B18.4 Deforestation and peat destruction AQA GCSE Biology

Summary

This lesson focuses on deforestation and peat bog destruction, explaining the environmental impacts and human activities driving these processes. It covers how deforestation contributes to global warming, loss of biodiversity, and the effects of burning biomass. The lesson also delves into the significance of peat bogs as carbon stores and habitats, highlighting the consequences of their destruction. Students are encouraged to connect these environmental issues to the broader impact on the climate, and are tasked with suggesting laws to reduce peat consumption and preserve biodiversity. The session includes practical activities, reflection tasks, and exam-style questions to test understanding.

Takeaways

• 😀 Deforestation and peat bog destruction are major environmental concerns, causing significant damage to biodiversity and contributing to global warming.
• 🌍 Deforestation releases carbon dioxide into the atmosphere and reduces the Earth's ability to absorb it, worsening the carbon cycle imbalance.
• 🔥 Burning biomass (e.g., trees and plants) and fossil fuels are key processes that increase carbon dioxide levels in the atmosphere.
• 🌱 Photosynthesis is the only process that removes carbon dioxide from the atmosphere, highlighting the importance of forests and plants in carbon regulation.
• 🌳 Rainforests are often referred to as the 'lungs of the Earth' because they take in carbon dioxide and release oxygen, which is vital for life on Earth.
• 🌾 Humans clear forests for various purposes including timber, farming for crops like biofuels, and cattle ranching.
• 🐄 The livestock industry, particularly cattle farming, significantly contributes to methane emissions, a potent greenhouse gas.
• 🍚 Rice paddies also produce methane, as anaerobic conditions in flooded fields encourage its formation, further contributing to global warming.
• 🌿 Peat bogs are unique ecosystems rich in biodiversity and crucial for carbon storage, as they preserve plant matter that doesn't fully decay.
• ⚠️ The destruction of peat bogs and rainforests poses ethical concerns, as it endangers species that depend on these ecosystems, including potential medicinal plants and animals.
• 🛑 Peat is still used for gardening and burning, despite its environmental impact, with some companies continuing to promote its use, which contributes to the destruction of peat bogs.

Q & A

What is deforestation and how does it occur?

Deforestation is the process of clearing or cutting down forests for human use, such as timber harvesting, agricultural expansion, or urban development. This often involves burning or logging trees, which disrupts ecosystems and contributes to climate change.

How does deforestation contribute to global warming?

Deforestation contributes to global warming in two main ways: by removing trees that naturally absorb carbon dioxide through photosynthesis, and by releasing additional carbon dioxide into the atmosphere when trees are burned for land clearance or fuel.

What is slash-and-burn deforestation, and why is it harmful?

Slash-and-burn deforestation is a method where trees are cut down and then burned to clear land. It is harmful because it releases significant amounts of carbon dioxide into the atmosphere and eliminates the ability of the forest to absorb carbon, exacerbating global warming.

What are some uses of land after rainforests are cleared?

After rainforests are cleared, the land is often used for farming crops such as corn for biofuels, raising cattle, or creating rice paddy fields. Each of these practices also contributes to the release of greenhouse gases like methane.

How does deforestation affect biodiversity?

Deforestation leads to the loss of biodiversity by destroying the habitats of various plant and animal species. Many species rely on the rainforest ecosystem for food, shelter, and breeding, and their loss can disrupt entire food webs.

What are peat bogs, and why are they important?

Peat bogs are wetlands with acidic, waterlogged soil where plant matter does not fully decompose. These bogs are important because they act as carbon sinks, storing large amounts of carbon that would otherwise contribute to global warming.

Why are peat bogs being destroyed, and what are the consequences?

Peat bogs are being destroyed for various reasons, including extraction for use in gardening products, burning as fuel, and land development. This destruction releases stored carbon into the atmosphere and diminishes biodiversity, which is crucial for ecosystem health.

What is the significance of the historical find in peat bogs, such as the body from the fourth century BC?

The discovery of preserved bodies in peat bogs, such as the fourth-century BC man, highlights the slow decomposition process in these environments. This is due to the acidic, low-oxygen conditions that prevent microorganisms from breaking down organic matter, which preserves it for thousands of years.

How does farming livestock, especially cows, contribute to climate change?

Farming livestock, particularly cows, contributes to climate change through the production of methane, a potent greenhouse gas. Cows release methane during digestion (burping and farting), which adds to the warming effects on the planet.

What measures could be taken to reduce the destruction of peat bogs and deforestation?

Measures to reduce destruction include implementing laws to prohibit peat extraction, encouraging sustainable alternatives to peat for gardening, and incentivizing composting. Additionally, reducing the demand for palm oil, beef, and other deforestation-linked products can also help reduce the overall environmental impact.