前物候研究的主要问题,并对未来研究进行了展望。综述表明,植物物候响应随气候类型呈现出不一致性,不同气候类型下影响植物物候的关键因素也不同。植物物候研究需结合植物生长环境,综合讨论相关影响因素。     

黄河三角洲湿地保护和油田开发的协调发展

黄河三角洲新生湿地生态系统是黄河强造陆运动和海岸系统蚀退相互作用的产物,在这里雨热同季,形成了天然或人工、长久或暂时的、流动或静止的湿地。黄河三角洲具有自然、经济和社会三大类１８项功能。油气资源的开发对其自然因素、潜在因素和对社会经济价值都有一定的影响,我们在开采石油的同时一定要注意生态保护,加强绿化、污染物排放总量控制、采用先进的开采技术和建立湿地补偿制度。     

中国特大城市水资源消费及其与经济和气候的关系——以北京、上海和广州为例

选取了北京、上海、广州三个不同地理纬度、经济较为发达的代表性城市作为研究对象,应用多项式模型把气候耗水量从水资源消费总量中分离出来,用统计分析的方法探讨三个城市水资源消费变化及其与经济和气候的关系。研究表明:城市万元GDP用水量与经济水平有明显的对数相关关系,一般都随经济水平的提高而不断下降,三个城市中,上海的水资源利用率最高,广州居中,北京最低。温度是影响城市气候耗水量的主要气候因子,在1986—1991年,三个城市的气候耗水量与温度的相关性不明显,自1992年以来,气候耗水量与温度距平值的波动趋势愈来愈密切,这说明随着经济的发展和人民生活水平的提高,城市水资源消费与温度的关系越来越密切。     

森林土壤有机层生化特性及其对气候变化的响应研究进展

森林土壤有机层是指累积在土壤表面未分解到完全分解的有机残余物质,在全球碳循环中具有十分重要的作用和地位.目前有关森林土壤有机层的生态研究主要集中于土壤有机层的凋落物储量、水土保持功能、生物多样性保育功能及其生化特性等,而有关其对气候变化响应的研究报道还相当少见,且已有的研究主要关于土壤有机层的碳源/汇动态等,有关森林土壤有机层生化特性对气候变化响应的研究还相对较少,这与其在全球气候变化中的作用和地位是极不相称的.过去10a中,有关土壤有机层生化特性对气候变化响应的研究主要包括土壤有机层的微生物数量、微生物生物量、呼吸作用、有机物质分解动态(凋落物分解)、酶活性等对环境变化的响应等方面.进一步的控制实验研究被认为是相当重要的.参51     

Do these eggs smell funny to you?: an experimental study of egg discrimination by hosts of the social parasite Polyergus breviceps (Hymenoptera: Formicidae)

Social parasites exploit the behaviours of other social species. Infiltration of host systems involves a variety of mechanisms depending on the conditions within the host society and the needs of the social parasite. For many species of socially parasitic ants, colony establishment entails the usurpation of colonies of other species. This frequently involves the eviction or death of the host colony queen and the subsequent adoption of the invading queen. The social parasite queen achieves host worker acceptance by either manipulating the nest-mate recognition processes of the host or undergoing chemical modification. Little is known, however, about how host workers respond to social parasite eggs or whether host species defend against brood parasitism during parasite invasions. Host species are believed to adopt social parasite offspring because the recent common ancestry between many social parasites and their hosts may grant the sharing of certain characteristics such as chemical cues. Use of multiple host species, however, suggests other processes are needed for the social bond between host and parasite young to form. This study reports the findings of adoption bioassays in which eggs from a slave-maker ant, Polyergus breviceps, were offered to workers of two of its host species from unparasitised or newly parasitised nests to determine whether P. breviceps eggs generally elicit rearing behaviours from multiple host species. Comparisons of parasite egg survival until adulthood with conspecific egg survival reveal that workers of both host species, free-living or newly enslaved, do not typically accept slave-maker eggs. Both host species thus have sufficient discriminatory power to reject social parasite eggs although our hydrocarbon analysis indicates parasite eggs may be adapted to their local host species. Combined these results suggest that host rearing of P. breviceps eggs may reflect an evolutionary equilibrium that is maintained by probability and cost of recognition errors.Communicated by L. Sundström     

Predicting the Impact of Sea-Level Rise on Caribbean Sea Turtle Nesting Habitat

Abstract:  The projected rise in sea level is likely to increase the vulnerability of coastal zones in the Caribbean, which are already under pressure from a combination of anthropogenic activities and natural processes. One of the major effects will be a loss of beach habitat, which provides nesting sites for endangered sea turtles. To assess the potential impacts of sea-level rise on sea turtle nesting habitat, we used beach profile measurements of turtle nesting beaches on Bonaire, Netherlands Antilles, to develop elevation models of individual beaches in a geographic information system. These models were then used to quantify areas of beach vulnerable to three different scenarios of a rise in sea level. Physical characteristics of the beaches were also recorded and related to beach vulnerability, flooding, and nesting frequency. Beaches varied in physical characteristics and therefore in their vulnerability to flooding. Up to 32% of the total current beach area could be lost with a 0.5-m rise in sea level, with lower, narrower beaches being the most vulnerable. Vulnerability varied with land use adjacent to the beach. These predictions about loss of nesting habitat have important implications for turtle populations in the region.