Ch 57. Understanding Ecosystems
Ecosystem, Habitat & Niche | Definition, Differences & Examples
The terms ecosystem, habitat, and niche are related but are not the same things. Ecosystems are the dynamic interaction between the biotic and abiotic (living and nonliving, respectively) factors in a geographic area. The habitat is a place suitable for a particular organism to live, and the niche of an organism is the unique and specific role it plays in its ecosystem. Animals can occupy the same habitats and ecosystems, but will not have the exact same niches. The feeding habits and other adaptations determine the niche of an animal within its ecosystem. For example, cheetahs and lions have different hunting styles, so they are able to coexist in the same habitat. Ecosystems and habitats contain will host populations or individuals of a certain species that interact in an area. The population density, or numbers of individuals of a population within a certain sized area, will change as conditions change. Factors that are density-dependent, such as disease, predation, competition for resources etc., are typically also biotic factors within the ecosystem. There are also density-independent factors that affect the population density of an ecosystem, and these are typically abiotic factors such as weather, climate, pollution, amount of oxygen, etc.
Questions and Answers: Types of Biomes on a Map
1. What is a biome, and how is it defined in relation to plants, animals, and climate? Answer: A biome is a regional area characterized by the plants, animals, and climate specific to that area. Plants and animals in biomes are often unique and endemic to that particular region. 2. Name the five primary biomes in the world and briefly describe their defining characteristics. Answer: The five primary biomes are Grassland, Desert, Forest, Aquatic Biome, and Tundra. Each has different temperatures, climates, native animals, and vegetation that define its characteristics.
Questions and Answers: Ecological Succession
1. What is ecological succession, and how does it demonstrate nature's resilience? Answer: Ecological succession is the process in which disturbed regions are recolonized by organisms that are gradually replaced by new species. It illustrates nature's resilience by showcasing the recovery of plant communities after a dramatic disturbance. 2. What are the stages involved in ecological succession, and how do they relate to the recovery of ecosystems? Answer: The stages of ecological succession are Initial Conditions (Equilibrium), Disturbance, Colonization, Competition, Succession, and Climax. These stages represent the recovery process of ecosystems after disruption, starting with the existing conditions and ending in a stable climax community.
Questions and Answers: Ecology Overview
1. What is ecology, and how does it encompass the study of organisms on Earth? Answer: Ecology is the study of all organisms on Earth, their physical surroundings, and their interactions. It explores how living and non-living factors interact. It encompasses the examination of different branches such as population ecology, community ecology, and ecosystem ecology. 2. Differentiate between population ecology, community ecology, and ecosystem ecology. Answer: Population Ecology: Focuses on groups of organisms of the same species sharing an area and their interactions with resources. Community Ecology: Examines all organisms of various species in a specific area, including animals, plants, and microorganisms. Ecosystem Ecology: Studies interactions among living organisms (biotic factors), nonliving factors (abiotic factors), and their interplay in multiple communities.
Questions and Answers: Glaciation
1. What is glaciation, and how is it formally defined? Answer: Glaciation refers to the buildup and movement of ice on the Earth's surface, leaving formations and scars. Formally defined, glaciation is the forming, existence, or movement of glaciers over the Earth's surface. 2. Differentiate between glaciers and ice sheets in the context of glaciation. Answer: Glaciers are one type of glaciation, and ice sheets are another. Ice sheets are massive bodies of compacted snow covering continents, originating from the North and South poles. Glaciers, on the other hand, are formed in mountainous regions due to extreme snowfall, and their extent depends on both elevation and proximity to the poles.
Questions and Answers: Nitrogen Fixation
1. Why can't living organisms directly use atmospheric nitrogen gas, and how do some bacteria address this limitation? Answer: Atmospheric nitrogen gas is unusable for living organisms. Certain bacteria perform nitrogen fixation by adding hydrogen atoms to nitrogen, creating ammonia. This ammonia can then be incorporated into organic molecules like amino acids. 2. What are the different types of nitrogen-fixing bacteria, and where can they be found? Answer: Nitrogen-fixing bacteria include free-living soil bacteria, nitrogen-fixing symbiotic bacteria in plant roots, and cyanobacteria (blue-green algae) in the oceans. These bacteria fix nitrogen for their own use and release excess ammonia that benefits other organisms.
