Quantification and valuation of ecosystem servicesin diverse production systems for informeddecision-making

Bhim Bahadur Ghaley a,*, Lars Vesterdal b, John Roy Porter a

aDepartment of Plant and Environmental Sciences, University of Copenhagen, Højbakkegard Alle 30,

DK-2630 Taastrup, DenmarkbDepartment of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23,

DK-1958 Frederiksberg C, Denmark

e n v i r o n m e n t a l s c i e n c e & p o l i c y 3 9 ( 2 0 1 4 ) 1 3 9 – 1 4 9

a r t i c l e i n f o

Article history:

Received 21 September 2012

Received in revised form

29 July 2013

Accepted 5 August 2013

Available online 27 September 2013

Keywords:

Bio-physical quantification

Combined food and energy system

Economic valuation field

measurements

Land management

Marketable and non-marketable

ecosystem services

a b s t r a c t

The empirical evidence of decline in ecosystem services (ES) over the last century has

reinforced the call for ES quantification, monitoring and valuation. Usually, only provision-

ing ES are marketable and accounted for, whereas regulating, supporting and cultural ES are

typically non-marketable and overlooked in connection with land-use or management

decisions. The objective of this study was to quantify and value total ES (marketable and

non-marketable) of diverse production systems and management intensities in Denmark to

provide a basis for decisions based on economic values. The production systems were

conventional wheat (Cwheat), a combined food and energy (CFE) production system and

beech forest. Marketable (provisioning ES) and non-marketable ES (supporting, regulating

and cultural) ES were quantified by dedicated on-site field measurements supplemented by

literature data. The value of total ES was highest in CFE (US$ 3142 ha�1 yr�1) followed by

Cwheat (US$ 2767 ha�1 yr�1) and beech forest (US$ 2328 ha�1 yr�1). As the production system

shifted from Cwheat - CFE–beech, the marketable ES share decreased from 88% to 75% in CFE

and 55% in beech whereas the non-marketable ES share increased to 12%, 25% and 45% of

total ES in Cwheat, CFE and beech respectively, demonstrating production system and

management effects on ES values. Total ES valuation, disintegrated into marketable and

non-marketable share is a potential way forward to value ES and ‘tune’ our production

systems for enhanced ES provision. Such monetary valuation can be used by policy makers

and land managers as a tool to assess ES value and monitor the sustained flow of ES. The

application of ES-based valuation for land management can enhance ES provision for

maintaining the productive capacity of the land without depending on the external fos-

sil-based fertilizer and chemical input.

# 2013 Elsevier Ltd. All rights reserved.

Available online at www.sciencedirect.com

journal homepage: www.elsevier.com/locate/envsci

1. Introduction

Ecosystem services (ES), classified as provisioning, regulating,

supporting and cultural ES are inevitable for the socio-economic

well-being of the mankind (UKNEA, 2011). Provisioning ES

* Corresponding author. Tel.: +45 35 33 3570; fax: +45 35 33 34 88.E-mail address: bbg@life.ku.dk (B.B. Ghaley).

1462-9011/$ – see front matter # 2013 Elsevier Ltd. All rights reservedhttp://dx.doi.org/10.1016/j.envsci.2013.08.004

includes food, fodder, fibre, timber, bio-energy; supporting ES

includes soil formation, nutrient cycling, primary production;

regulating ES includes hydrological flow, soil erosion preven-

tion, pollination, biological control of pests and disease, carbon

sequestration etc. and cultural ES includes recreation, educa-

tion, aesthetic value etc. (MEA, 2005). The unabated exploitation

.

e n v i r o n m e n t a l s c i e n c e & p o l i c y 3 9 ( 2 0 1 4 ) 1 3 9 – 1 4 9140

of the available natural resources to meet the food, fibre and

energy demands of the growing population have dwindled the

supply of ES to all-time low levels as illustrated by the

Millennium Ecosystem Assessment (MEA, 2005). With regard

to agricultural crop production, provisioning, regulating and

supporting ES are particularly important to maintain the

productive capacity of land due to the natural processes of

control of pest and disease, pollination, nutrient cycling, water

regulation, breakdown of toxic wastes and other associated ES.

As provisioning ES (food, fodder, timber, energy production) are

marketable, this has resulted in the unprecedented race in

production of marketable goods by application of chemical

inputs. This trend has led to a vicious cycle where more inputs

are required over the years to maintain the same level of

production, resulting in increased cost of production, adverse

environmental impacts (Pacini et al., 2003; Liu et al., 2012a) and

degradation of natural resources for provision of ES. The non-

marketable ES, upon which the very existence of marketable ES

hinges on, are considered as ‘free’ inputs from the nature and

continuously ‘mined’. Hence, there is a need to bring forth

significance of marketed (provisioning) and non-marketed ES

like regulating, supporting and cultural ES by assigning

economic values and recognizing their role in the productivity

of production systems.

As both marketable and non-marketable ES depends on the

management intensity and land-use, there is a need to take

these factors into account if rational decisions need to be

taken by land managers and policy makers through policy

instruments (von Haaren et al., 2012; Farley and Costanza,

2010; Daily et al., 2009). The existing policy instruments at

national and European Union scale like Environmental Action

Programme, Nitrate Directive, Water Framework Directive,

Post 2005 Common Agricultural Policy, Good Agricultural and

Environmental practices, cross compliance etc. (European

Commission, 2011) have been instrumental in mitigating the

continued deterioration of ES provision and the policies need

to be dynamic in order to meet its objectives under changing

socio-economic settings. Hence, economic values from con-

text-specific ES valuation can be fed into existing agri-

environmental policies to enhance the effectiveness of the

policies in place (European Commission, 2011; Tangermann

and Adinolfi, 2011) for ES provision. The monetisation of ES

have been reported at global scale (Costanza et al., 1997) as

well as at field scale (Sandhu et al., 2010b, 2008; Porter et al.,

2009; TEEB, 2010; Drake, 1992, 1999) under different contexts

(Banzhaf, 2010; Engle, 2011; Hao et al., 2012; Liu et al., 2012b;

Mendoza-Gonzalez et al., 2012). In some studies like combined

food and energy production systems (Porter et al., 2009), forest

(Niu et al., 2012) or grassland (Amiaud and Carrere, 2012), the

number of ES investigated were limited whereas in other

studies (Sandhu et al., 2008, 2010a,b), the range of production

systems investigated were limited (organic and conventional

production systems) and differences in ES valuation methods

in different production systems and sites are barriers in

across-the-site comparisons of ES values. We complement the

earlier studies with a consistent field experiment method in

production systems (cropland to beech forest) across a

spectrum of management intensity under same socio-eco-

nomic setting for biophysical quantification and assessment

of 15 ES. The segregation of total ES into marketable and

non-marketable ES across production systems can reveal the

impacts of different land use and management intensities on

the bundle of ES provision.

