By Evizel Seymour, Community Facilitator, Terrain NRM
Mabi Forest, also known as Complex Notophyll Vine Forest (or Type 5b), once covered the Atherton Tablelands area, north and west of Malanda, occurring only on fertile basalt (red) soils in areas where rainfall is between 1300 and 1600mm [see diagram 1]. Mabi forest now only exists in fragmented remnants with less than 2% surviving, hence classified as critically endangered. It was originally classified in the 1960’s, based on the structural characteristics of the Tolga Scrub.
These structural characteristics include:
- Many buttressed canopy trees up to 45m, with an uneven canopy
- A very well developed shrub layer one to three metres high
- Presence of scattered, often deciduous and semi-evergreen trees
- Tendency for heavy leaf fall in times of moisture stress
- Stem diameters are uneven
- Epiphytes and generally uncommon and orchids are rare.
Mabi is largely distinguished from other rainforest types by having a dense scrub layer resulting from the flora canopy being either deciduous or semi-deciduous. Key canopy species include candlenut, Black Bean, white cedar, red cedar; key sub-canopy species include lemon aspen and corduroy tamarind.
Due to widespread clearing of Mabi Forest 3 plant speciesare listed as ‘vulnerable to extinction’; the Pink Silk Oak, Atherton Sauropus and Atherton Turkey Bush;four plants species listed as ‘rare’, the pink leaf Haplostichanthus sp., Coorangooloo Quandong, Red Penda and Gray’s Cryptolepis.
Mabi Forest draws its name from the local aboriginal name for Lumholtz’s Tree-Kangaroo (mabi yidgin-ji or mapi Ndajon-j). Other rare or threatened Mabi Forest mammals include the Large-Eared Horseshoe Bat, the Diadem Leaf Nosed Bat and the Green Ringtail Possum. The Musky Rat-kangaroo is now locally extinct within Mabi Forest.
114 species of birds are known to reside, nest or forage in Mabi Forest. Twelve of the 13 bird species occurring only in the Wet Tropics region are found in Mabi Forest including the Tooth-billed Bowerbird, Victoria’s Riflebird, Atherton Scrubwren, Chowchilla and Lesser Sooty Owl. Many Mabi Forest birds play key roles in seed dispersal and pollination, as do the Spectacled and Little Red Flying-foxes which also use Mabi Forest.
Since European settlement, Mabi Forest has been extensively cleared and fragmented. The current extent of Mabi is 861.9ha, the largest fragment at 271ha [Curtain Figtree NP]; 73% of the remnants are under 5ha in size. These remnants suffer threats from feral and domestic animals, weeds, and the effects of isolation, with weeds an especially serious threat. Garden escapees such as Turbina and Madiera vines, Japanese Sunflower and Anzac Weed commonly choke forest patches.
Turbina vine has migrated from the Curtain Fig National Park region, downstream to Cairns. It has remained relativelyhiddenbut was quick to establish after cyclones Larry and Yasi battered the area. Where trees were blown down causing forest gaps, Turbina vine quickly established chocking the remaining trees.
A Mabi Action Group [QPWS, CSIRO, BCC, TRC, Terrain, Chorechillum and Yidinji] has been established to strategically plan and manage the incursions. A grant was obtained by Barron Catchment Care [BCC] to survey the area to determine the extent of Turbina on the Atherton Tablelands and along the Barron Riverwith follow up on-ground works.
QPWS – Queensland Parks and Wildlife Services
CSIRO – Commonwealth Scientific and Industrial Research Organisation
BCC – Barron Catchment Care
TRC – Tablelands Regional Council