Climate Change Threats to Plant Diversity

Climate Change
Threats to Plant
Diversity
A REVIEW PAPER
Thuiller, W. et al. 2005. Climate
change threats to plant
diversity in Europe.
PNAS: 8245–8250
By: Juan M. Rico Garcia
Background
○
○
Recent and accelerated climate change is
already having effects on a wide variety of
organisms.
Hughes (2000) established that anomalous
climate in the past half-century affects
physiology, distribution, and phenology of
species.
Scientific Reminder
○ Diffenbaugh & Field
(2013)
○ “Combination of high
climate-change
velocity and
multidimensional
human fragmentation
will present terrestrial
ecosystems with an
environment that is
unprecedented in
recent evolutionary
history.”
Diffenbaugh & Field (2013). Changes in Ecologically Critical Terrestrial Climate Conditions. Science 341:486-492
Background
○
Basic Premise of Thuiller et al. (2005);
Although previous studies modeled species
distribution and extrapolated some species to
suffer from alarming extinction risks in the
next century, only a “few studies […]
considered the consequences of multiple
climate scenarios.”*
Methods
○ Thuiller et al. used:
○ Four representative “future climate” scenarios*
○ Three different climate models (HadCM3, CGCM2,
and CSIRO2)
○ A range of niche-based modeling techniques
implemented in BIOMOD ***
○ Developed predictions of the potential
consequences for 1,350 plant species in
Europe.
Methods
○ Using flora samples (1972-1992) narrowed down
from 2294 -> 1350 plant species in Europe.
○ Climate Data (from Climatic Research Unit)
included mean annual, winter, and summer
precipitation, mean annual temperature and
minimum temperature of the coldest months,
growing degree days (>5°) and an index of
moisture availability. Totalled 7 factors.*
○ Future projections were derived using climate
model outputs from the I.P.C.C
*
2001 I.P.C.C. Future Projections
Climate Change 2001: Impacts, Adaptation, and Vulnerability: Contribution of Working Group II to the Third Asssessment Report of the IPCC
2001 I.P.C.C.
Carbon Dioxide
Projections only
Credit: Robert A. Rohde / Global Warming Art
Methods
○ BIOMOD Framework:
● Uses a variety of niche-based
modelling techniques:
◆ Generalized linear models
◆ Generalized additive models
◆ Classification tree analysis
◆ Artificial Neural networks
Methods
○ For each climate change scenario,
models relating species distribution to the
seven bioclimatic variables were fitted by
using BIOMOD and projecting into future
○ Two contrasting assumptions about
migration ability were made*
Methods
○ Evaluated species extinction risks*
○ Assigned each species to a IUCN
(International Union for Conservation
of Nature and Natural Resources)
threat category.
Results
Results
No Migration
○ More than half the
species become
vulnerable or
committed to
extinction by 2080.
○ A1-HadCM3: 22%
were critically
endangered (80%
range loss) and 2%
extinct by 2080
Full Migration
○ Less severe
○ tA1-HadCM3: 67%
of species
classified low-risk
○ tB1-HadCM3: 76%
of species would
be at low risk.
Ecosystem relevance
○ Niche-based modelling does not
address proximate causes of species
extinction.
○ However, any reduction in potential
geographic ranges of species will
increase risk of local extinction.
➢ Rationale behind the IUCN
Ecosystem relevance
Vortex Depiction Credit
Percentage of Species loss &
Percentage of species turnover
Results
A1-HadCM3
B1-HadCM3
○ Mean European temp ○ Mean European
increases ~4.4K
temp increases 2.7
○ Mean species loss of
K
42% and turnover of ○ Lowest CO
2
63%
increase
○ Had the Widest range
○ Lowest expected
of variability:
mean percent
2.5-86% Species Loss
species loss (27%)
22-90% Turnover*
Other scenarios show intermediate mean rates of species
loss (~30%) and turnover (~50%)
Percentage of Species Loss:
Contrast between Moisture and
Growing-Degree Days
Regional Deviations
Spatial Sensitivity by biogeographic
regions
Conclusions & A Global Context
IN general, a proportion of European plant
species could become vulnerable within the next
80 years.
○ The relationship between species loss and
changes in bioclimatic variables, implies that
action to reduce greenhouse gasses may
mitigate climate-change effects in plant diversity
○ Even under the most conservative scenario, the
risks to biodiversity appear to be considerable.
○ Different regions will respond differently to
climate change.
○
A larger social and economic context
○
○
Appeal to the romanticist ideas of beauty in
nature; John Muir
Appeal to Ecosystem services:
Schröter, et al. (2005): decreasing supply of
ecosystem services, especially in the
Mediterranean and mountain regions.
○ Declining soil fertility
○ Declining water availability
○ Increasing risk of forest fires and stochastic
events
○ Decrease in pollution breakdown and absorption
○
○
Appeal to Reason
A larger social and economic context
○
The Economics of Ecosystems and
Biodiversity (TEEB) (backed by the UN and
various European governments) estimate:
●
●
●
●
●
Pharmaceutical; US $640 bn. (2006)
Biotechnology; US $70 bn.* (2006)
Personal care products: US $22 bn. (2006)
Herbal supplements: US $12 bn. (2006)
Food Products: US $31 bn. (2006)
*from public companies alone
Limitations
○ A continuous theme of limitations:
- Authors did not assess impacts of
land-use land cover change
- Limited range size
- Did not take into account stochastic
events.
- Had a simplistic view of migration
- Uncertainties in modelling
techniques used.
An Update to the
Story
Thuiller, W. et al. 2011.
Consequences of climate change
on the tree of life in Europe. Nature
DOI:10.1038
Take Home Message
○ Biodiversity, appears to in considerable risk
as a result of climate change patterns.
○ As different regions change in composition,
we will have to see how environments adjust
and subsequently change.
○ Plant biodiversity, along with biodiversity in
general, has a multitude of beneficial facets
that may be altered and diminished due to
the changing climate conditions.
Do we have time?
Thank You for Listening to
the Presentation
Any questions?
No, right?
Literature Cited
Diffenbaugh, N. S., & Field, C. B. (2013). Changes in ecologically critical terrestrial climate conditions.
Science, 341(6145), 486-492.
Hughes, L. (2000). Biological consequences of global warming: is the signal already apparent?. Trends
in Ecology & Evolution, 15(2), 56-61.
Schröter, D., Cramer, W., Leemans, R., Prentice, I. C., Araújo, M. B., Arnell, N. W., ... & Zierl, B. (2005).
Ecosystem service supply and vulnerability to global change in Europe. Science, 310(5752), 13331337.
Thuiller, W., Lavorel, S., Araújo, M. B., Sykes, M. T., & Prentice, I. C. (2005). Climate change threats to
plant diversity in Europe. Proceedings of the National Academy of Sciences of the united States of
America, 102(23), 8245-8250.
Thuiller, W., Lavergne, S., Roquet, C., Boulangeat, I., Lafourcade, B., & Araujo, M. B. (2011).
Consequences of climate change on the tree of life in Europe. Nature, 470(7335), 531-534.
Trenberth, K. E. (2001). Stronger evidence of human influences on climate: The 2001 IPCC
Assessment. Environment: Science and Policy for Sustainable Development, 43(4), 8-19.
Climate Change
Threats to Plant
Diversity
A REVIEW PAPER
Thuiller, W. et al. 2005. Climate
change threats to plant
diversity in Europe.
PNAS: 8245–8250
By: Juan M. Rico Garcia