Relationship between Lakes and Meadows.

Between lakes, swamps, bogs, and meadows there is. a close connection. Sedges, raupo, rushes, and rush-like plants growing in the shallow water near the margin, of a small lake may in time, through their decay, turn that part into dry ground, and advance farther and farther until a water-surface is no longer visible, the whole having become a raupo or phormium swamp. From this, the transition to meadow land is, in many cases, only a matter of time.

The blocking of watercourses with aquatic plants can soon convert a meadow into a swamp. Even on shingly river-beds, swamps at various stages of growth may be observed, and toetoe grass, palmlilies, and phormium break the monotony of the scene.

Sinking of the land may bring about great changes in the plant societies, and remains of plant-life in bogs can teach much as to recent changes in the land-surface.

In the swamps in the neighbourhood of Christchurch large numbers of fallen trees are found, the remains evidently of a large coastal forest, which must have been replaced by swamp during a sinking of the land. So, too, on that narrow peninsula to the far north of Auckland is much kauri-gum to be met with in the bogs, a sure sign that the land stood considerably higher at the time it was occupied by the kauri forest, since that plant is most rare in swamps.