What Is Ecological Footprint - Essay Example

UNIT ASSIGNMENT INTRODUCTION I am a visual sequential learner. I remember and assimilate information when I read. 2. I ensure that my basics are clear before I go on to the more complicated and inter-related topics. CHAPTER 1: 1. ‘Ecological footprint’ is a measure of the demand/pressure that each individual imposes on the environment A person living in Africa would probably even today recycle and reuse products, grow own food and spend less on processed foods, travel less, live in smaller houses and share space with more people, generally live a life that is less dependent on fossil fuels and non-renewable resources. 2. To live sustainably one must adopt a lifestyle that is simple, energy efficient, reduces waste and imposes the least possible negative impact on the environment. 3. The quality of our life depends on the physical (pure air, water, soil), biological (diversity in plant and animal species) and social attributes (health, working conditions, economic activities) of the environment we live in. CHAPTER 2: 1. The first step is identifying that there is no water supply. The next step is to see the possible causes – leakage/block in pipeline connected to this faucet; damage/clog in the main pipeline supplying water to the house; check for reports in press and media about possible maintenance work by water supply department or break down in power supply, contamination at the source of water supply, higher incidence of water borne diseases being reported. The hypothesis can be physically verified. a. the following hypothesis seems to be the most accurate – water supply has been shut off due to reports of contaminated water being supplied resulting in spread of water borne diseases. b. The hypothesis can be tested by analysing the water sample for possible pathogens and correlate it with the kind of disease being reported. 2. Principle of Repeatability: Water samples can be collected from a variety of households and tested for the presence of pathogens, their population levels and toxicity. If similar results emerge from a majority of the water samples collected and analysed for the same parameters then the hypothesis may be accepted. 3. A self-centred, consumerist, ‘what’s in it for me’ attitude person, would not want to, or, even be able to understand environmental issues and concerns. The decision to exploit or use a natural resource, not just trees, must definitely, be based on a detailed risk analysis and must also take into consideration the views of the people who are directly dependent and benefit from the resource. CHAPTER 3: 1. The basic building block of any matter is called an atom. Several atoms combine to form an element. A combination of atoms and/or elements is a molecule. 2. Temperature, pH, dissolved oxygen, turbidity & suspended sediments, specific conductivity, hardness. Testing water quality for these parameters gives a general indication of the commercial activities prevalent in the area and is a good indicator of the environmental health of the region. 3. The process of converting atmospheric nitrogen into ammonia is called nitrogen fixation. The fixed nitrogen is then used by plants to convert them into amino acids, proteins, nucleic acids etc. Animals use these to build proteins and other molecules 4. The primary producers and top consumers have not changed. The difference now though, is the unbalanced structure of the food chain and food web owing to the growing human population coupled with decreasing habitats and the pressure that this exerts on the ecosystem. CHAPTER 4: 1. Birds may have adapted and developed the ability to fly to escape from predators, to access new food sources from earlier unoccupied niches, to move quicker from point to point. 2. Ecosystems are in a constant state of change and consequently the species inhabiting the ecosystem change. Changes in the species structure of any given ecosystem over a period of time, is called ecological succession. It starts with pioneer species invading a newly created niche and continues till a stable climax species is established. For e.g. Land that has been degraded, if protected and left un-disturbed, will regenerate itself in a matter of 5-7 years starting initially with pioneer species – weeds and progressing on to thorny shrubs and small trees. 3. When one species of the two interacting species consumes the other it is called predation. When two interacting species compete for the same resource it is called competition. The stronger of the two species usually establishes itself in the ecosystem. When both the interacting species benefit from an interaction it is called mutualism. CHAPTER 5: 1. Coral reefs are generally found between the equator and the tropics where the ocean temperatures range from18-290C. Run-off from agricultural land, pollution, over-fishing, coastal area development projects have all affected coral reefs. 2. In the hot and dry deserts the maximum day temperatures range from 43.5 - 490 C, while night temperatures reach -180C. The precipitation patterns could be as low as 1.5cm a year. In the semi arid deserts, the maximum day temperatures do not go beyond 380C, while night time temperatures could dip to 100 C. The mean annual rainfall is about 2-4 cm per year. The coastal deserts usually have day temperatures reaching 350C and night temperatures falling to -40C. The precipitation ranges from 8-13cm per year. In the cold deserts the winter temperatures are between -2 to 40C. It receives snow as well as an annual mean rainfall of 26cm per year. The average rainfall in a tropical rainforest biome is usually between 125- 660cm/year and mean temperatures rarely go over 340C or drop below 200C. 3. The aquatic, forest and grassland biomes are most affected by human activity. The ever increasing population and the demands that this growing population exerts on the available resources for food, fodder, clothing etc has led to large scale clearing of forests and grasslands for agriculture and animal husbandry. The unsustainable management of these areas has resulted in general degradation and destruction of these ecosystems. Aquatic ecosystems are also being over exploited and wetlands and flood plains are being converted to agricultural land. All these activities adversely affect the diversity and therefore the stability and resilience of the ecosystems. 