@phdthesis{CalderonQuinonez2023,
  author    = {Calder{\´o}n Qui{\~n}{\´o}nez, Ana Patricia},
  title     = {Ecology and conservation of the jaguar (Panthera onca) in Central America},
  doi       = {10.25932/publishup-61367},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-613671},
  school      = {Universit{\"a}t Potsdam},
  pages     = {140},
  year      = {2023},
  abstract  = {Conservation of the jaguar relies on holistic and transdisciplinary conservation strategies that integratively safeguard essential, connected habitats, sustain viable populations and their genetic exchange, and foster peaceful human-jaguar coexistence. These strategies define four research priorities to advance jaguar conservation throughout the species' range. In this thesis I provide several relevant ecological and sociological insights into these research priorities, each addressed in a separate chapter. I focus on the effects of anthropogenic landscapes on jaguar habitat use and population gene flow, spatial patterns of jaguar habitat suitability and functional population connectivity, and on innovative governance approaches which can work synergistically to help achieve human-wildlife conviviality. Furthermore, I translate these insights into recommendations for conservation practice by providing tools and suggestions that conservation managers and stakeholders can use to implement local actions but also make broad scale conservation decisions in Central America. In Chapter 2, I model regional habitat use of jaguars, producing spatially-explicit maps for management of key areas of habitat suitability. Using an occupancy model of 13-year-camera-trap occurrence data, I show that human influence has the strongest impact on jaguar habitat use, and that Jaguar Conservation Units are the most important reservoirs of high quality habitat in this region. I build upon these results by zooming in to an area of high habitat suitability loss in Chapter 3, northern Central America. Here I study the drivers of jaguar gene flow and I produce spatially-explicit maps for management of key areas of functional population connectivity in this region. I use microsatellite data and pseudo-optimized multiscale, multivariate resistance surfaces of gene flow to show that jaguar gene flow is influenced by environmental, and even more strongly, by human influence variables; and that the areas of lowest gene flow resistance largely coincide with the location of the Jaguar Conservation Units. Given that human activities significantly impact jaguar habitat use and gene flow, securing viable jaguar populations in anthropogenic landscapes also requires fostering peaceful human-wildlife coexistence. This is a complex challenge that cannot be met without transdisciplinary academic research and cross-sectoral, collaborative governance structures that effectively respond to the multiple challenges of such coexistence. With this in mind, I focus in Chapter 4 on carnivore conservation initiatives that apply transformative governance approaches to enact transformative change towards human-carnivore coexistence. Using the frameworks of transformative biodiversity governance and convivial conservation, I highlight in this chapter concrete pathways, supported by more inclusive, democratic forms of conservation decision-making and participation that promote truly transformative changes towards human-jaguar conviviality.},
  language  = {en}
}
@phdthesis{Clodong2004,
  author    = {Clodong, S{\´e}bastien},
  title     = {Recurrent outbreaks in ecology : chaotic dynamics in complex networks},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-0001626},
  school      = {Universit{\"a}t Potsdam},
  year      = {2004},
  abstract  = {Gegenstand der Dissertation ist die Untersuchung von wiederkehrenden Ausbr{\"u}chen (wie z.B. Epidemien) in der Natur. Dies gelang anhand von Modellen, die die Dynamik von Phytoplankton und die Ausbreitung von Krankheiten zwischen St{\"a}dten beschreiben. Diese beide Systeme bilden hervorragende Beispiele f{\"u}r solche Ph{\"a}nomene. Die Frage, ob die in der Zeit wiederkehrenden Ausbr{\"u}che ein Ausdruck chaotischer Dynamik sein k{\"o}nnen, ist aktuell in der {\"O}kologie und fasziniert Wissenschaftler dieser Disziplin. Wir konnten zeigen, dass sich das Plankton-Modell im Falle von periodischem Antreiben {\"u}ber die N{\"a}hrstoffe in einem chaotischen Regime befindet. Diese Dynamik wurde als die komplexe Wechselwirkung zweier Oszillatoren verstanden. Ebenfalls wurde die Ausbreitung von Epidemien in Netzwerken wechselwirkender St{\"a}dte mit unterschiedlichen Gr{\"o}ssen untersucht. Daf{\"u}r wurde zun{\"a}chst die Kopplung zwischen zwei St{\"a}dten als Verh{\"a}ltnis der Stadtgr{\"o}ssen eingef{\"u}hrt. Es konnte gezeigt werden, dass das System sich in einem globalen zweij{\"a}hrigen Zyklus, der auch in den realen Daten beobachtet wird, befinden kann. Der Effekt von Heterogenit{\"a}t in der Gr{\"o}sseverteilung ist durch gewichtete Kopplung von generischen Modellen (Zelt- und Logistische Abbildung) in Netzwerken im Detail untersucht worden. Eine neue Art von Kopplungsfunktion mit nichtlinearer S{\"a}ttigung wurde eingef{\"u}hrt, um die Stabilit{\"a}t des Systems zu gew{\"a}hrleisten. Diese Kopplung beinhaltet einen Parameter, der es erlaubt, die Netzwerktopologie von globaler Kopplung in gerichtete Netzwerke gleichm{\"a}ssig umzuwandeln. Die Dynamik des Systems wurde anhand von Bifurkationsdiagrammen untersucht. Zum Verst{\"a}ndnis dieser Dynamik wurde eine effektive Theorie, die die beobachteten Bifurkationen sehr gut nachahmt, entwickelt.},
