Energy and the Environment Exam 2

ecosystem

consists of all the organisms living in a community, as well as the abiotic (non-living) factors with which they interact

• range from small (aquarium) to large (lake or forest)

What controls processes in ecosystems?

energy provided by the ☼

Earth’s energy budget

• 30% of incoming energy reflected back into space by clouds or Earth’s surface

• 19% absorbed by atmosphere/clouds

• 51% absorbed by land or water (oceans)

photosynthesis

energy from the sun drives this process, where the sun’s energy is converted into chemical energy (glucose or sugar)

producer

an organism that makes its own energy-rich food compounds using the sun’s energy

major producers on land

green plants

• contain chlorophyll, which captures light energy

areas that ecosystems can cover

• very large areas like the Amazon Rainforest

• very small areas like a tidal pool

three types of ecosystems

1. freshwater - least common (1.8%); examples: lakes, rivers, and streams

2. marine - most common (75%); 3 types: shallow ocean, deep ocean, and deep ocean bottom

3. terrestrial - one land; known for its wide diversity

   • biome (related to terrestrial) - large-scale community of organisms mainly defined by plant type (ex: tropical rainforest, desert, and tundra)

food chains

linear sequence of organisms through which nutrients and energy pass as one organism eats another

levels in the food chain

1. producers

2. primary consumers - living creatures that eat plants

3. higher-level consumers - living creatures that eat primary consumers

4. decomposers

decomposers

fungi and bacteria that consume dead plants and animals

trophic levels

different levels of the producers and consumers

How is energy for food chains provided?

through the sun

• light, chemical, and mechanical/heat energy

food web (all the food chains in an ecosystem)

• carnivores - meat eaters

• herbivores - plant eaters

• omnivores - meat and plant eaters

Who can be part of the food chain?

humans —> can be carnivores, herbivores, or omnivores (cheaper to support herbivores)

• energy dynamics of ecosystems have important implications for human populations

calorie

energy needed to raise the temperature of 1 gram of water 1 degree centigrade

corn example

consuming corn directly is much more efficient than corn fed beef

biochemical cycling

an important process in energy flow through ecosystems

cycles related to biochemical cycling

1. water (hydrologic) cycle

2. carbon cycle

3. nitrogen cycle

4. phosphorus cycle

5. sulphur cycle

biogeochemical cycles

nutrient cycles in ecosystems that involve biotic and abiotic components

• provide/involve energy flow through ecosystems and influence why life can exist on Earth

Which elements occur in the atmosphere and biogeochemical cycle globally?

gaseous carbon, oxygen, sulfur, and nitrogen

water (hydrologic) cycle

a driving mechanism for making each of the cycles work

• possesses important processes that drive that cycle and thus the flow of energy through ecosystems

• interrelated processes that release and transfer energy through ecosystems (atmosphere, ocean, and land)

three forms water exists within the water cycle

1. solid (ice)

2. liquid (liquid water)

3. gas (water vapor or gaseous vapor)

What is required for water to change forms?

energy —> it is released as part of the process of changing forms

evaporation

a process where a liquid (water) changes from its liquid state to a gaseous state (water vapor)

• the gaseous water vapor is lifted (rises) in the atmosphere because it is in this gaseous state

condensation

the opposite of evaporation; occurs when a gas is changed into a liquid

• when the water droplets formed from condensation are very small, they remain suspended in the atmosphere, and when they get large enough, they fall as precipitation

• these millions of droplets of suspended water form clouds in the sky or fog at the ground level

precipitation

when the temperature and atmospheric pressure are right, the small droplets of water in clouds form larger droplets and precipitation occurs; the raindrops fall to the Earth

When precipitation falls in the ocean or other bodies of water,…

…evaporation occurs again.

temperature in the atmosphere

this controls whether the precipitation is in the form of rain, sleet, or snow

surface runoff

this is formed when precipitation falls on the land and gets into stream systems, soaks into the ground, or flows across the surface of the earth

• streams generally merge together, forming larger streams, and eventually flow into a large body of water like a lake, or more commonly the ocean

percolation

water that soaks into the ground, into the soil and underlying rock layers

• water in the soil can be used by plants or it gets below the plant roots, continuing to move downward

infiltration

a process that helps the water from percolation continue to move downward below the root zone, eventually providing water to the Earth’s groundwater

groundwater

water stored naturally beneath the surface of the Earth that filters out many of the impurities in the water, cleaning the water thoroughly

aquifiers

water that recharges areas beneath the surface of the Earth

• if you live in a rural area, your well taps into these, the naturally stored groundwater for the Earth

transpiration

the final and important process of the water cycle

• occurs when plant roots take in water

• then, the plant extracts the nutrients for the water and gives off excess water through the leaves

