SCLEROPHYLL FORESTS AND WOODLANDS

OF THE WET TROPICS BIOREGION CLARKE © CAMPBELL Syncarpia forests and woodlands (vegetation codes 60a-60g)

Syncarpia glomulifera can range from an extremely tall Facts and figures forest tree to a stunted shrub as a direct responds to its surrounding environmental conditions. Very few species Vegetation alliances demonstrate such an ability to respond to environmental Syncarpia glomulifera forests and controlling factors with such plasticity in growth form. woodlands Variations in height are typically a response to edaphic Current extent in the controls although factors including climate and exposure bioregion 38,125ha also have a significant influence. Syncarpia dominated Area protected 29,466ha (77%) vegetation associations are widespread across the bioregion, being found from the wet coastal lowlands to the dry western uplands. Geography Association 60b represents a well developed lowland This is a widespread formation which varies structurally variant, typically found on alluvial flats to the south of across a range of topographic and climatic zones Cardwell with scattered occurrences in the Kuranda area. throughout the bioregion. Well developed tall open forest Observations suggest that Syncarpia glomulifera favours variants are found in dry to wet upland situations from better drained alluvial situations, being displaced by Tinaroo to Rollingstone and in lowland situations on the Eucalyptus pellita in swampier localities. coastal plain between Cardwell and Ingham. Lower stature Association 60c (Syncarpia glomulifera and Melaleuca woodland and open forest associations are widespread quinquenervia) has a restricted distribution and is only being governed to a large extent by soil development, for found in extremely wet, infertile conditions due to a example, associations 60d, 60e and 60f are found on steep combination of groundwater seepage and highly infertile escarpments with minimal soil development. Major quartzite geology. occurrences are mapped in the Ingham area (Mt Gardiner), Hinchinbrook Island and adjacent mainland ranges and on In comparison with 60a, the lower stature of associations the Rollingstone, Kirrama and Gordonvale map sheets. 60d, 60e and 60f is invariably the result of shallower soils Association 60c is only found on the Thornton Peak map and greater wind exposure. These variants can typically be sheet as a result of unique geological and hydrological defined by their association with various Allocasuarina spp. influences. Association 60e, which is found in wetter locations, forms an association with Allocasuarina torulosa. In areas of low Shrubland variants are restricted to the drier western soil fertility, poor soil development and/or in drier areas, upland portions of the bioregion on granites and rhyolites Syncarpia glomulifera is often found in association with from Mt Spurgeon in the North to Paluma in the south. Allocasuarina littoralis (60e). Association 60f typically occurs on sites with rudimentary soil development (rudosols) and generally in dry western portions of the bioregion with only scattered occurrences on the coastal escarpment. The association is typically dominated by Syncarpia glomulifera with various Eucalyptus spp. present as minor components. Syncarpia glomulifera shrubland associations are invariably found on the drier western margins of the bioregion where they are confined to upland areas on shallow soils derived from granites and rhyolites. Association 60g represents a complex floristic and structural association, although Syncarpia glomulifera is universally present in shrub form (generally below 3m in height). Internal variations are generally dependant on fire history and soil depth with families of Ericaceae, Proteaceae, Xanthorrhoeaceae and Myrtaceae commonly well represented in the floristic mix. © CAMPBELL CLARKE © CAMPBELL CLARKE © CAMPBELL

Impacts and changes Threatening processes Major changes are generally associated with alteration of • Altered fire regimes and colonisation by fire retardant the structure and composition of sub-canopy and shrub rainforest species. layers due to changes in fire frequency and intensity, as well as alteration to structural and floristic integrity of canopy layers as a result of previous heavy logging Tenure regimes. Well represented in conservation estate including These effects are most apparent within the tall open forest Herberton Range NP, Mount Lewis NP, Danbulla NP, association 60a where changes to fire regimes has allowed Dinden NP, Fitzroy Island NP, Gadgarra FR, Gillies rainforest species to colonise the lower structural layers of Highway FR, Girringun NP, Goold Island NP, Grey Peaks wet sclerophyll forests. Heavy logging of these NP, Hinchinbrook Island NP, Kirrama NP, communities has undoubtedly influenced floristic Koombooloomba NP, Little Mulgrave NP, Malbon composition and it is likely that a canopy dominance of Thompson FR, Mount Hypipamee NP, Mount Spurgeon NP, Syncarpia glomulifera in some localities is an artefact of Mount Windsor NP, Girramay NP, Paluma Range NP, Tully the selective logging of the more desirable Eucalyptus Falls NP, Tully Gorge NP and Wooroonooran NP. resinifera and Eucalyptus grandis canopy species. The predominantly edaphic control on development of associations with lower stature places a limit on the Management considerations degree to which rainforest species can colonise the lower • Appropriate fire management and prescribed burning is structural layers of these communities. A thickening of important for the maintenance and dynamics of this sub-canopy and shrub layers can however be related to a extensive formation. lack of regular burning. The relative intolerance of Syncarpia glomulifera to extremely hot fires has undoubtedly contributed to floristic and structural changes within association 60e in areas subject to wildfires. The net result of wildfires on these communities may include the gradual removal of Syncarpia glomulifera from upper structural layers, suppression of the capacity for recruitment of Syncarpia glomulifera in shrub layers, and an increasing dominance of Allocasuarina littoralis throughout all structural layers.

Key values • Important arboreal mammal habitat for species including the yellow-bellied glider (Petaurus australis) • Habitat for the endangered northern bettong (Bettongia tropica) • Habitat for a number of restricted plant species including Bertya polystigma, Pityrodia salviifolia, Pomaderris argyrophylla, Dodonaea uncinata, Phebalium longifolium, Persoonia tropica, Diuris oporina, Eucalyptus lockyeri, Homoranthus porteri and Prostanthera clotteniana.

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