chapter 52 an introduction to ecology and the biosphere
Overview
The first chapter in the ecology unit gives a short briefing on the numerous levels of ecology and then goes into terrestrial biomes in section 52.2. The fact that disturbances and climate control the structure and distribution of biomes, or major life zones, is emphasized. A disturbance is an event such as a fire, storm, or detrimental human activity that changes a community. Climate allows for the latitudinal pattern of terrestrial biomes across the globe. A climograph plots the annual mean temperature and precipitation in particular regions (pictured below).
In terrestrial biomes, areas of intergradation, called ecotones, may occur between separate biomes; there are not permanent or distinct lines between them. The tropical forest, desert, savanna, chaparral, temperate grassland, northern coniferous forest, temperate broadleaf forest, and tundra all exhibit unique compositions of plants and animals and make up the terrestrial biomes of Earth.
The first chapter in the ecology unit gives a short briefing on the numerous levels of ecology and then goes into terrestrial biomes in section 52.2. The fact that disturbances and climate control the structure and distribution of biomes, or major life zones, is emphasized. A disturbance is an event such as a fire, storm, or detrimental human activity that changes a community. Climate allows for the latitudinal pattern of terrestrial biomes across the globe. A climograph plots the annual mean temperature and precipitation in particular regions (pictured below).
In terrestrial biomes, areas of intergradation, called ecotones, may occur between separate biomes; there are not permanent or distinct lines between them. The tropical forest, desert, savanna, chaparral, temperate grassland, northern coniferous forest, temperate broadleaf forest, and tundra all exhibit unique compositions of plants and animals and make up the terrestrial biomes of Earth.
Big Ideas
2.D.1 All biological systems from cells to and organisms to populations, communities, and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy.
Artifact
My notes on the chapter can be found below:
2.D.1 All biological systems from cells to and organisms to populations, communities, and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy.
Artifact
My notes on the chapter can be found below:
ch52_notes.pdf | |
File Size: | 821 kb |
File Type: |
Reflection
These are another example of my notes on the chapter. The required reading for Chapter 52 was quite short, so I only took notes on the overview of ecology and the terrestrial biomes. I remember that I actually read too much of the chapter and also studied aquatic biomes, though that was not necessary. Still, I was very interested in the ecology unit and expected to learn how our Earth's ecosystems work together. The first ecology chapter (section 52.2) only gave a brief overview of the terrestrial biomes and some info on climates and disturbance. I was ready to read what followed.
These are another example of my notes on the chapter. The required reading for Chapter 52 was quite short, so I only took notes on the overview of ecology and the terrestrial biomes. I remember that I actually read too much of the chapter and also studied aquatic biomes, though that was not necessary. Still, I was very interested in the ecology unit and expected to learn how our Earth's ecosystems work together. The first ecology chapter (section 52.2) only gave a brief overview of the terrestrial biomes and some info on climates and disturbance. I was ready to read what followed.
chapter 53 population ecology
Overview
Population ecology focuses on groups of individuals of the same species that live in the same area, hence the word "population." The density, dispersion, and demographics of any one population influence the biological processes that occur within that population. Ecologists can estimate the densities and sizes of populations by using techniques like the mark-recapture method (see Artifact section below). The different ways in which members of a population can be dispersed also give important information for studying them (see examples below). Vital life statistics, such as life tables, survivorship curves, and reproductive rates, certainly provide necessary information about the population as well.
Furthermore, the rates of increase or decrease of members allow biologists to describe population growth. The exponential model exemplifies population increase in ideal conditions, while the logistic model incorporates carrying capacity, meaning that the growth rate slows down.
Also, organisms can be divided into K-strategists and r-strategists. K-strategists are density-dependent (death/birth rates change with population density), while r-strategists are density-independent. Competition, predation, wastes, territoriality, and disease regulate the size of populations. Currently, the human population is increasing rapidly, but not exponentially. The size of the human population is limited by every person's ecological footprint, the land and water required to sustain that person's life. The less land every person uses, the better of the world would be. (2.5 acres of land producing potatoes: feeds 22 people, 2.5 acres of land producing beef: feeds 1 person)
Population ecology focuses on groups of individuals of the same species that live in the same area, hence the word "population." The density, dispersion, and demographics of any one population influence the biological processes that occur within that population. Ecologists can estimate the densities and sizes of populations by using techniques like the mark-recapture method (see Artifact section below). The different ways in which members of a population can be dispersed also give important information for studying them (see examples below). Vital life statistics, such as life tables, survivorship curves, and reproductive rates, certainly provide necessary information about the population as well.
