What is Your Ecology IQ? CHAPTER 5 HOW ECOSYSTEMS WORK

Ecology the scientific study of interactions among organisms and their environment the scientific study of interactions among organisms and their environment such as the interactions organisms (biotic) have with each other and with their abiotic environment. such as the interactions organisms (biotic) have with each other and with their abiotic environment.

Environment? The external conditions or surroundings in which plants or animals live Air, water, minerals, other organisms, and all other external factors surrounding and affecting a given organism at any time. Which influence development and behavior of an organism

Ecosystem a community of living organisms a community of living organisms (plants, animals and microbes) (plants, animals and microbes) in conjunction with the nonliving components of their environment in conjunction with the nonliving components of their environment (things like air, water and mineral soil) (things like air, water and mineral soil) interacting as a system (ie. habitat) interacting as a system (ie. habitat)

Biological Community vs Population? Community Community an interacting group of various species in a common location. For example, a forest of trees and undergrowth plants, inhabited by animals and rooted in soil containing bacteria and fungi Population a group of organisms belonging to the same species that are living in the same area

What is succession? the observed process of change in the species structure of an ecological community over time the observed process of change in the species structure of an ecological community over time

Succession after disturbance: a boreal forest one (left) and two years (right) after a wildfire

What is succession? community begins with relatively few pioneering plants and animals and develops through increasing complexity until it becomes stable or self-perpetuating as a climax community community begins with relatively few pioneering plants and animals and develops through increasing complexity until it becomes stable or self-perpetuating as a climax community The ʺ engine ʺ of succession, the cause of ecosystem change – The ʺ engine ʺ of succession, the cause of ecosystem change – is the impact of established species upon their own environments is the impact of established species upon their own environments

Predictable changes following a disturbance or initial colonization of new habitat lava flow or a severe landslide, or by some form of disturbance, such as from a fire, severe windthrow, logging, of an existing community lava flow or a severe landslide, or by some form of disturbance, such as from a fire, severe windthrow, logging, of an existing community

Introduction of Invasive Species Kudzu

Types of Succession Primary succession Primary succession Begins in new habitats, uninfluenced by pre-existing communities Begins in new habitats, uninfluenced by pre-existing communities Secondary succession Secondary succession follows a disruption of a pre-existing community follows a disruption of a pre-existing community

An example of Secondary Succession by stages: 1. A stable deciduous forest community 2. A disturbance, such as a wild fire, destroys the forest 3. The fire burns the forest to the ground 4. The fire leaves behind empty, but not destroyed, soil 5. Grasses and other herbaceous plants grow back first 6. Small bushes and trees begin to colonize the area 7. Fast growing evergreen trees develop to their fullest, while shade-tolerant trees develop in the understory 8. The short-lived and shade intolerant evergreen trees die as the larger deciduous trees overtop them. The ecosystem is now back to a similar state to where it began

Secondary succession: trees are colonizing uncultivated fields and meadows

The study of succession remains at the core of ecological science

Where would an ecologist be least likely to go to study primary succession? A. A locked, abandoned asphalt parking lot in New York City A. A locked, abandoned asphalt parking lot in New York City B. The Amazon Rain Forest B. The Amazon Rain Forest C. A new island formed by a volcanic eruption C. A new island formed by a volcanic eruption D. A gravel-filled valley that had been covered by a glacier until recently D. A gravel-filled valley that had been covered by a glacier until recently

B. The Amazon Rain Forest

If an insect eats a plant and a bird eats the insect, about how much energy from the plant is stored in the insect for the bird to use? A. 90% A. 90% B. 50% B. 50% C. 10% C. 10% D. 1% D. 1%

C. 10%

Plants play a crucial role in the carbon cycle because they A. Allow carbon to enter an ecosystem through photosynthesis A. Allow carbon to enter an ecosystem through photosynthesis B. Have special bacteria that live in their root systems B. Have special bacteria that live in their root systems C. Do not release carbon dioxide during cellular respiration C. Do not release carbon dioxide during cellular respiration D. Are chemically converted into fossil fuels when burned. D. Are chemically converted into fossil fuels when burned.

A. Allow carbon to enter an ecosystem through photosynthesis

Which of the following is one of the largest carbon reservoirs on Earth? A. Oceans A. Oceans B. Limestone B. Limestone C. Amazon rain forest C. Amazon rain forest D. Fossil fuels D. Fossil fuels

A. Oceans

What term is used to refer to the many feeding relationships that are possible in an ecosystem? A. Energy transfer A. Energy transfer B. Energy pyramid B. Energy pyramid C. Food chain C. Food chain D. Food web D. Food web

D. Food web

Which of the following statements is NOT correct A. Rare bacteria that live deep in the ocean get their energy from hydrogen sulfide in hot water A. Rare bacteria that live deep in the ocean get their energy from hydrogen sulfide in hot water B. Plants and other producers get their energy directly from the sun B. Plants and other producers get their energy directly from the sun C. Animals get their energy from the sun indirectly C. Animals get their energy from the sun indirectly D. Consumers get their energy directly from the sun. D. Consumers get their energy directly from the sun.

