Scientist

Faculty of Biology
Aquatic Ecology
Universitätsstrasse 5
D-45141 Essen
Germany

Room S05T03B02
Tel: +49.201.18.33113
Fax: +49.201.18.32179
willem.kaijser@uni-due.de

 Publications

 

PhD thesis: Bio-geochemical drivers of aquatic plant distribution

What do we known about the influence of bio-geochemical drivers on the distribution of aquatic plants?

Firstly, the project started as means to find a solution on the mono-cultures of Elodea nuttallii (Planch.) in lake Baldeney (Essen; Germany). It was proposed that E. nuttallii was removed (dredging) at certain areas in the lake. Hereafter, the growth of E. nuttallii and the effect and changes on the macro-invertebrate communities were follow over time. Unfortunately, the growth of E. nuttallii in the year 2019 started late in the season, which hampered the planning.

Secondly, besides the solution to the mono-cultures of specific species, much less research is focused on plant distribution than to macro-invertebrates. Studies trying to elude important bio-geochemical factors using multi-variate statistics show highly variable results and a general concept is missing. Hence, most consistent factors mentioned are turbidity, salinity and nutrients (N and P). Yet, it is not so that these factors do explain all of the macrophyte distribution. Based on data-sets different models and ideas are test to see what factors and approaches best explains macrophyte distribution.

Lastly, statistical methods are often not an ecologists/biologist/chemists favourite subject. Most calculations and methods are often hard to interpreted without a mathematical background. Currently, I developed some R-functions that are simple to understand and easy to implement in R the idea behind it is that the user could simply trace back how these functions work by the provided literature. Therefore, results are easily to interpret and nuances can be spotted.