基于生态足迹的陕西省适度人口研究   总被引：1，自引：0，他引：1  

徐坡  韩新海 《地下水》2011,33(3):177-181

一个区域生态适度人12的确定取决于区域生态承载力与区域人12对生态资源的需求.首先介绍了生态足迹模型的基本概念和计算方法,其次计算了陕西省1990-2004年的生态足迹和实际利用的生态承载力,并在此基础上估算了陕西省1990～2004年的态适度人口.结果表明:在1990～1998年,陕西省年生态适度人口由2898.9万...  相似文献   

岩体生长过程的传热学制约及其岩浆熔融效应     

白俊豪  朱丹  黄智龙 《矿物岩石地球化学通报》2011,30(2):204-209

研究岩体生长过程的传热学制约及其引起的岩浆熔融效应能为我们认知地壳演化提供新的思路和手段。本文从年代学和测量技术两个方面综述岩体(或者岩浆房)逐渐长大的证据,然后运用Heat-3D程序简单模拟了Mount Stuart和Tenpeak岩体逐渐长大过程的传热学制约,结合年代学证据证明Mount Stuart岩体是逐渐长大的,并且每期次岩浆之间有很长的时间间隔,而Tenpeak岩体的长大可能是岩浆连续不断侵入或者各期次岩浆的短时间间隔所致。岩体逐渐长大过程引起的岩浆熔融效应是很明显的,模拟实验表明,岩浆多期次侵入地壳时生成的酸性熔体量更接近于地质观察事实。  相似文献   

模拟酸雨对东北地区农作物生长、生理及品质的影响   总被引：1，自引：0，他引：1  

孟赫  董德明  王菊  张胜楠  侯洁  杨萌尧  房春生 《吉林大学学报(地球科学版)》2011,41(3):866-872

通过模拟试验,研究不同pH模拟酸雨胁迫对农作物(小白菜)生长、生理及品质的影响,量化不同pH酸雨对小白菜的影响程度。试验结果表明:小白菜植株受害与pH密切相关,酸性越强,胁迫影响越显著,受害程度越重。随着酸雨酸性增强,小白菜生长受抑,生物量、株高等明显降低,食部鲜质量、干质量受影响程度比根部鲜质量、干质量大。在酸雨胁迫下,小白菜游离氨基酸总量、可溶性糖、可溶性蛋白质和维生素C含量均出现不同程度的降低,且酸性越强,受影响幅度越大,弱酸条件下可在一定程度上促进营养物质的合成。酸雨可抑制叶绿素类与类胡萝卜素合成,影响光合作用,最终导致产量降低、品质下降。  相似文献   

Genetic variability of half-smooth tongue sole Cynoglossus semilaevis populations using microsatellite markers     

LIU Yunguo  GUO Yinghui  LIU Shuaishuai  LI Junfeng  YE Naihao 《海洋学报(英文版)》2011,30(3):76-83

Ten highly variable microsatellite loci were performed in order to evaluate the genetic variability of wild and hatchery samples of half-smooth tongue sole Cynoglossus semilaevis. A group of 200 genotypes belonging to four wild samples, Laizhou (LZ), Weihai (WH), Qingdao (QD), Rizhao (RZ) and one hatchery sample, Mingbo (MB), were screened. All of the ten microsatellite loci screened in this study showed marked polymorphism. A total of 70 different alleles were observed over all loci. The number of alleles per locus ranged from 4.2 to 10.6. The average of expected and observed heterozygosity ranged from 0.67 to 0.82, and from 0.77 to 0.87, respectively. A total of 10, 16, 10, 11 and 5 unique alleles each were found in LZ, WH, QD, RZ and MB populations. The effective number of alleles varied from 2.87 for HSTS_7 to 6.83 for HSTS-h. The number of average genotypes ranged from 6.0 for HSTS_a to 15.4 for HSTS_h. As compared with the wild populations, the hatchery population, MB, showed significant genetic changes such as fewer alleles per locus (P <0.05), a smaller number of low frequency alleles (P <0.05), a small number of unique alleles and a small number of genotypes (P <0.05), all indicative of a reduction in genetic diversity.  相似文献   

