Forest Ecosystem Dynamics and Succession

The video explores how ecosystems evolve from barren rock to mature forests through primary succession. It highlights the roles of biotic and abiotic factors, starting with the colonization of lava by lyen and ferns, which initiate soil formation. As ecosystems develop, early colonizers like lyen and plants with symbiotic relationships with fungi establish themselves. Over time, these ecosystems transition into mature forests with diverse species, including trees that rely on animal dispersal and require more nutrients.

What are the two main factors that shape ecosystems?

• Biotic and abiotic factors

• Temperature and humidity

• Wind and water

• Soil and air

What initiates the soil formation process in the earliest stage of succession?

• Lichen and small ferns

• Animal activity

• Sunlight

• Rainfall

What is the significance of nitrogen fixation by lichens?

• It increases sunlight absorption

• It helps in breaking down rocks

• It enriches the soil with nutrients

• It attracts early colonizers

Which characteristic is common among early colonizers?

• Dependence on animal dispersal

• Fast growth and need for light

• Shade tolerance

• Slow growth

What role do lichens play in the development of an ecosystem?

• They increase water retention

• They attract animals

• They break up rock surfaces and start soil formation

• They provide shade

Which of the following is NOT a characteristic of early colonizers?

• Need for light

• Wind dispersal

• Shade tolerance

• Fast growth

What is a key feature of the ecosystem as it progresses towards a closed forest?

• Decrease in soil

• Dominance of lichens

• Reduction in plant height

• Increase in moss and soil

What is a characteristic of tree species in a mature forest?

• They require little nutrients

• They are wind-dispersed

• They grow quickly

• They have large fruits and are animal-dispersed

How old is the mature forest described in the video?

• 100 years

• 200 years

• 300 years

• 400 years

What is the primary method of dispersal for trees in a mature forest?

• Wind

• Water

• Animals

• Gravity