Understanding the Importance of Biodiversity

Hello everyone, this presentation covers IBESS topic 3.1, an introduction to biodiversity, under the main topic 3, biodiversity and conservation. You should have already watched this TED-Ed uTip clip on biodiversity. Its underlying message is that each and every species is connected and important in maintaining the biodiversity and health of Earth. The IB significant ideas of topic 3.1 are 1. Biodiversity can be identified in a variety of forms including species diversity, habitat diversity, and genetic diversity. 2. The ability to both understand and quantify biodiversity is important to conservation efforts. You must be able to distinguish between biodiversity, species diversity, genetic diversity, and habitat diversity. So, I will go into more details on these items. Biodiversity as defined by the Biodiversity Convention of 1992 is the variability amongst living organisms from all sources and ecological complexes of which they are a part. This includes diversity within species, between species, and of ecosystems. Be able to recognize the use of biodiversity with slightly different nuances and definition. For example, Biodiversity is a measure of the biological richness of an area, taking into account the number of species, community complexity, and genetic variation within populations, or the amount of biological or living diversity per unit area. This includes concepts of species diversity, habitat diversity, and genetic diversity. Or, you might see biodiversity as a measure of the species richness. This is a product of the number of species and their relative abundance. It is important to recognize that each species and process is key to the overall function of Earth. Generally speaking, diversity results in the stability of a biome or ecosystem. Biodiversity is nature's insurance policy against change, because a highly diverse system is often both resistant and resilient to change. Biodiversity is ultimately the source of all natural capital for human use. Biodiversity enables the recycling and purification of chemical materials. And finally, biodiversity is the end result of millions of years of evolution and therefore it is irreplaceable. As I've mentioned, biodiversity is the overall term for three but interrelated types of diversity. genetic diversity, species diversity, and habitat diversity. Let's define these three terms. Genetic diversity. Genetic diversity is the total number of genetic characteristics present in the gene pool of a population of a specific species. The larger the population, the more likely you are to have different genes present, resulting in greater genetic diversity. Genetic diversity. or variability is important to the survival of a species. Higher genetic diversity yields higher chance of a species surviving. The cheetah is an example of a species with low genetic diversity resulting in poor sperm quality. Thus, breeding and survivorship is difficult for cheetahs, especially since only about 5 percent of cheetahs survive to adulthood. Species diversity. Species diversity is the number of species or organisms per unit area found in different habitats or biomes of the planet. The image on this slide you can see is an aquatic system with high species diversity. So just how many different species are there? In 2011 a published article estimated that there are about 8.7 million species on Earth. with about 6.7 on land and 2.2 million on the oceans. However, some estimates of the number of species on Earth stretch to 100 million species. Note that only about 1.2 million of all these species has been formally described. Habitat diversity. Habitat diversity is the range of different habitats per unit area in a particular ecosystem or biome. In El Refugio in Eastern Bolivia, shown in this slide, you can see that there is a big range of habitats, including grasslands, marshes, seasonally flooded areas with different flooding depths, rivers, lakes, riparian zones, and more. With all of these different habitats, how many niches do you think there are for different animals? Do you think there is a link between habitat diversity and species diversity or genetic diversity? And why might there be a link? You should be able to explain why greater habitat diversity leads to greater species and genetic diversity. Why might having a variety of forests, deserts, grasslands, lakes, oceans, coral reefs, wetlands, or other biological communities play a role in species and genetic diversity. Here is a hint. Consider all the potential niches that these different habitats provide. First of all, consider how habitat diversity changes over successional time. Think back to our discussion on primary and secondary succession. Recall that over a successional time, there is an increase in plant species. resulting in habitats and niches for animal species. As the plant species increase, so do the animal species. Now consider this graph where species richness is identified on the y-axis. Species richness being the number of different species in an ecosystem or biome. Notice how species richness increases over successional time. Eventually, the number of species tapers off because once a climax community is attained, there are no longer changes in species numbers and the species reaches an equilibrium. Remember that diversity increases as habitats become more complex during succession. With climax species, there are more niches that support more different species with varying roles in the ecosystem. An environment that supports a mixture of species from different, successional stages will be more diverse than an environment that only supports species from early or late successional stages. Consider this example. Do you see different successional stages in this image, providing different and diverse habitats and niches for different animals? Climax forests or forests with both Canopies and floor layers have greater species diversity because of the number of different niches that support species having varying roles in the greater ecosystem. Additionally, over successional time, even the soil changes, supporting a greater number of decomposer species. Switching themes slightly, consider this graph in which scientists compared species richness with different sized islands in the Mediterranean Sea. As the area of the island increases, so does the number of species. If there is a greater area, or a bigger island in this case, there is a higher probability for different habitats, thus a greater likelihood of different niches for different species. Locations with mixtures of habitats such as this one with wet and dry regions as well as early and late succession will have greater diversity than an area with fewer habit types of habitats more habitats mean more niches which increases local diversity regions with changes in altitude also have increased diversity for example in this example of the sierra nevada vegetation zones you see woodlands at the base and subalpine forest nearer to the summit. These varying habitats support different niches, thus increasing local diversity. Changes in both temperature and rainfall due to the changes in altitude result in dramatically different habitats over short distances. The varying climates support different types of species, thus increasing local diversity. increasing local diversity. Even human manipulation of landscape can support increased diversity by planting late successional species and early successional species. This type of agriculture is seen in this slide is referred to as polyculture. We've been talking about how habitat diversity increases species diversity. Be aware that the spread of individuals between species is more important than the total number of individuals in a habitat. Let me explain. Species diversity in communities is a product of two variables. The number of species or richness and their relative