Marrja Boardwalk

The Marrja Botanical Boardwalk is a beautiful way to experience the ecotones of lowland rainforest within the Daintree. It is also one of the few places in the World Heritage Park that is handicap accessible.
The boardwalk takes you through lowland rainforest, licuala palm swamp, mangrove forest, and part of the river the mangroves enter into.

Licuala Palms

For the field trip we focused on the type of experience of the tourist and what impacts they were having on the environment/infrastructure, but also what impacts the environment & infrastructure was having on them.
The boardwalk's parking lot is small and the loop is meant to be walked in one direction. This minimizes the impacts on the infrastructure but also enhances the experience of the users by limiting the disturbance people have on each other. While taking you through the ecotones the path leads you away from the road and you can hear the forest. The birds, the rustling, the river, and the buzz of mosquitoes.
The licuala palms towering above our heads make us feel like we stepped back in a time before human existence. Perhaps dinosaurs could pop out from behind the bushes! This of course did not happen but the other group saw a cassowary with a chick. Definitely jealous- even though male cassowaries with chicks are potentially dangerous out of protection of their young.

Their pneumatophores are showing

Then there are the mangroves. It would seem there are two sections of mangroves. The mangroves closer to the swamp don't experience as extreme ups and downs in the water line as the ones that line the river (maybe we were there at low tide?). So these trees don't need to invest in a dramatic, high above ground root system. Instead they have small buttressed roots and millions of pneumatophores. Pneumatophores are specialized Arial roots that allow the mangroves to carry out gas exchange in spite of living in highly compact saline mud. Closer to the river the trunks of the mangroves begin higher above the ground, along with buttressing , the thick roots weave tangles that support and the trees and allow spaces for the pneumatophores to continue their gas exchange. The river is in an estuarine zone and has varying levels of salinity through out the day as the tides change. The salt is excluded from the mangroves and can be seen on some of the bark and can also be "pumped" into "sacrificial" leaves that the plant then sheds. This hyperacumulation in certain parts of the plant allows it to function in this relatively harsh environment. The mangroves use the movement of water to disperse their seeds and help to form the structure of their communities that also contain crabs, snails, and the occasional crocodile.

Roots and Mangrove Seedling

Ok, so while we didn't have to fill out a ROS assessment we were meant to be looking at the adequacy of the infrastructure. We found the concrete and wood would need to be replaced some time in the near future as wear, tear, and use caused it to rot or erode. To accommodate wheelchairs parts of the path could stand to be a little wider. The dead spaces under the boards was minimal, and designed holes in the fencing shows a good conscious effort to minimize the effects of liner barriers to wildlife movement. We concluded that no additions or enlarging of the car park should be undertaken in the interest of maintaining the peace and quiet of limited human traffic which makes this site so enjoyable.

Wonderful field trip, Thank you Dr. Joan!!