Grasslands, the lesson
The big ecosystems on Earth where people can live are mainly forests and grasslands. Grassland, savanna, is where our species started and lived maybe 2 million years. Many natural grasslands are now agricultural areas (many forests too). Somehow people seem to worry more about the loss of forests than about the loss of grasslands.
On this site you find a number of articles on grasslands and protecting them. Read the texts and answer the questions to learn about the problems.
There is a lot of text here. Best is to divide the class in groups, each taking one of the texts and reporting about the problem therein.
Or maybe it is a good idea to make a broader study of the problem and write a report, for your school newspaper, local paper or whatever – to make people conscious about the great value of our global heritage, the grasslands.
Flowering meadows good for humankind
The more it swarms, crawls and flies the better it is for humans. A diverse ecosystem populated by many species from all levels of the food chain provides higher levels of ecosystem services.
Read the text: Flowering meadows
1. What do we mean by ‘ecosystem services’?
2. In modern agriculture meadows mostly have very few colorful flowers. Why do modern farmers prefer meadows consisting of only one or a few species of grasses?
3. What is the food chain in a modern meadow?. And how can a food web in a flowering meadow look like? Make a schematical drawing of each to show the difference.
Read the text: ‘Decreasing biodiversity etc
4. What is the productivity of a plant?
5. What is ‘resource acquisition’ of plants? Which are the resources of plants? How can this be influenced by the diversity of the ecosystem?
6. Modern meadows without (wild) flowers are preferred by farmers because they are more productive. Which productivity does the farmer mean and which productivity is meant in this text? Why are they different?
7. There is a link between loss of biodiversity and poverty – especially in ‘Third World’ countries. Can you explain that? Find examples.
Read the text: ‘Too much of a good thing’
8. Why are fertilizers ‘a good thing’?
9. Organic farmers do not use chemical fertilizers. Why are they also a ‘bad thing’? What do the organic farmers use to keep the soil fertile?
10. Nitrogen is the most important element in fertilizers. Why/how is N often lost from the natural nitrogen cycle?
11. Scientists tell us that 2 billion people are alive today thanks to nitrogen fertilizing. This stuff was invented in the end of the 19th century. How did people survive before that time?
12. So, we cannot do without the fertilizers. What should be done to protect the biodiversity and at the same time feed the people?
Read the text: Forest conservation may be hurting grasslands
Tropical grassy biomes (TGBs) are characterized by an abundance of fire-tolerant grasses that thrive under dry conditions. They are not entirely treeless. It is often not very clear to make a difference between an open forest and a grassland with some trees. In the reforestation programs people are eager to plant trees, damaging some grasslands, that for instance can profit from occasionally fires.
13. Local people often do not like international reforestation programs like REDD+. Can you understand why? Explain.
14. How can an ecosystem profit from an occasional fire?
15. Tropical Grassy Biomes (TGB’s) can be found globally where it is too dry for forest. Why are grasses better able to survive in places with little rain? and survive fire?
16. Why do international programs insist on reforestation?
17. One reason why people want more forest is that they want trapping as much carbon as possible. Natural grasslands also trap a lot of carbon. Grasslands used for food production do not. Explain.
18. Why is it not always easy to decide if a certain landscape is wooded savanna or open forest.
19. How can natural grasslands feed the local people? And forests?
20. The oldest humans lived in the savanna of eastern Africa. They were hunters/gatherers. Where can we still find hunters/gatherers in the same landscape? Do you think they live exactly like the early humans? Explain.
21. Find out what the original ecosystem was in the place where you yourself live today. Was it forest, grassland or something else? How did people live in your place before ‘civilisation’ came?
Read also related articles:
About trees against desertificatien
Forests can play key role to end global hunger