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European Journal of Forest Research ISSN 1612-4669Volume 131Number 1 Eur J Forest Res (2011) 131:21-34DOI 10.1007/s10342-011-0483-7

Conducting sustainability impactassessments of forestry-wood chains:examples of ToSIA applications

Marcus Lindner, Wendelin Werhahn-Mees, Tommi Suominen, Diana Vötter,Sergey Zudin, Matias Pekkanen, RistoPäivinen, Martina Roubalova, et al.

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ORIGINAL PAPER

Conducting sustainability impact assessments of forestry-woodchains: examples of ToSIA applications

Marcus Lindner • Wendelin Werhahn-Mees • Tommi Suominen •

Diana Votter • Sergey Zudin • Matias Pekkanen • Risto Paivinen •

Martina Roubalova • Petr Kneblik • Franka Bruchert • Erik Valinger •

Ludovic Guinard • Stefania Pizzirani

Received: 16 February 2010 / Revised: 27 September 2010 / Accepted: 7 January 2011 / Published online: 19 February 2011

� Springer-Verlag 2011

Abstract Within the EFORWOOD project, new meth-

odological approaches to assess the sustainability impacts

of forestry-wood chains (FWC) were developed by using

indicators of environmental, social and economic rele-

vance. This paper introduces and discusses the developed

approach and the two main products developed in the

EFORWOOD project: the Database Client and the Tool for

Sustainability Impact Assessment (ToSIA), which hold,

calculate and integrate the extensive information and data

collected. Sustainability impact assessment (SIA) of FWCs

is based on measuring and analysing environmental, eco-

nomic and social indicators for all of the production pro-

cesses along the value chain. The adoption of the method

varies between applications and depends on the specifica-

tion of the FWC in the assessment and what questions are

studied. ToSIA is very flexible and can apply forest-,

product-, industry- and consumer-defined perspectives.

Each perspective influences the focus of the analysis and

affects system boundaries. ToSIA can assess forest value

chains in different geographical regions covering local,

regional, national and up to the continental scale. Potential

issues and scenarios can be analysed with the tool includ-

ing, for example, the impacts of different forest policies on

the sustainability of an FWC. This paper presents how

ToSIA can be applied to solve such diverse problems and

underlines this with examples from different case studies.

Differences in chain set-up, system boundaries and data

requirements are highlighted and experiences with the

implementation of the sustainability impact assessment

methods are discussed. The EFORWOOD case studies

offer valuable reference data for future sustainability

assessments.

Keywords Sustainability impact assessment (SIA) �Decision support system � Forest-based sector � Material

flow � System boundaries

Introduction

The sustainability concept is increasingly applied in policy

development to improve the environmental performance,

This article originates from the context of the EFORWOOD final

conference, 23–24 September 2009, Uppsala, Sweden.

EFORWOOD—Sustainability Impact Assessment of Forestry-wood

Chains. The project was supported by the European Commission.

Communicated by T. Seifert.

M. Lindner (&) � W. Werhahn-Mees � T. Suominen �D. Votter � S. Zudin � M. Pekkanen � R. Paivinen

European Forest Institute (EFI), Torikatu 34,

80100 Joensuu, Finland

e-mail: marcus.lindner@efi.int

M. Roubalova � P. Kneblik

Institute of Forest Ecosystem Research (IFER),

Strasice 299, 33845 Strasice, Czech Republic

F. Bruchert

Forstliche Versuchs- und Forschungsanstalt Baden-Wurttemberg

(FVA), Wonnhaldestraße 4, 79100 Freiburg, Germany

E. Valinger

Department of Forest Resource Management, Swedish

University of Agricultural Science (SLU),

Skogsmarksgrand, 901 83 UMEA, Sweden

L. Guinard

FCBA Institut Technologique,

10 Avenue de Saint-Mande, 75012 Paris, France

S. Pizzirani

Forest Research, Roslin, Midlothian EH25 9SY, UK

123

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DOI 10.1007/s10342-011-0483-7

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social acceptance and viability of economic activities

(Tscherning et al. 2008; Weaver and Jordan 2008). In

addition, companies have adopted the concept to improve

their long-term performance as well as their public per-

ception (Burke and Logsdon 1996; Cruz and Boehe 2008).

To offer support for the decision-making and reporting of

achieving sustainable development targets, a range of

sustainability assessment approaches have been developed

(Uthes et al. 2010; Walter and Stutzel 2009).

Paivinen and Lindner (2008) and Paivinen et al. (2011)

introduced a concept of how the impacts of various activ-

ities on sustainability could be assessed for forest value

chains. This concept was implemented in the Tool for

Sustainability Impact Assessment (ToSIA) as described by

Lindner et al. (2010). ToSIA has been designed to be a

flexible sustainability impact assessment tool which can be

applied to study forestry wood chains (FWCs) at different

scales. An FWC describes the entire life cycle of certain

wood products: from the planting of a tree, over the har-

vesting and production, to the consumption and possible

incineration of the product.

ToSIA will not answer the question whether a single

FWC is sustainable or not. However, it will calculate dif-

ferent flow-dependent indicator values for various chains.

The effects of changes in the FWC between alternatives

can be measured and compared. The ‘‘as-is state’’ of an

FWC, for example, could be compared to alternatives or to

projections. What are the impacts on sustainability of dif-

ferent production alternatives? How is the forest-based

sector developing in regard to its sustainability, if e.g. new

production systems and technologies will be introduced or

if more forests will be taken out of production due to a shift

in the nature conservation policies?

In order to assess the sustainability impacts of changes in

an FWC chain, it is important to conduct the SIA from dif-

ferent perspectives. Forest practitioners look at the FWC as a

value chain that is driven by the forest and its management,

whereas consumers may have a stronger connection to the

wood products with only vague information of the FWC

behind the product. The scales and perspectives of the

applications affect data needs and the type of analysis that

can be performed. One aspect in this context is the question

of cut-off criteria that are used to define the system bound-

aries of the analysis (e.g. Wenzel 1998). In life cycle anal-

ysis, additional data should be added to the analysis if these

are likely to affect the results of the analysis (Guinee 2002).

A different perspective will therefore result also in a different

topology of the analysed FWC: for example, from a forest

management perspective processes concerned with the

impacts on sustainability of imports from overseas into the

region might be irrelevant, whereas from the industry per-

spective especially these imports might be of the highest

interest and should be included in the topology.

