A vegetation survey of Lot 110 Palm Road has identified one of the most important locations for the conservation of Fan Palm dominated tropical rainforest. The importance of the property was also confirmed by the presence of one of Australia’s rarest plants, one of seven plants on the property that are listed as Threatened species.

Fan Palm dominated tropical rainforest

Before we make a commitment to purchase a Daintree Rainforest property, we thoroughly assess its value to conservation. Consideration is given to biodiversity status (whether there is presence of endangered, threatened, or of concern vegetation), proximity to settled lots, canopy coverage, proximity to existing protected areas, and risk of future development. This assessment is undertaken by our conservation staff. As needed we also engage specialist ecologists.

A vegetation survey by ecologist Kristopher Kupsch was undertaken of Lot 110 (RP 738992) Fan Palm Road, Diwan, on the 30th of April 2021. His report follows.

The property of 8.098 hectares was found to have a well-developed intact assemblage of 199 species of native plants. This includes 7 Threatened species. Of particular importance was the occurrence of Isachne sharpii (no common name), which is a highly localised and Endangered. This small grass grows to 15cm tall and was found growing in water in a ponded situation. It was first identified in 2001 from specimens found less than 1km from Lot 110 and was only confirmed as a new species in 2010.

Fan Palm dominated tropical rainforest is classified as closed forest RE 7.3.4.  The Queensland government indicates “very little of this habitat (RE 7.3.4) remains” with an estimated 3,000 hectares prior to clearing and 1,000 hectares remaining in 2019. This Fan Palm dominated vegetation type solely occurs between Cardwell and Cape Tribulation and what remains, less than half is within reserves.

Lot 110 has two contrasting vegetation types.

The most prevalent vegetation type on Lot 110 is dominated by Fan Palms (Licuala ramsayi).

The Fan Palm vegetation on Lot 110 Palm Road is remnant with rainforest tree species interspersed and often emerging above the Palms. The occasional tree species include Brown Salwood (Acacia celsa), Northern Silky Oak (Cardwellia sublimis), Kuranda Quandong (Elaeocarpus bancroftii), Cassowary Plum (Cerbera floribunda), Golden Bouquet tree (Deplanchea tetraphylla). There are five species within the Pandanaceae (Pandanus family) within 3 genera and 8 species of Palms.  

The entire site is prone to permanently wet soil and seasonal flooding. This anaerobic state strongly determines plant species composition. Successful plant recruitment is strongly aligned with the chance ability of seedlings to grow on slightly elevated land that contains more Oxygen. Expanding roots furthermore bind silt and organic matter into larger mounds. Areas of better drainage possess a greater assemblage of species, akin to the rainforest of nearby Cow Bay.

Some species in this habitat have pneumatophores (i.e. Licuala Fan Palms and Pandanus) much alike Mangroves whilst the Swamp Macaranga and Climbing Pandanus has adventitious stilt roots for better support in wet soil. Fan Palms (Licuala ramsayi) dominate the site forming one of the most impressive examples of this species in existence. Fan Palms from which the road is named grow naturally on poorer metamorphic or granite derived soils. The Daintree lowlands has both these soils plus the influence of mud deposits from historical tidal deltas. Combined with the high rainfall and wet poorer nutrient soil favours the Fan Palms dominance.    

Kuranda Quandong emerging above the Fan Palms

The vegetation Regional Ecosystem (RE) mapping by The Department of Environment and Science, Queensland Herbarium is generally consistent with the site appraisal.

There are two vegetation types on Lot 110. Much of the vegetation is Regional Ecosystem 7.3.4 Mesophyll vine forest with Licuala ramsayi on poorly drained alluvial plains and alluvial areas of uplands.

The Queensland Herbarium vegetation mapping indicates a small area of the Lot has a mixed rainforest like vegetation however the mapping should reflect the dominance of Licuala Palms. A RE code of 7.3.4 is more appropriate, rather than 7.3.10.

RE 7.3.4 is listed as “Of Concern” under the Vegetation Management Act 1999.

The Queensland government indicates a pre-clearing amount of 3,000 ha existed with 1,000 ha hectares remaining in 2019.

The Queensland government specifically states that this vegetation type has “Special Values” being:

“Potential habitat for NCA listed species: Austromuellera trinervia, Dendrobium nindii, Endiandra cooperana, Freycinetia marginata, Phlegmariurus phlegmarioides”.

A second Regional Ecosystem 7.3.5a: Melaleuca quinquenervia open forest, woodland and shrubland. Lowlands of the very wet and wet rainfall zone, on poorly drained peaty humic gley soils where the water table is near or above the ground for most of the year. Palustrine wetland”, also occurs in the south-eastern portions of Lot 110.

In this habitat the canopy is mostly Paperbark (M. quinquenervia) and Blue Gum (Eucalyptus tereticornis). The Endangered listed Grass (Isachne sharpii) grows in the heavily sodden soil of the Ground layer and the Vulnerable Ant Plant (Myrmecodia beccarii) occurs in the canopies of the Paperbarks.

