Chapter 4 Part 2: The Living World: Ecosystems and Biodiversity

Humans

________ have affected the phosphorus cycle by mining phosphorus- rich rocks in order to produce fertilizers.

Human disruptions

________ to ecosystem services can detrimentally affect our ability to benefit from them, resulting in ecological and economic consequences for us.

NPP

________ is measured in kilocalories per square meter per year (kcal /m2 /y)

Saprotrophs

________: These are decomposers that use enzymes to break down dead organisms and absorb the nutrients; they include bacteria and fungi.

Species of plants

________ and animals are continually coming and going, evolving and dying out.

trophic level

The amount of energy (in kilocalories) available at each ________ organized from greatest to least is an energy pyramid.

Breathe

________ in oxygen and give off carbon dioxide, and photosynthesis, in which plants take in carbon dioxide, water, and energy from the sun to produce carbohydrates.

Detritivores

________: The organisms in this group derive energy from consuming nonliving organic matter such as dead animals or fallen leaves.

medicinal resources

There are four categories: provisioning services: providing humans with water, food, ________, raw materials, energy, and ornaments; regulating services: waste decomposition and detoxification, purification of water and air, pest and disease control and regulation of prey populations through predation, and carbon sequestration; cultural services: use of nature for science and education, therapeutic and recreational uses, and spiritual and cultural uses; and supporting services (the ones that make other services possible): primary production, nutrient recycling, soil formation, and pollination.

net productivity

A disturbance in an ecosystem will affect the total biomass, species richness, and ________ over time.

Nitrogen

________ is the most abundant element in the atmosphere.

Phosphates

________ that enter the water table and travel to the oceans can eventually be incorporated into rocks in the ocean floor.

Phosphorus

________ is usually released in the form of phosphate (PO43),- which is soluble and can be absorbed from the soil by plants.

human activity

When sulfur enters the atmosphere through ________, its mainly via industrial processes that produce sulfur dioxide (SO2) and hydrogen sulfide (H2S) gases.

Animals

________ obtain sulfur by consuming plants.

enormous scales

When big changes occur in the environment, habitats can change on ________, which in turn can cause extinctions, bottlenecks, and short- and long- term migrations among the species inhabiting the affected ecosystems.

Food webs

________ contain positive and negative feedback loops, so that when one species is added or removed, the rest of the ________ is affected, sometimes drastically.

volcanic eruptions

The natural ways that sulfur enters the atmosphere are through ________, certain bacterial functions, decomposition in estuaries, and the decay of once- living organisms.

inorganic chemicals

While most producers make food through photosynthesis, a few autotrophs make food from ________ in anaerobic (without oxygen) environments, through the process of chemosynthesis.

nitrites

In denitrification, specialized bacteria (mostly anaerobic bacteria) convert ammonia back into ________ and nitrates, and then into nitrogen gas (N) and nitrous oxide.

Eutrophication

________ occurs when a body of water receives excess nutrients.

disappearance of trout

The ________ from a particular habitat is a warning that that habitat is becoming polluted.

Indigenous species

________ are those that originate and live or occur naturally in an area or environment.

Chemosynthesis

________ is only carried out by a few specialized bacteria, called chemotrophs, some of which are found in hydrothermal vents deep in the ocean.

Decomposers

________: These are organisms that consume dead plant and animal material.

Gross Primary Productivity

It is calculated by taking the ________, which is the amount of sugar that the plants produce in photosynthesis, and subtracting from it the amount of energy the plants need for growth, maintenance, repair, and reproduction.

Net Primary Productivity

The ________ (NPP) is the amount of energy that plants pass on to the community of herbivores in an ecosystem.

Producers

________ are organisms that are capable of converting radiant energy, or chemical energy, into carbohydrates.

Earths atmosphere

The ________ is made up of approximately 78 percent nitrogen and 21 percent oxygen.

large proportion

When a(n) ________ of a population is lost, this leads to a bottleneck, which can reduce genetic diversity within the species.

term biodiversity

The ________ is used to describe the number and variety of organisms found within a specified geographic region, or ecosystem.