The purpose of this paper is to illustrate the method with

one concrete example, present different types of ToSIA

applications for different user perspectives and to discuss,

using examples of the EFORWOOD project (www.efor

wood.org), how these applications influence conditions and

requirements for conducting sustainability impact assess-

ments for the forest-based sector. Furthermore, the

strengths and challenges of the ToSIA approach will be

elaborated and discussed.

Methods

Sustainability impact assessment of changes in FWCs

with ToSIA

The sustainability impact assessment of the forest-based

sector in EFORWOOD builds on the conceptual repre-

sentation of FWCs as chains of value-adding production

processes (Paivinen and Lindner 2008). The structure of

the FWC is given as a topology, which captures the flows

of wood-based products between processes. The topology

of the chain is built with three distinct components: pro-

cesses, products and the connections between processes

called links (Fig. 1).

A process represents a purposeful action, aimed at

increasing the value/utility of a product. A process either

changes a product’s physical properties or moves it to

another location. A process is the entity for most of the

information used in ToSIA; a process is defined by the

information it contains. This also includes input and output

Fig. 1 The three distinct components of the topology, processes with

each one input and output product, and the linkages between the

processes. The example on the left shows how the topology elements

are displayed in the EFORWOOD database client with reference to

product IDs and the name and ID of the processes

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products that define how a process can be connected. Input

products for each process in a chain receive material from

matching output products of previous processes. From

these processes, connected by products and links, a chain

topology is formed, focusing on a special (research)

question and thus describing a case study.

This chain topology is then later used by ToSIA to

calculate the flows of wood-based material throughout the

chain’s processes based on given initializations. Initial-

izations depend on the perspective of the case and the

research question behind the case and can be started e.g.

from the forest resource or from consumed products. Each

process’ performance with regard to sustainability is

characterized with indicators, which are expressed relative

to a unit of material consumed by this process. The current

indicators have been selected to represent the environ-

mental, economic and social pillars of sustainability. Yet,

ToSIA sets no limits to incorporating other indicators, as

long as they can be related to the processes.

In ToSIA, indicators are relating to the incoming

material amount of a process and are used to compute the

calculated process indicator value (Lindner et al. 2010).

Units (e.g. EURO) are defined for all indicators, and the

indicators are given per unit of incoming material flow (e.g.

tons) as illustrated in Table 1 (e.g. labour costs expressed

as €/ton). This incoming material flow can be a mix of

several different products.

Each process has a process unit that is used for all

indicators collected for that process (i.e. the example above

is reported in ‘tons of pellets’). The indicators may be

reported with different process units for different processes

(for example tons for pellets or m3 for saw logs). Because

many different units are used, conversion factors from unit

to unit are required for converting the material flows

between products and processes. For each product in an

FWC, several conversion factors are required. An overview

of the required data for conducting a sustainability impact

assessment with ToSIA is provided in Table 2.

The EFORWOOD Database Client

Operating alongside the ToSIA tool, the Database Client is

another component of the sustainability impact assessment

approach developed in EFORWOOD. The Database Client

is used to visualize, collect and store all the data used by

ToSIA; to define the shape of the FWC topology as well as

to give chain specifications, indicator data and other FWC

parameters. The topology of each FWC is designed with a

graphical design interface called ‘‘chain editor’’ by first

creating needed processes with their products and then

adding processes to a chain and linking them to each other.

Furthermore, existing FWC processes and products are

available to be reused in the creation of new FWCs; this

enables reuse of available indicator values and conversion

factors, thus reducing the amount of data entry and possi-

bility for errors. As already mentioned, indicator values are

bound to a certain process and conversion factors to the

products. Whenever a process or product is reused, every

use refers with a link to the original dataset. The idea

behind this is on the one hand to lessen the amount of work

needed for updates as a change is automatically perpetu-

ated to all usages, and on the other hand to keep a har-

monized dataset where the user can rely that a process will

be the same wherever it is used.

When creating a new chain, there are three options to

select from:

• To create a completely new FWC and topology where

new processes and products are defined and the

linkages between the processes are inserted from

scratch. Already existing processes and products, which

fit to the new application, can be reused. Moreover,

existing processes could be adjusted by creating a look-

alike copy of the process (the products of the copied

process remain the same, indicators and other process

attributes can be modified).

• To copy an existing topology into a new chain with

links to the existing processes. This generates a

duplicate of an existing FWC, with all its processes

and products. Some processes and products could be

replaced and/or the material flow manipulated by

modifying product shares or split ratios.

• To copy an existing topology into a new chain where

new processes and country specifications are created

(look-alike copy). Unlike in the previous option, the

new FWC processes are decoupled from the original

FWC, and all values can be edited without affecting

the data of the original source FWC. The entire

topology and the products of processes are initially

identical and can then be modified as required in the

new chain.

Links that connect processes can be drawn manually in

the chain editor. To handle huge chains, links can be

imported using a file that lists the source processes, the

target processes and the products to be connected. Products

can be added or deleted from processes at any time.

Table 1 Example of an indicator calculation in ToSIA; process:

transportation of pellets, indicator: labour cost, the material flow

assumed is 10 t of pellets

Process unit t (pellets)

Indicator unit €

Labour cost per t of pellets transported 2.7€/t

Calculated material flow of process 10 t

ToSIA indicator calculation 10 t 9 2.7€/t = 27€

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Once a topology is created, the data can be entered.

Table 2 states the data required to describe an FWC in this

approach.

Indicator values, process attributes and conversion fac-

tors can be collected or derived from various sources, e.g.

from statistic data (Eurostat, Comtrade, FAO statistics) or

computer models (e.g. forest growth, wood allocation or

transport models). If more accurate information is not

available, expert judgments can be used to fill the gaps. In

the EFORWOOD project, data collection protocols were

developed to provide clear guidelines, which help define

the indicators used and give examples on how the data

should be calculated (Berg 2008). Meta-data information is

also entered to provide the user with information about the

scope and reliability of the information used in calculation

of the results.

Material flow calculations in ToSIA

The material amounts in an FWC can be calculated in two

different directions by using different types of product

shares that characterize each process (see Fig. 2). The

output shares divide the material flows when calculating

from the forest management downward. The input shares

are utilized when moving upstream from the consumption

to the forest management.