Furthermore, the rates of increase or decrease of members allow biologists to describe population growth. The exponential model exemplifies population increase in ideal conditions, while the logistic model incorporates carrying capacity, meaning that the growth rate slows down.
Also, organisms can be divided into K-strategists and r-strategists. K-strategists are density-dependent (death/birth rates change with population density), while r-strategists are density-independent. Competition, predation, wastes, territoriality, and disease regulate the size of populations. Currently, the human population is increasing rapidly, but not exponentially. The size of the human population is limited by every person's ecological footprint, the land and water required to sustain that person's life. The less land every person uses, the better of the world would be. (2.5 acres of land producing potatoes: feeds 22 people, 2.5 acres of land producing beef: feeds 1 person)
Big Ideas
2.A.1 All living systems require constant input of free energy.
2.D.1 All biological systems from cells to and organisms to populations, communities, and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy.
4.A.5 Communities are composed of populations or organisms that interact in complex ways.
Artifact
Please CLICK HERE to see an overview of the mark and recapture lab.
Reflection
This chapter was harder for me to get through, especially because some of the formulas were difficult to understand by just reading the textbook. That is one reason why I found the mark-recapture lab to be so helpful in learning about population ecology. In this lab, we modeled a population and used the method to estimate our population's size. This gave us some insight into how ecologists may examine populations in the wild to figure out an approximate population size. We did experience quite a sizeable margin of error, however with estimations this may not be a big problem. I liked performing this experiment because we got to learn how a method described on paper in the textbook could be applied to the actual world.
2.A.1 All living systems require constant input of free energy.
2.D.1 All biological systems from cells to and organisms to populations, communities, and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy.
4.A.5 Communities are composed of populations or organisms that interact in complex ways.
Artifact
Please CLICK HERE to see an overview of the mark and recapture lab.
Reflection
This chapter was harder for me to get through, especially because some of the formulas were difficult to understand by just reading the textbook. That is one reason why I found the mark-recapture lab to be so helpful in learning about population ecology. In this lab, we modeled a population and used the method to estimate our population's size. This gave us some insight into how ecologists may examine populations in the wild to figure out an approximate population size. We did experience quite a sizeable margin of error, however with estimations this may not be a big problem. I liked performing this experiment because we got to learn how a method described on paper in the textbook could be applied to the actual world.
chapter 54 community ecology
Overview
A community is an interacting group of species living in the same area. These interactions can be classified by postitive, neutral, or negative effects. Competition (--/--) occurs when individuals compete for resources. Sometimes, the inferior competitor may be eliminated in competitive exclusion, or resource partitioning allows for differentiation of the ecological niches and survival of both species. Predation (+/--) is beneficial to the predator, but obviously bad for the prey. Similarly, herbivory (+/--) is beneficial to the consumer and detrimental to the plant being consumed. Symbiosis, in which individuals live in direct and intimate contact can be harmful, helpful, or neutral (see image below text). Facilitation means that one species can have helpful or neutral effects on another species without real symbiosis.
Biological communities are defined by the diversity and trophic structure within. A variety of different organisms make up a community and account for species diversity. The feeding relationships between these organisms can be organized into food chains and food webs, showing how energy is transferred through trophic levels and the feeding relationships. In a community there can be dominant species, which are very abundant and have the highest biomass, ecosystem engineers, who drastically alter their environment, and keystone species which exert a lot of control by performing important ecological roles.
Disturbances change communities by removing organisms or altering resource availability. Intermediate disturbance can foster greater diversity than low or high levels of disturbance. After a disturbance, a transition in species composition follows. Primary succession occurs in an area where there were no organisms and no soil before and secondary succession occurs when an existing community was cleared, but soil stayed behind. Biogeographic factors can also influence community diversity. Evapotranspiration correlates with species richness and the island equilibrium model shows how immigration/emigration and births/deaths contribute to species composition and population size. Pathogens can of course also change community structure on a small and large scale.
A community is an interacting group of species living in the same area. These interactions can be classified by postitive, neutral, or negative effects. Competition (--/--) occurs when individuals compete for resources. Sometimes, the inferior competitor may be eliminated in competitive exclusion, or resource partitioning allows for differentiation of the ecological niches and survival of both species. Predation (+/--) is beneficial to the predator, but obviously bad for the prey. Similarly, herbivory (+/--) is beneficial to the consumer and detrimental to the plant being consumed. Symbiosis, in which individuals live in direct and intimate contact can be harmful, helpful, or neutral (see image below text). Facilitation means that one species can have helpful or neutral effects on another species without real symbiosis.
