IndividualsEnergyandnutrientrelations40On average,ahigherproportionof tropicalplantspeciesbeartoxic alkaloids,apotentdefense30againstpotential herbivorese20100TemperateTropicalToxic alkaloidsRegionFIGURE6.10Proportionof temperateandtropical plantsbearingtoxic alkaloids (data from Coley and Aide 1991)
Individuals Energy and nutrient relations Toxic alkaloids
IndividualsEnergyandnutrientrelationsWhenresearchers presentedtemperate and tropical seaweedsin equal amounts,urchins atetwice as much temperate seaweed60(%）二what do the sea urchinsooooeatpreference?20TemperateTropicalFIGURE6.11Sea urchin preference for temperate versus tropical seaweeds (datafromBolserand Hayi996)
Individuals Energy and nutrient relations what do the sea urchins eat preference?