4. The different zones of the ocean starting form top to ocean bed are – epipelagic, mesopelagic, bathypelagic, abyssopelagic and hadal. The different zones of the lake starting from top to lake bed are – epilimnion, hypolimnion, mesolimnion and benthos. This classification is based on the amount of sunlight entering the water and the gradations in temperature. The top two layers in both cases are warm and mixed by wind and wave action. This is the most productive region and much of the biological activity occurs here. The region below the thermocline in both situations sees very little life and is cold and dark. The depth of each zone and the temperature and light gradient varies considerably in the two systems. 5. The interface between terrestrial ecosystems and aquatic ecosystems constitute the wetlands. The wetlands are highly productive and provide habitats for a wide range of plant and animal species CHAPTER 6: 1. If left unrestricted populations would grow exponentially 2. The following factors limit population growth – the available physical and biological natural resources, birth and death rates, number of individuals in the reproductive age, natural and man-made disasters, technological advances. 3. r-selected species are small sized, reproduce fast, have higher dispersal rates, are less evolved e.g. – bacteria, small insects etc. K-selected species are bigger, have long gestation periods, reproduce slowly, invest a lot in the offspring and are highly evolved; e.g. - humans, elephants etc. 4. Survivorship is the ability of an organism to survive in a given environment over a given period of time. 5. Island biogeography gives an indication of the evolutionary mechanisms at work when populations are protected and isolated spatially, temporally and reproductively. UNIT 2 – ASSIGNMENT CHAPTER 7: 1. According to Malthus, human populations, if left unrestricted, would continue to grow exponentially till the availability of food supply becomes a limiting factor. 2. Death rate is an indication of the number of deaths per 1000 of a population per year. With an increase or decrease in death rates, there is a corresponding change in population growth depending on other variables like birth rate, resource availability etc. 3. Demographic transition is the change from high birth and death rates to low birth and death rates in any given population over a certain period of time. CHAPTER 8: 1. The WHO definition of ‘health’ is “A state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.” In medical terms ‘disease’ is “any deviation from or interruption of the normal structure or function of any body part, organ, or system that is manifested by a characteristic set of symptoms and signs and whose aetiology, pathology, and prognosis may be known or unknown.” 2. Poor environmental quality including factors like soil, air, water, food, occupational hazards are some of the major sources of environmental health risk. 3. Continuous use of DDT to control mosquitoes has resulted in them developing resistance to the chemical. The theory of natural selection sets in and species tolerant/resistant to the chemical thrive. A protein that metabolizes DDT has been identified in the Anopheles gambiae species of mosquito which gives it resistance to this chemical. CHAPTER 9: 1. Famine is large scale hunger; there is severe shortage of nutrition providing food resulting in mass starvation and death. A combination of these factors – poverty, conflict from political instability, environmental factors like drought, natural calamities, poor agricultural practices all contribute to famine. 2. Soil quality is dependent on a number of factors including soil erosion by wind/ water, prevalent agricultural practices and land use patterns. CHAPTER 10: 1. algicide-algae; avicide-birds; bactericide -bacteria; fungicide-fungi herbicide- weeds; insecticide-insects; miticide- mites; molluscicide-snails, slugs; nematicide-nematodes piscicide-fish; rodenticide-rodents. 2. The slow rate of degradation, tendency for bio-accumulation, long range transport of the chemicals, high toxicity, all pose serious threats to the both environmental and human health. 3. Rodenticides and insecticides are commonly found in most households to kill rats and other obnoxious insects like cockroaches, ants etc. Net-proofing the windows, doors, drains etc with wire mesh would be a long-term, more economical and ecologically sound method of rat/insect proofing the house. CHAPTER 11: 1. Lack of biodiversity leads to risk of entire populations being wiped out during a disease or pest outbreak. All nutritional needs may not be met from the few species being used. It also causes imbalance in the ecosystem as natural habitats are altered and inter and intra species interactions are disturbed. 2. Population explosion, habitat destruction, over exploitation of natural resources and pollution are the major causes for loss in biodiversity. 