We chose production systems with different degrees of

human intervention ranging from intensively cultivated

conventional wheat to managed beech forest with the

expectation that the specific ES and the share of ES accruing

from these diverse ecosystems would vary drastically. Based

on the ES classification used by MEA (2005), the assessed ES

were (a) provisioning viz. food, fodder, bio-energy and wood

production, (b) regulating viz. water holding capacity, carbon

sequestration, soil erosion prevention, shelter belt effects,

nitrogen fixation, pollination and biological control of pests

and disease, (c) supporting viz. nutrient cycling and soil

formation and (d) cultural viz. aesthetic value. The objective of

the study was quantification and valuation of total ES

(marketable and non-marketable) in diverse production

systems and management intensities to provide an objective

basis for informed decision-making.

2. Materials and methods

2.1. Study sites

The study sites were located at two locations in eastern

Denmark: one in Taastrup and another in Frederiksborg close

to Hillerød. The trial site at Taastrup is an experimental farm

(558400 N, 128180 E) under the Department of Plant and

Environmental Sciences, whereas the Frederiksborg site

(558570 N, 128210 E) is a European beech (Fagus sylvatica L.)

forest, a long-term level II monitoring site under the

International Co-operative Programme on Assessment and

Monitoring of Air Pollution Effects on Forests (ICP Forests)

managed by Department of Geosciences and Natural Resource

Management, Faculty of Science, University of Copenhagen.

The forest site has been under beech forest since 1964 before

which annual crops were grown in the site.

At the Taastrup site, a combined food and energy

production system (CFE), and conventional wheat (Triticum

aestivum) (Cwheat) fields were located. CFE is laid out in

11.1 ha, consisting of food, fodder and bio-energy (shelter

belts) components and was established in 1995 and managed

without fertilizer and other chemical inputs until date. In CFE,

the food components consisted of winter wheat, barley

(Hordeum vulgare), oat (Avena sativa) and fodder component

consisted of ryegrass (Lolium perenne)/lucerne (Medicago sativa)

ley and bio-energy component consisted of 5 double rows of

short rotation woody crops (shelterbelts). Of 5 double rows, the

3 middle double rows consisted of three species (one double

row each) of willow (Salix viminalis (L.) ‘‘Jor’’, S. dasycladus

Wimmer and S. triandra � cinerea L.) bordered by one double

row of common hazel (Corylus avellana L.) on one side and one

double row of alder (Alnus glutinosa (L.) Gaertner) on the other

side. Prior to 1995, the site was continuously cropped with

annual crops. The Cwheat field was located adjacent to the CFE

and the field was cropped with winter wheat and fertilizer,

herbicide and pesticide inputs were applied according to the

standard practice in Denmark. The site has been cultivated

with annual cereal crops and grass for the last 15–20 years.

e n v i r o n m e n t a l s c i e n c e & p o l i c y 3 9 ( 2 0 1 4 ) 1 3 9 – 1 4 9 141

There were in total 7 production systems under study,

consisting of Cwheat, beech forest and the 5 production

systems embedded within CFE system viz. CFE wheat, CFE

ryegrass/lucerne ley, CFE oat, CFE barley and shelterbelt.

Based on a share of 24% acreage for each of CFE wheat, CFE

barley, CFE oat and CFE ryegrass/lucerne ley and 4% for

shelterbelt, parameters for CFEaverage were based on area-

weighted averages across the 5 production systems in CFE.

2.2. Field samplings and measurements

The field work started in March, 2011 and ended in February,

2012. All samplings consisted of 4 replicates in each

production system. During the experimental period, different

soil and plant measurements were carried out to assess

indicators/proxies of diverse ES. Details of methods for on-

site field measurements are provided in Table 1. Soil samples

consisted of 4 soil bulk samples, each composed of 5–6

subsamples, taken with a soil auger, to a depth of 25 cm. The

samples were then air-dried at room temperature (25 8C),

sieved and any stones or macroscopic materials larger than

2 mm were removed, followed by storage at �48 until the

analysis. Soils were analysed for total carbon and total

Table 1 – Overview of on-site field measurements of bio-phys

Ecosystem service Data required Sampling frequen

Provisioning

Food Crop yield Grain and straw yield

harvest in August

Fodder Sward yield 13th May

16th August

1 November

Bio-energy Shelterbelt biomass

yield

At harvest in Februar

Wood Beech wood yield

Regulating

Water holding

capacity

Soil moisture content

and bulk density

Soil fresh and dry we

in June

Carbon

sequestration

Above and

belowground

biomass

At harvest and literat

review

Supporting

Nitrogen

mineralisation

Bait lamina probe

feeding activity

10 days in June

Soil carbon and

nitrogen content

Soil samples taken in

Soil temperature

and moisture

Before and after bait

lamina feeding in Jun

Soil formation Earthworm count

and weight

June

nitrogen (modified Dumas method) with CHNS/O analyzer

(Flash 2000, Thermo Fisher Scientific, Cambridge, UK). Bulk

density and moisture content determination were based on 4

soil cores of 100 cm3 per treatment, taken with soil core

samplers, weighed, oven dried at 808 for 72 h and reweighed.

3. Bio-physical quantification and valuation ofES indicators

3.1. Provisioning services

The grain, straw, fodder and woodchip (shelter belts) yields are

the average annual values for the period 2002–2012 whereas

the beech forest yields are the annual average values for a full

rotation of 100 years. Food, fodder, woodchip yields were

determined at harvest whereas wood yield of beech forest was

based on allometric relationship based on diameter at breast

height and tree height. Ryegrass/lucerne ley was mowed three

times during the year and the fodder yield is the sum of three

harvests. The shelterbelt was machine-harvested every 4

years and the actual yield was determined. Average wood

production yr�1 for a full rotation of beech forest (100 years) at

ical quantities of ecosystem services.

cy Production system Method

at CFE wheat, CFE oat, CFE

barley, Cwheat

Harvest of 52 m2 and

weighing

CFE Ryegrass/lucerne ley Harvest of 49.5 m2 and

weighing

y Shelterbelts Harvest and weighing

Beech forest Volume from yield tables

(Møller, 1933)

ight CFE wheat, CFE ryegrass/

lucerne ley, CFE oat, CFE

barley, Cwheat, shelterbelt,

beech forest

5 soil cores of 100 cm3

per treatment

ure CFE wheat, CFE ryegrass/

lucerne ley, CFE oat, CFE

barley, Cwheat, shelterbelt,

beech forest

Correlation between

above & belowground

biomass

CFE wheat, CFE ryegrass/

lucerne ley, CFE oat, CFE

barley, Cwheat, shelterbelt,

beech forest

Bait lamina probes

16 probes per replicate

June CFE wheat, CFE ryegrass/

lucerne ley, CFE oat, CFE

barley, Cwheat, shelterbelt,

beech forest

Elemental analysis

e

CFE wheat, ryegrass/lucerne

ley, oat, barley, Cwheat,

shelterbelt, beech forest

Soil thermometer,

Time domain

reflectometer (TDR)

