Lesson video

Hello, and welcome.

My name is Ms. Harrison.

I'm so excited to be learning with you today.

Today's lesson is called Causes of Biodiversity Loss in the Taiga Biome.

Grab everything you might need for today's lesson, and let's begin our learning.

By the end of this lesson, you'll be able to describe how acid precipitation, forest fires, and pests and diseases contribute to a loss of biodiversity in the taiga.

Before we can begin this learning, we need to define the keywords that we'll be using throughout today's lesson.

The keywords in today's lesson are biodiversity, habitats, and climate change.

Biodiversity, this is a measure of how many different species live in an ecosystem.

Habitat, this is the natural place where a plant or animal lives and grows.

Climate change, this is the long-term changes in temperature, weather patterns, and atmospheric conditions resulting from human activities like burning fossil fuels.

Now that we've defined these keywords, we can begin our learning.

The first question we're going to explore in today's lesson is: Why is the taiga vulnerable to threats? The taiga biome is the world's largest terrestrial biome, spanning vast areas of Canada, Russia, Alaska in the United States of America, and Scandinavia.

It stretches across the Northern Hemisphere, forming a broad, continuous belt of forest that plays a key role in the global ecosystem.

While the taiga has a lower biodiversity compared to more tropical regions, like the tropical rainforest, it still supports a wide variety of plant and animal species.

The harsh climate, characterised by long, cold winters and short, cool summers, has shaped the unique ecosystems of the taiga.

Despite these challenging conditions, the biome hosts many species of trees, such as spruce and pine, with a variety of mosses and wildflowers.

In terms of wildlife, the taiga is home to several iconic species, including wolves, bears, lynx, and caribou, as well as numerous bird species like owls, eagles, and woodpeckers.

While the biodiversity may be lower than in tropical forests, the taiga is still incredibly important for global wildlife and serves as a vital habitat for many species that have adapted to its extreme conditions.

The taiga has naturally lower biodiversity compared to warmer biomes due to its harsh climate and short growing seasons.

The cold temperatures and long winters limit the types of species that can survive there, and the growing season's brief, restricting plant growth and reproduction.

As a result, fewer species are able to thrive in the taiga's challenging environment.

The recovery from human activity is much slower in the taiga.

The cold climate means that plant life grows at a much slower pace, and the slow regeneration of vegetation delays the restoration of ecosystems that have been damaged by logging, mining, or other commercial activities.

As a result, it can take decades or even centuries for ecosystems to fully recover, making the taiga highly vulnerable to long-term environmental changes.

Slow decomposition occurs in the cold temperatures of the taiga, as the cold slows down the breakdown of organic matter.

Additionally, the acidic soil, created by the accumulation of fallen pine needles, further reduces the rate of decomposition.

Because of this, nutrients are not readily returned to the soil, and the nutrient cycle in the taiga is slow.

As a result, the soil is poor in nutrients, which limits the growth of plants and slows overall rate of plant growth.

This makes the taiga a challenging environment for vegetation to thrive and recover, contributing to the biome's low biodiversity.

Let's take a look at how long it takes for a plant to grow.

0-5 years, seedlings grow very slowly.

10-30 years, trees reach 1 to 3 metres.

30-50 years, trees reach 5 to 10 metres.

And 50-100 years, trees reach 15 to 30 metres.

As you can see, it takes a really, really long time for trees to grow.

Animal and plant species in the taiga need to be highly adapted to survive the biome's harsh conditions, such as long, cold winters and short growing seasons.

These adaptations include things like thick fur or hibernation for animals and evergreen needles or deep roots for plants.

While these specialised traits allow them to thrive in the taiga, they also make them particularly vulnerable to ecosystem changes.

If environmental conditions shift due to factors like climate change or human activities, species that are highly specialised may struggle to adapt as their survival is tied to very specific environmental conditions.

This lack of flexibility makes the taiga ecosystem more fragile and sensitive to disturbances.

Let's take a look at some of the adaptations.

They can change their fur colour for seasonal camouflage.

They have large paws for walking on the snow.

And needle-like leaves to reduce water loss.

The taiga biome is home to vast stretches of frozen soil called permafrost, which plays a critical role in regulating Earth's climate by storing large amounts of carbon.

This carbon has been trapped in the frozen ground for thousands of years, remaining safely locked away and preventing it from entering the atmosphere.

