Documents

Fire

Description
Description:
Categories
Published
of 4
4
Categories
Published
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Share
Transcript
  WHAT IS FIRE? - Fire is the rapid oxidation of a material in the exothermic chemical process of combustion, releasing heat, light, and various reaction products. - Fire in its most common form can result in conflagration, which has the potential to cause physical damage through  burning. Fire is an important process that affects ecological systems around the globe. POSITIVE EFFECTS OF FIRE Fire is often associated with negative impacts on the environment. We usually think of the damage and devastation fire causes to wildlife and vegetation, but a fire event can also be beneficial for our plants and animals. For example, fire:    heats the soil, cracking seed coats and triggering germination    triggers woody seed pods held in the canopy to open, releasing seed onto a fresh and fertile ash bed    clears thick understory reducing competition for seedlings    understory comprises plant life growing beneath the forest canopy without penetrating it to any great extent,  but above the forest floor.    encourages new growth that provides food for many animals    creates hollows in logs and trees that can be used by animals for nesting and shelter. NEGATIVE EFFECTS OF FIRE Fire can also:     burn and damage vegetation communities, such as rainforest that take hundreds of years to recover o   also, when vegetation is burned, the nitrogen it contains is released into the atmosphere, unlike elements such as potassium and phosphorus which remain in the ash and are quickly recycled into the soil. This loss of nitrogen caused by a fire produces a long-term reduction in the fertility of the soil, which only slowly recovers as nitrogen is fixed from the atmosphere by lightning and by leguminous plants such as clover.    kill or injure individual plants or animals o   Fire can have an impact on native animals through injury and loss of habitat. o   In most cases, populations will not be affected because native animals from surrounding areas will recolonize a burnt area after a fire. When the distribution of a species is limited, or the species is listed as vulnerable or endangered, a significant fire event can impact these populations. o    Native animals can escape fire by fleeing to ‘unburnt islands’ within a burn area or to surrounding unburnt vegetation. Insects, reptiles and small mammals may be able to hide underground, and animals that live in trees can move to treetops and escape low-to-moderate intensity fires. o   Birds are least impacted by fire as they can fly away, but chicks and eggs can be impacted depending upon the season of the fire.    cause erosion and subsequent sedimentation of creeks and wetlands o   if fire removes protective vegetation, heavy rainfall may lead to an increase in soil erosion by water.    open up areas to the impacts of weed and feral animal invasion as well as human access and vandalism.  BIOTIC RESPONSES AND ADAPTATIONS PLANT ADAPTATIONS TO FIRE Unlike animals, plants are not able to move physically during a fire. However, plants have their own ways to survive a fire event or recover after a fire. The strategies can be classified into three types: resist (above-ground parts survive fire), recover (evade mortality by sprouting), and recruit (seed germination after fire). Fire plays a role as a filter which can select for different fire response traits. ANIMALS' ADAPTATIONS TO FIRES DIRECT EFFECTS OF FIRES ON ANIMALS Most animals have sufficient mobility to successfully evade fires. Vertebrates such as large mammals and adult birds are usually capable of escaping from fires. However, young animals which lack mobility may suffer from fires and have high mortality. Ground-dwelling invertebrates are less impacted by fires (due to low thermal diffusivity of soil) while tree-living invertebrates may be killed by crown fires but survive during surface fires. Seldom, animals are directly killed by fires. LONG TERM EFFECTS OF FIRES ON ANIMALS More importantly, fires have long-term effects on the post-burn environment. Fires in seldom-burned rainforests can cause disasters. For example, El Niño-induced surface fires in central Brazilian Amazonia have seriously affected the habitats of  birds and primates. Fires also make animals exposed to dangers such as humans or predators. Generally in a habitat  previously with more understory species and less open site species, a fire may replace the fauna structure with more open species and much less understory species. However, the habitat normally will recover to the srcinal structure. LEVELS OF FIRE Fire can burn at three levels. 1. Ground fires will burn through soil that is rich in organic matter. 2. Surface fires will burn through dead plant material that is lying on the ground. 3. Crown fires will burn in the tops of shrubs and trees.    