BI303 - Section 1 Lecture 6

What is the dominant vegetation type in many areas with sand, gravel, or rock?

Succulent grasses and herbs

Which type of vegetation is found in the Americas?

Cactus

Where is Euphorbia found?

Africa and Asia

Where is vegetation usualy found in arid regions?

In depressions or above aquifers

What is the soil structure in arid regions?

Poorly formed or absent

What is the climate characteristic of arid regions?

Hot summers, cool/freezing winters

What is the average annual rainfall in arid regions?

Less than 5 cm

What is the net annual productivity in arid regions?

315 Kcal m-2 yr-1

What is the dominant vegetation type in the dry tropical forest biome?

Semi-deciduous trees and C4 grasses

What is an example of a tree found in the dry tropical forest biome?

Baobab (Adansonia)

What is the vegetation structure in the dry tropical forest biome?

Scattered open canopy and shrub layer

What is the soil structure in the dry tropical forest biome?

Moderate depth, variable fertility

What is the climate characteristic of the dry tropical forest biome?

Hot summers, mild winters

What is the average annual rainfall in the dry tropical forest biome?

100-200 cm, seasonal

What is the net annual productivity in the dry tropical forest biome?

7000 Kcal m-2 yr-1

What are the characteristics of dry tropical forests and savannas?

Constant state of change.
Common fires during long dry seasons.
Greates vertebrate biomass of any biome.
Seasonal herbivore migrations triggered by monsoon winds.

What is a notable migration pattern in the Serengeti?

Wildebeest migrate south during wet season

How far do wildebeest migrate daily in the Serengeti?

4-5 km

How do carnivores behave in the Serengeti compared to herbivores?

Carnivores are more territorial and less mobile

What factors influence the distribution of forest and grassland areas?

Rainfall, fire, grazing and predator density

What is the impact of elephant grazing in Africa and India?

Key driver of habitat change.
Influences forest and grassland distrubution.
Contributes to shifting mosaic landscapes.

What happens over time due to seasonal fires and elephant grazing?

Shifring of forest habitats across the landscape

What is a riverbank habitat's characteristic compared to forest habitats?

More fixed feature of the landscape.

What effect does the absence of fire and grazing have on forests?

Allows new forest to establish

What is the net annual productivity of tropical rainforests?

9000 Kcal m-2 yr-1

What is the primary role of tropical rainforests in global ecosystesm?

Core role in water and carbon cycles

What is the climate characteristic of tropical rainforests?

Hot all year round

What is the average annual rainfall in tropical rainforests?

More than 150 cm

What has happened to rainforests aroudn the Indian Ocean and SE Asia?

Mostly destroyed, deforestation accelerating

What are the characteristics of the mountain zone?

High altidue habitats in every biome.
Elevational ecologial gradient similar to latitudinal gradient.
Higher species endemism due to restricted habitats.
More susceptible to disturbance and climate change.

What is an example of a mountain range that contains multiple biomes?

North American, Rocky Mountains

What adaptation do tropical alpine plants have?

Specialised frost-protection growth form

Where are apline species in Europe typically found?

Above the treeline in harsh conditions

What is the vertical distribution of habitats like in the European Alps?

Repeated across the Alps region

What is the surrounding habitat of tropical alpine plants?

Tropical rainforest and glaciers

How does the distribution of alpine species relate to their environment?

Restricted to narrow ranges due to altitude

What is the impact of climate change on mountain habitats?

More susceptible to disturbance and destruction