Biological communities are defined by the diversity and trophic structure within. A variety of different organisms make up a community and account for species diversity. The feeding relationships between these organisms can be organized into food chains and food webs, showing how energy is transferred through trophic levels and the feeding relationships. In a community there can be dominant species, which are very abundant and have the highest biomass, ecosystem engineers, who drastically alter their environment, and keystone species which exert a lot of control by performing important ecological roles.
Disturbances change communities by removing organisms or altering resource availability. Intermediate disturbance can foster greater diversity than low or high levels of disturbance. After a disturbance, a transition in species composition follows. Primary succession occurs in an area where there were no organisms and no soil before and secondary succession occurs when an existing community was cleared, but soil stayed behind. Biogeographic factors can also influence community diversity. Evapotranspiration correlates with species richness and the island equilibrium model shows how immigration/emigration and births/deaths contribute to species composition and population size. Pathogens can of course also change community structure on a small and large scale.
Big Ideas
2.D.1 All biological systems from cells to and organisms to populations, communities, and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy.
2.E.3 Timing and coordination of behavior are regulated by various mechanisms and are important in natural selection.
4.A.5 Communities are composed of populations or organisms that interact in complex ways.
4.A.6 Interactions among living systems and with their environment result in the movement of matter and energy.
4.B.3 Interactions between and within populations influence patterns of species distribution and abundance.
4.C.4 The diversity of species within an ecosystem may influence the stability of the ecosystem.
Artifact
Click on the file below to see my notes on Chapter 54:
2.D.1 All biological systems from cells to and organisms to populations, communities, and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy.
2.E.3 Timing and coordination of behavior are regulated by various mechanisms and are important in natural selection.
4.A.5 Communities are composed of populations or organisms that interact in complex ways.
4.A.6 Interactions among living systems and with their environment result in the movement of matter and energy.
4.B.3 Interactions between and within populations influence patterns of species distribution and abundance.
4.C.4 The diversity of species within an ecosystem may influence the stability of the ecosystem.
Artifact
Click on the file below to see my notes on Chapter 54:
ch54_notes.pdf | |
File Size: | 1975 kb |
File Type: |
Reflection
Another example of my notes can be found above. Taking notes really helps me to remember the information that I learn from reading the textbook. Writing everything down in an organized way also provides a resource to use for looking back and reviewing the concepts. My notes were extremely important for my learning throughout the year and may even help me in the future, should I choose to study a related subject. Processing all of the terms in this chapter by taking notes and studying the images made it easy to understand community ecology. The images in this chapter were particularly helpful to connect with vocabulary.
Another example of my notes can be found above. Taking notes really helps me to remember the information that I learn from reading the textbook. Writing everything down in an organized way also provides a resource to use for looking back and reviewing the concepts. My notes were extremely important for my learning throughout the year and may even help me in the future, should I choose to study a related subject. Processing all of the terms in this chapter by taking notes and studying the images made it easy to understand community ecology. The images in this chapter were particularly helpful to connect with vocabulary.
chapter 55 ecosystems and restoration ecology
Overview
This chapter revolves around the way ecosystems function and which factors influence them. The physical laws of of conservation of mass and energy obviously apply to ecosystems and govern energy flow. Ecosystems are open systems that absorb energy & mass, but release heat & waste. Also, trophic levels make up the method of production and consumption. The energy transfer between levels is generally only 10% efficient. This chapter does mention how crucial the human diet is to the carrying capacity and well-being of Earth, since plant-based diets are so much more efficient, energy-, land-, and health-wise.
Primary production is the amount of light energy converted to chemical energy. Gross primary production (GPP) represents the total primary production in an ecosystem, while net primary production (NPP) represents the energy available to consumers. Of course primary production is restricted by the available light, limiting nutrients, and climate.
The biological and geochemical mechanisms, such as the water, carbon (see image below), nitrogen, and phosphorus cycles, process and re-incorporate essential nutrients and water into ecosystems. Decomposers rely on temperature, moisture, and nutrients to process elements of the cycles. Many of the most important elements cycle globally.
For damaged ecosystems, restoration ecologists can use techniques such as bioremediation to depollute ecosystems and biological augmentation to reintroduce deplenished nutrients to a degraded ecosystem.
