Re-creating More Natural Plant Arrangements Can Improve Seed Production in Revegetated Woodlands

The spatial arrangement of individual plants play a central role in how ecosystems function and influence processes such as growth, competition, pollination, seed dispersal, and water and nutrient cycling. Consequently, the spatial arrangement of plants within revegetated sites is likely to influence the functional outcomes of restoration plantings. There have been calls to base revegetation designs on natural plant arrangements; however this seldom occurs, and the outcomes of failing to do so are poorly understood. The aims of our research were to (1) describe and compare plant arrangements in remnant and revegetated woodlands, and (2) assess how planting arrangement influences the ecological processes occurring in the revegetated site, specifically seed production. We found that aggregation was common in the remnant community and nearest neighbour pairs were often conspecific. While, revegetated sites were generally more dispersed and had greater spatial admixture of species. In revegetated areas, aggregated trees, or those with a neighbouring Eucalyptus leucoxylon, produced more seeds per fruit than dispersed trees. Therefore, we recommend that mimicking natural plant community spatial arrangements, where aggregation is common and nearest neighbours are often conspecific, as a guide to planting design, is likely to increase seed production in projects seeking to revegetate woodlands.