Lesson 2 of 11 · 5 min
Structure and function
NCERT §12.1
On a trip to a forest reserve near Pune, Ma'am makes the group lie on their backs and look up. 'Tell me how many storeys this building has.'
The lesson in notes
In short
An ecosystem has abiotic (non-living) and biotic (living) components. Their interaction gives each type of ecosystem a characteristic physical structure.
Identifying and counting the plants and animals present tells us the species composition of an ecosystem.
Stratification is the vertical distribution of species at different levels.
In a forest, trees form the top layer, shrubs the second, and herbs and grasses the bottom layers.
The two chief features of an ecosystem's structure are its species composition and its stratification.
An ecosystem works as a unit through four functional aspects: productivity, decomposition, energy flow and nutrient cycling.