D. Consumers get their energy directly from the sun.

Which of the following is NOT a true statement about cellular respiration? A. It is essentially photosynthesis in reverse A. It is essentially photosynthesis in reverse B. Sugar molecules are its primary products B. Sugar molecules are its primary products C. Oxygen is one of the primary reactants C. Oxygen is one of the primary reactants D. It produces energy for organisms to use D. It produces energy for organisms to use

B. Sugar molecules are its primary products

Consumers are organisms that A. Occupy an ecosystem’s lowest energy level A. Occupy an ecosystem’s lowest energy level B. Get solar or other energy indirectly B. Get solar or other energy indirectly C. Are also known as self-feeders C. Are also known as self-feeders D. Eat only other animal species D. Eat only other animal species

B. Get solar or other energy indirectly

Succession is possible because A. Climate change over time A. Climate change over time B. It is a rapid and chaotic process that is very difficult to control B. It is a rapid and chaotic process that is very difficult to control C. Existing plants reproduce quickly C. Existing plants reproduce quickly D. New species make the environment less suitable for previous ones D. New species make the environment less suitable for previous ones

D. New species make the environment less suitable for previous ones

Which of the following is NOT a likely component of soil formed during primary succession? A. Broken bits of stone and rock A. Broken bits of stone and rock B. Decayed lichens and bacteria B. Decayed lichens and bacteria C. Cast-off parts of shrubs and trees C. Cast-off parts of shrubs and trees D. Dust particles from the air D. Dust particles from the air

C. Cast-off parts of shrubs and trees

Which item is a carbon sink and NOT part of the carbon cycle? A. Consumers breaking down carbohydrates into carbon dioxide during respiration A. Consumers breaking down carbohydrates into carbon dioxide during respiration B. Carbon dioxide being converted into carbohydrates during photosynthesis B. Carbon dioxide being converted into carbohydrates during photosynthesis C. Carbon in the atmosphere in the form of carbon dioxide C. Carbon in the atmosphere in the form of carbon dioxide D. Carbon found within limestone rocks D. Carbon found within limestone rocks

D. Carbon found within limestone rocks

Which gas makes up 78% of our atmosphere but can be used by plants only when transformed by bacteria first? A. Nitrogen A. Nitrogen B. Oxygen B. Oxygen C. Carbon dioxide C. Carbon dioxide D. Hydrogen D. Hydrogen

A. Nitrogen

Which statement describes how humans are affecting the balance of carbon in the atmosphere? A. Fewer agricultural crops are planted, reducing the amount of CO 2 released into the atmosphere A. Fewer agricultural crops are planted, reducing the amount of CO 2 released into the atmosphere B. Burning fossil fuels in great quantities has increased the amount of CO 2 in the atmosphere B. Burning fossil fuels in great quantities has increased the amount of CO 2 in the atmosphere C. Overgrazing of grasslands has reduced the amount of CO 2 in the atmosphere C. Overgrazing of grasslands has reduced the amount of CO 2 in the atmosphere D. Severe drought in large areas of the world has decreased the amount of CO 2 that is released into the atmosphere D. Severe drought in large areas of the world has decreased the amount of CO 2 that is released into the atmosphere

B. Burning fossil fuels in great quantities has increased the amount of CO 2 in the atmosphere

What type of succession occurs after a natural process such as a volcanic eruption or flood? A. Old-field succession A. Old-field succession B. Climax community B. Climax community C. Primary succession C. Primary succession D. Secondary succession D. Secondary succession

D. Secondary succession

The bacteria that live within the roots of a soybean plant are a critical part of the nitrogen cycle because they A. Provide the plant with sugars needed for growth A. Provide the plant with sugars needed for growth B. Transform nitrates into nitrogen gas for release B. Transform nitrates into nitrogen gas for release C. Change atmospheric nitrogen into a usable form C. Change atmospheric nitrogen into a usable form D. Release nitrogen by decomposing dead plant parts D. Release nitrogen by decomposing dead plant parts

C. Change atmospheric nitrogen into a usable form

Which of the following is an example of secondary succession? A. Pioneer plants begin to grow after glacial melting A. Pioneer plants begin to grow after glacial melting B. Appearance of weeds in cracks in a concrete surface B. Appearance of weeds in cracks in a concrete surface C. Breaking down of bare rock by fungi and mosses C. Breaking down of bare rock by fungi and mosses D. Growth of plants after a forest is destroyed by fire. D. Growth of plants after a forest is destroyed by fire.

