The role of uneven-aged silviculture in diversifying forests in Britain:to adapt to climate change and increase resilience to pests and diseases

Gary Kerr

Forest Research, Alice Holt Lodge, Farnham, Surrey, United Kingdom.

Structure of presentation

1. Introduction to forests in Britain

2. Future challenges

3. Increasing resilience

4. Conclusions/Future concepts

Distribution of forests in GB

Typical upland plantations of Picea sitchensis

18/04/234

Pests and diseases

Chalara on Ash!!!

1961-90

Forest of Dean Today

Coleford

Forest of Dean 2080

2080s High

The big challenge!

How can we adapt forests to increase resilience to

biotic threats and climate change, whilst maintaining

productivity?

What is resilience?

Resilience: the capacity of a plant community to

maintain or regain normal function and development

following disturbance.

Helms, J. 1998 The dictionary of forestry. CABI International, Oxford.

Ways to increase resilience

Three main options:

1. Species choice and deployment

2. Silvicultural systems / forest structure (thinning)

3. Genetics

Our forests todayConifer Species Today

Scots Pine

Corsican Pine

Sitka Spruce

Douglas Fir

Larch (EL, HL, J L)

Other Conifer

Oak26%

Beech 10%

Sycamore8%

Ash16%

Birch12%

Poplar2%

Sweet chestnut2%

Elm0%

Other Broadleaves11%

Mixed Broadleaves13%

Data Source National Inventory of Woodland -England. Reference date 1998.

• 5 conifer species account for 88% of the total

• 5 broadleaved species account for over 72% of the total

• 10 tree species account for 80% of our woodland!!!!

Broadleaved species today

2. Silvicultural systems

18/04/2313

Sitka spruce at Clocaenog

3. Genetics

Provenance of Abies alba L.

Data were analyzed using GLMM and results showed that site (P=0.026) and provenance (p<0.001) were significant but site x provenance was not significant (p=0.578)

Heights of Abies alba provenances at age 45

14.0

16.0

18.0

20.0

22.0

24.0

26.0

28.0

30.0

60

(497

1)1

03

60

(453

2)1

00

60

(448

7)

60

(438

3)1

00

59

(497

2)1

00

60

(453

1)1

00

60

(437

)11

1

60

(457

1)1

00

60

(437

)11

0

60

(442

3)

60

(445

9)

60

(494

2)6

60

(437

)10

4

60

(443

9)

60

(455

)10

0

60

(438

3)1

01

60

(494

2)4

60

(444

7)

60

(434

9)1

00

60

(494

3)2

60

(437

)10

7

60

(457

8)1

03

59

(457

8)1

01

59

(457

8)1

00

60

(797

5)3

Provenance

heig

ht

(m)

BenmoreRadnorThetford

Summary – Resilient Forests

• A key ‘future concept’ in forest management is resilience

• What does it mean?

• How can it be assessed/measured?

• Is the science in place to advise policy?

• Is understanding advanced enough to develop forestry practice?

SpruceSerbian spruce: Picea ormorika Oriental spruce: Picea orientalis

RedwoodsCoast redwood: Sequoia sempervirens Wellingtonia: Sequoiadendron

giganteum

Crytomeria: Japanese cedarJapanese cedar: Cryptomeria japonica Japanese cedar: Cryptomeria japonica

CedarsAtlas cedar: Cerdus atlanticaCedar of lebanon: Cedrus libaniHimalayan cedar: Cedrus diodara

Western red Cedar: Thuja plicata Leyland cyprus: Cupressus x leylandii

European Fir’sEuropean silver fir: Abies alba Greek fir: Abies cephalonica

Old favourites!Western hemlock: Tsuga heterophylla Douglas-fir: Pseudotsuga menziesii