Phosphate is often the limiting plant nutrient in soil, and perhaps the evolutionary pressure to conserve phosphate for more critical roles favored plants that made phosphate-free lipids.

TLS Online TPP Program

#Id: 5368

#Unit 10. Ecological Principles

The simplest method to measure population density is to visually count the number of organisms in a population in a given habitat.

TLS Online TPP Program

#Id: 5369

#Unit 10. Ecological Principles

Quadrats - A square frame often, but not always, measuring 50 × 50 cm. 

TLS Online TPP Program

#Id: 5371

#Unit 10. Ecological Principles

Pitfall traps set into the ground catch wandering species such as beetles and spiders. These have rain covers to prevent the animals from drowning

 

TLS Online TPP Program

#Id: 5372

#Unit 10. Ecological Principles

Baited snap traps, Population density can thus be estimated as the number of animals caught per trap or per unit area where a given number of traps are set.

TLS Online TPP Program

#Id: 5373

#Unit 10. Ecological Principles

The mark-recapture technique is that after the tagged animals are released, they mix freely with unmarked individuals. The population is resampled and the numbers of marked and unmarked individuals are recorded. 

TLS Online TPP Program

#Id: 5374

#Unit 10. Ecological Principles