• the water on the leaves evaporates back up into the atmosphere as part of the water cycle

carbon cycle

carbon molecules are stored or used as part of ecosystems

• photosynthesis is part of the cycle in which plants take in solar energy and release oxygen back into the atmosphere

• excess carbon dioxide can build up in the atmosphere during the cycle

carbon cycles through ecosystems by plants by…

…gaining nutrients from photosynthesis and by plants being eaten by primary consumers and other higher-level consumers eating lower-level consumers

greenhouse effect

• the direct relationship between how much carbon is in the atmosphere and global atmospheric temperatures

• the more carbon in the atmosphere, the more emitted solar energy that is held in the atmosphere and the warmer the atmosphere

greenhouse gases that hold heat in the atmosphere

• carbon dioxide

• methane

• nitrous oxide

• fluorinated gases

human impacts on the carbon cycle

Solutions:

• Less deforestation

• Plant more trees

• Driving less cars

• Burning cleaner fuels

• Producing less industrial emissions

• Producing cleaner emissions

cycles similar to the carbon cycle

phosphorus cycle and sulphur cycle

nitrogen cycle

• nitrogen is a component of amino acids, proteins, and nucleic acid

• the main reservoir of nitrogen is the atmosphere (N2), but this nitrogen must be converted to NH4+ (ammonia) or NO3- (nitrate) for uptake by plants, via nitrogen fixation by bacteria

phosphorus cycle

• phosphate is the most important inorganic form of phosphorus

• the largest reservoirs are sedimentary rocks of marine origin, the oceans, and organisms

• drives energy flow through ecosystems

sulfur cycle

• a component of most proteins and some vitamins

• sulfate ions (SO4 2-) dissolved in water are common in plant tissue. They are part of sulfur-containing amino acids that are building blocks for proteins.

• sulfur bonds give the three-dimensional structure of amino acids

• many animals, including humans, depend on plants for sulfur-containing amino acids

• it also drives energy flow through ecosystems

   

maintaining sustainable ecosystems

• natural captial of ecosystems combines to keep species alive

• natural resources are the useful materials and energy in an ecosystem

• natural services are important natural processes such as renewal of air, water, and soil resources in ecosystems that lead to healthy ecosystems

• in addition, economics, politics, and ethics all combine to maintain healthy ecosystems

• the design of our economic and social systems and individual lifestyles help maintain ecosystem services

structural levels of a forest

• canopy

• understory

• soils

factors that make a forest unique

• soil

  • contains minerals, water, nutrients, and air

• water

  • rainfall soaks into the soil, dissolves chemicals, in soil, forms water solutions, and nourishes plants

• nutrients

  • transpiration - moves from soil, to roots, to leaves, and lastly to the atmosphere

• air (soil air)

  • important because of its relationship with soil water (more air, less water)

  • soil air hosts for organisms and bacteria that aid in decomposition

• sunlight

  • important as part of the photosynthesis process, nourishing plants, and exchanging energy

Which site specific conditions affect what forest community ecosystem develops?

soil, water, nutrients, and general climate

• in turn, this controls what type of forest grows where

climate

the biggest controlling factor regarding what type of forest grows where

• forests as part of their management are inventoried based on species type and distribution

forest floors

• dominated by litter with dead leaves and branches which decompose to add nutrients to the soil and breaks down because of bacteria

forest succession

at times in the life cycle of a forest, they evolve from grasses to shrubs to forest and back to grasses (measured on a scale of hundreds of years)

• primary succession - first stage of forest evolution

  • Pioneer Species —> Intermediate Species —> Climax Community

• secondary succession - climax community (very mature forest) goes through a forest perturbation

perturbation

triggers change in a forest which can lead to a secondary succession; it’s like the forest starts over from scratch

• example: forest fire —> leads to a secondary succession and begins again with a primary succession

humans and urban ecosystems

• humans modify urban ecosystems and urban ecosystems effect human activity

• humans strive to maintain urban ecosystem services

• humans have not always lived in concentrated populations (urban areas)

• humans have gone from rural lifestyle to small urban to large urban to mega (huge) cities of today

Who has been informed to assist in maintaining the environmental integrity of urban ecosystems?

both government and non-government (NGO) organizations

the growth of urban areas is sometimes known as…

…industrialization of those areas

Up to 200 years ago, how much of the world’s population lived in urban areas?

less than 5%

Urban populations have been growing rapidly since the…

…Industrial Revolution

By 2022, how much of the world’s population live in urban areas?

over 57% or 4.5 billion people

concentrating populations leads to impacts on…

…urban areas

• leads to problems with soil damage, flooding, waste disposal, and energy demand

urban ecology

• the study of ecosystems that include humans living in cities and urbanizing landscapes

