This presentation will focus on wetland ecosystems and the many services that they provide. It will discuss the current extent of wetlands and

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2 This presentation will focus on wetland ecosystems and the many services that they provide. It will discuss the current extent of wetlands and mangroves around the world, define what an ecosystem service is, and then present the five types of ecosystem services that these wetlands and mangroves provide to human populations. These ecosystems services include: supporting, biological, provisioning, regulating, and cultural services. Examples of each ecosystem service will also be presented. 2

3 The area of wetlands and mangroves in the world is relatively low; it is less than 10% of the total land area. That would be equivalent to the area that my hands provide compared to my entire body. Despite their small area, mangroves and wetlands provide many benefits for human populations. Scientists refer to these benefits as ECOSYSTEM SERVICES. 3

4 What s an ecosystem service? We all know what a service is. For example, if you are riding your scooter and your front wheel falls off, you take it to a mechanic who provides you with a service that you pay for. 4

5 He fixes the wheel and your scooter! 5

6 Another example would be a merchant selling vegetables at a market. You pay him for a service, to provide you with fresh vegetables. 6

7 Ecosystem services are free resources and processes provided by natural ecosystems that benefit humans. Different types of ecosystems provide different sets of services. 7

8 Mangroves provide us with many supporting, biological, provisional, regulatory, and cultural ecosystem services (Ewel et al., 1998, Duke et al., 2007). 8

9 Supporting ecosystem services are the services that occur within the ecosystem that support tropical wetlands. For example, growth of wetland trees and plants would be considered a supporting service. As trees grow, they remove excess carbon dioxide from the air and 9

10 remove pollution from the water. The trees become bigger and make more trees, creating a mangrove forest. All of these trees provide food for shrimp, fish, birds, and other animals. If the trees didn t grow, there wouldn t be a mangrove and there wouldn t be any other benefits provided! Copyright 1998 Bioinformatics Centre, National Institute of Oceanography, Dona Paula, Goa, India angroves/mangcd/fact.htm 9

11 Wetlands provide biological services by supporting many SPECIES of plants, birds, fish, and mammals (Tomlinson 1986; Nagelkerken et al. 2008). This is called biodiversity. Southeast Asian peatlands alone support over 6000 kinds of plants and animals! The 10

12 type of plants found in forested wetlands are influenced by different factors, such as the amount of salt in the water (Tomlinson 1986). For example, Sonneratia species of mangroves can grow very well in salty water, while Nypa palm trees cannot and prefer to grow in freshwater. As a result, areas within wetlands often only support one or two kinds of species of plant or tree. When we consider the entire wetland, there are many more numbers of species present. The plants found in wetlands have unique features they can grow in areas that are flooded with water at least 2 times a day; they can live in areas where 10

13 the sediment has no air in it for the plant roots to breath, and can grow in water that is very salty (Tomlinson 1986). 10

14 The roots of mangrove trees demonstrate why these trees are so unique. There are tiny holes in these roots that let air move down into the sediments so that the underground roots can breathe! These roots also make the mud in the mangroves more stabile so that 11

15 the trees can grow taller. This is an example of a plant species, Rhizophora apiculata, that grows in the mangroves. The roots growing off of this tree are called prop roots. 11

16 Another biological service that tropical wetlands provide is that they provide areas for fish, shrimp, and crabs. When the wetlands and mangroves are flooded with water, fish, shrimp, and crabs can swim into the mangroves (Primavera 1998; MacKenzie and Dionne, 12

17 2008). Why? For several reasons. 12

18 Fish must avoid being eaten by larger fish. Smaller fish can hide from larger fish by swimming into the roots of the mangroves trees. Different types of roots appear to provide different levels of protection. Smaller spaces within pneumatophores and knee roots 13

19 provide excellent hiding places for small fish. Prop roots also provide hiding places, but can also allow larger fish to get access to these places (MacKenzie and Cormier 2012). 13

20 Many of these fish use the mangroves when they are babies and as they grow bigger, they swim out into deeper areas of the ocean or onto coral reefs. This is depicted here in this slide. Scientists found that certain coral reef fish, such as the snapper fish (gray and black) 14

21 and the parrot fish (orange and green), will lay their eggs in sea grass beds. When the eggs hatch, the babies swim into the nearby mangroves (top picture), where they eat and grow into larger fish. Once they are too big to be eaten by bigger fish, they slowly swim back to the reef where they grow into adults and reproduce, and then the whole life cycle starts over again. The scientists also found in this study that there were fewer numbers of these fish species in coral reef areas where there were no mangroves or where the mangroves had been cut down. 14

22 Another reason fish, shrimp and crabs swim into flooded wetlands is to eat (Morineiere et al. 2003; Benstead et al. 2006)! Plants provide food for many species of shrimp, fish and crabs that live in the mangroves and in areas of the ocean next to the mangroves. For 15

