8 research outputs found
石羊河尾闾绿洲的景观变化与生态恢复对策
利用G IS技术和景观结构分析软件FRAG STATS,在对民勤湖区绿洲景观格局动态变化以及土地利用格局的空间转化分析的基础上,从水资源利用以及政策和市场经济等方面分析了湖区景观变化的驱动因素,结果表明:(1)耕地和沙地斑块数量减少,平均斑块面积增加,空间连片趋势加剧;蔓延度指数变大,边缘密度和多样性指数降低;(2)沙地和耕地面积分别增加5171.85 hm2和2640.33hm2,它们的增加以牺牲林、草地为代价;(3)湖区地表水净利用量近10a来降幅达50%,到20世纪90年代后期仅有0.22×108m3,使得地下水净利用量近年来年均高达0.80×108m3;(4)以耐盐性较强的经济作物占绝对优势的单一经济结构,降低了农业生产对市场风险的抵御能力,农户收入急剧下降。通过以上分析,提出了湖区生态恢复途径与措施
朱鹮性别分子鉴定的研究进展
朱鹮(Nipponia nippon)为世界濒危物种,也是国家一级重点保护鸟类。虽然一系列的保护措施显著增加了朱鹮种群规模和分布区域,但近交衰退、低繁殖力和雏鸟高致残率等问题一直制约着朱鹮种群的发展。朱鹮由于雌雄同型,难以从外观区分性别,因此性别鉴定将对其人工繁殖具有重要意义。本文综述了朱鹮性别的分子鉴定方法,主要包括基于性染色体连锁的染色体解旋酶DNA结合蛋白CHD基因及EcoRⅠ片段的PCR鉴定方法,以期进行有效的人工繁育工作,实现对朱鹮种群的保护及规模重建
Effects of different restoration ages on plant diversity and community stability of wetlands in the Yellow River Delta
Ecological restoration is an efficient method to reduce the degradation of natural coastal wetlands.Restoration age has important effects on soil chemical properties and plant community characteristics.However,long-term monitoring on the effects of wetland restoration projects and their underlying mechanism is still limited.Here,we examined the effects of different restoration ages (0,3,7,10,and 19 years) of wetlands on soil properties,plant species diversity,and community stability in the Yellow River Delta.The results showed that soil electric conductivity,available phosphorus concentration,and available potassium concentration decreased with increasing restoration age.However,soil available nitrogen concentration increased during the restoration process.Shannon index,Pielou evenness index,and species richness index of plant communities increased continuously with increasing restoration age,while plant diversity indices were mainly driven by the changes in soil electrical conductivity.In addition,restoration age also promoted plant community stability,which was significantly and negatively related to soil electric conductivity,available phosphorus and available potassium,and positively related to available nitrogen concentration.With the proceeding of restoration,soil environment and plant community structure improved continuously.Therefore,restoration projects can stimulate positive succession of community and improve the stability of coastal wetland ecosystems
Effect of decomposition products of cyanobacteria on<i>Myriophyllum spicatum</i>and water quality in Lake Taihu,China
2003~2015年CERN植物物候观测数据集
中国生态系统研究网络(Chinese Ecosystem Research Network,CERN)植物物候观测数据集是CERN生态站植物物候观测数据综合集成的产物,包含21个生态站2003~2015年660余个物种的物候观测记录。因木本植物和草本植物观测的物候期不同,本数据集被分为木本子集和草本子集。木本子集主要记录了芽开放期、展叶期、开花始期、开花盛期、果实或者种子成熟期、叶秋季变色期和落叶期等物候信息。草本子集则记录了萌动期、开花期、果实或种子成熟期、种子散布期和黄枯期等物候信息。另外,本数据集还包含生态站代码、年份、样地代码、样地名称、样地类别、植物种名、拉丁名等信息。本数据集可以为环境变化、碳循环、植物对环境变化的响应等方面的研究提供数据支持
桃红岭国家级自然保护区梅花鹿种群现状
梅花鹿南方亚种被IUCN濒危物种红皮书列为濒危级,仅分布于安徽南部、江西东北部和浙江西北部,分布区域日益萎缩,分布区之间隔离程度较大。江西桃红岭是该亚种分布区之一,为保护该亚种,1981年成立桃红岭自然保护区,2001年升级为国家级自然保护区。为了解桃红岭野生梅花鹿现生种群数量,评估保护区过去30 a的保护成效,我们于2011年秋季采用直接计数的广义样线法开展梅花鹿种群调查。调查结果表明,保护区内梅花鹿数量为365只,密度为2.92只/km2,近年来梅花鹿种群增长较慢。经过30 a的保护,该保护区自然植被正在演替恢复。然而,当地的顶级植物群落可能并不是梅花鹿的适宜生境。因此,近年来,梅花鹿向保护区外扩散趋势明显,由此带来的各种管理问题值得关注
