New Scientist 4 Feb 11;
MANGROVES may be the unlikely winners from Australia's recent floods, benefitting from the nutrient-rich sediment that was washed into their forests.
So says Catherine Lovelock of the University of Queensland in St Lucia, Australia, whose team was recording how mangroves in Exmouth Gulf, Western Australia, respond to artificial phosphorus and nitrogen fertilisation when cyclone Pancho hit the area in 2008.
Before the cyclone, the trees' stems grew by less than 25 centimetres per year. After the cyclone, however, some stems shot up by 65 centimetres per year, thanks to floodwaters washing in soils enriched with nutrients from agricultural products. The team's preliminary results were presented at last year's International Congress of Ecology in Brisbane.
Lovelock says sediment is already collecting in mangroves around Moreton bay, Queensland, following the recent floods and suggests that they, too, will experience a growth spurt.
Coastal water habitats are less likely to benefit, though. Michele Burford of Griffith University in Nathan, Australia, fears the sediment may stimulate algal growth in Moreton bay, which could lead to oxygen-starved dead zones similar to those seen in the Gulf of Mexico in the wake of last year's oil leak. "Already, the algae are growing faster," she says.