Lichens

________ are pioneer organisms.

Consumers

________ are organisms that must obtain food energy from secondary sources, for example, by eating plant or animal matter.

Sulfur

________ is one of the components that make up proteins and vitamins, so plants and animals both need ________ in their diets.

primary consumer

When eating a hamburger with toppings, you are a(n) ________ because you are eating tomatoes and lettuce, and a secondary consumer by eating the beef.

Trout

________ are a common indicator species, because they are particularly sensitive to pollutants in water.

Food chains

________ are usually represented as a series of steps, in which the bottom step is the producer and the top step is a secondary or tertiary consumer.

net productivity

It can be many things: space, available food, water, nutrients, and as we just mentioned, the ________ of an ecosystem.

food webs

When something changes in an ecosystem, the effects of that change can quickly spread, partly because ________ link species together.

Lichens

________ are hardy organisms.

Gross Primary Productivity

In other words, the ________ of an ecosystem is the rate at which the producers are converting solar energy to chemical energy (or, in a hydrothermal ecosystem, the rate of productivity of the chemotrophs)

One aspect of the carbon cycle that you should definitely be familiar with for the exam is this

when the bodies of once-living organisms are buried deep and subjected to conditions of extreme heat and extreme pressure, this organic matter eventually becomes oil, coal, and gas

There are three major reservoirs of carbon

the first is the world's oceans, because CO, is very soluble in water

Step 1

Nitrogen fixation In order to be used by most living organisms, nitrogen must be present in the form of ammonia (NH,) or nitrates (NO)

Step 2

Nitrification-In this process, soil bacteria converts ammonia (NH) or ammonium (NH) into nitrites (NO,) and then to one of the forms that can be used by plants nitrate (NO,)

Step 3

Assimilation-In assimilation, plants absorb ammonium (NH), ammonia ions (NH), and nitrate ions (NO,) through their roots

Step 4

AmmonificationIn this process, decomposing bacteria convert dead organisms and other waste to ammonia (NH) or ammonium ions (NH), which can be reused by plants or volatilized (released into the atmosphere)

Step 5

Denitrification gas (N,O)

There are actually two fancy terms that are normally used to describe these broad categories of organisms

autotrophs are those organisms that can produce their own organic compounds from inorganic chemicals, while heterotrophs obtain food energy by consuming other organisms or products created by other organisms

It can be many things

space, available food, water, nutrients, and as we just mentioned, the net productivity of an ecosystem

Primary consumers

This category includes the herbivores, which consume only producers (plants and algae)

Secondary consumers

An organism that consumes a primary consumer is a secondary consumer

Tertiary consumers

An organism that consumes a secondary consumer is a tertiary consumer

Detritivores

The organisms in this group derive energy from consuming nonliving organic matter such as dead animals or fallen leaves

Decomposers

These are organisms that consume dead plant and animal material

Saprotrophs

These are decomposers that use enzymes to break down dead organisms and absorb the nutrients; they include bacteria and fungi

As you probably recall, energy flows in one direction through ecosystems

from the sun to producers, to primary consumers, to secondary consumers, to tertiary consumers

One final note about food chains

in a food chain, only about 10% of the energy is transferred from one level to the next

One special case of the interrelatedness of habitat, biodiversity, and adaptation is the theory of island biogeography, which is a field that studies species richness and diversification in isolated communities

oceanic islands, and also other isolated ecosystems, such as mountain peaks, oases, seamounts, and fragments of habitat separated by human development

The number of species found on an island or in an isolated area is determined by two factors

immigration and extinction

When big changes occur in the environment, habitats can change on enormous scales, which in turn can cause extinctions, bottlenecks, and short

and long-term migrations among the species inhabiting the affected ecosystems