However, as global warming temperatures rise due to climate change, the permafrost is starting to thaw at an alarming rate.

As permafrost thaws, the carbon that was previously locked in the soil is released into the atmosphere as carbon dioxide and methane, both of which are powerful greenhouse gases.

This release of greenhouse gases accelerates the process of global warming, contributing to even higher temperatures in the future.

This results is dangerous feedback loop.

As the permafrost melts and releases more carbon, it further intensifies climate change, which in turn causes even more thawing.

The consequences of this thawing go beyond just the release of carbon.

It can lead to the collapse of ecosystems, as plants and animal species are exposed to rapidly changing conditions that they may not be able to adapt to.

The thawing of permafrost also disrupts local infrastructure, such as roads, buildings, and pipelines, making life in the taiga increasingly difficult for people and wildlife.

In the long run, the release of carbon from permafrost could contribute significantly to rising global temperatures and the disruption of ecosystems worldwide, making the health of the taiga increasingly critical for the entire planet.

Why is the taiga particularly vulnerable to environmental threats like deforestation and climate change? Is it A, the animals in the taiga can quickly adapt to new environments? B, plants grow slowly, and permafrost limits soil nutrients? C, the taiga has warm temperatures year-round, helping fast recovery? D, species are so specialised for taiga conditions that they struggle with ecosystem changes? Pause the video here whilst you decide if this statement is true or false, and press play when you're ready to continue.

Excellent, the answer is B, plants grow slowly, and permafrost limits soil nutrients.

And D, species are so specialised for the taiga conditions that they struggle with ecosystem changes.

Well done if you managed to identify those correctly.

True or false? The taiga recovers quickly from damage because its animals and plants can easily adapt to change.

Pause the video here whilst you decide if this statement is true or false, and press play when you're ready to continue.

Fantastic, this statement is false.

I would now like you to explain why.

Pause the video here and press play when you're ready to continue.

Fantastic, the reason why this statement is false is because the taiga is slow to recover because plants grow very slowly due to nutrient-poor soils, and animals are highly specialised to the harsh conditions, making it hard for them to survive if the habitat changes.

Well done if you managed to explain that correctly.

I would like you to fill in the blanks using the words below.

The text is about why the taiga is vulnerable to threats.

Pause the video here whilst you attempt this task, and press play when you're ready to continue.

Excellent work.

Let's check our answers.

Your answer should read like this: The taiga is a fragile ecosystem because its plants grow very slowly, making it difficult for forests to recover from disturbances like deforestation.

The permafrost acts as a carbon sink, storing large amounts of carbon that can be released when it melts, contributing to climate change.

Many animals in the taiga are specially adapted to the harsh conditions, meaning they struggle to survive if their habitat is damaged or changed.

Well done if you managed to answer those questions correctly.

You've done brilliantly.

We're now going to explore our second question of today's lesson: What is causing biodiversity loss in the taiga? Acid rain is caused by the release of sulphur dioxide and nitrogen oxides from industrial emissions, particularly from activities like mining, oil sands extractions, and fossil fuel combustion.

When these gases are released into the atmosphere, they combine with water vapour to form sulfuric acid and nitric acid.

These acids then dissolve into rain, snow, and fog, making the precipitation acidic.

Acid rain can damage plants, harm aquatic ecosystems, and degrade soil quality in the taiga, further stressing the already fragile environment.

Acid rain has a significant impact on the biodiversity in the taiga, as it affects both the soil and the water quality.

The acidification of the soil reduces nutrient's availability, which weakens plants and trees, particularly the roots and needles of fir trees.

This makes it harder for these trees to grow and survive, disrupting the forest ecosystem.

Acid rain also acidifies water, lowering the pH levels of rivers and lakes, which in turn lowers fish populations.

Fish species such as salmon and trout are particularly sensitive to changes in water acidity, and as their numbers decline, it impacts other species that depend on them for food.

The disruption of the food web results in broader consequences for the taiga's biodiversity, as the decline of one of species affects many others throughout the ecosystem.

Industrial emissions from Sudbury nickel and copper mines in the USA contribute significantly to acid rain in Canada's taiga.

Over the past several decades, this acid rain has had devastating effects on the ecosystems. It's damaged black spruce and jack pine trees, weakening their growth and survival due to the acidification of soil.