  language  = {en}
}
@article{Ette2019,
  author    = {Ette, Ottmar},
  title     = {Faszination AvH},
  series = {HiN : Alexander von Humboldt im Netz ; international review for Humboldtian studies},
  volume    = {XX},
  journal   = {HiN : Alexander von Humboldt im Netz ; international review for Humboldtian studies},
  number    = {38},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {1617-5239},
  doi       = {10.25932/publishup-43469},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-434694},
  pages     = {5 -- 13},
  year      = {2019},
  abstract  = {Alexander von Humboldts Forschungsreise in die Neue Welt ist ein Gr{\"u}ndungsmoment moderner Wissenschaft. Sie liefert uns Impulse und Grundlagen f{\"u}r ein 21. Jahrhundert, das im Zeichen des Zusammendenkens und Zusammenlebens stehen muss. Von der lange versch{\"u}tteten Tradition einer Humboldt'schen Wissenschaft aus lassen sich heute, am Ausgang unserer aktuellen Globalisierungsphase, neue Zuk{\"u}nfte denken und entfalten. Das Zusammendenken von Natur und Kultur im Horizont einer {\"O}kologie, die sich mit Gesellschafts- und Wirtschaftsstrukturen vernetzt; der Entwurf einer Kosmopolitik, die nicht auf Machtasymme­trie, Inferiorisierung und Abh{\"a}ngigkeit abzielt, sondern die Zirkulation von Wissen zur Grundlage einer sich demokratisierenden Weltgesellschaft macht: Dies sind Kreuzungspunkte eines Denkens, das nicht nur an Aktualit{\"a}t, sondern im Zeichen neu entfachter Nationalismen, neuer Fundamentalismen und neuer globaler Ausgrenzungen vor allem an Dringlichkeit gewonnen hat.},
  language  = {de}
}
@article{Grote2021,
  author    = {Grote, Mathias},
  title     = {„Aus dem Kleinen bauen sich die Welten" - Christian Gottfried Ehrenbergs {\"o}kologische Mikrobiologie avant la lettre},
  series = {HiN : Alexander von Humboldt im Netz = Christian Gottfried Ehrenberg},
  volume    = {XXII},
  journal   = {HiN : Alexander von Humboldt im Netz = Christian Gottfried Ehrenberg},
  number    = {42},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {1617-5239},
  doi       = {https://doi.org/10.18443/318},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-515016},
  pages     = {19 -- 32},
  year      = {2021},
  abstract  = {Die Geschichte der Mikrobiologie als Laborwissenschaft des sp{\"a}ten 19. Jahrhunderts hat f{\"u}r Ehrenberg keinen Platz. Unmodern, ja fehlerhaft scheinen die Befunde dieses „Humboldt en miniature", der die Belebtheit von Wasser oder Luft mikroskopisch untersuchte, der Proben aus aller Welt sammelte und so zahlreiche „Infusorien" genannte Mikroben sowie deren Effekte etwa bei Blutwundern beschrieb, deren Beteiligung an Infektionskrankheiten aber verneinte. Zugleich scheint sein {\"o}kologischer Blick auf den Mikrokosmos die Gegenwart auf {\"u}berraschende Weise anzusprechen - einerseits weil Mikroben omnipr{\"a}sentes Faszinosum wie Bedrohung bleiben, andererseits weil viele der Pr{\"a}missen von Pasteur und Koch im Zeitalter der Genomik {\"u}berholt erscheinen. Ausgehend von der zwiesp{\"a}ltigen Position Ehrenbergs fragt dieser Artikel, warum er m{\"o}glicherweise gerade deswegen spannender ist, als ihn die Historiographie bislang hat erscheinen lassen.},
  language  = {de}
}
@phdthesis{Guill2022,
  author    = {Guill, Christian},
  title     = {Structure, stability and functioning of food webs},
  doi       = {10.25932/publishup-56115},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-561153},
  school      = {Universit{\"a}t Potsdam},
  pages     = {250},
  year      = {2022},
  abstract  = {In this thesis, a collection of studies is presented that advance research on complex food webs in several directions. Food webs, as the networks of predator-prey interactions in ecosystems, are responsible for distributing the resources every organism needs to stay alive. They are thus central to our understanding of the mechanisms that support biodiversity, which in the face of increasing severity of anthropogenic global change and accelerated species loss is of highest importance, not least for our own well-being. The studies in the first part of the thesis are concerned with general mechanisms that determine the structure and stability of food webs. It is shown how the allometric scaling of metabolic rates with the species' body masses supports their persistence in size-structured food webs (where predators are larger than their prey), and how this interacts with the adaptive adjustment of foraging efforts by consumer species to create stable food webs with a large number of coexisting species. The importance of the master trait body mass for structuring communities is further exemplified by demonstrating that the specific way the body masses of species engaging