This chapter revolves around the way ecosystems function and which factors influence them. The physical laws of of conservation of mass and energy obviously apply to ecosystems and govern energy flow. Ecosystems are open systems that absorb energy & mass, but release heat & waste. Also, trophic levels make up the method of production and consumption. The energy transfer between levels is generally only 10% efficient. This chapter does mention how crucial the human diet is to the carrying capacity and well-being of Earth, since plant-based diets are so much more efficient, energy-, land-, and health-wise.
Primary production is the amount of light energy converted to chemical energy. Gross primary production (GPP) represents the total primary production in an ecosystem, while net primary production (NPP) represents the energy available to consumers. Of course primary production is restricted by the available light, limiting nutrients, and climate.
The biological and geochemical mechanisms, such as the water, carbon (see image below), nitrogen, and phosphorus cycles, process and re-incorporate essential nutrients and water into ecosystems. Decomposers rely on temperature, moisture, and nutrients to process elements of the cycles. Many of the most important elements cycle globally.
For damaged ecosystems, restoration ecologists can use techniques such as bioremediation to depollute ecosystems and biological augmentation to reintroduce deplenished nutrients to a degraded ecosystem.
Big Ideas
2.A.1 All living systems require constant input of free energy.
2.D.1 All biological systems from cells to and organisms to populations, communities, and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy.
4.A.6 Interactions among living systems and with their environment result in the movement of matter and energy.
Artifact
The reading guide can be found below:
2.A.1 All living systems require constant input of free energy.
2.D.1 All biological systems from cells to and organisms to populations, communities, and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy.
4.A.6 Interactions among living systems and with their environment result in the movement of matter and energy.
Artifact
The reading guide can be found below:
ch55_readingguide.pdf | |
File Size: | 1159 kb |
File Type: |
Reflection
This seemed like the chapter I was more interested in than the previous ones. Ecosystems. Restoration. However, I learned about trophic levels and biogeochemical cycles, which was more of a review. And there was only one small section regarding the impact of humans and efforts to restore ecosystems. The reading guide (of course) was helpful to think about the information presented in the chapter. The images I had to label were especially good for learning the concepts. However, I was disappointed by some of the actual content. There was more about how energy cycles through an ecosystem, and less about how ecosystems are suffering throughout the world. More about the effects and consequences, less about the causes (which are what needs to be addressed).
This seemed like the chapter I was more interested in than the previous ones. Ecosystems. Restoration. However, I learned about trophic levels and biogeochemical cycles, which was more of a review. And there was only one small section regarding the impact of humans and efforts to restore ecosystems. The reading guide (of course) was helpful to think about the information presented in the chapter. The images I had to label were especially good for learning the concepts. However, I was disappointed by some of the actual content. There was more about how energy cycles through an ecosystem, and less about how ecosystems are suffering throughout the world. More about the effects and consequences, less about the causes (which are what needs to be addressed).
chapter 56 conservation biology and global change
Overview
Sections 56.1 and 56.4 focus on threats to Earth's biodiversity and specific examples of ways in which the world's ecosystems are changing -- for the worse. The variety of species in many, many ecosystems rapidly decreases every day. Human actions endanger the very ecosystem services through which water, air, and wastes are decontaminated. Habitat loss is the single greatest threat to biodiversity, worsening the condition of the world because of mining, urban, development, and a.n.i.m.a.l. a.g.r.i.c.u.l.t.u.r.e, the one reason 90% of original (U.S.) forest has been lost. Introduced species may also disrupt communities due to intentional or accidental movement from native locations to new regions. Over-harvesting of wild organisms for human benefit exceeds the ability of populations to rebound and only promotes collapse of communities. These actions cause alterations in climate, atmospheric chemistry, and broad ecological systems.
As a result of human exploitation and interference, practices such as nutrient enrichment that exceed the critical load support toxic environments and pollution of soil, water, oceans, even animals. An example of this pollution would be biological magnification, which happens when toxins concentrate in successive trophic levels and accumulate in the tissues of organisms. Other important changes include rising CO2 levels, overall warming of the global temperature, and depletion of atmospheric ozone.
Big Ideas
2.D.2 Homeostatic mechanisms reflect both common ancestry and divergence due to adaptation in different environments.
2.D.3 Biological systems are affected by disruptions to their dynamic homeostasis.
4.B.4 Distribution of local and global ecosystems changes over time.
4.C.4 The diversity of species within an ecosystem may influence the stability of the ecosystem.
Artifact
Please click HERE to learn more about the way our world is changing and watch one of the most intriguing documentaries to date.
