Habitat Loss
Invasive Species

Biodiversity is not just a complex web of interactions between living things at the three levels of genetic, species, and ecosystem diversity. The abiotic factors of their environment also have an impact on the health of biodiversity. Changes to Earth’s other subsystems—atmosphere, lithosphere, and hydrosphere—ultimately have an impact on biodiversity.

A famous American biologist, Edward O. Wilson, identified the five biggest impacts human activities have on biodiversity and listed the severity of these impacts in order, using the acronym H.I.P.P.O. Lets’s take a look at what each element means:


Habitat loss, fragmentation, and degradation can lead to the elimination or alteration of the environmental conditions and resources necessary for animals and plants to survive in their habitats, which has impacts at all ecological levels.

A habitat is an area that provides all the necessary resources an individual species needs to survive. An ecosystem can encompass multiple habitats for many different species. When land is cleared for agriculture, development, and infrastructure purposes it removes or restricts some or all of the resources necessary for the support of many different species. 

Here is how habitat loss, degradation, and fragmentation impact the three biodiversity systems discussed in this lesson:

    • Genetic level—Individuals may die off or relocate because there aren’t enough resources to support them, minimizing the gene pool of the species in that area and the species’ ability to adapt to environmental changes.
    • Species-level—The loss of one or multiple species can impact other species that rely on them for resources or support, such as a food source, pollinator, or population regulator. If certain roles aren’t performed to keep the biotic side of the ecosystem in balance, it can lead to changes in the abiotic factors present, such as water quality, soil composition, or the climate of a forest.
    • Ecosystem level—When key species in an ecosystem are lost or unable to perform their roles at the right capacity, ecosystems will change into less productive versions or something different altogether. For example, if too many plants are lost from the Amazon Rainforest, it will become a savannah ecosystem and the oxygen production it provides will be lost as well. These are vital services that the ecosystem provides to every animal, including humans, on the planet.

Steps that can prevent habitat loss

Participate in community projects that create habitats for local species in your area. Our “What is Nature?” Lesson 2 about Pollinators provides all the necessary information to research local species and turn your own garden, school, or community garden into a pollinator paradise.

Promote wildlife corridors and stepping stones that connect natural ecosystem habitats through agricultural lands. Many countries have environmental stewardship schemes to integrate ecosystems into human-managed lands which has a positive outcome for both parties involved. 

Promote and take part in reforestation projects. These projects integrate natural areas and provide corridors for wildlife through human development. Keep your own green spaces filled with diverse native species that provide resources throughout the year.

Lobby your government to reconnect habitats through farmland by implementing ecological corridors like hedgerows and wildflower margins between fragmented ecosystems. 

Take part in, promote, and support polyculture farming techniques, which is the planting of different species in the same area. It supports ecosystem services such as pollination, biological pest control, and nutrient cycling while increasing the nutrient yield in the crops harvested.


Find out how habitat loss is impacting the East African potto and the additional indirect effects it is exposed to. Because of their wide range, they’re not yet at risk. But you’ll be surprise and how they’re being squeezed out. Click the graphic below. Scroll to “Conservation Status.”


Invasive species are organisms that have been intentionally or unintentionally introduced to an area where they are not native. This causes ecological or economic damage. Invasive species can destroy community dynamics, leading to the permanent alteration of their habitats, and even the extinction of other species. Unlike species that naturally occur in an ecosystem, nonnative species do not have the same natural controls that develop over millions of years of co-evolution.  

Without regulation, these species can cause negative impacts on the ecosystem in several ways:

    • Competition—Invasive species could outcompete native species for food and shelter. This could remove those native species from parts of their ecosystem, which would impact the other native species that they interact with to collectively support or provide important ecosystem services.  
    • Predators—New to the ecosystem, invasive predators rarely have any natural predators. This allows their population to continually grow, while the prey populations dwindle, impacting the multitude of species that rely on them for various reasons. 
    • Parasites and disease—Some invasive species carry parasites or diseases to which they have developed some level of immunity and can co-exist with little or no impact on their health. However, the native species have not. This can lead to catastrophic loss of life and biodiversity. Think of the impact COVID-19 had on the world, the rate at which it spread, and the loss of life. This is how diseases carried by non-native species can potentially impact populations and communities. 
    • Hybridization—Hybridization is breeding between two distinct species. It can have an important effect on the evolutionary patterns in cross-breeding. This type of interaction impacts species on a genetic level. Over time, the native species can be completely displaced, by the growing hybrid population. Invasions like these can have detrimental impacts on endemic species that do not exist anywhere else.  

Steps that can prevent the impact of invasive species

Invasive species move between ecosystems through routes known as “pathways.” There are many different pathways in which invasive species can be transported. Once a species is established it can be extremely difficult to remove them completely from the ecosystem they have invaded, so prevention is the first line of defense. Here are some simple techniques to ensure you’re not part of the problem.