Biomes of The World | Savannas, Deserts, & Rainforests
A biome is defined as a regional area characterized by the plants, animals, and climate in that area. Many of the plants and animals located in these areas area endemic to the biome. This means they are unique to that biome and only found in that specific part of the world. There are five basic biomes, each with different temperatures, climates, and vegetation that define its characteristics. Grassland biomes are located in the middle latitudes and can be divided into savannas and temperate grasslands. Desert biomes cover about one fifth of Earth's land surface and receive little to no precipitation. There are four main types of deserts: hot and dry, semi-arid, coastal, and cold. Forest biomes cover about one-third of Earth. This tree covered biome is found in different locations and experiences various climates. The four main types of forest biomes are temperate deciduous rainforests, tropical rainforests, jungles, and taiga boreal forests. Aquatic biomes include the areas around the world dominated by water and are the largest of all biomes covering almost 75% of Earth. Aquatic biomes can be split into freshwater and marine habitats. The tundra biome is characterized as a treeless polar desert and is the coldest and harshest biome on Earth. Permafrost is permanently frozen ground located under the soil and found in tundras.
Ecological Succession | Definition, Process & Stages
Ecological succession is the gradual and continuing replacement of plant species by other plant species after an environmental disturbance. Primary succession occurs after geological events like volcanic eruptions and glacier retreats that eliminate all topsoil in the ecosystem. It is typically a prolonged process. Secondary succession occurs after fires, floods, and agricultural activities remove vegetation from an area but leave topsoil behind. Plants in ecosystems with frequent wildfires, like chaparral biomes, have adaptations that quickly restore their populations. After a disturbance to the ecosystem, small organisms start to repopulate the environment in a process known as colonization. This first wave of species, called pioneer species, are usually hardy primary producers, and they help bring plant life back to the damaged ecosystem. Changes in abiotic (nonliving) and biotic (living) environmental factors allow some plant species to outcompete others, changing the makeup of the plant communities. As biodiversity (the number and variety of species in an ecosystem) grows, so does resource competition. Eventually, a climax community forms, which means that dominant, well-established species exist in a steady state with minimal resource competition. This new equilibrium, or balance among species populations, is ecologically stable; however, this state, and the climax community itself, is not everlasting. With the next major disturbance, the process of ecological succession will begin again.
Primary & Secondary Ecological Succession | Causes & Examples
Ecological succession is when an ecosystem eventually changes in species composition and community structure over time after a disturbance has occurred. In terrestrial ecosystems, succession can occur as either primary or secondary succession. Primary ecological succession is the type of succession that occurs when an area experiences a disturbance that is so severe that none of the original species survive and the ecosystem must rebuild from bare rock. An example of this is the recovery of an ecosystem after a volcano has covered an area with lava. Pioneer species are the first to establish and develop in a bare area. Over time, the ecosystem begins to stabilize as more species inhabit the area, and eventually, the region becomes a climax ecosystem. Secondary ecological succession occurs when an area experiences a disturbance that alters the existing ecosystem but does not destroy all of the original species. An example of secondary succession would be the recovery of a forest after a forest fire, wherein grasses, followed by shrubs and a variety of tree species, would eventually grow over time. Succession in aquatic ecosystems occurs when sediment gradually fills in the water and changes the aquatic area to a semi-aquatic or terrestrial environment. Dredging is digging and removing the sediment at the bottom of an aquatic area to reduce the sediment that can eventually lead to the succession of the aquatic ecosystem into a terrestrial ecosystem. Succession is very important for the stability of the environment.
Energy Flow in an Ecosystem | Food Chain & Trophic Levels
Food chains and food webs provide a representation of how organisms within an ecosystem interact and how energy flows through that ecosystem. Food chains represent one single chain of interactions between organisms and how energy flows through that chain. Food webs, on the other hand, show the complex interconnected interactions between all food chains within an ecosystem. Producers, or organisms that create their own food, are typically at the bottom of the food chain or web, also known as the first trophic level. Organisms can be classified into higher trophic levels, depending on what they eat and how far removed they are from the producers. Primary consumers or herbivores feed on the consumers. Secondary, tertiary, and quaternary consumers, the carnivores and omnivores in the ecosystem, feed on other consumers. Using knowledge of food chains, food webs, and how organisms fall within trophic levels, we can model how energy flows through ecosystems: from producers to herbivorous primary consumers, through secondary consumers, to tertiary and finally quaternary (or higher if the food chain is long enough) consumers. While this flow of energy is linear in a single food chain, it is interconnected and complex in the food web. Generally, the flow of energy is upward from the lowest trophic level to the highest. This flow of energy through trophic levels in ecosystems is not perfect. Energy is lost due to heat and metabolism in organisms, and not all energy will be transferred to the next trophic level. In fact, 10% of the energy is transferred from one trophic level to the next.
Frequently Asked Questions
Frequently Asked Questions What is an example of a species niche? A species niche is a specific and unique role that a certain species has within its ecosystem. Niches are typically occupied by just one species of organism. What is an animal niche? An animal niche is the specialized role or job it plays in its ecosystem. It is related to how, when, where, and what it eats, as well as other behavioral habits.
