How to use QUICK INDEX Ecosystem Services

Ecosystem Services


You are here: Home > Ecosystem Services > Buffering Against Extremes


Buffering Against Extremes

The role of ecosystems in maintaining normal situations (e.g. buffering against extreme natural events such as droughts, floods, storms, tsunamis), natural irrigation and drainage (e.g. watertable regulation) that are important to the provision of safety to human life, structures and other assets.

 

Millennium Ecosystem Assessment Service Category

Regulating Services

 

What is buffering against extremes and how is it derived?

Costal ecosystems (e.g. wetlands, rocky shores and beaches) buffer coastal developments from extreme events such as winds, waves and storms surges.

Often we are reminded of the merciless power of natural forces when extreme events devastate landscapes, homes and communities in the form of heatwaves, droughts, floods, storms and tsunamis. Although nature can be fierce, nature also provides the infrastructure to buffer against these extreme events (e.g. wetlands, beaches and rockyshores). It is not enough however just to prepare ourselves to manage for 'normal situations' (e.g. average rainfalls and temperatures) there is a need to prepare for and adapt to greater climatic variability and extreme weather events. Additionaly, there is a need for contingency planning and emergency response that will cover all extremes (hot, cold, dry, wet and windy/stormy weather conditions). The consequences of under preparation for and response to extreme events is often irreversibly costly when measured biophysically, economically and socially.     

The level of service provided depends on the geographic location, spatial extent of the specific natural systems that could provide buffers against certain extremes and their inherent condition. That is, where they are and whether they are healthy in the ways that they resist and recover from impacts from a range of natural forces (i.e. whether they are robust and resilient). Specifically, if mangroves are to buffer against storm surge the trees must be in a sufficient linear mass (i.e. wide enough and long enough strip) at a location that is itself relatively stable and the vegetation mass must be robust and resisting conditions that would weaken the plants (e.g. insects such as borers).

Table 1 below presents the magnitude that different ecosystem functions contribute to buffering against extreme events (relative to other ecosystem functions). Regulating functions play an important role in the provision of this service. The processes that regulate atmospheric circulation and weather patterns (climate regulation) operate at global and regional scales and spatially encompass a wide range of ecosystem conditions. Notwithstanding the issues of scale, regional climatic and local weather conditions are important for maintaining temperatures and precipitation that are comfortable for human habitation and cultivation. The capacity of soil, regolith and vegetation to buffer the effects of wind, water and waves through water and energy storage capacity and surface resistance (disturbance regulation) will determine the severity of impacts from extreme events on natural systems and society.

The synergistic combination of soil profile and vegetative cover is important for buffering against extremes. Specifically, soils store water and vegetation enhances infiltration and provides surface resistance. Together they contribute to reducing runoff. Degraded soils and devegetated landscapes have a reduced capacity to regulate water and result in greater erosion, loss of productive soils in terms of bio-productivity. Soil properties (e.g. depth, surface texture, porosity), the type of vegetation structure and the spatial extent of the cover are important buffering elements against intensive rainfall events as well, limiting the transportation of air pollutants that may for example result from fires.

 

Table 1:The relative magnitude (to other ecosystem functions) each ecosystem function contributes to Buffering Against Extremes.

Ecosystem Function Category Ecosystem Function 0
1
2
3
4
5
Regulating Functions
Gas Regulation





Climate Regulation





Disturbance Regulation





Water Regulation





Soil Retention





Nutrient Regulation





Waste Treatment and Assimilation





Pollination





Biological Control





Barrier Effect of Vegetation





Supporting Functions
Supporting Habitats





Soil Formation





Provisioning Functions
Food





Raw Materials





Water Supply





Genetic Resources





Provision of Shade and Shelter





Pharmacological Resources





Cultural Functions
Landscape Opportunity





 

ARE HUMAN INPUTS REQUIRED TO FACILITATE buffering against extremes?

Floodplains slow moving water protecting human life and structures.

Nature's infrastructure to buffer against extreme events is provided free of charge to humans. Human made constructs for example, seawalls and artificial reefs that have been provided to reduce the impacts of storm waves and drainage channels to regulate water, need careful evaluation. On one hand, these structures can become ecosystems as they are colonised by flora and fauna. On the other hand, their construction may have harmed (other) natural systems and although in the short term they protect assets and infrastructure they could result in ecosystem degradation in the future (as they fail under the combined forces of extreme events and lack of funding to maintain their structures). Human made structures have also been appplied to  conserve remnant ecosystems and ensure they do not cross their tipping points or alternatively to compensate for losses where they have.