CFE wheat, ryegrass/lucerne

ley, oat, barley, Cwheat,

shelterbelts, beech forest

Mustard solution

extraction and

hand sorting

e n v i r o n m e n t a l s c i e n c e & p o l i c y 3 9 ( 2 0 1 4 ) 1 3 9 – 1 4 9142

the Frederiksborg site was based on yield tables for beech in

Denmark (Møller, 1933). The prevailing grain prices for CFE

wheat, CFE barley, CFE oat and Cwheat were US$ 0.49, 0.45,

0.49 and 0.25 kg�1 respectively and straw prices were US$ 0.16

and 0.12 kg�1 for CFE food and Cwheat respectively

(www.farmtalonline.dk/, accessed on 20.09.12). The fodder

component of ryegrass/lucerne was priced at US$ 0.16 kg�1

based on the prevailing farm gate price in Denmark

(www.farmtalonline.dk/, accessed on 20.09.12), a database

managed by the Danish Agricultural Advisory service. The

price of the woodchip was calculated as US$ 0.14 kg�1 dry

weight of woodchip biomass, based on the sale price received

for the wood chippings from the nearby heat generation plant

(Halsnæs municipality). The value of produced wood is based

on the different share of beech wood products (Suadicani,

2012) constituting 20%, 20%, 40% and 20% of sawlog, wood-

flooring, firewood and woodchip production and priced at

US$139, 80, 116 and 80 m�3 respectively based on the

prevailing prices in Denmark (DFA, 2012; DNA, 2012).

3.2. Regulating services

3.2.1. Water holding capacityWater holding capacity was measured as the quantity of soil

moisture stored in the plough layer (25 cm deep), available for

plant growth and production. The economic value of soil

moisture is the cost for extraction and subsequent application

in the field, which was worked out as US$ 20 for 100 mm of

water ha�1 based on the information available from the local

agriculture advisory service (www.landbrugsinfo.dk/,

accessed on 04.06.13).

3.2.2. Carbon sequestrationOnly carbon sequestration is considered as a contribution to

mitigation of climate change whereas dynamics of the other

greenhouse gases like nitrous oxide and methane are not

accounted for in this study.

Different methods were used for total biomass accumula-

tion estimates of aboveground and belowground components.

In the croplands, total biomass accumulation was based on

the relationship that grain yield constituted 30% of the total

above and belowground biomass accumulated (Evrendilek and

Wali, 2004). For the ryegrass/lucerne ley, data was available

from another field study in Denmark (Soussana et al., 2010).

For beech forest, total biomass carbon sequestration yr�1 over

a full rotation (100 years) was determined based on above-

ground biomass estimated from yield tables (Møller, 1933) by

use of the biomass expansion factor reported for Danish beech

stands (Skovsgaard and Nord-Larsen, 2012). Carbon stocks

were calculated from the biomass as 45% of the total biomass

(Porter et al., 2009) in cereals/sward whereas 50% of the

biomass was assumed to be carbon in beech forest (Skovs-

gaard and Nord-Larsen, 2012). The value of carbon sequestered

was taken as US$ 10 t�1 carbon based on the carbon market

price in the European Union Emissions Trading Scheme

(Kossoy and Ambrosi, 2010).

3.2.3. Soil erosion preventionSoil erosion is dependent on the extent of vegetation cover and

the type of vegetation. Soil erosion in different production

systems were calculated based on the findings reported by a

European-wide study for different production systems (de la

Rosa et al., 2000). The values for soil erosion prevention were

based on the quantity of soil erosion ha�1 yr�1 multiplied by

the economic value of soil in Denmark, which is equivalent to

US$ 53.6 t�1 based on the price of the soil available for

vegetable gardens (www.lyngenaturgoedning.dk/, accessed

on 04.06.13).

3.2.4. Shelterbelt effectsThe shelter belt effects are the increase in grain and straw

yield due to the microclimate effects, reduced wind erosion

and crop damage and increased availability of moisture (Kort,

1988). Studies in Denmark has demonstrated grain yield

increase in ryegrass/lucerne ley, oat, barley and wheat of 23%,

19%, 18% and 15% (Als, 1989; Soegaard, 1954) respectively and

the grain yield and straw benefits were converted into

economic value based on the prices for agricultural products

in Denmark (www.farmtalonline.dk/, accessed on 20.09.12).

3.2.5. Symbiotic nitrogen fixationNitrogen fixation in ryegrass/lucerne ley is determined based

on the dry matter yield (Hogh-Jensen et al., 2004) and the

nitrogen fixation in alder is assessed based on field measure-

ments in Estonia (Uri et al., 2011). The fixed N was valued based

on the price of US$ 0.48 kg�1 nitrate fertilizer at the

experimental farm in Taastrup in Denmark (www.gf.life.-

ku.dk/, accessed on 04.06.13).

3.2.6. Pollination and biological control of pestsThe pollination value was measured in the CFE experimental

farm and the corresponding economic values are based on the

cost involved in hiring the beehives for pollination to take

place (Porter et al., 2009). In CFE, the pollination service was

equivalent to hiring one bee hive equivalent to US$ 170 hive�1.

Similarly, economic value of biological control of pests were

field-evaluated in the CFE experimental farm in 2009 based on

the natural control of aphids and blowflies (Porter et al., 2009)

in CFE wheat fields due to the presence of predators in the

ryegrass/lucerne ley and shelter belts. The value of biological

control was worked out as US$ 36 ha�1 yr�1 based on the cost

of pest control in winter wheat in conventional crop

production system at the experimental farm in Taastrup in

Denmark (www.gf.life.ku.dk/, accessed on 04.06.13).

3.3. Supporting services

Supporting ES encompasses a number of ecosystem processes

like primary production, production of oxygen etc. but our

study is limited to two important ES as mentioned below.

3.3.1. Nitrogen mineralisationFor determination of nutrient cycling, nitrogen mineralisation

was calculated based on the feeding activity of microbes on

bait lamina probes. Bait lamina probes consisted of PVC strips

(dimension 15–20 cm � 0.5 cm) with 16 holes (dia. 1 mm), filled

with bait material (mixture of cellulose powder, bran flakes,

agar-agar etc.) and exposed to biogenic decomposition process

in the soil at 0–10 cm depth for measurement of the biological

activity of the soil (Vontorne, 1990). The lamina probes were

e n v i r o n m e n t a l s c i e n c e & p o l i c y 3 9 ( 2 0 1 4 ) 1 3 9 – 1 4 9 143

bought from terra projecta GmbH, Germany. The exposure

duration was 10 days in June and soil moisture and soil

temperature were recorded at the time of placement and at

the time of harvest of lamina probes. After harvesting the

lamina probes, the strips are washed under flowing tap water

and examined whether the baits were eaten or not by holding

the strips against a lighted bench. The percent of feeding

activity is based on the number of baits consumed per strip

(Kratz, 1998) and the rate of nitrogen mineralisation was

calculated as (Porter et al., 2009).

Nitrogen mineralisation ðkg ha�1 yr�1Þ ¼ n � b � v � k � 10�3

where n is the total amount of nitrogen (%) in soil, b is the bulk

density of soil (tonne m�3), v is the volume of soil (m3), k is the

percentage mineralisation (%) equivalent to % bait consumed

in probes. The economic value of the mineralised nitrogen is

estimated based on US$ 0.48 kg�1 nitrate fertilizer at the

experimental farm in Taastrup in Denmark (www.gf.life.-

ku.dk/, accessed on 04.06.13).