WHAT IS WATER? - Water is a transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's streams, lakes, and oceans, and the fluids of most living organisms. It is vital for all known forms of life, even though it provides no calories or organic nutrients. -Water covers 71% of the Earth's surface, mostly in seas and oceans. Small portions of water occur as groundwater (1.7%), in the glaciers and the ice caps of Antarctica and Greenland (1.7%), and in the air as vapor, clouds (formed of ice and liquid water suspended in air), and precipitation (0.001%). WATER RESOURCES - Water resources are sources that humans use. Some uses of water are: agricultural, industrial, household, recreational and environmental activities. On earth is a 97% of salt water and the 3% is fresh water. - FRESH WATER is a renewable resource but it is decreasing. Water demand has exceeded the freshwater supply and its renewability cannot keep up in many parts of the world especially the third world nations. This is also further worsened by the world population continuing to rise. EFFECTS ON LIFE    From a biological standpoint, water has many distinct properties that are critical for the proliferation of life. It carries out this role by allowing organic compounds to react in ways that ultimately allow replication. All known forms of life depend on water. Water is vital both as a solvent in which many of the body's solutes dissolve and as an essential part of many metabolic processes within the body. Metabolism is the sum total of anabolism and catabolism. In anabolism, water is removed from molecules in order to grow larger molecules (e.g. starches, triglycerides and proteins for storage of fuels and information). In catabolism, water is used to break bonds in order to generate smaller molecules (e.g. glucose, fatty acids and amino acids to be used for fuels for energy use or other purposes). Without water, these particular metabolic processes could not exist.    Water is fundamental to photosynthesis and respiration. Photosynthetic cells use the sun's energy to split off water's hydrogen from oxygen. Hydrogen is combined with CO2 (absorbed from air or water) to form glucose and release oxygen. All living cells use such fuels and oxidize the hydrogen and carbon to capture the sun's energy and reform water and CO2 in the process (cellular respiration).    Water is also central to acid-base neutrality and enzyme function. An acid, a hydrogen ion (H + , that is, a proton) donor, can be neutralized by a base, a proton acceptor such as a hydroxide ion (OH − ) to form water. Water is considered to be neutral, with a pH (the negative log of the hydrogen ion concentration) of 7. Acids have pH values less than 7 while bases have values greater than 7.    Earth surface waters are filled with life. The earliest life forms appeared in water; nearly all fish live exclusively in water, and there are many types of marine mammals, such as dolphins and whales. Some kinds of animals, such as amphibians, spend portions of their lives in water and portions on land. Plants such as kelp and algae grow in the water and are the basis for some underwater ecosystems. Plankton is generally the foundation of the ocean food chain.     Aquatic vertebrates must obtain oxygen to survive, and they do so in various ways. Fish have gills instead of lungs, although some species of fish, such as the lungfish, have both. Marine mammals, such as dolphins, whales, otters, and seals need to surface periodically to breathe air. Some amphibians are able to absorb oxygen through their skin. Invertebrates exhibit a wide range of modifications to survive in poorly oxygenated waters including  breathing tubes (insect and mollusk siphons) and gills (Carcinus crabs). However as invertebrate life evolved in an aquatic habitat most have little or no specialization for respiration in water. WATER SCARCITY - Water scarcity is the lack of fresh water resources to meet water demand. It affects every continent and was listed in 2019 by the World Economic Forum as one of the largest global risks in terms of potential impact over the next decade. - The essence of global water scarcity is the geographic and temporal mismatch between freshwater demand and availability. The increasing world population, improving living standards, changing consumption patterns, and expansion of irrigated agriculture are the main driving forces for the rising global demand for water. Climate change, such as altered weather-patterns (including droughts or floods), deforestation, increased pollution, greenhouse gases, and wasteful use of water can cause insufficient supply. EFFECT ON ENVIRONMENT - Water scarcity has many negative impacts on the environment, including lakes, rivers, wetlands and other fresh water resources. The resulting water overuse that is related to water scarcity, often located in areas of irrigation agriculture, harms the environment in several ways including increased salinity, nutrient pollution, and the loss of floodplains and wetlands. Furthermore, water scarcity makes flow management in the rehabilitation of urban streams problematic. - Subsidence, or the gradual sinking of landforms, is another result of water scarcity. - Through the last hundred years, more than half of the Earth's