What is Biosphere 2?How is it related to the Biosphere on Earth?

Do Now

ENGINEERING EARTH

A desert experiment gone awry

CHAPTER 6 ECOSYSTEMS AND NUTRIENT CYCLING

WHAT IS THE BIOSPHERE?

The total area on Earth where living things are

found.

The biosphere is basically the sum of all ____________ in a given area, representing all the organisms in that area as well as the physical environment in which they interact.

A. habitatsB. ecosystemsC. biomesD. communities

Clicker Question

HOW IS LIFE IN THE BIOSPHERE ORGANIZED?

HOW DOES THE BIOSPHERE FUNCTION?

The biosphere functions through two fundamental processes:

energy flow and nutrient cycling.

The Earth is energetically open but materially closed.

WHAT IS A BIOME?

A biome is a distinctive type of ecosystem determined by climate and identified by the predominant vegetation and organisms that have adapted to live there.

HOW MANY DIFFERENT BIOMES ARE THERE?

Biomes can be divided into three main types — terrestrial, marine, and

freshwater.  

Within these categories are several subgroups.

How was Biosphere 2 designed to mimic the biosphere?

Do Now

• How was the Biosphere 2 designed to mimic Earths biosphere?

• What did the study accomplish?• What went wrong, and what lessons

can be learned for future similar experiments?

BIOSPHERE BIOSPHERE 2

The biosphere is a large and complex system with many different biomes and ecosystems that all contribute to overall function.

Biosphere 2 also has several biomes contributing to overall function. But being approximately 3 acres in area, the challenge was including a variety of biomes in such close proximity.

WHY ARE BIOMES FUNCTIONALLY SIMILAR

BUT DIFFERENT IN THEIR SPECIES MEMBERSHIP?

Species within each biome are specifically adapted to the particular environmental conditions of that biome.

Range of tolerance: The range of a limiting factorwithin which a species can survive and reproduce.

Limiting factor: The critical resource whose availability determines species population size distribution.

WHY DID BIOSPHERE 2

FAIL?The likely culprit: the failure of nutrient cycles.

WHAT ARE NUTRIENT CYCLES?

The movement of nutrients such as carbon, nitrogen, and phosphorous through

the abiotic and biotic components of ecosystems.

AtmosphereHydrosphereLithosphere

ProducersConsumers

DecomposersLower than

normal ozone levels in the atmosphere

CFCs might be causing the

ozone to disappear

Abiotic Reservoirs

Biotic Reservoirs

Processes that cycle carbon

Do Now

• How are the biogeochemical nutrient cycles different from one another? How are they similar?

• In what ways do human activities affect the nutrient cycling process?

Carbon Cycle

Nitrogen Cycle

Phosphorous Cycle

How nutrient cycling failed in Biosphere 2

How human activities interfere withnutrient cycling in the biosphere

Reduces carbon uptake from atmosphere into biotic reservoirs

Releases carbon, and nitrogen from fossil fuel sinks into the atmosphere

Adds phosphorous and nitrogen to the hydrosphere, where it is a limiting factor

So what can we learn from Biosphere 2?

But learning how they function can help us restore degraded ones.

Ecosystems are

complicated

But learning how our actions affect it can help us change course.

The biosphere

is irreplaceabl

e

“Isolating small pieces of large biomes and juxtaposing them in an artificial enclosure changed their functioning and interactions, rather than creating a small working earth as originally intended.”

–Science magazine