1
Supporting Information
2
Text S1. The changes in feedstuffs for ruminants
3
To our knowledge, data on the past evolution of ruminant diet composition for
4
European countries do not exist. As an alternative, we looked into the evolution of
5
non-grass feedstuffs in Europe. The feedstuff used to feed ruminant livestock was
6
calculated using a simple feed model (Ciais et al., 2007), and the residual feed
7
demand by ruminant livestock was assumed to rely on local forage and grass. The
8
details in the simple feed model and the methodology were described by Ciais et al.
9
(2007). The input data for this feed model are crop trade and harvest statistics from
10
FAOstat - Commodity Balances (hereinafter referred to as FAO-CB, available at
11
http://faostat3.fao.org/) as well as the number of poultry, pigs, sheep and goats, and
12
cattle. From the feedstuff products inventoried in the FAO-CB, we selected 21 major
13
ones including cakes of cereals and oilseeds, brans, pulses and grains compose the
14
diet of farmed pigs and poultry and the concentrates in the diet of farmed ruminants
15
[Kuratorium fur Technic und Bauwessen in der Landwitschaft, 2000]. The supply of
16
these feedstuffs was distributed successively to poultry and pigs according to their
17
specific nutritional demands using this simple feed model, with some country-
18
dependent adjustments for farming intensity. Farming intensity (for poultry feeding)
19
was set to be the same given the fact that the 30 countries considered in this study
20
(EU28, plus Norway and Switzerland) are all developed countries. In Europe, non-
21
cereal crop products and by-products used as feedstuff have continually increased
22
over the last five decades. Grain-feed (mainly wheat and maize) for farm animals
23
increased significantly during 1961-1985, then decreased for 1985-1992, then
24
increasing again after 1992 (Fig. S4a), whereas the total livestock population did not
25
show the same pattern as feedstuffs (Fig. S4b). Poultry kept continually increasing.
26
Pigs and sheep/goats started to decrease since around 1988, and cattle started to
27
decrease even earlier (since 1975). After being distributed to farm poultry and pigs
28
using the simple feed model, the evolution of residual grain-feed for farm cattle
29
(sheep and goats are excluded because the grain-feed consumption by sheep and goats
30
is only 2% of their total dry matter intake; Bouwman et al., 2005) shows a similar
31
variation as grain-feed for all farm animals (Fig. S4a). As a result, the grain-feed
32
consumption per head of cattle doubled during 1961-1984, then declined by 35%
33
between 1985 and 1992, and has again increased rapidly since 1993 (Fig. S4c).
34
However, the fraction of grass-feed in the ruminant diet cannot be simply calculated
35
by subtracting the fraction of feedstuffs in ruminant diet, because the feedstuffs
36
considered in this study are not complete. For example, the medium eared whole-
37
maize silage (green fodder) and the fibrous by-products (e.g., wheat straw, barley
38
straw and maize stover) are not considered. Yet these can comprise a significant part
39
of the total dry matter intake (e.g., residues and fodder comprise 38% of total dry
40
matter intake for beef cattle, 45% for dairy cows and 8% for sheep and goats in
41
western Europe; Bouwman et al., 2005).
42
43
Reference:
44
Beer C, Weber U, Tomelleri E, Carvalhais N, Mahecha M, Reichstein M (2014)
45
Harmonized European Long-Term Climate Data for Assessing the Effect of
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Changing Temporal Variability on Land-Atmosphere CO2 Fluxes. Journal of
47
Climate, 27, 4815-4834.
48
49
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Bouwman AF, Van der Hoek KW, Eickhout B, Soenario I (2005) Exploring changes
in world ruminant production systems. Agricultural Systems, 84, 121-153.
Chang JF, Ciais P, Viovy N, Vuichard N, Sultan B, Soussana J-F
(2015) The
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greenhouse gas balance of European grasslands. Global Change Biology,
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doi:10.1111/gcb.12998.
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Ciais P, Bousquet P, Freibauer A, Naegler T (2007) Horizontal displacement of
54
carbon associated with agriculture and its impacts on atmospheric CO2. Global
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Biogeochemical Cycles, 21, GB2014, doi:10.1029/2006GB002741.
56
FAO-CB (2013) http://faostat3.fao.org/download/FB/BC/E
57
IPCC (2006) 2006 IPCC Guidelines for National Greenhouse Gas Inventories,
58
Prepared by the National Greenhouse Gas Inventories Programme (eds
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Eggleston HS, Buendia L., Miwa K, Ngara T, Tanabe K). IGES, Japan.
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KTBL (Kuratorium fur Technic und Bauwessen in der Landwitschaft) (2000) KTBL
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Pocket Book Agriculture 2000/01 (in German), 20th ed., Kuratorium fur
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Technic und Bauwessen in der Landwitschaft, Munster, Germany.
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Leip A, Britz W, Weiss F, de Vries W (2011) Farm, land, and soil nitrogen budgets
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for agriculture in Europe calculated with CAPRI. Environmental Pollution,
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159, 3243-3253.
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Leip A, Marchi G, Koeble R, Kempen M, Britz W, Li C (2008) Linking an economic
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model for European agriculture with a mechanistic model to estimate nitrogen
68
and carbon losses from arable soils in Europe. Biogeosciences, 5, 73-94.
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Leip A, Weiss F, Lesschen JP, Westhoek H (2014) The nitrogen footprint of food
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products in the European Union. Journal of Agricultural Science, 152, S20-
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S33.