in empirically documented predator-prey interactions affect the predator's feeding rate dampens population oscillations, thereby helping both species to survive. In the first part of the thesis it is also shown that in order to understand certain phenomena of population dynamics, it may be necessary to not only take the interactions of a focal species with other species into account, but to also consider the internal structure of the population. This can refer for example to different abundances of age cohorts or developmental stages, or the way individuals of different age or stage interact with other species. Building on these general insights, the second part of the thesis is devoted to exploring the consequences of anthropogenic global change on the persistence of species. It is first shown that warming decreases diversity in size-structured food webs. This is due to starvation of large predators on higher trophic levels, which suffer from a mismatch between their respiration and ingestion rates when temperature increases. In host-parasitoid networks, which are not size-structured, warming does not have these negative effects, but eutrophication destabilises the systems by inducing detrimental population oscillations. In further studies, the effect of habitat change is addressed. On the level of individual patches, increasing isolation of habitat patches has a similar effect as warming, as it leads to decreasing diversity due to the extinction of predators on higher trophic levels. In this case it is caused by dispersal mortality of smaller and therefore less mobile species on lower trophic levels, meaning that an increasing fraction of their biomass production is lost to the inhospitable matrix surrounding the habitat patches as they become more isolated. It is further shown that increasing habitat isolation desynchronises population oscillations between the patches, which in itself helps species to persist by dampening fluctuations on the landscape level. However, this is counteracted by an increasing strength of local population oscillations fuelled by an indirect effect of dispersal mortality on the feeding interactions. Last, a study is presented that introduces a novel mechanism for supporting diversity in metacommunities. It builds on the self-organised formation of spatial biomass patterns in the landscape, which leads to the emergence of spatio-temporally varying selection pressures that keep local communities permanently out of equilibrium and force them to continuously adapt. Because this mechanism relies on the spatial extension of the metacommunity, it is also sensitive to habitat change. In the third part of the thesis, the consequences of biodiversity for the functioning of ecosystems are explored. The studies focus on standing stock biomass, biomass production, and trophic transfer efficiency as ecosystem functions. It is first shown that increasing the diversity of animal communities increases the total rate of intra-guild predation. However, the total biomass stock of the animal communities increases nevertheless, which also increases their exploitative pressure on the underlying plant communities. Despite this, the plant communities can maintain their standing stock biomass due to a shift of the body size spectra of both animal and plant communities towards larger species with a lower specific respiration rate. In another study it is further demonstrated that the generally positive relationship between diversity and the above mentioned ecosystem functions becomes steeper when not only the feeding interactions but also the numerous non-trophic interactions (like predator interference or competition for space) between the species of an ecosystem are taken into account. Finally, two studies are presented that demonstrate the power of functional diversity as explanatory variable. It is interpreted as the range spanned by functional traits of the species that determine their interactions. This approach allows to mechanistically understand how the ecosystem functioning of food webs with multiple trophic levels is affected by all parts of the food web and why a high functional diversity is required for efficient transportation of energy from primary producers to the top predators. The general discussion draws some synthesising conclusions, e.g. on the predictive power of ecosystem functioning to explain diversity, and provides an outlook on future research directions.},
  language  = {en}
}
@phdthesis{Hippel2024,
  author    = {Hippel, Barbara von},
  title     = {Long-term bacteria-fungi-plant associations in permafrost soils inferred from palaeometagenomics},
  doi       = {10.25932/publishup-63600},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-636009},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xii, 198},
  year      = {2024},
