Biodiversity (biological diversity) is the term used to describe the variety of species that exist in the natural environment and includes a variety of plants, animals and ecosystems (the interaction of these species) that make up the life of the Shire's natural environment. Biodiversity is important because it is essential for the provision of clean air and water, new crops, medicines and commercial products, basic life support systems, and importantly, the aesthetics of the Shire. The Australian State of the Environment Report states that loss of biodiversity is perhaps the most serious environmental problem and the major cause of biodiversity loss is clearing of habitat.
Johnstone Shire is located within the Wet Tropics Bioregion and forms part of the Innisfail Province. Many of the regional ecosystems in the province are considered endangered or of concern. These ecosystems are home to an array of fauna including mammals, birds, reptiles, frogs and fish.
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Source: Department of Natural Resources 2000
Native Vegetation
The vegetation communities in the Johnstone Shire form part of the Wet Tropics Bioregion. The bioregion is dominated by rugged rainforested mountains and the majority of the area is within the Wet Tropics World Heritage Area.
The Innisfail Province of the Wet Tropic Bioregion is characterised by: a quaternary alluvium geology; landforms including low beach ridges and swales, alluvial plains, channels, levees, lagoons and low hills; soil including alluvium, red earths, yellow earths, water saturated soils; & vegetation including rainforest, mangroves, coastal dune vegetation, paperbark forest, palm swamps and eucalypt woodlands.
Ecosystems of concern include Bulkuru Swamps, woodland vegetation on old dune ridges, lowland rainforest, and palm dominated rainforest.
Endangered ecosystems include rainforest on lowland beach sand, sedgeland and grass swamp land, palm swamp rainforest, swamp paperbark, riparian shrubland, and semi-deciduous rainforest.
Occurrence of Rare and Threatened Flora
The Shire is home to a variety of rare and threatened flora. The list of species is too large to include in this report however one of the most recognisable species is that of the Native Sugar Palm (Arenga australasica). This palm inhabits stoney creek beds on sandy or red soils in near-coastal rainforest. The palm is tall, clumping, feather-leaved and is usually dominated by 1 to 3 stems.
Fauna
Information on the occurrence of fauna specifically for the Johnstone Shire is not available and therefore information for the whole Wet Tropics Region has been used to give an indication of what may occur in the Shire. 566 species make up the terrestrial vertebrate fauna of the Wet Tropics Biogeographic Region and this represents 28% of the entire Australian terrestrial vertebrate fauna. Approximately 23 % of all species in the region are regarded as important species due to their rare or threatened ranking.
Occurrence of Rare and Threatened Fauna
The Johnstone Shire is home to many rare and threatened fauna and the most recognised species is the Cassowary. The Southern Cassowary is the largest and most spectacular bird found in the rainforests of the area.
Studies of cassowaries at Mission Beach now indicate that there are fewer than 50 adult birds within the 90 kmē surveyed. Cassowary management projects have been prepared to identify cassowary population densities, population distributions, population movements, feeding habitats, key food sites, areas of habitat reduction, areas of traffic hazard and land use.
The major threats to the cassowary include habitat clearing and damage, encroachment and intrusion of people and dogs, hand-feeding of birds, and road crossings.
