Mangrove floras of the southern continents. Part 1. The geographical origin of Indo-Pacific mangrove genera the development present status of the Australian mangroves

Abstract

The often-expressed opinion that most important mangrove genera originated in South East Asia is questioned and rejected. A broader Tethyan origin is proposed for the mangroves. The age and specific diversity of the Australian mangrove flora is discussed in relation to the wider problem of the development and dispersal of the whole Indo-Pacific mangrove flora. This is believed to have begun during late Cretaceous times and to have been profoundly influenced by the separation of the various parts of Gondwanaland. The floristically rich contemporary mangrove forests of Malesia are considered to be relict, and to provide refuges for several sensitive species that were once far more widespread. The view that mangroves first entered Australia from the north and thereafter dispersed around the continent from a centre in north-eastern Queensland is also rejected. Die mening wat dikwels uitgespreek word, dat die belangrikste mangliet-genera hulle oorsprong in Suidoos-Asië gehad het, word bevraagteken en verwerp. ’n Ruimer Tethiaanse oorsprong word vir die mangliete voorgestel. Die ouderdom en spesifieke diversiteit van die Australiese mangliet-flora word bespreek met betrekking tot die wyer probleem van die ontwikkeling en verspreiding van die hele Indo-Pasifiese mangliet-flora. Hierdie verspreiding het waarskynlik begin gedurende die laat Kryttydperk en Is grootliks beïnvloed deur die skeiding van die onderskeie komponente van Gondwanaland. Die floristies ryk manglietwoude van Maleisië word beskou as oorblyfsels en verskaf beskerming aan verskeie sensitiewe spesies wat vroeër meer wydverspreid was. Die opinie dat mangliete Australië van die noorde binnegedring het en daarna om die kontinent vanaf ’n punt in Noordoos-Queensland versprei het, word ook verwerp.