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Michael Kröncke

Curriculum Vitae

since 2024  Doctoral thesis in the project “Do annual plants escape root economy? Root functional characteristics in the annual model grass Brachypodium hybridum under increasing drought conditions”

2022-2024 Teaching position at University of Hildesheim in the working group Plant Ecology & Nature Conservation (Prof. Dr. Johannes Metz)

2015 - 2022 Research assistant at the Institute for Environmental Planning at the University of Hanover in the Vegetation Management Working Group (Prof. Dr. Rüdiger Prasse). Teaching in the field of plant ecology (lectures, identification exercises, project work, supervision of internships, supervision of theses, collaboration on research projects, writing research proposals, self-administration).

2011 - 2014 Master's degree in “International Technical and Applied Biology” with a focus on plant ecology under Prof. Dr. Dietmar Zacharias at Bremen University of Applied Sciences. Master's thesis: “The effects of flowering phenology of Empetrum hermaphroditum on gene flow between subpopulations along snow cover gradients.”

2010 - 2011 Year abroad in Recife, Brazil. One semester studying ecology at UFPE Recife. Six-month internship in the vegetation ecology lab (Prof. Dr. Marcelo Tabarelli).

2008 - 2011 Bachelor's degree in “International Technical and Applied Biology” with a focus on plant ecology under Prof. Dr. Dietmar Zacharias at Bremen University of Applied Sciences. Bachelor's thesis: “Boreal Forests: Vegetation and Climate Relevance”

publications

Bienau, Miriam J.; Hattermann, Dirk, Kröncke, Michael; Kretz, Lena; Otte, Annette; Eiserhardt, Wolf L.; Milbau, Ann; Graae, Bente J.; Durka, Walter & Eckstein, R. Lutz (2015): Spross-Morphologie, Blüh-Phänologie und lokale Adaptation bei Empetrum hermaphroditum, einer Schlüsselart boreal-arktischer Ökosysteme, entlang eines Schneedeckungsgradienten. In: Ute Feit & Horst Korn (Hrsg.): Treffpunkt Biologische Vielfalt XIV. Interdisziplinärer Forschungsaustausch im Rahmen des Übereinkommens über die biologische Vielfalt. BfN-Skripten 397, 107-112. https://www.bfn.de/publikationen/bfn-schriften/bfn-schriften-397-treffpunkt-biologische-vielfalt-xiv

Bienau, Miriam J.; Kröncke, Michael; Eiserhardt, Wolf L.; Otte, Annette; Graae, Bente J.; Hagen, Dagmar; Milbau, Ann; Durka, Walter & Eckstein, R. Lutz (2015): Synchronous flowering despite differences in snowmelt timing among habitats of Empetrum hermaphroditum. - Acta Oecologia 69 DOI: 10.1016/j.actao.2015.10.005

Bienau, M. J., Hattermann, D., Kröncke, M., Kretz, L., Otte, A., Eiserhardt, W. L., Milbau, A., Graae, B. J., Durka, W. & Eckstein, R. L. (2014): Snow cover consistently affects growth and reproduction of Empetrum hermaphroditum across latitudinal and local climatic gradients. – Alpine Botany 124 (2) DOI: 10.1007/s00035-014-0137-8

ResearchGate

memberships

  • OIKOS Nordic Society (NSO)
  • International Society for Root Research (ISRR)
  • Naturhistorische Gesellschaft Hannover (NGH)
  • Naturwissenschaftlicher Verein zu Bremen (NWV)
  • Gesellschaft zur Erforschung der Flora Deutschlands (GEFD)
  • Floristisch-Soziologische Arbeitsgemeinschaft (FlorSoz)
  • Gesellschaft für Ökologie (GfÖ)
  • Maker For Humanity (M4H)

 

Research interests

I am interested in how plant species adapt to extreme environments, e.g., in arctic-alpine ecosystems above the tree line, in cities heavily influenced by humans, or in deserts characterized by drought. I find it particularly interesting how plants respond phenologically to changing environmental conditions, such as snowmelt in the mountains or changes in the natural light regime caused by humans (light and temperature are two key factors influencing the timing of the life cycle). It is exciting to see how evolution occurs within species, e.g., spatially along gradients or through geographical isolation (individual mountain peaks as “sky islands,” mosaic structure of the landscape, and the possibility of gene flow between individuals, e.g., rare and endangered plant species), as well as over time (how fast does evolution occur?). Climate change and human activity are challenging plants to adapt quickly to spatial and temporal changes in the environment and will exacerbate extreme conditions in the future. I am also fascinated by exploring the diversity of life forms and landscapes and hope to contribute to a better understanding of the effects of climate change on plants and to taking measures to protect them. Here are a few impressions from the past:

Habitus of Empetrum hermaphroditum (Ericaceae), a key species in Arctic-Alpine ecosystems. The study investigated whether morphology and phenology differ in snow valleys, on wind-swept hilltops, and below the tree line in birch forests (result: morphology does, phenology does not, therefore gene flow between habitats through simultaneous flowering is possible: lower possibility of local adaptation).
Various individuals from these habitats were measured morphometrically: number of leaves (living/dead), specific leaf area (SLA), average leaf weight, length of annual shoot growth, dry weight, etc. This shoot derived from a snow valley with long snow cover, protecting it from cold temperatures during the long winter.
In comparison: The smaller size of the shoots originating from the wind-swept hilltops is clearly visible. On these hills, the insulating snow cover is thinner or absent, meaning that the plant is hardly protected from freezing temperatures.
Sometimes you just have to get down on your knees to reach all the plants. The more beautiful the setting, the more enjoyable the work.
In the rainforest, the plot sizes must be significantly larger than in the subalpine heathlands of Norway, as the species diversity is considerably higher. In terms of tree species alone, up to 400 tree species per hectare can be found in the Atlantic rainforest of Brazil. That is 400 more than above the tree line in the mountains.
Specialists such as these “living stones” (Lithops spec.) are adapted to the extremely dry environmental conditions in the Namib Desert. The leaves have windows that allow sunlight to pass through so that the plant can photosynthesize. At the same time, the sensitive areas of the leaf are protected from damage by high solar radiation through pigmentation. In addition, the species forms a taproot that allows it to reach water in deeper layers and has the ability to store water underground. Such specialists are often difficult to promote in the context of urban biodiversity because they are sensitive to human disturbance. Not all biodiversity is the same – a high number of species, consisting mainly of generalists and disturbance indicators, is different from a species-poor but highly specialized flora that is threatened by even minor fluctuations in environmental conditions. Such details were taken up and discussed in a series of lectures on the topic of “Urban Biodiversity and Green Infrastructure” developed with African cooperation partners.
Ruderal area used for urban agriculture in the heart of Wuxi, China. Due to limited usable space, conflicts often arise between stakeholders such as construction companies, conservationists, and residents. Nevertheless, biodiversity in urban areas is essential for cities that are livable in the future—for a more pleasant urban climate, for water management by reducing above-ground runoff, as a refuge for plants and animals, and, last but not least, for an aesthetic living space for us humans, where we feel comfortable and can identify with our surroundings. In a research project together with landscape architects and architects, we investigated how biodiversity, in combination with open space design and architectural style, can influence locality, which is considered a key factor for quality of life in cities.
We humans change our environment in many ways that also affect other living beings. Artificial light, for example, is emitted in large quantities, in varying intensities, wavelengths, and time periods. Plants use light to generate energy through photosynthesis and as a timer for their developmental processes. The influence of artificial light on plant development is not yet fully understood. In student projects, we have shown that both biomass and the number of flowers and fruits can be influenced by light, which has a direct impact on fitness—with possible consequences for the evolutionary adaptation of plants to urban conditions.

Participation in research projects

09/2024 - 09/2027      Are annual plants escaping the root economics space? Root functional traits in the annual model grass Brachypodium hybridum under increasing aridity

05/2016 – 04/2019     Urbanization and Locality: Preserving and Developing Identity in Large-Scale Urbanization Processes with Urban Landscapes along Canals as Case Studies (Sino-German Center for Research Promotion, DFG)

02/2015 – 02/2018     Green Infrastructure and Urban Biodiversity in sub-Saharan Africa (DAAD)

09/2012 – 02/2014     Local adaption and gene flow in Empetrum hermaphroditum, a keystone species of boreal and arctic ecosystems, along an altitudinal stress gradient (DFG)

 

Supervised theses

2022                          

  • Pörtner, D.:  Potenzielle Auswirkungen einer klimabegründeten Ausweitung des Douglasienanbaus auf die biotische Diversität anhand des Vergleichs der Struktur-Unterschiede von Douglasienbeständen zu Buchenbeständen im Teutoburger Wald (M.Sc. Thesis)
  • Seehaus, R.: Minimierung der ökologischen Auswirkungen von Entschlammungsmaßnahmen auf kleine Stillgewässer (B. Sc. Thesis)
  • Thiery, H.: Human-induced biodiversity and its relevance for nature conservation (B.Sc. Thesis)

2021

  • Leipert, F.: Einfluss eines verlängerten Beleuchtungsregimes auf die Keimungsrate und den Keimungsverlauf von Cerastium semidecandrum (B. Sc. Thesis)
  • Strack, S.: Der Einfluss von künstlichem Licht bei Nacht auf die Trockenmasse und Blütenanzahl von Lamium purpureum in Hannover (B. Sc. Thesis)

2020                          

  • Krüger, S.: Factors influencing the plant species and habitat type diversity of urban green spaces (M. Sc. Thesis)
  • Fleer, A.: Potenziale der Permakultur zur Verbesserung der Phytodiversität in der Agrarlandschaft (B. Sc. Thesis)

2019                           

  • Schlätel, M.: Assessment and Conservational Improvement of a Golf Course in Western Ireland (B. Sc. Thesis)
  • Riedel, H.: How to cope with undesired species while planning and designing for biodiversity in urban areas (M. Sc. Thesis)
  • Schneider; G.: Klimawandel und Agrobiodiversität. Ansätze einer naturschutzfachlichen Planungsgrundlage zu den Auswirkungen des Klimawandels auf die Segetalflora von Agrarökosystemen in Brandenburg. (B. Sc. Thesis)                      
  • Tausendfreund, M.: Development of a Mangement Concept for the proposed Hallaydeghe-Asebot National Park in Ethiopia (B.Sc. Thesis)

2018                           

  • Schulz, A.: Entwicklung einer Moorheidevegetation im Naturschutzgebiet Mietenmoor (B. Sc. Thesis)
  •  Philipp, H.: Entwicklung eines Konzeptes zur erfolgreichen Begründung von naturschutzfachlich wertvollem Grünland mittels Mahdgutübertragung (B. Sc. Thesis)

2017                          

  • Schulz, B.: Die Süntel-Buche im Köllnischfeld bei Springe. Erfassung, Analyse und Maßnahmenentwicklung (B. Sc. Thesis)
  • Berger, L.: Entwicklung von Flora und Vegetation in FFH-Lebensräumen in Naturwaldreservaten am Beispiel des Naturwaldreservates Naabrangen (B. Sc. Thesis)

2016                           

  • Bollmann, R.: Pflege von magerem mesophilem Grünland kalkreicher Standorte auf ehemaligen militärischen Übungsflächen am Beispiel des Naturschutzgebietes „Appelhorn“ im Innerstebergland (B. Sc. Thesis)