• studies how concentrated human populations effect the Earth

how humans occupy and settle a city occurs in patterns…

…the economically disadvantaged populations live in slums that often ring the downtown business section of a city

• these settlement patterns lead to problems associated with maintaining urban ecosystem services like…

  • maintaining quality drinking water supplies

  • adequate waste disposal

  • declines in biodiversity

  • reducing noise pollution

  • urban heat island effect

As human populations expand, what becomes more important?

maintaining, preserving, and conserving urban ecosystem services

Changed ecosystem services can lead to…

…stormwater runoff and flooding

What leads to many problems in urban areas?

the creation of impervious surface

Urbanization also leads to the destruction of natural areas in a city,…

…which directly correlates with the creation of impermeable surfaces like streets, roof tops, and parking lots

urban heat island effect

human-constructed objects absorb heat in urban areas and then give off that heat, making the urban area warmer

biophilia

an innate and genetically determined love for the natural world felt universally by humankind

• the concept was developed to express ways for humans to more adequately connect with nature in urban areas

• there are six hypotheses to express how humans can best connect with nature and improve the human living conditions in an urban area

greenspaces

• absorbs partials for the air

• beautifies the space

• provides habitat

• reduces noise pollution

• cleans water

• encourages healthy outdoor activities

Pittsburgh as an urban ecosystem

benefits the city and its inhabitants by…

• cooling the city

• storing excess carbon

• mitigating storm water runoff

• improving water quality

the political ecology of uneven urban greenspace

• uneven distribution of greenspace

• less greenspace in economically disadvantaged areas

• socio-environmental bias regarding the creation of new greenspace

• areas with high minority populations lack greenspace

biodiversity

• bio - life

• diversity - variety

• describes the variety of biological organisms in a given habitat, area, or ecosystem

habitat

natural home or environment of an animal, plant, or other organism

• examples: forests, deserts, wetlands, rainforests

case study

used to study the biodiversity of ecosystems

• can be conducted that study a single ecosystem like a pond and its surrounding area

• often focus on a problem associated with an ecosystem

triggers that lead to problems in ecosystems

• habitat loss

• drought

• more solar radiation

• parasites

• diseases

• pollution

• climate change

Which species face a 33% probability of extinction because of a combination of these problems in ecosystems?

amphibians

biodiversity importance

• all species (even humans) depend on each other to survive

• the loss of biodiversity leads to the loss of ecosystem services that benefit society

• greatly effects ecosystem services and sustaining life on Earth

three types of biodiversity

1. Genetic diversity – differences in DNA among individuals

   • The greater the genetic diversity, the higher the chance of a long-term survival

2. Species diversity – a variety of species in a given area

   • A set of individuals that can mate and produce fertile offspring

   • An estimate is that there are 10-14 million species in total

   • 2 million species identified

   • tropical rainforests contain about 50% of the species that are projected to live on Earth

3. Ecosystem diversity – a variety of habitats, ecosystems, and related communities

   • Biomes – regions of the world with similar climate, animals, and plants

     • Earth can be divided into major biomes —> The existence of these biomes depends on various diversity concepts within biodiversity

     • Distinct climate

     • Certain species, especially vegetation

functional diversity

• The variety of processes, including matter cycling and energy flow within ecosystems, that result from species interacting with one another in food webs

• Spatial variations in diversity are controlled by climate

climate as a major controlling influence on how an ecosystem develops

• example: the volume of precipitation that falls in a given area

• variabilities in climate can influence the formation of rain shadows, which is related to where a desert will form

  • when moist air is lifted over mountains, the precipitation falls in the mountains

  • by the time the air gets to the other side of the mountains, it is very dry and a desert will form in that location

insects playing a vital role as part of ecosystems

• help pollinate plants

• renew soils

• serve to control certain pests

mutations and natural selection

• causes ecosystems to change and evolve over time

• mutations of changes to organisms at the genetic level

• natural selection - the most well-adapted species survive and the less adapted die off and go extinct

  • can happen at the microscopic level

  • adaptive traits - genetically favorable traits that increase the probability to survive and reproduce

  • trait - heritable and lead to differential reproduction

the Earth’s fossil record

indicator of how life on Earth has changed and evolved over time

long term changes in the Earth’s climate influences natural selection

• the Florida example: shows a changing area and species based on climate change and related effects

mass extinction

• when an entire species goes extinct

• there also can be local extinctions

species richness

the number of a given species within a defined region

• varies with where you are on Earth/geographic location

diverse ecosystems contribute to…

• healthy ecosystems

• healthy humans

• healthy economies

a healthy and diverse ecosystem plays a vital role in maintaining soil, water, and air quality

triggers for biodiversity loss

• habitat loss

• overexploitation

• climate change associated with global warming

• pollution

• invasive species