Duration
6d FW
Number of credits
Lecturer
Language(s) of instruction
French language
Organisation and examination
Teaching in the second semester
Schedule
Units courses prerequisite and corequisite
Prerequisite or corequisite units are presented within each program
Learning unit contents
Field work in the Cévennes National Park in France. During this this field work, a series of analyses is developed in the field of ecological biogeography. These analyses are based on identifications and inventories of the region's flora at different spatial scales. The aim of this internship is to show students the complexity of community patterns, as a function of various biotic and abiotic factors. More specifically, a theory (Hubbell's theory) is tested, based on different transects developed in several contrasting areas of the Cévennes National Park.
Learning outcomes of the learning unit
At the end of this course, you will have:
- Conceptually integrated a classic ecological theory
- Adopted a hypothetico-deductive approach by proposing a series of hypotheses, implementing a methodology for explicitly testing these hypotheses and interpreting the results obtained in relation to theoretical expectations
- Implemented statistical tests based on the data collected in order to test the hypotheses
Prerequisite knowledge and skills
Have previously taken the Biogeography course
Planned learning activities and teaching methods
Theoretical background
The unified neutral theory of biodiversity and biogeography (UNTBB), published in 2001, develops and supports the idea that the distribution of species belonging to the same trophic level is due solely to ecological drift (demographic factors of extinction and immigration) and not to intrinsic differences between species (niche segregation). This reasoning, which is similar to the island theory of McArthur & Wilson (1963,1967), has the corollary that species frequency is identical whatever the observed geographical scale. It is this latter hypothesis that will be tested during the proposed course. If it is rejected, the two main conditions for the application of Hubbel's theory, namely non-segregation of niches and identity of dispersive capacity between species, are tested. The various hypotheses of the work are as follows: 1. Neutral Hubbell theory:H1. Species distribution frequencies are identical whatever the spatial scale defined; 2. Ecological niche segregation:H2. Species frequencies do not vary with environmental variation; 3. Species dispersive limit:H3. In a defined environment, the spatial distribution of individuals of the same species is not structured, i.e. its frequency is homogeneous in this environment.
Methodology
To test Hubbell's theory, flowering plants are sampled at various sites. Within these sites, different transects are made within clusters. For each transect, the presence/absence of species is assessed in ten one-square-meter cells. The Hubbel hypothesis is tested by analysis of variance to determine whether species frequency is identical at local (intra-site) and regional (inter-site) levels. To test the hypothesis of niche segregation, a Principal Component Analysis (PCA) is performed with each of the species encountered at all sites as variables. The "individuals" here are the transects carried out. The different habitats (calcareous grassland, mesophilous grassland, downy oak woodland and calcareous beech woodland) are associated with the different axes of the PCA via a correlation test. To test the hypothesis of a dispersive limit at short and medium distances, mean species frequencies are compared by analysis of variance at different nested spatial scales.
Mode of delivery (face to face, distance learning, hybrid learning)
Face-to-face course
Course materials and recommended or required readings
Written work / report
Further information:
Students submit a structured report setting out the hypotheses to be tested, the methodology used for each hypothesis test, the results and an interpretation of the results.
Work placement(s)
This course is a field work
Organisational remarks and main changes to the course
Contacts
Alain Vanderpoorten
Bât. B22 - Quartier Vallée 1
chemin de la Vallée 4
4000 Liège 1
Belgique
Email : A.Vanderpoorten@uliege.be
Flavien Collart
Bât. B22 - Quartier Vallée 1
chemin de la Vallée 4
4000 Liège 1
Belgique
Email : fcollart@uliege.be