Computer-based work (strong literature review component)

1.   Individual-based models vs mean-field approach: what do we need?

Topic: In ecology and sociology, the huge variability in behaviour and the large variability in any trait of relevance among individuals has led to a strong push for so-called "individual-based" models, aka "agent-based models". These represent individuals, with fixed traits, but large variation among individuals. Such IBM/ABMs contrast with traditional, "theoretical" models, which are referred to as "mean-field approaches" (MFA).

It can be easily shown, for hypothetical situations, that IBM and MFAs may differ substantially in population dynamics. But does this potential difference actually matter in real systems?

Methods: Literature review of all studies comparing IBM and MFA. In google scholar, "("individual-based model" or "agent-based model") AND "mean field"" yields just over 200 papers, most probably irrelevant.

Suitable as: BSc or MSc thesis project

Time: A start is possible at any time.

Requirements: Interests in rather abstract system descriptions and model behaviour; meta-analysis.

Contact: carsten.dormann@biom.uni-freiburg.de

 2.   Effect of close-to-nature recreational activities on wildlife behaviour, contrasting hunting and non-hunting zones [Literature review]

National parks serve the dual purpose of conservation and recreation. However, park visitors may affect wildlife behaviour, such as day-night-activity patterns, habitat use or uphill migration. How animals respond to visitors seems to depend hugely on the type of activity (hiking or paragliding, mountain-biking or cross-country skiing), as well as on the individual animal's experience with humans. Large north American national parks (such as Yellowstone or Banff) host almost tame ungulates, while similar species in most European parks are very timid. This project shall test the hypothesis that it is the hunting history that determines how animals respond to human visitors. After several decades of full protection from hunting, we expect animals to become much less shy. This project shall review existing studies and reports from around the world, contrasting wildlife behaviour in hunting and non-hunting zones. Depending on the material available, the focus would narrow down to ungulates, predators and large birds, and to the northern hemisphere.

Methods

Literature review. First a scoping study will identify the number of studies available. Then species and regions will be selected, and studies with clear 

hunting on/off-regimes identified. Key target behaviours are flight-initiation-distance and day/night activity budgets.

Time: The project can start anytime. Suitable MSc project.

Requirements: Willingness to wade through substantial and scattered publications.

Contact: Carsten Dormann, carsten.dormann@biom.uni-freiburg.de.

3.   Are arthropod communities on trees more strongly determined by tree age or tree species identity? [Literature review with strong quantitative analysis component; multivariate statistics in R]

Topic: Tree diversity experiments, such as the IDENT site in Freiburg, allow clear conclusions about effects of biodiversity and tree species combinations on ecosystem functions, and the underlying mechanisms. But given the relatively small scale of such experiments, it can be challenging how to transfer results to real-world forests.
In the tree diversity experiment IDENT-Freiburg, we have sampled arboreal arthropods over several years now, revealing how biodiversity affects herbivory and arthropod communities.

Aim / Methods: The aim of this thesis is to compile arthropod community data from the literature for the same tree species as planted in the experiment, and compare community composition between the data from the IDENT experiment and data from literature sources with varying tree age. This involves literature search, data extraction and data analysis.

Requirements:
Interest in community ecology and entomology. Some experience with R, ideally with analysis of biodiversity / community data.

Time: project can start anytime. Suitable as BSc or MSc project.

Contact: Jochen Fründ (jochen.fruend@biom.uni-freiburg.de)