Forest and climate change a study how world A Presentation by Mr Allah Dad Khan Consultant NRM IUCN Pakistan

2. Forest and Climate Change a Study
how world affected
A Research Report
By Mr Allah Dad Khan

3. Climate change and forests are intrinsically linked. On the one
hand, changes in global climate are already stressing forests
through higher mean annual temperatures, altered
precipitation patterns and more frequent and extreme
weather events. At the same time, forests and the wood they
produce trap and store carbon dioxide, playing a major role in
mitigating climate change. And on the flip side of the coin,
when destroyed or over-harvested and burned, forests can
become sources of the greenhouse gas, carbon dioxide.
Climate Change

4. Different species react differently to changes in climatic conditions.
Some forest species will benefit from global warming in the long
term, while other species may decline over time. The decline of
individual species may be due to changes in the physiology or
geographic range of the species or in the structure of biological
communities. The earlier arrival of the spring may also change the
rhythm of biological phenomena.
Changes in seasonal rhythms and the temporal distribution of
biological activity may damage interaction between pollinators and
plants, for example. Many of the rare species of insects found in
Finland are fully dependent on the prevalence of a specific plant and
the timing of blooms.
Forest species

5. Impacts on forests arise from increases in atmospheric
CO2 concentration, changes in temperature regimes, and
variations in annual rainfall patterns. Such shifts could alter basic
physiological processes in trees and soils, influencing growth and
the yield of commercial products over time. The actual time
pattern of change will be complex, owing to lags between
atmospheric changes, climate effects, and biological responses.
Forest Impact

6. 1.Many aspects related to climate change are likely to affect forest
growth and productivity. Three examples are described below:
increases in temperature, changes in precipitation, and increases
in carbon dioxide (CO2).
2. Productivity refers to the rate of biomass (organic matter) produced
by an individual organism or a community, measured as either energy
or organic matter produced per unit area. Plants use the energy from
sunlight to convert atmospheric CO2 and water to organic sugars
through photosynthesis. Plants “fix” carbon when they convert it
from an inorganic form (e.g., CO2) to an organic form (e.g., glucose).
Impacts on Forest Growth and Productivity
Productivity

7.  Although scientists predict an increase in precipitation due to
climate change, it will likely not be sufficient to keep up with
increased evaporation from rising summer temperatures. This
will lead to decreased soil moisture, which will cause more
drought-resistant trees or grasslands to displace existing forest
ecosystems.
 If climate warming continues, the proportion of the coniferous
forests will decline and the proportion of broad-leaved forests
will increase
Impacts on Forest Growth and Productivity
Alert in stream flow

8.  Warming temperatures generally increase the length of the
growing season. It also shifts the geographic ranges of
some tree species. Habitats of some types of trees are
likely to move north or to higher altitudes. Other species will
be at risk locally or regionally if conditions in their current
geographic ranges are no longer suitable.[2] For example,
species that currently exist only on mountaintops in some
regions may die out as the climate warms since they
cannot shift to a higher altitude.
Impacts on Forest Growth and Productivity
Increase air and stream temperature

9. Climate change will likely increase the risk of drought in some
areas and the risk of extreme precipitation and flooding in others.
Increased temperatures alter the timing of snowmelt, affecting the
seasonal availability of water. Although many trees are resilient to
some degree of drought, increases in temperature could make
future droughts more damaging than those experienced in the
past.
In addition, drought increases wildfire risk, since dry trees and
shrubs provide fuel to fires. Drought also reduces trees' ability to
produce sap, which protects them from destructive insects such as
pine beetle.
Impacts on Forest Growth and Productivity
Intensified drought

10.  Carbon dioxide is required for photosynthesis, the process
by which green plants use sunlight to grow. Given sufficient
water and nutrients, increases in atmospheric CO2 may
enable trees to be more productive, which may change the
distribution of tree species. Growth will be highest in
nutrient-rich soils with no water limitation, and will decrease
with decreasing fertility and water supply
Impacts on Forest Growth and Productivity

