* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Mise en page 1
Latitudinal gradients in species diversity wikipedia , lookup
Island restoration wikipedia , lookup
Conservation agriculture wikipedia , lookup
Natural environment wikipedia , lookup
Renewable resource wikipedia , lookup
Habitat conservation wikipedia , lookup
Biodiversity wikipedia , lookup
Perovskia atriplicifolia wikipedia , lookup
Aftermath: Population Zero wikipedia , lookup
“When biodiversity brings my city to life!” 1 t s e e h What is biodiversity? Document produced by Veolia Environnement sheet 1 Biodiversity – everyone is talking about it. e be don o t y t i Activ with your mates class But what is it? Biodiversity is the whole range of life which surrounds us. Biodiversity… is life! Look around your classroom, your village or simply in the street – how many different people there are! There are no two people the same, even in your family. We all look like our father, our mother, our brother or our sister, even our grandparents. But only a little bit. We are each unique. We each have our own character, personality and talents… even identical twins. This diversity can also be seen between ethnic groups and peoples. Each one has its own customs, its view of the world, its language and sometimes its own morphology. The same is true in nature. In the school yard, in a park or in the forest, listen to the songs and calls of the animals. Identify their tracks (paws, claws, droppings, abandoned feathers, etc.). Finally, look at the shapes of the plants. So much diversity… But to be certain, you need to compare. Go to a park, a forest, an area of grassland, a meadow, a simple copse, a farm, the side of a road or a river. How many types of plants can you count in each of these places? Try to grade them: which environments appear to you to be poor and which rich? — Keywords Biotope: natural habitat of one or more species. Food chain: series of living organisms which eat each other. Ecosystem: a food web within a biotope. Species: collection of individuals capable, through reproduction, of producing fertile offspring (capable of reproducing). Ethnic group: group of humans who share a common language and culture. Habitat: place where individuals from one or more species live. Individual: representative of a species (plant, animal, fungus… anything!).. Morphology: shape, structure and appearance. Sexual reproduction: production of a new generation of individuals using the sex organs. Sexual reproduction enables the mixing of the male and female genes. Asexual reproduction: reproduction without sex, through budding, division, etc. There is no mixing of genes so the descendents are almost clones of their genitors (almost, since there are always some errors in the transmission of genes). Int o i t a t erpre n Biodiversity means both the number and… the diversity. It is landscapes, ecosystems, habitats, living environments and all that they contain – species – and above all the relationships they have among themselves and with their environment. Within each species are individuals, which are all different. Specific diversity Genetic diversity Ecological diversity The first thing you notice when you observe your surroundings, “looking for” biodiversity, is that it is everywhere. There is a biodiversity of individuals, e.g. your class or village. This biodiversity comes from reproduction, which mixes the genes of the mom and dad. Specialists call this “genetic diversity”. There are more similarities between two individuals from the same family than between two individuals from different ethnic groups. Then there is diversity of species. This is called "specific diversity". Bacteria, plants, animals, whales and earthworms, grass and baobabs… Specialists have identified 1.8 million species, but have not agreed on a total number. Probably between eight million and… 100 million! Why is this important? If more species can be counted in a forest than in a meadow, does it mean the meadow is not as “rich”? Certainly not. On another level, there is "ecological diversity”. This refers to various landscapes and habitats. A region may have few species, but many landscapes. This is true of France, which specialists refer to as "megadiverse" since it contains many very different landscapes in a small area. However, it has less species than Alto Mayo, a very small region of northern Peru… There is also less diversity in relationships, “interactions” between individuals in populations, between populations, between species in their habitats, and between species and their habitats. Everything is linked. The living world is a giant tapestry, in which each thread is a species, an individual or an ecosystem. When a thread becomes loose, there is the threat that one day the whole tapestry will disappear… Biodiversity does not like standardization. In a very small surface area, there can be a very high level of biodiversity if there are a lot of different habitats. L § s e ot N There’s more to life than species! Sexual reproduction – a good thing for biodiversity! A species which divides or buds produces descendants very quickly and in very high numbers. But all its descendants are identical! This is asexual reproduction. If a disease or parasite arrives, the whole of this little world risks being affected. With sexual reproduction, however, individuals from a single species are all different. This means each will react differently to the disease or parasite. Ultimately, sexual reproduction enhances genetic diversity. “There were so many species in the past and there are fewer today.” That is easy to understand. But it is meaningless, since biodiversity is about more than simply species. It is much more complicated than that! Species alone do not make biodiversity… What is important is the network that species form with one another. Asexual reproduction Sexual reproduction Biodiversity is like a tapestry in which each thread is a species. The more threads there are, and the tighter they are, the better an attacked ecosystem will be able to return to health. “When biodiversity brings my city to life!” 2 t s e e h Can cities