TY - JOUR
A1 - De Cahsan, Binia
A1 - Nagel, Rebecca
A1 - Schedina, Ina-Maria
A1 - King, James J.
A1 - Bianco, Pier G.
A1 - Tiedemann, Ralph
A1 - Ketmaier, Valerio
T1 - Phylogeography of the European brook lamprey (Lampetra planeri) and the European river lamprey (Lampetra fluviatilis) species pair based on mitochondrial data
JF - Journal of fish biology
N2 - The European river lamprey Lampetra fluviatilis and the European brook lamprey Lampetra planeri (Block 1784) are classified as a paired species, characterized by notably different life histories but morphological similarities. Previous work has further shown limited genetic differentiation between these two species at the mitochondrial DNA level. Here, we expand on this previous work, which focused on lamprey species from the Iberian Peninsula in the south and mainland Europe in the north, by sequencing three mitochondrial marker regions of Lampetra individuals from five river systems in Ireland and five in southern Italy. Our results corroborate the previously identified pattern of genetic diversity for the species pair. We also show significant genetic differentiation between Irish and mainland European lamprey populations, suggesting another ichthyogeographic district distinct from those previously defined. Finally, our results stress the importance of southern Italian L. planeri populations, which maintain several private alleles and notable genetic diversity.
KW - European lamprey
KW - Lampetra
KW - paired species
KW - phylogeography
KW - population
KW - structure
Y1 - 2020
U6 - https://doi.org/10.1111/jfb.14279
SN - 0022-1112
SN - 1095-8649
VL - 96
IS - 4
SP - 905
EP - 912
PB - Wiley-Blackwell
CY - Oxford [u.a.]
ER -
TY - THES
A1 - Bolius, Sarah
T1 - Microbial invasions in aquatic systems – strain identity, genetic diversity and timing
N2 - Biological invasions are the dispersal and following establishment of species outside their native habitat. Due to globalisation, connectivity of regions and climate changes the number of invasive species and their successful establishment is rising. The impact of these species is mostly negative, can induce community and habitat alterations, and is one main cause for biodiversity loss. This impact is particularly high and less researched in aquatic systems and microbial organisms and despite the high impact, the knowledge about overall mechanisms and specific factors affecting invasions are not fully understood. In general, the characteristics of the habitat, native community and invader determine the invasiveness.
In this thesis, I aimed to provide a better understanding of aquatic invasions focusing on the invader and its traits and identity. This thesis used a set of 12 strains of the invasive cyanobacterium Cylindrospermopsis raciborskii to examine the effect and impact of the invaders’ identity and genetic diversity. Further, the effect of timing on the invasion potential and success was determined, because aquatic systems in particular undergo seasonal fluctuations.
Most studies revealed a higher invasion success with increasing genetic diversity. Here, the increase of the genetic diversity, by either strain richness or phylogenetic dissimilarity, is not firstly driving the invasion, but the strain-identity. The high variability among the strains in traits important for invasions led to the highly varying strain-specific invasion success. This success was most dependent on nitrogen uptake and efficient resource use. The lower invasion success into communities comprising further N-fixing species indicates C. raciborskii can use this advantage only without the presence of competitive species. The relief of grazing pressure, which is suggested to be more important in aquatic invasions, was only promoting the invasion when unselective and larger consumers were present. High abundances of unselective consumers hampered the invasion success.
This indicates a more complex and temporal interplay of competitive and consumptive resistance mechanisms during the invasion process. Further, the fluctuation abundance and presence of competitors (= primary producers) and consumers (= zooplankton) in lakes can open certain ‘invasion windows’.
Remarkably, the composition of the resident community was also strain-specific affected and altered, independent of a high or low invasion success. Prior, this was only documented on the species level. Further, investigations on the population of invasive strains can reveal more about the invasion patterns and how multiple strain invasions change resident communities.
The present dissertation emphasises the importance of invader-addition experiments with a community context and the importance of the strain-level for microbial invasions and in general, e.g. for community assemblies and the outcome of experiments. The strain-specific community changes, also after days, may explain some sudden changes in communities, which have not been explained yet. This and further knowledge may also facilitate earlier and less cost-intensive management to step in, because these species are rarely tracked until they reach a high abundance or bloom, because of their small size.
