Post-fire Forest Residue Mulch [Portugal]

acolchoado, aplicação de restos vegetais

technologies_1186 - Portugal

Completeness: 73%

1. General information

1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Key resource person(s)

SLM specialist:
SLM specialist:

Keizer Jan Jacob

Universidade de Aveiro-CESAM


SLM specialist:
Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Preventing and Remediating degradation of soils in Europe through Land Care (EU-RECARE )
Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Catastrophic shifts in drylands (EU-CASCADE)
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
University of Aveiro (University of Aveiro) - Portugal

1.3 Conditions regarding the use of data documented through WOCAT

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:


2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Forest residue mulch is spread immediately after a wildfire in order to prevent soil erosion and reduce overland flow.

2.2 Detailed description of the Technology


In two areas of eucalypt plantations affected by wildfires in central Portugal in 2007 and 2010, the research team of the University of Aveiro set up two experiments in order to test the effect of forest residue mulching as a soil erosion mitigation technique. Forest residues such as chopped eucalypt bark mulch was spread over a group of erosion plots, and was compared to an untreated group of plots.
The mulching was applied at ratios of 8.7 and 10.8 Mg ha-1 provided an initial ground cover of 70 to 80%, and was found to reduce post-fire runoff by 40-50% and soil erosion by 85-90%, respectively.

Purpose of the Technology: The increase in ground cover will decrease post-fire soil erosion by reducing raindrop impact over the ashes and bare soil, and decrease the runoff amount by increasing water surface storage, decreasing runoff velocity, and increase infiltration.
Ideally, post-fire mulching must be carried out immediately after the fire, in order to prevent that the first autumn rainfall events fall over the bare and unprotected burnt soils. It is intended for places in which burnt severity was moderate to high and where there are important values at risk, such as water reservoirs, populations, industries, human and wild life.

Establishment / maintenance activities and inputs: The chopped bark mulch was obtained at a depot 20 km from the burnt area, where eucalypt logs are debarked and then transported to a paper pulp factory. The bark is chopped into fibers and are typically transported to a biomass energy plant. We used these 10–15 cm wide 2–5 cm long bark fibers as the source for our mulching experiment. The chopped bark mulch decays very slowly (around 20% less ground cover per year) which was very useful in cases of low re-growth of natural vegetation.

Natural / human environment: The eucalypt trees in the region are typically planted as monocultures for paper pulp production, and harvested every 7-14 years. The landscape reflects a long history of intense land management, with a mosaic of (semi-)natural and man-made agricultural and afforested lands. Since the 1980´s, however, wildfires have increased dramatically in frequency and extent, aided by a general warming and drying trend but driven primarily by socio-economic changes.

2.3 Photos of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment



Region/ State/ Province:

Portugal/Beira Litoral

Further specification of location:

Sever do vouga/ Pessegueiro do Vouga, Ermida

Specify the spread of the Technology:
  • evenly spread over an area
If precise area is not known, indicate approximate area covered:
  • < 0.1 km2 (10 ha)

Total area covered by the SLM Technology is 1.0E-5 m2.

The experiment was carried out in grous of small bounded plots of 0.25, 16 and 100 m2.

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • less than 10 years ago (recently)

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • during experiments/ research
Comments (type of project, etc.):

The first experiment was carried out in 2007.

3. Classification of the SLM Technology

3.2 Current land use type(s) where the Technology is applied

Forest/ woodlands

Forest/ woodlands

  • Tree plantation, afforestation
Type of tree:
  • Eucalyptus species
Products and services:
  • Timber
  • Fuelwood

Major land use problems (compiler’s opinion): Increased runoff and soil erosion, resulting in a decrease of on-site fertility and derived off-site effects such as loss of water quality, reservoirs water volume storage, higher risk of flooding and human beings damage.

Major land use problems (land users’ perception): Loss of wood resources and productivity.

