An award-winning Kiwi photo is coming under the environmental microscope because its idyllic mauve carpet is made up of lupins.

The flowers are pretty but they are running over New Zealand's wildlife, pushing out native birds that rely on the increasingly scarce native flora lupins are replacing.

The picture, taken by Richard Bloom, won the International Garden Photographer of the Year competition. Writing in the Guardian, conservationist Robbie Blackhall-Miles said "there is no doubt that it is an incredible photograph".

The photo, entered in the wildflower landscapes category, was praised to the hilt by impressed judges, but Blackhall-Miles suggested Bloom was aware of the potential fallout, when the photographer said of the snap: "On the way to Lake Tekapo on the South Island of New Zealand in early summer the landscape, already amazing, was scattered with drifts of naturalised lupins." Naturalised - or non-native.


Blackhall-Miles wondered if the judges knew about the problems lupins were causing in New Zealand when they handed out the award.

"The Russell lupin, Lupinus polyphyllus ... is such a mild-mannered and quintessential cottage garden plant here in the UK and a complete thug in New Zealand," he wrote.

"Colonising stream banks, just like in the picture, they are taking over a habitat so important for New Zealand's unique wildlife ...

"The lupins that look so beautiful are actually a non-native, invasive species. In New Zealand ... their detrimental impact is huge.

"But on the positive side, the pretty landscape lupins create attracts tourists ... and they do provide a good food source to some desirable creatures, such as the long tailed blue butterfly, another non-native."

Blackhall-Miles isn't sure if the photo should have won or not. "What I do know, though, is that the photograph, as a piece of art, did its job. It made me ... look deeper at the garden that is our planet."