The Queensland government specifically states that this vegetation type has “Special Values” being:

“This regional ecosystem plays a critical role in the hydrological regime of the coastal plain”.

This property has also been identified as essential habitat for the Southern Cassowary Casuarius casuarius johnsonii. The Southern Cassowary is listed as endangered under Environment Protection and Biodiversity Conservation Act 1999 (Commonwealth) and ‘threatened’ by the Queensland Government (NC Act, 1992). Protection and conservation management of the habitat of these species is important for their survival in the wild.

Southern Cassowary in the Daintree Lowland Rainforest

Seven (7) species found on Lot 110 are listed on the Queensland Nature Conservation Act 1992 and One (1) of these species is also listed on the National Environment Protection and Biodiversity Conservation Act (EPBC) (Table 1).

Significant species found during survey: 

     1,     Beilschmiedia castrisinensis NCA 1992: Near Threatened

The China Camp Laurel only grows in the Daintree Rainforests between the Daintree River and the Bloomfield River where it is locally common. This species has large fruits the size of tennis balls that are only dispersed by the Southern Cassowary and thus a symbiotic relationship (+/+) has evolved in which they rely on each other, more so the tree in fact.

The species was occasionally found on Lot 110 as seedlings growing from Cassowary dispersal, no mature larger trees of this species were found.

     2,     Endiandra grayi NCA 1992: Vulnerable

Gray’s Walnut is a large growing Laurel tree only found between the Daintree River and Cape Tribulation in lowland rainforest below 40m asl. Its large seeds are dispersed solely by the Southern Cassowary. It has a large leaf with a distinctive glaucous whitish underside.

Gray’s Walnut

     3,     Endiandra microneura NCA 1992: Near Threatened

Noahs Walnut is commonly found on Lot 110 with a number of trees and many seedlings. It produces large yellow oblong shaped fruits are dispersed by the Southern Cassowary. This species is only found naturally within the Daintree rainforests predominately north of the Daintree River and south of Cape Tribulation. This tree is noticeable in the forest as it produces a vibrant display of limp red new leaves.

Noah's Walnut

     4,     Freycinetia percostata NCA 1992: Vulnerable

This Climbing Pandanus is abundant in many areas of the Daintree lowlands especially in wet swampy places, it is abundant on Lot 110 and in the Palm road region. It is restricted mainly to the Daintree and again on Cape York at Iron Range and overseas in Papua New Guinea. This climbing grass-like plant possesses unique leaves that trap water and thus provide habitat for invertebrates and frogs. These microhabitats are termed Phytotelms and add to the vertical diversity of a rainforest thus providing niches in the canopy for various arboreal animals which in turn pollinate the flowers and disperse the fruits of this plant.

Climbing Pandanus

     5,     Isachne sharpii NCA 1992: Endangered

The highly localised and Endangered grass was identified from open woodland paperbark habitat on Lot 110. This small grass grows to 15cm tall and was found growing in water in a ponded situation. This grass was first identified in 2001 from specimens found less than 1km from Lot 110. Originally named Isachne sp. Cape Tribulation (R.L.Jago 4560) and placed as a new species in 2010.

The highly localised and Endangered grass Isachne sharpii

     6,     Myrmecodia beccarii EPBC and NCA 1992: Vulnerable

The Vulnerable epiphytic Ant Plant (Myrmecodia beccarii) was identified within the canopy of Paperbarks in the open woodland habitat of Lot 110.

Myrmecodia beccarii, ant-house plant, is an epiphytic plant on Melaleuca trees and others with spongy bark in the wetlands and mangroves of tropical north Queensland, Australia from Cooktown to Mission Beach. The prickly, swollen stems develop natural hollows which are invaded by the golden ant (Iridomyrmex cordatus) in a symbiotic arrangement. The ants patrol the plant, removing leaf-eaters, while their excreta is absorbed by the plant for nutrition. 

The flowers are white and tubular, to 10 mm, and the fruit is white/translucent containing a single seed. These seeds are transported to other trees by the mistletoebird (Dicaeum hirundinaceum).

The Apollo jewel butterfly (Hypochrysops apollo apollo) lays its eggs on the plant, and because they smell like ant's eggs, the ants carry the eggs inside the plant, where they develop to the butterfly stage. Hypochrysops is a genus of "blues", butterflies in the family Lycaenidae, which is notorious for its myrmecophily. Accordingly, it is likely that the larvae that hatch from the eggs feed either on food begged from the ants, or on ant larvae, or possibly both. In either event, the butterfly finally emerges and flies off.

Ant Plant Myrmecodia beccarii - Photo by Daintree Life

     7,     Ryparosa kurrangii NCA 1992: Near Threatened

 The Daintree Ryparosa is a medium sized tree that occurs commonly throughout the Daintree in the remnant forests. It is rare on Lot 110 and grows commonly in rainforest with better soil drainage. This species relies on the Southern Cassowary for seed dispersal and produces flowers and fruits directly from its trunk, a feature known as cauliflory. This is a benefit to such plants in a leafy rainforest as it allows animals to easily pollinate the flowers as well as find and consume the fruit without the leaves obstructing.

