Background information and definitions
Planting shrubs in clusters may result in an alteration of microclimatic conditions which favour their survival and growth.
Supporting evidence from individual studies
A randomized, controlled study in 2000–2001 in a formerly mined karoo shrubland in Cape Province, South Africa (Blignaut & Milton 2005) found that planting shrub species in clumps led to an increase in their mortality. After one year the percentage of shrubs planted in clumps that died (39%) was higher than the percentage of shrubs planted on their own that died (25%). In 2000 adult shrubs of three species (Aridaria noctiflora, Drosanthemum deciduum, and Psilocaulon dinteri) were removed from a shrubland and translocated to a formerly mined area. Ninety-six clumps each consisting of three shrubs of different species were planted with one clump per 25 m2 plot, while 288 shrubs of the three species used were planted alone in each plot. Survival of plants was recorded in 2001.Study and other actions tested