1 00:00:05,299 --> 00:00:17,739 An ecosystem consists of the physical environment and all the living things that live in that 2 00:00:17,739 --> 00:00:20,780 physical environment. 3 00:00:20,780 --> 00:00:26,440 The physical environment is the non-living component in an ecosystem. 4 00:00:26,440 --> 00:00:32,740 It includes non-living things like rocks, water and air, and also factors like temperature, 5 00:00:32,740 --> 00:00:40,340 humidity and light. There are two types of physical environments, terrestrial and aquatic. 6 00:00:40,340 --> 00:00:45,340 Aquatic environments can be fresh water, like rivers and lakes, or saltwater environments 7 00:00:45,340 --> 00:00:53,810 like seas and oceans. The living things in an ecosystem are the bacteria, animals, plants, 8 00:00:53,810 --> 00:01:00,649 fungi and protists living in it. You might have heard about the fauna and flora in an 9 00:01:00,649 --> 00:01:06,730 ecosystem? Well fauna refers to the animals and flora refers to the plants. 10 00:01:06,730 --> 00:01:16,189 All living things are grouped into species. A species is a group of similar 11 00:01:16,189 --> 00:01:23,430 living things that can successfully reproduce for generations. That means 12 00:01:23,430 --> 00:01:27,689 that if two organisms of the same species reproduce, like these two dogs, 13 00:01:27,689 --> 00:01:32,870 they will have baby organisms like this little dog that will be able to 14 00:01:32,870 --> 00:01:39,590 reproduce in the future. If two organisms of different species reproduce like 15 00:01:39,590 --> 00:01:45,650 this tiger and this lion they will have a baby organism and that organism won't 16 00:01:45,650 --> 00:01:51,230 be able to reproduce in the future. All living things in an ecosystem are 17 00:01:51,230 --> 00:01:57,769 organized so organisms of the same species form a population, different 18 00:01:57,769 --> 00:02:05,609 populations from a community and the community and the physical environment from the ecosystem 19 00:02:06,810 --> 00:02:17,370 finally all living things on earth make up the biosphere but let's talk now about ecosystems 20 00:02:17,370 --> 00:02:26,780 there are two types of ecosystems terrestrial and aquatic terrestrial ecosystems include forest 21 00:02:26,780 --> 00:02:34,330 mountain grasslands and desert and steppes. Forests are ecosystems with many trees. 22 00:02:35,370 --> 00:02:47,270 Those trees provide shelter and food for different animals. Two examples of forests are the Atlantic 23 00:02:47,270 --> 00:02:56,740 Forest with a humid climate and the Mediterranean Forest with a dry climate. In mountain grasslands 24 00:02:56,740 --> 00:03:05,289 plants are herbaceous, that means that they have soft and flexible stems. Grasslands usually have 25 00:03:05,289 --> 00:03:11,409 fertile soil. Deserts and steppes are found in very dry regions with extreme 26 00:03:11,409 --> 00:03:17,090 temperatures, so living things here need to be adapted to difficult conditions. 27 00:03:17,090 --> 00:03:24,479 Aquatic ecosystems include marine ecosystems and freshwater ecosystems. 28 00:03:24,479 --> 00:03:28,860 Water in marine ecosystems is in constant movement because of the 29 00:03:28,860 --> 00:03:34,719 carbines, waves and tides. In marine ecosystems we find sandy beaches which are 30 00:03:34,719 --> 00:03:41,080 affected by tides and waves. Crocusaurs are shallow areas with sunlight that 31 00:03:41,080 --> 00:03:47,860 allows algaei to grow. Open sea is the deep sea far from the coast. Sunlight reaches 32 00:03:47,860 --> 00:03:56,069 depth of about 100 meters so algaei cannot grow below this point. In fresh 33 00:03:56,069 --> 00:04:01,430 water ecosystems we found rivers. In rivers the water is always moving so 34 00:04:01,430 --> 00:04:03,430 and living things need to adapt to the flow. 35 00:04:04,870 --> 00:04:06,469 We can also find lakes. 36 00:04:06,469 --> 00:04:08,949 In lakes, water doesn't really move, 37 00:04:08,949 --> 00:04:11,310 so some plants can grow here, 38 00:04:11,310 --> 00:04:14,289 and those plants provide shelter for birds 39 00:04:14,289 --> 00:04:15,750 and other little animals. 40 00:04:17,389 --> 00:04:21,009 And now we have a general idea of what ecosystems are.