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Olesen JE, Bindi M (2002) Consequences of climate change for European agricultural
73
productivity, land use and policy. European Journal of Agronomy, 16, 239-
74
262.
75
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Table S1 Major agricultural regions in Europe (Olesen & Bindi, 2002).
Grassland area
Regions
Countries
Million ha % of land
Nordic
28.6
27%
Norway, Sweden, and Finland
British Isles
13.5
52%
Ireland, and United Kindom
Denmark, Germany,
Western
29.6
30%
Netherlands, Belgium,
Luxembourg, and France
Portugal, Spain, Italy, Greece,
Mediterranean
26.5
29%
Malta, and Cyprus
Alpine
4.1
34%
Switzerland, and Austria
Poland, Czech Republic, and
North eastern
9.0
21%
Slovakia
Hungary, Slovenia, Croatia,
South eastern
11.1
22%
Romania, and Bulgaria
Eastern
Total
77
4.4
26%
126.7
29%
Estonia, Latvia, and Lithuania
78
79
Figure S1. The evolution of meat productivity of beef cattle and milk productivity of
80
cows in Europe. Data are averaged for EU28 plus Norway and Switzerland. Solid
81
lines indicate the productivities derived from FAOstat; dashed lines are the constant
82
productivities of ruminant livestock in the new calculation of ME requirement
83
assuming that the growth in feed conversion efficiency is consistent with the increase
84
of meat and milk productivities of ruminant livestock after 1991.
85
86
87
Figure S2. Grass-fed livestock numbers in each of major agricultural regions and their
88
evolution during the period 1961-2010. The numbers were converted to livestock unit
89
(LU) based on the calculation of metabolizable energy (ME) requirement of each type
90
of animal with variable (i.e., the growth in feed conversion efficiency is consistent to
91
the increase of meat and milk productivities of ruminant livestock after 1991; dashed
92
lines) or constant (solid lines) feed conversion efficiency.
93
94
95
Figure S3. Spatial distribution of the changing rate (linear trends) during the period
96
1991-2010 in: (a) mean annual temperature, (b) total annual precipitation, (c)
97
nitrogen fertilization, (d) atmospheric nitrogen deposition, (e) grassland area, (f)
98
ruminant livestock numbers and (g) in fraction of intensively managed grassland in
99
total grassland area with constant feed conversion efficiency (FCE) or (h) with
100
assumed changes in FCE. The changing rate in (c) nitrogen fertilization and (d),
101
atmospheric nitrogen deposition are estimated for the period 1991-2000, because in
102
the database they are assumed to be constant from 2000 till 2010. Temperature and
103
precipitation were from ERA-WATCH reanalysis climate forcing data at a spatial
104
resolution of 25 km (Beer et al., 2014). Gridded mineral fertilizer and manure
105
nitrogen application rate was estimated by the CAPRI model (Leip et al., 2011, 2014),
106
based on combined information from official and harmonized data sources such as
107
Eurostat, FAOstat and OECD, and spatially dis-aggregated using the methodology
108
described by Leip et al. (2008); grassland area was extracted from the HILDA data set
109
(Fuchs et al., 2013); ruminant livestock numbers were taken from FAOstat with
110
annual country-averaged statistical data on major ruminant livestock numbers for
111
dairy cows, beef cattle, sheep and goats; livestock species are converted to livestock
112
unit (LU) based on the calculation of metabolizable energy requirement (see
113
Supplementary Information Text S1 of Chang et al., 2015); fraction of intensively
114
managed grassland in total grassland area is as established by Chang et al. (2015),
115
constrained by the total forage requirement (derived from metabolizable energy
116
requirement) of grass-fed livestock numbers.
117
118
119
Figure S4. Temporal evolution of (a) total feedstuff products, (b) farm animal
120
numbers, and (c) feedstuff for ruminant and grain-feed consumption per head of
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ruminant during the last five decades. For the feedstuffs, cereal grains include maize
122
and other cereals; other crop products and by-products included cakes of cereals and
123
oilseeds, brans, and pulses; grain for cattle was the residual grain-feed for cattle after
124
being distributed successively to poultry and pigs using the simple feed model (Ciais
125
et al., 2007). To keep data consistency, the figure shows the total quantities from 23
126
countries of Europe, where data from Croatia, Czech Republic, Estonia, Latvia,
127
Lithuania, Slovakia, and Slovenia were not included in due to the short period of data
128
availability.
129
130
131
Figure S5. Shift in seasonal evolution of grassland GPP during the last two decades in
132
the Nordic countries and the British Isles. The monthly mean GPP of grassland was
133
simulated by ORCHIDEE-GM, aggregated and averaged over each region according
134
to the area and the management intensity (extensively or intensively managed) of
135
grassland in the enhanced historic land-cover maps delineating grassland management
136
intensity (Version 1; see main text section ‘Simulation set-up’ for detail). Decadal
137
averages of monthly GPP (for the period 1991-2000 and 2001-2010 respectively)
138
were used. GPP: gross primary production.
139
140
141
Figure S6. (a) mean nitrogen addition rate over European grassland (including
142
fertilization and atmospheric deposition) and (b) its normalized changing rate during
143
the period 1991-2000. The normalized changing rate of nitrogen addition is calculated
144
as the ratio of changing rate (linear trend) to mean nitrogen addition rate.
145