23 example, if you have ever walked into a mangrove, you may notice that, unlike the upland forests, there are not many leaves on the mangrove forest floor. This is because the leaves that fall from the mangrove trees are quickly eaten by crabs, shrimp and some fish. FAO Mangrove forest management guidelines. FAO Forestry Paper No Rome 15

24 These small crabs and shrimps are then eaten by larger fish and birds (Nagelekerken et al., 2008; Primavera, 1997). FAO Mangrove forest management guidelines. FAO Forestry Paper No Rome 16

25 and other animals such as monkeys, crocodiles, or tigers that live in the mangroves or that swim into the mangroves from the ocean during high tides (Nagelkerken et al., 2008). Leaves are an important food for small crabs and shrimps (Lee 1998). Because these animals 17

26 are then eaten by larger animals, leaves are thought to be the foundation of the mangroves. 17

27 Provisioning ecosystem services are any product that can be harvested from a tropical wetland that benefits local people (Bennett et al. 2009). This includes any animals or plants that are harvested to be eaten, plants that are used for thatch or wood posts 18

28 in homes, wood used as fuelwood, or plants used as medicine to treat various kinds of illness. 18

29 A study conducted on the island of Kosrae revealed that half of the annual household incomes came from products harvested from the mangroves. Half of that income came from the sale of mangrove crabs (Sylla serrata), while the rest came from the sale of firewood 19

30 and fish. 19

31 Wetlands provide many services that make it possible for humans to exist on the planet, these are known as regulating services (Carpenter et al., 2012). Regulating services include cleaning water through the removal of pollution or soil. The plants growing in the 20

32 wetlands also provide clean air for us to breath. 20

33 A well known regulating service that wetlands provide is their ability to provide protection from storms and tsunamis. When large waves from storms flow into the mangroves, mangrove trees and roots create barriers that waves must flow through as the waves 21

34 move through the forest floor. These barriers cause the waves to slow down, reducing their height and their destructive power (top picture). Higher numbers (densities) of healthy trees are much more capable of slowing down waves than lower numbers of healthy trees or unhealthy or dead trees (lower picture). A recent study led by TNC and Mangrove International revealed that mangroves can reduce the height of wind and swell waves over relatively short distances; wave height can be reduced by between 13 and 66% over 100 meters of mangroves. The rate of 21

35 wave height reduction per unit of distance is affected by the type and condition of the mangroves present and their basal area (McIvor et al. 2012). 21

36 Wetlands can also provide us with clean water by trapping soil or sediment that pass through them or by removing pollution. As water moves through wetlands or mangroves, the plants slow the water movement such that any suspended particles are deposited 22

37 on the wetland/mangrove surface. Similarly, plant and tree growth can remove any excess nutrients that are in the water that flows through them. This provides humans with clean drinking water as well as protecting coral reefs and the ocean. Unfortunately, too much of a good thing can be bad. Too many nutrients or too much sediment can have negative impacts on wetlands by degrading water quality or smothering plants. 22

38 Tropical forested wetlands can also store A LOT of carbon as aboveground carbon pools in the form of trunks and branches and as belowground carbon pools in the form of roots. Despite the fact that Southeast Asian swamps represent only 6 7% of global peatland, they 23

39 store 69 billion metric tonnes of carbon (Alongi 2012; Kauffman and Donato 2012). 23

40 This graph shows how aboveground and belowground carbon stores compare across different forest types. The y axis represents the amount of carbon stored (ecosystem C storage) while the x axis represents the different types of forests. The white shaded 24

41 area of the bars represent the aboveground C stores, such as trunks, branches, and leaves, while the gray shaded areas represent belowground c stores (roots, sediment). As you can see, most of the carbon in mangroves and tropical peatland swamps is stored belowground. Why? 24

42 If we look more closely at the sediments, we see that the carbon is stored as small roots or pieces of sediment. The spaces between these pieces of sediment and roots are full of water; there is little or no oxygen in these spaces. As a result, small animals and bacteria 25

43 cannot feed on the sediments and roots and the carbon is somewhat permanently buried (Tomlinson 1986). 25

44 Finally, wetlands provide us with many cultural services (Carpenter et al., 2009). These are services that benefit the cultural advancement, the mind and the spirit of human beings. For example, the trees, birds, and fish can inspire traditional cultural 26

45 songs, dances or art that is passed down from generation to generation. 26

46 Many people find it very calming and relaxing after a busy day in the office to float through the creeks of a beautiful intact mangrove. Many people also prefer to look at the natural coastline and the giant mangrove trees and birds that they support, as opposed to looking at a 27

47 coastline that has been cleared, that is full of aquaculture ponds, or hotels. These cultural services are known as aesthetic, recreational or ecotourism services. 27

48 Wetlands are important ecosystems that provide a variety of valuable ecosystems services to the human populations that rely on them. These services include many different kinds of supporting, biological, provisioning, regulatory, and cultural services. This 28

49 underscores the importance of wetlands and the need to protect and conserve wetlands around the globe. While wetland restoration is also a much needed and important approach to wetland conservation, prevention of wetland loss is the best strategy to protect wetlands and maintain the many services that they provide. 28

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