46 



The Sea Shore and its Plant fife. 



By E. J. Salisbury, D.Sc, F.L.S. Head October 8th, 1914. 



The great French philosopher Bergpen has probably clone more 

 than any other writer to emphasise the constant and never ceasing 

 change that often underlies superficial stability, and perhaps 

 nowhere than in the realm of nature are we so apt to mistake for 

 permanent condition the successive phases of progress or retro- 

 gression. In dealing with Coastal Vegetation we cannot divorce 

 our study of the plants themselves from a consideration of the 

 habitat in which they live. For the habit, mode of growth, life- 

 history, and internal structure of the various species are most 

 intimately related to the diverse conditions of their environment. 

 It is more especially the ever changing character of the Sea Coast 

 and the relation which its denizens bear to this special condition 

 that I wish to lay stress upon. The Koyal Commission on Coast 

 Erosion did much towards focussing public attention upon our' 

 coastal gains and losses. But even now, except in a few striking 

 instances where the sea annually advances to an appreciable extent, 

 the fact is overlooked that along our whole seaboard, encroachment 

 either by sea or land is constantly proceeding. At one point the 

 change is secular, at another rapid, but everywhere the same great 

 battle ; and it is always where the fight is fiercest that vegetation 

 most prominently plays it part. 



It is the plants that are the most important factors in reclamation, 

 and though w'e so often think of coast protection in terms of groynes 

 and breakwaters, these imposing and expensive structures are often 

 far less effective than the plastic barrier set up by the vegetation. 



It is probably not too much to say that the time will come when 

 we shall combat the natural forces of erosion by a carefully directed 

 utilization of the plants which, having found their home and 

 flourishing under these specialized conditions, have become 

 peculiarly fitted for this warfare in which they are constantly 

 engaged. 



The following is a brief resume of the subject matter of the 

 lecture. 



The Sand Dune. — The chief conditions of this type of habitat are: 

 the mobility of the soil ; the large size of the soil particles, 

 involving lack of retentiveness and capillarity, and deficiency of 

 humus. The adverse factors encountered by the vegetation are 



