Forest Resilience and Climate Change an ecological perspective

Transcription

1 Forest Resilience and Climate Change an ecological perspective October 2015 Birmingham Jonathan Spencer Head of Planning and Environment Forest Enterprise England

2 Climate Change 2

3 Pests, pathogens and global trade 3 28/09/2015 Forest Enterprise

4 Hotter and drier summers Milder and wetter winters Hot and dry insects Mild and wet fungi 4

5 We have been here before The Hoxnian and Ipswichian The here and now present interglacial and across UK The Tertiary where might end up 5

6 What happened to all our trees?? The trees and forests repeatedly scraped from face of Europe Refugia in South and south east of Europe Tertiary species lost 6

7 Some 20 ice ages and interglacials with each one reducing tree and shrub diversity, pushing trees to south and south east with major refugia in Georgia, the Carpathians and the Balkans. 7

8 And with varying conditions and duration of interglacials, with quite varied, but diminishing, forest species returning between each glaciation 8

9 Britain as was We are all Europeans now But in reality we always were Important lesson is that, with respect to future, native best interpreted as native to European forest. 9

10 Some lessons Very important to note that: Native trees are the weed trees that raced back. Are themselves of proven resilience. Are only a subset of the suite of pre Quaternary NW European temperate forest species. Have all survived in warm and dry or cold and dry refugia. 10

11 In contrast North America Geographic barriers run north south Possessed refugia that were both cold and wet the pacific NW and West 11

12 Past and present timber trees a review Present interglacial native timber trees Oak, ash, beech, cherry, hornbeam.scots pine? Past interglacial native tree species Scots pine, silver fir, Norway spruce, Serbian spruce, Tsuga.. Sycamore, Norway maple, other maples, Carya (Hickory) Caucasian wingnut. Past Tertiary natives before the ice Sequoias, Cryptomeria, Liriodendron, Cedrus, Magnolias and others * important to consider given longer term climate change scenarios? 12

13 Returning to resilience What is missing in UK is a comprehensive rationale to address resilience 13

14 Features of forest resilience Forest and stand: 1. Genetic variation 2. Species diversity 3. Stand and structural diversity Tree biology and characteristics: 1. Genetic outcrossing, fecundity 2. Phenotypic plasticity 3. Natural and vegetative regeneration and fecundity 4. Shade tolerance and 5. Interaction with other tree species and other organisms 14

15 Species characteristics examples 15 28/09/2015 Forest Enterprise

16 Forest soils and soil mycorrhizae Critically Important! 16 28/09/2015 Forest Enterprise

17 Getting changes in train Fundamentally all this means moving away from plantation forestry to more naturalistic forestry. And towards forest stands composed of more than one species, with species chosen or encouraged for compatible ecological performance across a range of ecosystem services. 17

18 So what are we considering? Climate change and forest resilience is forcing a major rethink of what is native, what is natural and what might be wise. We are looking at two models A lowland temperate western European forest model A NW American model for upland north and western England production forest model. 18

19 1.Performance and resilience Temperate Forests intermediate between tropical forests and boreal forests. Mixed species stands perform better with regard to basic productivity in capturing light, water and nutrients. The Ecotron! Species variation and genetic variation the key to disease resistance and resilience against change Natural regeneration and regrowth bolster resilience Recommendation1. we use appropriately mixed stands; accept and utilise regeneration and regrowth; and enhance stands where required in all locations AW, CCF; coppice and HF 19

20 2. Two forest ecosystem models What is absent in Europe are trees of cold wet oceanic conditions. In Europe these were squeezed out as areas were ice or continental warmer, dry refuges In N. America they survived in West to recover into North West forests Douglas Fir, Noble Fir, Sitka, Western Hemlock etc In Western Europe ecological place is occupied by oak and minor associates Recommendation 2. we adopt two models; a native Western European warm Temperate Forest Model and a North West American Cool Temperate Forest Model for upland production forests. 20

21 Policy compliant approaches? Ancient woodland past/present natural? Change in composition? New forms of traditional management? Policy debate required PAWS present and future natural? Based on existing composition and recent planting history? Restoration of process rather than composition? High forest structure? Policy debate required Existing new forests present and future natural? more naturalistic; CCF and LISS; based on lowland European and NW American forest ecosystem models as appropriate? Policy development required? Newly created forests? Future natural? Policy heavily based on CC resilience? Tertiary natives? Policy to evolve? 21

22 Proposed model for FE England Ancient woods Native woodland as directed by policy (plus natives not presently in wood) Forests South and East England: European High Forest Model (Ok/Hb; Beech/Silver Fir; in old forests and big beech woods; CCF Douglas fir and associates) Pine/birch as clearfell on podsols; pine as forest pioneer in new locations Forests in North and West England: North American High Forest Model (DF, WH, WRC Spruces, Tertiary spp where app) Newer forests and new planting Tertiary spp. Or analogs of these e.g. other Firs) 22 Species choices governed by ESC and other guidance

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