3. Strategies for conservation: protect nature, understand the inter-connectedness in nature, recycle and reuse resources, use renewable sources of energy, equitable sharing of resources, accountability, assuming responsibility. CHAPTER 12: 1. Wood has been used as a construction material for houses, furniture, ships, toys, bridges, fences. It has been used in the paper and pulp industry, and in the production of charcoal, cork, and other insulation materials. More recently it is used in producing artificial silk, carpets, ropes and other fabrics. 2. This system of agriculture is practiced by local tribal communities. Forest areas are cleared and burnt down for growing agriculture crops. The cleared and burnt area is rich in nutrients and, theoretically, therefore yields of agriculture crops are high. The cleared area is cultivated for about 2 years after which it is left to regenerate for a period of 15-20 years. By this time, the land regenerates and establishes a secondary forest. The process of clearing happens again and the cycle continues. This is a sustainable method provided the land is allowed to regenerate. However, with increasing population and pressure for agriculture land increasing, the withholding period for natural regeneration is not respected and therefore this method of cultivation has become unsustainable. 3. Indigenous communities have been the custodians of their territories, natural resources and land for several generations and have used the resources available to them in a sustainable and efficient manner. However, they are being displaced at an alarming rate – their lands are being seized, cultures being ridiculed and foreign life styles are being imposed on them; all this in the name of “development.” Recognizing their rights and establishing legal frameworks that support (for e.g. land reforms) and re-establish their rights over these areas would be a socially responsible and just action to take. Handing over responsibility of managing their natural resources, land and environment would also achieve the dual purpose of environmental protection as well as protecting the rights of indigenous communities and conservation of their cultures, practices and traditional wisdom. CHAPTER 13: 1. Any region that is rich in biodiversity or is a habitat for threatened species is declared by the government as a National Park with the primary intention of protecting it from human encroachment, development and pollution. National parks are however open to public who can visit these parks for a fixed time after paying a fee. The fee collected is used for the sustainable management and conservation activities of the park. Preserves are areas within or surrounding the National parks that are generally set aside for conservation and research activities. These are generally managed by the government and serve as “live laboratories” for testing and demonstrating sustainable techniques and methods of land, water and biodiversity management. 2. The impact of skewed management practices and development policies have adversely affected the ecosystem as a whole. Landscape ecology is a relatively recent branch of ecology that views ecosystems as dynamic open systems where there is constant state of movement of energy and materials across, to and from the boundaries of the ecosystem. It considers the spatial and temporal distribution of the elements (including humans) constituting the system and the ways in which these elements interact with one another, change and cause change in the system over a period of time. An understanding of these parameters enables us to manage our ecosystems in a manner that is ecologically stable, economically viable and socially just. Ecosystem management developed as a concept to help people understand that ecosystems have several components and that a proper understanding of the inter-linkages between the various components of an ecosystem would help in the sustainable management of these systems. The underlying theme of this system of management is, to ensure that ecosystems provide a range of products and services for current and future generates without adversely affecting the quality and stability of the system. 3. Wetlands and flood plains help channel water to downstream areas during flood events, during storms the coastal wetlands reduce the impact of large waves and winds thereby mitigating their damage potential, they help to stabilize shorelines and reduce erosion, act as filters and help reduce pollution of downstream areas, they support a high diversity of life forms – both plants and animals. In fact, they serve as breeding grounds for a wide variety of fish, insect, bird, reptiles, amphibian and mammalian species. Besides all these, they also provide aesthetic and recreational services, indicating a tourism potential. 4. Reintroduction of a top consumer into an ecosystem requires careful evaluation and planning. Generally the decline of any population in any ecosystem is either a direct or indirect consequence of human interaction, interference and exploitation. Reducing the population level of a top consumer in an ecosystem has effects on the populations of all species – animals and plants inhabiting the lower trophic levels. Introducing the Gray wolf - a top level consumer - into an ecosystem would initially increase their numbers dramatically as there would be very few limiting factors to their population growth. They would become ‘keystone species’ and play a crucial role in regulating species populations and diversity of species within the system. They could also play a significant role as an equalizing force to maintain stability within the ecosystem. The social and legal issues relating to introduction of a predator species and the consequences it has for tourism and people inhabiting the surrounding areas for e.g. attacks on humans and cattle, must also be carefully studied and evaluated. REFERENCES: http://www.epa.gov/ow/ Read More