Question

Organisms are found in places where their performance curves overlap environmental conditions. Indeed, most of the examples show that temperature and water (remember chapters 5 & 6) limit species’ distributions. However, biotic interactions (such as feeding, pollinating, or competing) can further influence where a species is found, generally making the realized niche smaller than the fundamental niche. For each of the following examples, select whether it reveals a fundamental or realized niche

a.) No kangaroo species is able to inhabit northern Australia because the hot, dry conditions do not allow suitable plants to grow that kangaroos use as food (fundamental or realized niche)

b.)Throughout their range, a species of tiger beetle prefers the same temperature. fundamental or realized niche?

c.) Some desert plants are only found in microhabitats with high soil moisture availability, because they avoid extreme high temperatures through evaporative cooling.  fundamental or realized niche?

d.) Balanus barnacles outcompete Chthamalus barnacles and therefore restrict them to upper intertidal elevations. fundamental or realized niche?

Answer 1

Fundamental niche is the entire set of conditions under which a population or a species can survive and reproduce itself. Realized niche is the set of environmental conditions under which in reality the given population or species after interacting with other species survives. Specific enviromental conditions, Predation and competition are taken into account in realized niche. Accordingly:

a) No kangaroo species is able to inhabit northern Australia because the hot, dry conditions do not allow suitable plants to grow that kangaroos use as food - Realized niche.

b) Throughout their range, a species of tiger beetle prefers the same temperature - Fundamental niche.

c.) Some desert plants are only found in microhabitats with high soil moisture availability, because they avoid extreme high temperatures through evaporative cooling - Realized niche.

d.) Balanus barnacles outcompete Chthamalus barnacles and therefore restrict them to upper intertidal elevations - Realized niche.