Plantation forestry: eucalypt are logged and left to regrow from stumps each 7-10 years

Forest products and services: timber, fuelwood

Number of growing seasons per year: 1

3.5 SLM group to which the Technology belongs

  • improved ground/ vegetation cover

3.6 SLM measures comprising the Technology

agronomic measures

agronomic measures

  • A1: Vegetation/ soil cover

Main measures: agronomic measures

Type of agronomic measures: mulching

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wt: loss of topsoil/ surface erosion
  • Wo: offsite degradation effects
chemical soil deterioration

chemical soil deterioration

  • Cn: fertility decline and reduced organic matter content (not caused by erosion)
water degradation

water degradation

  • Hs: change in quantity of surface water
  • Hp: decline of surface water quality

Main type of degradation addressed: Wt: loss of topsoil / surface erosion, Hs: change in quantity of surface water, Hp: decline of surface water quality

Secondary types of degradation addressed: Wo: offsite degradation effects, Cn: fertility decline and reduced organic matter content

Main causes of degradation: crop management (annual, perennial, tree/shrub) (Eucalypt monocultures are prone to suffer wildfires), deforestation / removal of natural vegetation (incl. forest fires), disturbance of water cycle (infiltration / runoff) (Increased runoff is observed after wildfires), Heavy / extreme rainfall (intensity/amounts) (Burnt areas are very sensitive to high intensity events), other natural causes (avalanches, volcanic eruptions, mud flows, highly susceptible natural resources, extreme topography, etc.) specify (Sediment deposition can decrease the storage volume of reservoirs.)

Secondary causes of degradation: floods (Overland flow can be extremely high after forest fires), inputs and infrastructure: (roads, markets, distribution of water points, other, …) (Roads concentrated the runoff and are greatly degraded.)

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:
  • prevent land degradation
  • reduce land degradation

Main goals: prevention of land degradation, mitigation / reduction of land degradation

4. Technical specifications, implementation activities, inputs, and costs

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Forest residue mulch is spread as homogeneous as possible over steep areas (steeper than 15º) burnt at high fire severity (represented in green and 1). Other areas which are flat (2) and burnt at low severity or only partially burnt (3) must be avoided.

Location: Ermida. Sever do Vouga/ Portugal

Date: 15 9 2010

Technical knowledge required for field staff / advisors: low (forest residue mulching is highly effective in all situations, but applications using short fibres mulching as well as low intensity burning should be avoided.)

Technical knowledge required for land users: low

Main technical functions: control of raindrop splash, control of dispersed runoff: retain / trap, control of concentrated runoff: retain / trap, control of concentrated runoff: impede / retard, control of concentrated runoff: drain / divert, improvement of ground cover, improvement of water quality, buffering / filtering water, sediment retention / trapping, sediment harvesting

Secondary technical functions: control of dispersed runoff: impede / retard, reduction of slope angle, increase of surface roughness, increase in organic matter, increase of infiltration, increase / maintain water stored in soil, increase of groundwater level / recharge of groundwater

Material/ species: chopped bark, cork, stems, leaves, straw/eucalypt, pine, oaks, shrubs
Quantity/ density: 2-10t/ha
Remarks: material with low density (straw) need less weight for achieving the final goal: 70% ground cover.


Departamento de Ambiente e Ordenamento. Universidade de Aveiro.

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):


If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:


Indicate average wage cost of hired labour per day:


4.3 Establishment activities

Activity Timing (season)
1. Labour
2. Transportation (small truck for carrying persons and material)
3. Eucalypt chopped bark mulch
4. Others

4.4 Costs and inputs needed for establishment

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Labour ha 1.0 192.0 192.0 100.0
Equipment Machine use ha 1.0 51.2 51.2 100.0
Other Forest residue mulch ha 1.0 307.6 307.6 100.0
Other Others ha 1.0 64.1 64.1 100.0
Total costs for establishment of the Technology 614.9
Total costs for establishment of the Technology in USD 788.33

Duration of establishment phase: 1 month(s)

4.6 Costs and inputs needed for maintenance/ recurrent activities (per year)


The prices were determined in winter 2012 for central Portugal. It is intended that mulch is applied only once, and thus maintenance is not needed. In other regions other forest residues can have a higher availability. Straw, needles, deciduous leaves or chopped shrubs are lighter compared to eucalypt chopped bark, slash stems or wood chips, and thus, can be easier to apply and transport. However, the lighter the material, the easier it can be blown away in windy areas.