In order to start a ToSIA calculation, a chain needs to be

initialized. As almost all the data collected is relative, the

FWC is given a concrete amount which is then used as the

basis for calculating the material flows throughout the

entire chain. In a forest- and region-defined application

study, the material flows are typically initialized in the

forest management processes, based on forest inventory

data. The initialization in this case is the actual hectares in

forest resource management processes, and using the

product output shares the concrete harvest volumes and the

industrial production amounts are calculated all the way to

the amount of waste left over when the material can no

longer be recycled. In a similar way, a consumption-

defined case can be initialized by giving the amount of

products consumed in a certain geographical area. The

third case is when the chain is initialized from the middle

in industry-defined cases. In this case, the production

capacity of the industry unit or sector is given as the ini-

tialization amount. ToSIA calculates from here both

upstream and downstream to obtain the required resource

amounts needed by the industry and the resulting produc-

tion amounts of consumer goods.

Related to these cases and to the design of a chain,

product trade (exports or imports) might need to be

included in the design of a chain in order to be able to make

a proper analysis of an FWC. When calculating a forest-

defined FWC, the imports of wood products from outside

of the defined FWC need to be initialized as well, as these

are coming from outside the system boundaries of the

currently analysed chain. Likewise, when looking at a

consumption-defined chain, the export amounts need to be

initialized, if a realistic view of the forest-based resource

Table 2 Core components of the topology of an FWC and its attributes

Components Attributes Definition/example

Process Name, time, description, assumptions,

geo-information, contact person

Basic information on the process and the year/scenario the data is applicable for

Process unit All indicator data and conversion factors refer to the unit stated here, e.g. m3, t, ha or t

of carbon

Shares of input and output products Needed to calculate the distribution of the material flow amongst the products. The

shares always refer to the total carbon flow

Indicator data Data is process-specific, the basis is always the total input material flow, given per

process unit; e.g. labour costs—€/m3

Conversion factor to EURO Data process-specific, monetary value of the product at the production stage

Product Conversion factors: Needed to convert material flow into different units; conversion factors to ha are only

required in the forest management part of the FWC; the conversion factor to ton of

carbon is always requiredProduct unit to ha

Product unit to m3

Product unit to t

Product unit to t of C

Product assumptions Basic information on the product, e.g. tree species, moisture content

Link Split ratios Defines how the material flow is divided, if one product is linked to many products/

processes or vice versaOne to many

Many to one

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production in source countries and the actual production

capacities of the industry are desired.

A detailed illustration of the method is given in the next

section.

A sustainability impact assessment example

In order to illustrate the method, an example is used to

explain the different steps involved in conducting a sus-

tainability impact assessment with ToSIA: (1) study

design, (2) FWC structure specification, (3) material flow

calculation, (4) indicator calculation, (5) FWC comparison

(Lindner et al. 2010). A sixth step may consist of an

evaluation and ranking of the FWC alternatives (cf.

Wolfslehner et al. 2008).

The example compares two alternative forest bio-energy

utilization chains in Eastern Finland, representing small-

and medium-scale district heating plants using woody

biomass from alternative supply chains. More context

about conducting a sustainability impact assessment of

alternative bio-energy supply chains can be found in

Werhahn-Mees et al. (2010).

Study design: The research question was how small-

and medium-scale bio-energy supply chains affect eco-

nomic, social and environmental sustainability in the rural

regions of Eastern Finland. Varying impacts were expected

due to differences in harvest and transport technology as

well as case-specific procurement distances. In the small-

scale supply chain in Tuupovaara, the harvesting is done

manually, and the energy wood supply is procured within a

close proximity to the district heating plant. In the medium-

scale supply chain in Outokumpu, the harvesting is

mechanized and transport distances are longer.

FWC structure specification: Figure 3 shows the two

alternative FWC topologies.

Material flow calculation: The basis of the material flow

calculation was the annually used amounts of forest chips

in the DHP:s. It is notable, that the wood material changes

its form many times between the processes in the supply

chains. A set of conversion factors were calculated to

control the effect of changes in form and moisture content

of the wood material. Since in these chains the wood

material is chipped and combusted, the conversion factors

between the whole wood and chipped wood and the heat

produced in the combustion process present the most

important conversions. Examples of conversion factors are

listed in the Table 3.

Indicator calculation: A set of indicators were defined

to quantify the sustainability impacts of the supply chains.

Production costs, greenhouse gas emissions from machin-

ery and employment were chosen based on stakeholders’

interests and data availability. Indicator data has been

partly provided by the stakeholders, complemented with

information from statistics, research reports and regional

calculation models.

FWC comparison: Figure 4 illustrates the results of the

chosen indicators. Indicator results were summed up along

the FWC and then divided by the material flow at the end

of the FWC (i.e. the amount of heat produced annually).

The mechanized medium-scale supply chain was more

favourable in terms of cost effectiveness, whereas the

small-scale supply chain showed lower fossil greenhouse

Fig. 2 Illustration of the

material flow calculation in

ToSIA using input and output

product shares and split ratios.

Input and output product shares

for one process add up to 100%.

Split ratios divide the product

flow to multiple processes

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gas emissions from machinery and a higher employment

effect. How these different sustainability impacts might be

evaluated depends on the weight that different stakeholders

put in favour of the small-scale supply chain. We conclude

that with these indicator results, it is not possible to define

unambiguously which one of the studied chains is more

sustainable. Straightforward ranking of the alternatives

would require further processing the results with multi

criteria analysis.

Application cases

ToSIA applications address specific questions and for that

clear system boundaries are required (Lindner et al. 2010).

These can be specified in different ways for forest-defined,

industry-defined, consumption-defined and region-defined

applications as described below. In addition, the scale of

applications can also vary a lot from a local scale to the

regional and continental scale (Table 4).

Except for the industry-defined case study, all other

cases where developed and tested within the EFORWOOD

project. The approach taken in the EFORWOOD case

studies has similarities in the set-up. As a baseline for all

cases, the reference year 2005 was selected. Furthermore,

two reference futures were selected and described for 2015

and 2025, based on the scenarios A1 and B2 developed for

the IPCC reports (Nakicenovic and Swart 2000). On top of

each of the reference futures, selected scenarios were

added. In the following sections, we present the main

characteristics of the applications.

Scandinavian case study

The ‘‘Scandinavian case study’’ is forest-defined and aims

to describe the network of FWCs originating from the

forest resource of Vasterbotten county, Sweden. Wood

from forests in the area of Vasterbotten is followed along

the value chain from the resource to the end-users of the

wood products in Europe.