Concluded for C. raciborskii, it shows that this species is no ‘generalistic’ invader and its invasion success depends more on the competitor presence than grazing pressure. This may explain its, still unknown, invasion pattern, as C. raciborskii is not found in all lakes of a region.
N2 - Biologische Invasionen beschreiben die Ausbreitung und Etablierung von Arten außerhalb ihres natürlichen Verbreitungsgebiets. Das Eindringen dieser invasiven Arten in ein neues Ökosystem hat meist negative Auswirkungen. Beispiele sind unter anderem veränderte Ökosystemprozesse, Lebensräume und Zusammensetzungen der einheimischen Arten, die zu einem Verlust der biologischen Vielfalt führen. Durch die fortschreitende Globalisierung und den Klimawandel steigt die Anzahl invasiver Arten weltweit. Um dies möglichst zu verhindern, müssen die zugrundeliegenden Mechanismen und Faktoren verstanden sein. Besonders bei aquatischen Mikroorganismen ist die Wissenslücke dabei groß und umso drängender, da diese Arten ein hohes Invasionspotential und potentiell stärkere negative Auswirkungen haben.
Die vorliegende Dissertation untersuchte anhand der invasiven Cyanobakterie Cylindrospermopsis raciborskii, den anfänglichen Invasionsprozess, unter besonderer Berücksichtigung der Stamm-Identität, der genetischen Diversität und des Zeitpunkts der Invasion.
Die meisten Studien zu Invasionen zeigen einen positiven Effekt der genetischen Diversität auf Invasionen. Diese Arbeit konnte zeigen, dass der Invasionserfolg auf bestimmte Stamm-spezifische Eigenschaften zurückzuführen ist. Für C. raciborskii war dies eine erhöhte Aufnahme von Stickstoff und eine effizientere Nutzung von Ressourcen. Wie einige andere aquatischen Arten hat C. raciborskii die Fähigkeit über differenzierte Zellen Stickstoff aus der Luft zu fixieren. Des Weiteren fördern bestimmte Umweltbedingungen, wie eine niedrige Nährstoffkonzentration, das Wachstum von C. raciborskii.
Fraßdruck wirkte sich nur negativ aus, wenn unselektive Prädatoren anwesend waren. Zudem zeigten weitere Versuche, dass ihr Konkurrenzvorteil nur in Gemeinschaften ohne weitere Stickstoff-Fixierer und in Stickstoff-reduzierten Habitaten die Etablierung positiv beeinflusst.
Diese Erkenntnisse lassen darauf schließen, dass diverse Eigenschaften und eine zeitliche Abfolge dieser, den Invasionserfolg beeinflussen. Dieser kann einerseits durch den Widerstand der heimischen Arten-Gemeinschaft und zum anderem durch die herrschenden abiotischen Bedingungen verhindert werden. Gerade aquatische Systeme unterlaufen saisonalen Schwankungen und diese erlauben somit bestimmte, temporäre Invasionsmöglichkeiten. Zusätzlich führte die Stamm-Identität zu Änderungen in der einheimischen Artenzusammensetzung, unabhängig vom Erfolg der Invasion - dies wurde bis jetzt nur Art-spezifisch gezeigt.
Damit betont die vorliegende Arbeit die Bedeutung von Stamm-Identitäten auf Invasionen und deren Auswirkungen auf ökologische Prozesse und den Ausgang von Experimenten. Zusammengefasst für C. raciborskii zeigt die Arbeit, dass diese Art keine ‚generell‘ erfolgreiche invasive Art ist und dass der Invasionserfolg eher von den vorhanden konkurrierenden Arten abhängt. Dies könnte das noch unklare Ausbreitungs-Muster erklären.
KW - invasion
KW - cyanobacteria
KW - population
KW - Cylindrospermopsis raciborskii
Y1 - 2018
ER -
TY - GEN
A1 - Siska, Veronika
A1 - Jones, Eppie Ruth
A1 - Jeon, Sungwon
A1 - Bhak, Youngjune
A1 - Kim, Hak-Min
A1 - Cho, Yun Sung
A1 - Kim, Hyunho
A1 - Lee, Kyusang
A1 - Veselovskaya, Elizaveta
A1 - Balueva, Tatiana
A1 - Gallego-Llorente, Marcos
A1 - Hofreiter, Michael
A1 - Bradley, Daniel G.
