35 people attended a Healthy Farm Dam Workshop at the Dalton Hall and the property” Meriden” on Saturday 21st July with Dr David Hunter – Threatened Species Officer, NSW Office of Environment and Heritage and Tony Cox , District Agronomist with the Department of Primary Industries.
Dr Hunter, a renowned frog expert, explained that the agricultural landscape and farm management are key to future biodiversity management because typically threatened species are found in the agricultural landscape not in National Parks, so there is a need to marry agricultural practices with biodiversity conservation.
In 2009 ,at nearby Blakney Creek, Dr Hunter and colleague, Luke Pearce discovered the Nationally threatened Yellow Spotted Bell Frog which had been, unseen in the wild for the past 30 years, prompting a campaign by the Lachlan CMA and the Office of Environment and Hertage, “Fish Frogs and Hollow Logs” aimed at assisting landholders to manage the habitat of this endangered species and others. More information about this project can be found at https://upperlachlan.files.wordpress.com/2012/04/c_2011_003_fish_frogs_and_hollow_logs1.pdf
Dr Hunter believes that biodiversity conservation does not, have to be at the expense of productivity and, in fact, agricultural productivity can be enhanced by biodiversity.Frogs play an important role in ecological processes due to their lifecycle which bridges two core elements of the environment, water & terrestrial. They consume large amounts of food from the wetland to the terrestrial environment.
Frogs are a good indicator species, if there is an abundance of frogs then it can be an indication that things are going well. The entire body of a frog is a mucus membrane therefore if there are pathogens and toxins they are first felt by the frogs. Like canaries, if there is a problem in the system then the frogs are the first to go.
Whilst there are many threatening processes affecting frog species that we do not have the capacity to influence such as the pathogen amphibian chytrid fungus( introduced into the Australian environment during the 1970’s and is causing amphibian declines and extinctions all around the world); other pathogens and increasing effects of climate change; We can reduce their impacts by ensuring that the frogs have a good quality habitat and understanding some of the critical elements in their lifecycle.
- In the case of the Booroolong Frog this is about ensuring that they have the crevices that they need for laying their eggs.
- Diversity of structure in wetland systems
- It is critical to have more than one great wetland or habitat to ensure survival in diverse times; changes can happen rapidly such as in the river system losing deep holes to sediment after a flood which can happen overnight meaning that in the next drought there will be no free standing water.
- Complexity in habitat to assist frogs to co-exist with predators.
Here is a link to a great video with Dr David Hunter
Tony Cox a District Agronomist for the DPI explained how improved water quality can benefit production, biodiversity and the environment
The key management options for addressing water quality issues;
- Maintaining 80% or more groundcover in paddocks to prevent erosion.
- Where possible, fence off dams, drainage lines and spillways to prevent stock access
- Stock can be given restricted access to dams with placement of gravel and fencing to reduce turbidity and their ability to stand in the water at depth.
- Drainage lines and spillways should have 100% ground cover and a high herbage mass to slow the flow of water and encourage deposition of sediments; crash grazed when necessary, provided there isn’t heavy rain forecast.
- Planting paddock trees away from the dam to prevent stock from ‘camping’ too close and fouling the water.
- Design tree plantings to reducing wind on dam to reduce damage to dam walls.
- Construct dams with a variety in depth and jagged shorelines to maximise habitat.
- Plant a range of species to create a variety of habitats and encourage biodiversity in animal species.
- Include plants that encourage ‘biofilm action’. Biofilm consists of microorganisms that grow on the plants and filter out nutrients and sediments giving it a brown slimy appearance.
- Maintain a buffer zone when applying fertilisers and/or pesticides.
More information about Healthy Farm Dams can be found http://www.southern.cma.nsw.gov.au/documents/The%20Farm%20Dam%20Handbook.pdf