ANOTHER BEAUTIFUL POWERPOINT BY PATRICK

SOPKO.Lucky you. It is about wetlands.

Soil.

Wetlands exist in areas where the soil is saturated (full of water) for most of the year. The reasons that the soil is saturated vary. The wetland may be on the edge of a lake or pond with vegetation growing out of the water and in soils at the lake margins. The lake level determines the location of the wetland by controlling where the zone of soil saturation exists. Alternatively the wetland may be in a depression so that water cannot easily escape and the soil remains saturated. Wetlands also occur in locations of groundwater upwelling. The water table is the upper boundary of groundwater. Where groundwater flows upwards from a groundwater source, like a spring, soils become waterlogged. This requires that the wetland not be on a steep slope so that the water cannot run off easily.

Hydrology.

Humans have altered wetland hydrology through a variety of activities: drainage, filling, damn construction, water diversions, groundwater pumping, and dredging (Zedler, 2000). All of these activities alter the timing, amplitude, frequency, and duration of high water (Zedler, 2000). Today, wetland scientists are aware of the importance of hydrology. Despite all the "hype" that wetland hydrology has received, we still know very little about how to manipulate or simulate certain hydrological conditions. However, the future is getting brighter. Many restorationists are manipulating hydrological variables in their restoration restoration projects (see Case studies). It is important that long term monitoring of hydrologic variables including, groundwater flow, surface water recharge, water level fluctuation, and precipitation input, and others, are recorded. After long-term hydrological data is available, restoring wetland hydrology will become "easier" and a more attainable goal.

Mini-Case study

Vegetation.

The wetland vegetation described here is grouped into four general ecological categories, depending mainly on growth position in relation to water level (Whitley et al. 1999). Of course, water levels tend to vary in wetlands on seasonal and interannual time periods according to climatic conditions and human management. While some wetland plants can tolerate substantial variations in soil moisture and water level, others have strict water requirements for survival. Thus, the following groups represent only a rough guide to typical wetland plant habitats.

Shoreline: plants that grow in wet soil on raised hummocks or along the shorelines of streams, ponds, bogs, marshes, and lakes. These plants grow at or above the level of standing water; some may be rooted in shallow water.

Emergent: plants that are rooted in soil that is underwater most of the time. These plants grow up through the water, so that stems, leaves and flowers emerge in air above water level.

Floating: plants whose leaves mainly float on the water surface. Much of the plant body is underwater and may or may not be rooted in the substrate. Only small portions, namely flowers, rise above water level.

Submerged: plants that are largely underwater with few floating or emergent leaves. Flowers may emerge (briefly) in some cases for pollination.

The following plant descriptions are based on Whitley et al. (1999), as well as other sources as noted. Ink-sketch illustrations of many typical wetland plants by Haefner (in Whitley et al. 1999) are provided in a separate handout package. All photographs below © by J.S. Aber.

Shoreline plants

Bogs

Riverbanks, floodplains elevated only a few feet above river level, abandoned river channels, and oxbow lakes may have standing or sluggishly flowing water for much of the year and thus support swamps and marshes. Many trees can survive and even thrive in freshwater swamps as long as their roots are not submerged in water for long periods of time.

Marsh

Freshwater marshes are often found in open areas near rivers and lakes. They are very common at the mouths of rivers and form in areas with mineral soil that drains very slowly. The water in freshwater marshes is usually one to six feet deep and is rich in minerals. Water flows into marshes from rain or from a water source like creeks, streams, or rivers.

Swamps

A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation.[1] The two main types of swamp are "true" or swamp forests and "transitional" or shrub swamps. The water of a swamp may be fresh water, brackish water or seawater.

In North America, swamps are usually regarded as including a large amount of woody vegetation, but elsewhere this may not necessarily apply, such as in African swamps dominated by papyrus. By contrast, a marsh in North America is a wetland without woody vegetation, or elsewhere, a wetland without woody vegetation which is shallower and has less open water surface than a swamp. A mire (or quagmire) is a low-lying wetland of deep, soft soil or mud that sinks underfoot with large algae covering the water's surface.