proportions, evenness. So when we are considering richness we are looking at the number of species but when we are looking at evenness we are looking at the number of organisms within each species. Are there enough organisms within a population to reproduce and maintain the species? Look at the image, where there are more species on the right than on the left, thus resulting in higher richness and higher diversity. When we are considering an even representation of species, as the one here on the right, where you have two of every species versus four of one species and only one. one of each of the other species, there is higher evenness and thus higher diversity. High species diversity is a combination of both richness and evenness. So, which of these two communities has more diversity? Explain your thinking with reference to a number of different species, the richness, and relative proportions, the evenness. While both communities have four species of trees, the top community has more trees of each species, while the lower image is dominated by one species. Thus, the top image has higher evenness and therefore more diversity. To recap, species diversity, or D, is a product of both richness and evenness. So how do we quantify these measurements? Environmentalists use the Simpson Diversity Index. The Simpson Diversity Index, or D, takes into account both the number of species and their relative proportions. To utilize this particular formula, data is collected as percent frequency of each species, and then the index is calculated. The Simpson Diversity Index can also be calculated when the numbers of individuals are counted for each specific species. In this case, again, the calculation accounts for both the number of species and their relative proportions. We will do more examples of calculations of the Simpson Diversity Index in class. However, let's take a look at... this practice problem from Bioninja.com. In sample 1, there are three species observed, A, B, and C, while in sample 2, there are only two species observed, A and D. Initially, one might think due to the higher richness, more species observed in sample 1, it is more diverse. However, after completing the calculations, notice, how the calculations are done. Again, we'll do more of these in class. But after completing the calculations, we see that sample 1 actually has a lower diversity of 1.87 than sample 2, 2.3. This is due to the fact that of the lower evenness in sample 1. Notice how there's only one of species B and species C. While in sample 2, there are four of each of the species there represented. This lower evenness drives down the diversity index. Okay, so what other information might D values tell us? High values of D might suggest a stable and ancient site, which may then be targeted for conservation. A low value of D could suggest an effect of human impact, such as pollution, recent... recent colonization or agricultural management, especially when comparing the value to a similar site that has a higher deed. Quantification of biodiversity is important to conservation efforts, so that areas of high biodiversity can be identified, explored, and appropriate conservation put into place where possible. However, determining what areas should be protected under conservation mandates can be complicated. For example, consider a desert that has a low diversity compared to the tropical rainforest. But there might be specific species that need protection in the desert. Or, for ethical or aesthetic reasons, people might want to enact conservation of the desert. So how did we get all this amazing diversity on Earth? We will study this in more detail in Topic 3.2. But for now, realize that this diversity has taken millions of years to develop through the process of natural selection. Factors contributing to natural selection include genetic variations within a population, production of large numbers of offspring and limited resources. Individuals most suited to gain resources survive and produce at higher rates, passing on their traits to future generations. So why is biodiversity so important? It is a sign of stability, and it is essentially, therefore, Earth's insurance policy against change. Biodiversity is the source of all-natural capital for human use. It allows for chemical materials to be recycled and purified, and it is the end result of millions of years of evolution, and thus it is irreplaceable. As I mentioned, diverse ecosystems are more stable and more healthy. They are more resistant to damage from factors like climate change and spread of disease. Biodiversity is also useful to us as humans. It provides us with recreation, food, goods, and medicine. Ecological services are also provided to humans as a result of biodiversity. These include the flow of material and energy in the biosphere, photosynthesis, pollination, soil formation and maintenance, nutrient cycling, moderation of weather extremes, and purification of... air and water. Did you know that fuel and food and ecosystems and species and fiber and lumber and paper and more, including 90% of all our food crops and medicines and our antibiotics are all dependent on having diversity? So yes, biodiversity is important. The areas marked in red on this slide are what we call biodiversity hotspots. A hotspot is a region with a high level of biodiversity that is under threat from human activities and is thus in urgent need of protection. By measuring diversity, we can focus the resources of conservation in the areas of greatest need. Hotspots are areas in need of emergency conservation attention. They are especially rich in endemic plant and animal species, endemic meaning that these species are found nowhere else in the world. They cover only about 2.3 percent of world land surface, but support 52 percent of plant species and 36 percent of terrestrial vertebrates. They are mostly tropical forests, but other biomes as well. There are 17 mega diversity countries that hold two-thirds of all species. The top three are Brazil, Indonesia, and Colombia. 70% of habitats in hotspot areas have already been lost. It is important to note that there are 1.1 billion people living in poverty near these hotspot areas. Thus, only 1% of parks in lower economically developed countries receive protection. Currently, there are about 1,100 parks greater than 10 km2 in 120. Countries measuring biodiversity can help to direct funds for conservation in areas of greatest need to recap this entire presentation Biodiversity can be identified in a variety of forms including genetic species and habitat diversity habitat diversity influences species and genetic diversity by providing niches for different species offering a unique roles in the greater ecosystem. Habitat diversity is observed when there is a mixture of habitats, such as varying phases of succession or having different characteristics like wet and dry habitats, and through elevation and climate differences. Quantification of biodiversity, such as the Simpson Diversity Index, is important to conservation efforts so that areas of high biodiversity may be identified, explored, and appropriate conservation put into place where possible. Quantification of biodiversity can also be used to assess changes in biodiversity over time due to human impact. This ends the movie for IBESS Topic 3.1, An Introduction to Biodiversity. The slides are adapted from William Green's presentation on the site from the Amazing World of Mr. Science with Mr. Green at this URL. The Amazing World of Science is licensed under a Creative Commons Attribution International license. Additional insight was obtained from Mr. Dave Hoover's movie presentations at Hoover's YouTube channel. Both of these sites provide additional resources for study and learning. Another resource... for you is your IBESS textbook, whether in hardback form or online, such as Cognity. Thank you for listening.

