ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Monograph available for loan

Principles of lake sedimentology (2002)

Hakanson, Lars ; Jansson, Mats

Caldwell, NJ : Blackburn Pr.

add to mindlist on the mindlist

Details Availability

Call number: 9/M 02.0445

Type of Medium: Monograph available for loan

Pages: X, 316 S.

ISBN: 1930665547

Classification:

Sedimentology

Language: English

Location: Reading room

Branch Library: GFZ Library

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

BOOK

Link to Library Catalog

S·F·X

2

Electronic Resource

A mass-balance model for phosphorus in lakes accounting for biouptake and retention in biota (2003)

Håkanson, Lars ; Ostapenia, Alexander P. ; Boulion, Viktor V.

Oxford, UK : Blackwell Science Ltd

Freshwater biology 48 (2003), S. 0

add to mindlist on the mindlist

Details

ISSN: 1365-2427

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Biology

Notes: SUMMARY 1. A new mass-balance model was developed to predict phosphorus fluxes to, within and from lakes and lake concentrations of phosphorus.2. The model is driven by data easily accessed from standard monitoring programmes or maps, so it should be useful in many contexts of lake management.3. The phosphorus model gives seasonal (weekly) variations and accounts for all fundamental abiotic/biotic interactions and feedbacks for lakes in general for phosphorus. The model has been developed within the framework of a more comprehensive ecosystem model, LakeWeb, which accounts for production values and biomasses of nine functional groups of organisms (phytoplankton, bacterioplankton, herbivorous and predatory zooplankton, prey and predatory fish, zoobenthos, macrophytes and benthic algae).4. The LakeWeb-model has been critically tested in a wide limnological domain and shown to predict very well. By using this model, it is possible for the first time to predict realistic values of biouptake and retention of phosphorous in biota in lakes on a weekly basis.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1046/j.1365-2427.2003.01057.x

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

3

Electronic Resource

Managing the Post-acquisition Integration Process: How the Human Iintegration and Task Integration Processes Interact to Foster Value Creation (2000)

Birkinshaw, Julian ; Bresman, Henrik ; Håkanson, Lars

Oxford, UK and Boston, USA : Blackwell Publishers Ltd

Journal of management studies 37 (2000), S. 0

add to mindlist on the mindlist

Details

ISSN: 1467-6486

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Economics

Notes: The paper reports a study of the post-acquisition integration process in three foreign acquisitions made by Swedish multinationals. Detailed interview data and questionnaire responses in both acquiring and acquired firms are presented. The sub-processes of task integration and human integration are separated out and it is shown that effective integration in these cases was achieved through a two-phase process. In phase one, task integration led to a satisficing solution that limited the interaction between acquired and acquiring units, while human integration proceeded smoothly and led to cultural convergence and mutual respect. In phase two, there was renewed task integration built on the success of the human integration that had been achieved, which led to much greater interdependencies between acquired and acquiring units.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1111/1467-6486.00186

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

4

Electronic Resource

Management criteria for lake ecosystems applied to case studies of changes in nutrient loading and climate change (2003)

Håkanson, Lars ; Ostapenia, Alexander ; Parparov, Arkady ; [et al.]

Oxford, UK : Blackwell Science Pty

Lakes & reservoirs 8 (2003), S. 0

add to mindlist on the mindlist

Details

ISSN: 1440-1770

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Geography

Notes: The aim of this paper is twofold: to present and discuss practically useful management criteria from different perspectives of lake management (fishery, recreation, conservation, monitoring of water quality and use of water for irrigation and drinking), and to put these criteria into the context of a holistic lake ecosystem model, LakeWeb, which accounts for production, biomasses, predation and abiotic/biotic feedbacks related to nine key functional groups of organisms constituting the lake ecosystem. These are phytoplankton, benthic algae, macrophytes, bacterioplankton, herbivorous zooplankton, predatory zooplankton, zoobenthos, prey fish and predatory fish. The LakeWeb model also includes a mass-balance model for phosphorus and calculates bio-uptake and retention of phosphorus in these groups of organisms. It also includes submodels for the depth of the photic zone and lake temperature. The LakeWeb model is driven by few and readily accessible driving variables and it has been extensively tested and shown to capture fundamental lake foodweb interactions very well, which should lend credibility to the scenarios discussed in this paper regarding the conditions in Lake Batorino, Belarus. The LakeWeb model offers a tool to address important, often very complex, scientific problems in a realistic manner. The first scenario describes the changes after 1990 when there was a drastic reduction in the use of fertilizers in agriculture because of political changes and the corresponding changes in lake characteristics and foodweb structures utilizing the given management criteria. The second scenario describes, for comparative purposes, the probable alterations in the lake foodweb related to global climatic changes; in this case, warming and increased temperature variations. This study indicates that there are several similarities between eutrophication and increases in temperatures, which are discussed in this paper along with the mechanistic reasons related to such changes by using a set of general management criteria.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1046/j.1320-5331.2003.00216.x

