Mangroves

Within the Daintree, there are three short forest walks that are managed by the Daintree National Park. The one that I enjoyed most was 'Marrdja', which - as the National Park leaflet puts it - offers "mud-free" viewing of mangroves.

Much of the coastline of the Daintree is either sandy beaches, or rocky terrain that drops steeply to the water's edge, ...

... but where silt and mud can build up - particularly at river mouths - mangrove forests develop. Usually mangrove habitat is muddy and tidal, but at Marrdja there is a raised boardwalk through the mangroves. I noticed that, as the walkway went further into the mangrove forest, there was heavy gauge wire netting - on the outside, so to stop something getting onto the walkway. There are estuarine crocodiles - the species that is a threat to humans - along the coast and in the lower reaches of rivers in northern Queensland.

This particular mangrove forest is bordered on one side by Noah Creek:

One of the problems that mangroves face is getting sufficient oxygen into their roots. Those species that live highest in the tidal range where the mud is periodically exposed have various structures on their roots - like the bumps on the roots of this mangrove - that allow them to 'breathe':

The species that live in deeper water, have stilt roots that prop them above the water level, and pores called lenticels through which they absorb air. The reflections of the stilt-rooted species were magical, if somewhat disorienting when cropped by the photographic framing: