From landscape to individuals: forest dynamics under global change

From landscape to individuals: forest dynamics under global change

Aitor Ameztegui CREAF - CTFC

Lleida, 5 December 2016

Politicians Discussing Global Warming Isaac Cordal, Berlin

Effectsofclimatechangeonforestecosystems?

Adapted from Hughes (2000)

Canwealreadyobservechangesinforestecosystems?

Hódar&Zamora2004

Peñuelas2000

Photo:P.Ezpela

Canwealreadyobservechangesinforestecosystems?

Predictionsinspeciesdistributions

Hanewinkel et al. 2013, Nature Clim Cha

Theurillat & Guisan, 2001, Clim Cha

Predictionsinspeciesdistributions

Observedchangesinspeciesdistributions

Peñuelas & Boada, 2003, Glob. Cha. Biol



Palombo et al, 2013, Plant Bios.



Palombo et al, 2013, Plant Bios.Beckage et al, 2008, PNAS

Hättenschwiler & Körner, 1995


Lenoir et al, 2010, Ecography



Lenoir et al, 2010, Ecography



Why?

climate change is just part of the story

climate change is just part of the story

GLOBAL

Climate change

Climate change

Nitrogen deposition

Climate change

Nitrogen deposition

Land-usechanges

Climate change

Nitrogen deposition

Land-usechanges

AtmosphericCO2

Climate change

Nitrogen deposition

Land-usechanges

AtmosphericCO2

Biotic exchanges(inv. species)

Importanceofcomponentsofglobalchange

http://earthenginepartners.appspot.com/science-2013-global-forest?hl=es&llbox=10.12%2C-19.17%2C-31.9%2C-74.66&t=ROADMAP&layers=layer0%2C10%3A100%2Clayer9%3A100%2C6%2Clayer12%2C2%3A100

http://earthenginepartners.appspot.com/science-2013-global-forest?hl=es&llbox=-20.743%2C-24.174%2C-57.773%2C-63.118&t=ROADMAP&layers=layer0%2C10%3A100%2Clayer9%3A100%2C6%2Clayer12%2C2%3A100

Importanceofcomponentsofglobalchange

Sala et al. (2000). Science

http://earthenginepartners.appspot.com/science-2013-global-forest?hl=es&llbox=10.12%2C-19.17%2C-31.9%2C-74.66&t=ROADMAP&layers=layer0%2C10%3A100%2Clayer9%3A100%2C6%2Clayer12%2C2%3A100

http://earthenginepartners.appspot.com/science-2013-global-forest?hl=es&llbox=-20.743%2C-24.174%2C-57.773%2C-63.118&t=ROADMAP&layers=layer0%2C10%3A100%2Clayer9%3A100%2C6%2Clayer12%2C2%3A100

ForestcoverinSpain1900-2010

Forestexpansion:whatiscausingit?

Sala et al. (2000). Science

Pinus uncinata = (P. mugo ssp. uncinata) 65.000 ha.

ForestexpansioninthePyrenees

Ameztegui et al. 2010, Glob. Ecol. Biog Photo Credit: Lluís Coll


Ameztegui et al. 2010, Glob. Ecol. Biog


P. uncinata in 1956 Encroached areas


Surface (ha) FCC (%)1956 55.196 31,22006 64.074 (+15%) 55,6


P. uncinata in 1956 Encroached areas


ALTITUDE vs COLONIZ ALTITUDE vs DENSIF

ALTITUDE vs COLONIZ ALTITUDE vs DENSIF

Shade index (º)0 20 40 60 80 100 120 140 160 180

Prob

abili

ty

0,0

0,2

0,4

0,6

0,8

1,0**

Altitude (m)1400 1600 1800 2000 2200 2400

Prob

abili

ty

0,0

0,2

0,4

0,6

0,8

1,0

**


Ameztegui et al. 2010, Glob. Ecol. BiogGrasslands (%)

0 20 40 60 80

Prob

abili

ty

0,0

0,2

0,4

0,6

0,8

1,0

*

Population change (%)50 100 150 200

Prob

abili

ty

0,0

0,2

0,4

0,6

0,8

1,0

*

“Forests occupy the land on which the plow can not go”


Pliny the Elder (AD 23 – AD 79)

Traditionalland-usesinEuropeanmountains

Traditionalland-usesinEuropeanmountains


Molina (2002)


Molina (2002)

Reductionofpressureonforest

Abandonmentofintermediateslopes

Intensificationofbottom-valleyexploitations


Molina (2002)

Molina (2002)

Reductionofpressureonforest

Abandonmentofintermediateslopes

Intensificationofbottom-valleyexploitations


Photo Credit: Lluís Coll

Does not mean there is no role of climate

Does not mean there is no upward spread

Ameztegui et al. In prep

Ameztegui et al. In prepPN Aigüestortes i Estany de Sant Maurici


Total Forest

Closed Forest

FCC (%)

1956 9,000 ha 8,100 ha 54,32006 9,200 ha 8,950 ha 62,8Change +2% +10%

Importanceofland-usechangesinEuropeanmountains

Consequencesofforestexpansion

Photo: M. Beltran

Surface (ha) FCC (%)1956 55.196 31,22006 64.074 (+15%) 55,6


Photo: M. Beltran

Climatechange

Sohowcanwemanagethis?