3.3.2. Soil formationSoil formation was estimated from earthworm activity, i.e.

the amount of topsoil turned over yr�1 based on the

abundance and mass of the earthworms. Earthworms were

extracted by a combination of three methods in beech

forest and shelterbelts and two methods in arable crop and

ryegrass/lucerne ley. In the beech and shelterbelts, firstly,

epigeic earthworm species mainly living in the litter layer

were collected from the litter within a sampling area of

0.25 � 0.25 m2 plots. Secondly, anecic earthworms, living in

vertical burrows, were extracted with 30 L of mustard

solution (Eisenhauer et al., 2008) from the same sampling

area but enclosed with wooden planks and thirdly,

endogeic earthworms were extracted by digging out the

soil to a depth of 25 cm within the sampling area and hand

sorting to catch the remaining earthworms within the soil

volume. Only the second and third method was applied in

arable crop and ryegrass/lucerne ley treatments. In the first

and the third extraction method, the litter or soil was

emptied into a polythene sheet and observed earthworms

were picked up with forceps and immediately killed by

dipping into 95% alcohol solution. In the second method,

mustard solution was prepared by mixing 6 g of mustard

powder per litre water and the mustard solution was

poured into an enclosed 0.25 m � 0.25 m area until the soil

was saturated. The solution percolated through the soil

after which the earthworms came out of the soil due to the

irritation caused by allyl isothiocyanate in mustard. The

same procedure was repeated until 30 L of mustard

solution were poured onto the same sampling unit. The

earthworms extracted by different methods were stored in

different plastic containers and fixed in 95% alcohol for

identification, weighing and to record the number of each

species. The mean biomass of an earthworm was 0.21 g

(this study) and the earthworm biomass is considered

equivalent to the quantity of top soil turned over ha�1 yr�1

(Sandhu et al., 2010b). The value of top soil is estimated at

US$ 53.6 t�1 in Denmark based on the price of the soil

available for sale for vegetable garden (www.lyngenatur-

goedning.dk/, accessed on 04.06.13).

3.4. Cultural

Aesthetic values are based on contingent valuation method,

used by a study in Sweden where values of different

landscapes were determined. The economic values of arable

annual crop, grassland and wooded land were US$ 138, 262

and 332 ha�1 respectively (Drake, 1992, 1999) and same values

are anticipated to be true in Danish landscapes due to the

similarity in cultural and aesthetic values.

4. Economic valuation of total ES

The sum of economic values of provisioning, regulating,

supporting and cultural ES was considered as the total ES

value and calculated as:

EStotal ¼X

ESmarketable þX

ESnon-marktable

where ESmarketable is the sum of the economic values of the

marketable produce and constitutes provisioning ES and

ESnon-marketable is the sum of the economic values of the

regulating, supporting and cultural ES and are non-market-

able. The economic valuation is based on the price in base year

2009 and the prices were deflated to make the ES values

comparable across different ES.

5. Caveats of the ES valuation

5.1 The supporting ES are sometimes argued to be ecosystem

functions or intermediate services facilitating other ES

resulting in double counting (MEA, 2005). We argue that

there are complex causalities within and between ecosys-

tem properties and combinations of different ecosystem

functions and processes contribute to array of ES with no

explicit cause-effect relationship. Hence, ES are valued

best as indirect ES (soil formation, nitrogen mineralisation

etc.) and direct ES (e.g. food and fodder production) to

mankind.

5.2 The total ES accounted for in this study are considered as

relative ES values due to the change in production systems

and management intensities rather than absolute ES

values.

5.3 Ecosystems have both use and non-use values and our

valuation is based only on use values and reflects the

minimum ES values without non-use values like bequest,

existence and the intrinsic value (non-demand value)

which are difficult to value.

5.4 ES values reported are based on a one-time sample in a

time line, and these values can change with sampling

timing and other socio-economic factors in which the

study site is located.

6. Statistical analysis

Means were summarised for variables measured in each

treatment. T-tests were run to assess the significance of

Table 2 – Soil physical and chemical characteristics in 0–10 cm depth in the production systems under study.

Ecosystems Bulk density Soil moisture (%) N% C:N C% Soil temperature (8C)

0–5 cm 5–10 cm

CFE wheat 1.33 17.2 0.15 9.1 1.37 9.1 8.2

CFE ryegrass/lucerne 1.25 17.7 0.19 10.2 1.93 8.2 7.5

CFE Oat 1.19 18.2 0.19 11.2 2.12 8.1 7.6

CFE Barley 1.30 22.0 0.15 14.7 2.21 7.8 7.3

Shelterbelt 1.17 25.8 0.25 15.7 3.93 11.2 10.2

CFEaverage 1.25 20.2 0.19 12.2 2.31 8.9 8.2

Cwheat 1.26 17.4 0.10 13.3 1.33 7.4 7.1

Beech 1.27 26.7 0.12 15.6 1.91 9.0 8.8

LSD(0.05) 0.15 4.5 0.02 1.6 0.24 0.5 0.4

Italics data is used to report soil charactersitics for CFEaverage, Cwheat and beech to emphasize the systems under comparison.

e n v i r o n m e n t a l s c i e n c e & p o l i c y 3 9 ( 2 0 1 4 ) 1 3 9 – 1 4 9144

difference in measured variables like bulk density, soil carbon,

soil nitrogen, biomass accumulation, crop yield, bait lamina

feeding activity, carbon sequestration etc. Differences were

considered significant if P � 0.05. Levels of significance are

denoted as follows: ***significant at P � 0.001, **significant at

P � 0.01, *significant at P � 0.05, ns = not significant. Data were

analysed with the Genstat software package (Genstat 8.1,

2005).

7. Results

7.1. Soil physical and chemical characteristics at the studysites

The soil characteristics of the production systems in terms of

bulk density, soil moisture content (%), N% and C%, C: N ratio

and soil temperature at 0–5 and 5–10 cm soil depth are

provided in Table 2. Comparing CFEaverage and Cwheat and

beech, beech forest had significantly higher soil moisture, C:N

Table 3 – Bio-physical quantification of provisioning, regulatinDenmark.

Ecosystem services Units

Wheat Ryegrass/lucerne

Provisioning

Grain kg ha�1 yr�1 5235 –

Straw kg ha�1 yr�1 3963 –

Fodder kg ha�1 yr�1 – 7908

Wood chips kg ha�1 yr�1 – –

Wood kg ha�1 yr�1 – –

Regulating

Water holding capacity mm 432 382

Carbon sequestration tonne ha�1 yr�1 4 6

Erosion prevention tonne ha�1 yr�1 0 3.6

Shelterbelt effects

Grain increase kg ha�1 yr�1 473 –

Straw increase kg ha�1 yr�1 578 989

Nitrogen fixation kg ha�1 yr�1 – 57

Supporting

Mineralised N kg ha�1 yr�1 121 61

Soil formation

Earthworm count no m�2 118 70

Soil formed tonne ha�1 yr�1 0.2 0.1

ratio and soil temperature at 5–10 cm depth; CFEaverage had

higher N% and C% whereas Cwheat had least C% and N%, soil

moisture and soil temperature at 0–5 and 5–10 cm depth.

