Research Note: Garden-owner reported habitat heterogeneity predicts plant species richness in urban gardens

Amidst ongoing urbanization and increased research on urban greenspaces, the biodiversity level of these spaces is an important variable. Attaining biodiversity estimates by asking non-expert greenspace users to assess aspects of a greenspace has a number of advantages over expert assessments (costs, sample size etc.). This article discusses an approach to such a citizen-science assessment of plant species richness using reported garden habitat heterogeneity and visually assisted reported plant species richness. We compare expert-assessed plant species richness with garden owner-generated estimates in a sample of 83 gardens. We show it is possible to predict approx. 50% of variation in plant species richness in gardens using just two visual survey questions regarding habitat heterogeneity and plant species richness.