The acid rain has also acidified lakes, lowering the pH levels and causing a decline in fish populations, particularly those sensitive to changes in water chemistry.

As fish populations decrease, other species that rely on them for food are also affected, further disrupting the food webs in the taiga.

Additionally, the acid rain has reduced lichen growth, which is crucial for many organisms in the taiga, including herbivores like caribou.

The loss of lichen and other plant species negatively impact the entire ecosystem as the taiga's delicate food web becomes increasingly fragile.

What impact did acid rain from the Sudbury's mine have on biodiversity in Canada's taiga? Is it A, increased plant growth and biodiversity? B, improved water quality, benefiting aquatic life? C, caused tree loss and harmed aquatic ecosystems? D, Boosted the population of fish and other aquatic species? Pause the video here whilst you attempt this task, and press play when you're ready to continue.

Fantastic, the answer is C: it caused tree loss and harmed aquatic ecosystems. Well done if you identified that correctly.

True or false? Acid precipitation in the taiga is primarily caused by the natural weather patterns.

Pause the video here whilst you decide, and press play when you're ready to continue.

Excellent, the answer is false.

I would now like you to explain why this statement is false.

Pause the video here whilst you attempt this task, and press play when you're ready to continue.

Excellent.

The reason why this statement is false is because acid precipitation is mostly caused by human activities such as burning fossil fuels and mining, which release sulphur dioxide and nitrogen oxides into the atmosphere, harming plants and animals.

Fantastic work on this.

Forest fires are a natural and regular feature of the taiga biome.

The taiga is adapted to these fires, as many plant species, like pine trees, rely on the fires to regenerate.

Some trees even have fire-resistant bark, and their seeds are often released after being exposed to heat, helping with biodiversity renewal.

While forest fires can contribute to the renewal of biodiversity, the increasing impacts of climate change have made these fires more frequent and severe than the taiga species are naturally adapted to cope with.

Higher temperatures, prolonged droughts, and changing weather patterns have created conditions that allow fires to spread more rapidly, burning areas that would have otherwise recovered in a more gradual way.

This puts extra stress on the taiga ecosystem, disrupting the balance and potentially causing permanent damage to the environment.

GIS can be used to track wildfires in Canada.

The map on your screen shows wildfires between 2012 to 2022, and as we can see, it shows an increase in wildfire instances in Canada's taiga.

The increase in forest fires and the growing area affected by them are having profound impact on biodiversity in the taiga.

The fires disrupt habitats and put species at risks in several ways.

Fires displace birds and mammals that depend on old-growth forests for food, shelter, and nesting sites.

These species are forced to find new habitats, often in areas already under stress from other environmental factors.

Fires kill animals that are unable to escape in time, particularly those with limited mobility or those trapped in smaller areas of habitat.

Certain tree species, like white spruce, take a long time to recolonize an area after a fire.

This slow regeneration process means that many ecosystems struggle to recover, leaving the land vulnerable to further degradation and loss of species.

Additionally, fires release massive amounts of carbon dioxide into the atmosphere, further worsening climate change.

This creates a vicious cycle, increasing global temperatures which lead to more frequent and severe fires, which in turn exacerbate stress on taiga species, making it harder for them to survive.

The cumulative effect of these fires is the decline in biodiversity and a destabilisation of the taiga ecosystem, which already faces significant pressures from human activities and climate change.

In 2016, Fort McMurray in Canada experienced severe wildfires that had devastating impacts on the regions.

Over 600,000 hectares of forests were destroyed, significantly altering the landscape and disrupting local ecosystems. The fire also had harmful consequences.

Smoke and ash from the fires polluted rivers, contaminating water sources and affecting aquatic life.

The loss of plants and prey species led to food shortages for animals in the area, putting additional stress on wildlife and disrupting the local food web.

These fires highlighted the growing threat of wildfire intensity in the taiga, particularly as climate change continues to make such events more frequent and severe.

The Fort McMurray wildfire of 2016 was significant because: A, it was the largest wildfire in history.

B, it destroyed over 600,000 hectares of taiga forest.

C, it was caused by an oil spill.

D, it was completely natural with no human influence.

Pause the video here whilst you attempt this task, and press play when you're ready to continue.