Functions and Values of Wetlands.

Wetlands perform a dazzling array of ecological functions that we have only recently begun to appreciate. A century ago the president of the American Health Association promoted the idea of a national campaign to eliminate wetlands. Today, scientists recognize the environmental benefits that wetlands provide, and they are now alerting us to the importance of preserving rather than eliminating our wetland resources. Your wetland is likely performing vital ecological functions that were barely recognized a few short years ago.

Even now our understanding of the complexities of wetland ecosystems is still developing, and it seems the more we learn, the more valuable wetlands become. Wetland ecologists have already documented the following environmental benefits of wetlands: water purification, flood protection, shoreline stabilization, groundwater recharge, and streamflow maintenance. Wetlands also provide habitat for fish and wildlife, including endangered species. Not all wetlands provide all of these benefits, and how your particular wetland works depends on its location and its type. What follows is a simple summary of how wetlands perform their complicated functions, along with a brief explanation of how these functions support humans and other species.

Wetlands ARE important to all organisms.

Wetlands are special ecosystems where water and land meet, making “wet land.” The scientific definition is that water covers the soil or is present at or near the surface of the land for the majority of the year. There are many different kinds of wetlands, and wetlands can be found on all the continents except Antarctica. While wetlands share the basic definition around the globe, the specific ecology of wetlands varies in different parts of he world, and even in wetlands that are relatively close to each other.

There are two major types of wetlands: coastal and inland. These are also sometimes called tidal and non-tidal. Inland wetlands are created from freshwater, and are often seasonal. Swamps, bogs, and fens are examples of the variety of types of inland wetlands, and these, like coastal wetlands, can be found across the country and around the world. Estuaries are a special sub-category of coastal wetlands, where fresh water and salt water mix in the wetland, making a habitat of varying salinity.

Estuaries and coastal wetlands are particularly important for the success of ocean fish, because many of these fish lay their eggs in the coastal wetlands. When wetlands are threatened, many fish that spend the majority of their adult life at sea can also be threatened because they have nowhere to lay eggs, and nowhere for the juvenille fish to safely reach adulthood. This makes wetland protection important to the success of the worldwide fishing and shrimping industries.

In North America, there are wetlands from coast to coast in states like California and North Carolina, and from north to south including Alaska and Texas. The temperate zone wetlands are essential to bird migrations, providing resting stops for the long trek between the tropics and the tundra. At these rest stops, the birds can find shelter in the plants growing in the wetlands, and can find plenty of food in the sea animals that live in the water and earth.

A special kind of wetland found in the tropics around the world is the mangrove, which provides shelter to many kinds of tropical marine life. The roots of the mangrove trees grow in and out of the water, making a forest of roots where the marine animals can hide. The leaves and stems from the mangrove trees fall into the water, becoming detritus for small marine creatures to eat, forming the base of the food web.

Detritus is common to all water ecosystems, and all the plants in the wetlands provide material for the so-called “bottom feeders” that consume mostly this decaying plant matter, and which are also lowest on the food chain. The insects, small fish, shellfish, and especially juvenile fish that feed on detritus from the wetland plants become the food for the animals higher up in the food chain, like larger fish, amphibians, reptiles, birds, and in some locations even mammals.

Wetlands are also particularly productive ecosystems. This means that energy and nutrients turn over faster in wetlands than in other ecosystems. Rainforests and coral reefs are other productive systems. Productive ecosystems help sequester carbon by providing fast-growing plants to hold carbon in their matter. These ecosystems can often successfully process toxins because of the fast growth rate, naturally cleaning the water and land. In coastal estuaries this is particularly important because the fresh water has collected pollutants on its journey to the sea.

In addition to cleaning our water, wetlands also provide other important benefits to humans. Wetlands offer flood protection in all regions. The wetlands are like natural sponges that can absorb immense amounts of water in a short amount of time. In coastal zones wetlands provide hurricane protection by creating a buffer zone between the water and the land.

Yeayaaaa.

Just another one of my AMAZING powerpoints. Lucky you.