The case study represents the boreal European FWCs

characterized by stands dominated of pine (Pinus sylvestris

L.) or spruce (Picea abies (L.) Karst.), or of mixtures of the

two species with or without broadleaved species, most

commonly birch (Betula spp.). The forest area in the base

year 2005 was approximately 3 million ha, and that year

the amount of wood cut was 7.8 million m3 over bark.

The stands in the region are mainly even-aged, and the

dominating harvesting techniques include the highest-

developed technology available at present, i.e. harvesters

and forwarders. The dominating transport from the forests

to the industry is road transport using 60-t trucks. The main

wood industry products include saw logs, pulpwood and

fuel wood from pine, spruce and birch, forest wood chips,

and stumps. The main industries are sawmills, Kraft pulp

mill, fine paper mill and combined heat and power plants.

Fig. 3 Illustration of the topologies of the two compared FWCs.

a The FWC of small-scale forest chip supply chain. The whole trees

are manually harvested from young stands and forwarded to roadside

with farm tractor and trailer. At the roadside, the whole trees are

chipped and then transported to the small-scale district heating plant

where chips are combusted to produce energy. b In the medium-scale

supply chain, the harvesting and forwarding is done mechanically

with harvesters and forwarders. The supply chain includes the

harvesting of whole trees from young stands as well as collecting

harvest residues from final felling. The chipping and transport

equipment is heavier, and the transport distance longer. Forest chips

are combusted in a medium-scale district heating plant

Table 3 Conversion factors for two main types of woody biomass used as fuel in district heating plants in Eastern Finland

Type of wood biomass Moisture

content (%)

Net calorific value

as received (Gj/t)

Weight (ton) Tons of C

1 m3 of whole tree chips 45–55 7–10 0.25–0.35 0.069

1 m3 of harvest residue chips 50–60 6–9 0.25–0.4 0.062

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In the study, model mills instead of real mills have been

used for calculations. The produced goods include e.g.

edge-glued panels, wood furniture, pellets and bio-energy.

The Swedish forest industry is very much depended on

markets outside Scandinavia. Therefore, included in the

case study are the exports of wood products to the Central-

and South-European markets as it is illustrated in Fig. 5.

The key research question answered in this case study

was to assess the impacts of changes in the sawmilling

technology on sustainability. The impact of the scenario on

the indicators such as gross value added (GVA), production

cost, employment and greenhouse gas emissions was

analysed.

Industry-defined case study

The industry-defined case study was not implemented in

the EFORWOOD project, but it is presented here as

another possible ToSIA application suitable for company

applications.

Fig. 4 Comparison of indicator

results for the small-scale

(Tuupovaara) and medium-scale

(Outokumpu) district heating

plants: a production costs (costs

are presented with and without

state-granted subsidies for

energy wood harvesting,

forwarding and chipping);

b greenhouse gas emissions

from machinery; c employment

(person years in full-time

equivalent)

Table 4 Overview of the application cases presented in this study

Cases Attributes

Perspective Geographical scope Characteristic Scenario analysis

Scandinavian

case study

Forest-

defined

Vasterbotten

(Sweden)

connected with the

rest of Europe

Wood from forests in Vasterbotten region is followed

along the value chain from the resource to the end-

users of the wood products in Europe.

Sustainability impacts of

technology improvement in

sawmills

Industry case

study

Industry-

defined

Resource use and

product distribution

are case-specific

Forest resources used by the industry and major

distribution channels of the products are

considered.

Company assesses the sustainability of its activities

for reporting on Corporate Social Responsibility.

Annual sustainability reporting;

impact of technology changes on

sustainability

Iberian case

study

Consumer-

defined

Iberian Peninsula

connected with

European wood

supply

Wood products consumed in Iberia are followed

backwards to the forest resources, including wood

supply from e.g. South-West France and

Scandinavia.

Sustainability impacts of changes

in paper consumption

Scottish case

study

Local Southern Scotland Harvested timber within the Craik case study forest is

allocated to alternative transport logistics under

scenarios of changed product proportions

Assessing impacts of changes in

timber allocation and transport

distances on key indicators

Baden-

Wurttemberg

case study

Region-

defined

Baden-Wurttemberg

(Germany)

All major FWCs within the region are analysed.

Imports and exports are considered to/from the

border of Baden-Wurttemberg.

Impacts of bio-energy policies on

sustainability of regional FWC

EU FWC Continental

(region-

defined)

EU 25 ? 2

(Switzerland and

Norway)

FWCs described at country level.

Trade flows of wood and wood products within

Europe included.

Imports and exports are considered to/from the EU

border.

Natura 2000—increased nature

conservation

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In the centre of the SIA could be either an industry

branch, e.g. the paper or sawing industry, or a single factory.

Starting from the industry, the FWC is modelled in both

directions: following the resource supply chain up streams to

the forest management, as well as down streams along the

value chains until the end of the wood product’s life cycle

with e.g. recycling or incineration of the wood product. This

might include transportation of products to markets in dif-

ferent countries and the imports of wood resources from

abroad, depending on the scope of the study (Fig. 6).

A possible scenario for analysis might be to assess the

impacts of changes in the production technology or to

monitor the changes in sustainability impacts of the

industry through time as a basis for reports on the sus-

tainability of the production practice.

The aim of such a case study is to show the current

impacts on sustainability of a certain production system

and to demonstrate how the overall situation can be

improved. Furthermore, hot spots of the FWC can be

identified. Companies can use the results of the assess-

ments for their Corporate Social Responsibility reporting to

document sustainability of its activities.

Iberian case study

The Iberian Case Study is consumer-defined and describes

FWCs feeding the Iberian market (i.e. Spain and Portugal)

with wood-based products. A major characteristic of the

Iberian wood product market are its large imports of wood

products from Scandinavia, France and Germany as illus-

trated in Fig. 7. Hence, market-driven effects on sustain-

ability are important. The case study focused only on a

limited number of final products consumed by the end-

users in Iberia, with main emphasis on paper and packaging

products. The FWC topology was developed in a backward

process, linking the consumption of selected final products

with the production of intermediate products, following the

underlying industrial processes up-chain to their forest

Fig. 5 Illustration of the geographical set-up of the Scandinavian

case study; the arrows symbolize the exports from the forest industry

in Vasterbotten, Sweden to Central and Southern Europe

Fig. 6 Illustration of an industry-defined case study, in the focus of

this application is a certain industry that receives wood as input and

sells products to consumer markets

Fig. 7 Illustration of the geographical set-up of the Iberian case

study, the arrows represent imports of wood products to the Iberian

market

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resource supply. The scenario analysed was a sustainability

impact assessment of changes in the paper consumption on

the Iberian Peninsula.