*REFLECTION*
The content of these last few chapters can safely be categorized as the most important information for our generation which the Campbell Biology book covers. The way that the different systems of our world interact and evolve gravely affects the future of all species on this planet. Currently, the ecological sustainability of our environment is in obvious and critical danger. This may have been true many years ago and will be true for years to come, but the importance of acting on the failures of the human species to share this Earth with other organisms can not be stressed enough.
Although this textbook is factual and composed a couple of years ago, I feel there are not enough facts about the specific causes of habitat loss, overharvesting, rising CO2, etc. in these chapters. This chapter lacks sufficient information and scientific study to illustrate how human actions such as animal agriculture, mining, and more affect the health of our world.
Though the causes of climate change are plentiful and controversial, rock hard analysis of the observed developments around the globe repeatedly shows one thing: without the extensive human exploitation of Earth's land and animals, the damage done to the planet's stability could reverse. The entirety of our transportation system contributes up to four times less greenhouse gas emissions than animal agriculture. The Earth's oceans are being over-fished at an absolutely alarming rate; for every 1 lb of harvested fish, 5 lbs of "bykill" result. Every second, the rain forests that provide us with the air we breathe are mutilated and turned into lifeless land. The "conservation biology" described in this chapter is necessary and often helpful to stabilize ecosystems, but at this rate of destruction, that approach just won't cut it.
Collectively, the human species must work towards a sustainable future, and fast. We must work together to shape a world in which our children and children's children will be able to live peacefully and consciously. The only constant is change.
Sections 56.1 and 56.4 focus on threats to Earth's biodiversity and specific examples of ways in which the world's ecosystems are changing -- for the worse. The variety of species in many, many ecosystems rapidly decreases every day. Human actions endanger the very ecosystem services through which water, air, and wastes are decontaminated. Habitat loss is the single greatest threat to biodiversity, worsening the condition of the world because of mining, urban, development, and a.n.i.m.a.l. a.g.r.i.c.u.l.t.u.r.e, the one reason 90% of original (U.S.) forest has been lost. Introduced species may also disrupt communities due to intentional or accidental movement from native locations to new regions. Over-harvesting of wild organisms for human benefit exceeds the ability of populations to rebound and only promotes collapse of communities. These actions cause alterations in climate, atmospheric chemistry, and broad ecological systems.
As a result of human exploitation and interference, practices such as nutrient enrichment that exceed the critical load support toxic environments and pollution of soil, water, oceans, even animals. An example of this pollution would be biological magnification, which happens when toxins concentrate in successive trophic levels and accumulate in the tissues of organisms. Other important changes include rising CO2 levels, overall warming of the global temperature, and depletion of atmospheric ozone.
Big Ideas
2.D.2 Homeostatic mechanisms reflect both common ancestry and divergence due to adaptation in different environments.
2.D.3 Biological systems are affected by disruptions to their dynamic homeostasis.
4.B.4 Distribution of local and global ecosystems changes over time.
4.C.4 The diversity of species within an ecosystem may influence the stability of the ecosystem.
Artifact
Please click HERE to learn more about the way our world is changing and watch one of the most intriguing documentaries to date.
*REFLECTION*
The content of these last few chapters can safely be categorized as the most important information for our generation which the Campbell Biology book covers. The way that the different systems of our world interact and evolve gravely affects the future of all species on this planet. Currently, the ecological sustainability of our environment is in obvious and critical danger. This may have been true many years ago and will be true for years to come, but the importance of acting on the failures of the human species to share this Earth with other organisms can not be stressed enough.
Although this textbook is factual and composed a couple of years ago, I feel there are not enough facts about the specific causes of habitat loss, overharvesting, rising CO2, etc. in these chapters. This chapter lacks sufficient information and scientific study to illustrate how human actions such as animal agriculture, mining, and more affect the health of our world.
Though the causes of climate change are plentiful and controversial, rock hard analysis of the observed developments around the globe repeatedly shows one thing: without the extensive human exploitation of Earth's land and animals, the damage done to the planet's stability could reverse. The entirety of our transportation system contributes up to four times less greenhouse gas emissions than animal agriculture. The Earth's oceans are being over-fished at an absolutely alarming rate; for every 1 lb of harvested fish, 5 lbs of "bykill" result. Every second, the rain forests that provide us with the air we breathe are mutilated and turned into lifeless land. The "conservation biology" described in this chapter is necessary and often helpful to stabilize ecosystems, but at this rate of destruction, that approach just won't cut it.
Collectively, the human species must work towards a sustainable future, and fast. We must work together to shape a world in which our children and children's children will be able to live peacefully and consciously. The only constant is change.