be part of “nature”? Document produced by Veolia Environnement sheet 2 In search of urban biodiversity — Keywords e be don o t y t i Activ with your mates class Are cities enemies of nature because they are artificial? You only find what you look for. Look for nature around your town or city! Look for the wild grasses, enormous trees, birds, mammal tracks and frogs’ calls! Explore your neighborhood, village or town in a small group for a set amount of time (e.g. two hours). Cross it from one side to the other, in a straight line, in any direction. This is called a "transect". Mark any "places of nature" you find on a map. A copse, a garden, a pond or just a crack in the wall – for each one, note down the different forms of life (flowers, trees, moss, butterflies, etc.) and, for each one, estimate how abundant they are (using symbols, e.g. stars, from “not many” to “a lot”). Then visit the suburbs or the countryside outside the town. Conduct the same experiment – take a walk! Note down what you see and estimate the abundance. Mark these "places of nature" on a map and describe in detail the environments you come across (field, meadow, vineyard, cattle farm, etc.). Back in the classroom, draw up a nature profile of your neighborhood, village or town and decide which environment (city/town, suburb, village or countryside) is the "richest”? Intensive farming: type of production involving immense plots of land and the massive use of pesticides, fertilizer and agricultural machinery. Wildlife corridor: space linking natural environments to one another. A path, road, tunnel or series of parks and gardens could all be corridors. Fauna: all the animals living in a single place. Flora: all the plants in a region. Fragmentation: separation of a biotope, habitat or ecosystem, into several fragments as a result of urbanization and agriculture. Wasteland: space without a use, abandoned, taken over by flora and fauna. Pesticide: chemical product used to combat any sort of parasite (animal, plant, fungus, etc.). Chicago, United States Int o i t a t erpre n It is surprising to discover how much “wild” life there is in cities. By taking a closer look at towns and cities we can rediscover parks and gardens, appreciate the height of buildings and street lamps, notice damage to walls and roofs and cracks in the sidewalk... Ljubljana, Slovenia Yes, towns and cities are rich in fauna and flora. You can find birds, reptiles, amphibians and mammals. How does this miracle come about? Because the city provides a whole range of habitats for plant and animal life. Cities contain holes, cracks, walls, courtyards, embankments, gardens, flower pots, parks and ponds… In other words a range of soils, different levels of exposure to the sun and varying levels of humidity. This is of great benefit to “wild” life. L Bombay, India And water is also always available in towns and cities, even though it may be lacking in the surrounding countryside. And towns and cities contain streets, sewers, canals, railroads – all paths of communication for fauna. These wildlife corridors allow animals to travel between their various habitats which may be divided up by urbanization. Other corridors exist in the air: tall buildings, lampposts and trees in parks are also sanctuaries for birds! It is no surprise that some towns and cities can be richer than the countryside: sometimes they are surrounded by countryside that is arid, polluted or fragmented by roads and parking lots. This is an example of the “refuge effect”: threatened or disturbed everywhere else, flora and fauna can find relative peace in towns and cities. For us, cities are artificial. For plant and animal life, cities provide a wide range of habitats. Towns and cities are full of food – our waste! This attracts many animals and some end up not being able to live without humans. § s e t No The city is a good mother In the city there is always shade even when it is very hot. When it is cold, there is always a source of heat (heating, subway, traffic, etc.). The city is a haven for plant and animal life. The protective city The city provides a whole range of habitats for plant and animal life: gardens, embankments, flower pots, etc. It provides animals with communication channels: sewers, railroads, canals, etc. This helps them get around! Plant life can grow in the smallest patch of bare soil. A crack, a hole, the edge of the road or a huge abandoned plot, these “wastelands” are an opportunity for biodiversity. They should be left to live, without pesticides, and only occasionally cleared. “When biodiversity brings my city to life!” 3 t s e e h Nature in cities, but where? Document produced by Veolia Environnement sheet 3 But why is there so much life in cities? In one place there are flowers, butterflies and mammal tracks, but not in another. done to be y t Why? i v r i u Act ith yo w mates class [Same activity as sheet 2, but in a different way] Explore a neighborhood for a set amount of time… Each group sets out to look for "stations" — places where flora and fauna are to be found. Firstly these need to be marked on a map, then described as accurately as possible: what is the surface area (small, medium, large, very large), what is the soil like (earth, stone, pebbles, rubble, a wall, etc.), is the station in shade or well lit (by the sun or a street lamp?), is there water, humidity, or is the station “dry”, what sound is there… "type" (edge of the road or river, a garden, a square…), is it looked after or abandoned? Don’t forget to note down an important piece of information on your sheets: is the station affected by human life? (Is there noise, pollution, waste? Do a lot of people pass it, trample over it, etc.?) Once each station has been fully described, try to assess the variety of species. Do you think it is low, medium or high? All the groups compare notes to identify anything which the richest and poorest stations have in common. What seems to encourage or discourage biodiversity in towns and cities? Finally, the groups meet up and share their observations. All the stations, with their level of richness and surface area, are plotted on