wetlands have been destroyed and have disappeared. These wetlands are important not only because they are the habitats of numerous inhabitants such as mammals, birds, fish, amphibians, and invertebrates, but they support the growing of rice and other food crops as well as provide water filtration and protection from storms and flooding. - Apart from the conventional surface water sources of freshwater such as rivers and lakes, other resources of freshwater such as groundwater and glaciers have become more developed sources of freshwater, becoming the main source of clean water. Groundwater is water that has pooled below the surface of the Earth and can provide a usable quantity of water through springs or wells. These areas where groundwater is collected are also known as aquifers. Glaciers provide freshwater in the form meltwater, or freshwater melted from snow or ice that supply streams or springs as temperatures rise. More and more of these sources are being drawn upon as conventional sources' usability decreases due to factors such as pollution or disappearance due to climate changes. Human population growth is a significant contributing factor in the increasing use of these types of water resources - Another popular opinion is that the amount of available freshwater is decreasing because of climate change. Climate change has caused receding glaciers, reduced stream and river flow, and shrinking lakes and ponds. Many aquifers have  been over-pumped and are not recharging quickly. Although the total fresh water supply is not used up, much has become  polluted, salted, unsuitable or otherwise unavailable for drinking, industry and agriculture. To avoid a global water crisis, farmers will have to strive to increase productivity to meet growing demands for food, while industry and cities find ways to use water more efficiently. WATER CONSERVATION - Water conservation is the practice of using water efficiently to reduce unnecessary water usage. Water conservation is important because fresh clean water is a limited resource, as well as a costly one. Ways to save water 1. Check your toilet for leaks Put a few drops of food coloring in your toilet tank. If, without flushing, the coloring begins to appear in the bowl, you have a leak that may be wasting more than 100 gallons of water a day. 2. Stop using your toilet as an ashtray or wastebasket Every cigarette butt or tissue you flush away also flushes away five to seven gallons of water. 3. Put a plastic bottle in your toilet tank Put an inch or two of sand or pebbles in the bottom of a one liter bottle to weigh it down. Fill the rest of the bottle with water and put it in your toilet tank, safely away from the operating mechanism. In an average home, the bottle may save five gallons or more of water every day without harming the efficiency of the toilet. If your tank is big enough, you may even be able to put in two bottles. 4. Take shorter showers or take a bath instead. A typical shower uses five to ten gallons of water a minute. Limit your showers to the time it takes to soap up, wash down and rise off. A partially filled tub uses less water than all but the shortest showers.  5. Install water-saving shower heads or flow restrictors Your hardware or plumbing supply store stocks inexpensive shower heads or flow restrictors that will cut your shower flow to about three gallons a minute instead of five to ten. They are easy to install, and your showers will still be cleansing and refreshing. 6. Turn off the water while brushing your teeth Before brushing, wet your brush and fill a glass for rinsing your mouth. 7. Turn off the water while cleaning vegetables Rinse your vegetables instead in a bowl or sink full of clean water. 8. Check faucets and pipes for leaks Even a small drip can waste 50 or more gallons of water a day. 9. Use your automatic dishwasher for full loads only Every time you run your dishwasher, you use about 25 gallons of water. 10. Use your automatic washing machine only for full loads only Your automatic washer uses 30 to 35 gallons per cycle. 11. Don't let the faucet run while you clean vegetables Rinse your vegetables instead in a bowl or sink full of clean water. 12. Keep a bottle of drinking water in the refrigerator This puts a stop to the wasteful practice of running tap water to cool it for drinking. 13. If you wash dishes by hand, don't leave the water running for rinsing If you have two sinks, fill one with rinse water. If you have only one sink, first gather all your washed dishes in a dish rack, then rinse them quickly with a spray device or a pan of water. 14. Plant drought-resistant trees and plants Many beautiful trees and plants thrive without irrigation. 15. Put a layer of mulch around trees and plants. Mulch slows the evaporation of moisture.

Rdgv 15 02 e

Sep 22, 2019
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks
SAVE OUR EARTH

We need your sign to support Project to invent "SMART AND CONTROLLABLE REFLECTIVE BALLOONS" to cover the Sun and Save Our Earth.

More details...

Sign Now!

We are very appreciated for your Prompt Action!

x