Ecology - Crop adaptation to its environment - Response of plants to climate change - Recent trends of Climate change - Effects of climate change - crop adaptation strategies

1. CROP ADAPTATIONS AND ITS ECOLOGY
S. ASHOKH ARAVIND
2020602004
1ST Ph. D (AGRONOMY)

2. Carbon dioxide – 417 ppm (July 2021)
The evidence for rapid climate change is compelling:
• Global temperature rise
• Warming ocean
• Shrinking ice sheets
• Glacial retreat
• Decreased snow cover
• Sea level rise
• Declining arctic sea ice
• Extreme events
• Ocean acidification
Effects
• Temperature will continue to rise
• Frost free season & growing season will lengthen
• Change in precipitation patterns
• More drought and heat waves
• Hurricanes – stronger and intense
• Sea level rise 1-8 feet by 2100
• Arctic likely to become ice-free
Scientific evidence for warming of the climate system is unequivocal - IPCC

3. Increasing number of extreme climatic events

4. Direct, indirect and socio economic effects of climate change

5. Overall effects of climate change and global warming

6. Crop adaptations and its ecology

7. Crop adaptations
• The modifications in the structure of organisms to survive successfully
in an environment.
• Adaptations help the organisms to exist under the prevailing
ecological habitat.
• Success of a plant in a particular environment rarely depends on
possession of a single adaptive character.
• Rather, fitness or adaptation to an environment depends on
possession of an optimum combination of characters that minimizes
the deleterious effects and maximizes the advantageous effects.

8. Adaptation Needs
• India, currently a producer of about 15% of the world’s wheat crop,
might be forced to turn away from a high-yield potential, irrigated,
low rainfall mega-environment to a heat-stressed irrigated, short
season production environment because of changes in climate.
• If crop adaptation strategies are not developed and implemented,
India, the second largest (FAO, 2011) and historically self-sufficient
wheat producer, may fail to provide enough wheat to meet the needs
of its own people.

9. Adaptation strategies
• Adaptive strategies in plants can be considered as their responses to stress,
disturbance, or both.
• Stress is defined as any sub-optimal or deleterious factor(s) in the plant
environment.
• Disturbance means any disruption of the plant’s natural growth or biomass
brought about by artificial (e.g. grazing, ploughing, spraying) or natural (e.g.
erosion, frost, drought) means.
• The possible combinations of stress and disturbance create four kinds of habitats,
three of which are viable for plant survival, growth and development
Different situations
Stress intensity
low high
Disturbance
Intensity
Low Competitors Stress tolerators
high Ruderals Not viable

10. Drought with increased temperature

11. Some Crop Adaptation Mechanisms

12. Root response to increased ambient temperature
• Changes in RSA
• Metabolism
• Temperature-mediated
alteration of hormone levels
trigger signal transduction
pathways and
• other molecular responses.
• In the field, increasing
temperature is usually
accompanied with other abiotic
and biotic stresses such as
drought, salinity, nutrient
deficiency and pathogen
infections.

13. Response of root to increasing temperature
• Interestingly, these root
responses coincide with
root traits associated
with cultivars more
tolerant to high
temperatures.
• A comprehensive
evaluation of these traits
and their impact on
crops productivity will
help to decide which root
traits are more valuable
to be incorporated to
breeding programs
designed to improved
crop yield under climate
change conditions.

14. Photosynthetic Pathway as an Adaptive Mechanism
• In C3 species, rubisco has a weak affinity and hence attraction for
CO2, while in C4 species the affinity and resultant attraction of the
enzyme (PEP carboxylase) is much stronger.
• C4 plants can maintain higher rates of CO2 diffusion and
photosynthesis particularly when their stomates are partially closed
by water stress. The C4 pathway is thus an effective adaptation to
hot, dry environments and to the changing atmospheric CO2 levels.
• C3 species have low net photosynthetic rates, high CO2 compensation
levels (50-150 ppm) and high photorespiration rates.
• The C4 group, in contrast, exhibits high net photosynthetic rates, low
CO2 compensation points (0-10 ppm) and low photorespiration
rates.

15. Impacts of CO2 on Crop Quality and Nutrition
• Research shows that increased CO2 can reduce grain protein by 4 to
13% in wheat and 11 to 13% in barley, while increasing the
carbohydrates in grain.
• Depending on the crop, micronutrients also diluted by an increase in
carbohydrate in the grain. These effects are difficult to explain, and
more difficult to separate from whole plant physiological changes.
• However, they suggest that increased emphasis on research
evaluating crop composition, as well as yield, will be needed in the
coming decades.