Effect of UV-B radiation on the population dynamics of the rotifer Brachionus urceus     

WANG Jinhe  FENG Lei  TANG Xuexi 《海洋学报(英文版)》2011,30(2):113-119

The effect of UV-B radiation enhancement at experimental doses of 0.00,0.24,0.48,0.72,0.96,and 1.20 kJ/m 2 on the population dynamics of the rotifer Brachionus urceus feeding on the alga Chlorella sp.was studied under controlled laboratory conditions using clonal culture and life-table techniques.The results show that UV-B radiation treatment significantly shortened the survival time of the rotifer (P <0.05): The longest survival time (336 h) occurred in the control (0.00 kJ/m 2 ) while the shortest (222 h) occurred when exposed to the highest UV-B radiation treatment (1.20 kJ/m 2 ).The fecundity of the rotifer B.urceus was enhanced by the lower UV-B radiation treatment (0.24 and 0.48 kJ/m 2 ) but inhibited by the higher treatments (0.96 and 1.20 kJ/m 2 ).Life expectancy also was obviously affected by UV-B radiation (P <0.05).The highest life expectancy occurred in the control (0.00 kJ/m 2 ),and it became shorter with increasing doses of UV-B radiation.The resutls in the present study indicate that the life expectancy of the rotifer B.urceus can be used as an indicator for UV-B radiation enhancement.  相似文献   

The application of cutting plus waterlogging to control Spartina alterniflora on saltmarshes in the Yangtze Estuary,China     

Lin Yuan  Liquan Zhang  Derong Xiao  Huamei Huang 《Estuarine, Coastal and Shelf Science》2011

Control and eradication of the exotic and invasive plant Spartina alterniflora within the Chongming Dongtan nature reserve, Shanghai, China, is vital for the management and conservation of the saltmarshes. A demonstration project was established using waterlogging and cutting to control this invasive species. Results from 2007 to 2008 showed that, although the managed waterlogging significantly reduced biomass and seed production of S. alterniflora at an early stage, the species subsequently showed rapid adaptation to the long-term waterlogging stress. Thus, managed waterlogging alone was insufficient for the effective eradication of S. alterniflora. However, managed waterlogging for around 3 months, combined with cutting the above-ground part of S. alterniflora at a key stage (flowering period in July), controlled and eradicated the plant successfully. Both the above-ground and below-ground parts of S. alterniflora were killed and the plants began to decompose after 3 months. Furthermore, there was no re-growth of the emergent part of S. alterniflora in the following years. However, once the impounded water was released restoring the natural hydrodynamic regime of the saltmarshes, the seeds and seedlings of S. alterniflora reinvaded the controlled site from the neighboring areas and the S. alterniflora community was re-established. Thus, after eradication of S. alterniflora, control measures should be maintained to prevent the re-establishment of S. alterniflora. The results of this demonstration project indicate a potentially useful and effective approach for the control and management of large-scale invasion by S. alterniflora on saltmarshes in the Yangtze Estuary, China.  相似文献   

Spatial and temporal variability of deep-water algal assemblages in the Northwestern Mediterranean: The effects of an exceptional storm     

Laura Navarro  Enric Ballesteros  Cristina Linares  Bernat Hereu 《Estuarine, Coastal and Shelf Science》2011

There are deep-water populations of the endemic and threatened Mediterranean brown alga Cystoseira zosteroides in the Medes Islands Marine Reserve (NW Mediterranean). Here, the distribution, population structure, individual growth, mortality and recruitment rates of this species over two years are described in relation to the effects of an exceptional storm. We found a high spatial variability in the structure and dynamics of C. zosteroides populations at small geographical scales, suggesting that environmental factors acting at the population level display a key role in population size structure, mortality and recruitment. The elevated mortality rates recorded at some locations (almost 80%) is amongst the highest recorded for perennial algae as a consequence of a single storm, emphasizing the importance of episodic catastrophic events in the maintenance of these deep-water, slow-growing populations. These findings are of particular importance not only to fully understand the ecology of C. zosteroides, but also for its conservation.  相似文献   

