Module 2 Lesson 1 PDF

Module 2 LESSON 1 Habitat Loss, Alteration and Fragmentation Objectives: At the end of this lesson, you should be able to: illustrate before and after effect of habitat loss, alteration and...

Module 2 LESSON 1 Habitat Loss, Alteration and Fragmentation Objectives: At the end of this lesson, you should be able to: illustrate before and after effect of habitat loss, alteration and fragmentation; determine the human activities that caused these environmental damages; and formulate possible environmental protection measures that can preserve different species of flora and fauna affected by habitat loss, alteration and fragmentation. Introduction: Hello, how are you? I hope you are doing well! Welcome to Lesson 1 of Module 2. In this lesson, you are about to learn about Pressures on Ecosystem induced by various human activities. You can use your acquired learning from previous topics in going through the tasks because these lessons are just interrelated. So, are you ready? Alright, let’s begin! Activity: Copy and paste pictures online to illustrate an untouched environment (BEFORE) and the same picture of that spot that has been developed or altered by humans (AFTER). Paste those photos in their respective boxes. See Figure 2.1 as an example below. FIGURE 1.1 ENVIRONMENTAL DAMAGES BEFORE AND AFTER PHOTO 37  BEFORE AFTER Analysis: Examine the photos you have copied and pasted in the activity task and the example provided. Answer the question below. In the given example, there are changes happened in the same spot. If trees died because they were removed for the purpose of building homes for humans, who else lost their habitats in the process? What does this scenario means to other living organisms? 38  Abstraction: In this lesson, we will emphasize how human activities caused so much changes in the ecological balance, without realizing all the environmental damages. In most cases, it is our concept of the word DEVELOPMENT that pushed us to alter our surroundings for our own benefit and always at the expense of other living entities, especially the species of flora (plants) and fauna (animals). HABITAT ALTERATION is a change in land use or land cover that has an impact on local ecosystems. Plants and animals live in specific places that have the conditions of climate and food resources needed for survival. Habitats vary from forest and grassland to urban areas, streams, ponds, and oceans. Over time, a habitat is subject to alteration, especially under the influence of human activities. Habitat alteration, which may lead to habitat loss, is the greatest current threat to living species. Large areas of land and water are damaged by human activities (see Figure 2.2): Urbanization Agriculture Overfishing FIGURE 1.2 HUMAN ACTIVITIES CAUSING HABITAT LOSS These cause fragmentation of habitats, which threatens those animals that need a large habitat for breeding and survival. Many species have already become extinct, particularly in tropical areas. This loss of biodiversity impacts food resources, 39 such as fish stocks. Loss of trees can increase soil erosion and accelerate climate change. Sustainable use of land and water is therefore needed to minimize the impact of habitat alteration. FRAGMENTATION OF HABITATS Habitat fragmentation is defined as the process during which a large expanse of habitat is transformed into a number of smaller patches of smaller total area isolated from each other by a matrix of habitats unlike the original (Fahrig, 2003). It threatens those animals that need a large habitat for breeding and survival. FIGURE 1.3 FRAGMENTATION OF HABITATS AND EFFECTS TO FAUNA SPECIES Habitat fragmentation is a major problem across the Earth. A decrease in the overall area of habitat is serious enough, but when combined with fragmentation, it can undermine the integrity of whole ecosystems. Roads, urbanization and agriculture are among the main human activities which break up natural areas, often with disastrous implications for wildlife. 40  ENVIRONMENTAL CASE Imagine that you are a rare lichen, or a bird which prefers the dark interior of the woods, such as a tree creeper. Half of your woodland home is destroyed to make way for a car park, and the remainder is bisected by a road. What happens to your cool, dark patch of the forest? It becomes flooded with light, the humidity and temperature are altered, and it may no longer suit your specific needs. Thus, fragmentation increases what is known as the ‘edge effect’, whereby the interior area of habitat is affected by the different conditions of the other habitats on its edges (see Figure 2.3). The smaller a particular habitat is, the greater is the proportion of its area which experiences the edge effect, and this can lead to dramatic changes in plant and animal communities. Habitat fragmentation leads to edge effects as shown in Figure 2.4. Microclimatic changes in light, temperature, and wind can alter the ecology around the fragment, and in the interior and exterior portions of the fragment. Fires become more likely in the area as humidity drops and temperature and wind levels rise. Exotic and pest species may establish themselves easily in such disturbed environments, and the proximity of domestic animals often upsets the natural ecology. Also, habitat along the edge of a fragment has a different climate and favors different species from the interior habitat. Small fragments are therefore unfavorable for species that require interior habitat Figure 1.4 EDGE EFFECTS FOR EDGE AND INTERIOR SPECIES 41 Application: How can humans promote economic development (continue building roads, houses, etc.) while protecting the environment? Suggest at least 3 possible environmental protection measures. Assessment: Choose the letter of your answer. Write your answer on the space provided before the item number. 1. What do you mean by ‘edge effect’? a. process by which a natural habitat becomes incapable of supporting its native species. b. change in the particular environment or place where organisms or species tend to live. c. changes in population or community structures that occur at the boundary of two or more habitats. d. the emergence of discontinuities in an organism's preferred environment, causing population fragmentation and ecosystem decay. 2. Which is NOT a contributing factor of Habitat Loss? a. Natural ecology b. Overfishing c. Urban Development 42  d. Agriculture 3. Which of the following defines what ‘habitat’ is? a. It is the wide range of plants and animals that exist within any givengeographical region. b. It is the branch of biology concerned with the relations betweenorganisms and their environment. c. Capable of being sustained or continued for an indefinite period withoutexhausting necessary resources or otherwise self-destructing d. It is the place where an organism or a community of organisms lives, including all living and nonliving factors or conditions of the surrounding environment. 4. What living organisms are negatively affected by habitat loss, alterationand fragmentation? a. Human population b. Flora and Fauna c. Natural Balance d. Edge species only 5. Habitat loss or habitat destruction happens when. a. the natural habitat becomes incapable of supporting its native species. b. there is change in the particular environment or place where organisms orspecies tend to live. c. there are changes in population or community structures that occur at theboundary of two or more habitats. d. there is emergence of discontinuities in an organism's preferred environment, causing population fragmentation and ecosystem decay. Excellent! You just finished Lesson 1 of Module 2! Should you have any questionsor queries regarding this lesson, please do not hesitate to reach out to your instructors. Are you ready to take your next lesson? Lesson 2 will discuss about Overexploitation. Good luck and enjoy reading. 43