a map. Is the richness or poverty of the stations localized? Is the richness linked to stations’ surface area? — Keywords Archipelago: chain of islands. Noise: this disturbs many animals, which therefore avoid it. Trampling: repeated crushing of plants which leads to a decline in plant biodiversity, in favor of a few very ground-hugging and hardy species. Residential neighborhood: quiet neighborhood made up of houses or low apartment buildings. Surface area/species ratio: the larger the surface area of a natural environment, the higher the number of species found there. This rule applies particularly to isolated environments, such as islands and city parks. Street lamps: artificial light disturbs many species, e.g. birds, because it prevents them from properly sensing the change from day to night. Int o i t a t erpre n Cities are a sanctuary for flora and fauna – a real archipelago. Gardens, squares and parks are islands which form an enormous and varied surface area if they are connected by corridors. Paris, France The places in the town or city where biodiversity is strongest are naturally parks and gardens. Why? Because they contain different sorts of environments: copses, hedges, shrubs, trees of various heights, areas of water, ponds and rivers. Because they are generally large. And yet the larger the space, the more chance flora and fauna will have of finding habitats which suit them. In principle, the diversity of species in city parks and public gardens is therefore high. L Chicago, United States In practice these parks and gardens sometimes do not have a high level of ecological diversity, since the habitats they offer are all similar. This happens if gardeners have only planted a single type of tree and grass, for example. This very small number of habitats will encourage a very small number of species. Scientists think that parks, squares and gardens are like islands. An island’s flora and fauna is isolated from other islands by the streets and buildings. But there is a solution! Rows of trees, river banks, tunnels and hedges help flora and fauna travel from one green space to another. They become wildlife corridors and can be compared to bridges linking islands to one another. Thanks to these wildlife corridors, the total surface area of green spaces in towns and cities can be considerable. That explains why residential neighborhoods are often “greener” than city centers: they contain a lot more varied gardens, hedges and trees close to one another. Fauna does not like being disturbed and flora does not like being trampled. Biodiversity moves into quieter areas of towns and cities to escape the noisy, overcrowded areas. § s e t No The biotope of skyscrapers Pollution? Not for everyone! At first glance, polluted areas do not appear particularly favorable to biodiversity. However, if humans do not clean them up, they are colonized by strange plants which do not mind pollution. These plants gradually absorb the pollutants in the soil as they grow. United Kingdom In city centers, skyscrapers and religious buildings are often a haven for birds which, in the wild, like cliffs and tall trees. They are also home to birds of prey which feed on the fauna in parks and gardens… There are a lot of birds in towns and cities, thanks to tree-lined avenues. Unfortunately if the same species of tree is always planted, the habitats available to birds will always be identical. Habitats, and therefore plantings, need to be diversified for there to be many different animal species in a town or city. “When biodiversity brings my city to life!” 4 t s e e h They are invasive! Document produced by Veolia Environnement sheet 4 Colonized cities? Cities can favor biodiversity. Some species have taken advantage of e be don o t y t this to the extent that they have A c t i v iw i t h y o utre s ma class invaded it and can cause damage. Cities are a refuge and have a high level of biodiversity. However… have you noticed how some species are a lot more common than others? Let’s take the example of birds. In a city park, look for a long time at the top of the highest buildings or a large area of water. Take the time to let your eyes adjust. Then note down on a sheet of paper the “types” of birds you see the most often. It doesn’t matter if you do not know the name of a species! Just note the “type” — a shape, a way of flying, or the particular formation of a flock of birds. The aim of the exercise is to identify the types which are there all the time, i.e. those which are more numerous than others. You can do the same with butterflies, by assigning yourself a “post” in a meadow or flowered garden. The same exercise can be carried out for plants. In a park or a public garden, then in an area where vegetation grows “spontaneously” (without having been planted, e.g. in the street or on wasteland). Finally, in a neighborhood with a lot of private gardens, ask yourself this question: are there “types” which are also there all the time? — Keywords Anthropized: influenced, controlled, modified or managed by humans. Commensalism: a relationship between organisms in which one benefits from the other without harming it too much – humans and species in cities, for example. Invasive: a species, breed or variety which directly or indirectly harms humans. Resting place: tree or pond on which flocks of birds sit to exchange information. Int o i t a t erpre n The living conditions offered by cities are often so favorable that some species find it hard to live without them. Some have grown in number so much that they have become a serious nuisance. Biodiversity is especially strong in towns and cities because “green” spaces (woods, gardens, planted land, wasteland, etc.) are large and linked to each other. However, one thing is noticeable in even a very green town or city: the same species are always seen. There are few of these species, but their numbers are very high. Let’s take the example of a city and a natural ecosystem. In cities, you often notice that some species have very high numbers L compared to others. In the natural ecosystem, species’ numbers are often similar to each other. This