Excellent, the answer is B, it destroyed over 600,000 hectares of taiga forest.

Well done if you identified that correctly.

True or false? All wildfires in the taiga are harmful and should be prevented.

Pause the video here whilst you attempt this task, and press play when you're ready to continue.

Excellent, this statement is false.

I would now like you to explain why this statement is false.

Pause the video here and press play when you're ready to continue.

Fantastic, the reason why the statement is false is because some wildfires are natural and necessary for ecosystem renewal, as they clear old vegetation and help new trees grow.

However, climate change has made fires more intense and frequent.

Well done if you managed to explain that correctly.

The extremely cold winters of the taiga biome historically acts as a natural barrier, keeping many pests and diseases from invading the region.

This harsh climate protected the taiga's ecosystem from the spread of invasive species that could potentially disrupt the balance of plant and animal life.

However, with the rise of climate change, warmer temperatures are gradually allowing these pests and diseases to extend their range northward, encroaching on the taiga.

Taiga species have evolved in this environment and are not naturally equipped to resist these newly arriving threats.

Many species of trees, plants, and animals in the taiga have no built-in defence mechanism against pests such as the spruce bark beetle, or diseases like fungal infections, which are now becoming more prevalent due to milder winters.

As this invasive species spread, they cause significant harm, weakening the health of native plants and animals and, in some cases, leading to population declines.

The introduction of these pests also disrupts the delicate balance of the taiga ecosystem, leading to changes in food webs and threatening biodiversity.

This shift poses a serious risk to the integrity of the taiga and its ability to support the species that depend on it.

Warmer temperatures and milder winters are allowing pests like the spruce bark beetle and pine beetle to thrive in the taiga.

These pests are able to survive through the winter more easily, leading to a significant increase in their population.

As a result, they're killing millions of trees, which weakens overall health of the forest.

The forest, already stressed by climate change and acid rain, are becoming even more vulnerable to these pests.

The weakened trees are less able to resist infestations, making the forest not only more susceptible to pest damage but also more flammable, increasing the risk of wildfires.

Additionally, the loss of trees reduces the availability of food and habitat for animals, further disrupting the taiga's delicate ecosystem.

Invasive species and diseases pose a serious threat to the biodiversity in the taiga, and the impact is widespread and long-lasting.

Pests like the spruce bark beetle and pine beetle, which are not native to the taiga, attack and kill millions of trees that lack the natural defences to resist these invaders.

The mass die-off of trees disrupts the rainforest structure, diminishing the habitat for a wide variety of species, from birds to small animals who rely on these trees for shelter or for food.

The fallen, dead trees from these infestations don't just create an eyesore, they become dry fuel that significantly increases the likelihood and severity of wildfires in the taiga.

These fires are particularly devastating, as climate change makes them more intense and frequent, compounding the damage to the ecosystem.

As forests burn, the regenerative process is slowed even further, and the delicate balance between the environment is disrupted.

Beyond the immediate damage to trees, the consequence ripples through the entire food web.

Species that rely on these healthy trees for resources, whether for food, nesting sites, or shelter, begin to suffer.

For example, woodpeckers that depend on bark beetle larvae for food or various bat species that use trees for nesting face significant population declines.

These disruptions affect the entire ecosystem, from insects to large herbivores and even apex predators, as they're all interconnected in the taiga's delicate web of life.

The cumulative effects of these pest infestations reduce the overall resilience of the taiga, making it harder for the ecosystem to recover and maintain its biodiversity.

The mountain pine beetle in Canada has caused significant damage to taiga biodiversity, particularly in British Columbia.

Over 16 million hectares of forests have been destroyed, 80% of lodgepole pines have been killed.

This extensive tree loss disrupts the food web, putting at risk many species that depend on these pines for food and shelter.

The large number of dead trees also increases the risk of wildfires, as they provide dry fuel, which doubles the chance of fire outbreaks.

The combination of habitat destruction and greater fire risk creates a dangerous cycle that further destabilises the taiga ecosystem, making it harder for species to thrive and recover.

True or false? Invasive pest outbreaks in the taiga have increased due to rising global temperatures.

Pause the video here whilst you decide if this statement is true or false, and press play when you're ready to continue.

Fantastic, this statement is true.

I would now like you to explain why this statement is true.

Pause the video here and press play when you're ready to continue.