Among the CFE treatments, shelterbelts had significantly

higher N%, C% and soil temperature at 0–5 cm and 5–10 cm

depth.

7.2. Bio-physical quantification of ES

The provisioning ES were based on the outputs of food, fodder,

woodchips and merchantable wood products from the

different production systems (Table 3). There was wide

variation in productive capacity of the different production

systems evident from the outputs from each production

system (Table 3). Among the cereal components, Cwheat had

highest grain (7341 kg ha�1 yr�1) yield, followed by CFE wheat,

CFE oat and CFE barley whereas straw yields were highest in

Cwheat (5331 kg ha�1 yr�1) followed by CFE oat, CFE wheat and

CFE barley. Beech wood yields were 27% higher compared to

shelterbelt woodchip yield. In case of the regulating ES, CFE

g and supporting ecosystem services at the trial sites in

CFE CFEaverage Cwheat Beech

Oat Barley Shelter belt

4618 3599 – 3228 7341 –

4802 3147 – 2859 5331 –

– – – 1898 – –

– – 5437 217 – –

– – – 3228 – 6900

432 432 212 411 283 193

7 3 9 5 10 4

– – 3.3 1.0 – 3.3

937 449 – 446 – 473

865 620 – 732 – 1050

– – 152 20 – –

95 141 196 108 64 192

275 63 148 132 136 76

0.6 0.1 0.3 0.3 0.3 0.2

Table 4 – Economic valuation of ecosystem services in the ecosystems under study.

Ecosystem services (US$ ha�1 yr�1) CFE CFEaverage Cwheat Beech

Wheat Ryegrass/lucerne Oat Barley Shelter belt

Provisioning

Food/straw/fodder/bioenergy/wood (1–5) 3208 1271 3040 2112 781 2343 2428 1276

Regulating

Water holding capacity (6) 86 76 86 86 42 82 57 39

Carbon sequestration (7) 42 57 66 33 91 51 98 40

Erosion prevention (8) – 193 – – 177 53 – 177

Shelterbelt effects (9) – – – – 335 335 – 401

Nitrogen fixation (10) – 27 – – 73 9 – –

Pollination (11) – 85 – – 85 24 – –

Pest control (12) – 13 – – 12 4 – –

Subtotal 128 451 152 119 815 558 155 657

Supporting

Nitrogen mineralised (13) 58 29 46 67 94 52 31 92

Soil formation (14) 13 8 29 7 16 14 15 8

Subtotal 71 37 75 74 110 66 46 100

Cultural

Aesthetics (15) 138 262 138 138 332 176 138 332

Total ES 3545 2021 3405 2443 2038 3142 2767 2328

Non-marketable 0.10 0.37 0.11 0.14 0.62 0.25 0.12 0.45

e n v i r o n m e n t a l s c i e n c e & p o l i c y 3 9 ( 2 0 1 4 ) 1 3 9 – 1 4 9 145

wheat, CFE oat and CFE barley contributed to the maximum

water retention of 432 mm in the 0–25 cm plough layer,

followed by CFE ryegrass/lucerne, Cwheat, shelterbelt and

beech. The carbon sequestration was highest in Cwheat

whereas maximum soil erosion prevention was attributed to

ryegrass/lucerne sward followed by shelter belt and beech

forest. The shelter belt effects were assumed to be similar in

shelter belts and beech forest with increase of 473 kg ha�1 yr�1

grain and 1050 kg straw ha�1 yr�1 whereas the nitrogen

fixation in shelterbelts (alder) were higher by 1.7 times

compared to ryegrass/lucerne sward. The supporting ES were

evaluated by determining the mineralised N and soil formed.

The mineralised N was highest in shelter belts

(196 kg ha�1 yr�1) and beech forest (192 kg ha�1 yr�1) and

lowest in Cwheat (64 kg ha�1 yr�1) and ryegrass/lucerne sward

(61 kg ha�1 yr�1). The highest number of earthworms and thus

correspondingly higher quantity of topsoil formed was

recorded in CFE oat (275 no m�2) followed by shelter belts

and Cwheat.

7.3. Economic valuation of total ES

Among the production systems, the total ES value ranged from

US$ 2021– 3545 ha�1 yr�1 with the highest ES value recorded in

CFE wheat and lowest in CFE ryegrass/lucerne sward (Table 4).

Among the CFE treatments, CFE wheat had the highest total ES

values whereas CFE ryegrass/lucerne ley had lowest total ES

values. Comparing the CFEaverage, Cwheat and beech, CFEaver-

age had the highest total ES value, followed by Cwheat and

beech. The provisioning ES consisting of grain, straw, grass,

woodchip and wood yields from the respective production

systems varied widely with corresponding differences in the

economic values of the outputs (Table 4). Comparing CFEaver-

age, Cwheat and beech provisioning ES, Cwheat had the

highest economic values, higher by US$ 85 and US$

1152 ha�1 yr�1 compared to CFEaverage and beech respectively.

Among the provisioning services in CFE treatments, harvest

from the CFE wheat had the highest economic values whereas

CFE ryegrass/lucerne ley had lowest economic values. The

economic values of regulating ES differed widely among the

production systems with lowest value in Cwheat (US$

155 ha�1) and significantly higher values in CFEaverage (US$

558 ha�1 yr�1) and beech (US$ 657 ha�1 yr�1). Among the

regulating ES values, shelterbelt effects in CFE and beech

provided the highest economic values (US$ 335–401 ha�1 yr�1)

due to increase in grain and straw yield whereas it was non-

existent in Cwheat. Second to shelterbelts, soil erosion

prevention had high economic values in ryegrass/lucerne

ley (US$ 193 ha�1 yr�1), beech and shelterbelt (US$

177 ha�1 yr�1) with no such benefits in Cwheat. In Cwheat,

although carbon accumulation was higher, beech and CFE had

the distinctive advantage of higher economic values of

regulating ES due to nitrogen fixation, erosion prevention,

pollination and biological pest control. The economic values of

supporting services in terms of mineralised N and soil

formation were higher in CFE and beech by US$ 20 and US$

54 ha�1 yr�1 respectively compared to Cwheat. The aesthetic

values were highest in beech, followed by CFE and Cwheat.

