Islands in the sky: Urban biodiversity enhancement in NZ on indigenous living roof landscapes
Authors: Davies, Renee ; Simcock, Robyn; Toft, Richard
ABSTRACT: This paper analyses the habitat opportunities provided by the new landscapes of living
roofs in the New Zealand (NZ) context. The paper identifies vegetative design considerations for future
potentials in urban biodiversity enhancement.
Lack of local information and experience has been a barrier to living roof development in NZ. In
response, the first corporate extensive living roof using only New Zealand indigenous plant species
was initiated and completed a-top the Waitakere City Council (WCC) building in winter 2006. Plant
species suitable for living roofs need to be low-growing and adapted to the special environmental
conditions. Sedums are the norm on overseas roofs. The aim for the Waitakere roof was to find native
alternatives. A range of indigenous plant species have and continue to be trialed on the roof and
Monitoring of this project since its completion has provided important data on the potential of
indigenous flora within living roofs and has confirmed that NZ indigenous plants can survive on an
extensive living roof but that some are more resilient to the conditions than others. The results have
established a range of considerations for successful use of NZ indigenous plants on living roofs, both
horticultural and aesthetic.
Insect abundance and diversity is also being quantified using methods suited to windy environments
and low-stature vegetation (a first for NZ living roofs), results showing that a range of native and exotic
insect species are making the living roof their home with a surprisingly diverse fauna.