permanent unbalance is how you can recognize an artificial or anthropized ecosystem, i.e. one influenced by humans. As a result of this “refuge effect” in towns and cities, some species reproduce better and faster than in the wild. Their way of life has been modified so that they can make the most of the “benefits” offered by humans. And some species have become… urban. Why is this? Because it is difficult for these species to live without humans. They are commensal… on humans. They are the ones you see the most because their numbers are huge: pigeons in European and American towns and cities, or rats, cockroaches and termites all around the world. Humans sometimes find these species a nuisance! What can be done to avoid invasion by certain animals? Firstly, we must avoid feeding them. Urban fauna takes advantage of the abundance of food. Make sure trash cans are properly closed! § s e t No Too many Imported plants Gardeners often plant the same varieties of plants because they grow quickly, require little maintenance and are cheap. These plants then re-seed themselves and become… invasive. birds? Clip your hedges… Some birds live in enormous flocks. They need resting places, trees or shrubs to meet up and exchange information. So if there are really too many, prune some of those trees and shrubs! The droppings of town and city animals are a source of dirt and degradation. They can contain infectious parasites and need to be cleaned up. “When biodiversity brings my city to life!” 5 t s e e h Let’s encourage biodiversity in cities! Document produced by Veolia Environnement sheet 5 — Why are some neighborhoods "greener" than others? Explore the architecture and urban planning of green neighborhoods… Keywords Architecture: the art of designing plans of buildings and then constructing them. be don y to ur t i v i t Ac with yo mates class Based on the other sheets and the work already done, make suggestions to explain why some places are “greener” than others. Here are a few little gardening jobs to help you. Find a part of the school where there is nothing: no plants and no insects. How can you change that? Make suggestions! You will need flowers, so sow some in pots, bags or anything else suitable. You can also add plants and shrubs you find in the wild (don’t take too many), in your gardens or bought from a store. Arrange them however you want – on the ground, on chairs, etc. Also place containers of water between the pots. If the “poor” part of the school happens to be earth, dig it over. Then sow an assortment of seeds, and plant other plants and shrubs in the ground. Create small ponds and place pebbles and stones in them. Have fun! Try whatever you want! The main thing is that the plants grow and that the insects and birds come. If you think there are not enough insects and birds, start the experiment again. Make suggestions to improve the biodiversity in your school… then in your town or city! e Residential block: group of houses organized around a courtyard, garden or a park. Organic matter: matter containing carbon which is produced by living things: plants, animals and micro-organisms. Soil microfauna: fauna in the soil invisible to the naked eye. Monotypic: habitats comprising a single species. Green wall or roof: wall or roof covered in a surface on which plants can grow. It is a construction technique also used to insulate buildings from the outside. Urban planning: the art of designing and constructing towns and cities. Urban planners are a bit like architects, but instead of designing buildings, they design towns or areas of a town or city. Int o i t a t erpre n Even modern, dense, noisy, polluted cities can prove very favorable to biodiversity. By agreeing to “lose” a little space, green islands can be created, connected by corridors. Life is even possible in city centers! Puteaux, France It is obvious when you walk through the streets that biodiversity can be found anywhere there is vegetation! So the only thing you need to do to increase biodiversity in towns and cities is make them greener: plant or give nature a chance to “selfplant”. But how can this be done in very “tightly packed” cities, where land is scarce and therefore very valuable? How can this be done in cities surrounded by a great expanse of suburbs which divide the natural environment up into lots of fragments? L In cities, in a very concentrated habitat, we can agree to lose a little “useful” space to help nature: planting the courtyards of apartment buildings, climbing plants up walls, laying out flower borders, creating “green” balconies and even roofs. But be careful of always planting the same thing, either to make it easier, because it is fashionable or to keep costs down. Biodiversity not only means green, but several shades of green! Nature also benefits hugely from wasteland. Often an area of grass which has never been mowed is enough to attract insects, birds and small mammals! City gardeners can put the same idea into practice in parks and gardens. They can leave a small area fallow, digging or mowing as late as possible. They can leave dead leaves to rot on the lawn or the earth. These provide a home to microfauna and enhance the soil with organic matter. “Green” urban planning favors small islands of biodiversity (parks, gardens, vegetable plots) and corridors connecting them (tree-lined avenues, river banks, etc.). Towns and cities must agree to leave some space for vegetation. This space need not necessarily be used to create city parks – planting a little everywhere can achieve a lot! § s e ot N Vertical nature Architecture can also favor biodiversity. Climbing plants, balconies with trees, “green roofs” and even “green walls”? Housing estates in blocks There is something even better than back-to-back houses: the ideal is small apartment blocks of different sizes with patios and balconies – real little “islands” around parks. Chicago, United States Puteaux, France By encouraging biodiversity in town and cities, we attract birds. But these can hurt themselves on windows, which they can’t see. To help them avoid these, silhouettes of birds of prey can be stuck to the