7.4. Marketable and non-marketable ES in the ecosystems

There was a huge difference in the marketable and non-

marketable share of total ES values. Marketable ES constituted

88% of the total ES in Cwheat whereas the shares in the

CFEaverage and beech were 75% and 55% of total ES respectively

(Fig. 1). Conversely, non-marketable increased in the order

12%, 25% and 45% of total ES in Cwheat, CFEaverage and beech

respectively. Of the non-marketable ES, regulating ES in beech

and CFEaverage was higher by US$ 502 and 403 ha�1yr�1 and

constituted 28% and 18% of total ES (Fig. 1) respectively

compared to only 6% of total ES in Cwheat. Similarly, the non-

marketable values of supporting services in terms of miner-

0

50

100

Provisio ning Regula �ng Supp or� ng Cultu ral

Cwheat

CFE average

Beech

% to

tal e

cosy

stem

serv

ice

(ES)

Ecosystem se rvic e ca teg ories

Fig. 1 – Share of provisioning, regulating, supporting and

cultural ES in Cwheat, CFEaverage and beech.

e n v i r o n m e n t a l s c i e n c e & p o l i c y 3 9 ( 2 0 1 4 ) 1 3 9 – 1 4 9146

alised N and soil formation in CFE and beech were higher by

US$ 20 and US$ 54 ha�1 yr�1 respectively due to higher values

of mineralised nitrogen (US$ 52–92 ha�1 yr�1) compared to

Cwheat. The cultural ES was higher in beech constituting 14%

of total ES compared to CFEaverage (6%) and Cwheat (5%).

8. Discussion

8.1. Bio-physical quantification and economic valuation ofES

With the push for production of more food, fodder, fibre and

energy for the increasing population, our agro-ecosystems are

under tremendous pressure and continuously modified with

chemical inputs to produce more within the available land.

This has adverse effects on the regulating and supporting ES,

which are considered as ‘free inputs’ from the nature and

taken for granted for all times to come (MEA, 2005; UKNEA,

2011). Hence, ES need to be quantified and valued to avoid

continued loss (MEA, 2005). Given the inextricable link

between ES and the human well-being, the continued

degradation of ES may threaten the very existence of life in

terms of food, water and energy production. Hence, ES

valuation is the first step in recognizing its significance in

food, fodder and energy production in our agro-ecosystems.

Our study attempted to put a price tag on 15 indicators of ES in

diverse ecosystems from highly ‘engineered’ arable produc-

tion system (Cwheat) in one extreme to the CFE and beech in

the other extreme. Our total ES value for Cwheat was lower by

US$ 913 ha�1 yr�1 than total ES reported for 12 ES in

conventional arable production system in a study in New

Zealand (Sandhu et al., 2008) due to higher economic values of

provisioning ES, as high as US$ 3258 ha�1 yr�1 compared to our

value of US$ 2428 ha�1 yr�1. Similarly, the study in New

Zealand valued the total ES of organic fields at US$

4600 ha�1 yr�1 compared to our comparatively lower CFEaverage

total ES of US$ 3142 ha�1 yr�1. Since the crop yields and the

prices used for valuation in the New Zealand study were not

provided, it is difficult to ascertain whether the difference is

attributed to the grain and straw yield or price. The economic

valuation of 3 ES viz. biological control, soil formation and

mineralised N in New Zealand in organic and conventional

farms (Sandhu et al., 2010b) were comparable to valuation of

the same ES in CFEaverage (US$ 122 ha�1) and Cwheat (US$

46 ha�1) respectively with higher non-marketable values in

organic similar to our CFEaverage compared to the conventional

production system.

In an earlier study in the CFE, the economic valuation of 9

ES in CFE ryegrass/lucerne, CFE cereal (combined average for

cereals in CFE), shelterbelt and CFEaverage were US$ 1134, 998,

1146 and 1074 ha�1 yr�1 respectively (Porter et al., 2009), two

to three times lower than the total ES values (US$ 2021–

3545 ha�1 yr�1) reported for the same production systems in

our study. There are number of reasons for differences of ES

values between the earlier and the present study made on

the CFE. Firstly, the low values in the earlier CFE study is due

to the low food and fodder ES values between US$ 216–

515 ha�1 yr�1 compared to our range of US$ 1271–

3208 ha�1 yr�1. Secondly, only one combined average yield

is reported to represent cereal component compared to our

study where we separated CFE wheat, CFE barley, CFE oat

and valuation made based on the prevailing price in

Denmark. Thirdly, the grain and straw yields in the earlier

study was only from 2006 whereas our study provided mean

of 2002–2012, which is more representative by compensating

for inter-annual variation. Lastly, the price used for

economic valuation in the earlier study was not provided

compared to our study where prices for different grain and

straw products are provided. Hence, both biophysical

quantification and prices are minimum data requirements

for comparison and synthesis of ES assessments based on

different studies.

In comparison to our ES valuation, the valuation of

pollination, biological control and food production was US$

92 ha�1 yr�1 (Costanza et al., 1997) in croplands and US$

302 ha�1 yr�1 (Costanza et al., 1997) in forest, lower by 7–31

times compared to the same ES in our study. The difference in

ES valuation is attributed to the value transfer from a certain

number of study sites and extrapolation to the coarse global

scale assuming homogeneity of ES from similar ecosystems,

which can differ significantly depending on the socio-

economic settings.

Different methods of valuation can provide contrasting

values for a single ES and hence methodological differences

need to be taken into account. Even though similar methods

were followed in studies above (Sandhu et al., 2010b; Porter

et al., 2009), there was wide differences in values and hence

both biophysical quantification and prices used are re-

quired to refine our ES values. Even though prices may

depend on the context, the basis of biophysical quantifica-

tion for valuation is robust and which can be used for

decision making. Since our indicators for different ES like

earthworm count, nitrogen mineralised etc. are based on

the actual ecological processes and their assessment in the

field, the methods provides objectivity for comparison of ES

values across locations and production systems. However,

the inherent differences between different land uses and

management regimes and non-comparability of the out-

puts are often challenges faced in selection of common

indicators of ES.

e n v i r o n m e n t a l s c i e n c e & p o l i c y 3 9 ( 2 0 1 4 ) 1 3 9 – 1 4 9 147

8.2. Segregating the marketable and non- marketable ES

The demand for increased food and fibre production from

modern-day agriculture has tremendously increased the

provisioning service of food production, i.e., the marketable

share of ES. However, such practices have neglected the

importance of regulating and supporting ES, the core ES, upon

which provisioning ES hinges on, due to their non-marketable

characteristics (UKNEA, 2011; TEEB, 2010) .The continued

practice of conventional agriculture can have negative long-

term effects due to declining ES on sustaining food production

for the projected 9 billion people by 2050 (Pimentel and Wilson,

2004). Our investigation showed that non-marketable ES

decreased in the order beech (US$ 1089 ha�1 yr�1) > CFEaverage

(US$ 800 ha�1 yr�1) > Cwheat (US$ 339 ha�1 yr�1) indicating

that the conventional production system was characterised by

least non-marketable ES due to the single focus on food

production (provisioning ES) only and negligence of other ES. A

similar trend of higher non-marketable ES was recorded in

organic production systems (US$ 1480 ha�1 yr�1) compared to

conventional production system (US$ 670 ha�1 yr�1) in New

Zealand (Sandhu et al., 2008) due to benefits of biological pest

control and higher economic values of nitrogen mineralised and

shelterbelt effects. An earlier study of economic valuation of 9

ES in the CFE system (Porter et al., 2009) found that the non-

marketable ES reached a maximum in CFE ryegrass/lucerne ley

(US$ 918 ha�1) followed by CFE shelter belt (US$

546 ha�1 yr�1 yr�1) and CFE cereal component (US$

483 ha�1 yr�1), which corresponded with our findings with

the maximum in beech and least in cereal component.

