Double-ridge mounds improve tree establishment in saline seeps

The effectiveness of different mound types and mound heights for the establishment of Eucalyptus camaldulensis and E. largiflorens in the southwest of Western Australia was compared over two years. Double-ridge mounds (seedlings planted in a 0.5-0.9-m-wide trough between the ridges) gave the best survival (50%, averaged for both species, all mound heights and all study sites). In contrast, survival in standard mounds (0.1-m-wide trough) and single ridge mounds (no trough) was only 11% in each case. Survival tended to increase with increasing mound height. In the double-ridge mounds, the improvement was from 35% in 0.25-m-high mounds to 49-59% in 0.5-, 0.75- and 1.0-m-high mounds. There were no significant effects of mound type or mound height on tree height or crown volume index two years after planting.