A1 - Eriksson, Anders
A1 - Pinhasi, Ron
A1 - Bhak, Jong
A1 - Manica, Andrea
T1 - Genome-wide data from two early Neolithic East Asian individuals dating to 7700 years ago
T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2 - Ancient genomes have revolutionized our understanding of Holocene prehistory and, particularly, the Neolithic transition in western Eurasia. In contrast, East Asia has so far received little attention, despite representing a core region at which the Neolithic transition took place independently similar to 3 millennia after its onset in the Near East. We report genome-wide data from two hunter-gatherers from Devil's Gate, an early Neolithic cave site (dated to similar to 7.7 thousand years ago) located in East Asia, on the border between Russia and Korea. Both of these individuals are genetically most similar to geographically close modern populations from the Amur Basin, all speaking Tungusic languages, and, in particular, to the Ulchi. The similarity to nearby modern populations and the low levels of additional genetic material in the Ulchi imply a high level of genetic continuity in this region during the Holocene, a pattern that markedly contrasts with that reported for Europe.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 791
KW - Mitochondrial-DNA analysis
KW - positive selection
KW - jomon skeletons
KW - ancient DNA
KW - pigmentation
KW - population
KW - admixture
KW - edar
KW - gene
KW - polymorohism
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-439977
SN - 1866-8372
IS - 791
ER -
TY - GEN
A1 - Baylis, Alastair M. M.
A1 - Kowalski, Gabriele Joanna
A1 - Voigt, Christian C.
A1 - Orben, Rachael A.
A1 - Trillmich, Fritz
A1 - Staniland, Iain J.
A1 - Hoffman, Joseph I.
T1 - Pup vibrissae stable isotopes reveal geographic differences in adult female southern sea lion habitat use during gestation
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Individuals within populations often differ substantially in habitat use, the ecological consequences of which can be far reaching. Stable isotope analysis provides a convenient and often cost effective means of indirectly assessing the habitat use of individuals that can yield valuable insights into the spatiotemporal distribution of foraging specialisations within a population. Here we use the stable isotope ratios of southern sea lion (Otaria flavescens) pup vibrissae at the Falkland Islands, in the South Atlantic, as a proxy for adult female habitat use during gestation. A previous study found that adult females from one breeding colony (Big Shag Island) foraged in two discrete habitats, inshore (coastal) or offshore (outer Patagonian Shelf). However, as this species breeds at over 70 sites around the Falkland Islands, it is unclear if this pattern is representative of the Falkland Islands as a whole. In order to characterize habitat use, we therefore assayed carbon (delta C-13) and nitrogen (delta N-15) ratios from 65 southern sea lion pup vibrissae, sampled across 19 breeding colonies at the Falkland Islands. Model-based clustering of pup isotope ratios identified three distinct clusters, representing adult females that foraged inshore, offshore, and a cluster best described as intermediate. A significant difference was found in the use of inshore and offshore habitats between West and East Falkland and between the two colonies with the largest sample sizes, both of which are located in East Falkland. However, habitat use was unrelated to the proximity of breeding colonies to the Patagonian Shelf, a region associated with enhanced biological productivity. Our study thus points towards other factors, such as local oceanography and its influence on resource distribution, playing a prominent role in inshore and offshore habitat use.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 546
KW - Falkland islands
KW - Patagonian Shelf
KW - marine predator
KW - ecology
KW - specialization
KW - population
KW - patterns
KW - otters
KW - diet
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-411842
SN - 1866-8372
IS - 546
ER -
TY - JOUR
A1 - Ludwig, Arne
A1 - Reissmann, Monika
A1 - Benecke, Norbert
A1 - Bellone, Rebecca
A1 - Sandoval-Castellanos, Edson
A1 - Cieslak, Michael
A1 - González-Fortes, Gloria M.