Scottish case study

This local forest-defined case study is focused on Craik

Forest in the Scottish Borders district, about 40 miles south

of Edinburgh (Fig. 8). Craik Forest is approximately

4,700 ha in size and is predominately Sitka spruce (Picea

sitchensis (Bong.) and Carr.). It produces significant

amounts of high-value timber and is located within 300 km

of 11 sawmills. The objective of the case study is to ana-

lyse the current management operations as well as the

timber products created from Craik Forest stands, and then

to make modifications to the allocation system. Under-

standing the effects of different methods of allocation is

imperative as how the timber is cut and to which sawmill

harvested material is sent to have a significant impact on a

variety of sustainability indicators.

A production forecast was developed for all forest

stands within Craik Forest and projected harvest details

(thinnings and final fellings) were assimilated between

2005 and 2030 and included in the simulation. A product

allocation model has been developed and is utilized when

comparing different log breakout scenarios. Utilizing tree

growth and wood properties models, log product propor-

tions and volume calculations were made for forest prod-

ucts (structural timber, pallet wood, and biomass) using

different allocation strategies. The impacts of the alterna-

tive allocation scenarios have been measured using four

key indicators: gross value added (GVA), transport dis-

tance, greenhouse gas emissions, and employment.

The allocation analysis aimed to achieve an optimal

range of products per tree while simultaneously satisfying

market demand. This local case study represents a good

example for the comparison of technology alternatives and

how they affect key sustainability indicators.

Baden-Wurttemberg case study

This case study is regional defined and aims to describe the

network of FWCs in Baden-Wurttemberg including timber

and product imports into the region and exports out of the

region and cross-links between the different production

lines of sawmilling, pulp & paper and the bio-energy sector

(Fig. 9). The case study area represents the ‘‘Central-

European region’’ characterized by heterogeneous hard-

wood and softwood forests in terms of species mixture and

age distribution and a highly diversified wood industry.

For the case study, only the tree species Norway spruce

(Picea abies (L.) Karst.) and European beech (Fagus

sylvatica L.) were considered as they account for more than

2/3 of the wood volume produced in Baden-Wurttemberg.

The main wood industry sectors present in Baden-Wurt-

temberg are sawmilling, pulp and paper production, panel

production, bio-energy and successive (e.g. woodworking)

industries. Altogether 60–80% of the natural production in

the forests, of primary and secondary processing in the

wood industry, i.e. wooden products, paper and boards,

panels and bio-energy, and of the consumption of the

produced goods was described. End of life options of the

Fig. 8 Illustration of the Scottish case study, analysed is a small-

scale local FWC in the Craik region, South Scotland

Fig. 9 Illustration of the Baden-Wurttemberg case study, exports and

imports in the region are considered in the material flow calculation in

the FWC, but excluded from the sustainability indicator assessment

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consumed goods were incineration and recycling with feed

back into the material flow.

The main focus of the case study was the assessment of

impacts of bio-energy policies on the overall sustainability

of the regional FWC.

EU forest-wood chain

The EU-FWC is the widest application undertaken within

the EFORWOOD project. This application aims to describe

the major FWCs at the European level.

The basic approach in the EU-FWC is that:

• FWC topology is described at country level, but groups

of countries (Northern EU, Southern EU, Eastern EU

and Central/Western EU) have similar chain topology

• Volume flows are assessed at the country level;

processes may have zero-volume flow if that process

is not relevant in the country.

• Indicators are given for processes in countries. Indica-

tors within country groups may have the same value.

The system boundaries of the EU FWC are the geo-

graphical boarders of the European Union. The trade flows

of round-wood and wood products within Europe are

included. Trade with countries outside the European Union

is only quantified at the system boundaries but not included

in the sustainability impact analysis (Fig. 10). The topol-

ogy development process has started by creating templates

of production systems for country groups representing

typical forest value chains that are similar for neighbouring

countries. These templates were combined and copied to

describe FWCs in 25 European countries (EU25 plus

Norway and Switzerland; Malta was combined with Italy;

Greece and Cyprus were excluded from flow calculations

due to missing data). The forest management is described

by only one process for each country. The main research

question was to assess the effect of European conservation

policies on the overall sustainability of the European

forest-based sector. In particular, the impact of signifi-

cantly increasing Natura 2000 nature conservation areas in

European forests was assessed.

Discussion

The flexibility of the ToSIA approach allows applications

for quite different types of forest value chains. The speci-

fication of the FWC topology and all system boundaries

significantly affects what data need to be collected and at

which scale. In current times with intensive global trade

connections, most European FWCs are crossing country

borders. For example, Scandinavian countries are impor-

tant producers of wood products for European markets

(Swedish Forest Agency 2009). ToSIA was designed in a

way that allows different geographical references to be

used for parts of the value chains. While in forest-defined

applications, the geographical region of the forest resources

determines the amount of material flow included in the

calculation, the value chain connects these forest resources

with consumption that is taking place also outside of the

region. In the case of consumption-defined cases, it is the

opposite case and the consumption of wood products in a

target region specifies the amount of material flow that is

considered in the analysis. Due to the huge diversity of tree

species and wood products, it is hardly ever possible to

achieve 100% coverage of material flows in the forest-

based sector. Therefore, each application needs to carefully

study and analyse the FWC structure which should be

reflected in the topology and make decisions where to set

thresholds determining cut-offs from the system boundaries

and how to aggregate processes and products. This might

refer to minor tree species (e.g. the regional-defined Baden-

Wurttemberg case study focused only on two main tree

species) or to FWC branches with poor data availability

(e.g. it was found to be difficult to collect data on the

manufacturing and consumption of solid wood products).

When trade across country borders is considered, it might

also be practical to aggregate products to product groups

and to focus on a limited number of important countries for

the export or import connections.

The choice of scenarios is another important step in any

sustainability impact assessment. The ToSIA concept

allows specifying different FWC structures using alterna-

tive management strategies in the resource management,

establishment of industry plants of varying sizes and dif-

ferent technological options in the production chains. It is

also possible to study changes in external factors (e.g. the

global oil market price) affecting sustainability of existing

FWCs. Comparing the scenario results highlights impacts

of scenario alternatives on various sustainability indicators.

