The appearance of your revegetation site at 10, 25 or 50-100 years into the future is going to be strongly linked to the environmental conditions experienced – and the management actions undertaken over that period of time.
In terms of environmental conditions, you may have a singular bad drought, or a very long drought period, floods, storm events, fire or inadvertent stock invasions, or any combination of these or other disturbances that impact your revegetation.
Any or all of these disturbances – and the timing of them in the timeline of your revegetation – can drastically influence the outcome and habitat quality of your site into the future.
These potential impacts will have an strong influence on the mortality of the plants or direct seeding that has been conducted on your property. For instance, a lower survival rate of your tree species will leave many open spaces in your revegetation site, while a high survival rate will lead to potentially a dense/closed canopy which restricts the direct sunlight at ground level and increases competition for plant resources, resulting in difficulty for understorey plants to establish and survive.
Notwithstanding any of these potential disturbances or combination of them, overall average environmental conditions and a reasonable survival rate across the period, and minimal management interventions, is most likely to result in:
At 10 years:
- The planted tree canopy will be establishing, and may be between 5-10 m in height;
- If there were no mature trees on the site at planting, then the planting is of trees and shrubs all of the same age, with no trees with tree hollows for fauna, which is a simple vegetation structure. If there were some embedded mature trees, these trees will still be providing hollows for fauna;
- Depending on whether planting occurred into a site dominated by exotic ground layer plants or whether some native species were found at ground level, it is likely that the ground layer will be dominated still by exotic species, albeit at a lower cover than at planting because of the impact of competition of light and soil resources provide by the emerging trees and shrubs. If there were native species present at planting, these will now be more abundant;
- The emerging canopy will not have yet started contributing significantly to a developing leaf litter layer, there will be little fallen wood on the ground, and there will be few if any standing dead trees;
At 25 years:
- The planted tree canopy will be more mature and still growing, and may be between 15-20 m in height;
- If there were no mature trees on the site at planting, then the planting is of trees and shrubs all of the same age, with no trees with tree hollows for fauna, which is still a simple vegetation structure. There may also have been some limited natural regeneration of planted tree and shrubs species in canopy gaps. This change represents an increase in the complexity of the vegetation structure. If there were some embedded mature trees, these trees will still be providing hollows for fauna;
- Depending on whether planting occurred into a site dominated by exotic ground layer plants or whether some native species were found at ground level, it is likely that the ground layer will be dominated still by exotic species, however, probably at a decreasing cover than at planting because of the impact of competition of light and soil resources provide by the emerging trees and shrubs. If there were native species present at planting, these will now be more abundant and may be dominating at ground level;
- The tree canopy will have started contributing significantly to a developing leaf litter layer, there will be some fallen wood on the ground from branchfall and treefall, and there will be some standing dead trees based on some normal planted tree mortality and with supressed individuals with adjacent tree competition;
At 50-100 years:
- The planted tree canopy will be more mature and still growing with a more closed canopy, and may be between 10-15 m in height;
- If there were no mature trees on the site at planting, then the planting, while still of trees and shrubs all of the same age, will now have some trees where tree hollows for fauna have formed in some individuals due to tree damage. There may also have been considerable natural regeneration of planted tree and shrubs species in canopy gaps. This change represents a further increase in the complexity of the vegetation structure. If there were some embedded mature trees, these trees will still be providing hollows for fauna;
- Depending on whether planting occurred into a site dominated by exotic ground layer plants or whether some native species were found at ground level, it is likely that the ground layer will be dominated still by exotic species, however, probably at a decreasing cover than at planting because of the impact of competition of light and soil resources provide by the emerging trees and shrubs. If there were native species present at planting, these will now be more abundant and may be dominating at ground level;
- The tree canopy will have started contributing further to a now well-developed leaf litter layer, there will be significant fallen wood on the ground from branchfall and treefall, and there will be more standing dead trees based on some tree mortality and with supressed individuals with adjacent tree competition.
The associated diagram provides a series of potential pathways for BushBank Projects assuming on going management actions and minimal environmental disturbance.