[MUSIC] Today we are going to talk about forests. Forests are one of the most important ecosystems for humans. We are going to talk about forest dynamics, forest functioning, and also forest management, and we will see some ways of studying this forests. So here in the first slide, you can see a map. In this map, you can observe the different biomes of the Earth. A biome is a big unit of classification of the landscapes of the biosphere. And here you have a green circle in all the volumes that are considered forest. You can see that they are much more than a half of the biomes in this map. Completely a third of the terrestrial emerged surface are forests. So if we define the forest, we can define it many ways. But here, you can find that definition by the FAO, the Food and Agriculture Organization of the United Nations. And define it as the land spanning more than 0.5 hectares and with trees of minimum 5 meters and a canopy cover of more than 10%. So here when you think about forest probably, many types of forests can come into your head. I have selected some pictures to try to illustrate different types of forests. Here you have a picture of a tropical forest it could be in Australia or maybe in Perum. Here you can see a boreal forest mainly with conifers and it could be a Taiga from Russia or maybe from Canada. The next one is a temperate forest. This is a forest of Fagus sylvatica, and this picture is taken in the Mediterranean basin concretely. So now that I am talking about temperate forests, I would like to introduce you Dr. Emma Lucy Braun. One of her major contributions to science is the book Deciduous Forests of Eastern North America. And she was the first woman to be president of the Ecological Society of America. Well, now I'm going to present you the oldest known living non-clonal organism on Earth, which is a tree. Completely the species, that Pinus longaeva, in English it's also called the great basin bristlecone pine, and it's in the US. So some of the individuals of the species has been estimated to have 5,000 years. And so for this reason, this is considered the oldest known living, non-clonal organism on Earth. But what about the living clonal organism? So if we try to know which is the oldest and heaviest known living clonal organisms, again we go into a tree. In this picture you can see pando or also called the trembling giant. This is in the United States, and it's considered to have 6 million kilograms of biomass, and there is an estimation of around 80,000 years old. So some analysis based on DNA, have concluded that Pando is one and only organism that has a very big root system underground. Now that I have explained to you the definition of the forest. And also we have seen some peculiar trees and forests, I would like to talk to you about the annual net gain and losses of forest in the world. So that area is, do we know if we have more forest now or less for is done than in the past? So depends on the country here in this map made by a report of 2015 by the fall. You can see how in the south hemisphere there are more net losers. And in the north hemisphere there are more net gains are forests through the time. So now we jump, we jump into the concept of forest dynamics. So basically the idea is that forests are not static systems, they change through the time. So when we talk about forest dynamics, we talked about the changes in the structure and composition of the forest over the time, including its responses to human and natural disturbances, as you can see in this is scheme. So we have seen how forests change over the time, and functioning of the forest have an important role on water fluxes, nutrient cycling, carbon stocks and primary production. By Amazon carbon stocks in forest are important indicators of the productivity and the capacity to sequester carbon. The role of forest as sinks and sources of dioxide carbon, the concern about this has been increasing since the protocol of Kyoto in 1997 of the United Nations Convention on Climate Change. And since we know how CO2 have an effect of climate change, and it is an important concern for humans. So forests they store around 45% of the terrestrial carbon, they contribute to around to approximately 50% of the primary production, and forests absorbed around a third of the atmosphere CO2. Well, now we can see how can we study forest. So how can we do it? We can do it many different ways depending basically on the scale, we want to study them. If we study them in landscape scale, we can use Gs, like the geographic information system methodologies, for example, or if we go in a lower scale, we can use plots. Here in the video, you can see how we are doing a plot. This is defining a concrete area to sample inside this area and have the information for that area. This is a strapline and you can see how Andreea and me are preparing this plot to sample it. We can also study forests at a more individual level at a tree level. So diameter at the breast height is one of the most used methodologies to study the three sizes and have information about that. Also, if we work at an individual level it is important to label the individuals and mark them in order to be able to follow the tree over the time. We have seen that first change over the time, and now we are going to talk about four is functioning, which has an important role on water fluxes, nutrient cycling, carbon stocks and primary production. Biomass and carbon stocks in forests are important indicators of productivity and the capacity to sequester carbon. The role of forest as terrestrial sinks and sources of carbon dioxide has received increasing attention since the adoption of the 1997 protocol of Kyoto in the convention of the United Nations for the Climate Change. And also since we know that CO2 has an important role on climate change, and that it is an important concern for humans. So forests store around 45% of the terrestrial carbon, they contribute to approximately 50% of primary production and forests absorb around a third of the atmosphere CO2. So now we are going to see, how can we study forests. We can study forests in many different ways. And basically the way that we are going to study the way depends on the scale we are working. So for example, if we work on a landscape and a big landscape scale, we can use techniques of Gs which are the geographic information systems for example. Or if we go into a lower scale, we can use plots to sample part of the forest and have our information inside the plots. Or maybe, if we want to work in a more individual level, at the tree level, we can use other techniques more related to study physiological variables for example. So here in the video, you see how Andreea me we are constructing a plot in a strapline in order to sample the biodiversity inside of this plot. So this is a strapline that we could do also in a forest on or any other ecosystem. And you can also see how I'm measuring the diameter at the breast height, which is one of the most used techniques to measure the three size. And so it is important if we, if we want to study at an individual level, at the three level it is important, the labeling. So it's important to label the individual so that we can follow the growth or whatever that we are studying over the time. [MUSIC]