This could be of critical importance when creating a

Fig. 10 Illustration of the EU forestry wood chain, only exports and

imports within the EU25 plus Norway and Switzerland are included

in the FWC

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business plan or a regional development plan, exploring

new management techniques and justifying expenditure for

new technological innovations. Other potential applications

focus on ex-ante sustainability impact assessment of policy

options (cf. Tscherning et al. 2008). In those cases, the

same forest value chain is studied under different con-

straints or incentives imposed by alternative policy levels

or options.

The standard application of a SIA is the comparison of

FWC alternatives within one case study. In that case, the

system boundaries and external factors affecting sustain-

ability are the same, while only a limited number of factors

are altered and thus the sustainability impacts can be

directly attributed to the investigated scenario alternatives.

Comparing sustainability indicator results between differ-

ent case studies is not advocated, because results can be

misleading. Climate and site conditions greatly influence

forest productivity and also silvicultural systems vary a lot

for example between Norway spruce management systems

in Northern Sweden and Baden-Wurttemberg. Therefore,

sustainability indicator values differ enormously between

the case studies, but it is impossible to identify a cause–

effect relationship. When indicator values are related to

comparable amounts of products produced, it is neverthe-

less informative to compare e.g. the employment effects,

production costs and environmental impacts between sys-

tems. But this type of comparison should not target the

sustainability impacts of the production, because both

productive and less productive systems can be managed

with poor or good sustainability impacts.

The current implementation of the ToSIA approach is

limited to the forest-based sector. The system boundaries

(e.g. to which extent imports and exports are considered)

can be selected by the user of the tool, as long as the

assumptions are clearly stated. Depending on the set-up of

the study, the consequences for the interpretation of the

results have to be carefully kept in mind.

ToSIA does not assess sustainability thresholds, as these

are difficult to be specified for many relevant sustainability

indicators (Haberl et al. 2004; Lindner et al. 2010). ToSIA

focuses on the impacts of change (e.g. a change of a pro-

duction technology) on sustainability. The interpretation of

the results has to be conducted by the user or researcher

with expert judgment or on the basis of adequate decision

support tools (e.g. Cost-Benefit Analysis, Multi Criteria

Analysis). Such tools were also developed within in the

EFORWOOD project and integrated into ToSIA (Prokofi-

eva et al. 2010; Wolfslehner et al. 2011).

A core experience related to the data collection for the

case studies and the development of the ToSIA approach is

the importance of the data quality for the calculated results.

Mistakes in the design of the topology or missing data

make it impossible to run ToSIA correctly. The material

flow calculation in ToSIA is a crucial prerequisite for the

indicator calculation and requires high accuracy in the data

input. Inconsistency in the data will affect the results sig-

nificantly, and therefore carefully conducted data valida-

tion is important. Different validation systems were

introduced in ToSIA, and also the ToSIA input data was

independently verified. With increasing size and com-

plexity of case studies, automatic and standardized vali-

dation methods are getting more important. Several

routines have been embedded into the software to check the

completeness and consistency of data. For example, ToSIA

checks completeness of conversion factors and split ratios

to ensure consistent calculation of material flows. Incom-

plete data are printed in data reports. Experiences from the

case studies showed that the design phase of the assessment

is extremely important to identify suitable process aggre-

gations for the data collection. If data are unavailable for a

specific process, additional assumptions need to be made to

enable the calculation with ToSIA. Very crucial for a

successful sustainability impact assessment is the accurate

specification of indicator definitions and calculations in the

data collection protocol. With continuous development of

the methods in the EFORWOOD project, changes in data

requirements were sometimes unavoidable. But quite often

it was found that the first data collection protocols were not

unambiguous, and different interpretations by data pro-

viders resulted in inconsistencies. The revised EFOR-

WOOD data collection protocols were designed to support

future assessments with tested instructions for numerous

sustainability indicators.

The data collection undertaken in the EFORWOOD

project was enormous. The data amount created a great

challenge with regard to the data handling and verification.

Applications with the complexity of the EU FWC need a

careful planning on the capacities of the systems used.

The preferred source of data input for the EFORWOOD

cases was official statistics. Within the chosen system

boundaries of the different cases, however, official statis-

tics were not always available. This concerned both data on

flow quantification and indicator values in different stages

of the FWCs. In such cases, assumptions had to be made,

and these need to be clearly stated. For example, it was

difficult to quantify consumption of wooden goods and

wood-based products for Baden-Wurttemberg. The con-

sumption was finally estimated from statistical data for

Germany broken down per capita for Baden-Wurttemberg.

Another difficulty was the calculation of trade flows for

round wood, semi-finished products and end-products

between Baden-Wurttemberg and the other 16 federal

states in Germany; also European and overseas imports and

exports could only be quantified on an overall national

basis. To overcome this problem, volumes of material in

each category were handled as net-balance derived from

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known volumes produced and consumed in Baden-Wurt-

temberg. From that difference, net-trade flows of wood

volume were calculated. It is important to document such

assumptions and approaches in the complementary

description of the particular case study. The problems with

data accessibility for sustainability indicators in certain

parts of the forest-based sector suggest that better statistical

data is needed, if SIA should be applied more regularly in

the ex-ante policy evaluation process (Tscherning et al.

2008).

In all case studies, simplifications were needed to

implement the SIA. In the Scandinavian case study, the

target was set that at least 70% of the material flow orig-

inating from wood cut in the Vasterbotten region should be

followed downstream the FWC. It was decided to cover

these product trade flows by products exported to Germany

(representing 64% of total deliveries from Vasterbotten to

Western/Northern Europe) and Spain (representing 10% of

total deliveries from Vasterbotten to Southern Europe).

Linkages between trade of specific products were very

complex in the EU case and solved by introducing a con-

cept of import–export-buckets for the six main product

groups (roundwood, pulp, paper/board, primary conversion

products, secondary conversion products, bio-energy)

which gather and redistribute all EU-trade flows (and

imports from outside European Union) of these product

groups.

A common difficulty was that industry data is often

confidential and that information from individual mills

should not be recognizable from the data. To avoid confi-

dentiality problems, it was decided to use generic mill-type

data in the EFORWOOD case studies, representing typical

mill characteristics for groups of neighbouring countries.