16. Examples of Plant Adaptations
in Different Environments

17. Desert plant adaptations
Root Structure
• Structure of their roots are able to thrive with very little rainfall. Some
plants have adapted to take advantage of any rainfall that occurs
while others have adapted to look for water very deep in the ground.
• Shallow root structure - Some desert plants have shallow roots that
spread out over a wide area. This allows them to get as much
rainwater as possible during the rare occasions that it rains.
• Deep tap roots - Not all desert plants have shallow roots. Some
develop extremely long tap roots that go down very deep into the
ground. These deep tap roots are an adaptation that allows the plants
to reach water deep below the surface.

18. Leaf Waxing
• Nearly all desert plants produce a waxy coating on their leaves or
have prickly spines - help keep water from evaporating out of the
leaves - An adaptation to help prevent dehydration.
Night Blooming
• Some desert plants bloom only at night, which is an adaptation to the
extreme heat of the desert sun and certain animal adaptations.
• Preventing dehydration - Blooming-daytime-dehydrate very quickly.
Helps from losing a lot of water (dehydrating) through their blooms.
• Helping with pollination - Because many desert insects are nocturnal
(an example of an animal adaptation), -helps ensure that desert
plants get properly pollinated.

19. Reproducing Without Seeds
• While desert plants can reproduce by seeds, some don’t have to
reproduce that way.
• For example, some cacti will break off pieces of themselves. These
pieces can root and form new cacti - Since seeds require water to
sprout, there would not be as many cacti in the desert without this
adaptation.
Drought Resistance
• Desert plants have roots that can handle drying out without dying.
This adaptation is also referred to as desiccation resistance.

20. Tropical Rainforest Plant Adaptations
Leaf Size
• Plants in the lowest part of the rainforest are short and grow close to
the ground. Gets very little light - adapted to have very large leaves
to catch as much light as possible, which helps them survive.
Poisonous Parts
• An adaptation to the presence of many herbivorous animals in the
tropical rainforest. If an animal eats part of a plant - get sick or die.
Either way, the rest of the plant survives.
Brightly Colored Flowers
• The floor is dimly lit, - hard for insects to see. The brightly colored
blooms allow bees and other pollinators to easily see for pollination.

21. Plant Adaptations to Water
Resistance to Root Rot
• The roots of plants that grow in boggy conditions stay wet or damp all
the time. Plants such as ferns, cattails and swamp sunflowers, have
adapted a resistance to root rot.
Height Advantage
• Cattails - a tall wetland plant that thrives as a result of how high it
stands above the water’s surface. Typically ranging from 3 to 10 feet
in height, these tall plants thrive in muddy water.
Floating on Water
• Aquatic plants, such as water lilies, float and can thrive in muddy
water. Since their leaves float, they can easily take in light. The light
does not have to go through muddy water in order to reach the
leaves.

22. Need for the future

23. How can we adapt crops and cropping systems
to climate change?
Strategies for improving existing cultivars and developing new crops
• Develop new crops
• Integrate beneficial traits into existing crops through use of germplasm
collections, related datasets, and breeding
• Use new technologies—image-based measurements, high-throughput DNA
sequencing, databases, and statistical models
• Identify crop germplasm that tolerates drought, heat, and water-logging.
• Expand field-level evaluations of crop germplasm
• Employing new tools, techniques, and datasets to accelerate the delivery
and release of proven varieties.
• Identifying crop germplasm for tolerance to pathogens, insects, and
nematodes

24. How can we adapt crops and cropping systems
to climate change?
Strategies for developing new cropping systems that address climate
stresses
• Use crop models in decision-making
• Apply remote sensing and precision agriculture technologies
• Monitor crop condition
• Optimize water-use efficiency
• Optimize land use
In summary, new crop varieties, cropping systems, and agricultural
management strategies are needed to provide options to farmers to
counterweigh these changes.

25. Conclusion

26. References
• Calleja-Cabrera, Julian, Marta Boter, Luis Oñate-Sánchez, and M. Pernas. "Root
growth adaptation to climate change in crops." Frontiers in Plant Science 11
(2020): 544.
• Raza, Ali, Ali Razzaq, Sundas Saher Mehmood, Xiling Zou, Xuekun Zhang, Yan Lv,
and Jinsong Xu. "Impact of climate change on crops adaptation and strategies to
tackle its outcome: A review." Plants 8, no. 2 (2019): 34.
• Boote, Kenneth J., Amir MH Ibrahim, Renee Lafitte, Rebecca McCulley, Carlos
Messina, Seth C. Murray, James E. Specht et al. "Position statement on crop
adaptation to climate change." Crop Science 51, no. 6 (2011): 2337-2343.
• Kelleher, Frank. "Crop adaptation." Principles of field crop production (2003): 78-
158.
• https://climate.nasa.gov/effects/
• https://examples.yourdictionary.com/examples-of-plant-adaptations-in-different-
environments.html