Final Exam Bio 260

What is the green world hypothesis? 

The green world hypothesis says that herbivores consume relatively little plant biomass because they are held in check by a variety of factors including predators Parasites and diseases  

What are top-down processes? Bottom-up? 

In a top-down approach, the Predator controls the tropic Cascade while in a bottom-up approach the producers control the tropic cascade 

From a top-down approach, the world is prickly and tastes bad 

What is the Theory of Island Biogeography? Explain what was learned. 

Distance (Isolation) matters as much as area in predicting species of richness.

Distance controls immigration rates Area controls extinction rate  

more area you have more richness

Extinction rate is higher on small islands

Extension rate is lower on bigger islands

How does species richness vary? In which directions? 

In higher latitudes, there tends to be less species of richness. In addition to that in higher elevations there tends to be less species richness 

What is NPP? And how it is different from GPP? 

Net Primary Productivity is energy left after plants breath

Gross Primary Productivity is total amount of Carbon Fixed by autotrophs 

Which ecosystems have low/high NPP? Why? 

High NPP is found in the tropical Rainforests this is because there is a lot of energy in these areas there is also a significant amount of biodiversity

Low NPP Deserts/Tundra these areas have extremely low plant life water and sunlight where Net Primary productivity is physical and biotic these values are going to be low

What factors influence trophic levels? How? 

energy availability each species that eats the species in the topic level below it only gains 10% of its energy