11. Insect outbreaks often defoliate, weaken, and kill trees. For example, by 2007,
pine beetles had damaged more than 650,000 acres of forest in Colorado and
spruce beetles had damaged more than 3.7 million acres in southern Alaska
and western Canada.The hemlock woolly adelgid, an invasive species that is
sensitive to cold weather and destroys Eastern hemlock, will likely extend its
habitat north as the climate warms.A lack of natural controls, such as predators
or pathogens, as well as inadequate defenses in trees, can allow insects to
spread.
Climate change could contribute to an increase in the severity of future insect
outbreaks. Rising temperatures may enable some insect species to develop
faster, alter their seasonal life cycles, and expand their ranges northward.
Invasive plant species can displace important native vegetation because the
invasive species often lack natural predators. Climate change could benefit
invasive plants that are more tolerant the environmental conditions resulting
from climate change than are native plants.
Impacts on Forest Growth and Productivity
Increased susceptibility to insects and disease

12. Infestations of the mountain pine beetle are normally controlled
by intense cold snaps in the winter, but warmer winters have
been one factor enabling the infestation to grow into an
epidemic in British Columbia's Interior forests. Over 50%
of B.C.'s commercially valuable pine timber has already been
lost due to the infestation of the mountain pine beetle
Impacts on Forest Growth and Productivity

13. Climate change could alter the frequency and intensity of
forest disturbances such as insect outbreaks, invasive species,
wildfires, and storms. These disturbances can reduce forest
productivity and change the distribution of tree species. In
some cases, forests can recover from a disturbance. In other
cases, existing species may shift their range or die out. In
these cases, the new species of vegetation that colonize the
area create a new type of forest. Warmer temperatures are
also expected to expand the ranges and enhance the survival
rates of forest pests such as the spruce budworm and the
mountain pine beetle.
Impacts on Forest Growth and Productivity

14. Increased frequency and magnitude of wildfires
In 2011, wildfires consumed more than 8 million acres of forest in
the U.S. (an area roughly the size of Maryland), causing 15 deaths
and more than $1.9 billion in damages. Warm temperatures and
drought conditions during the early summer contributed to this
event Climate change is projected to increase the extent,
intensity, and frequency of wildfires in certain areas of the
country. Warmer spring and summer temperatures, coupled with
decreases in water availability, dry out woody materials in forests
and increase the risk of wildfire. Fires can also contribute to
climate change, since they can cause rapid, large releases of
carbon dioxide to the atmosphere.
Impacts on Forest Growth and Productivity

15. Climate impact on forest Hurricanes, ice storms, and wind
storms can cause damage to forests. Hurricanes Rita and
Katrina in 2005 damaged a total of 5,500 acres of forest. The
amount of carbon released by these trees as they decay is
roughly equivalent to the net amount of carbon sequestered
by all U.S. forests in a single year
Reduced Snowpack

16.  Globally, it is estimated that only about half of the forests
that were present 8,000 years ago still remain on Earth. A
large portion of forest loss has occurred within the last 300
years, with conversion to other land uses such as
agriculture and settlements.
 Global changes in climate are having a significant impact
on forested ecosystems, causing increases in tree mortality
rates, and decreases in tree growth and health. Besides
changes in temperature and rainfall, climate change
projections for Australia indicate an increase in the
frequency and intensity of extreme climatic events.
Forest ecosystem

17. Climate exerts control over vegetation directly and indirectly via changes in the
physical environment that affect the cycling of carbon, water, and nutrients
between plants and soils. Forest physiology, competitive interactions, and
disturbance regimes may be altered as a result of climate change
Woodlands and forests contain substantial carbon (C) in the soil, trees and
other vegetation, and globally they are hugely important to the carbon, water
and energy cycles. Removing forests releases CO2 into the atmosphere, while
growing trees absorb CO2 from the air. Other greenhouse gases (GHG) such
as methane and nitrous oxide are also exchanged between forests and the
atmosphere, so forests are a key component of the planet’s GHG balance.
Therefore the functioning and management of forests are critical to efforts to
reduce climate change (‘climate change mitigation’), and reduce the net GHG
emissions into the atmosphere (‘emissions abatement’).
Climate and vegetation