A1 - Morales-Muniz, Arturo
A1 - Hofreiter, Michael
A1 - Pruvost, Melanie
T1 - Twenty-five thousand years of fluctuating selection on leopard complex spotting and congenital night blindness in horses
JF - Philosophical transactions of the Royal Society of London : B, Biological sciences
N2 - Leopard complex spotting is inherited by the incompletely dominant locus, LP, which also causes congenital stationary night blindness in homozygous horses. We investigated an associated single nucleotide polymorphism in the TRPM1 gene in 96 archaeological bones from 31 localities from Late Pleistocene (approx. 17 000 YBP) to medieval times. The first genetic evidence of LP spotting in Europe dates back to the Pleistocene. We tested for temporal changes in the LP associated allele frequency and estimated coefficients of selection by means of approximate Bayesian computation analyses. Our results show that at least some of the observed frequency changes are congruent with shifts in artificial selection pressure for the leopard complex spotting phenotype. In early domestic horses from Kirklareli-Kanligecit (Turkey) dating to 2700-2200 BC, a remarkably high number of leopard spotted horses (six of 10 individuals) was detected including one adult homozygote. However, LP seems to have largely disappeared during the late Bronze Age, suggesting selection against this phenotype in early domestic horses. During the Iron Age, LP reappeared, probably by reintroduction into the domestic gene pool from wild animals. This picture of alternating selective regimes might explain how genetic diversity was maintained in domestic animals despite selection for specific traits at different times.
KW - ancient DNA
KW - coat colour
KW - domestication
KW - Equus
KW - palaeogenetics
KW - population
Y1 - 2015
U6 - https://doi.org/10.1098/rstb.2013.0386
SN - 0962-8436
SN - 1471-2970
VL - 370
IS - 1660
PB - Royal Society
CY - London
ER -
TY - GEN
A1 - Wilske, Burkhard
A1 - Eccard, Jana
A1 - Zistl-Schlingmann, Marcus
A1 - Hohmann, Maximilian
A1 - Methler, Annabel
A1 - Herde, Antje
A1 - Liesenjohann, Thilo
A1 - Dannenmann, Michael
A1 - Butterbach-Bahl, Klaus
A1 - Breuer, Lutz
T1 - Effects of short term bioturbation by common voles on biogeochemical soil variables
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Bioturbation contributes to soil formation and ecosystem functioning. With respect to the active transport of matter by voles, bioturbation may be considered as a very dynamic process among those shaping soil formation and biogeochemistry. The present study aimed at characterizing and quantifying the effects of bioturbation by voles on soil water relations and carbon and nitrogen stocks. Bioturbation effects were examined based on a field set up in a luvic arenosol comprising of eight 50 x 50 m enclosures with greatly different numbers of common vole (Microtus arvalis L., ca. 35-150 individuals ha(-1) mth(-1)). Eleven key soil variables were analyzed: bulk density, infiltration rate, saturated hydraulic conductivity, water holding capacity, contents of soil organic carbon (SOC) and total nitrogen (N), CO2 emission potential, C/N ratio, the stable isotopic signatures of C-13 and N-15, and pH. The highest vole densities were hypothesized to cause significant changes in some variables within 21 months. Results showed that land history had still a major influence, as eight key variables displayed an additional or sole influence of topography. However, the delta N-15 at depths of 10-20 and 20-30 cm decreased and increased with increasing vole numbers, respectively. Also the CO2 emission potential from soil collected at a depth of 15-30 cm decreased and the C/N ratio at 5-10 cm depth narrowed with increasing vole numbers. These variables indicated the first influence of voles on the respective mineralization processes in some soil layers. Tendencies of vole activity homogenizing SOC and N contents across layers were not significant. The results of the other seven key variables did not confirm significant effects of voles. Thus overall, we found mainly a first response of variables that are indicative for changes in biogeochemical dynamics but not yet of those representing changes in pools.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 499
KW - small mammalian herbivores
KW - Microtus agrestis
KW - pocket gophers
KW - field voles
KW - ecosystem services
KW - functional traits
KW - organic-carbon
KW - nitrogen
KW - population
KW - landscape
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-408375
SN - 1866-8372
IS - 499
ER -
TY - GEN
A1 - Mooij, Wolf M.
A1 - Trolle, Dennis
A1 - Jeppesen, Erik
A1 - Arhonditsis, George B.
A1 - Belolipetsky, Pavel V.
A1 - Chitamwebwa, Deonatus B. R.
A1 - Degermendzhy, Andrey G.
A1 - DeAngelis, Donald L.
A1 - Domis, Lisette Nicole de Senerpont
A1 - Downing, Andrea S.
A1 - Elliott, J. Alex
A1 - Fragoso Jr., Carlos Ruberto
A1 - Gaedke, Ursula
A1 - Genova, Svetlana N.
A1 - Gulati, Ramesh D.