The share of non-marketable to total ES value was found to

be higher in an earlier study in CFE (Porter et al., 2009) which

reported 48% in CFE cereal and CFE shelterbelt and 81% in CFE

ryegrass/lucerne sward in comparison to 11%, 62% and 32% in

CFE cereal (mean of cereal components in CFE), CFE shelter

belt and CFE ryegrass/lucerne sward respectively in this study.

The high share of non-marketable ES is attributed to the low

share of the food (US$ 515 ha�1 yr�1) fodder (US$ 216 ha�1 yr�1)

and energy component (US$ 600 ha�1 yr�1) compared to our

values of food (US$ 2787 ha�1 yr�1), fodder (US$ 1271 ha�1 yr�1)

and energy (US$ 781 ha�1 yr�1) production. A comparison of

organic and conventional production system in New Zealand

(Sandhu et al., 2008) reported 32% and 18% of the total share of

ES as non-marketable, which was equivalent to our findings of

25% and 12% in CFEaverage and Cwheat respectively. Another

study (Costanza et al., 1997) at global scale estimated the share

of non-marketable at 41%, 71% and 75% from cropland,

grassland and forest (Costanza et al., 1997) respectively,

comparatively higher than our values of 12%, 37% and 45%

in Cwheat, ryegrass/lucerne sward and beech respectively.

8.3. Significance of valuation for land managers andpolicy-makers

Agro-ecosystems are both producers and consumers of ES.

However, the balance of production and consumption of ES on a

farm or field scale depends largely on the production system

and management intensity as evident from our study. With 60%

of the key ES on the decline (MEA, 2005) at the global scale

augmented by country level assessment(TEEB, 2010; UKNEA,

2011), there is a need for concerted effort by various

stakeholders viz. land managers in the countryside, policy

makers, business enterprises etc. to maintain or enhance the

stock and flow of ES. Given the particular threat to the key non-

marketable ES like regulating, supporting and cultural ES, they

are particularly vulnerable to be further degraded, which have

adverse consequences on the productive capacity of the land in

term of nutrient cycling, water holding capacity etc. affecting

our agriculture production, agriculture-related enterprise and

the socio-economic prosperity. The recognition of value

attached to carbon sequestration, soil erosion prevention etc.

will not only help maintain the agricultural productivity but also

mitigate climate change by storing carbon. The magnitude of

mitigation effects on climate change can be gauged from the

fact that globally land use accounts for 1.5 � 109 tonnes of

carbon (Houghton, 2007) equivalent to 5.5 � 109 tonnes of

equivalent CO2. At EU and national levels, various policy

instruments exists viz. Environmental Action Programme,

Nitrate Directive, Water Framework Directive, Post 2005

Common Agricultural Policy, Good Agricultural and Environ-

mental condition, cross compliance (European Commission,

2011, 2013) to facilitate an ES-based approach to land manage-

ment. Our ES valuation exercise in diverse production systems

demonstrated that ‘softer’ agriculture practices like organic

practice in CFE were conducive to higher ES provision and such

context-specific ES assessments are useful inputs for formulat-

ing local environment action plans (O’Neill and Spash, 2000) at

the farm/national scale and for ‘benefit transfer’ approach for

cost-benefit analysis of agri-environmental schemes (Navrud

and Bergland, 2001) at the regional or EU scale. At the local level,

the ES values from this study can be used to calculate ES value of

farms based on the different production systems practised on-

farm, as a basis for payment for ecosystem services. In a

national/regional and European context, these ES values can be

used to assess the value of marketable and non-marketable ES

based on the share of the productions systems at a given scale.

With ecosystem based management gaining priority today,

such ES valuation exercise can be useful input in formulation of

agri-environmental policies at different scales. The additional

benefits of CFE in terms of bio-energy production is comple-

mentary to the existing EU targets on production of renewable

energy on-farm and ES values can be used as an argument to

assess competing benefits of land use. With insight into ES in

production systems, policy design can be targeted to optimise

food, fodder and energy production with a long-term goal of

sustained ES provision to maintain the productive capacity of

land. Although monetary valuation may not reflect the plurality

of ES values, the policy makers need economic valuation as a

tool to respond to appreciation of the value of nature for

providing ES. Taking on-board the non-marketable ES would

not only help consider the full range of costs and benefits of a

use of ES but can also aid in efficient allocation of natural

resources as part of environmental protection scheme at

country as well as regional scale.

Acknowledgements

We appreciate the financial support from EC SmartSOIL

project (Project number: 289694) for funding the laboratory

e n v i r o n m e n t a l s c i e n c e & p o l i c y 3 9 ( 2 0 1 4 ) 1 3 9 – 1 4 9148

analysis expenses and ‘Fuel for life’ project for funding the

biomass harvest and soil sampling activities during the

experimental period.

r e f e r e n c e s

Als, C., 1989. How to succeed in planting 900 km of shelterbeltsper year in a small country like Denmark. Soil Technol. Ser.1, 25–27.

Amiaud, B., Carrere, P., 2012. Grassland multifunctionality inproviding ecosystem services. Fourrages 229–238.

Banzhaf, H.S., 2010. Economics at the fringe: non-marketvaluation studies and their role in land use plans in theUnited States. J. Environ. Manage. 91, 592–602.

Costanza, R., dArge, R., deGroot, R., Farber, S., Grasso, M.,Hannon, B., Limburg, K., Naeem, S., Oneill, R.V., Paruelo, J.,Raskin, R.G., Sutton, P., vandenBelt, M., 1997. The value ofthe world’s ecosystem services and natural capital. Nature387, 253–260.

Daily, G.C., Polasky, S., Goldstein, J., Kareiva, P.M., Mooney, H.A.,Pejchar, L., Ricketts, T.H., Salzman, J., Shallenberger, R., 2009.Ecosystem services in decision making: time to deliver.Front. Ecol. Environ. 7, 21–28.

de la Rosa, D., Moreno, J., Mayol, F., Bonson, T., 2000.Assessment of soil erosion vulnerability in western Europeand potential impact on crop productivity due to loss of soildepth using the ImpelERO model. Agric. Ecosyst. Environ. 81,179–190.

DFA, 2012. The Wood Price Statistics of Danish ForestAssociation. .

DNA, 2012. Danish Nature Agency (https://www2.naturstyrelsen.dk/netbutik/braende/, accessed on20.09.12).

Drake, L., 1999. The Swedish agricultural landscape – economiccharacteristics, valuations and policy options. Int. J. Soc.Econ. 26, 1042–1062.

Drake, L., 1992. The non-market value of the Swedishagricultural landscape. Eur. Rev. Agric. Econ. 19,351–364.

