Tourism can affect the swamp water, if traveled on a boat, with all the oil and stuff that is needed to get the boat running, and over hunting, can slowly kill all the crocodiles that live there affecting the crocodile population! <span />
1. Naked Seeds, Gymnosperm means 'naked seed' and these were the earliest trees to evolve. They do not produce flowers and have seeds which are directly exposed to the air for wind pollination. Pine cones are one example. For ease you might think of the gymnosperms as conifers, such as yew and Scots pine.