A1 - Håkanson, Lars
A1 - Hamilton, David P.
A1 - Hipsey, Matthew R.
A1 - ‘t Hoen, Jochem
A1 - Hülsmann, Stephan
A1 - Los, F. Hans
A1 - Makler-Pick, Vardit
A1 - Petzoldt, Thomas
A1 - Prokopkin, Igor G.
A1 - Rinke, Karsten
A1 - Schep, Sebastiaan A.
A1 - Tominaga, Koji
A1 - Van Dam, Anne A.
A1 - Van Nes, Egbert H.
A1 - Wells, Scott A.
A1 - Janse, Jan H.
T1 - Challenges and opportunities for integrating lake ecosystem modelling approaches
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - A large number and wide variety of lake ecosystem models have been developed and published during the past four decades. We identify two challenges for making further progress in this field. One such challenge is to avoid developing more models largely following the concept of others ('reinventing the wheel'). The other challenge is to avoid focusing on only one type of model, while ignoring new and diverse approaches that have become available ('having tunnel vision'). In this paper, we aim at improving the awareness of existing models and knowledge of concurrent approaches in lake ecosystem modelling, without covering all possible model tools and avenues. First, we present a broad variety of modelling approaches. To illustrate these approaches, we give brief descriptions of rather arbitrarily selected sets of specific models. We deal with static models (steady state and regression models), complex dynamic models (CAEDYM, CE-QUAL-W2, Delft 3D-ECO, LakeMab, LakeWeb, MyLake, PCLake, PROTECH, SALMO), structurally dynamic models and minimal dynamic models. We also discuss a group of approaches that could all be classified as individual based: super-individual models (Piscator, Charisma), physiologically structured models, stage-structured models and traitbased models. We briefly mention genetic algorithms, neural networks, Kalman filters and fuzzy logic. Thereafter, we zoom in, as an in-depth example, on the multi-decadal development and application of the lake ecosystem model PCLake and related models (PCLake Metamodel, Lake Shira Model, IPH-TRIM3D-PCLake). In the discussion, we argue that while the historical development of each approach and model is understandable given its 'leading principle', there are many opportunities for combining approaches. We take the point of view that a single 'right' approach does not exist and should not be strived for. Instead, multiple modelling approaches, applied concurrently to a given problem, can help develop an integrative view on the functioning of lake ecosystems. We end with a set of specific recommendations that may be of help in the further development of lake ecosystem models.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1326
KW - aquatic
KW - food web dynamics
KW - plankton
KW - nutrients
KW - spatial
KW - lake
KW - freshwater
KW - marine
KW - community
KW - population
KW - hydrology
KW - eutrophication
KW - global change
KW - climate warming
KW - fisheries
KW - biodiversity
KW - management
KW - mitigation
KW - adaptive processes
KW - non-linear dynamics
KW - analysis
KW - bifurcation
KW - understanding
KW - prediction
KW - model limitations
KW - model integration
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-429839
SN - 1866-8372
IS - 1326
ER -
TY - JOUR
A1 - Mooij, Wolf M.
A1 - Trolle, Dennis
A1 - Jeppesen, Erik
A1 - Arhonditsis, George B.
A1 - Belolipetsky, Pavel V.
A1 - Chitamwebwa, Deonatus B. R.
A1 - Degermendzhy, Andrey G.
A1 - DeAngelis, Donald L.
A1 - Domis, Lisette Nicole de Senerpont
A1 - Downing, Andrea S.
A1 - Elliott, J. Alex
A1 - Fragoso Jr, Carlos Ruberto
A1 - Gaedke, Ursula
A1 - Genova, Svetlana N.
A1 - Gulati, Ramesh D.
A1 - Håkanson, Lars
A1 - Hamilton, David P.
A1 - Hipsey, Matthew R.
A1 - ‘t Hoen, Jochem
A1 - Hülsmann, Stephan
A1 - Los, F. Hans
A1 - Makler-Pick, Vardit
A1 - Petzoldt, Thomas
A1 - Prokopkin, Igor G.
A1 - Rinke, Karsten
A1 - Schep, Sebastiaan A.
A1 - Tominaga, Koji
A1 - Van Dam, Anne A.
A1 - Van Nes, Egbert H.
A1 - Wells, Scott A.
A1 - Janse, Jan H.
