Objective: Understanding the correlations of ground degradation and decrease of biodiversity and finding solutions.
Learning outcomes: At the end of this unit, students are able to understand the correlations between ground degradation and decrease of biodiversity and gathering ideas about what to do against ground degradation.
Previous knowledge: Knowledge about ground degradation and related geographical terms. Previous knowledge about biodiversity.
Duration: 30 min
Materials / Conditions: Text (cf. Resources) and searching the internet
Methods / Techniques: partner work, quiz, problem solving
Learning subject: Biodiversity / Module 2: biodiversity and environmental protection / Level: expert learning
On the island Fogo in Cabo Verde there are many plant species that are threatened by extinction for several reasons. There’s a protected area on Fogo called Parque Natural do Fogo which is supposed to ensure the plant diversity on the island. The following text will mainly focus on ground degradation and its effects on plants.
1. Get together with a partner.
2. Read the text you can find in the Resources section.
3. Develop five questions based on the information from the text.
4. Pose the question to your partner and vice versa.
5. Finally, discuss how you could change something about the preconditions.
Ground degradation and its effects on Fogo
Unhindered soil degradation can lead to a complete destruction of the soil’s capacity to (re-)produce as it can be seen at an altitude between 1000 and 1500 m above sea level. Once, the soil there was deep and partly covered with crushed lava but nowadays the slopes are rocky and unfertile. Many roots have been uncovered by wind and water erosion and plants seem to be standing on “pedestals”.
If the vegetation cover was intact, leaves would slow down falling raindrops and strong roots would increase soil stability. While water erosion is responsible for the degradation of fertile soil, wind erosion (deflation) increases land degradation by piling up crushed lava in layers that are several meters high. Dry and strong south-eastern winds that mainly occur around the turn of the year (vento lestre) damage young plants as they carry particles of crushed lava. These winds also lead to a drying-out of young plants.
(Translation taken from: Leyens, Teresa, 2001, Biodiversität des geplanten Schutzgebietes auf der Insel Fogo/ Kap Verde Ausarbeitung von Programmen und Maßnahmen zu ihrem nachhaltigen Schutz, Eschborn , S.25. Portugiesische Ausgabe: Leyens, T., 2001, Biodiversidade da prevista área protegida na Ilha do Fogo, Cabo Verde.)
Possible results / Results:
Task 3: Question e.g.: What effects does erosion have?
Task 5: Solution: Try to support the plants‘ natural growth, e.g. find ways to increase the roots‘ network.
Author: Shirin Doustmohammadian und Vanessa Hofmann
Aus dem Deutschen übersetzt von Jana Prokaka