南极普里兹湾临近海域夏季纽鳃樽对浮游植物的摄食研究

于 1 998年 1 2月至 1 999年 1月南极夏季 ,对南大洋普里兹湾临近海域主要被囊类纽鳃樽的数量密度分布进行了现场调查 ,同时于 - 3站对纽鳃樽对浮游植物的摄食率利用肠道色索法和颗粒递减法进行了现场研究。调查结果表明 ,纽鳃樽主要分布于调查海区的浮冰区北部边缘及其以北的开阔水域。在密集区其数量密度高达 2 795ind..1 0 0 0 m- 3,浮冰区几乎没有发现。 - 3站现场摄食实验结果显示 ,纽鳃樽个体肠道色素含量变化范围为 0 .1 4～ 1 .2 7μg.ind.- 1,平均为0 .98μg.ind.- 1。肠道色素法测得的纽鳃樽对浮游植物的摄食率为 7.9μg.ind.- 1d- 1,滤水率为2 81 ind.- 1d- 1。颗粒递减法测得纽鳃樽滤水率为 1 5.3± 4.61 ind.- 1d- 1,比肠道色素法所得结果偏低。虽然由此推算纽鳃樽群体的日摄食量只占浮游植物现存量的 0 .8% ,但是对于初级生产力却有一定的摄食压力 ( 72 .2 % )。     

THE ORAL HISTORY OF GEOGRAPHY∗

Book Reviewed in this article:

Latin America: Case Studies. Richard G. Boehm and Sent Visser

Locality and Rurality: Economy and Society in Rural Regions. Tony Bradley And Philip Lowe

The City and the Grassroots. Manuel Castells

Geopolitics and Conflict in South America. Quarrels among Neighbors. Jack Child

Post-Industrial America: A Geographical Perspective. David Clark

Coastal Research: UK Perspectives. Malcolm W. Clark

A Rural Policy for the EEC? Hugh Clout

Peasant Agriculture in Assam: A Structural Analysis. M. M. Das.

Environmental Change and Tropical Geomorphology. I. Douglas and T. Spencer

Advances in Abandoned Settlement Analysis: Application to Prehistoric Anthrosols in Colombia, South America. Robert C. Eidt

Measuring Culture. Jonathan L. Gross and Steve Rayner

North America: A Human Geography. Paul Guinness and Michael Bradshaw

A Geographical Bibliography for American Libraries. Chauncy D. Harris et al.

Geography and the Urban Environment: Progress in Research and Applications, Vol. VI. D. T. Herbert and R. J. Johnston

Changes in Global Climate: A Study of the Effect of Radiation and Other Factors During the Present Century. K. Ya. Kondrat'ev.

Rural Development and the State: Contradictions and Dilemmas in Developing Countries. David A. M. Lea and D. P. Chaudhri

The Martial Metropolis: U.S. Cities in War and Peace. Roger W. Lotchin

The Climate of the Earth. Paul E. Lydolph.

Weather and Climate. Paul E. Lydolph.

Spatial Divisions of Labor: Social Structures and the Geography of Production. Doreen Massey.

Panorama of the Soviet Union. N. Mikhailov.

Soviet Armenia. K. S. Demirchian.

USSR: Geography of the Eleventh Five-Year Plan Period. K. Spidchenko.

Planung und Verwirklichung der Wiener Ringstrassenzone (Planning and Materialization of the Ringstrasse-Zone of Vienna). Kurt Mollik, Hermann Reining, Rudolf Wurzer.

The American West Transformed: The Impact of the Second World War Gerald D. Nash.

An Overview of the Survey of Income and Program Participation. Dawn Nelson, David McMillen, and Daniel Kasprzyk.

Phenomenology, Science and Geography: Spatiality and the Human Sciences. John Pickles.

Biological Diversification in the Tropics. Ghillean T. Prance

Die Wanderviehwirtschaft im gebirgigen Westen der U.S.A. und ihre Auswirkungen im Naturraum. Gisbert Rinschede.