However, it turned out to be difficult to calculate average

indicator values for the mill categories, as this requires

more data than typically available from individual test

cases.

The scenarios illustrated in the Scottish case study were

for demonstrative purposes only as they were simplified

relative to actual operations and actual values. However,

the study was able to show how it is possible to calculate

sustainability indicators for the forest-based sector which

can be further assessed and interpreted by the end-user.

Additional work on the structure of the FWC and on data

refinement is required as a follow-up to bring the case

study closer in line to actual operational procedures. In

particular, performing a sensitivity analysis on existing

scenarios, making scenarios more realistic, and using

actual data instead of modelled data would increase the

relevance of the results for local stakeholders.

Current ToSIA applications are limited to the forest-

based sector, and impacts on the overall sustainability of

production of non-wood materials used in wood products

FWC (e.g. metal and plastics used in furniture) are not

taken into consideration. The limitation of the ToSIA

system boundaries to the forest-based sector is not a con-

ceptual decision, but it was due to limited resources in

EFORWOOD and the wish to establish the method for one

sector. It is foreseen to apply the method also to other

materials and value chains in the future.

Another limitation in the current applications of ToSIA

is the geographical system boundary at the import/export

harbours of Europe. Sustainability impacts of the imports

of wood products (‘‘sustainability backpack’’) from outside

of Europe are not considered. Consequently, the global

sustainability impact (cf. (Cruz and Boehe 2008) could be

deviating significantly from the results calculated by

ToSIA within the current system boundaries. Applying the

approach to globally important forest resources and inter-

national trade will be a crucial step forward to allow

assessment of substitution effects on sustainability, for

example if European pulp production is more and more

replaced by imported pulp and paper from South America

(cf. Barnden 2007). The current implementation of ToSIA

takes an attributional approach (i.e. attributing sustain-

ability impacts to processes of specific FWCs), while in

principle, data availability assumed, the system boundaries

could be expanded to allow for a consequential approach as

well (i.e. analysing sustainability impacts in the FWC

processes as well as in the consequent changes outside of

the studied FWC). The development of life cycle analysis

(LCA) methods has also shown that with increasing data

becoming available, the focus was shifting from attribu-

tional to consequential LCA approaches with a subsequent

expansion of system boundaries (Finnveden et al. 2009). A

pragmatic short-term solution could be to link global eco-

logical footprint indicators into the ToSIA framework for

those environmental impacts that have already been

assessed with LCA e.g. (Dias et al. 2007; Gonzalez-Garcıa

et al. 2009) or ecological footprint assessments (Nie et al.

2010; Wackernagel and Rees 1996). However, it would be

important to cover also social and economic aspects of

global forest resource use and subsequent FWCs (Charnley

2006).

One of the major strengths of ToSIA compared to other

existing sustainability assessment methods (Ness et al.

2007) is that the tool allows quantifying a broad range of

indicators of sustainability, whereas LCA is usually

assessing only few environmental impacts. ToSIA inte-

grates indicators for environmental, social and economic

sustainability, and the assessment framework is very flex-

ible to use almost any indicator that can be quantified and

related to the material flow in production processes. The

advantage over input–output accounting models (Wied-

mann et al. 2007) is the possibility to project future sus-

tainability performance and to vary the aggregation level of

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production processes within the forest-based sector, which

facilitates the comparison of technology alternatives within

the sector.

Considerable efforts were invested by many researchers

in EFORWOOD to collect sustainability indicators for the

case study FWCs. How much effort will it take in the

future to set up new sustainability impact assessment with

ToSIA? ToSIA and the EFORWOOD database were

designed to support the reuse of FWC elements such as

production processes in new FWC applications. For

example in the European FWC case study, FWC topologies

were first specified for country groups with similar char-

acteristics in the forest value chains and then copied to the

individual countries. With this approach, it is possible to

reduce the data needs as one process carries identical

indicator values in all copies of this process. At the same

time, it is easy to alter differing values and topologies

without needing to start designing topology and entering

same data from scratch. The main adaptation required in a

new FWC context concerns the material flow parameters,

because different countries often vary in the relative

amounts of material flow in different FWC branches. With

the development of the method, products were also

assigned specific properties that are the same in different

locations of the FWC. This change compared to earlier

development stages facilitates data collection in large FWC

assessments and will reduce the demand for new data

collection in new applications as many product character-

istics such as conversion factors will remain constant.

All FWCs included in EFORWOOD case studies repre-

sent typical value chains as they are common across Europe

at present. For new local case studies, it is possible to copy

suitable FWC topologies from the existing data and then to

adapt them to the new local conditions for example by

adjusting specific process assumptions and replacing the

associated indicator values with measured data that are more

accurately characterizing the local case. To make use of

existing inventories and databases, it is generally possible to

modify also the indicator definitions. However, we advocate

following as close as possible the EFORWOOD data col-

lection protocols, as this allows comparing the local indi-

cator values with reference data from previous applications.

Conclusions

Conducting sustainability impact assessment for a com-

plete industrial sector is challenging, as there are many

different value chains with complex interactions, which are

often expanding beyond local and regional case study

boundaries. Furthermore, as the required industry data is

often confidential, generic mill-type data was used in the

EFORWOOD case studies, but those were not easy to

collect. Due to the complexity of the SIA, for all case

studies clear system boundaries have to be defined. Sim-

plifications are inevitable, and ToSIA offers a transparent

approach to document assumptions and to represent most

relevant FWC processes and their impacts on sustainability

indicators, spanning complete forest value chains from

regeneration to end of life of wood products. ToSIA

proofed to be a suitable tool for simulations of different

scenarios in the forest wood sector, specified as alternative

FWC structures with their relative impacts on sustainabil-

ity. Various assumptions can be applied and combined in

multiple comparisons of projected sustainability impacts.

The topology settings need to be well defined, and all

assumptions clearly documented. These are important for

proper interpretation of results.

Current data limitations do not allow expanding system

boundaries to include possible global substitution effects of

changes in the forest-based sector in Europe. Similarly,

sustainability impacts of using more or less competing

materials from other sectors are also currently excluded

from the assessment. These two aspects should be focus of

further development of ToSIA applications.