    • Clean any clothing, shoes, or equipment from hitchhikers (attached organisms) when you travel between locations.
    • Remove any hitchhikers that may have attached to your furry friends.
    • Boat owners should check and remove any species that attach to the hull of their boats between locations.
    • Don’t take things from one ecosystem to other locations. This includes dead and living plants and animals.
    • Plant only native species in your garden.
    • Do not release pets or plants into the wild.
    • Anglers should use native bait when fishing as non-native bait can lead to disease spread.
    • Educate yourself about invasive species in your area and pass on the message. Become an ambassador for the protection of native species.
    • Report any sightings of invasive species.

The second solution is to remove invasive species that have been established. Local parks establish community projects where they will help you to learn and successfully identify invasive species. It is important to ensure you learn from experts in the field as you would not want to accidentally remove important native species.


Look up each of the invasive species below and find out why they are problems within the ecosystems in which they are invasive. (Hint: Asiatic bittersweet is incredibly hardy and chokes out everything in its path, including native plants and trees.)

Listed from top left to bottom right: 1. Asiatic Bittersweet 2. Asian Ladybeetle 3.Channel Catfish 4. Nutria


Pollution can be both natural and manmade. The presence of pollutants in the environment can lead to the degradation of air, soil, and water quality, as well as the overall health of biodiversity. Natural pollutants, such as volcanic ash, can be broken down by ecosystem processes because they are naturally occurring. Manmade pollutants from toxic chemicals are created in unnatural ways that Mother Nature cannot break down. These are called “forever chemicals.”

There are 5 types of human-created pollution that we will identify here:

Air pollution is the modification of natural atmospheric composition by the release of harmful gasses and particles caused by human activity. The main causes of air pollution are the burning of fossil fuels, waste, wood, and dung, and the release of methane from landfills and fertilized fields.  

Because there are so many ways that pollutants are released into the atmosphere, multiple solutions must be implemented to combat them.

    • Conserve energy to reduce the amount of carbon released into the atmosphere. 
    • Use renewable energy where possible.
    • Replace chemical solutions to pest control with natural products or practices. (Chemicals leach into the soil and end up in our food sources and waterways.)
    • Support businesses that follow and implement eco-friendly practices.

Water pollution is caused by chemicals that make water unsafe to use by leaching into groundwater, lakes, and rivers, which ultimately end up in the ocean. Excess fertilizers from agriculture, waste, oil spills, and any release of unnatural products in the form of solids, liquids, or gas can pollute waterways.

Land pollution is impacted by many of the same activities that pollute water. Unnatural chemicals can upset the balance of soil ecosystems that support life. It can also leach into the waterways through groundwater. Excess fertilizer, chemicals from mining practices, and landfill waste are the main culprits and, because they are in the soil, they can ultimately end up on our bodies too.

Water and land pollution are mainly caused by poor business management practices, but there are solutions and actions the general public can take to ensure that best practices are implemented, as well as taking action at home.

    • Learn about the practices the businesses you buy from implement.
    • Support habitats that are by waterways to help filter pollutants before they reach waterways.
    • Buy products from businesses that utilize safe and environmentally friendly practices.
    • Follow the rules of Reduce, Reuse, and Recycle. In that order.
    • Contact businesses and government bodies to let them know that you want them to support and promote better business practices when it comes to the environment.
    • Replace non-degradable products (like plastics) with degradable ones.

Protect habitats and ecosystems because bacteria and fungi are capable of breaking down harmful compounds and turning them into safer forms. 

Noise and Light pollution are pollution in the form of energy. Although they do not emit chemicals or release waste into the environment, they impact the behavior and interactions of species, including human health. They can also indirectly change the chemistry of environments.

Noise pollution has led to behavioral changes in some animal species as they cannot communicate with each other, hunt for prey, or navigate over the noise of factories and cities. Even marine species are impacted by the sound and vibration of vessels through the waters. 

How to reduce the impacts of noise is not so obvious, especially in urbanized areas where everything makes sound. But there are small changes we can make to minimize the impacts we have.

    • Identifying human-caused noise is the best place to start. Then you can begin finding alternatives or even shutting off unnecessary equipment.
    • Use nonmechanical tools or ones that emit a quieter sound to complete work. You can also familiarize yourself with the behaviors of wildlife to ensure you are not conducting noisy work during peak times when wildlife interact.
    • Trees can act as excellent buffer zones for noise between natural and urban environments, so take this into account when making changes to gardens and fields.
    • Lobby your government to preserve, extend, or establish habitats that dampen the noise pollution from cities, industrial estates, and farmland and to prevent transportation routes that run by or through parks and natural environments

Light pollution or, more specifically, artificial light that exists at night, has impacts on humans and animals alike as it confuses our bodies’ natural sleep cycles, as well as emits more CO2. Species guided by the light of the moon, such as migratory birds and sea turtles, can confuse artificial light with the natural light of the moon and travel off course. 

Have you ever seen the night sky in blackout zones? You can sometimes see the Milky Way—it’s breathtaking!

Our society and lifestyle run 24 hours a day in some places, so the complete eradication of light pollution may not be possible. But there are always changes we can make to support our natural world.

