Small run-off plot at Lak e Augusta.

:�o

490

S�l' (�c tJre run-oFf plot : Loc o..tion: DiI1'811:'>.i" Dn�J : }"1.8C OI'·::inC 1 :8cbG'1i�:r,� : Control :

29 .7rn

_x

_16.5m

(90 1

_x

50 1 ) .

depth over tbr: Dla L . r:ecoyvEn:; vir perl record8

Rnd '2 l:e8k chart . •

gc.u:q:o ',Ii t h ide,1.tj cal mm recorderG.

Cons tr:.lC t i o n : Plot c')vered Hith bloc�: p::>lyc thylene Pt" �'3\;inc

consis tinG

of

2,

9. ::l.

( 30 1 )

::;r:ect,s 1,<,!el�f'd

tOf,e ther

by

he_{at scalinG wd 8.ttachcd to timbsX'}

round the edge [>.3 Hi th the

sr..�'ller 56

8'1 . m .

pl o t fi . Site selected f o r absence of I'r:)j e c tin� rocks ·'3nd slo';:'8 _. drain5.np' � to or�c corner. 3ite

preprrej for p .1 2 8tic b:r removing sLic:-:s, st.on8s and pro tl1ding bushcs, end by digzln;:; d:r:J.ini:"�r:G

1 !)

g!'�tI:e

',-lire frn..rre'.Jori: eons

true ted in n .'�ri 1

fDr e.tt.".chr;;ent of

bu::hcs

DB shol.m

in

p].7" l".e

1 8

Brrmchc:J stoo.:J on Dlastic and tied to f:!:"p::-p',lorkJ

l "' �v� n·� ' - .' ..

6

.' . " 'j- ' r::J'Jn:l. .' j- ' .,r;.s

This e:zs2 ri.mcnt

:'ei 10d

rJ.1.1S to ::> cCf'lb1nrcLion of

Loe!'. tiO!i. :

,. . .

_.8 C r: �_nJ.�.-:: Control : IJ, • time c:-:art.

dolcrit.e r:'c:-:. ccverj n:: ::;aver:'>.} hect!:'.re� th.nt

had been cx.:Jo�ed durj nz H . E . C . o!",.. ra tj on::;

on

Lr>7.e

AUS1�:ta

dam. F:>lJ s of

concrrc: te, ::

cr:. in

find drn:i.n:':�e '·::)s

vie. 1 3 !':!ctl'CS

flf 7 . 6

_e.'l:.

1 0

C!� .• dc�? Ste�l p::st,::; '

. .'1. th 1 ft

re!nf(lrdnr:

�teel , .�, .-1"".1 (

-

'

-

'

--

'.'

Up.d to t,f�0 !Jor.ts.

(SE'C

:;>

l

a

t

e

1 9

) .

, • p <' _{,. "}

Construc tion :

(

C o n e d .

)

O!,C

rn ti 0:1 :

, f " ' t " 'ouc" e " o

f!'eezlnc 0 H,-' uBI' ' . .:J. ,un '-'� .

Of'C?TI't.ion cor. tinu�d un'."(>l'

Clctoi::er 1973.

orisillC m r-.... • O,!' belo··, �ro:.t."'!.d l,.,,·: .... � .

18.rz:e numbp..!"� of indi.-l:i:L.l.a:' c')ntqincrs .

P!"O'lC

used as

an

imper_viDus ground CO"J"er. ocicuJ.f.lris lr.;:av�s are

needle shaped alld E:xtrelilely xel'omorphic, \.Ji tll the result tha t leaves change colour and sl1af-€ very little even after long periods of detach­ ment from a root system, especially in H_inter months when rains are an almost daily occurance . The Same is true to a lesser extent Hith the eucalyp ts, \Jl1icb retain tneir leaf snape and coloJr rigtLt throuGh the

Hinter Hb.en bra!lClleS are cut from a tre e . Althou_{g l}l _{considered wde sirat}

the practice of detllchI!lent of bra

n

ches from their roots e�!I�bled sirr,ulatl?

natural conditions for as long as

6

months without undue l oss of leaves,

and Hithout the complication of transpirational loss that ",ould b.ave re­

sulted from usinz living bushes in pots. Direct uptake o f water by

leaves was considered negligible

for

all tri_als.

Folythene shee ting used t o ensure cDmplete impe rmeability o f the ground was of

.006

gauge

Md 9

m.

(30 1 )

wide. This prove

d

satisfac tory

in the smaller

56

sq. metre plo ts, but Has plagued by troubles in the large plot

(490

sq. metres) at PinG Lake� This Has partly caused by

the lateness of installation o� the plot (October

1 972)

and d�y weather in spring dried up several pools of water holding down the pplythene and wind was able to move the plas tic up and d oun wi th a flapping motion.

A

second difficulty \-las caused by tearing o f the plastic in a few stra-

tegic positions Hhere \oJater

drained

to the recording gauge . Rep_a

i

rin_g

tape recommended by the manufacturers of the polythene pro7ed unsatis­ factory in the extreme condi tions of the site a,'1d makeshift measur8S we:c",

only beginning to work when vandals tore the plastic into an irreparable

state. The result of this important trial at Pine Lake was ou:y approxi­ mately 1 month I s record du:-ing whicb time nothing of any significaJ1ce

c ould be detected from tb.e charts comparing rWl- off, rainfall, f'�nd small

In document Interactions between vegetation and water yield in Tasmanian highland catchment (Page 69-76)