Journal of the Royal Society of Western Australia, 86(1), March 2003 
Dampland Embankment Midslope 
Figure 4. Seasonal water relations patterns for four myrtaceous 
shrub species occurring at three positions differing in 
groundwater depth. Values are mean ± se. A: soil-to-leaf 
hydraulic conductance (K L ). K L values and se were calculated 
from the mean and se of transpiration, WP pd and WP^ data; B: 
range of xylem water potential (WP). Lower end of bar is mean 
WP pd/ and the upper end is mean WP md . 
winter and spring WP d data for A. fascicularis, H. 
angustifolium and £. paucijlora (embankment). 
For almost all species, soil-to-leaf hydraulic 
conductivity ( K L ) decreased by 65-95% from spring to 
summer, except for P. ellipticum where K L remained the 
same (Fig 4A). Summer K L was highest for the two 
dampland species (1.3-6.0 mmol nv 2 s* 1 MPa' 1 ) and lowest 
for both stands of £. pauciflora (< 0.2 mmol m* 2 s' 1 MPa 1 ), 
the latter due to low summer transpiration (Fig 3A) and 
a relatively small difference (< 0.5 MPa) between WP pd 
and WP md (Fig 4B). Overall, winter K L was lower than 
spring K l , with the exception of H. angustifolium. H. 
angustifolium had the highest winter K L (8.1 mmol m 2 s' 1 
MPa 1 ), reflecting a relatively large midday transpiration 
and a difference of only 0.03 MPa between WP pd and 
Soil moisture 
Gravimetric soil moisture contents decreased from 
spring to summer and increased from summer to winter 
at all sites, with winter data greater than for the previous 
spring at the embankment and midslope sites (Fig 5). Soil 
moisture content within the dampland site varied from 
8-20% during summer to 20-80% in winter. The soil 
moisture profiles at the midslope site were the driest of 
Figure 5. Gravimetric soil moisture profiles at the three 
topographical locations for spring 2000 (squares), summer 2001 
(circles) and winter 2001 (triangles). 
36 