  abstract  = {The arctic is warming 2 - 4 times faster than the global average, resulting in a strong feedback on northern ecosystems such as boreal forests, which cover a vast area of the high northern latitudes. With ongoing global warming, the treeline subsequently migrates northwards into tundra areas. The consequences of turning ecosystems are complex: on the one hand, boreal forests are storing large amounts of global terrestrial carbon and act as a carbon sink, dragging carbon dioxide out of the global carbon cycle, suggesting an enhanced carbon uptake with increased tree cover. On the other hand, with the establishment of trees, the albedo effect of tundra decreases, leading to enhanced soil warming. Meanwhile, permafrost thaws, releasing large amounts of previously stored carbon into the atmosphere. So far, mainly vegetation dynamics have been assessed when studying the impact of warming onto ecosystems. Most land plants are living in close symbiosis with bacterial and fungal communities, sustaining their growth in nutrient poor habitats. However, the impact of climate change on these subsoil communities alongside changing vegetation cover remains poorly understood. Therefore, a better understanding of soil community dynamics on multi millennial timescales is inevitable when addressing the development of entire ecosystems. Unravelling long-term cross-kingdom dependencies between plant, fungi, and bacteria is not only a milestone for the assessment of warming on boreal ecosystems. On top, it also is the basis for agriculture strategies to sustain society with sufficient food in a future warming world. The first objective of this thesis was to assess ancient DNA as a proxy for reconstructing the soil microbiome (Manuscripts I, II, III, IV). Research findings across these projects enable a comprehensive new insight into the relationships of soil microorganisms to the surrounding vegetation. First, this was achieved by establishing (Manuscript I) and applying (Manuscript II) a primer pair for the selective amplification of ancient fungal DNA from lake sediment samples with the metabarcoding approach. To assess fungal and plant co-variation, the selected primer combination (ITS67, 5.8S) amplifying the ITS1 region was applied on samples from five boreal and arctic lakes. The obtained data showed that the establishment of fungal communities is impacted by warming as the functional ecological groups are shifting. Yeast and saprotroph dominance during the Late Glacial declined with warming, while the abundance of mycorrhizae and parasites increased with warming. The overall species richness was also alternating. The results were compared to shotgun sequencing data reconstructing fungi and bacteria (Manuscripts III, IV), yielding overall comparable results to the metabarcoding approach. Nonetheless, the comparison also pointed out a bias in the metabarcoding, potentially due to varying ITS lengths or copy numbers per genome. The second objective was to trace fungus-plant interaction changes over time (Manuscripts II, III). To address this, metabarcoding targeting the ITS1 region for fungi and the chloroplast P6 loop for plants for the selective DNA amplification was applied (Manuscript II). Further, shotgun sequencing data was compared to the metabarcoding results (Manuscript III). Overall, the results between the metabarcoding and the shotgun approaches were comparable, though a bias in the metabarcoding was assumed. We demonstrated that fungal shifts were coinciding with changes in the vegetation. Yeast and lichen were mainly dominant during the Late Glacial with tundra vegetation, while warming in the Holocene lead to the expansion of boreal forests with increasing mycorrhizae and parasite abundance. Aside, we highlighted that Pinaceae establishment is dependent on mycorrhizal fungi such as Suillineae, Inocybaceae, or Hyaloscypha species also on long-term scales. The third objective of the thesis was to assess soil community development on a temporal gradient (Manuscripts III, IV). Shotgun sequencing was applied on sediment samples from the northern Siberian lake Lama and the soil microbial community dynamics compared to ecosystem turnover. Alongside, podzolization processes from basaltic bedrock were recovered (Manuscript III). Additionally, the recovered soil microbiome was compared to shotgun data from granite and sandstone catchments (Manuscript IV, Appendix). We assessed if the establishment of the soil microbiome is dependent on the plant taxon and as such comparable between multiple geographic locations or if the community establishment is driven by abiotic soil properties and as such the bedrock area. We showed that the development of soil communities is to a great extent driven by the vegetation changes and temperature variation, while time only plays a minor role. The analyses showed general ecological similarities especially between the granite and basalt locations, while the microbiome on species-level was rather site-specific. A greater number of correlated soil taxa was detected for deep-rooting boreal taxa in comparison to grasses with shallower roots. Additionally, differences between herbaceous taxa of the late Glacial compared to taxa of the Holocene were revealed. With this thesis, I demonstrate the necessity to investigate subsoil community dynamics on millennial time scales as it enables further understanding of long-term ecosystem as well as soil development processes and such plant establishment. Further, I trace long-term processes leading to podzolization which supports the development of applied carbon capture strategies under future global warming.},