glass! “When biodiversity brings my city to life!” 6 t s e e h Biodiversity? Vegetable plots! Document produced by Veolia Environnement sheet 6 Is my vegetable plot part of biodiversity? Growing vegetables and fruit is not very difficult. You just need to know a few “tricks” which city-dwellers have often forgotten. be don y to ur t i v i t Ac with yo mates class e Together, collect some vegetable seeds and plants. As many as possible – you'll need a lot! Split yourself into two groups. One group will sow seeds and put the plants into several pots – as large as possible. The other group will sow and plant in the ground. Where? If possible in the soil in the school yard, which will need to be dug over. You can also create a plot in an authorized area, bordered by four planks which you fill with earth (up to 30cm high). The first group, with the pots, will grow half of them in the classroom and the other half outdoors (try to have several examples of the same plants in each half if possible). The group will arrange them in all possible combinations: side by side, at various intervals, horizontally, vertically, at an angle, etc. The first group will also try all possible living conditions: in the shade, in the light, in a dry and a humid atmosphere, in the heat and in the cold, etc. How do plants grow? What are the ideal conditions? The second group will discover the joys of the vegetable plot. Can it manage on its own? Why not ask advice from adults who have their own vegetable plots. Students from both groups will come together regularly to discuss their difficulties and their observations. Together they will discover flowering and pollination. They will organize a gathering for all the students’ parents to celebrate the first harvest… — Keywords City-dweller: someone who lives in a city. Organic waste: dead plant or animal matter. Parasite: organism which lives off particular crops in the vegetable plot. Proper maintenance and watering make it possible to control some of them. Seedling: a plant at the start of its growth, which will later be transplanted (replanted). Herbs: plant with a strong flavor used in cooking. Herbs store up pollutants from the air. Vegetable plot: special sort of garden for growing fruit and vegetables. Int o i t a t erpre n There are many advantages to vegetable plots in towns and cities. They are economical, attractive, social and environmental. They need watering of course… Vegetable plots have the advantage of increasing the town or city’s green space. There is also another advantage – they provide us with something to eat! Yes, eat, because a vegetable plot means food as well as plants! Fresh food which those who eat it, who want to know where their food comes from, can have confidence in. But where can you plant vegetables, shrubs and fruit trees? Almost anywhere. In any container high enough and with a hole at the bottom (so the water can escape). You can grow a plant in almost any position L (including in a vertical support, such as a trellis). The main thing is that the plants have light and, most importantly, water – that is vital. When the weather is hot, plants need to be given a lot of water. One way of watering them is to collect rainwater… Owners of gardens can mark out a vegetable plot. All you need is enough space. Towns and cities can also allow green spaces or wasteland to be transformed into communal vegetable plots. As well as the food they provide, communal gardens encourage contact between inhabitants. Growing fruit and vegetables in towns and cities is also a way of preserving agricultural knowledge which is being lost. And by encouraging city-dwelling gardeners to grow rare varieties, society makes them curators of agricultural biodiversity! Finally, vegetable plots are relaxing for city-dwellers. Working the soil, seeing what you have sown grow and harvesting after months of waiting all help reduce stress. You can grow fruit and vegetables at home. If there is not much room, they can also be grown in a window box on a balcony! § s e ot N Vegetable plots mean recycling! A vegetable plot is also a way of recycling organic waste if you fertilize it with compost. It is also an effective way of filtering the air of its pollution. But make sure you wash the fruit and vegetables before eating them! Tomatoes Companion planting for a less chemical vegetable plot If correctly combined, some varieties of vegetables and flowers protect each other from their respective parasites. It is therefore not always necessary to use chemicals to protect your vegetable plot. Here are some examples: Basil Radishes French marigolds Lettuces Chives Carrots Beans Rosemary Sweetcorn Beans Sunflowers Cabbages Thyme Celery Potatoes Keeping bees in the city? Why not! Bees sometimes find more flowers to gather pollen from in towns and cities than in the surrounding countryside. The honey they produce has more flavor and sometimes also contains less pollutants. And establishing beehives in towns and cities also means protecting bees, which are on the decline all around the world. “When biodiversity brings my city to life!” 7 t s e e h Biodiversity and our waste? Document produced by Veolia Environnement sheet 7 Garbage-collecting animals and recycling worms We can cut down on waste by turning one o be d t y t i Activ with your it into fertilizer. Give it a try! tes assma cl Compost can be used to make natural fertilizer. How? It’s very simple. You need quite a large plastic container 1 20cm to 30cm high. Pierce about 10 holes 5mm to 8mm wide at the bottom. Then, about 5cm high, spread out a mixture made up of organic waste (not grass), very fine soil, paper and shredded card. Sprinkle water over the top… then drop some earthworms into the mixture. What type? Ones that live in the soil where you live. You can find them by digging the ground. How many? A 2 maximum of 500g for 10cm (be careful, the bin will be heavy when you’ve filled it up!). After you’ve added the worms to the mixture, cover with a thin layer of kitchen waste (no acidic products like citrus fruit, onions or leeks). It’s almost finished. All you need to do now is place two other identical containers 2 3 on top of this one. Fill them every day with organic waste, paper and card… As soon as the worms have digested the contents of the first container, they will move onto the second, and so on. Don't forget to put a cover over the highest container as worms don’t like the light. Also remember to place another container under the first, pierced with a single large hole 4 . After a few weeks a juice, the “tea”, will run out of this hole. And all that will be left in the first container is a very fine soil, the compost. Tea and compost – you have just made two very effective natural fertilizers! 