Valuing the forest ecosystem
The benefits and services of forests
Planted and natural forests provide a range of benefits or services to people and the environment. Ecosystem services can be categorised as:
- Provisioning or financial benefits from wood, fuel and fibre for example
- Regulating, e.g. carbon capture, avoided erosion, water regulation, habitat provisioning
- Social and cultural, e.g. recreation, biodiversity, spiritual
- Supporting services, such as the biological, chemical and physical processes that underlie the provision of the other services.
Services such as wood, fibre, bioenergy production and carbon sequestration have a market value and can be accounted for in policy and land management decision making. Others, such as erosion prevention, biodiversity and recreation, are more difficult to quantify and their value is not well established.
Scion's work focusses on developing the tools and economic models to estimate the value of both market and non-market ecosystem services associated with forests and other land uses. We are building a comprehensive picture of the true value of planted forests; timber value; plus carbon stocks, biodiversity, habitats, clean water, recreation and other services.
This enables policy makers and forest owners to consider production forests for more than just their timber value when making decisions for public and private good. Considering other services also strengthens the New Zealand forest industry’s licence to operate.
- How we can value forest ecosystem services
- About the ecosystem services provided by the Wenita Forest estate near Dunedin [pdf]
Capturing carbon for a healthier future
Trees accumulate and store carbon over their life, making plantation and indigenous forests an effective means to offset a large portion of New Zealand’s greenhouse gas emission as part of the country’s commitment to the Kyoto Protocol.
Carbon capture is becoming ever more important in the challenge to lessen the effects of climate change. Scion has contributed to the Royal Society of New Zealand’s report on climate change mitigation in 2016. The Transition to a Low-Carbon Economy for New Zealand includes forestry and other land-uses as an opportunity for action now.
The amount of carbon stored in New Zealand's planted forests was 454 tonnes in 2012. Based on the 2016 carbon price of NZ$18 per tonne (2016), the stored carbon was worth NZ$81 billion.
Carbon in trees
Scion has worked closely with government agencies to develop accurate carbon modelling systems for New Zealand’s forests and to develop climate change mitigation strategies. They have been used to improve the New Zealand Land Use and Carbon Analysis System (LUCAS), which is run by the Ministry for the Environment to monitor carbon stocks in planted forests; to meet our reporting requirements under the Kyoto Protocol; and as a support tool for carbon forestry.
We have also contributed to the international guidelines for greenhouse gas accounting, developed by the Intergovernmental Panel on Climate Change (IPCC). These guidelines are used by all countries for the annual reporting of greenhouse gas budgets under the United Nations Framework Convention on Climate Change.
Soil carbon stocks
Globally, soils are estimated to contain approximately 1,500 giga tonnes of organic carbon (to a depth of one metre), more than the amount in vegetation and the atmosphere.
The effects of soil sequestration can be reversed. If the soil is disturbed or tilled, the soil becomes a net source of greenhouse gases. Typically after 15 to 30 years of sequestration, soil becomes saturated and ceases to absorb carbon. This implies that there is a global limit to the amount of carbon that soil can hold.
Scion has developed methods for measuring soil carbon stocks to support New Zealand’s commitment to sustainable forest management, government involvement in international forestry agreements such as the Montreal Process, and the forestry sector’s adoption of forest certification mechanisms.
Carbon forestry is the establishment of new forests for the purpose of earning carbon credits that can be sold on domestic and international markets.
Scion has broad experience of carbon accounting in planted forests, soil carbon, and the impacts of different management techniques. We can provide investors in carbon forestry with detailed analyses on projected production levels, economic outcome and potential risk. Our research includes:
- Species suitability based on projected forest productivity, climate, topography, soil characteristics etc
- Economic and carbon modelling
- Risk analysis based on site and species
- Forest establishment, intensive silvicultural systems and harvesting technologies
- Ongoing monitoring
- Specialist commercial nursery facility for the propagation of species likely to be used for carbon forestry.
Listen to talks on:
- Carbon Footprint Tools for Forestry [YouTube]
- Forests for wood production, carbon sequestration and erosion control [YouTube]
Water filtration, storage and movement are affected by forests, influencing the physical, chemical and biological quality of surface waters.