  language  = {en}
}
@phdthesis{Kolk2019,
  author    = {Kolk, Jens},
  title     = {The long-term legacy of historical land cover changes},
  doi       = {10.25932/publishup-43939},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-439398},
  school      = {Universit{\"a}t Potsdam},
  pages     = {196},
  year      = {2019},
  abstract  = {Over the last years there is an increasing awareness that historical land cover changes and associated land use legacies may be important drivers for present-day species richness and biodiversity due to time-delayed extinctions or colonizations in response to historical environmental changes. Historically altered habitat patches may therefore exhibit an extinction debt or colonization credit and can be expected to lose or gain species in the future. However, extinction debts and colonization credits are difficult to detect and their actual magnitudes or payments have rarely been quantified because species richness patterns and dynamics are also shaped by recent environmental conditions and recent environmental changes. In this thesis we aimed to determine patterns of herb-layer species richness and recent species richness dynamics of forest herb layer plants and link those patterns and dynamics to historical land cover changes and associated land use legacies. The study was conducted in the Prignitz, NE-Germany, where the forest distribution remained stable for the last ca. 100 years but where a) the deciduous forest area had declined by more than 90 per cent (leaving only remnants of "ancient forests"), b) small new forests had been established on former agricultural land ("post-agricultural forests"). Here, we analyzed the relative importance of land use history and associated historical land cover changes for herb layer species richness compared to recent environmental factors and determined magnitudes of extinction debt and colonization credit and their payment in ancient and post-agricultural forests, respectively. We showed that present-day species richness patterns were still shaped by historical land cover changes that ranged back to more than a century. Although recent environmental conditions were largely comparable we found significantly more forest specialists, species with short-distance dispersal capabilities and clonals in ancient forests than in post-agricultural forests. Those species richness differences were largely contingent to a colonization credit in post-agricultural forests that ranged up to 9 species (average 4.7), while the extinction debt in ancient forests had almost completely been paid. Environmental legacies from historical agricultural land use played a minor role for species richness differences. Instead, patch connectivity was most important. Species richness in ancient forests was still dependent on historical connectivity, indicating a last glimpse of an extinction debt, and the colonization credit was highest in isolated post-agricultural forests. In post-agricultural forests that were better connected or directly adjacent to ancient forest patches the colonization credit was way smaller and we were able to verify a gradual payment of the colonization credit from 2.7 species to 1.5 species over the last six decades.},
  language  = {en}
}
@misc{Langer2011,
  type      = {Master Thesis},
  author    = {Langer, Marco},
  title     = {The effect of native forest dynamics upon the arrangements of species in oak forests-analysis of heterogeneity effects at the example of epigeal arthropods},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-55588},
  school      = {Universit{\"a}t Potsdam},
  year      = {2011},
  abstract  = {The heterogeneity in species assemblages of epigeal spiders was studied in a natural forest and in a managed forest. Additionally the effects of small-scale microhabitat heterogeneity of managed and unmanaged forests were determined by analysing the spider assemblages of three different microhabitat structures (i. vegetation, ii. dead wood. iii. litter cover). The spider were collected in a block design by pitfall traps (n=72) in a 4-week interval. To reveal key environmental factors affecting the spider distribution abiotic and biotic habitat parameters (e.g. vegetation parameters, climate parameters, soil moisture) were assessed around each pitfall trap. A TWINSPAN analyses separated pitfall traps from the natural forest from traps of the managed forest. A subsequent discriminant analyses revealed that the temperature, the visible sky, the plant diversity and the mean diameter at breast height as key discriminant factors between the microhabitat groupings designated by the TWINSPAN analyses. Finally a Redundant analysis (RDA) was done revealing similar environmental factors responsible for the spider species distribution, as a good separation of the different forest types as well as the separation of the microhabitat groupings from the TWINSPAN. Overall the study revealed that the spider communities differed between the forest types as well as between the microhabitat structures and thus species distribution changed within a forest stand on a fine spatial scale. It was documented that the structure of managed forests affects the composition of spider assemblages compared to natural forests significantly and even small scale-heterogeneity seems to influence the spider species composition.},