3 2 1 4 — Keywords Compost: mixture of earth and the product of the natural decomposition of organic matter. Waste: what is thrown into the trash can. Organic waste: dead plant or animal matter. Fertilizer: product added to soil to help plants become big. Compost is a natural fertilizer. Organic matter: matter containing carbon which is produced by living things: plants, animals and micro-organisms. Methanization: transformation of organic waste into compost and methane. This process occurs in a “reactor” sealed off from oxygen and light. Phytoremediation: removal of pollution from the soil by plants. Tea: the “juice” which runs out of a composter after a few weeks. Int o i t a t erpre n Nature has the ability to recycle. Biodiversity transforms part of the waste it produces. 1 Composting is a system which reveals biodiversity’s role as a recycler. This is what happens in nature, as well as in parks and gardens: fauna and micro-organisms in the soil (worms, insects, mites, bacteria, ants, fungus, etc.) eat abandoned organic matter (dead leaves, pine needles, etc.) 1 . They transform them into a sort of very fine soil (compost) 2 and a dark liquid (the “tea” in the experiment). This solid and this liquid contain nutritious matter which feeds plants. In this way, biodiversity maintains 2 itself by recycling its dead organic matter into fertilizer. This natural fertilizer will ensure that the soil is good quality. New plants and trees will be able to grow 3 . Composting also has a symbolic value, since it shows that waste nourishes fauna in towns and cities. One major reason there are so many animals in towns and cities is because there is so much waste: abundant food all year round, without the need to hunt it. This is a blessing to animals! 3 It is a hazard to humans, however. Animal droppings are a source of dirt, which is harmful to health and hygiene. Flora can also be of service to humans. When the soil is polluted, specific vegetation always develops. By clearing it regularly, the pollution is cleaned from the soil since these plants concentrate it in their tissue… Plants can therefore help clean up a polluted area. After a few years, the site can even become a garden or a park! This is called phytoremediation. Towns and cities nourish their st biodiversity. But 21 -century humans produce a lot of waste. It is very important for us to give nature a helping hand, through the sorting, disposal and treatment, as well as recycling, of waste. L § s e t o N Waste can also be used to produce energy! They take advantage of our waste Waste that builds up in the street attracts animals. That causes damage which is harmful to health and hygiene. And it’s also not very pretty! Waste should be placed in garbage containers. Make sure the lids are properly closed! Grass clippings and kitchen waste placed in sealed tanks is transformed into compost by bacteria, as well as into methane. This gas can be used directly for cooking or to turn turbines to generate electricity. Humans produce a lot of waste. Biodiversity is naturally capable of recycling a small proportion of it… Humans must obviously lend a hand – by sorting and recycling their waste they can give it a second life! This also benefits nature since recycling waste means using fewer natural resources. “When biodiversity brings my city to life!” 8 t s e e h Biodiversity, going with the flow! Document produced by Veolia Environnement sheet 8 How can biodiversity reduce flooding? one o be d t y t i Activ with your mates class Nature controls our water supply. How? In particular using plants. Experiment 1 / Take a rectangular container 20cm high. Fill it to the top with earth, without tamping it down. Then support it, so that it is tilting, above a sink. All set? Now slowly pour the contents of a watering can over the container. Repeat the process until the water overflows. How long (or how many watering cans!) did it take? Repeat the experiment, but this time tamp down the earth. Now let the container dry and, when the earth is really hard, repeat the experiment again. Which earth (not tamped down, tamped down and wet, or tamped down and dry) did the water overflow from the quickest? Experiment 2 / Now fill up a container of earth and plant a lawn in it. Pour over the contents of the watering can when the lawn is short. Time how long it takes for the water to overflow. Then leave the grass to grow until it is high, and pour over the contents of the watering can again. In another container, plant wild grass or put in a square of wild grass or flowers you have dug up. Again, time how long it takes for the water to overflow… Can you now grade the containers of earth used? — Keywords Agglomeration: collection of towns linked to each other. Upstream: above, part of a river located before a city, for example. Downstream: below, part of a river located after a city, for example. Compacted: soil which is so tamped down it is impermeable. Impermeable: waterproof, does not let water or gas pass through. Lawn: fine grass cut regularly so that it remains short. A lawn contains very few species. Humidity: presence of water or water vapor in the air. Soil microfauna: fauna in the soil invisible to the naked eye. Grassland: natural surface covered in a large number of plant species, which can be mown twice a year (particularly to feed cattle). Soil: fertile part of earth. Int o i t a t erpre n Living soil is essential to reduce flooding and naturally clean water. In the experiment, water flowed faster over the surface