T1 - Challenges and opportunities for integrating lake ecosystem modelling approaches
JF - Aquatic ecology
N2 - A large number and wide variety of lake ecosystem models have been developed and published during the past four decades. We identify two challenges for making further progress in this field. One such challenge is to avoid developing more models largely following the concept of others ('reinventing the wheel'). The other challenge is to avoid focusing on only one type of model, while ignoring new and diverse approaches that have become available ('having tunnel vision'). In this paper, we aim at improving the awareness of existing models and knowledge of concurrent approaches in lake ecosystem modelling, without covering all possible model tools and avenues. First, we present a broad variety of modelling approaches. To illustrate these approaches, we give brief descriptions of rather arbitrarily selected sets of specific models. We deal with static models (steady state and regression models), complex dynamic models (CAEDYM, CE-QUAL-W2, Delft 3D-ECO, LakeMab, LakeWeb, MyLake, PCLake, PROTECH, SALMO), structurally dynamic models and minimal dynamic models. We also discuss a group of approaches that could all be classified as individual based: super-individual models (Piscator, Charisma), physiologically structured models, stage-structured models and traitbased models. We briefly mention genetic algorithms, neural networks, Kalman filters and fuzzy logic. Thereafter, we zoom in, as an in-depth example, on the multi-decadal development and application of the lake ecosystem model PCLake and related models (PCLake Metamodel, Lake Shira Model, IPH-TRIM3D-PCLake). In the discussion, we argue that while the historical development of each approach and model is understandable given its 'leading principle', there are many opportunities for combining approaches. We take the point of view that a single 'right' approach does not exist and should not be strived for. Instead, multiple modelling approaches, applied concurrently to a given problem, can help develop an integrative view on the functioning of lake ecosystems. We end with a set of specific recommendations that may be of help in the further development of lake ecosystem models.
KW - aquatic
KW - food web dynamics
KW - plankton
KW - nutrients
KW - spatial
KW - lake
KW - freshwater
KW - marine
KW - community
KW - population
KW - hydrology
KW - eutrophication
KW - global change
KW - climate warming
KW - fisheries
KW - biodiversity
KW - management
KW - mitigation
KW - adaptive processes
KW - non-linear dynamics
KW - analysis
KW - bifurcation
KW - understanding
KW - prediction
KW - model limitations
KW - model integration
Y1 - 2010
U6 - https://doi.org/10.1007/s10452-010-9339-3
SN - 1573-5125
SN - 1386-2588
VL - 44
SP - 633
EP - 667
PB - Springer Science + Business Media B.V.
CY - Dordrecht
ER -
TY - THES
A1 - Svirejeva-Hopkins, Anastasia
T1 - Urbanised territories as a specific component of the global carbon cycle
N2 - Wir betrachten folgende Teile: die zusätzlichen Kohlenstoff(C)-emissionen, welche aus der Umwandlung von natürlichem Umland durch Stadtwachstum resultieren, und die Änderung des C-Flusses durch 'urbanisierte' Ökosysteme, soweit atmosphärisches C durch diese in umliegende natürliche Ökosysteme entlang der Kette “Atmosphäre -> Vegetation -> abgestorbene organische Substanzen” gepumpt wird: d.h. C-Export; für den Zeitraum von 1980 bis 2050. Als Szenario nutzen wir Prognosen der regionalen Stadtbevölkerung, welche durch ein 'Hybridmodell' generiert werden für acht Regionen. Alle Schätzungen der C-Flüsse basieren auf zwei Modellen: das Regression Modell und das sogenannte G-Modell. Die Siedlungsfläche, welche mit dem Wachstum der Stadtbevölkerung zunimmt, wird in 'Grünflächen' (Parks, usw.), Gebäudeflächen und informell städtisch genutzte Flächen (Slums, illegale Lagerplätze, usw.) unterteilt. Es werden jährlich die regionale und globale Dynamik der C-Emissionen und des C-Exports sowie die C-Gesamtbilanz berechnet. Dabei liefern beide Modelle qualitativ ähnliche Ergebnisse, jedoch gibt es einige quantitative Unterschiede. Im ersten Modell erreicht die globale Jahresemission für die Dekade 2020-2030 resultierend aus der Landnutzungsänderung ein Maximum von 205 Mt/a. Die maximalen Beiträge