Trophic network model of the Northern Adriatic Sea: Analysis of an exploited and eutrophic ecosystem     

Alberto Barausse  Alessandro Duci  Carlotta Mazzoldi  Yuri Artioli  Luca Palmeri 《Estuarine, Coastal and Shelf Science》2009,83(4):577-590

A quantitative model of the trophic network of Northern Adriatic Sea marine ecosystem during the 1990s has been constructed, with the goal of analysing its trophic structure, identifying the key trophic groups and assessing the anthropogenic impacts on the ecosystem using the Ecopath modelling protocol. The Northern Adriatic Sea is an eutrophic, shallow basin, and one of the most heavily fished areas in the Mediterranean Sea. The network aggregation into discrete trophic levels sensu Lindeman shows that low trophic levels dominate biomass and energy flows, with 40% of the total system throughput flowing out from trophic level 2. Instead, upper trophic levels appear bottom-up controlled, highly depleted and not exerting any control on the trophic network, as shown by mixed trophic impact-based analyses. Microbial loop is comparable to grazing with respect to the magnitude of flows involved, as 66% of the trophic network flows originate from detritus, which is mainly consumed by bacteria. Key trophic groups are plankton groups, macro-crustaceans and detritus, and other r-selected organisms like squids and small pelagics, which have a great influence on the ecosystem. In particular, zooplankton acts as a bottleneck for energy flows, limiting the energy from the low trophic levels effectively reaching the upper food web. The high pelagic production caused by eutrophication sustains high fishery landings and impressive discard quantities, as well as the benthic compartment. Overall, the ecosystem appears quite productive and in a stressed and developmental status. Model results and comparisons with few existing historical data suggest that the low maturity and stressed state of the Northern Adriatic Sea are not only due to natural characteristics, but mainly to anthropogenic pressures.  相似文献   

MAPGIS在北川县“5·12”震后地质灾害调查与评价数据库建设中的应用     

董延旭  陈朝镇  张新合  王建华  刘昊 《中国地质灾害与防治学报》2010,21(2):77-83

"5·12"汶川特大地震给北川县造成重大灾害损失,在开展震后地质灾害调查与评价项目的制图和建库过程中,存在大量的遥感图像、矢量与栅格图形数据以及属性数据需要采集、编辑、储存、入库、分析、查询和更新。本文以MAPGIS6.7为基础,在GPS与RS技术辅助支持下,系统地进行震后地质灾害空间数据和属性数据地采集、编辑、建库、分析和成果输出;并在此基础上总结了基于MAPGIS的震后地质灾害多源数据建库方法和实现技巧,从而实现地质灾害调查数据库规范化管理,满足了震后地质灾害区划评价、专题地图制作和灾后重建规划等对地质灾害信息的要求,为政府有关部门的灾后重建决策提供技术支持。  相似文献   

Photometric distances to dark clouds: cometary globule CG 12     

G. Maheswar  P. Manoj  H. C. Bhatt 《Monthly notices of the Royal Astronomical Society》2004,355(4):1272-1282

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Differences between cropland and rangeland MODIS phenology (start-of-season) in Mali     

《International Journal of Applied Earth Observation and Geoinformation》2014

Start-of-season data are more and more used to qualify the land surface phenology trends in relation with climate variability and, more rarely, with human land management. In this paper, we compared the phenology of rangeland vs cropped land in the Sahel belt of Africa, using the only currently available global phenology product (MODIS MCD12Q2 – Land Cover Dynamics Yearly), and an enhanced crop mask of Mali. The differences in terms of start-of-season (SOS) are spatially (north south gradient), and temporally (10 years, 2001–2009) analyzed in bioclimatic terms. Our results show that globally the MODIS MCD12Q2 SOS dates of croplands and rangelands differ, and that these differences depend on the bioclimatic zone. In Sahelian and Guinean regions, cropland vegetation begins to grow earlier than rangeland vegetation (8-day and 4-day advance, respectively). Between, in the Sudanian and Sudano-Sahelian parts of Mali, rangeland vegetation greens about one week earlier than croplands. These results are discussed in the context of the land surface heterogeneity at MODIS scale, and in the context of the natural vegetation ecology. These results could help interpreting phenological trends in climate change analysis.  相似文献   

