Science 2200 Unit One Ecosystems Final Presentation Sections 1.17 –1.18 Science 2200

1.17 Logging Forests Importance of the Forest Forests are an important resource that  allows life to continue on Earth. It is through our forests that water and carbon dioxide gets recycled and this in turn regulates climate. Science 2200

Trees are constantly absorbing water from the ground and releasing it into the atmosphere. Trees also act as a filter by taking in carbon dioxide and releasing oxygen. Science 2200

In addition, forests act as a giant sponge, slowing runoff and holding groundwater. Science 2200

Their root systems  prevent soil erosion and of course forests  provide shelter and homes for many species of animals . Science 2200

Historical Background For the first 400 years: of settlement in Newfoundland and Labrador, traditional use of our forest resource centered around cutting timber for shelter, fuel and construction of boats, stages, and flakes. Science 2200

Science 2200

During most of the last 100 years; forest management in our province centered around  the development of a forest industry Since the mid 1970’s, management of the forest resource has shifted to intensive timber management improved protection from insects and fire more efficient use of the timbre resource. Science 2200

During the 1990’s..... another shift in thinking (paradigm shift!) is taking place which is management of the forest as an ecosystem. Science 2200

Forestry Practices In Canada forests impacted by humans; temperate deciduous forest and boreal forest biomes. This human intervention has been mainly in the form of logging. Science 2200

Logging or the harvesting of the forest occurs in two main ways: Clear-cutting Selective Cutting Science 2200

Clear-cutting all trees in a large area are removed for timber or pulp industries very controversial method It is considered the most efficient and economical method of tree harvesting because it requires less road construction Science 2200

loggers say that it most closely resembles the natural replacement of a forest after a fire, as it allows the forest to regenerate with new, healthy trees. However, logging companies usually only replant trees that are valuable to them (eg. spruce and fir) Science 2200

Science 2200

Such a forest is very susceptible to insect and pest damage. This produces a forest with a much lower biodiversity than a natural forest. Such a forest is very susceptible to insect and pest damage. In Newfoundland and Labrador, about 90% of the commercially logged areas are clear-cut. Science 2200

Clear-cutting impacts many native species Temperature increase-removing trees results in exposing the dark ground which will heat up thus increasing the temperature in summer. Also, in the winter, the opposite will occur and the soil will become much cooler Science 2200

When the trees are gone, soil erosion occurs Water loss- Trees act like sponges slowing run-off and holding ground water as well as preventing soil erosion. When the trees are gone, soil erosion occurs Science 2200

Also, eroded soil causes streams to clog which can result in water loss from a pond ecosystem. Science 2200

Food web disruption- Trees provide shelter, food and protection to many animals that live in the forest ecosystem A loss of trees will impact all species that depend upon tree dwelling species! Science 2200

Science 2200

For example, snowshoe hares feed on a variety of trees and shrubs, in clear-cuts areas, loss of vegetation will result in a loss of snowshoe hares carnivores such as lynx, coyotes, owls depend on hares as a food source. Science 2200

Habitat Loss- Removing trees results in destroying natural” real estate” for animals. Nesting site loss: clear-cutting encourages animal species that prefer open, shrubby habitats, (moose, fox, grouse) it still destroys the homes of squirrels, pine martins, and hundreds birds species such as the northern spotted owl. Science 2200

northern spotted owl Science 2200

                                                                    Science 2200

Science 2200

Selective Cutting: only certain trees from an area are harvested usually the most valuable and largest trees that make good lumber and pulp. In this method only the best trees are cut from an area. Science 2200

Advantage of Selective Cutting: offers better protection from soil erosion, minimizes disturbances in environmentally sensitive areas, provides more diversity to wildlife habitat more aesthetically pleasing than clear-cuts. Science 2200

Understanding Concepts 1. They are the lungs of the earth, regulate climate by recycling CO2 H2O via photosynthesis Forests slow runoff and hold groundwater Roots protect soil Decomposing trees provide nutrients for the soil Science 2200

1.18 Acid Precipitation Acidity. is measured using a pH scale, with the number 7 in the middle being neutral. Consequently, a substance with a pH value of less than 7 is acidic, while a value greater than 7 is basic. Science 2200

The pH of 5.6 has been used as the baseline in identifying acid precipitation. Therefore acid rain is defined as any rainfall that has an acidity level (pH value) of less than 5.6 Science 2200