Social and Economic Aspects of Radioactive Waste Disposal: Considerations for Institutional Management

World-Wide Weather. K. Takahashi

Coastal Geomorphology in Australia. B. G. Thom

Settlement System in Rural India: A Case Study of the Lower Ganga-Yamuna Doab. Ram Chandra Tiwari.

Computer Programming for Geographers. David J. Unwin and John A. Dawson.

Late Quaternary Environments of the Soviet Union. A. A. Velichko, ed. H. E. Wright, Jr. and C. W. Barnosky

Ethics in Planning. Martin Wachs     

牧压梯度下海北高寒草甸土壤速效氮变化特征及其影响因素分析

在青海海北高寒矮嵩草草甸设置封育禁牧(CK)、轻牧(LG)、中牧(MG)和重牧(HG)放牧梯度试验样地, 进行了土壤速效氮变化特征及影响因素的分析. 结果表明: 植物生长期的5-9月, 土壤NH₄⁺-N、NO₃^--N和速效氮(NH₄⁺-N和NO₃^--N之和)含量季节变化明显, 基本表现为植物生长初期高, 末期低. CK、LG、MG和HG条件下, 5-9月0~40 cm土壤NH₄⁺-N平均含量分别为17.62 mg·kg^-1、17.84 mg·kg^-1、18.63 mg·kg^-1和16.67 mg·kg^-1, NO₃^--N平均含量为8.91 mg·kg^-1、8.23 mg·kg^-1、7.99 mg·kg^-1和7.94 mg·kg^-1, 速效氮平均含量为26.53 mg·kg^-1、26.07 mg·kg^-1、26.62 mg·kg^-1和24.61 mg·kg^-1, 基本表现出随放牧强度增大而降低. 土壤速效氮月际变化与地上绿体生物量具有一定的负相关关系, 表明地上生物量越大, 消耗土壤速效氮越趋明显; 与枯落物有一定的正相关关系, 与地下生物量关系不甚明显, 与湿沉降呈现负的相关性. 土壤NH₄⁺-N含量与土壤有机碳有负相关关系, 而NO₃^--N含量与有机碳相关性差, 表明土壤有机碳越高, 土壤NH₄⁺-N消耗越明显.     

不同生态系统CO2通量和浓度特征分析研究

本文利用1993～1994年日本国家农业环境研究所与中国科学院沙漠研究所合作在内蒙古奈曼地区实测的7种不同生态系统（沙丘、轻度放牧草原、中度放牧草原、重度放牧草原、无放牧草原、玉米田和大豆田）的净辐射、土壤热通量、两个高度的CO2浓度、温度、湿度和风速等资料,采用空气动力学方法,计算了CO2通量及其与环境和人为干扰因子的关系,并分析了不同下垫面的光合作用特征. 结果表明：各种下垫面CO2通量的共同特点是：在白天,CO2通量和梯度的输送方向是从大气向植被,在中午（11～13时）输送达到负的最大值; 在夜间,CO2通量和梯度输送方向与白天相反,是从植被向大气,在早晨（3～5时）达到正的最大值. 植被覆盖率及生物量不同的下垫面光合作用强度有明显差异,天气状况对光合作用也有一定影响.     

Comparison of benthic and pelagic suspension feeding in shallow water habitats of the Northeastern Baltic Sea

Combining field experiments with the biomass distribution data of dominant suspension feeders we compared the benthic and pelagic suspension feeding rates in shallow non-tidal brackish water coastal habitats. We found that pelagic grazing exceeded benthic grazing in almost all cases, on average from 14 to 4819 times depending on the site. Benthic grazing rates were related to site-specific environmental parameters and showed no relationship with water chlorophyl a (Chl a ) content, whereas pelagic grazing rates varied both spatially and temporally and were related to water Chl a content. Our results indicate that in several shallow coastal habitats, pelagic suspension feeding substantially exceeds benthic suspension feeding. This suggests that pelagic recycling is higher than the amounts of energy redirected from pelagic to benthic food webs by benthic suspension feeders. These results increase our knowledge of the energy flows in coastal ecosystems.