Patterns and drivers of structure, diversity, and composition in species-rich shrublands restored after mining

摘要

Long-term studies of vegetation recovery following post-mining restoration in low-productivity, high-stress areas are limited, but essential for understanding underlying ecological processes and evaluating management practices. This study's goal was to describe temporal patterns of recovery (up to 37 years) in vegetation structure, floristic diversity, and composition following post-mining restoration at two sites, and identify potential drivers of restoration outcomes, in the nutrient-poor, seasonally dry, species-rich, fire-prone kwongan vegetation of southwest Western Australia. Vegetation development is progressing and restoration measures are within range of native reference values, but there is large variation in both patterns observed and restoration outcomes. Several patterns described share similarities with post-fire recovery of kwongan, and post-disturbance recovery of other low-productivity, high-stress, fire-prone systems. However, differences in some patterns between sites indicate differences in the underlying mechanisms of recovery. Many management and environmental variables emerge as significant drivers of restoration outcomes but age, fire, and the planting of seedlings account for the largest amount of variation. Adaptive management at both sites appears to be facilitating improved restoration outcomes over time. Using a combination of space-for-time, plot level, and linear mixed effects modeling perspectives to examine patterns provides greater insights into restoration recovery than a chronosequence perspective alone. This study will inform restoration practices and outcomes not only in kwongan but in other comparable systems also.