D. Growth of plants after a forest is destroyed by fire.

Which kind of organism obtains energy only from producers? A. Omnivores A. Omnivores B. Decomposers B. Decomposers C. Herbivores C. Herbivores D. All of the above D. All of the above

C. Herbivores

What kind of natural disaster helps some forest communities by allowing some trees to release their seeds, by clearing away deadwood, and by encouraging new growth? A. Fire A. Fire B. Flood B. Flood C. Windstorm C. Windstorm D. Drought D. Drought

A. Fire

The energy consumed by organisms A. Is not partially lost during digestion A. Is not partially lost during digestion B. Can be stored in fat and sugar molecules B. Can be stored in fat and sugar molecules C. Remains constant at all trophic levels C. Remains constant at all trophic levels D. undergoes magnification in food chains D. undergoes magnification in food chains

B. Can be stored in fat and sugar molecules

What type of vegetation would you expect to find on an abandoned farm that has remained undisturbed for 150 years A. Short grasses A. Short grasses B. Shrubs B. Shrubs C. Young pine trees C. Young pine trees D. Tall, mature oak trees D. Tall, mature oak trees

D. Tall, mature oak trees

Which of the following does NOT contain carbon from the bodies of plants and animals that died millions of years ago? A. Coal A. Coal B. Oil B. Oil C. Natural gas C. Natural gas D. Phosphate salts D. Phosphate salts

D. Phosphate salts

Which of the following are photosynthetic organisms? A. Intestinal bacteria A. Intestinal bacteria B. Freshwater algae B. Freshwater algae C. Deeply buried soil bacteria C. Deeply buried soil bacteria D. Fungal decomposers D. Fungal decomposers

B. Freshwater algae

Which of the following is responsible for making nitrogen in the atmosphere usable by living organisms? A. Nitrogen-fixing bacteria A. Nitrogen-fixing bacteria B. Absorption of nitrogen into water systems B. Absorption of nitrogen into water systems C. Decomposing bacteria C. Decomposing bacteria D. Conversion of nitrogen into carbohydrates by photosynthesis D. Conversion of nitrogen into carbohydrates by photosynthesis

A. Nitrogen-fixing bacteria

Which organism is likely to be in the bottom trophic level of a food chain? A. Leopard seal A. Leopard seal B. Algae B. Algae C. Krill C. Krill D. Killer whale D. Killer whale

B. Algae

Which of the following plants is likely to be a pioneer species? A. Grass A. Grass B. Shrub B. Shrub C. Lichen C. Lichen D. Oak tree D. Oak tree

C. Lichen

lichens are really fungi containing photosynthetic algal cells conveniently grouped into 3 characteristic growth forms: conveniently grouped into 3 characteristic growth forms: Foliose lichens have a leaf-like or lobed thallus, loosely attached to the substrate by root-like rhizines or by a central stalk-like umbilicus. Foliose lichens have a leaf-like or lobed thallus, loosely attached to the substrate by root-like rhizines or by a central stalk-like umbilicus. Fruticose lichens have an intricately branched upright or pendulous thallus. Fruticose lichens have an intricately branched upright or pendulous thallus. Crustose lichens are low-growing, with the entire thallus firmly attached to the rock or other substrate. Crustose lichens are low-growing, with the entire thallus firmly attached to the rock or other substrate. The thallus of crustose lichens may be squamulose (composed of crowded, overlapping scales) or areolate The thallus of crustose lichens may be squamulose (composed of crowded, overlapping scales) or areolate

Foliose lichen

Lichens as bioindicator Scientists use lichens as bioindicator species to assess air quality Scientists use lichens as bioindicator species to assess air quality Lichens vary in their ability to survive in areas exposed to pollutants such as sulfur dioxide, fluoride, and ammonia Lichens vary in their ability to survive in areas exposed to pollutants such as sulfur dioxide, fluoride, and ammonia They tend to concentrate heavy metals They tend to concentrate heavy metals Lichens also serve as recorders of these other contaminants. Lichens also serve as recorders of these other contaminants.

Lichens also have diminutive animals living on their surface called “water bears” peculiar fat body with stubby legs bearing claws at the tips

1 st stage- caused by some sort of disturbance 2 nd stage- colonizers like herbaceous plants take advantage of the improved soil by macroinverte- brates and microbes and weeds of the 1 st stage 3 rd stage- larger plants take over and compete for light – diversity increases 4 th stage- shrubs provide protection for tree seeds to grow 4 th stage- increase shade affects the growth of plants below, dead tree leaves produce humus lower the pH of the soil and herbs cannot grow, therefore conserving nutrients FINAL stage- Slow growing trees, community reaches its peak of productivity and diversity Community remains unchanged unless disturbed, and then SUCCESSION starts over again!

