Beavers and their dams: what effects do they have?

Hi everyone,

Today we're talking about beavers and their effects on the surrounding ecosystems and environments. 'Beaver' referres to two species in the genus Castor. They are found in North America, Europe and Asia and are the largest rodents in those places and the second largest rodents in the world. Beavers grow up to 80 cm long with a flat, paddle-shaped tail up to 45 cm. They have a small head, large incisor teeth and fur lined lips to avoid inhaling water while cutting and transporting branches underwater. They weigh 16-30kg and are nocturnal.

Beavers live in streams, rivers, marshes, ponds and lakes where they construct dams. These have earned them the title 'ecosystem engineers' but we'll talk about that later. The dams are constructed with branches, sticks and rocks. They create a calm pool with a higher water level on one side. Beavers make their homes (lodges) in these calm pools. Beaver dams are both have both positive and negative effects on the environment.

Probably the biggest problem with beaver dams is the flooding. The water that is held back by the dam has to go somewhere and it normally floods the surrounding landscape. This is where the name 'ecosystem engineers' comes from because they change the entire landscape by redirecting/expanding the rivers and streams and therefore drastically change the flora and fauna. This can cause severe damages to surrounding ecosystems and human infrastructure.

Beaver dams also interfere with migration of fish species such as salmon, as they block the rivers that these fish are trying to travel up/down. Also, methane producing microbes thrive in the sediment that forms around beaver dams. This is a big problem in regards to climate change. The water also has a severe lack of oxygen, causing many underwater plants die.

However, beaver dams have a lot of benefits. The flooding of the surrounding area creates wetlands which promote biodiversity. The beavers thin out trees while making their dams which prevents the domination by a single plant species and reduces the risk of forest fires. Different species of plants, animals and microorganisms thrive in the pools behind the dams. These pools also store carbon as the submerged wood decomposes a lot slower due to the lack of oxygen. The carbon stays locked in the wood for a long time leading to beaver meadows to be a large carbon store. The problem is that when the beavers leave the area or get killed, the dams eventually break and the wood is exposed to oxygen.

The dams reduce erosion, which is a big problem that waterways and coasts are facing at the moment. The dams also mean that sudden flooding is reduced. When floods of water come down a river, they can cause massive destruction but the beaver dams and surrounding wetland can catch the floods and lead to just a small slower increase of water further downstream.

We hope you found this post interesting. And who knows you may have beavers in your local area! In the UK, they have been reintroduced as a very cheap form of flood protection and water management.

Your Green World Blog Team💚

Sources:

https://www.britannica.com/animal/beaver

https://www.forestwildlife.org/how-do-beaver-dams-affect-the-environment/

https://www.science.org/content/article/what-role-do-beavers-play-climate-change

https://www.stir.ac.uk/news/2018/10/beavers-impact-on-biodiversity-revealed/

https://iopscience.iop.org/article/10.1088/1755-1315/201/1/012015/pdf

Images:

1: This image, owned by Michael Levine-Clark (on flickr.com) is liscensed under CC BY-NC-ND 2.0.
2: Beaver Dam in Winter, owned by Gerry Dincher (on flickr.com), is licensed under CC BY-SA 2.0.

3: This image, owned by Fred Moore (on flickr.com) is liscensed under CC BY-NC 2.0.

Comments

Overfishing- An Introduction

When writing the article on the Yangtze Finless Porpoise, I briefly touched on the topic of overfishing. Many of you have probably heard about it, and know it is a massive problem threatening our seas and their inhabitants. Overfishing is so destructive, it can kill all life in the ocean, and many of you might be part of it every day. So I read through many articles from international organisations, and they all say pretty much the same things. It's a highly complex topic, with so many things to say and do, so this is just an introduction to the broadest points. It's very interesting (and sad) but when you look into it further you realize there is actually a lot you can do! This is very important, especially for ocean lovers and seafood people. What is overfishing? By definition, overfishing is so intense fishing, people catch fish quicker than the stocks can reproduce. Leading to a massive decrease in stocks that can peak in the extinction of a s...

Photo Essay | dolphin spotting boat ride

Hi Everyone! Quite a while ago now, me and my family went on a dolphin spotting boat ride, and I've been meaning to share some photos for ages now! We saw so many dolphins very close up and we managed to get some good shots, although it can never be as magical as in person! All photos in this post were taken by me or my family. They were so close to the boat! This photo is stunning! It's under the water! Again - under the water! It was so hard to capture them jumping! This was the boat.... ...

Animals 36-40 in our '50 incredible animals' series

Hi, As you probably noticed, we took a break from this series, mostly due to having just too much to do. But we're back now with the last three posts. 36. The Pinocchio frog The Pinocchio frog can be found in the Foja Mountains in Indonesia. They mainly eat insects, although little is known about them. They are named because the males have a spike on their noses. They were only discovered in 2008, and this was completely by accident! It remained unnamed scientifically until over ten years later when it was given the name " Litoria pinocchio " . There is very little information about them but Wikipedia states that "the male Pinocchio frog inflates its nose when calling, and the nose decreases in size when the frog is calm and quiet," which I think is hilarious and so interesting! 37. Snub-nosed monkey Especially noticeable due to their curious looks, the snub-nosed monkeys can be found in the forests of central China and northern...

