During the test, the plants reached maximum growth during
the summer months, whilst temperatures and relative humidity
levels were high. Both species reached maximum height in 2012 at
194 cm for A. donax and 173 cm for C. alternifolius (Fig. 3). In 2013,
due to different microclimate conditions compared to 2012, the
plants did not grow at the same rate as the year before and average
monthly values were approx. 157 cm for giant reed and 140 for
umbrella sedge. If we look at growth rates for C. alternifolius
over the two years, the species grew in height by 0.73 cm/d
between May and July in 2012 but by 0.67 cm/d during the same
period in 2013. After the month of August, plant height remained
relatively constant until the end of the growth period. Average
culm/stem density during the two years was 21 culms/m2
for giant reed and 77 stems/m2
for the umbrella sedge