(a(i))[1]
State the term for all organisms of the same species living in a defined area at a particular time.
(a(ii))[1]
State the term for how all living organisms interact with each other and with the non-living environment in a self-contained place.
(a(iii))[1]
State the term for the change that turns nitrate ions in soil into nitrogen gas in the atmosphere.
(b(i))[1]
Name the trophic level of the Pied Oystercatchers.
(b(ii))[2]
Explain why the energy taken in by the crabs is not all available to the Pied Oystercatchers.
(c)[4]
The crabs in Fig. 6.1 also feed on mangrove leaves that have fallen onto the ground. Leaves that are not eaten provide a source of nitrogen for the mangrove trees. Explain how nitrogen from compounds in the dead leaves is made available to the growing plants.