April Top Tips: ten tips for environmentally friendly travel

Hi Everyone! We haven't been very present on the blog again recently but we are back today with ten top tips for environmentally friendly travel. Most forms of travel over long distances (unless you are willing to put in a lot of physical effort) use fossil fuels and are generally not good for our planet. So today we will be giving you a few tips which although won't mean that your travel is 100% planet friendly, will be a good start to doing as much as you can. Your Green World Blog Team💚 1. Use trains and boats rather than planes where possible Planes are awful for the environment. They are, however, extremely practical and so easy to use, cheap...It's hard to avoid them! They are so quick too so you don't have to spend as much time travelling. However, they are really bad for the environment. For example, you could fly once to Edinburgh from Heathrow for the same carbon dioxide levels as driving to Edinburgh 336 times! 2. Fly...

Energy comparison: Hydroelectricity

Hello everyone, Welcome back to another energy comparison post. Today we're talking about hydroelectricity. This is basically just using the power of moving water for our own uses. This idea has been around for thousands of years. The ancient Greeks and Romans used watermills to grind grains for making bread. Watermills were used up until the Industrial Revolution. What is hydroelectricity? There are three types of hydroelectric power plants. Impoundment facilities are the most common. The water is stored in a pool or reservoir normally located at a higher elevation. The dam uses gates or valves to control the water flow. When there is demand for electricity, the water is released. It falls downwards and turns turbines that turn the kinetic energy of the water (movement energy) into electric energy. Diversion facilities don't have a dam. They channel the water towards the turbines using a system of canals. Pumped-storage facilities are...

Animals 11-15 in our '50 incredible animals' series

Hello, We have another five amazing animals for you today. Enjoy! 11. Dhole This is a dog species which looks rather like a red fox . They are difficult to put into any of the dog subfamilies. They aren't foxes, nor wolves, nor domestic dogs. Dholes are fast runners and live in packs of 5-12 individuals. Although sometimes, different packs will join forces to become a pack of 30 or more individuals! However, these super packs are broken up after a successful hunt. The different packs rarely attack each other as neighbouring packs are often closely related. Dhole packs live in burrows with multiple entrances. They can be found in eastern and southern Asia. They eat wild berries, insects and lizards and as a pack hunt deer, rodents and other wild mammals. Interestingly, unlike other dogs, they rarely kill by biting at the throat. They are also good swimmers! 12. Irrawaddy dolphin The Irrawaddy dolphin can be found in coastal areas of south a...

10 animals on the edge of extinction you didn't know about no. 9 - South Island takahē

Hello Today we’re talking about the South Island takahē, porphyrio hochstetteri . They are flightless birds, endemic to New Zealand. Takahē are brightly coloured and weigh 2.3-3.8 kg. They have red legs and a large red beak. Their feathers are coloured blue and green. They have wings, but these are only used during courtship or rivalry displays. They are territorial, with one family’s territory reaching anywhere from 4 ha to 100 ha (0,04-1km^2). Pairs will live in the same territory each year. They breed once a year and will raise 1-3 chicks (normally 2) each year. Both parents raise the chicks together. In the wild, takahē live in native grasslands and have a lifespan of 16-18 years. If snow covers the ground then they will move into nearby forests. They eat tussock grasses, sedges and sometimes rushes. But they are opportunists, so they will occasionally go for insects or even ducklings and...

Ozone layer

Hi everyone, What even is ozone? And the ozone layer? Where does the hole in the ozone layer come from and what does it mean? Is it dangerous? What can be done? Often the ozone-talk can be complicated and confusing, keeping an overview is hard and understanding all the problems always difficult. Let us break it down a bit for you: What is the ozone layer? We'll start with the basics: The ozone layer is part of the stratosphere, which is the second layer of the Earth's atmosphere, between 10 and 50 km above the Earth's surface and made up of protective gases. One of these protective gases is ozone. There is not much ozone in the atmosphere, only 0.3 molecule of ozone per 1 million molecules of air. This is because ozone is chemically unstable and only forms when ultra violet radiation (UV light) hits oxygen and breaks the bonds between the atoms. It fact it is so unstable that even when it has formed, it breaks down again relatively quickly. This leads to ozone turning back ...

Animals 41 - 45 in our '50 incredible animals' series

Hi everyone, 41. Ghost shark So first of all, this is a real animal and not a horror movie! Ghost sharks, often referred to as chimaeras, include around 50 species. They mostly live in the deep ocean and are seldom seen, hence the name. They can be found all over the world. Some species have a large range, for example, the rabbit fish which inhabits the entire northern Atlantic Ocean, or a small range, like the Galapagos Ghost shark which only lives in the waters around the Galapagos . Not much is known considering their population status however they are currently not considered threatened. It is assumed that they reproduce in the same way as most sharks. Not much else is known about ghost sharks. They are as mysterious as their name suggests! 42. Sea pig Again, this is a real animal! But it is not in any way like a pig (I have no idea why they called it a sea pig ). It is a type of sea cucumber, that lives in the ocean depths. Their bodies are fille...

How does plastic affect the environment?

Hello, I wanted to clarify exactly how plastic affects the environment. I hope this will explain. When plastic breaks, it releases toxic gasses that poison animals. Also, if plastic is swallowed it could cut or damage the inside of the animal. Many animals such as turtles and dolphins mistake the small plastic fragments for food. Even if the plastic is too small to cut into the insides of the animal or cause choking, too many micro plastics inside an animal will eventually block the digestive tracts and they will starve to death. Recent research proves that plastic has entered the human body. This is because plankton eats microplastics and small fish eat plankton. Bigger fish eat smaller fish and we eat the bigger fish. So inside us is plastic. Plastic also blocks waterways and sewers. This leads to the perfect breading grounds for disease carrying animals such as mosquitos. When plastic is burned it releases those toxic gas...

Green World

Search This Blog