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

5

Electronic Resource

Internal loading: A new solution to an old problem in aquatic sciences (2004)

Håkanson, Lars

Oxford, UK : Blackwell Science Pty

Lakes & reservoirs 9 (2004), S. 0

add to mindlist on the mindlist

Details

ISSN: 1440-1770

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Geography

Notes: Internal loading has long been regarded as an ‘Achilles heel’ in aquatic science and management. Internal loading is of fundamental importance in large and shallow lakes, where even low wind velocities can cause a considerable resuspension of matter deposited on the lake bed. The resuspended matter, and the chemical substances bound to the resuspended matter, will influence almost all processes in the aquatic ecosystem, such as water clarity and depth of the photic zone, and hence, primary and secondary production. If the sediments are contaminated, it will increase the concentrations of harmful substances in water and sediments and the potential ecosystem effects related to such concentrations. This paper presents an overview of the processes regulating bottom dynamic conditions in lakes (erosion, transport, accumulation), provides examples on the role of internal loading within the context of limnology and water management, and presents a new, general approach to quantify internal loading from sediments in lakes. The new approach has been critically tested, being a key factor behind the increase in predictive power of a new generation of lake models meant to be used for practical water management. Internal loading of any water pollutant depends on sedimentation. Sedimentation in this approach is presented as a function of two substance-specific variables, including the fall velocity of the carrier-particles and the particulate fraction (which, by definition, is the only fraction of a water pollutant that can settle out on the lake bed), and three generic variables, including mean depth, suspended particulate matter and ET-areas (areas of erosion and transport). On ET-areas there is, by definition, a discontinuous sedimentation of materials that settles according to Stokes' law. Basically, internal loading is the sum of advective (resuspension) and diffusive transport from the sediments. Resuspension from ET-areas is given as a function of the lake form (a new algorithm based on the volume development) and the age of ET-sediments.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1111/j.1440-1770.2004.00230.x

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

6

Electronic Resource

A general management model to optimize lake liming operations (2003)

Håkanson, Lars

Oxford, UK : Blackwell Science Pty

Lakes & reservoirs 8 (2003), S. 0

add to mindlist on the mindlist

Details

ISSN: 1440-1770

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Geography

Notes: One of the most common ways to combat the ecosystem effects of acid rain is liming, which can be performed in many ways, such as lake liming, wetland liming, full-scale drainage area liming, and by dosers in tributaries. This study presents results from extensive liming operations in many Swedish lakes. A practically useful management model for planning and predicting the outcome of liming is presented. The model is based on a validated, general dynamic model for radiocaesium, which has also been used with very good results for radiostrontium, different metals and phosphorus. In this work, the model is applied for calcium from liming. Lake liming can be regarded as a tracer experiment to test the dynamic model. A few of the lakes have been used for the calibrations of the model, and then the model has been validated (blind-tested) using 68 lakes for pH and 17 lakes for calcium concentrations. Results were very good or good in 97% of the cases for pH and 94% of the cases for calcium. Controls in the two lakes where the dynamic model did not give good pH predictions revealed that these two lakes were fertilized and limed a few years before this study started. If those conditions are accounted for, the model would give good results in these cases also. The model also includes submodels to calculate initial pH, and how this is related to catchment area and lake morphometric conditions, as well as target pH and how this is related to initial pH, and the large-scale, long-time influences of deposition of sulphur and other acidifying compounds from the burning of fossil fuels. In order to make the model practically useful, only variables readily accessible from maps and standard monitoring programmes have been accepted as driving variables (such as lake area and mean depth). This work also presents critical model tests (sensitivity and uncertainty analyses using Monte Carlo techniques). These tests have demonstrated that the critical part determining the predictive success of the model is related to the final calculation step where the calculated calcium concentration is transformed into a change in lake pH. It has also been demonstrated that more detailed characterizations of the catchment areas by means of drainage area zonation or Geographical Information System techniques will not increase the predictive accuracy of initial pH values, and that most lakes in the northern part of Sweden were excessively limed to pH values higher, or much higher, than the ‘natural’ or target pH. This is a waste of resources as there are many lakes, especially in the southern part of the country, which need to be limed.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1046/j.1320-5331.2003.00215.x

