Climate change is causing various environmental stresses that impair plant growth, such as drought, high temperatures, and soil salinization. These stresses trigger responses in plant processes, gene expression, cellular metabolism, growth, and productivity. Changes in climate are also altering species distributions, life cycles, and interactions between species. Both direct impacts on individual species and indirect impacts through species interactions must be considered when predicting how plants will respond to climate change. Immediate action is needed to limit global warming and mitigate its effects on plants and ecosystems.

1. Presented to
Dr.Madhuleti
Presented by
K.Venkatkiran reddy
PhD. (Ag.)
Direct and indirect effect of climate
Change on plant processes
Department of Agronomy
Professor Jayashankar Telangana state Agricultural
University, Telangana
Course No. PP 605

2. Climate change definition,
• A long-term change in the earth's climate,
especially a change due to an increase in the
average atmospheric temperature.

3. • Changes in climate bring about environmental
abiotic stresses that severely impair plant growth
and productivity worldwide.
• Some examples of environmental stresses
brought about by climate change are drought,
high temperatures, soil salinization, flooding, acid
rain, high levels of CO2 in the atmosphere, etc.
• Environmental abiotic stresses severely impair
plant growth and productivity triggering a wide
variety of plant responses, ranging from altered
plant processes, gene expression and cellular
metabolism to changes in growth and
productivity

4. Climate change is likely to affect the infectious
disease burden from exposure to pathogens in
water used for drinking and recreation
• Climate change is already having a significant
impact on ecosystems, economies and
communities.
• Some regions will experience more extreme
heat while others may cool slightly.
• Flooding, drought and intense summer heat
could result.

5. Drought to climate change

6. • Climate change directly affects species by
altering their physical environment and
indirectly affects species by altering
interspecific interactions such as predation and
competition.
• The global meltdown of ice sheets and alpine
glaciers represents another, taking an
immense toll on Arctic ecosystems.

7. • Vegetation change contributed more to future
total burned area
Pine tree representing an elevational tree-
limit rise of 105 m over the period 1915–
1974. Nipfjället, Sweden

8. Alpine flora at Logan Pass, Glacier National Park, in Montana, United States:
Alpine plants are one group expected to be highly susceptible to the impacts
of climate change

9. • climatic factors such as temperature and
precipitation change.
• change in a region beyond the tolerance of a
species phenotypic plasticity, then distribution
changes of the species may be inevitable.

10. • here is already evidence that plant species are
shifting their ranges in altitude and latitude as
a response to changing regional climates.
• Yet it is difficult to predict how species ranges
will change in response to climate and
separate these changes from all the other
man-made environmental changes such as
eutrophication, acid rain and habitat
destruction

11. Recent increases in atmospheric CO2

12. • climate change is due to increase in the
concentration of CO2 (50-60%).
• The increase concentration of CO2 increases
the rate of photosynthesis where water is in
sufficient amount.
• But in drought areas the increase in
temperature decrease the level/amount of
water in soil.

13. • Increasing temperature also affects photosynthesis, With increasing
temperature, vapour pressure deficits of the air may increase, with
a concomitant increase in the transpiration rate from plant
canopies.
• However, if stomata close in response to increasing
C02concentration, or if there is a reduction in the diurnal
temperature range, then transpiration rates may even decrease.
• Soil organic matter decomposition rates are likely to be stimulated
by higher temperatures, so that nutrients can be more readily
mineralised and made available to plants.
• This is likely to increase photosynthetic carbon gain in nutrient-
limited systems.
• All the factors listed above interact strongly so that, for different
combinations of increases in temperature and CO(2) concentration,
and for systems in different climatic regions and primarily affected
by water or nutrient limitations, photosynthesis must be expected
to respond differently to the same climatic changes..

14. • When compared to the reported past
migration rates of plant species, the rapid
pace of current change has the potential to
not only alter species distributions, but also
render many species as unable to follow the
climate to which they are adapted

15. • The environmental conditions required by
some species, such as those in alpine regions
may disappear altogether.
• The result of these changes is likely to be a
rapid increase in extinction risk

16. • Adaptation to new conditions may also be of
great importance in the response of plants
• Predicting the extinction risk of plant species
is not easy however.
• Estimations from particular periods of rapid
climatic change in the past have shown
relatively little species extinction in some
regions, for example.
• Knowledge of how species may adapt or
persist in the face of rapid change is still
relatively limited.

17. • Changes in the suitability of a habitat for a
species drive distributional changes by not
only changing the area that a species can
physiologically tolerate, but how effectively it
can compete with other plants within this
area.
• Changes in community composition are
therefore also an expected product of climate
change

18. Climate change mechanism

23. Changes in life-cycles (phenology)
• The timing of phenological events such as
flowering are often related to environmental
variables such as temperature.
• Changing environments are therefore
expected to lead to changes in life cycle
events, and these have been recorded for
many species of plants

24. • These changes have the potential to lead to the
asynchrony between species, or to change
competition between plants.
• Flowering times in British plants for example have
changed, leading to annual plants flowering
earlier than perennials, and insect pollinated
plants flowering earlier than wind pollinated
plants; with potential ecological consequences
• A recently published study has used data
recorded by the writer and naturalist Henry David
Thoreau to confirm effects of climate change on
the phenology of some species in the area of
Concord, Massachusetts

25. Indirect effects of climate change
• All species are likely to be directly impacted by the
changes in environmental conditions discussed above,
and also indirectly through their interactions with
other species.
• While direct impacts may be easier to predict and
conceptualise, it is likely that indirect impacts are
equally important in determining the response of
plants to climate change.
• A species whose distribution changes as a direct result
of climate change may ‘invade’ the range of another
species or 'be invaded' for example, introducing a new
competitive relationship or altering other processes
such as carbon sequestration

26. • In Europe, the temperature and precipitation
effects due to climate change can indirectly
affect certain populations of people.
• The rise of temperatures and lack of
precipitation results in different river
floodplains, which reduce the populations of
people sensitive to flood risk

27. • The range of a symbiotic fungi associated
with plant roots may directly change as a
result of altered climate, resulting in a
change in the plant's distribution.
• A new grass may spread into a region,
altering the fire regime and greatly
changing the species composition.

28. • A pathogen or parasite may change its
interactions with a plant, such as a pathogenic
fungus becoming more common in an area
where rainfall increases.
• Increased temperatures may allow herbivores
to expand further into alpine regions,
significant impacting the composition of
alpine herb fields.

29. • consequences of climate change mitigation policies?
Policies to subsidies and increase biofuels production in
2008 had a number of unintended consequences.
Shifts of maize (corn) production to ethanol production
in the US were one contributor to the food price spike in
2008, with very damaging impacts on food security.
Biofuel incentives which led to the clearing of rainforest
for oil palm production could actually increase
greenhouse gas emissions with the release of carbon
dioxide from the burning of biomass and the breakdown
of soil organic matter.
Of course there are questions about how far biofuel
promotion is actually driven by concern to reduce
greenhouse emissions rather than to support particular
farming interest groups. (Koplow 2006)

31. Conclusion
• The world’s leading scientists report that to
prevent dangerous levels of global warming
governments should act to limit global
warming to less than 2ºC by taking concerted
action to reduce greenhouse gas emissions.
• The sooner we act to reduce greenhouse
gases, the less severe impacts will be.
• Now is the time to implement solutions.