The flexibility of the SIA approach allows assessing

many different regional sustainability questions in the

forest-based sector. Depending on the research question,

different indicators can be adopted, not only from the

EFORWOOD indicator framework. Besides ToSIA and the

underlying development of the sustainability impact

assessment methodology, the EFORWOOD database of

FWC processes, products and sustainability indicator val-

ues for different case studies represents on its own a major

achievement of the EFORWOOD project. It will serve as

indispensable reference for future sustainability impact

assessments in the European forest-based sector.

Acknowledgments This work was funded by the European Com-

mission (FP6) through the EFORWOOD project (Project no. 518128).

We would like to thank numerous project partners for the fruitful

cooperation in the different ToSIA applications. A large number of

EFORWOOD experts contributed in different ways to the work out-

lined in this study.

References

Barnden R (2007) Pulp production in the Americas—all eyes move

South. Paper Age 123:24–28

Berg S (ed) (2008) EFORWOOD Deliverable PD0.0.16: manual for

data collection for Regional and European cases—UPDATE, 3

Sep 2008. Skogforsk, Uppsala

Burke L, Logsdon JM (1996) How corporate social responsibility

pays off. Long Range Plan 29:495–502

Charnley S (2006) Industrial plantation forestry: do local communi-

ties benefit? J Sustain For 21:35–57

Cruz LB, Boehe DM (2008) CSR in the global marketplace: towards

sustainable global value chains. Manage Decis 46:1187–1209

Eur J Forest Res (2012) 131:21–34 33

123

Author's personal copy

Dias AC, Arroja L, Capela I (2007) Life cycle assessment of printing

and writing paper produced in Portugal. Int J Life Cyle Assess

12:521–528

Finnveden G, Hauschild MZ, Ekvall T, Guinee J, Heijungs R,

Hellweg S, Koehler A, Pennington D, Suh S (2009) Recent

developments in life cycle assessment. J Environ Manage

91:1–21

Gonzalez-Garcıa S, Berg S, Feijoo G, Moreira MT (2009) Environ-

mental impacts of forest production and supply of pulpwood:

Spanish and Swedish case studies. Int J Life Cycle Assess

14:340–353

Guinee J (ed) (2002) Handbook on life cycle assessment—operational

guide to the ISO standards. Kluwer Academic Publishers,

Dordrecht

Haberl H, Fischer-Kowalski M, Krausmann F, Weisz H, Winiwarter V

(2004) Progress towards sustainability? What the conceptual

framework of material and energy flow accounting (MEFA) can

offer. Land Use Policy 21:199–213

Lindner M, Suominen T, Palosuo T, Garcia-Gonzales J, Verweij P,

Zudin S, Paivinen R (2010) ToSIA—A tool for sustainability

impact assessment of forest-wood-chains. Ecol Model 221:

2197–2205

Nakicenovic N, Swart R (eds) (2000) Special report on emissions

scenarios. Cambridge University Press, Cambridge, UK

Ness B, Urbel-Piirsalu E, Anderberg S, Olsson L (2007) Categorising

tools for sustainability assessment. Ecol Econ 60:498–508

Nie Y, Ji C, Yang H (2010) The forest ecological footprint

distribution of Chinese log imports. For Policy Econ 12:231–235

Paivinen R, Lindner M (2008) Assessment of sustainability of forest-

wood chains. In: Cesaro L, Gatto P, Pettenella D (eds) The

multifunctional role of forests—policies, methods and case

studies. EFI Proceedings 55. European Forest Institute, Joensuu,

pp 153–160

Paivinen R, Lindner M, Rosen K, Lexer MJ (2011) A concept for

assessing sustainability impacts of forestry-wood chains. Eur

J For Res. doi:10.1007/s10342-010-0446-4

Prokofieva I, Lucas B, Thorsen BJ, Carlsen K (2010) Deliverable

D1.5.6. Monetary values of environmental and social external-

ities for the purpose of cost-benefit analysis in the EFORWOOD

project. EFORWOOD deliverable report. Forest Technological

Center of Catalonia (CTFC), Solsona

Swedish Forest Agency (2009) Swedish statistical yearbook of

forestry 2009. Skogsstyrelsen, Jonkoping

Tscherning K, Konig B, Schoßer B, Helming K, Sieber S (2008)

Ex-ante impact assessments (IA) in the European commission—

an overview. In: Helming K, Perez-Soba M, Tabbush P (eds)

Sustainability impact assessment of land use changes. Springer,

Berlin, pp 17–33

Uthes S, Fricke K, Konig H, Zander P, van Ittersum M, Sieber S,

Helming K, Piorr A, Muller K (2010) Policy relevance of three

integrated assessment tools—a comparison with specific refer-

ence to agricultural policies. Ecol Model 221:2136–2152. doi:

10.1016/j.ecolmodel.2009.08.010

Wackernagel M, Rees W (1996) Our ecological footprint: reducing

human impact on the earth. New Society Publishers, Gabriola

Island

Walter C, Stutzel H (2009) A new method for assessing the

sustainability of land-use systems (II): Evaluating impact

indicators. Ecol Econ 68:1288–1300

Weaver PM, Jordan A (2008) What roles are there for sustainability

assessment in the policy process? Int J Innov Sustain Dev 3:9–32

Wenzel H (1998) Application dependency of LCA methodology: key

variables and their mode of influencing the method. Int J Life

Cycle Assess 3:281–288

Werhahn-Mees W, Garcia-Gonzalo J, Palosuo T, Roser D, Lindner M

(2010) Sustainability impact assessment of increasing resource

use intensity in forest bioenergy production chains. Glob.

Change Biol Bioenergy. doi:10.1111/j.1757-1707.2010.01068.x

Wiedmann T, Lenzen M, Turner K, Barrett J (2007) Examining the

global environmental impact of regional consumption activi-

ties—Part 2: review of input-output models for the assessment of

environmental impacts embodied in trade. Ecol Econ 61:15–26

Wolfslehner B, Lexer MJ, Rammer W, Becker G, Votter D, Bolle V,

Bruchert F (2008) Evaluierung der Nachhaltigkeit von Wald-

Holz-Ketten. AFZ-Der Wald 63:469–471

Wolfslehner B, Bruchert F, Fischbach J, Rammer W, Becker G,

Lindner M, Lexer MJ (2011) Exploratory multi-criteria analysis

in sustainability impact assessment of forest-wood chains: the

example of a regional case study in Baden–Wurttemberg. Eur

J For Res. doi:10.1007/s10342-011-0499-z

34 Eur J Forest Res (2012) 131:21–34

123

Author's personal copy