Sohowcanwemanagethis?Experience on its own is an adequate basis for predicting the future if the future is exactly like, or very similar to, the past. This is generally not the case. This is bit like driving a car slowly down a freeway with the front windshield covered. One can navigate safely looking only in the rear-view mirror because the future direction of the road is changing slowly relative to the past direction and one’s speed. The knowledge gained from the rear view mirror (experience of the past) will show you when you start to go off the road in sufficient time for a course correction. But such a navigational procedure is not appropriate for driving on a winding mountain road where the future changes rapidly and unpredictably relative to the past. In such cases excessive reliance on experience will probably result in your vehicle going off the road

Hamish KimminsUBC


We need to anticipate future conditions

Hamish KimminsUBC


We need to anticipate future conditions

Hamish KimminsUBC

MODELS

Statistical models that relate the current distribution of species and ecosystems to climate variables

Typesofmodels

1

Process models based on ecophysiology2

Typesofmodels

Population models that incorporate the effects of climate on the demography of species3Typesofmodels


• Each species responds individually



• Competition, interactions




• Same scale as management




• Same scale as management

• Easier to parameterize


• Parameterization time-consuming


• Parameterization time-consuming

• Computationally exigent

P. uncinata

P. sylvestris

A. alba

OK,let’smodel!Whatdoweneed?

Datarequirements

Allometry & resources Growth

Mortality Dispersal & recruitment

Climate change

Garbage In ————> Garbage Out

Garbage In ————> Garbage Out

Your analysis is as good as your data

Modified from Loehle (2000)

Fundamental niche differentiation

Whittaker (1975)



Whittaker (1975)

Shifting competitive hierarchy Keddy (1989)



Whittaker (1975)


Continuum concept Austin and Smith (1990)



Whittaker (1975)


“Species are often limited by physical stresses at one margin, but by biotic interactions at the other, more favorable, margin of their distribution along environmental gradient” (Lenoir, 2010)




Whittaker (1975)


“Species are often limited by physical stresses at one margin, but by biotic interactions at the other, more favorable, margin of their distribution along environmental gradient” (Lenoir, 2010)


Species-specific effects of climate

Allometry & resources Growth

Mortality Dispersal & recruitment

Climate change

OK,let’smodel!Whatdoweneed?

Effectofclimateondemography(1):adultgrowth

Gomez-Aparicio et al. 2011

Canham & Murphy, 2016, Ecosphere

Effectofclimateondemography(2):adultmortality

Ruiz-Benito et al. 2013

Effectofclimateongrowth&mortality

Adapted from Gomez-Aparicio et al, 2011, Glob Ecol Biog

Adapted from Ruiz-Benito et al. 2013, PLoS One


Adapted from Gomez-Aparicio et al, 2011, Glob Ecol Biog

Adapted from Ruiz-Benito et al. 2013, PLoS One


Adapted from Gomez-Aparicio et al, 2011, Glob Ecol BiogJuvenile growth

and mortality

P. sylvestris P. uncinataA. alba

Effectsofclimatechange:spacefortimeapproachx6

Subalpinebelt(2000m) ↓Temperatures ↑Precipitations ↑Snowcover ↓Growingseason

P. sylvestris P. uncinataA. alba

Effectsofclimatechange:spacefortimeapproach

Montanebelt(1500m) ↑Temperatures ↓Precipitations ↓Snowcover ↑Growingseason

x6

Effectofclimateonjuvenilemortality

Ameztegui & Coll, 2013 For. Ecol. Manag.

Survival period (months)

Acc

umul

ated

sur

viva

l

0 9 15 21 27 33 39

0.5

0.6

0.7

0.8

0.9

1.0

Pinus sylvestris

P < 0.001 (log-rank)

Survival period (months)0 9 15 21 27 33 39

Acc

umul

ated

sur

viva

l

0.5

0.6

0.7

0.8

0.9

1.0

Abies alba

P = 0.044 (log-rank)

Survival period (months)

Acc

umul

ated

sur

viva

l

Date vs Am Date vs As

Pinus uncinata

0 9 15 21 27 33 39

0.5

0.6

0.7

0.8

0.9

1.0

Date vs Am Date vs As

P = 0.214 (log-rank)

Effectofclimateonjuvenilemortality


EffectofclimateonjuvenilegrowthRelative height growth

Montane Subalpine Difference

0.381 0.305 -19.9% ***

0.289 0.232 -19.7%***

0.207 0.160 -22.7%***

0.283 0.276 -2.4% n.s.

