geography paper help, 3 pages!

Generally, pioneer species:

1. Grow rapidly

2. Tend to be shade-intolerant

3. Have seeds that are widely dispersed

4. All of the above

5. None of the above

Generally, from early to mid-succession, an ecosystem experiences:

1. An increase in diversity and a decrease in biomass

2. An increase in diversity and an increase in biomass

3. A decrease in diversity and a decrease in biomass

4. No change in either diversity or biomass

Recap: Trees use a network of soil fungi to

communicate their needs, send warning

signals about environmental change,s and

transfer carbon and nutrients to neighboring

plants before they die. (See Radiolab podcast for 10/31)

 So what? Why does this matter?

Case study: amazonia

Synergy in Disturbance

Synergies are interactions between disturbances (and chronic situations) that impact landscape dynamics

Example: flooding  insect invasions

Deforestation in the Amazon

Deforestation: Causal factors

• Logging (both legal and illegal)

• Expansion of industrial agriculture: oil palm, livestock,

soybeans

• Government-sponsored settlement and colonization

programs

• Long history of unequal land ownership in Brazil

• Poor tropical rainforest soils encourage continued

clearing and burning

Despite the tremendous

biomass and biodiversity of

rainforests, their soils are

actually quite nutrient-poor

and infertile. Why?

Nutrient leaching!

Issue 1: changes in land cover (deforestation)

PASTURE LOGGED, SECOND-GROWTH INTACT

Relative Humidity 85%

Avg Temperature 28C

% Closed Canopy 85%

Relative Humidity 50%

Avg Temperature 38C

% Closed Canopy 5%

Relative Humidity 60%

Avg Temperature 33C

% Closed Canopy 50%

How much water vapor is absorbed into the atmosphere from a forest

or tree. Amazon = some of the highest Et rates in the world!

the “vegetation breeze” phenomenon

• Convective process that pumps moisture out of the ecosystem, leaving it warmer, dryer, and more susceptible to fire

Warmer temps, rising air

Changes in land cover 

Changes in the regional forest-climate system 

Changes in land cover

Global climate change!

So how does this relate to fire?

Surface fires in eastern Amazon, Brazil

What does this graph indicate?

Role of El Niño: drought and fire