Week 11 - Biomes and Humans as Planetary Force

Global patterns

_______ _________ of primary production and biodiversity reflect climate, nutrient availability, and evolutionary history

Anthropocene

An epoch dominated by human impacts on the planet in which our foodprint is large

Photosynthesis

_________ uses sunlight to reduce CO2 to carbohydrates, while oxidizing water to O2.

respiration

__________ runs photosynthesis in reverse, making a cycle.

Sunlight, water, nutrients

Plant, algae, and photosynthetic bacteria productivity are limited by what three things?

iron

_____ is needed for enzymes, and is limiting rates of photosynthesis in some parts of the oceans

Limited

We know iron limits primary production because when it is not in the water, growth is _____

Liebig’s Law of the Minimum

Which law states: Primary production is limited by the nutrient that is least available to the needs of primary producers

Latitudinal diversity gradient

Species diversity in terrestrial vascular plants, animals, birds, and insects highest near equator, declines to poles.

more

Where there are more plant species, there are ____ mammal, insect, and bird species

carbon foodprint

As standard of living increases so does a countries ______ _______

Fossil Fuels

Burning (oxidizing) ancient organic matter into CO2

Fossil fuels and land use change

Carbon is being moved between reservoirs because of these two factors

Agriculture, livestock, natural gas

What are three major human sources of carbon?

thawing permafrost and wetlands

What are two major natural sources of carbon?

composition

Because biome __________ is driven by climate, they are affected by warming temperatures

fitness

Rapid environmental change poses new ______ challenges on species that must now adapt to a new environment, Some will and and some won’t.

Short

Increases CO2 affects plants in the _____-term through:

• changes in physiology of plants

• less N in tissues

• lower energy to reproduction

Long

Increases CO2 affects plants in the _____-term through:

• natural selection

• changing allele frequencies in survivors

waters warming

One of the deadly trio in the worlds oceans:

• challenge to species already at upper thermal limits (e.g. marine mammals)

• affecting primary producers and their consumers

• bleaching of coral reefs (symbiont algae leaving hosts)

• oceans rising

Ocean absorbing more CO2

One of the deadly trio in the worlds oceans:

• Dissolves to form carbonic acid

• leads to ocean acidification (decreased pH)

• Drop of 0.1 pH units = 30% increase in H ions

• Trend will continue as atmospheric CO2 rises

Capacity to store O2 is reduced

One of the deadly trio in the worlds oceans:

• warmer wanters hold less oxygen

• being observed in oceans

• threatens animal species