global environmental controls of diversity in large herbivores

Global environmental controls of diversity in large herbivores

Han Olff, Mark E. Ritchie & Herbert H.T. Prins

1) Where a herbivore can survive is controlled by available resources: particularly plant abundance and quality.

2) Plant abundance and quality is controlled by available water and soil nutrients.

So, is it possible to predict where a herbivore can survive based only on available water and nutrients?

Assumption 1

1) Plant abundance increases with increased moisture and nutrients.

Assumption 22) Plant quality decreases with increased

moisture but increases with increased nutrients.

Assumption 33) Large herbivores can persist in areas where plant quality

is low if plant abundance is high.

Assumption 4

4) Small herbivores can survive in areas where plant abundance is low if plant quality is high.

Plant abundance

(low)

Abundance threshold

(high)

herbivore persists

Plant quality

quality threshold

(low)

herbivore persists(high)

Together…

Herbivore persists

High nutrients

Intermediate moisture

Is diversity highest at intermediate plant available moisture?

Is herbivore diversity highest at high nutrients?

(Myers et al. 2000 (Nature))

Biodiversity hotspots for conservation priorities…