Human made barriers are difficult to deal with as it raises questions as to the veracity of comparing the buffering role of natural systems with the built capacity of human made systems. Mono-species planting of shade and shelter trees may moderate ground temperatures and break land surface deflating winds with or without providing compensating animal habitats. Human made structures such as flood barriers, storm water retention systems and drainage channels may work as a substitute for the provision of this service but raises questions such as, what is the real value lost from the clearing of that ecosystem? What is the full cost of this substitution? And are there ways to design development around the function of the landscape?

 

Are there any barriers to people receiving this ecosystem service and its benefits?

Due to the nature of the environment and natural processes knowing no anthropocentric boundaries, buffering against extremes is a public good (e.g. no matter where this service is derived no one person owns it and or can exclude others from experiencing this service - it is provided to all SEQ residents). However, if the ecosystems providing this service are derived on private property, management of that ecosystem is at the discretion of the property owner (subject to government zoning and legislation).

Degradation or loss of important ecosystems therefore has the potential to provide a barrier to other residents receiving this service (e.g. the clearing of wetland ecosystems in one area can lead to flooding on a much wider scale affecting a much wider population). Apart from the land tenure in some circumstances, there does not appear to be any other social, environmental or economic barriers preventing people from accessing this service. Careful land-use planning is essential to ensure the buffering of extreme events and security is provided to all people and their property. 

This ecosystem service provides many benefits that contribute both directly and indirectly to the well-being of the SEQ community. The Constituents of Well-being this ecosystem service contributes to are presented in Table 2 below. Further information on these constituents and how ecosystem services contribute to them can be obtained by clicking on the links in the table.

 

Table 2:The relative magnitude (to other ecosystem services) Buffering Against Extremes contributes to each constituent of well-being.

Well-being Category Constituent of Well-being 0
1
2
3
4
5
Existence
Breathing            
Drinking            
Nutrition            
Shelter            
Health
Physical Health            
Mental Health            
Security
Secure and Continuous Supply of Services            
Security of Person            
Security of Health            
Secure Access to Services            
Security of Property            
Good Social Relations
Family Cohesion            
Community and Social Cohesion            
Freedom of Choice and Action
Social and Economic Freedom            
Self Actualisation            

 

HOW DO WE KNOW IF WE ARE DEGRADING, MAINTAINING OR IMPROVING buffering against extremes?

 

Vegetation regulates atmospheric processes such as temperature and precipitation that influence many extreme events.

Links to other publications and websites

NR & W SEQ Drought
Aust Govt. Disaster Assist
CSIRO Extreme Weather
Gold Coast Beaches
Qld Govt. Floods 2012

There are a range of potential indicators or surrogates that could be used to assess whether this ecosystem service is being received and these would need to be identified and evaluated in relation to specific buffering services. The basic parameters of frequency and intensity of the extreme event (e.g. number of cyclones or severe storms per year in a geographic region, occurrence of hail storms in specific localities, duration of heat waves, rates of erosion and recovery of shorelines) should be collected and analysed (both the event and it's impacts on society) in order to better provide integrated approaches to catchment and coastal management.

The loss, maintenance or improvement in vegetation cover will affect many of the buffering services provided by ecosystems. Maintaining mangrove and seagrass areas are important for buffering the effects of extreme events in coastal areas, along with vegetation in erosion prone areas (e.g. on dunes, on slopes) and aquatic vegetation reduces stream velocities and riverbed and bank erosion in flood events. Satelite and GIS mapping can monitor and measure the area and extent and changes in vegetation cover over time. Arguably, if this ecosystem service is naturally being provided autonomously then the process used to mange the specific components (e.g. vegetated land surfaces) would meet the overarching management requirements for buffering against extremes.

 

How is this ecosystem service currently managed in SEQ?

There is no specific legislation or management plan for this ecosystem service. Legislation however aimed at maintaining ground cover (e.g. the Vegetation Management Act 1999) will assist in the provision of this service. Buffering against extremes should be considered as an integral component of integrated catchment or coastal management and accessing this service is an integral part of the management processes used by public and private sector bodies who are involved. The provision of this service needs to be acknowledged and documented in the policy, planning and project delivery processes.

For more information on this ecosystem service contact can be made with catchment managers, universities, CSIRO, Bureau of Meterology, Department of Environment and Heritage Protection or the Department of Emergency Services.