Stephanie Law is a second year PhD student in the University’s Department of Earth, Ocean and Ecological Sciences, and is currently completing her second field trip to Borneo:
“Borneo is home to one of the oldest rainforests in the world and it is here I am fortunate to conduct the fieldwork for my PhD. For 3 months I am based in Maliau Basin Conservation Area, also known as ‘Sabah’s Lost World’ in recognition of its wilderness and the large areas still yet to be explored.
Maliau is characterized by a huge, circular basin of pristine forest drained by a single river, the Maliau river, and is bounded by an escarpment that reaches over 1,600 m above sea level. The large elevational gradient encompasses a range of forest types from lowland mixed dipterocarp forest where I work, to tropical heath forest.
I have travelled here to study ants that live in the canopy of tropical rainforests. Ants dominate invertebrate fauna in tropical rainforests, making up to 60% of arthropods found in the leaf litter on the ground and also in the canopy.
Ants fill varied ecological roles, as predators, as seed dispersers, herbivores and as mutualists, consequently they are expected to have large impacts on ecosystem processes. I am trying to determine to what extent ground ants influence the distribution of canopy ants and how ants affect ecosystem processes such as herbivory in the canopy and forest productivity.
To answer these questions I am working within experimental plots where ground ants have been suppressed. I have been spending months, both last year and this year, collecting samples of ants and other invertebrates from the canopy.
So how do you sample in the canopy of the tallest trees in the tropics? Well it all starts with a big shot, a huge catapult used to propel a fishing line over a fork at the top of the tree. Using this line climbing ropes are pulled up and anchored at one end to a second tree. Pulling heavy ropes up and down trees every day is definitely good for building arm strength! So with some very long ropes and specialized climbing gear I have been hauling myself up trees that frequently measure over 50 m tall to set traps, to beat vegetation and to collect leaf samples.
Working in the rainforest comes with challenges: heat, humidity and mosquitoes are the ones that immediately come to mind. Collecting data from the canopy of rainforests presents additional concerns, other than the height there is always the dread of climbing into a bees nest.
Yet rainforest research is extraordinary. I have been privileged to see gibbons swinging from adjacent trees whilst climbing, elephants that, despite their size, remain well hidden behind vegetation until you run into them and even a sunbear raiding my kitchen supplies. Most importantly though are the diverse ants that I now have in my samples.
Image: Polyrhachis ants are commonly found in the canopy. Notable by the long spines seen in the thorax and petiole.
All of these specimens will be brought back to the lab in Liverpool for identification. Along with the data I collected last year I hope to shed new light on the interactions between ants occupying different strata in the rainforest and how vital they are for the health of our rainforests.”
Image: Beating is used to collect all invertebrates. This 1 m x 1 m tray is pulled up into the canopy to collect invertebrates that fall when the branch is beaten with a long pole.