of the bare soil soil than the planted soil. It is even faster over the surface of tamped down, dry soil! Why? Because when rainwater falls, the soil “drinks” it. In fact, the water fills the spaces between the grains which make up the earth. When all these spaces are filled (e.g. when the earth is tamped down), the earth can no longer absorb anything and water which then falls on it is forced to flow over its surface – it is said to “run off”. This can cause flooding. There are no empty spaces in bare earth compacted (tamped down) by farming machinery, dryness or frost, and water streams almost as quickly as over the surface of a road. Exactly the opposite effect occurs on grassland – which retains the water for a long time because it has a lot of roots and a high level of microfauna – due to the fact that there are a lot of spaces in the earth. Vegetation is therefore very beneficial to us. It provides natural protection against flooding. What happens in towns and cities? An agglomeration is largely impermeable as it contains a lot of road surfaces. This stops water infiltrating it. When it rains heavily in a short space of time, the drains overflow, rivers downstream fill up and this leads to flooding. Unfortunately large areas planted with lawn or cereal crops do not absorb a lot of rainwater, especially if they are not surrounded by hedges or trees to hold some of the run-off water. Noortalje, Sweden L Wetlands (marsh, ponds, wet grassland, etc.) disperse floodwater as well as providing water storage, even in summer. It is really very important to make towns and cities greener upstream! § s e ot N More worms, less flooding! Meadows hold water and remove pollution, since there are so many roots and so much fauna, including earthworms. By drilling through the soil, roots and earthworms aerate it and increase its ability to absorb water. Nature plays a crucial role upstream of cities Wetlands help to clean the quality of the water. In a pond, water can be filtered by aquatic plants and microorganisms. Wetlands also often have a very high level of biodiversity! Wetlands help to clean the quality of the water. In a pond, water can be filtered by aquatic plants and micro-organisms. “When biodiversity brings my city to life!” 9 t s e e h Biodiversity cools cities Document produced by Veolia Environnement sheet 9 It feels better in the shade and the breeze! It is good to plant trees and hedges and to create parks and gardens, which increase e be don o t y t i Activ with your biodiversity in cities! mates class It makes it easier to breathe. In this experiment you will record the temperature you feel (are you slightly hot, hot or very hot?), and the temperature shown on the thermometer (make sure you place it at head height, if possible to the north if you live in the northern hemisphere, if possible to the south if you live in the southern hemisphere! The most important thing is that the sun does not shine directly onto the thermometer). Stand right in the sun. What do you feel? Firstly with a bare head? Then with a hat on? Then under a parasol or an umbrella? Then with an electric or hand fan? In which situation do you feel most comfortable? When you feel most comfortable, has the temperature really fallen? Now stand under a tree in the town or city. Again, record the temperature you feel and the temperature on the thermometer. Do the same next to a variety of water sources – a river, a fountain, a pond, a water fall or a jet of water. When you get back to school, stand in front of a fan. Set it to medium power and throw flour in front of it. This time repeat the experiment, placing a few plants fairly high up between you and the fan… Finally, take a plant and place it in the shade. Entirely cover it in something transparent. What do you observe? (When it wilts, uncover it and water it!). — Keywords Heat island: accumulation of hot air above cities. Evapotranspiration: accumulation of evaporation from the land and plant transpiration. This water evaporates into the atmosphere due to the effect of heat. Particle filter: device placed on a chimney or beneath a chimney pot. It traps some fine particles and reduces pollution. Real temperature: temperature displayed by a thermometer. This is measured in the shade. Comfort level: perceived hot or cold. Int o i t a t erpre n Vegetation is an excellent insulator. It is also a very effective particle filter and air dehumidifier. It is important to incorporate it all around the city. The big problem with modern cities is the heat. They concentrate heat, firstly because they are covered in asphalt. During the day this road surface absorbs heat, some of which it releases into the air at night. This means summer nights are never cool in big cities! Secondly, in big cities there are a lot of vehicles which give off a lot of heat. Unfortunately very little of the energy contained in gasoline is transformed into movement – most of the energy is lost in the form of heat! This heat has trouble escaping. Wide avenues and straight streets bordered by skyscrapers capture it. The same phenomenon can be seen in the courtyards of apartment blocks. All this accumulated heat creates a sort of bubble above cities, from which air and pollutants cannot escape quickly. However, it feels better in older cities even when it is very hot. Why? Because their streets are in shade, because the houses’ thick walls keep the heat out and because there is… water and vegetation. In general, trees, shrubs and vegetation benefit us enormously. Firstly, trees create shade and increase the movement of the air. Climbing plants insulate walls from the sun’s rays during the summer and retain some heat during the winter. This means that green walls provide good insulation for homes. Vegetation also has a third advantage: trees and shrubs are able to retain certain pollutants and particles suspended in the air. They are therefore very effective filters against pollution. Finally, don’t forget that vegetation also loses water when it transpires, in a process called transpiration. When it is hot, plants and the soil release water into the atmosphere, in the form