Abstract
South-western Australia is a global biodiversity hotspot that boasts the continent’s highest orchid diversity, yet is under increasing pressure from rapid urbanisation. Bushland remnants in the Perth metropolitan area host approximately 74 orchid species and the viability of many of these populations is threatened by ongoing urbanisation. Despite this, little is known about the influence that habitat condition and reserve characteristics have on pollination success, the ultimate measure of population viability. To address this, we investigated orchid pollination success along a habitat condition cline within urban reserves. The study utilised pollination success as a measure of population viability among orchid genera that represented the full spectrum of pollination syndromes, from sexual through to food deception. We found no significant correlation between overall habitat condition and pollination success (rs= 1.99, P= 0.313). Significant correlations with individual components comprising habitat condition such as litter (rs= 0.502, P= 0.005), shape index (rs= -0.487, P=0.009), and bareground (rs= -0.413, P= 0.026) were found, lending power to the use of predictive models. Our results show that pollination syndromes have variable responses to urbanisation which can be linked to their ecology. This study has conservation and management implications, providing insights into the influence of habitat condition components on population viability within urban reserves.