Plant food

From Roderick Bieleski Your article on the faeces-trapping plant Nepenthes (1 February, p 43) was fascinating, but I have a quibble. When I visited the padang of Bako National Park in Borneo some years ago, I saw vegetation rich in four different types of insectivorous plants (Nepenthes, Drosera, myrmecophytes, Utricularia) growing on the sandy soil. But rather than a vegetation driven by nitrogen scarcity, what I saw when I looked out over the Kerangas forest was a place dominated by phosphorus deficiency.  While plants have worked out at least three different strategies for nitrogen-fixing symbioses, there is no comparable work-around for phosphorus. All of the behaviour of insectivorous plants fits a need to acquire phosphorus and a way of doing so just as much as it does for nitrogen. Maybe one day someone will take a look, and I bet that phosphorus will be found to be the key to plant carnivory, with nitrogen nutrition just a secondary player. Stanley Point, Auckland,  New Zealand