- Assesses the changes in water quality during the planted forestry cycle from afforestation through to harvesting (the freshwater environment)
- Compares water quality from planted forests with other land uses in New Zealand
- Looks at ways to value the regulating benefits of forests on water quality.
Planting pasture in forest significantly improves a wide range of water quality attributes such as stream temperature, nutrient and sediment concentrations and microbial contamination within 4-6 years of planting. In particular, nitrogen and phosphorus levels are lowered.
We have carried out case studies looking at the effects of changing land use in the Ohiwa catchment (Bay of Plenty) and the central North Island that show how careful consideration of ecosystem benefits can benefit the environment without affecting provisioning services such as food production. In many cases, complementary land use (a mixture of farming and forestry) is more beneficial than a single land use.
- Ecosystem services in the Ohiwa catchment
- How complementary land uses can benefit multiple industries
Erosion and flood control
Forested land traps and stores water. Reducing large water flows from heavy rain and storms helps reduce flooding and erosion and sediment making its way into streams and rivers.
Quantifying the non-market value of erosion control
Values can be assigned to erosion avoidance and flood control by looking at the costs of removing sediment during water treatment, dredging silted harbours and repairing infrastructure damage and lost production after storms. The value of avoided sedimentation through erosion control in New Zealand is estimated to be $6.50 per cubic metre of sediment.
The calculated values have been included in Scion’s Forest Investment Finder (FIF) and can be used to identify the wider benefits of forestry (beyond timber value).
Social and cultural services
Biodiversity in planted forests
Biodiversity describes the variety of plant and animal life in a particular habitat. Scion research has shown that New Zealand’s planted forests support a rich diversity of native flora and fauna, including around 180 rare and threatened species. This work has altered the international community’s perception of New Zealand forestry. It also contributes to maintaining market access for our forest products through helping plantation forests gain Forest Stewardship Council certification.
Native species found in planted forests include kiwi, kārearea (bush falcon) and bats as well as reptiles, insects, plants and fungi. While the levels of biodiversity found are not as high as those in indigenous forests, they are far higher than the levels found in agricultural and pastoral land.
Biodiversity of stream and rivers
Forests play an important role in maintaining the biodiversity of the fresh waterways within their catchment, and downstream. They provide a source of:
- High quality water, essential for biodiversity.
- Shade and cool water temperatures, which are essential for a healthy aquatic environment.
- Woody material as a habitat for many native species, such as Galaxis spp (whitebait) and insects, as well as trout.
- Valuable nutrients by way of leaves, insects and bird droppings.
Scion's work protecting and enhancing the ecosystems that support this natural diversity includes:
- Working with the forest industry to minimise the disruptions caused by harvesting operations, such as roading, stream crossings, riparian activities
- Planting more native plantations, forest restoration or reafforestation for better catchment management
- Using forests and wetlands for stormwater and effluent management.
New Zealanders are willing to pay NZ$20-30 to hear and see kiwi and native falcons in planted forests according to our research. Results of economic valuation studies provide the tools to value production forests for more than just their timber value.
Recreation and health
Planted forests, especially those near towns and cities, provide the opportunity for recreational activities such as walking, running, mountain biking, horse riding and hunting. The activities directly benefit those that take part in terms of health and wellbeing (and meat in the case of hunting). Indirect benefits include supporting tourism and local economies. Our research focusses on valuing these benefits.
The Redwoods and Whakarewarewa Forest on the edge of Rotorua are popular destinations for tourists, walkers/runners and mountain bikers. By looking at the money people 'spend' carrying out activities in the area, for example, distance travelled to reach the forest, time spent there, etc, it is possible to work out the value of a mountainbike ride or walk, and the recreational value of the forest.
Towards understanding cultural values
Our research on the cultural, spiritual, heritage and aesthetic values associated with the land is focussing on ways to define and measure these. Work on understanding the impacts of pest wilding conifers on sites of cultural value is an example of this.
National Ecosystem Services Forum
Scion hosts the annual National Forest Ecosystem Services forum. The forum provides a platform for scientists, government agencies, research organisations and forest industry representatives to address issues on ecosystem services at a national and international level. Issues include:
- The role of planted forests
- Increasing the awareness of forest ecosystem services
- New Zealand research in an international context
- Benchmarking progress on policy, provision, and markets for forest ecosystem services
- Global perspectives.
Dr Richard Yao, Resource Economist email@example.com