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

7

Electronic Resource

Assessment of critical loading of lakes as a basis for remedial measures: A review of fundamental concepts (2001)

Håkanson, Lars

Melbourne, Australia : Blackwell Science Asia Pty. Ltd.

Lakes & reservoirs 6 (2001), S. 0

add to mindlist on the mindlist

Details

ISSN: 1440-1770

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Geography

Notes: Lake ecosystems throughout the world are threatened by numerous chemicals. Most people have heard about the major chemical threats to aquatic systems, such as mercury, radionuclides, sulphur and acid rain, and nutrients causing eutrophication effects. How are these threats manifested in ecosystems? What is threatened and why? What can be done for remediation? The complexity of ecosystems has often led to the predictive failure of ecosystems models, and a decade ago these models were rightly regarded with suspicion. At that time, many lake models predicted target variables, such as mean concentrations of toxins in water, sediments and fish, within a factor of 10. There has been very rapid development in predictive modelling for water pollutants during recent years. Today, lake models for water pollutants predict as well as can be measured (i.e. within a factor of 0.25–0.5). One major reason for this rapid development is the Chernobyl accident. Large quantities of radiocaesium were released in a pulse during April–May 1986. In order to follow the radiocaesium along ecosystem pathways, the identification of fundamental transport processes and the structuring of models has been developed. To obtain a high predictive power in ecosystem models, it is crucial to include only the key processes (the optimal size problem). Effect-load- sensitivity (ELS) models play a paramount role in the environmental sciences and lake management. The aim of ELS models is to provide quantitative predictions relating operationally defined ecological effect variables to load and environmental sensitivity variables. Validated ELS models provide a tool to simulate practically feasible remedial measures, and important concepts like critical load, natural load and guideline limits/values can be defined from ELS models. The first objective of this paper is to discuss some basic structures, principles and components of ELS models. Empirical (static) and dynamical (time-dependent) ELS models exist for mercury, radiocaesium and phosphorus in lakes. These models have high predictive powers for a wide range of validation lakes. The second objective of this paper is to demonstrate what can actually be done in water management in terms of remediation of the effects asociated with acidification (lake liming), eutrophication and contamination by mercury and radiocaesium.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1046/j.1440-1770.2001.00124.x

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

8

Electronic Resource

The Derivation and Use of a Dynamic Model for Mercury in Lake Fish Based on a Static (Regression) Model (2000)

Håkanson, Lars

Springer

Water, air & soil pollution 124 (2000), S. 301-317

add to mindlist on the mindlist

Details

ISSN: 1573-2932

Keywords: fish ; lakes ; mercury ; model ; predictions ; regressions ; remedial measures

Source: Springer Online Journal Archives 1860-2000

Topics: Energy, Environment Protection, Nuclear Power Engineering

Notes: Abstract This work presents a new regression model for mercuryin lake fish, which provides the highest r 2-valueso far reported for a predictive model for Hg in lakefish. A new method to transform static regressionmodels to dynamic (time-dependent) models is alsopresented. The method to mathematically transformregression models to dynamic model uses the ecologicalhalflife concept and two differential equations, onefor the target organism (the predator) and one for theprey. This method is generic and can be applied inanalogous cases. The practical use of the dynamicmodel is illustrated in two case studies involvinglake liming and fertilization as methods to reduce Hgin lake fish. The dynamic model is a tool to obtainrealistic expectations of the recovery process, whichis slow because Hg in lake fish has a relatively longecological halflife (about 3 yr).

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1023/A:1005256212158

Permalink