of water vapor. This phenomenon explains the coolness and humidity you feel when you walk in a forest. The same cool sensation can be felt by a pond, a river or close to a waterfall or a fountain. Shade, wind, water and plants allow cities to suffer less when the weather is very hot. L § s e t No Natural insulation Vegetation is useful even when the weather is not hot. By acting as a screen against the wind and the air, trees, shrubs and climbing plants help to insulate walls. Vegetation and water – two heat pumps Plants lose water through transpiration. Aquatic areas and soils lose it through evaporation. The combined effect, known as evapotranspiration, is a physical process which consumes energy. By transpiring, a plant takes heat from the atmosphere. So it cools it – a little! In exchange, it gives it its water, the humidity which will later be transformed into… rain! Urban forests have a well-known role in combating pollution – they filter particles and some pollutants released by exhaust pipes. “When biodiversity brings my city to life!” e h s 0 1 et Zoos and museums, guardians of biodiversity Document produced by Veolia Environnement sheet 10 Why visit the zoo? Zoos are an ideal place to take a walk in cities. They are also somewhere to learn about the animal kingdom. Museums, meanwhile, done to be y t i v r offer an insight into the state Acti with you mates class of biodiversity. What is the purpose of zoos, zoological parks and menageries? Visit one. What species can you see there? Are they local (do they come from near you)? Make a list and, next to each species, note down where it comes from (which continent is enough). Then go and ask the managers or carers where the animals on display have come from. Also ask them about any births at the zoo. If there have been any, what do the newborns do? Then look at how the animals are cared for. Look at the coats and the feathers. Do you think the cages and enclosures are big enough, well maintained and decorated? Do the animals appear to be lively or tired? Then visit a natural history museum or, in a general museum, its section dedicated to animals. Are there many local species? As far as possible, for each local species, try to identify its “status” now (the species is not endangered, it is endangered, or is vulnerable or threatened, or even… extinct). Has species’ survival changed over time? Identify all the museum’s extinct species and try to rank them by the century in which they became extinct. — Keywords City-dweller: someone who lives in a city. Menagerie: a very small zoo. Museum: museum dedicated to the natural sciences and the study of life. Mounted: stuffed. Zoological park: a very big zoo. Reintroduction of a species: release of animals born in captivity (e.g. in zoos) into their natural habitat. Zoo: place where you can go to see animals. Int o i t a t erpre n Zoos, menageries and zoological parks now play a very important role in the conservation and safeguarding of rare species. And museums’ collections enable researchers to identify changes in biodiversity. Zoos, zoological parks and menageries are vital attractions for city-dwellers. Why? Firstly, to provide family days out. Going to the zoo is one of the leading leisure activities for families all around the world. It provides a chance to “rediscover nature”: seeing it and experiencing it is vital to our well-being. Even in a cage, biodiversity offers a little fantasy and relaxation. We all go to the zoo, because that is where we can see animal life under the best conditions (it is easier to look at a tiger and a vulture in an enclosure than a mammal or a bird that live in a city park!). Finally, for many of us, biodiversity above all means the biodiversity of our imagina- tion. An elephant, for example, attracts more attention than a red kite. In the last 20 years, zoos, menageries and zoological parks have played an essential role in the preservation of endangered species. Representatives of each species live in large, decorated areas, designed to be reminiscent in some way of their original natural habitats. Animals now breed in zoos, since that is where they live. Zoo animals are therefore no longer captured in the wild: they are born in zoos. When there are too many animals in a zoo, individuals are exchanged for other animals with another zoo. When they have reached their adult age, newborns of rare or endangered species are sometimes reintroduced into their original habitat. And museums and galleries of mounted animals give us an understanding of the fragility of species. It is upsetting to see species which no longer exist. And it is disturbing to see species which are still alive, but perhaps not for much longer. Museums are often also centers for research into biodiversity. Mounted examples make it possible to name and classify new species without the risk of error. This gives us an idea of the evolution of species’ biodiversity over time. Zoos are a magnifying glass for looking at biodiversity and help us to understand it. Museums preserve a memory of the past – they make it possible to assess biodiversity. L § s e t No The bond between Museums are also research centers Natural history museums are dedicated to knowledge, conservation of biodiversity and the relationship between humans and nature. They are also research centers. humans and nature In zoos, biodiversity is often more about heritage than the local area. The species that live there are part of our collective imagination. They keep alive in us the bond that still links our species with nature. Museums enable us to learn about species as they were described by scientists the moment they were discovered. By comparing these descriptions with current data, we can gain an idea of their evolution and their demography. September 2010 / Document produced by Veolia Environnement’s Communications Department. Editorial coordination: Julie Chavaribeyre / Copywriting: Frédéric Denhez / Illustrations (design and production): SLR / Illustrations: Laure Duquesne, Gilles Hureau / Graphic design: Valérie Charlanne, Téo Löhrer - Damien Lagier | COMAMA. Translation and layout: TagLine.