A new study has found that elephant-dependent tree species suffer catastrophic population declines when elephants are removed from the forests (Beaune et al., 2013). The study was conducted in Salonga NP in DRC, where forest elephants (Loxodonta cyclotis) are almost extinct. Here, the researchers explored how elephant-dispersed trees reproduce without elephants and how this affects their demography and spatial distribution.18 fruit-bearing trees that rely on forest elephants as their primary means of seed distribution were studied. Of those that were entirely elephant-dependent, they either did not recruit enough young for self replacement, or produced no young trees at all. There is no alternative partner for seed dispersal for the majority of the megafaunal trees which are actually elephant dependent. The authors conclude that the decline in this last cohort of elephant-dependent trees is likely to have been produced during elephant massacres in the last 30 years. The extirpation of forest elephants is likely to have serious consequences for forest composition in central Africa, probably with a new era for wind and ballistic dispersed trees.
Beaune D, Fruth B, Bollache L, Hohmann G, Bretagnolle F. (2013) Doom of the elephant-dependent trees in a Congo tropical forest. Forest Ecology and Management. 295: 109–117.