Hi, I'm Jensen Morgan. We're going to talk about some great concepts in environmental science. Today's topic is biodiversity. So let's get started.
We're going to talk about the benefits of biodiversity, what ecosystem services are, and the potential sixth major extinction. Before we can even begin to discuss biodiversity, we need to define what an ecosystem is, our first key term for today, which is the living and nonliving components that interact in a given area.
With the definition of ecosystem under our belts, now let's look at what biodiversity means, our second key term, the number and relative abundance of species in a given area. The concept of biodiversity can also be extended to include the entirety of global biodiversity or number and relative abundance of species worldwide.
Biodiversity is important, because on a large scale, it supports and increases stability across ecosystems, because each species plays a different role in an ecosystem and all are interdependent on each other for the healthy functioning of the whole. A loss of species diversity would weaken us. The loss of a single species in an ecosystem could have unforeseen widespread consequences, including the loss of other species.
An example of such a scenario would be the extinction of coral reefs. Coral reefs worldwide are disappearing from global warming faster than forests are from deforestation. If they were to go completely extinct, it would have widespread effects.
Thousands of aquatic species make their homes in and around coral reef systems. Without them, those species will be threatened, entire ecosystems will be weakened, essentially creating a ripple effect of damages. The result will impact fisheries and reduce human economic and food source.
Again, biodiversity is key to maintaining ecosystem health. Ecosystems themselves provide many benefits to humans, which are called ecosystem services. There are four main categories of ecosystem services as follows.
Provisioning services, such as food, fiber, fuels, fresh water, and medicines. Then there are regulating services, such as climate regulation, water purification, and pollination. Cultural services, such as religious or spiritual value and use, recreation, educational use, and aesthetic value. And lastly, supporting services, such as nutrient cycling, soil formation, and production of energy from sunlight.
Different parts of ecosystems provide different types of services. An example of such a service would be what plant species provide through photosynthesis, oxygen. Without this service, the atmosphere's mixture of different gases would become imbalanced.
Humans require a certain mix of oxygen in the air to breathe and perform respiration. Without plants, there wouldn't be enough. The free oxygen plants produce also eventually gets changed into atmospheric ozone, which is necessary to protect humans from UV radiation. Plants also absorb carbon dioxide, which buffers against the greenhouse effect and global climate change.
Many scientists are considering the current era of human population growth to be the sixth major extinction, or the Holocene extinction. This era includes the last 12,000 years to the present. In that time, it is estimated that somewhere between 500,000 to one million species of birds, mammals, reptiles, amphibians, plants, and insects have gone extinct from over harvesting, habitat degradation, and pollution from human population growth and activities.
Current science estimates that 140,000 species per year are going extinct due to present human activities. By 2050, it is estimated that approximately 30% to 50% of human era species will have gone extinct. These numbers become even more impressive when you consider that the recovery of biodiversity from previous mass extinctions took millions of years.
Now, let's have a recap. We talked about the benefits and importance of biodiversity to ecosystem health, various ecosystem services humans use, and what scientists are calling the sixth major extinction, or the Holocene extinction, resulting from human activities.
Also, don't forget our key terms for today, ecosystem, the living and nonliving components that interact in a given area, and biodiversity, the number and relative abundance of species in a given area. Well, that's all for this tutorial. I look forward to next time. Bye.
(00:00 - 00:20) Introduction
(00:21 - 00:35) Ecosystem
(00:36 - 01:55) Biodiversity
(01:56 - 02:38) Ecosystem Services
(02:39 - 03:16) Plant's Services
(03:17 - 04:10) Sixth Major Extinction
(04:11 - 04:45) Recap
The number and relative abundance of a species in a given area.
The living and nonliving components that interact in a given area.