Navigation mit Access Keys

Main menu

 
 
 

Between 2020 and 2022 a network of experimental plantations of tree species adapted to future climate is established throughout Switzerland as a joined effort of the Federal Institute for Forest, Snow and Landscape Research (WSL), the Federal Office for the Environment (FOEN), cantonal forest services, forest managers, professional organizations and forest owners. The experimental plantations ,consisting of 55.000 plants, will be monitored for several decades and will allow insights in the suitability of tree species across broad environmental gradients in a changing climate. This network offers a unique infrastructure for practitioners as well as researchers.

 

Current status:

The first planting period started in Autumn 2020 in Bergün (Grisons). Until the end of 2021 31 of 59 sites have been established. All experimental plantations are expected to be installed in spring 2023.

Background:

A warmer climate with drier summers will affect the climatic suitability of tree species in their current habitat and, subsequently, future ecosystem services. On many forest sites other tree species than those in place will grow better towards the end of the 21st century. While some tree species already grow on sites where the future climate is supposed to suit them, others are currently still absent.

In this context foresters are exposed to the following question:

Which of the tree species supposedly adapted to the climate expected on a given site towards the end of the 21st century can already establish and grow there today?

 

To find answers to this question the project ‘experimental plantations of tree species adapted to future climates’ was started. Within its scope a network of 50-60 experimental plantations will be established throughout Switzerland and monitored over 30-50 years to find answers to pressing issues in climate change adaptation. The project will allow verification of results of the research program ‘Forests and climate change’. Its results will help the validation of site-specific tree species recommendations for forest practitioners, and it will create a long-term infrastructure for applied research. The scientific question behind the project is: which factors determine mortality, health and growth of tree species and provenances along large environmental gradients?

The great advantage of this project is the coordinated approach. While a single plantation provides only answers for the specific site, the network allows comprehensive and robust statements on the performance of tree species along large environmental gradients. Thus, this long-term trial will improve our understanding of effects of climate and climatic extremes on the trees species and provenances under investigation. The project is a follow-up activity of the research program "Forest and Climate Change", which FOEN and WSL conducted from 2009 to 2018.

 

Design

All test plantations are consistent in their design which allows reliable statistical analyses. The experimental design includes both the distribution of tree species over the experimental plantations and the arrangement of plants within each site. The design has been worked out in collaboration with researchers and revised by external statisticians. The 59 experimental plantations are distributed over all biogeographic regions and altitudinal belts occurring in Switzerland. Every experimental plantation is split in three blocks. The blocks are split in as many plots as there are tree species assigned to a specific site. All tree species will be planted once in every block and assigned randomly to a plot within the block. The number of tree species tested per site and therefore the number of plots and the size of the plantation is variable. Each plot is split in four subplots to which four provenances per tree species are assigned randomly. Finally, every subplot contains nine individual trees.

The area needed for a test plantation is given by the number of tree species assigned to this site and by the height of the neighboring stands, which determines the width of the buffer zone needed. The spacing between plants is 2 m, between plots 4 m. The area needed for a test plantation with 4 tree species is approximately 0.75 ha. A plantation with 10 tree species requires  approximately 1.3 ha.

To record the local climate, an automated climate station is operated on each experimental site. It measures among other things soil moisture .

Detailed information about the experimental design can be found in the report ‘Versuchsdesign für Testpflanzungen’ (available in German and French only).

 

Plantation sites

In mid-March 2018 the cantons have been invited to propose experimental sites meeting  the requirements described in the report ‘Site selection for experimental plantations’ (only available in German and French). From November 2018 to July 2019, the WSL project team visited 125 of the 172 sites proposed by the cantonal forest services. In July 2019, 57 sites were selected and the tree species to be tested on each site were assigned (report `Site selection for experimental plantations’ (only available in German and French). Later, minor changes were made to the selection of sites and tree species allocation, and two sites were added in the canton of Baselland.