zur globalen Emission werden durch China, die asiatische und die pazifische Region erbracht. Im zweiten Modell erhöht sich die jährliche globale Emission von 1.12 GtC/a für 1980 auf 1.25 GtC/a für 2005 (1Gt = 109 t). Danach beginnt eine Reduzierung. Vergleichen wir das Emissionmaximum mit der Emission durch Abholzung im Jahre 1980 (1.36 GtC/a), können wir konstatieren, daß die Urbanisierung damit in vergleichbarer Grösse zur Emission beiträgt. Bezogen auf die globale Dynamik des jährlichen C-Exports durch Urbanisierung beobachten wir ein monotones Wachstum bis zum nahezu dreifachen Wert von 24 MtC/a für 1980 auf 66 MtC/a für 2050 im ersten Modell, bzw. im zweiten Modell von 249 MtC/a für 1980 auf 505 MtC/a für 2050. Damit ist im zweiten Fall die Transportleistung der Siedlungsgebiete mit dem C-Transport durch Flüsse in die Ozeane (196 .. 537 MtC/a) vergleichbar. Bei der Abschätzung der Gesamtbilanz finden wir, daß die Urbanisierung die Bilanz in Richtung zu einer 'Senke' verschiebt. Entsprechend dem zweiten Modell beginnt sich die C-Gesamtbilanz (nach annähernder Konstanz) ab dem Jahre 2000 mit einer fast konstanten Rate zu verringern. Wenn das Maximum im Jahre 2000 bei 905MtC/a liegt, fällt dieser Wert anschliessend bis zum Jahre 2050 auf 118 MtC/a. Bei Extrapolation dieser Dynamik in die Zukunft können wir annehmen, daß am Ende des 21. Jahrhunderts die “urbane” C-Gesamtbilanz Null bzw. negative Werte erreicht.
N2 - We calculate the additional carbon emissions as a result of the conversion of natural land in a process of urbanisation; and the change of carbon flows by “urbanised” ecosystems, when the atmospheric carbon is exported to the neighboring territories, from 1980 till 2050 for the eight regions of the world. As a scenario we use combined UN and demographic model′s prognoses for regional total and urban population growth. The calculations of urban areas dynamics are based on two models: the regression model and the Gamma-model. The urbanised area is sub-divided on built-up, „green“ (parks, etc.) and informal settlements (favelas) areas. The next step is to calculate the regional and world dynamics of carbon emission and export, and the annual total carbon balance. Both models give similar results with some quantitative differences. In the first model, the world annual emissions attain a maximum of 205 MtC/year between 2020-2030. Emissions will then slowly decrease. The maximum contributions are given by China and the Asia and Pacific regions. In the second model, world annual emissions increase to 1.25 GtC in 2005, beginning to decrease afterwards. If we compare the emission maximum with the annual emission caused by deforestation, 1.36GtC per year, then we can say that the role of urbanised territories (UT) is of a comparable magnitude. Regarding the world annual export of carbon by UT, we observe its monotonous growth by three times, from 24 MtC to 66 MtC in the first model, and from 249 MtC to 505 MtC in the second one. The latter, is therefore comparable to the amount of carbon transported by rivers into the ocean (196-537 MtC). By estimating the total balance we find that urbanisation shifts the total balance towards a “sink” state. The urbanisation is inhibited in the interval 2020-2030, and by 2050 the growth of urbanised areas would almost stop. Hence, the total emission of natural carbon at that stage will stabilise at the level of the 1980s (80 MtC per year). As estimated by the second model, the total balance, being almost constant until 2000, then starts to decrease at an almost constant rate. We can say that by the end of the XXI century, the total carbon balance will be equal to zero, when the exchange flows are fully balanced, and may even be negative, when the system begins to take up carbon from the atmosphere, i.e., becomes a “sink”.
T2 - Urbanised territories as a specific component of the global carbon cycle
KW - Urbanisierung
KW - C-Senke
KW - Bilanz
KW - Kohlenstoffzyklus
KW - Städte
KW - C-Fluss
KW - Slums
KW - Vegetation
KW - Verteilung
KW - urban
KW - land conversion
KW - carbon
KW - sink
KW - cities
KW - urbanisation
KW - emissions
KW - favela
KW - regional
KW - population
KW - density
KW - distribution
KW - flux
KW - vegetation
Y1 - 2004
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-0001512
ER -