Eisenhauer, N., Straube, D., Scheu, S., 2008. Efficiency of twowidespread non-destructive extraction methods under drysoil conditions for different ecological earthworm groups.Eur. J. Soil Biol. 44, 141–145.

Engle, V.D., 2011. Estimating the provision of ecosystem servicesby gulf of mexico coastal wetlands. Wetlands 31,179–193.

Evrendilek, F., Wali, M., 2004. Changing global climate: historicalcarbon and nitrogen budgets and projected responses ofOhio’s cropland ecosystems. Ecosystems 7, 381–392.

European Commission, 2011. Communication from theCommission to the European Parliament, the Council, theEconomic and Social Committee and the Committee of theRegions, Our Life Insurance, Our Natural Capital: an EUBiodiversity Strategy to 2020. 244.

European Commission, 2013. A Resource-efficient Europe –Flagship Initiative under the Europe 2020 Strategy. .

Farley, J., Costanza, R., 2010. Payments for ecosystem services:from local to global. Ecol. Econ. 69, 2060–2068.

Hao, F., Lai, X., Ouyang, W., Xu, Y., Wei, X., Song, K., 2012. Effectsof land use changes on the ecosystem service values of areclamation farm in Northeast China. Environ. Manage. 50,888–899.

Hogh-Jensen, H., Loges, R., Jorgensen, F., Vinther, F., Jensen, E.,2004. An empirical model for quantification of symbioticnitrogen fixation in grass-clover mixtures. Agric. Syst. 82,181–194.

Houghton, R.A., 2007. Balancing the global carbon budget. Annu.Rev. Earth Planet Sci. 35, 313–347.

Kort, J., 1988. Benefits of windbreaks to field and forage crops.Agric. Ecosyst. Environ. 22–3, 165–190.

Kossoy, A., Ambrosi, P., 2010. State and Trends of the CarbonMarket. World Bank, Washington, DC.

Kratz, W., 1998. The bait-lamina test – general aspects,applications and perspectives. Environ. Sci. Pollut. Res. 5,94–96.

Liu, G., Li, Y., Alva, A.K., Porterfield, D.M., Dunlop, J., 2012a.Enhancing nitrogen use efficiency of potato and cereal cropsby optimizing temperature, moisture, balanced nutrientsand oxygen bioavailability. J. Plant Nutr. 35, 428–441.

Liu, Y., Li, J., Zhang, H., 2012b. An ecosystem service valuation ofland use change in Taiyuan City, China. Ecol. Model 225,127–132.

MEA, Millenium ecosystem assessment, 2005. Ecosystems andHuman Well-being: Biodiversity Synthesis. .

Mendoza-Gonzalez, G., Martinez, M.L., Lithgow, D., Perez-Maqueo, O., Simonin, P., 2012. Land use change and itseffects on the value of ecosystem services along the coast ofthe Gulf of Mexico. Ecol. Econ. 82, 23–32.

Møller, C.M., 1933. Bonitetsvise tilvækstoversigter for bøg, eg ogrødgran i Danmark. Dansk Skovbrugs Tidsskrift 18 .

Navrud, S., Bergland, O., 2001. Value Transfer andEnvironmental Policy. Cambridge Research for theEnvironment.

Niu, X., Wang, B., Liu, S., Liu, C., Wei, W., Kauppi, P.E., 2012.Economical assessment of forest ecosystem services inChina: characteristics and implications. Ecol. Complex. 11,1–11.

O’Neill, J., Spash, C., 2000. Conceptions of value inenvironmental decision-making. Environ. Values 9,521–535.

Pacini, C., Wossink, A., Giesen, G., Vazzana, C., Huirne, R., 2003.Evaluation of sustainability of organic, integrated andconventional farming systems: a farm and field-scaleanalysis. Agric. Ecosyst. Environ. 95, 273–288.

Pimentel, D., Wilson, A., 2004. World population, agricultureand malnutrition. World Watch 17, 22–25.

Porter, J., Costanza, R., Sandhu, H., Sigsgaard, L., Wratten, S.,2009. The value of producing food, energy, and ecosystemservices within an agro-ecosystem. AMBIO 38, 186–193.

Sandhu, H.S., Wratten, S.D., Cullen, R., 2010a. Organicagriculture and ecosystem services. Environ. Sci. Policy 13,1–7.

Sandhu, H.S., Wratten, S.D., Cullen, R., 2010b. The role ofsupporting ecosystem services in conventional and organicarable farmland. Ecol. Complex. 7, 302–310.

Sandhu, H.S., Wratten, S.D., Cullen, R., Case, B., 2008. The futureof farming: the value of ecosystem services in conventionaland organic arable land, An experimental approach. Ecol.Econ. 64, 835–848.

Skovsgaard, J.P., Nord-Larsen, T., 2012. Biomass, basic densityand biomass expansion factor functions for European beech(Fagus sylvatica L.) in Denmark. Eur. J. For. Res. 131 (4)1035–1053.

Soegaard, B., 1954. Outline of shelterbelts and shelterbelt testsin Denmark. In: IUFRO 11th Cong. Proc. 1953 (Rome) Sec, 11.pp. 246–269.

Soussana, J.F., Tallec, T., Blanfort, V., 2010. Mitigating thegreenhouse gas balance of ruminant production systemsthrough carbon sequestration in grasslands. Animal 4,334–350.

Suadicani, K., 2012. Sortimentsfordelinger: Til brug fordriftsplanlægningen i Naturstyrelsen. working report. For.Landsc. 1–24.

Tangermann, S., Adinolfi, F., 2011. Direct Payments in the CAPpost 2013. Int. Agric. Policy 1, 21–32.

e n v i r o n m e n t a l s c i e n c e & p o l i c y 3 9 ( 2 0 1 4 ) 1 3 9 – 1 4 9 149

TEEB The Economics of Ecosystems and Biodiversity, 2010.Mainstreaming the Economics of Nature: a Synthesis of theApproach, Conclusions and Recommendations of TEEB. .

UKNEA, 2011. United Kingdom National Ecosystem Assessment(http://uknea.unep-wcmc.org/, accessed on 20.09.12).

Uri, V., Lohmus, K., Mander, U., Ostonen, I., Aosaar, J.,Maddison, M., Helmisaari, H., Augustin, J., 2011. Long-termeffects on the nitrogen budget of a short-rotation grey alder(Alnus incana (L.) Moench) forest on abandoned agriculturalland. Ecol. Eng. 37, 920–930.

von Haaren, C., Kempa, D., Vogel, K., Rueter, S., 2012. Assessingbiodiversity on the farm scale as basis for ecosystem servicepayments. J. Environ. Manage. 113, 40–50.

Vontorne, E., 1990. Assessing feeding activities of soil-livinganimals .1 Bait-Lamina-tests. Pedobiologia 34, 89–101.

w e b r e f e r e n c e s

www.landbrugsinfo.dk/Planteavl/Vanding/Sider/Vurdering_af_oekonomi_i_markvanding.aspx.

www.farmtalonline.dk.www.lyngenaturgoedning.dk.www.gf.life.ku.dk.