The IB significant ideas of topic 3.1 are 1. Biodiversity can be identified in a variety of forms including species diversity, habitat diversity, and genetic diversity. 2. The ability to both understand and quantify biodiversity is important to conservation efforts. You must be able to distinguish between biodiversity, species diversity, genetic diversity, and habitat diversity.

So, I will go into more details on these items. Biodiversity as defined by the Biodiversity Convention of 1992 is the variability amongst living organisms from all sources and ecological complexes of which they are a part. This includes diversity within species, between species, and of ecosystems.

Be able to recognize the use of biodiversity with slightly different nuances and definition. For example, Biodiversity is a measure of the biological richness of an area, taking into account the number of species, community complexity, and genetic variation within populations, or the amount of biological or living diversity per unit area. This includes concepts of species diversity, habitat diversity, and genetic diversity.

Or, you might see biodiversity as a measure of the species richness. This is a product of the number of species and their relative abundance. It is important to recognize that each species and process is key to the overall function of Earth. Generally speaking, diversity results in the stability of a biome or ecosystem. Biodiversity is nature's insurance policy against change, because a highly diverse system is often both resistant and resilient to change.

Biodiversity is ultimately the source of all natural capital for human use. Biodiversity enables the recycling and purification of chemical materials. And finally, biodiversity is the end result of millions of years of evolution and therefore it is irreplaceable. As I've mentioned, biodiversity is the overall term for three but interrelated types of diversity. genetic diversity, species diversity, and habitat diversity.

Let's define these three terms. Genetic diversity. Genetic diversity is the total number of genetic characteristics present in the gene pool of a population of a specific species. The larger the population, the more likely you are to have different genes present, resulting in greater genetic diversity. Genetic diversity.

or variability is important to the survival of a species. Higher genetic diversity yields higher chance of a species surviving. The cheetah is an example of a species with low genetic diversity resulting in poor sperm quality. Thus, breeding and survivorship is difficult for cheetahs, especially since only about 5 percent of cheetahs survive to adulthood.

Species diversity. Species diversity is the number of species or organisms per unit area found in different habitats or biomes of the planet. The image on this slide you can see is an aquatic system with high species diversity.