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Accessibility and steepness will raise the costs, but selecting forest residues with lower densities as well as applying them in horizontal strips along the slope can reduce the application rates and the costs.
For large and inaccessible areas some researchers indicated that helicopters can reduce the costs.

5. Natural and human environment

5.1 Climate

Annual rainfall
  • < 250 mm
  • 251-500 mm
  • 501-750 mm
  • 751-1,000 mm
  • 1,001-1,500 mm
  • 1,501-2,000 mm
  • 2,001-3,000 mm
  • 3,001-4,000 mm
  • > 4,000 mm
Agro-climatic zone
  • humid
  • sub-humid

Thermal climate class: subtropics

Thermal climate class: temperate

5.2 Topography

Slopes on average:
  • flat (0-2%)
  • gentle (3-5%)
  • moderate (6-10%)
  • rolling (11-15%)
  • hilly (16-30%)
  • steep (31-60%)
  • very steep (>60%)
  • plateau/plains
  • ridges
  • mountain slopes
  • hill slopes
  • footslopes
  • valley floors
Altitudinal zone:
  • 0-100 m a.s.l.
  • 101-500 m a.s.l.
  • 501-1,000 m a.s.l.
  • 1,001-1,500 m a.s.l.
  • 1,501-2,000 m a.s.l.
  • 2,001-2,500 m a.s.l.
  • 2,501-3,000 m a.s.l.
  • 3,001-4,000 m a.s.l.
  • > 4,000 m a.s.l.
Comments and further specifications on topography:

Altitudinal zone: 101-500 m a.s.l. (300m)

5.3 Soils

Soil depth on average:
  • very shallow (0-20 cm)
  • shallow (21-50 cm)
  • moderately deep (51-80 cm)
  • deep (81-120 cm)
  • very deep (> 120 cm)
Soil texture (topsoil):
  • coarse/ light (sandy)
  • medium (loamy, silty)
Topsoil organic matter:
  • high (>3%)
If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

Topsoil organic matter is high (Around 10 % between 0 to 5 cm of soil depth)
Soil fertility is high-medium
Soil drainage/infiltration is medium (Dependent on the soil water repellence cycles, characteristics of eucalypt and pine plantations on the area.)
Soil water storage capacity is medium

5.4 Water availability and quality

Ground water table:

5-50 m

Availability of surface water:


Water quality (untreated):

good drinking water

5.5 Biodiversity

Species diversity:
  • medium

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • mixed (subsistence/ commercial)
  • commercial/ market
Off-farm income:
  • less than 10% of all income
Relative level of wealth:
  • poor
  • average
Individuals or groups:
  • employee (company, government)
  • women
  • men
Indicate other relevant characteristics of the land users:

Land users applying the Technology are mainly common / average land users

Population density: 50-100 persons/km2

Annual population growth: negative

50% of the land users are average wealthy.
40% of the land users are poor.
10% of the land users are poor.

5.7 Average area of land used by land users applying the Technology

  • < 0.5 ha
  • 0.5-1 ha
  • 1-2 ha
  • 2-5 ha
  • 5-15 ha
  • 15-50 ha
  • 50-100 ha
  • 100-500 ha
  • 500-1,000 ha
  • 1,000-10,000 ha
  • > 10,000 ha
Is this considered small-, medium- or large-scale (referring to local context)?
  • small-scale

5.8 Land ownership, land use rights, and water use rights

Land ownership:
  • communal/ village
Land use rights:
  • communal (organized)
  • individual
Water use rights:
  • open access (unorganized)

5.9 Access to services and infrastructure

  • poor
  • moderate
  • good
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
  • poor
  • moderate
  • good
  • poor
  • moderate
  • good
roads and transport:
  • poor
  • moderate
  • good
drinking water and sanitation:
  • poor
  • moderate
  • good
financial services:
  • poor
  • moderate
  • good

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Water availability and quality

water availability for livestock


irrigation water availability


demand for irrigation water

Income and costs

expenses on agricultural inputs

Comments/ specify:

Eucalypt chopped bark mulch increases expenses if not funded by the Government

Socio-cultural impacts

SLM/ land degradation knowledge


conflict mitigation

Comments/ specify:

Less damage to off-site neighbouring properties

Improved livelihoods and human well-being

Comments/ specify:

Public awareness of the technology is very limited. It is necessary to show it to landowners and stakeholders and increase dissemination.