Betula pendula

Pinus sylvestris

Abies alba

Pinus uncinata


Effectofclimateonjuvenilegrowth

Differences in growth match differences in growing period between sites (20%)

Relative height growth


0.381 0.305 -19.9% ***

0.289 0.232 -19.7%***

0.207 0.160 -22.7%***

0.283 0.276 -2.4% n.s.

Betula pendula

Pinus sylvestris

Abies alba

Pinus uncinata






0.381 0.305 -19.9% ***

0.289 0.232 -19.7%***

0.207 0.160 -22.7%***

0.283 0.276 -2.4% n.s.

Betula pendula

Pinus sylvestris

Abies alba

Pinus uncinata

P. uncinata is unresponsive to elevation


Effectofclimateonjuvenilegrowth&mortality

Modified from Loehle, 2000, Can J For Res

So:whatcanweexpect?

P. uncinata

P. sylvestris

A. alba

So:whatcanweexpect?

Not the same factor for upper and lower limits (temperatures vs. competition, drought)

Subalpine species unlikely to decline (restrict upward migration, species interactions)

P. uncinata

P. sylvestris

A. alba

??

Vegetation may not migrate as an entity, but changes in community composition and species interactions should be expected

So:whatcanweexpect?



P. uncinata

P. sylvestris

A. alba

??

Vegetation may not migrate as an entity, but changes in community composition and species interactions should be expected

So:whatcanweexpect?



P. uncinata

P. sylvestris

A. alba

Model of forest dynamics

SORTIE-ND:individual-basedmodelofforestdynamics

SORTIE-ND:individual-basedmodelofforestdynamics

JABOWA (Botkin et al. 1972)

SORTIE (Pacala et al, 1993, 1996)

FORET (Shugar and West, 1977)

SORTIE-ND: spatially-explicit, individually-based model

Lines, 2012

Ini$alcondi$ons:juvenilegrowth

P.uncinata–P.sylvestris(ecologicallysimilar)

P.uncinata–A.alba(moreshade-tolerantfir)

+10% +25% +50%

+10% +25% +50%

-10% -25% -50%

Results:juvenilegrowth

Increases in growth can lead to higher presence of P. sylvestris and species substitution

Results:juvenilegrowth

Ameztegui, Coll & Messier, 2015

Increases in growth can lead to higher presence of P. sylvestris and species substitution

Results:juvenilegrowthandinitialcomposition

In the case of an ecotone with ecologically different species, increases in growth do not represent a change in final composition

Whatcanwedowhenweknowourspecies?

Pinus sylvestris(Scots pine)


How much?


Pinus sylvestris(Scots pine)

Humid Mesic Xeric

0

1000

2000

3000

4000

0

1000

2000

3000

4000

0

1000

2000

3000

4000

0

1000

2000

3000

4000

0

1000

2000

3000

4000

0

1000

2000

3000

4000

0

1000

2000

3000

4000

0

1000

2000

3000

4000

0010

2030

4050

6070

CD

0−5

CD

5−10

CD

10−1

5

CD

15−2

0

CD

20−2

5

CD

25−3

0

CD

30−3

5

CD

35−4

0

CD

40−4

5

CD

45−5

0

CD

50−5

5

CD

55−6

0

CD

0−5

CD

5−10

CD

10−1

5

CD

15−2

0

CD

20−2

5

CD

25−3

0

CD

30−3

5

CD

35−4

0

CD

40−4

5

CD

45−5

0

CD

50−5

5

CD

55−6

0

CD

0−5

CD

5−10

CD

10−1

5

CD

15−2

0

CD

20−2

5

CD

25−3

0

CD

30−3

5

CD

35−4

0

CD

40−4

5

CD

45−5

0

CD

50−5

5

CD

55−6

0

CD

Stem

s · h

a

NoCC CCB2 CCA2

20

40

60

20

40

60

20

40

60

PlotAPlotB

PlotC

0 25 50 75 100 0 25 50 75 100 0 25 50 75 100Year

Basa

l Are

a (m

2·ha−1

)

Intensity0010203040506070

TypeLow

Take-homemessages

In Mediterranean mountains, land-use changes cannot be forgotten when assessing the effects of global change on forest dynamics

Before modelling, we need to know our species, which factors are affecting them and in which direction

The effects of climate change will be defined by species-specific responses and by interspecific competitive relationships

Species combinations and current structure are important, since responses are not the same if competitors are ecologically similar (Pines) or if they have different requirements

Take-homemessages

In Mediterranean mountains, land-use changes cannot be forgotten when assessing the effects of global change on forest dynamics

Before modelling, we need to know our species, which factors are affecting them and in which direction

The effects of climate change will be defined by species-specific responses and by interspecific competitive relationships

Species combinations and current structure are important, since responses are not the same if competitors are ecologically similar (Pines) or if they have different requirements

Importance of explicitly considering land-use changes and biotic interactions when

modelling climate change

Thank you!

[email protected] @multivac42

From landscape to individuals: forest dynamics under global change

Education

Transcript of From landscape to individuals: forest dynamics under global change