Ecosystem accounts define explicit and spatial trade-offs for managing natural resources
Decisions about natural resource management are frequently complex and vexed. Now, ecosystem accounting has the potential to re-frame these debates and contribute to the policy process.
The paper in Nature Ecology & Evolution is here: http://go.nature.com/2hzbcCJ
The tall, wet eucalypt forests in the Central Highlands are awe-inspiring – giant trees up to 70m high and 4m diameter. It can be difficult to sight the top of trees to measure height and it takes two people to walk around the tree and hold a diameter tape.
Beneath the tree canopy is a complex structure of mid-storey trees and shrubs, as well as lush tree ferns in damp pockets. The forest is an enchanting place where many visitors find peace and beauty. It is home to a wide range of plant and animal species, including some threatened and critically endangered. What an amazing place to have just 100 km from the city of Melbourne?
Tall, wet eucalypt forests of the Central Highlands with complex structure and species composition. Image: Dave Blair
People use the ecosystem assets and services from this forest environment for many different purposes and they contribute to many industries. The catchments provide the main water supply for Melbourne and surrounding area. Native forests, softwood and hardwood plantations supply wood for sawlogs and pulp. The biomass in the forest, in the form of living and dead trees, shrubs, litter and fallen logs, as well as soil, store large amounts of carbon. The forests, streams, reservoirs, mountain peaks, birds and animals attract many local visitors and tourists. The surrounding agricultural area also relies on ecosystem services, such as pollination, water, nutrient cycling and erosion control. Managing these various land use activities within a region can be problematic when some activities diminish the provision of ecosystem services for other activities.
Catchments in the Central Highlands are important sources of water for Melbourne. Image: Dave Blair
In the Central Highlands, the main cause of conflict between uses of different ecosystem services is the harvesting of native forests. Harvesting is by clearfelling and slash burning. Regenerating forests are younger, even-aged and with lower species composition. These characteristics reduce the condition of the ecosystem to support services for biodiversity, carbon, water and recreation.
Of particular concern is the diminishing number of large, old, hollow-bearing trees that provide nest sites for arboreal marsupials, like possums and gliders, and many species of birds and invertebrates. Many of these large trees were lost in a wildfire in 2009, and the continued clearfell logging has progressively reduced numbers of trees suitable for nest sites. Now, less than 3% of old growth forest remains in this region. Many people have advocated for a change in management of the forest to protect endangered species – scientists, environmental groups and local communities. However, the arguments about protecting biodiversity have not influenced decision-makers or people within the timber industry.
Measuring diameters of Eucalyptus regnans trees. Image: Dave Blair
As researchers who are committed to improving management of our natural resources, and have been working on various scientific studies in this forest for many years, we wanted to find a better way of tackling the issue. The System of Environmental-Economic Accounting afforded the capacity to evaluate ecosystem assets, the production of goods and services, and the people who benefit, in an holistic manner. Demonstrating the value of ecosystem services to economic activities in a common currency has provided a more complete picture on which to base decisions. Government departments, politicians, the media and local communities are listening our results seriously, and we are hopeful that this form of presenting information and analyzing options will improve natural resource management decisions.