Glaciation | Overview, Causes & Examples
Glaciation refers to the buildup and movement of ice on the earth's surface. An ice age occurs on the earth as ice sheets and glaciers. Periods of glaciation can be relatively mild and isolated as was the case with the Little Ice Age, or they can be very severe and extensive. At least twice, the ice ages were so extensive they covered the earth and were named Snowball Earth. The Wisconsinan glaciation period is the most recent major period whose peak was 18 thousand years ago. The Milankovitch Cycles of eccentricity, obliquity, and precession explain the variations in the earth's position and movements that determine the amount of the sun's radiation it receives. Glaciers didn't start melting when man started recording the melting. They were once massive, and they started melting 18 thousand years ago and continue today.
Global Ecology | Biogeography, Conservation & Examples
Global ecology is an important topic for having sustainable use of resources on Earth. It studies the interactions of Earth's ecosystems with the land, the atmosphere and the oceans in hopes of finding ways to mitigate human induced damage. The branches of global ecology include population ecology, community ecology, and ecosystem ecology. There are many challenges in global ecology such as deforestation, strip mining, urbanization and converting natural areas to farmland. Humans can live in harmony with ecosystems provided they think about their actions. Camping, hiking, fishing, and other recreation can occur in ways that do not damage ecosystems. As the human population grows, there needs to be proper planning of new housing areas and roads to minimize impact on wildlife. Conservation measures to make protected areas for wildlife and plants are proven ways to help mitigate human impact on natural areas.
Frequently Asked Questions
How does ecological succession occur? Ecological succession occurs when environmental changes allow new plant species to outcompete existing plant species in a recovering ecosystem. Plant communities shift and diversify over time. What is ecological succession and its types? Ecological succession is the slow replacement of plant species by other plant species in a disturbed ecosystem. Primary succession occurs when a natural disaster leaves no topsoil behind. Secondary succession occurs when fires, floods, or human activity remove vegetation but leave the topsoil. What is the climax stage of succession? The climax stage of succession is the final stage in which the ecosystem is balanced and relatively stable. Species replacement ceases. What are examples of ecological succession? An example of primary succession is the recovery of the Mount Saint Helens region after the 1980 eruption. Small plants are gradually being replaced by larger ones on ground that was covered in ash. An example of secondary succession is the recovery of chaparral ecosystems after a wildfire. Soil and protected roots remain, allowing plant populations to recover more quickly.
Frequently Asked Questions
Is a savanna like a desert? The savanna desert shares similarities with both desert and forest biomes. It composed mainly of grasses with few scattered trees and shrubs. Yearly precipitation levels are much higher than desert biomes averaging 40 to 60 inches yearly. Is there a Savannah desert? The savanna desert is also referred to as the African savanna. It is located on the African continent and is one of the most famous savannas because of its diverse wildlife.
Fossil Fuels, Greenhouse Gases, and Global Warming
The vast majority of the world's carbon has been locked away in sediments for millions of years. However, over the past 200 years, humans have started to have a measurable effect on the carbon cycle by burning fossil fuels and releasing more CO2 into the atmosphere. This carbon that has been out of circulation for millions of years is being added to the active short-term carbon cycle. As a result, the concentration of carbon dioxide in the atmosphere has been steadily increasing year after year for at least the past 54 years in a remarkably regular seasonal pattern. This is significant because carbon dioxide is a greenhouse gas, which is a gas in the atmosphere that absorbs infrared radiation from the Earth and slows the rate of heat loss. The three major greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, and methane. In addition, over the past 800,000 years there has been a remarkable correlation between atmospheric concentrations of carbon dioxide and global temperatures. So now that CO2 levels in the atmosphere have reached their highest levels in over a million years, it's not surprising that global temperatures are increasing and glacial and polar ice is receding. There is a lot of scientific evidence to support the claim that global warming isn't just occurring but is in fact accelerating. It also doesn't look like we will reverse the addition of carbon dioxide to the atmosphere anytime soon, so it's logical to expect global warming to continue. And while this may cause the polar ice caps to melt, sea levels to rise, and some species to go extinct, life will adapt to a new global climate, just like it has in the past.
Frequently Asked Questions
What are the 3 types of ecology? The three types of ecology are population ecology, community ecology, and ecosystem ecology. Population ecology studies the organisms of one species and how they interact with each other and their environment. Community ecology studies all the species in an area and the surrounding environment. Ecosystem ecology looks at all the living organisms (biotic factors) and the abiotic factors in an area and how they interact. Is global ecology part of environmental science? Environmental science studies all organisms on Earth (biotic factors), the environment in which they live (abiotic factors) plus how humans interact with the environment, their attitudes toward the environment, and how to mitigate human impact. Global ecology studies ecosystem interaction on a world wide scale, so it is definitely a part of environmental science.
