An experiment is about to get underway in the Daintree which will investigate how sustained dry periods may alter the fabric of the rainforest.

The lower than average rainfall we are experiencing this year may be a taste of things to come, and Dr Susan Laurance of JCU's School of Marine and Tropical Biology spoke to The Newsport about the current dry spell, and its effects on the rainforest ecosystem.

"We would expect trees to start shedding leaves because they can't get enough water to maintain all the leaves that they have," Dr Laurance said.

"There have certainly been some examples around the world where El Nino periods have resulted in a mass fruiting. I would suggest one of the reasons they think that happens is that because a lot of the mammal populations drop down, and the plants know it's a really good time to fruit because they're not going to get predated.

"I would expect it is a stressful time for wildlife....most of the fruiting has probably passed, because normally fruiting occurs prior to the wet season.

"If wildlife turns up in people's backyards, it's probably a good indication that there's not a lot of food out there," she said.

But according to Dr Laurance there are some species of trees that are able to withstand dry periods better than others.

"We do know there are some species that tend to be more drought resistant and often the really heavy, strong wood is very good...if you can imagine you've got all these straws that you're sucking up water to your leaves with. If you're sucking harder and there's less water available they get these embolisms, and if that happens you virtually lose your straw...the straw is dead and broken.

"The strong wooded trees tend to have very good support, structural support, so we know these kind of trees tend to do better."

Dr Laurance said James Cook University has received almost $900,000 in funding for an experiment to replicate dry conditions in an area of Daintree Rainforest 100 metre by 50 metre by building a roof cover to shield the undergrowth from as much rain as possible.

"What we've seen, this could be the future. I suspect we'll end up with something more monsoonal like Cape York. Generally around here we are quite dry for three to four months of the year, whereas up in Cape York, they experience much drier dry seasons.

"The wet seasons can still be wet, but if you have long dry seasons that can be really tough on trees.

"We'll try and remove the four millilitre and eight millilitre downpours, not the buckets of rain. We can study how much the sap flow changes and how much they photosynthesize, and we'll really be able to identify which species do well and which species don't," she said.

"What we'll understand is what species are likely to go extinct or really drop in their abundance, what plants will be the winners and what will be the losers?

"Then we need to find out what are the characteristics of the winners and losers. Are the losers the ones which produce the most fruit which is really important for lots of birds, or are the winners good fruit producers? We'll be able to look at the flow-on effects.

"What are the impacts of these groups of species on the function of the rainforest? That's how we'll work out what the long term impacts will be.

"There are some species at Cape Trib which are special to the Wet Tropics and they're only found at Cape Trib. If they're really high water-loving species we might see their long-term extinction from the world."

Dr Laurence said knowledge obtained from the experiment will form part of worldwide efforts to better understand climatic shifts and their impacts on tropical rainforests.

"There's been two other rain-exclusion experiments in the Eastern Amazon, and one that's been done in South-East Asia as well. We're all very aware of each other’s work, and expect to see similar findings."