Hi I am here to talk to you today about biogeography, and the lesson on biogeography, which is the distribution of the earth's major six major biomes. Biomes are basically large, generalized ecosystems they include both living communities of plants and animals and their non-living environment as well. A rock, soil anything that basically is in the physical environment that is not living. So you're going to want to make sure that you're able to, that you can distinguish between what is biotic and what is biotic, what is living and non-living. Sounds pretty straightforward, but I just want to kind of give you a heads up that something that you might need to know. So we show you first a map of the six major biomes. Some of those you may recognize, such as forests, and we're going to return to that later in the lesson. Before we get into biomes, we talk a little bit about a few other topics beginning with energy flows. And this includes something that you might have learned about maybe in elementary or junior high science: photosynthesis and respiration. What you're going to want to know is what is consumed in photosynthesis and then what is what the output is and then what is created. What is the product? What has the plant gained from photosynthesis? So you will basically want to know all sides of that equation. The same goes for respiration. What is taken in, what is put out, what is gained, what is lost. So make sure you understand both of those equations well. You're also going to want to understand net primary productivity. And we show some nice maps of different rates of, or net primary productivity at different times of the year. Be sure you can understand how that varies over time and space. It's not constant some communities are just generally overall more productive but then there's times of the year when other communities peak and you want to understand when that is, why that is. So be sure to take a look at those maps. And then trophic levels. This is the the pyramid that we show of Trophic levels. You're going to want to know what each of those levels mean, and why it's a pyramid. Why is the base wide- that is the largest number- all the way up to the smallest number. So make sure you understand those different levels and then why it is the pyramid shape; why largest on the bottom, smallest at the top, what those numbers mean. Our next topic is something that's little bit more difficult for students generally, and we what we do is point you to some pages in the textbook to read this will really supplement your knowledge of succession. So we talk about the two general forms primary or secondary, the two basic divisions, and then we go into some specific types. You know in those specific types we have like a little box or a little table and we give some examples, but I think you should also be able to come up with some examples on your own because on the exam [quiz] we might talk about, say for example, a residential developer comes in and clears land because he's going to make a subdivision. Well then something happens the economy tanks he goes out of business, he was bankrupt, and no one picks up the land, and it returns to a central vegetative state. What kind of succession is that based on what's happened with the series of events that went on there? So be sure you understand those examples and then are able to come up with some of your own. The next I think is dispersal mechanisms. This is that good or the lab notes at the end of your lesson, and as you know those are not required reading, however this topic, dispersal mechanisms, is covered in the lab notes. That's for students who are going to go on and take the geography 206 lab, but you might be able to use this If you want to see some, or to learn a little bit more about dispersal mechanisms and the different ways that plants are able to disperse and reproduce in their ecosystem. And then limiting factors, biotic and abiotic limiting factors. Again, be sure you want to understand each of those. So then after that we're going to return to biomes and their distributions. So what defines biomes? There are three different, general things and you should know what those things are. Then we talk about the limiting factors biomes; we have climate, soil, and topography. It might be pretty obvious to you how climate can limit or determine a biome. This is a big one, lack of rainfall and we see desert vegetation. Or maybe of abundance of rainfall and humid climate and we see rain forest or forest vegetation. So understand how climate works and determines what vegetation is there. And why it's a limiting factor. And then soil, soil fertility and type of soil, and then topography and how the presence or absence of vegetation may be determined or certain vegetative forms may be determined by things such as slope and aspect. This is big in the mid-latitudes as you move away from the tropics, the way the slope is facing, whether or not trees might grow there. From there we look at three different case studies. We look at the African continent and how the migration of the Intertropical Convergence Zone determines the different biomes there. Remember if we go back to global circulation, that band of rain, at the equatorial, at the Intertropical Convergence Zone, and how that migrates north and south throughout the year, basically carrying rainfall a little bit north and a little bit south into the fringe areas, before it grades to desert. So make sure you understand that case study, and why, or how global circulation and atmospheric circulation plays a role in the biomes on the African continent. Then we talk about the United States and really neat transect of decreasing precipitation from east to west, to the east where forest is the dominant vegetation to west where it basically grades to short grass prairie and tall grass prairie. And why there is decreasing rainfall. Why does moisture not reach the continental interior in the United States? Whereas the east is very moist and has enough precipitation to support forest vegetation. So make sure you understand that. From there our last case study is Michigan. And we talk about the florist tension zone of Michigan, which is neat, one of the faculty members in our department has done a lot of research on this. It's basically the change in the dominant forest type as you drive north through the Lower Peninsula of Michigan and why that takes place. So again understand that, and it isn't just temperature. I mean we obviously know that it's quite cold in the Upper Peninsula, but something else is at play there. So make sure you take a look. And our last topic is deforestation. We talk quite a bit about the value of forests...actually that's not our last topic, we have one more after that, but deforestation, we talk a lot about the value of forests, the different values. So make sure if we gave you an example, maybe a forest being logged to make paper bags, a managed pine plantation, you could say what value of forests that was serving. Or maybe a habitat for certain animal, what value is that? Be sure that you're able to give examples of each of those values. We talk a little bit about what forests are currently undergoing the heaviest deforestation. which is in our tropical areas, but also historically our temperate forests have been some of the most degraded in the world. We have very few old growth forests that remain in the United States. So it's not like deforestation is something that's just happened now, or just over the past the past few decades. Our forests here in the United States, and also in Europe, have been heavily logged over. So that is something to keep in mind. We talk a little bit about logging methods used in deforestation or logging methods used in managing silvaculture, managing forestry. So make sure if we talk about maybe a logging company practicing a certain method, and we don't give you the name, but we say they did this, this, and this. What method is that that they are using in their forestry practices? Make sure you understand that. And definition of deforestation, which seems really simple! There's quite a few different definitions depending on who you are and what your outlook is that you could use for deforestation, but in this class we kind of use when trees cut down outnumber new growth then it's deforestation. So what happens then? If you plant a tree for a tree, well then, deforestation isn't really taking place? It actually gets a lot more complicated than that, but simply by definition that is because that's the definition of deforestation we're using. We don't get into it as a class but I would say our forests are not created equal. But again, deforestation takes place when the number of trees cut down doesn't out number new growth or trees planted. So our last topic, Well actually that's it! That is our last topic. All right, I think I've covered everything that I can think of that you would need to know for the exam [quiz]. Just remember to understand like I said each of those case studies, deforestation, the value of trees, the things we covered in the beginning trophic levels, succession, dispersal mechanisms, biomes and their distributions. Yeah I think I've pretty much covered it. So hopefully you are ready to take the exam [quiz] when it comes time.