    • Only use artificial light where and when necessary, and turn it off when you don’t need it anymore, inside and outside.
    • Focus and shield lights to reduce the impact they have.
    • Use soft white or warm shades, less than 3,000 kelvin bulbs. They also conserve power.
    • Lobby your local council or government to implement these in the streets.


Night sky with Milky Way


Human population. Or rather human OVER population. This is not such an easy topic to address. We, of course, cannot control the rights of other humans. But we can strive to understand how our population growth impacts biodiversity. We might then be able to implement practices that reduce our impact. 

Our planet is a closed system with a finite number of resources. This means that the Earth can only support so many inhabitants. When compounded by the other impacts listed in this chapter, the Earth’s ability to support its inhabitants decreases. 

Population growth of humans has grown exponentially since the 1960s. This has increased our need to extract more resources from the planet. For example:

    • Conversion of natural ecosystems to farmland to produce more crops, and the building of urban environments to live in.
    • The extraction of fossil fuels, and minerals to power our society and build homes.
    • Increased use of freshwater for drinking and industrial processes.

The growth of the human population feeds back into all the other factors that decrease biodiversity in this lesson as well. In fact, they all feed back into each other in some way or another, including the final factor below. So how can we minimize the impacts we have on nature when it comes to our growing population?

    • There may be more people living on planet Earth, year after year, which increases the need for nature’s services. This also means that there are more of us who can choose to make a difference! 
    • By choosing our leaders from local to federal levels we can apply changes to the policies and procedures that govern our country, ensuring that natural habitats are protected for the health and well-being of all life on Earth.
    • Integrate ecosystem studies into our education systems, so that we understand the importance of the natural world around us and what it provides. We can then make conscious decisions about how we utilize the services of our planet.
    • Create community projects and establish societies, organizations, and charities that connect and educate businesses, farmers, and communities about ways they can integrate with nature’s processes, rather than disrupting them so that both human civilizations and nature can prosper together.
As of July 2023, Earth's human population was almost 8.1 BILLION


Overharvesting or overexploiting of plants, animals (hunting), and fish (fishing) is intertwined with the population growth of humans. We exploit certain species for food, building materials, and fuel, to support our growing population. When harvesting of resources exceeds nature’s ability to replenish them, the loss of habitats and species results. 

Here are some ways in which we can all implement sustainable harvesting of these precious resources:

    • Raise awareness to protect nursery habitats for fish stock with Marine Protected Areas so they can repopulate.
    • Lobby your government to implement catch size, fishing quotas, and seasons to fish for commercial fisheries.
    • Support aquaculture businesses that promote healthy management practices.
    • Educate yourself about sustainable forestry practices and protect ancient woodland habitats.
    • Promote selective tree-felling instead of clear-cut felling.


Plants are the producers that bring in all the necessary energy to support all life on our planet and store atmospheric carbon dioxide (CO2) in the process. More plant diversity supports more species higher in the food chain. Plants store carbon by removing it from the atmosphere, all while providing habitats and food sources for other species. Plants keep water in the ecosystem, help stabilize climates, reduce erosion, and filter toxins before entering water and food sources. Appreciate and cultivate plants!

  • If you have access to a backyard or garden space, keep your garden green and plant-rich.
  • Grow your own vegetables and flowers. 
  • Mow lawns after flowering plants have emerge. Some species rely on early spring wildflowers for food. 
  • Protect pollinators by providing them with a safe and nurturning habitat (Lesson 2-Pollinators).
  • Don’t use toxic chemicals in your garden. They kill off beneficial species and can end up in the food you grow! 
  • Don’t throw away your autumn leaves. Rake them into flower beds instead. Many important pollinators and garden species overwinter in the leaf litter. Doing so will also add to fertility to your soil as the leaves break down and become new soil.
  • If you live in an urban area, community gardens are springing up all over. Join one!
  • Conserve water where possible—“grey water systems,” rainwater harvesting, or even doing something as simple as turning off the tap while applying soap to your hands (every little bit helps).
  • Reduce waste—use composting in your garden. Return essential nutrients to the ground. Even apartment dwellers can compost! A quick website search can reveal how.
  • Reduce the plastic you purchase. (You can contact your local stores to ask them to offer less plastic packaged products.) 
  • Minimize your carbon footprintcheck out this link to discover how simple changes in daily choices can reduce your carbon footprint: 10 Simple Ways to Reduce Your Carbon Footprint
  • Avoid buying from or investing in companies that don’t support environmental initiatives.
  • Walk, where possible, or take a bike. The author of this article managed to not refill the fuel in her car for a month by just doing this.
  • If you own a home or are part of a housing cooperative, see if you can paint roofs and exterior walls with reflective white paint—white paint reflects sunlight back into space and cools your home, saving money.
  • Tell your politicians that nature is important to you—especially your local politicians! Make your voice heard.
  • Take a walk in nature and reconnect—you will realize the benefits and its beauty.
  • Take part in activities that promote healthier environments in your area, like invasive species removal with professionals, litter pick-ups, planting trees, and maybe even creating your own community activity that help make your local ecosystem better.


Copyright © New England Primate Conservancy 2023. You may freely use, copy and share these Learning Activities for educational purposes. 
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