So just how many different species are there? In 2011 a published article estimated that there are about 8.7 million species on Earth. with about 6.7 on land and 2.2 million on the oceans.

However, some estimates of the number of species on Earth stretch to 100 million species. Note that only about 1.2 million of all these species has been formally described. Habitat diversity. Habitat diversity is the range of different habitats per unit area in a particular ecosystem or biome.

In El Refugio in Eastern Bolivia, shown in this slide, you can see that there is a big range of habitats, including grasslands, marshes, seasonally flooded areas with different flooding depths, rivers, lakes, riparian zones, and more. With all of these different habitats, how many niches do you think there are for different animals? Do you think there is a link between habitat diversity and species diversity or genetic diversity?

And why might there be a link? You should be able to explain why greater habitat diversity leads to greater species and genetic diversity. Why might having a variety of forests, deserts, grasslands, lakes, oceans, coral reefs, wetlands, or other biological communities play a role in species and genetic diversity.

Here is a hint. Consider all the potential niches that these different habitats provide. First of all, consider how habitat diversity changes over successional time.

Think back to our discussion on primary and secondary succession. Recall that over a successional time, there is an increase in plant species. resulting in habitats and niches for animal species. As the plant species increase, so do the animal species. Now consider this graph where species richness is identified on the y-axis.

Species richness being the number of different species in an ecosystem or biome. Notice how species richness increases over successional time. Eventually, the number of species tapers off because once a climax community is attained, there are no longer changes in species numbers and the species reaches an equilibrium.

Remember that diversity increases as habitats become more complex during succession. With climax species, there are more niches that support more different species with varying roles in the ecosystem. An environment that supports a mixture of species from different, successional stages will be more diverse than an environment that only supports species from early or late successional stages. Consider this example.

Do you see different successional stages in this image, providing different and diverse habitats and niches for different animals? Climax forests or forests with both Canopies and floor layers have greater species diversity because of the number of different niches that support species having varying roles in the greater ecosystem. Additionally, over successional time, even the soil changes, supporting a greater number of decomposer species.

Switching themes slightly, consider this graph in which scientists compared species richness with different sized islands in the Mediterranean Sea. As the area of the island increases, so does the number of species. If there is a greater area, or a bigger island in this case, there is a higher probability for different habitats, thus a greater likelihood of different niches for different species. Locations with mixtures of habitats such as this one with wet and dry regions as well as early and late succession will have greater diversity than an area with fewer habit types of habitats more habitats mean more niches which increases local diversity regions with changes in altitude also have increased diversity for example in this example of the sierra nevada vegetation zones you see woodlands at the base and subalpine forest nearer to the summit. These varying habitats support different niches, thus increasing local diversity.

Changes in both temperature and rainfall due to the changes in altitude result in dramatically different habitats over short distances. The varying climates support different types of species, thus increasing local diversity. increasing local diversity. Even human manipulation of landscape can support increased diversity by planting late successional species and early successional species.

This type of agriculture is seen in this slide is referred to as polyculture. We've been talking about how habitat diversity increases species diversity. Be aware that the spread of individuals between species is more important than the total number of individuals in a habitat. Let me explain.

Species diversity in communities is a product of two variables. The number of species or richness and their relative proportions, evenness. So when we are considering richness we are looking at the number of species but when we are looking at evenness we are looking at the number of organisms within each species.

Are there enough organisms within a population to reproduce and maintain the species? Look at the image, where there are more species on the right than on the left, thus resulting in higher richness and higher diversity. When we are considering an even representation of species, as the one here on the right, where you have two of every species versus four of one species and only one. one of each of the other species, there is higher evenness and thus higher diversity.

High species diversity is a combination of both richness and evenness. So, which of these two communities has more diversity? Explain your thinking with reference to a number of different species, the richness, and relative proportions, the evenness. While both communities have four species of trees, the top community has more trees of each species, while the lower image is dominated by one species.

Thus, the top image has higher evenness and therefore more diversity. To recap, species diversity, or D, is a product of both richness and evenness. So how do we quantify these measurements?

Environmentalists use the Simpson Diversity Index. The Simpson Diversity Index, or D, takes into account both the number of species and their relative proportions. To utilize this particular formula, data is collected as percent frequency of each species, and then the index is calculated.

The Simpson Diversity Index can also be calculated when the numbers of individuals are counted for each specific species. In this case, again, the calculation accounts for both the number of species and their relative proportions. We will do more examples of calculations of the Simpson Diversity Index in class. However, let's take a look at...

this practice problem from Bioninja.com. In sample 1, there are three species observed, A, B, and C, while in sample 2, there are only two species observed, A and D. Initially, one might think due to the higher richness, more species observed in sample 1, it is more diverse. However, after completing the calculations, notice, how the calculations are done.