Ecological impacts

Water cycle/ runoff

water quality


surface runoff


groundwater table/ aquifer




soil moisture


soil cover


soil loss


soil organic matter/ below ground C

Biodiversity: vegetation, animals

animal diversity


beneficial species

Other ecological impacts

Hazard towards adverse events


6.2 Off-site impacts the Technology has shown

water availability


downstream flooding


downstream siltation

Comments/ specify:

If applied in large areas

groundwater/ river pollution


buffering/ filtering capacity


wind transported sediments


damage on neighbours' fields


damage on public/ private infrastructure

Comments/ specify:

If applied in large areas upslope

6.3 Exposure and sensitivity of the Technology to gradual climate change and climate-related extremes/ disasters (as perceived by land users)

Gradual climate change

Gradual climate change
Season increase or decrease How does the Technology cope with it?
annual temperature increase well

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
local rainstorm well
local windstorm well
Climatological disasters
How does the Technology cope with it?
drought well
Hydrological disasters
How does the Technology cope with it?
general (river) flood not well

Other climate-related consequences

Other climate-related consequences
How does the Technology cope with it?
reduced growing period not known

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?
Short-term returns:


Long-term returns:

neutral/ balanced

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
Short-term returns:

slightly positive

Long-term returns:

slightly positive

6.5 Adoption of the Technology


Comments on acceptance with external material support: The technology has been tested by scientific researchers and it is very effective, but not broadly implemented.

Comments on spontaneous adoption: The technology has been tested by scientific researchers researchers and it is very effective, but not broadly implemented.

There is no trend towards spontaneous adoption of the Technology

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
It will prevent sediment movement and accumulation over roads and downslope properties
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
It is a technology very easy to apply, with low failure possibilities and a strong soil erosion control

How can they be sustained / enhanced? Some researchers found better performance by grinding the mulch and selecting only the longest fibres.
The material is readily available (residues from the main forest specie affected by the wildfire)

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

Weaknesses/ disadvantages/ risks in the land user’s view How can they be overcome?
The costs are not very high, but enough to discourage the landowners to cover the expenses. Look for Government funding, educate land owners about soil erosion conservation techniques.
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
When applying high density mulches the application labour requirements and costs will be higher Distribute the mulch in strips, use lighter mulches, grind to remove the fine fibres or maybe try to reduce the application rate. It is also possible to use in-situ chopping tree machines or to use aerial application methods, such as helicopters to reduce the application costs.

7. References and links

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Prats S. A., Macdonald L.H., Monteiro M.S.V., Ferreira A.J.D., Coelho C.O.A., Keizer J.J.,2012. Effectiveness of forest residue mulching in reducing post-fire runoff and erosionin a pine and a eucalypt plantation in north-central Portugal. Geoderma 191, 115-124.

Available from where? Costs?


Title, author, year, ISBN:

Shakesby R.A., Boakes D.J., Coelho C.O.A., Gonçalves A.J.B., Walsh R.P.D., 1996. Limitingthe soil degradational impacts of wildfire in pine and eucalyptus forests in Portugal.Applied Geography 16, 337-335.

Available from where? Costs?


Title, author, year, ISBN:

Robichaud, P.R., Lewis, S.A., Ashmun, L.E., Wagenbrenner, J.W., Brown, R.E., 2013a.Postfire mulching for runoff and erosion mitigation Part I: Effectiveness at reducinghillslope erosion rates. Catena 105, 75–92.

Available from where? Costs?


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