The many thousands of farms dams scattered across regional NSW have an important role to play in enhancing biodiversity when managed appropriately.
During a recent NSW Biodiversity Conservation Trust (BCT) webinar, Managing Farm Dams for Biodiversity, Australian National University and Sustainable Farms ecologist, Dave Smith, shared his research findings and discussed why enhancing farm dams for agricultural use can also benefit habitat and water for native species.
Dave said that while a dam’s initial and main purpose was to provide agricultural water storage, there was evidence that farm dams can act as artificial wetlands and be a critical refuge for native flora and fauna.
As part of its research the team at Sustainable Farms compared unfenced dams to dams that had been revegetated and fenced. They found revegetating on the edge of fenced dams led to an increase in aquatic water plants in the water body and gains in vegetation outside the dam but inside the fenced area.
“By allowing that ground layer of vegetation to build up, which we achieve by excluding livestock, we introduced this natural filtration system,” Dave said.
“That does a really good job of filtering water as it passes through and intercepts some of the nutrients and runoff that would otherwise make its way into the dam, leading to significant gains in water quality.
“Once the water quality is better and native plants came back, we also saw an increase in the number of freshwater macro invertebrates, such as water bugs, and in bird activity.”
NSW Biodiversity Conservation Trust project officer Sue Pritchard said the agency’s regional staff could advise conservation agreement-holders on the best management actions for their property.
Participants of our online conservation management webinar, hosted by the NSW Biodiversity Conservation Trust each quarter, also heard that enhancing farm dams could have wider environmental outcomes than the conservation benefits for local species.
Dave said Sustainable Farms had collaborated with Deakin University researchers to look at greenhouse gas emissions from farm dams.
“Findings showed that by reducing nutrients like nitrogen and phosphorus and increasing the oxygen in water largely by the increase in aquatic plants within the water, methane fluxes were reduced by approximately 56 per cent,” he said.
“Methane is a really powerful greenhouse gas, so that's quite a significant outcome.”
For more information about managing farm dams in private conservation areas, visit bct.nsw.gov.au/farm-dams.