ah the old Von tunin model or as students are likely to call it the Von I don't know what the crap this is talking about model but you got to know it and I'm here to explain it up real nice for you so if you're ready to get them brain cows milk let's get to it okay now before I lay out the basics of this model it might be helpful for you to have some context as to why this dang thing is so important so recall that this unit is all about agriculture and for the last few videos we've been discussing the various factors that explain why certain kinds of farming occurs where it does in the world or if you're Saucy you could say that we've been considering the spatial arrangement of Agriculture throughout the and as it turns out this question about why certain agricultural practices occurred in different places got an old Prussian farmer and geographer all kinds of exciting his name was Johan Hinrich Von tunin and in the 19th century he developed a model that explains the spatial arrangement of Agriculture and it's pretty tasty so the basic idea of the Von tunin model goes like this the distance to the market determines the kind of Agriculture that will be practiced in a given location and the key decision-making factor is the perishability of the product and the cost of Transportation now ultimately Von tunin was trying to solve the puzzle of the farmers's economic relationship with the land and although Von tunin died almost 200 years ago he could hear the Ardent desires of future AP Human Geography students crying out yes but is there a visual representation of this model and by the hammer of Thor there is and we can see it in the form of five concentric circles before I show it to you let me just mention that if you need help getting an A in your class and a five on your exam in May then you might want to check out my AP Human Geography himly review gu it's got whole unit review videos that you're not going to see here on YouTube note guys to follow along practice questions practice I exams and answer keys for all of it so if that's something you're into check out the link in the description okay so at the center of this model is a market where agricultural goods are sold known as the central business district or CBD which we talked about in the last video when we talked about bid rent Theory and then the first string is where intensive farming and dairy farming occur Von tuna observed that fruits and vegetables and milk are perishable so they need to be transported to the market quickly so they're going to pay more for land so that they can pay less for transportation that higher cost is worth it to the farmer because those goods tend to fetch a higher price at the market then the second range is where forests and Timber farming occur see wood is bulky and heavy and so being closer to the CBD means Transportation costs are lower and that would be important because during Von tonin's time wood was the primary building materials for houses most of which would be close to the CBD and then the third ring is where grains and cereal crops are located because these are not as heavy as wood or milk to transport these farmers can afford to transport their crops farther distances in order to maximize their profit and then the fourth ring is where ranching and livestock farming occurs ranching requires large tracks of land for grazing so the least expensive land furthest from the CBD is more desirable okay as lovely as that model is here's where I tell you that it like any other model has serious limitations in its ability to explain the spatial arrangement of Agriculture the reason it has limitations is because Von tuna developed this model as if he were a laboratory scientist see in a laboratory a scientist's main goal is to remove all the real world variables that would mess up the experiment and its explanatory power and so in developing this model Von tun and made several assumptions in order to keep the explanatory power of this model nice and tidy so the model first assumption is that any given place has access to only one market or CBD but in reality especially in the last 100 years Farmers have access to a metric butload of potential markets okay the second assumption is that the market is located in a single self-sufficient state with no outside influence and maybe an isolated State could have existed 10,000 years ago but even in Von tuna's time there were no states that were completely free from outside influence from other states and today with the rapid pace of globalization every dang State on the planet is Tangled Up in a global economic political and social hugfest and then third the model assumes that the land is isotropic or completely flat and featureless in that case yeah farmers only going to have to consider the cost of transportation to the CBD when deciding where to locate but here in reality there are all kinds of hills and mountains and rivers Etc that affect how goods are transported to the market and finally this model assumes that farmers have only one means of transportation to the market namely an ox pulling a cart and as much as we may long for a world in which all of our stuff was delivered by Ox well you know that's not how it is no we've got trains and ships and airplanes that can affect how quickly agriculture Cal Goods can be transported to various markets and then the final limitation I'll mention here is that Von tun's model does not sufficiently account for the spatial arrangement of specialty farm for example commercial farmers in central Mexico's tropical climate specialize in avocados and ship them all over the world so there is not so much Transportation cost or distance from the CBD that determines what they grow but instead their climate and probably the natural question forming in your mind is this if the assumptions of this model don't square with real world conditions then why do we have to learn it well despite its obvious limitations the model actually does a pretty good job of predicting where various kinds of Agriculture will take place it's not perfect but it's pretty good and just let me show you and in order to do that let me tell you that the last thing you need to be able to do is understand how Von tonin's model can be applied at various scales so let's consider the United States and see if it squares with Von tunan model we'll assume that New York City is the lone CBD and that the land is flat and featureless in that case here's what Von tuna's model would predict Dairy farming here cotton and tobacco here corn soybeans and wheat here cattle and sheep ranching here and Forest and Timber farming Here and Now compare it to the actual arrangement of us fing and you can see that the model does a fair job of predicting the spatial Arrangement now you have to remember that the folks who founded and built the United States didn't have a copy of Von tuna's book in their hands and decide oh this is how we're going to arrange our farming regions no as the country developed over time Farmers economic relationships to the land determined where they would farm and this was the result so high five Devon tunin for getting it pretty dang right even when Global conditions have changed so profoundly since this time and finally I should mention that Von tun's model is pretty dang accurate in the 21st century when it comes to predicting where farmers markets and community supported agricultural outfits are located in both cases goods are produced close to the market so they can sell them quickly and not spoil Okay click here to keep reviewing other topics in unit 5 and click here to get your hands on my AP Human Geography him review guide which is everything you need to get an A in your class and a five on your exam in May it's the fastest way to study and I think you're going to like I appreciate you coming around and I'll catch you on the flipflop I'm lout