Succession A series of communities that develop in an area over time. A series of communities that develop in an area over time. OR Successions are changes in communities that happen over time OR Successions are changes in communities that happen over time If the succession develops from an area with no community, it is called a primary succession e.g. on exposed rock. If the succession develops from an area with no community, it is called a primary succession e.g. on exposed rock. If the succession develops from an area that has been prevented from changing e.g. by agriculture, it is called a secondary succession. If the succession develops from an area that has been prevented from changing e.g. by agriculture, it is called a secondary succession.

Primary colonisers Organisms that are able to colonize a disturbed habitat such as an area of bare soil or rock. Organisms that are able to colonize a disturbed habitat such as an area of bare soil or rock. They have adaptations that enable them to survive and reproduce in the harsh environment. They have adaptations that enable them to survive and reproduce in the harsh environment. Primary colonizers typically have effective methods of dispersal. Primary colonizers typically have effective methods of dispersal.

Climax community Succession eventually reaches a stable community called the climatic climax. Succession eventually reaches a stable community called the climatic climax. However, the structure of this community depends the soil and climate. However, the structure of this community depends the soil and climate. In the temperate forest biome, most successions lead to woodland. In the temperate forest biome, most successions lead to woodland.

Pioneer Some organisms are able to live in environments where there is no stable soil. Some organisms are able to live in environments where there is no stable soil. They have to be able to extract nutrients from the air and to attach themselves to the surface. They have to be able to extract nutrients from the air and to attach themselves to the surface. As they grow and produce dead matter, they start to develop soil and weather the surface. As they grow and produce dead matter, they start to develop soil and weather the surface. Other colonizers then start to grow in the area and the pioneers are rapidly out competed. Other colonizers then start to grow in the area and the pioneers are rapidly out competed. Lichens are an example of pioneers of bare rock. Lichens are an example of pioneers of bare rock.

Herbaceous A green plant that supports itself with its cell's turgor. A green plant that supports itself with its cell's turgor. Herbaceous plants are often dominant in the second stage in a succession. Herbaceous plants are often dominant in the second stage in a succession. Later stages become dominated by woody plants. Later stages become dominated by woody plants. The first stage is often dominated by other photosynthetic organisms such as algae and lichens. The first stage is often dominated by other photosynthetic organisms such as algae and lichens.

Diversity The diversity of living things in a habitat increases as the succession takes place. The diversity of living things in a habitat increases as the succession takes place. The developing soil enables a wider range of plants to colonize and they provide food and shelter for animals. The developing soil enables a wider range of plants to colonize and they provide food and shelter for animals. The animals in turn provide food for secondary consumers. The animals in turn provide food for secondary consumers.

Competition Competition is the primary factor that causes the change in communities in the succession. Competition is the primary factor that causes the change in communities in the succession. Each community of plants and animals alters the environment making it less suitable for them and more suitable for other colonizers. Each community of plants and animals alters the environment making it less suitable for them and more suitable for other colonizers.

Dune Succession

The sea deposits sand on the beach and the wind blows it inshore. The sea deposits sand on the beach and the wind blows it inshore. Objects on the strandline reduce wind speed and the sand is dropped. Objects on the strandline reduce wind speed and the sand is dropped. This embryo dune is a very disturbed habitat with an environment that few plants can colonize. This embryo dune is a very disturbed habitat with an environment that few plants can colonize.

A pioneer community – fast growing annuals w/xerophytic adaptations

Sea sandwort - small surface area and hairs on the lower surface reduce water loss

The succession from sand to a climax community The picture shows a dune system

A succession starting with open sand is a psammosere

A succession starting with bare rock is a lithosere

A halosere - starts with open salt water (e.g. the succession that may lead to a saltmarsh at the edge of an estuary)

A hydrosere develops from open freshwater (e.g. in a pond)

Agriculture - a large area of land is really a false climax caused by this activity

Human Development People spend a lot of time and money deflecting successions or halting them People spend a lot of time and money deflecting successions or halting them If this managed ecosystem is left undisturbed for a few years If this managed ecosystem is left undisturbed for a few years It will develop as a succession until it reaches the climatic climax It will develop as a succession until it reaches the climatic climax This is called secondary succession This is called secondary succession

Ecological Terms to Know Ecology Biotic Abiotic Environment Ecosystem

Ecological Terms to Know Community Population Succession Primary vs secondary succession Pioneer species

Climax community Invasive species Habitat Requirements for a good habitat Leading cause for extinction or endangerment of an organism Ecological Terms to Know