fragmented tropical forests

cowyardvioletManagement

Nov 6, 2013 (3 years and 7 months ago)

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Ecological value of logged and
fragmented tropical forests

Pfeifer M, Ewers R, SAFE collaborators

Old
-
growth tropical forests in global biodiversity hotspots

Sundaland, Eastern Arc Mountains, Madagaskar, Andes

Ecological value of changed tropical forests

Myers et al. 2000

Mittermeier et al. 2004

Cultural Services


S
piritual/religious


Knowledge system


Education/Inspiration

Provisioning Services


Food /
Fiber

/ Fuel


Genetic Resources


Fresh Water

Regulating Services


Herbivory


Pollination


Climate regulation


Disease regulation


Hazard protection


Water purification

Supporting Services


Primary production


Habitat provision


Nutrient cycling


Soil retention


O
2
production


Water cycling

Forested ecosystems


goods and services

(modified from CBD, 2009)

Ecological value of changed tropical forests

Timber Production

Forest conversion to other land use

Economic value of changed tropical forests

Fishers et al. 2011

Mittermeier et al. 2004

C

D

VJR

OG2

OG3

OP1

Forest degradation and deforestation remain high in most
tropical countries
(Hansen et al. 2008, 2010)
.
Oil palms are
expanding at the cost of tropical forests
(Koh & Wilcove 2008)
.


Ecological value of changed tropical forests

Ecological value of changed tropical forests

….
accepting that it does affect biodiversity
(Sodhi et al. 2004,
Fitzherbert et al. 2008,

Koh & Wilcove, 2008
)

How does forest degradation and conversion to oil palms
affect biodiversity at plot and at landscape level ?

Ecological value of changed tropical forests

The concept of linking Environmental Diversity Surrogates
to Biodiversity
Faith & Walker 1996,
Sakar

et al. 2006

Hypothesis: Species diversity increases with
habitat complexity and heterogeneity (by
offering more potential niches)
Mac Arthur et
al. 1966,
Terborgh

1977 but see Brown 1973

Ecological value of changed tropical forests

Usefulness of Environmental Diversity Surrogates for
measuring / monitoring biodiversity has been challenged
fervently
Araujo et al. 2003; Hortal et al. 2009

Rapid
Biodiversity
Assessments

Conservation
Planning

Structural
Assessments,
e.g. via remote
sensing

Limited
Ressources

Duro et al. 2009:
Productivity, Disturbance,
Topography, Land cover

Gardner et al. 2008: Cost
-
effectiveness of biodiversity
surveys

Ecological value of changed tropical forests

OG

OP

Fragments

OG

OP

VJR

F

LFE

LF

E

D

A

C

B

The SAFE experiment

Ewers et al. 2011

Ecological value of changed tropical forests

Study objectives



Analyse forest structural complexity and its links to
processes (e.g. biomass production) and biodiversity
along land use gradient.


Quantify links using local
-
scale (e.g. tree architecture,
habitat structure) and landscape
-
scale (combination of
logging and/or fragmentation effects) variables


Project biodiversity trends under forest change in
landscape scale context

Ecological value of changed tropical forests

Land use


spatial variation across the SAFE landscape

Paper

OG

OG3

LF

VJR

B

D

F

A

E

C

OP

Fragmented &
logged

Logged

Land Use Intensity

V_30

V_log

Econ

OG3

OG

OG

OG

LF

LF

VJR

OG3

OG3

F

VJR

VJR

LF

D

F

B

C

E

C

B

D

E

E

B

A

F

C

D

A

A

Economic value of changed tropical forests

Forest structure


spatial variation across the SAFE landscape

Economic value of changed tropical forests

Forest ‘use’


spatial variation across the SAFE landscape

Economic value of changed tropical forests

Combining structure and ‘use’


land use gradient

Economic value of changed tropical forests

Calculating Effect Size as the difference between two or more
groups: Cohen’s d

Ecological value of changed tropical forests

Ecological value of changed tropical forests

Ecological value of changed tropical forests

Mean values of environmental and structural traits

Transects for Blocks

Ecological value of changed tropical forests

Mean of canopy closure
(in %) across plots.
Estimated for different
landscape categories.

Type: Virgin to Oil palm

Quality: Visual Estimate

Ecological value of changed tropical forests

Ecological value of changed tropical forests

Aboveground biomass [Mg]



Mean (
±

SE) in plots

Niiyama et al 2010

Plot size: 25 m x 25 m

per ha ~ 20 * 16 = 320 Mg

Deadwood volume across
decomposition classes [m
3
]



Mean (
±

SE) in plots

Baker et al 2007

Plot size: 25 m x 25 m

per ha ~ 20 * 16 = 320 Mg

160

320

480

Mg per ha

Ecological value of changed tropical forests

Why bother? LAI is key player in ecosystem processes (i.e.
photosynthesis): Dynamic Vegetation and Hydrological Modelling)

Ecological value of changed tropical forests

Need the data to link structure to biodiversity

http://biofrag.wordpress.com

Ecological value of logged and
fragmented tropical forests

Pfeifer M, ?, ?, ?, ?, Ewers R

modified after
Kareiva et al. 2011