This tree is only found in the Daintree lowlands with its closest relatives in New Guinea. There is evidence to suggest this tree has specialised symbiotic relationships with Ants. It produces food rewards from its leaves and branches that are presumably so the Ants protect the tree from leaf eating herbivorous insects and also help reduce leaf covering mosses, a tactic to preserve valuable leaves in a habitat which the limiting resource is light (energy) as this species is slow growing in these gloomy conditions.

Daintree Ryparosa

Other significant Daintree endemics that occur on Lot 157:

1. Cleistanthus myrianthus

This nondescript understorey tree is rare on Lot 110.

The Daintree Cleistanthus is a small tree only found between the Bloomfield and Daintree rivers in lowland rainforest and again overseas in Southeast Asia. Its seeds are dispersed by gravity which allows independence from an animal vector however the trade-off is limited dispersal from the parent tree and poses the question how the species also occurs many thousands of kilometres in Asia.

The species name Cleist-anthus refers to Cleist meaning closed and that the flower bud doesn’t entirely open and thus pollination occurs without the need of an insect/animal. Additionally, myri-anthus means many, derived from the word Myriad and Anthers referring to the male flowers which the tree produces in great numbers.

Kelvin Davies with Daintree Cleistanthus

     2.     Jagera madida

A handful of large specimens of Daintree Foambark are present on Lot 110.

This species only occurs in the lowland rainforests between Julatten – Bloomfield and has its closest relatives in SE Asia being quite distinct to that of the other Australian Foambark species in being slenderer, often a single trunk with a handful of branches. Until recently this tree was considered to be a species that also occurs in Java however closer analysis of its flowers, fruits and leaf characteristics has shown it is an Australian endemic restricted to the refugial areas of the Daintree where it is relatively common.

The species name madida refers to the trees fern-like foliage it possesses.

Daintree Foambark

     3.     Polyalthia xanthocarpa

The Cooper Creek Haplostichanthus (Polyalthia xanthocarpa) is common on Lot 110. This is an understorey shrub to 3m in height and is restricted to the rainforests ofthe Daintree lowlands, albeit found as far south as the Daintree village, the large majority of records comes from the vicinity of the Cow Bay – Cape Tribulation area. It is a recently described species formally recognised in 2007 as Haplostichanthus ramiflorus and then redescribed as Polyalthia xanthocarpa in 2012. It is common where it occurs but has a very restricted occurrence.

Kelvin Davies with Cooper Creek Haplostichanthus

     4.     Syzygium monospermum

The locally common Daintree Satinash is a unique tree that has Ants which inhabit its trunk. This species is only found in lowland rainforests between Cape Tribulation and Julatten. The tree provides food for the Endangered Southern Cassowary and owing to the size of its large white fruit that it produces straight from the trunk, few other animals other than possibly Fruit bats would disperse it.

Little is known of the reason why Ants colonise this trees trunk however it is known that the internal structure of the tree is a purpose-built network of tunnels which allow Ants to undertake their entire life cycle, what the tree benefits from this is little known and currently remains unstudied. This tree was only botanically named in 2003 and is relatively common on Lot 110.

Daintree Satinash

Other values of Lot 110:

The main value of Lot 110 are the impressive and dominant Fan Palms which captivate and delight an avid naturalist in awe of their beauty. On Lot 110 Fan Palms grow together with Hope’s Cycad (Lepidozamia hopei). Hopes Cycad (Lepidozamia hopei) occurs on Lot 110. This species of Cycad is the largest growing in the world and was once utilised by Aboriginal people as a food source. It has evolutionary links dating back some 200 million years and along with other ancient species form some of the reasons why the Wet Tropics World Heritage area has been afforded protection within the National Parks estate.

Hopes Cycad (self-portrait by Steven Nowakowski)

Weeds:

Lot 110 has minimal exotic weed occurrence with only 2 species noted.

Singapore daisy (Sphagneticola trilobata) occurs on edge of Palm road at the front of Lot 110.

Pond apple (Annona glabra) is present in the wetter Paperbark sections of Lot 110.

Exotic plant species are mostly associated with road edge disturbance however Pond Apple (Annona glabra) is present within the more illuminated undisturbed Paperbark forest. Pond Apple is able to colonise such niches by possessing buoyant water dispersed seeds plus by mammal and avian dispersal i.e. Feral Pigs and Cassowaries consume the large fleshy fruits.

Property owners immediately adjacent to Lot 110 have private gardens with exotic plants. There is the potential for Heliconia’s, Aroids and exotic Palms species colonising these forests.  

Recommendations:

1. Control and eradicate where possible exotic weeds (Table 1). Careful removal of Pond Apple (Annona glabra) to avoid disturbance and colonisation by other weeds.
2. Establish feral Pig management strategies on Lot 110