All experimental plantation sites are contractually secured for the long term.

The 59 experimental plantations are distributed over all biogeographic regions and altitudinal belts  occurring in Switzerland. Depending on site size, four to 18 tree species are tested in an experimental plantation. On six sites (‘supersites’), all 18 tree species are tested.

Table of all experimental plantations sorted by number.

Number TS = Number of tree species tested on site

Planting period = Planting period in which the site is established

1 means fall 20 to spring 21, 2 means fall 21 to spring 22, 3 means fall 22 to spring 23.

No.

Canton

Municipality

Locality

Number TS

PP

Month

Year

1

AI

Schwende

Berneregg

6

1

May

21

4

GR

Safiental

Gampel

5

2

Sept

21

9

ZH

Oberrieden

Neuforst

6

1

Mar

21

10

LU

Emmen

Oberschiltwald

6

3

Nov

22

11

LU

Pfaffnau 

Birchwald

6

3

Mar

23

15

LU

Escholzmatt-Marbach

Buhhütte

10

1

May

21

16

GR

Val Müstair

Cuoir

10

2

May

22

17

GR

Bregaglia

Dre Mota

7

1

Oct

20

18

GR

Valsot

Vadrain

6

3

Oct

22

22

GR

Samedan

Sur Plaun God

8

2

May

22

25

FR

Bulle

La Joretta

8

1

Oct

20

26

FR

Belmont-Broye

Forêt du Grand Belmont

8

1

Nov

20

28

SZ

Schwyz

Galleren

8

2

May

22

36

SZ

Feusisberg

Friesisschwand

8

2

Apr

22

37

GR

Albula/Alvra

Tgavrouls

6

3

 

 

38

GR

Bergün Filisur

Spena

8

1

Sep

20

42

AG

Villigen

Güllenholz

8

3

Nov

22

43

AG

Murgenthal

Fätzholz

6

3

Mar

23

45

SO

Seewen

Holzenberg

6

3

Nov

22

47

SO

Luterbach

Dorn-Ischlag

8

1

Nov

20

48

SO

Himmelried

Steffenschmiede

8

2

Nov

21

50

GE

Presinge

Le Bois des Eaux

8

1

Nov

20

51

SH

Schaffhausen

Rändli

18

3

Oct

22

54

ZH

Aesch (ZH)

