A friendly exotic - Chinaberry [苦楝 - 友善的外來客]

(Original articles written for the Newsletter of Hong Kong Gardening Society)

A friendly exotic - Chinaberry

The cold day came a little bit earlier this year.  After a period of sudden temperature drop, many deciduous trees had their colour changed.  While people usually chase for red leaves along hiking trail at Tai Lam Country Park, some other trees have their own way of changing – for example to golden yellow.

A mature Melia azedarach at Pat Heung

Chinaberry 苦楝 (Melia azedarach; MELIACEAE) is one of these players.  Despites its name that might imply, Chinaberry is not native to China or Hong Kong.  The tree is believed to be indigenous to South-east Asia and north Australia.  It is not clear whether the tree was consciously introduced, but their current wide-spread distribution in Hong Kong is obviously a result of successful adaptation.  In fact, arborists usually regard the tree as a naturalized species – a status that an exotic species can not only complete its life-cycle successfully in a new location, but also blend well with the ecosystem of the new location.

Fruit if Melia azedarach and its golden leaves as backdrop

Chinaberry is a very popular foraging site for local insects, fruit bats or birds.  In addition to a good source of nectar for bees, its small freshy drupes in the size of just ~1 cm is also one of the most attractive fruits to birds in the urban and suburban habitats, where the trees are usually found.  Frugivores like Chinese Bulbul, Chested Bulbul and different kinds of Starlings are common visitors on the trees especially during fruiting time and it appears that their beaks just fit the fruit size.  It is usually noisy above the crown when these birds are having their parties during sunset.

Myna's party on clusters of Chinaberry's fruit

Being successful in self-seedings as well as compatible to the local wildlife is by chance somehow.  There are in fact much more other cases that exotic species either do not mix well in the local environment, or even creating serious ecological problem.  If proved beneficial, a naturalized species may be an alterative choice to natives to improve our garden’ eco-friendliness.