Again, we'll do more of these in class. But after completing the calculations, we see that sample 1 actually has a lower diversity of 1.87 than sample 2, 2.3. This is due to the fact that of the lower evenness in sample 1. Notice how there's only one of species B and species C.

While in sample 2, there are four of each of the species there represented. This lower evenness drives down the diversity index. Okay, so what other information might D values tell us?

High values of D might suggest a stable and ancient site, which may then be targeted for conservation. A low value of D could suggest an effect of human impact, such as pollution, recent... recent colonization or agricultural management, especially when comparing the value to a similar site that has a higher deed.

Quantification of biodiversity is important to conservation efforts, so that areas of high biodiversity can be identified, explored, and appropriate conservation put into place where possible. However, determining what areas should be protected under conservation mandates can be complicated. For example, consider a desert that has a low diversity compared to the tropical rainforest.

But there might be specific species that need protection in the desert. Or, for ethical or aesthetic reasons, people might want to enact conservation of the desert. So how did we get all this amazing diversity on Earth?

We will study this in more detail in Topic 3.2. But for now, realize that this diversity has taken millions of years to develop through the process of natural selection. Factors contributing to natural selection include genetic variations within a population, production of large numbers of offspring and limited resources.

Individuals most suited to gain resources survive and produce at higher rates, passing on their traits to future generations. So why is biodiversity so important? It is a sign of stability, and it is essentially, therefore, Earth's insurance policy against change. Biodiversity is the source of all-natural capital for human use.

It allows for chemical materials to be recycled and purified, and it is the end result of millions of years of evolution, and thus it is irreplaceable. As I mentioned, diverse ecosystems are more stable and more healthy. They are more resistant to damage from factors like climate change and spread of disease. Biodiversity is also useful to us as humans. It provides us with recreation, food, goods, and medicine.

Ecological services are also provided to humans as a result of biodiversity. These include the flow of material and energy in the biosphere, photosynthesis, pollination, soil formation and maintenance, nutrient cycling, moderation of weather extremes, and purification of... air and water.

Did you know that fuel and food and ecosystems and species and fiber and lumber and paper and more, including 90% of all our food crops and medicines and our antibiotics are all dependent on having diversity? So yes, biodiversity is important. The areas marked in red on this slide are what we call biodiversity hotspots.

A hotspot is a region with a high level of biodiversity that is under threat from human activities and is thus in urgent need of protection. By measuring diversity, we can focus the resources of conservation in the areas of greatest need. Hotspots are areas in need of emergency conservation attention.

They are especially rich in endemic plant and animal species, endemic meaning that these species are found nowhere else in the world. They cover only about 2.3 percent of world land surface, but support 52 percent of plant species and 36 percent of terrestrial vertebrates. They are mostly tropical forests, but other biomes as well.

There are 17 mega diversity countries that hold two-thirds of all species. The top three are Brazil, Indonesia, and Colombia. 70% of habitats in hotspot areas have already been lost.

It is important to note that there are 1.1 billion people living in poverty near these hotspot areas. Thus, only 1% of parks in lower economically developed countries receive protection. Currently, there are about 1,100 parks greater than 10 km2 in 120. Countries measuring biodiversity can help to direct funds for conservation in areas of greatest need to recap this entire presentation Biodiversity can be identified in a variety of forms including genetic species and habitat diversity habitat diversity influences species and genetic diversity by providing niches for different species offering a unique roles in the greater ecosystem.

Habitat diversity is observed when there is a mixture of habitats, such as varying phases of succession or having different characteristics like wet and dry habitats, and through elevation and climate differences. Quantification of biodiversity, such as the Simpson Diversity Index, is important to conservation efforts so that areas of high biodiversity may be identified, explored, and appropriate conservation put into place where possible. Quantification of biodiversity can also be used to assess changes in biodiversity over time due to human impact. This ends the movie for IBESS Topic 3.1, An Introduction to Biodiversity.

The slides are adapted from William Green's presentation on the site from the Amazing World of Mr. Science with Mr. Green at this URL. The Amazing World of Science is licensed under a Creative Commons Attribution International license. Additional insight was obtained from Mr. Dave Hoover's movie presentations at Hoover's YouTube channel.

Both of these sites provide additional resources for study and learning. Another resource... for you is your IBESS textbook, whether in hardback form or online, such as Cognity.

Thank you for listening.

Transcript for:Understanding the Importance of Biodiversity

Transcript for:
Understanding the Importance of Biodiversity