Seegaden

4

2

Nov

21

66

BL

Arisdorf

Eileten

18

2

Nov

21

68

SG

Gaiserwald

Hoferst

8

2

Mar

22

72

SG

Quarten

Oberer Nüchen

6

1

May

21

74

SG

Amden

Vorem Platt

6

3

Sep

22

80

SG

Uznach

Chrüzweg

8

1

Nov

20

82

VD

Froideville

Jorat d'Echallens

10

1

Nov

20

85

VD

Apples

Bois de Saint Pierre

18

2

Mar

22

87

VD

Vallorbe

Crêt Cantin

8

3

Mar

23

91

VD

Château-d'Oex

Les Jeurs

10

2

Sept

21

93

VS

Riederalp

Riederwald

6

2

Sept

21

96

VS

Riddes

Forêt des Conches

8

1

Dec

21

97

VS

Champéry

La Forêt Derrière

8

3

Oct

22

99

VS

Leuk

Baronsächer

6

3

Oct

22

100

VS

Bagnes

Forêt du Marais

6

2

Sept

21

101

TG

Ermatingen

Hauptmeshööli

10

2

Mar

22

105

TI

Serravalle

Caslóu

7

2

Mar

22

108

TI

Losone

Piano di Arbigo

6

2

Nov

21

109

TI

Ronco sopra Ascona

Casone

12

3

Oct

22

118

TI

Stabio

Baragge

4

2

Nov

21

119

TI

Novaggio

Ur Pián Pülpit

10

1

Mar

21

124

UR

Unterschächen

Alt Rüti

8

3

May

23

129

BE

Neuenegg

Ruessemattbode

18

1

Oct

20

131

BE

Rüschegg

Hirschböde

6

1

May

21

132

BE

Innertkirchen

Militalwald

5

3

Apr

23

154

BE

Petit-Val

Droit des Ecorcheresses

6

3

Apr

23

156

BE

Grandval

La Haute Joux

18

2

Apr

22

162

BE

Boltigen

Bäderegg

5

2

May

22

166

BL

Muttenz

Oberi Hard

6

1

Nov

20

167

JU

Haute-Ajoie

Foirgeret

8

2

Nov

21

168

GR

Maienfeld

Fuchsenwinkel

18

2

Oct

21

170

ZG

Unterägeri

Hinterwidenwald

8

2

Oct

21

172

ZH

Zürich

Waldlabor

8

1

Mar

21

173

TI

Locarno

Cappelletta

10

3

Mar

23

174

BL

Buus

Schöönenberg

12

1

Jan

21

175

BL

Pfeffingen

Bielgrabe

8

2

Mar

22

 

Tree species

The tree species to be tested in the fixed design were chosen taking into account the considerations of cantonal stakeholders and experts in a multistage procedure. While nine tree species belong to the core set and will be planted in approximately 35 sites, another nine tree species belong to the extension set and will be planted in only approximately 15 sites. The process of tree species selection is reported in ‘Tree species selection for experimental plantations’ (only available in German and French).

The 18 tree species under investigation comprise many of the species which are probably suitable in future climates. For tree species of the core set reliable results will be generated to analyze and compare their performance over a broad environmental gradient, while for tree species of the extension set the explanatory power will be smaller.

Core set (9 tree species)Ergänzungsset (9 Arten)
Abies alba (silver fir)
Acer pseudoplatanus (Sycamore maple)
Fagus sylvatica (European beech)
Larix decidua (European larch)
Picea abies (Norway spruce)
Pinus sylvestris (Scots Pine)
Pseudotsuga menziesii (Douglas fir)
Quercus petraea (Sessile oak)
Tilia cordata (Small-leaved Lime)
Acer opalus (Italian maple)
Acer platanoides (Norway maple)
Cedrus atlantica (Atlas ceda)
Corylus colurna (Turkish hazel)
Juglans regia (Persian walnut)
Prunus avium (Wild cherry)
Quercus cerris (Turkey oak)
Quercus robur (Pedunculate oak)
Sorbus torminalis (Wild service tree)

 

 

Provenances

For each tree species seven provenances will be tested. In order to keep the size of the experimental plantations manageable only four out of the seven provenances are assigned to each test plantation. While six provenances will be tested in half of the experimental plantations only, one provenance will be tested as reference in all experimental plantations a species is assigned to.  This allows for better coverage of the genetic variability within the tree species, while it keeps site sizes manageable.

The provenances were selected in an elaborate process (report ‘Provenance selection and seedling provisioning’). The plant material was procured in cooperation with several Swiss nurseries and foreign partners. Most of the plants are grown at the Emme AG nursery, a few tree species are also grown at the nursery of the Canton of Ticino (Morbio Superiore) and at the WSL experimental nursery.

 

Funding

The establishment and maintenance of the experimental plantations is partly financed by subsidies from the Federal Office for the Environment. In addition, the cantons contribute significantly to the financing of their own experimental plantation sites.

 

Outlook

The plan is to establish all plantations by spring 2023. Replanting will take place as needed over a two-year period in case of major failures. The forest managers are responsible for planting their sites, the WSL team accompanies the plantings and distributes the plants to the marked planting spots. Maintenance is also the responsibility of the forest managers, which adhere to the specifications of the ‘Guidelines for vegetation management’. In summer of 2021, the condition of the planted trees (on the sites already planted) was recorded for the first time. These inventories are to be carried out annually during the first few years, and later at intervals of several years.

 

Pictures

 

FURTHER INFORMATION