Ecology homework help

I have two questions the first one needs to be a minimum of 200 words and the second a minimum of 75 words.  Please clearly read the questions and be very detailed.
 
Describe the effects of temperature, moisture, length of photosynthetic period, and nutrient availability on net primary productivity in terrestrial ecosystems. Give examples in your explanations. (200 words)
First describe three ways that nutrients can be lost from an ecosystem; then describe how nutrients are replaced in those systems. (75 words)