the accumulation helps. 



Steers: You showed slides of New Zealand in which the pans were 



rather indistinct. Why is that? Why is it that certain marshes 

 have well -developed pans and others do not? 



Chapman: Well, I think the reason there is apparently the Salicornia is 



able to colonize rather rapidly so that you do not get any of 

 what you may call primary pans where the area was left bare 

 in the original colonization, and then secondly the creeks are 

 remarkably infrequent in the New Zealand marshes as 1 

 pointed out yesterday and therefore you do not get the ends of 

 the creeks being cut off. 



Steers: 



Well then why are creeks so rare ? That is what I am trying 

 to get at. 



Chapman: Well, that, 1 think, is something that the physiographers should 



a nswer rather than the poor botanist. It is probably tied up 

 with the geology of the area, but as a matter of observation I 

 ■ do know that the creeks are remarkably sparse, and it is pe- 

 culiar because it has upset the whole drainage relationships of 

 the area and it has affected the growth certainly around Auck- 

 land of the mangrove species. There are some quite spectac- 

 ular differences between mangroves growing along the creek 

 e dge and away from the creek. The water movements are 

 quite spectacularly different away from the creek than they 

 are adjacent, even more spectacular than they are in the 

 British salt marshes where it is being investigated, and on the 

 American salt marshes around Boston where it is being inves- 

 tigated. 



57 



