A recent visit to Nobles Rocks uncovered some interesting biological clues that highlight how water levels have changed in the area just upstream of the outlet drain (near where the restoration trial commenced earlier this year).
You see, some perennial species of wetland plants are very good at hanging on – sometimes decades after a change in hydrology has occurred. For plants like water ribbons (Triglochin procerum), winter rains or a saturated soil profile can be enough for the plant to spring to life in the hope that deeper water may one day return… People with wetlands on their property would be accustomed to seeing this plant pop up, even in a dry year when their swamp may not fully inundate.
Based on the biology of this aquatic species, when you see water ribbons now “high and dry” growing among terrestrial (dryland) plants, you know that the place you are looking at was not only a swamp in the past – but one that held water for long enough for this aquatic species to establish in the first place. Over recent years, we have witnessed the potential response of plants like water ribbons to recovering water levels at sites such at White Sands in Long Swamp, and just over the border at Pick Swamp.
If you take the time to look around, the biological clues to the past existence of deeper water in Long Swamp upstream of the Nobles Rocks outlet can certainly be found – for an example photo, see the image below.
While the first phase of the restoration trial at Long Swamp has initially had quite a subtle impact on water levels, the completion of the next phase of the trial (this coming summer), will enable us to better evaluate the aquatic habitat recovery potential of this important area of Long Swamp in winter and spring next year… so we have some interesting times ahead in 2015!