  language  = {en}
}
@misc{MarkschiesPaesslerGroteetal.2021,
  author    = {Markschies, Christoph and P{\"a}ßler, Ulrich and Grote, Mathias and Greenwood MacKinney, Anne and Kusber, Wolf-Henning and Jahn, Regine and Damaschun, Ferdinand and B{\"o}hme, Katrin},
  title     = {HiN : Alexander von Humboldt im Netz = Christian Gottfried Ehrenberg},
  volume    = {XXII},
  number    = {42},
  editor    = {Ette, Ottmar and Knobloch, Eberhard and P{\"a}ßler, Ulrich},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {2568-3543},
  doi       = {10.25932/publishup-50141},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-501413},
  pages     = {169},
  year      = {2021},
  abstract  = {-Christoph Markschies: Geleitwort -Ulrich P{\"a}ßler: Christian Gottfried Ehrenberg: Lebensbilder eines Naturforschers -Mathias Grote: „Aus dem Kleinen bauen sich die Welten" - Christian Gottfried Ehrenbergs {\"o}kologische Mikrobiologie avant la lettre -Anne Greenwood MacKinney: Die Inszenierung naturforschender Gelehrsamkeit beim Sammeln: Christian Gottfried Ehrenbergs und Wilhelm Hemprichs nordafrikanische Forschungsreise (1820 - 1825) -Ulrich P{\"a}ßler: Reisen im Nahen Osten. Zeichnungen -Ulrich P{\"a}ßler: Christian Gottfried Ehrenberg und die Biogeographie: Die russisch-sibirische Reise mit Alexander von Humboldt (1829) -Ulrich P{\"a}ßler: Russisch-Sibirische Reise. Zeichnungen -Wolf-Henning Kusber, Regine Jahn: Christian Gottfried Ehrenbergs Zeichnungen: Eine fr{\"u}he wissenschaftliche Dokumentation mikroskopischer Organismen -Ferdinand Damaschun: Christian Gottfried Ehrenberg und die Entwicklung der Mikroskop-Technik im 19. Jahrhundert -Ulrich P{\"a}ßler: Die Reise ins Kleinste der Natur. Zeichnungen -Katrin B{\"o}hme: Das große Ganze: Christian Gottfried Ehrenberg und die Gesellschaft Naturforschender Freunde zu Berlin},
  language  = {de}
}
@phdthesis{Martin2013,
  author    = {Martin, Benjamin},
  title     = {Linking individual-based models and dynamic energy budget theory : lessons for ecology and ecotoxicology},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-67001},
  school      = {Universit{\"a}t Potsdam},
  year      = {2013},
  abstract  = {In the context of ecological risk assessment of chemicals, individual-based population models hold great potential to increase the ecological realism of current regulatory risk assessment procedures. However, developing and parameterizing such models is time-consuming and often ad hoc. Using standardized, tested submodels of individual organisms would make individual-based modelling more efficient and coherent. In this thesis, I explored whether Dynamic Energy Budget (DEB) theory is suitable for being used as a standard submodel in individual-based models, both for ecological risk assessment and theoretical population ecology. First, I developed a generic implementation of DEB theory in an individual-based modeling (IBM) context: DEB-IBM. Using the DEB-IBM framework I tested the ability of the DEB theory to predict population-level dynamics from the properties of individuals. We used Daphnia magna as a model species, where data at the individual level was available to parameterize the model, and population-level predictions were compared against independent data from controlled population experiments. We found that DEB theory successfully predicted population growth rates and peak densities of experimental Daphnia populations in multiple experimental settings, but failed to capture the decline phase, when the available food per Daphnia was low. Further assumptions on food-dependent mortality of juveniles were needed to capture the population dynamics after the initial population peak. The resulting model then predicted, without further calibration, characteristic switches between small- and large-amplitude cycles, which have been observed for Daphnia. We conclude that cross-level tests help detecting gaps in current individual-level theories and ultimately will lead to theory development and the establishment of a generic basis for individual-based models and ecology. In addition to theoretical explorations, we tested the potential of DEB theory combined with IBMs to extrapolate effects of chemical stress from the individual to population level. For this we used information at the individual level on the effect of 3,4-dichloroanailine on Daphnia. The individual data suggested direct effects on reproduction but no significant effects on growth. Assuming such direct effects on reproduction, the model was able to accurately predict the population response to increasing concentrations of 3,4-dichloroaniline. We conclude that DEB theory combined with IBMs holds great potential for standardized ecological risk assessment based on ecological models.},
  language  = {en}
}