Fantastic, the reason why it's true is because warmer winters allow pests like spruce bark beetle and mountain pine beetle to survive longer and spread further, damaging forests and increasing wildfire risks.

Well done if you managed to explain that correctly.

How have invasive pests and diseases contributed to the loss of biodiversity in the taiga? Is it A, they have led to increased tree growth and diversity? B, diseases have strengthened the resistance of tree species in the taiga? C, they have caused an increase in animal populations by providing more food sources? Or D, pests like mountain pine beetle have killed millions of trees, reducing habitat for wildlife? Pause the video here and press play when you're ready to continue.

Excellent.

The answer is D, pests like mountain pine beetle have killed millions of trees, reducing habitat for wildlife.

Well done on this task.

You are an environmental activist concerned about the loss of biodiversity in the taiga.

I would like you to write a formal letter to a conservation organisation urging them to take action to protect the taiga.

In your answer, you can include what you already know about forest management to suggest things that the organisation could do to reduce biodiversity loss in the taiga.

Andeep has said that he's going to write about the impact of invasive pests and diseases like the mountain pine beetle in Canada.

Pause the video here whilst you attempt this task, and press play when you're ready to continue.

Fantastic, let's check our answers.

Your answer may include some of the following points: Dear Taiga Conservation Organisation, I'm writing to express my concern about the serious loss of biodiversity in the taiga due to human and environmental factors.

The primary causes of this decline are acid rain, forest fires, and pests and diseases, which are having a devastating effect on the ecosystem.

The Fort McMurray wildfires have further contributed to biodiversity loss.

In 2016, over 600,000 hectares of boreal forests were destroyed, killing countless plants and animals.

The loss of vegetation has left many species, such as moose and woodland caribou, without shelter and food.

These fires also released large amounts of carbon into the atmosphere, contributing further to climate change and more frequent fires in the future.

Finally, the spread of pests like the mountain pine beetle has worsened the situation.

Warm temperatures are allowing these pests to thrive, killing millions of trees and reducing habitat for wildlife.

These infestations are making it more difficult for species like caribou to find food, as the loss of trees and plants disrupt the food chain.

To address these issues, I believe your organisation can take several important actions.

First, pushing for stricter regulations on industrial emissions would reduce acid rain.

Supporting fire management programmes and replanting areas affected by the Fort McMurray wildfires would help the forest recover.

Finally, promoting research into pest control could help mitigate the effects of invasive species.

Excellent work on this task.

You've done brilliantly.

We've now come to the end of our learning on causes of biodiversity loss in the taiga biome, and you've done fantastically.

Before we end this lesson, let's summarise everything we've learned today.

The taiga biome is facing a significant decline in biodiversity due to several escalating environmental threats, which are interconnected and exacerbated by climate change.

Acid rain, caused by industrial emissions such as sulphur dioxide and nitrogen oxides from mining, oil extraction, and fossil fuel combustion, have become a major issue for the taiga.

The acidic precipitation damages trees, weakens their structure, and making them more vulnerable to pests and diseases.

It also acidifies the soil and water, disrupting the nutrient cycle and making it harder for plants to thrive.

Acidified rivers and lakes harm aquatic species, particularly fish, reducing biodiversity in both terrestrial and aquatic ecosystems. The combined damage to trees and water sources harms wildlife by reducing food availability and habitat quality.

Forest fires, which are increasing due to climate change, destroy habitats, release carbon dioxide back into the atmosphere, and disrupt food chains.

The spread of invasive pests and diseases is another significant threat to the taiga.

As climate conditions warm, pests like the mountain pine beetle are able to thrive and spread into areas where they previously could not.

The mountain pine beetle, for instance, has decimated millions of hectares of trees, particularly lodgepole pines, which play a crucial role in the forest structure and food webs, as animals that rely on the trees for food or for shelter lose their habitat.

The death of trees also leaves behind dry fuel that increases the risk of wildfires, compounding the problem further.

Each of these threats, acid rain, forest fires, and invasive pests, interact with the others, weakening the resilience of the taiga, making it more difficult for the biome to recover.

Together, they're driving a rapid decline in biodiversity, threatening the survival of many species that are highly specialised to the taiga environment.

Well done in today's lesson.

You've done brilliantly, and I look forward to learn with you again very soon.