NEW PUBLICATIONS     

《The Professional geographer》2013,65(1):22-25

Ten Years o f Physicogeographic Research in Hungary

Antarctic Snow and Ice Studies  相似文献   

球等鞭金藻中Δ12脂肪酸去饱和酶基因的克隆与功能鉴定     

韩笑天  王帅  郑立  刘万顺 《海洋学报(英文版)》2019,38(2):107-113

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Source of major ions from an ice core of the No. 12 Glacier in Laohugou Valley, Qilian Mountain   总被引：1，自引：1，他引：0  

XiaoQing Cui  JiaWen Ren  Xiang Qin  WenTao Du  WeiJun Sun  GuangMingYu  XiaoXiang Wang  WeiZhen Sun 《寒旱区科学》2010,2(6):0522-0528

In June 2006,a 20.12 m shallow ice core was recovered from an elevation of 5,040 m in the northern branch firn basin of No.12 Glacier,Great Snow Mountain,in the western part of Qilian Mountain,China.Isotopes(δ 18 O),major soluble ions,and radionuclide(β-activity) measurements from the ice core revealed a 46-year record(1960-2006).In this paper,the method of sea-salt ion tracer,correlation analysis and trend analysis were used in this research to confirm the source of the chemical composition.The correlation analysis and HYSPLIT backward trajectory analysis suggests that atmospheric soluble dust species dominate the chemical signature.  相似文献   

祁连山老虎沟12号冰川雷达测厚和冰下地形特征研究   总被引：3，自引：3，他引：0  

王玉哲  任贾文  秦翔  刘宇硕  张通  陈记祖  李亚炜  秦大河 《冰川冻土》2016,38(1):28-35

冰川地形是构建冰川流动模型的基础,对于认识冰川响应气候变化的动力机制具有重要意义.在2009年和2014年消融季,使用探地雷达对祁连山老虎沟12号冰川进行了厚度测量和冰下地形观测,获得了沿冰川中流线和多条横剖面的厚度资料,并对中流线上的厚度分布特征和槽谷形态进行了研究.研究结果表明,东、西支冰川的平均厚度分别为190m和150m,东支冰川冰下地形起伏大于西支,支冰川的表面坡度都较缓和.东、西支冰川进入汇合区时厚度分别为122m和157m,由于支冰川的横向挤压和汇流,汇合区中部冰川厚度增加到162m.冰川槽谷形态具有空间差异,东、西支冰川槽谷形态近似于对称的V型,但是在冰川汇合区,槽谷底部变宽,边坡变缓,发育有不对称槽谷.  相似文献   

祁连山老虎沟12号冰川微粒在沉积后过程的变化特征     

余光明  徐建中  康世昌  任贾文  孙维君  崔晓庆  王磊 《冰川冻土》2014,36(6):1394-1402

2008年10月和2009年10月在祁连山老虎沟12号冰川积累区采集了2个雪坑样品, 通过样品中δ¹⁸O、可溶性离子、不溶性微粒的变化特点划分了雪坑季节. 2008年雪坑季节变化信号明显, 而2009年雪坑不明显, 微粒浓度、Ca²⁺与Mg²⁺含量在春季较高. 离子平衡、pH值、电导率及同期气象记录观测资料均显示, 2009年雪坑受淋溶影响较大. 淋溶强烈时, 受融水造成的粉尘溶解及离子淋溶的影响, 雪坑中微粒与Ca²⁺、Mg²⁺变化趋势不甚一致; 与Ca²⁺相比, Mg²⁺变化能够较好表征微粒的变化; d>5 μm的微粒可能更易于溶解迁移. 通过分析室内雪冰样品在液态下的变化, 发现伴随静置过程微粒的质量浓度呈下降的趋势, 期间Ca²⁺、Mg²⁺却呈现增加的变化, 可能与碳酸盐矿物的溶解有关.  相似文献   

Energy‐Dispersive X‐Ray Fluorescence Spectrometric Determination of Phosphate in Water Samples via a 12‐Molybdophosphate–Crystal Violet Complex          下载免费PDF全文

Katarzyna Pytlakowska 《洁净——土壤、空气、水》2015,43(11):1475-1480

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