Causes of Acid Precipitation #1.Sulfur Dioxide Gas (SO2) is one of the main causes of acid rain. Natural sources, which produce this gas, are volcanoes, sea spray, rotting vegetation and plankton. Science 2200

However, the burning of fossil fuels, (coal and oil,) are to be blamed for approximately half of the global emissions of this gas When sulfur dioxide reaches the atmosphere, it  becomes sulfuric acid as it joins with hydrogen atoms and falls as acid rain Science 2200

#2.Nitrogen Oxide is a component of acid rain. Its sources are mainly from power stations and exhaust fumes. Like sulfur dioxide, nitrogen oxide rises into the atmosphere and  forms nitric acid. Science 2200

In 1995, Canada’s largest contributor of nitrogen oxide was from the transportation sector.  Science 2200

More than half of the acid deposition in eastern Canada originates from emissions in the United States. Only reducing acidic emissions in both Canada and the U.S. will significantly reduce acid rain. Science 2200

Science 2200

Effect on Lakes and Aquatic Ecosystems One of the direct effects of acid rain is on lakes and its aquatic ecosystems. There are many ways in which acidic chemicals can enter lakes: Science 2200

Some chemicals enter the lakes as rain, sleet, hail, snow, dew or fog. Acid rain that falls onto Earth washes the nutrients out of the soil and carries toxic metals that have been released from the soil into the lakes. Science 2200

Effect on Humans Sulfur dioxide and nitrogen oxide emissions give rise to respiratory problems such as asthma, dry coughs, and throat irritations Science 2200

A indirect effect of acid precipitation is that the toxic metals dissolved in the water are absorbed in fruits, vegetables and in the tissues of animals. these metals do not directly affect the animals, but they have serious effects on humans when they are being consumed. Science 2200

eg, mercury has been linked with brain damage in children as well as nerve disorders Similarly, aluminum, has been associated with kidney problems and recently, was related to Alzheimer's disease. Science 2200

The three main sources of acid deposition are: Use of coal in the production of electricity Base metal smelting Fuel combustion in vehicles Science 2200

Reducing Sulfur Dioxide Emissions: In Automobiles Science 2200

Automobiles today have catalytic converters that reduce nitrogen oxide but there are more and more people using automobiles With more automobiles being used, more pollutants are entering the environment. Science 2200

There are many things, which you can do in order to help reduce acid rain emissions. Science 2200

Install a low-flow showerhead. Run the dishwasher or washing machine only with a full load. If using an automatic dishwasher let the dishes air dry. Science 2200

Buy energy-efficient appliances. Hang dry the laundry. Buy energy-efficient appliances. Avoid the use of air conditioners altogether. Turn out the lights in empty rooms and when away from home. Science 2200

Install additional insulation on the hot water tank and pipes. install compact fluorescent bulbs instead of high-wattage incandescent bulbs. Turn off the hot water tank when going away for extended periods of time. Install additional insulation on the hot water tank and pipes. Science 2200

Insulate and draft-proof your basement. Weather-strip doors and windows. Turn down the heat at night and when away from home. change or clean furnace filters at least once a year. Don’t use sink garbage disposal units. Science 2200

In the Yard Consider changing to a low-maintenance landscape. If you have a pool, keep a thermal insulating cover over it when you are not using it. Science 2200

Transportation Walk, ride your bike or take a bus to work. Share a ride with a friend or co-worker. Have your engine tuned at least once every six months.  Science 2200

Transportation Check your car tire pressure regularly. Use alternative fuels, such as ethanol, propane or natural gas. Avoid unnecessary idling.  Science 2200

Transportation. In winter, use a block heater for only two to three hours prior to driving, rather than overnight. Reduce the number of trips you make in your car. Drive at moderate or lower speeds. Take the train or bus on long trips. Science 2200

Understanding Concepts 1. Oxides of sulphur and nitrogen enter the atmosphere and combine with water droplets to form acids. These acidic droplets act like normal water droplets in the water cycle they eventually fall as rain snow, fog, and ice. Science 2200

Understanding Concepts 2. Fossil fuel burning electrical generating stations, industrial processes refineries, furnaces, automobiles etc. Science 2200

Understanding Concepts 3 Kills nitrogen fixing bacteria and increase the concentration of aluminum in the soil which interferes with nutrient absorption by root systems Science 2200

Understanding Concepts 4 See diagram Science 2200