1 Fes., 1902.] QUEENSLAND AGRICULTURAL JOURNAL. 123 
Forestry 
IN CONNECTION WITH THE SAND DUNES OF QUEENSLAND. 
By A.J.B. 
ANY parts of the coast of 
Queensland are remarkable for 
the sand dunes which, in some 
localities, attain considerable 
elevation and gradually work 
their way inland. Wherever 
the natural coast timber, 
whether mangrove or cypress 
pine, has been destroyed, there 
the sea and the winds combine 
to form banks of sand which 
shift at every occurrence of a 
storm. From the Tweed River 
on the Southern border to 
Southport, and beyond Bris- 
bane at Caloundra, the same 
thing may be observed. Stradbroke Island, which forms, with Moreton Island, 
the sheet of protected water called Moreton Bay, is practically an immense dune, 
40 miles long by 64 miles broad, with an average width of 3 miles, the maximum 
height being 729 feet. This island is protected by a dense growth of scrub 
timber, but the northern and southern extremities are periodically washed 
away, and re-made on the occurrence of strong south-easterly winds. On the 
southern coast at Swan Bay to the south of Canaipa Passage, the sea, during 
a storm, broke through the great dune at a place formerly known to boating- 
men as Jumpin-pin, and which forms the eastern shore of the Bay, burst 
through the dune and made a very extensive opening, which daily widens 
by the washing away of the sand. At present the opening is nearly 14 miles 
wide. The same thing occurred at Mackay, in North Queensland. To the 
north of Townsville the coast dunes are extensive, but the natural growth 
of timber prevents them from shifting inland. As before stated, where the 
timber has been removed, the sand accumulates and encroaches upon the 
land. This is greatly in evidence at Southport, where the dune is piled high 
above the main roadway of the township. Inland the shifting sands are a source 
of great trouble to the residents. A jaree portion of the township is built on 
a second dune, and some again on a third. F 
The third dune, and in many places the second, is covered with a dense 
growth of timber which has sprung up owing to the protection afforded by the 
littoral dune. But thé very tact of the timber growth, and especially of the 
luxuriant undergrowth, has led to the destruction of large areas. Were there 
none of this undergrowth the large trees would be safe from destruction, 
because with plenty of clear space the easterly winds which, in this district, blow 
the sand into hills wherever the slightest obstruction in the shape of marrem- 
grass (Psamma arenaria) or the trailing Ipomea (Pes-caprae) occurs, here meets 
with no obstruction, consequently no dune is formed and the trees are safe. 
Wherever there is any undergrowth a dune will form, and it will continually grow 
higher and move further inland as the easterly gales drive the sand from its 
summit against the obstruction. Thus the sand may be seen rolling down like 
a river from the land side of the dune, slowly but surely engulfing the timber. 
This is clearly shown in the accompanying photographs. In the first may be 
seen the forest in process of destruction. he undergrowth has all been buried, 
and the trees, which are nearly all dead, are engulfed to a depth of from 15 to 
20 feet. The second picture shows how ee trees have been buried, killed, 
and have decayed beneath the sand, and finally have been uncovered only to go 
through the same process again. 
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