Growth and grazing rate dynamics of major phytoplankton groups in an oligotrophic coastal site   总被引：1，自引：0，他引：1  

Andrés Gutiérrez-Rodríguez  Mikel Latasa  Renate Scharek  Ramon Massana  Gemma Vila  Josep M. Gasol 《Estuarine, Coastal and Shelf Science》2011

There has been more attention to phytoplankton dynamics in nutrient-rich waters than in oligotrophic ones thus requiring the need to study the dynamics and responses in oligotrophic waters. Accordingly, phytoplankton community in Blanes Bay was overall dominated by Prymnesiophyceae, remarkably constant throughout the year (31 ± 13% Total chlorophyll a, Tchl a) and Bacillariophyta with a more episodic appearance (20 ± 23% Tchl a). Prasinophyceae and Synechococcus contribution became substantial in winter (Prasinophyceae = 30% Tchl a) and summer (Synechococcus = 35% Tchl a). Phytoplankton growth and grazing mortality rates for major groups were estimated by dilution experiments in combination with high pressure liquid chromatography and flow cytometry carried out monthly over two years. Growth rates of total phytoplankton (range = 0.30–1.91 d⁻¹) were significantly higher in spring and summer (μ > 1.3 d⁻¹) than in autumn and winter (μ ∼ 0.65 d⁻¹) and showed a weak dependence on temperature but a significant positive correlation with day length. Microzooplankton grazing (range = 0.03–1.4 d⁻¹) was closely coupled to phytoplankton growth. Grazing represented the main process for loss of phytoplankton, removing 60 ± 34% (±SD) of daily primary production and 70 ± 48% of Tchl a stock. Chla synthesis was highest during the Bacillarophyceae-dominated spring bloom (Chl a_synt = 2.3 ± 1.6 μg Chl a L⁻¹ d⁻¹) and lowest during the following post-bloom conditions dominated by Prymnesiophyceae (Chl a_synt = 0.23 ± 0.08 μg Chl a L⁻¹ d⁻¹). This variability was smoothed when expressed in carbon equivalents mainly due to the opposite dynamics of C:chl a (range = 11–135) and chl a concentration (range = 0.07–2.0 μg chl a L⁻¹). Bacillariophyta and Synechococcus contribution to C fluxes was higher than to biomass because of their fast-growth rate. The opposite was true for Prymnesiophyceae.  相似文献   

低温对不同规格刺参幼参生长与耗氧率的影响   总被引：1，自引：0，他引：1  

赵斌  李成林  胡炜  吴志宏  谭林涛  王鹏飞 《海洋科学》2011,35(12):88-91

采用实验生态学方法, 选取（0.50±0.07）g（A）、（2.53±0.42）g（B）、（23.87±2.46）g（C）3 种不同规格的刺参（Apostichopus japonicus Selenta）幼参, 设置6℃（I）、8℃（II）、10℃（III）、13℃（IV）4 个不同温度处理组, 分析比较了低温对工厂...  相似文献   

温度对凡纳滨对虾幼体生长、变态和存活率的影响   总被引：1，自引：0，他引：1  

杨章武  卢小宁  郑雅友  李正良 《台湾海峡》2011,30(1):81-85

通过不同水温的比较实验,研究了凡纳滨对虾人工育苗的适宜水温,旨在了解33℃及其以上水温对凡纳滨对虾幼体生长、变态和存活率可能造成的不良影响.实验结果表明,在29、31、33、35℃这4种温度实验组中,33℃组幼体的生长最快.Z1—P15期幼体的存活率以31℃组的最高（为29.8%）,其次是33℃组（为20.9%）,35℃组的最低（为4.7%）.实验过程中31℃组幼体的活力状态最佳、最稳定.因此,31℃左右是凡纳滨对虾幼体生长、发育的适宜水温.考虑到33℃组幼体的总存活率虽然低于31℃组,但其具有生长较快的优势,因此可认为目前凡纳滨对虾人工育苗普遍采用的31～32℃水温是合适的.  相似文献