2. Biology 633 Environmental Plant Physiology Tropical rainforest Alpine tundra Desert aderfasi@yahoo.com Study of how the environment affects the function of plants

3. Module overview l Discuss interplay between the genetic potential of plants and environments in which they grow l Impact of short-term changes in the environment on physiology, morphology and growth of plants l Stress response, acclimation and adaptation of plants in response to changes in environment l 16 lectures and 4 practical sessions

4. Overview of lectures l Introduction to Environmental Plant Physiology l Response of plants to their environment l Plant growth analysis l Photosynthesis; mostly C 3 plants l C 4 and CAM plants l Respiration l Water, drought and plant growth l Adaptation of plants to growth on the sea floor

5. Recommended texts  Lambers, Chapin & Pons (1998) Plant Physiological Ecology  Atwell, Kreidemann & Turnbull (1999) Plants in Action  Fitter & Hay (1987) Environmental Physiology of Plants  Larcher (1995) Physiological Plant Ecology  Taiz & Zeiger (1991) Plant Physiology

6. Lecture 1 Learning objectives l Define Physiological Ecology l Appreciate dynamic nature of the plant/environment interaction l Be familiar with variations in environmental conditions between and within habitats l Importance of time scales in determining response of plants to their environment

7. Plants: static or dynamic?

8. Visually stunning

9. Their structures respond to changes in environment (e.g. shade)

10. Their metabolism is constantly changing response to large variations in environment

11. Temporal variation in temperature

12. …….and light intensity

13. Global environment is also changing e.g. greenhouse gases, temperature, nutrients, UV-radiation

14. Year Atmospheric CO 2 concentration (ppm) Rising atmospheric CO 2 concentrations

15. …….enormous flow of CO 2 in and out of leaves

16. …….and these are cells that remove CO 2 from the atmosphere

17. What is Environmental Plant Physiology (EPP)? l Study of how the environment affects the function of plants l Requires knowledge of biochemistry, physiology, anatomy and morphology of plants l Provides causal, mechanistic explanations for ecological questions such as: - Why does a species live where it does? - How does it survive, and why is that species absent from other environments?

18. Question: how do plants cope with excess light when it is very cold? e.g. avoid the morning sun

19. Question: how do plants cope with soils deficient in phosphorus? e.g. grow cluster roots

20. Question: how do plants cope with excessive salt? e.g. sequester salt in salt bladders

21. Question: how do plants manage to grow in deep shade? e.g. use light flecks

22. Environmental Plant Physiology & Agriculture/Forestry l EPP is also closely linked to the study of plant performance in agriculture l Agricultural production is limited in many countries by stresses such as drought, nutrient availability, salinity, temperature l Need to develop crops that are less sensitive to those stresses, so we can grow them in less favorable environments l Understanding required of the physiological mechanisms that enable plants to cope

23. Question: what mechanisms enable the barley variety on the left cope better with manganese deficiency than the variety on the right?

24. Environmental Plant Physiology & Global Change l Need to predict effect of future changes in global environment on crop productivity, competitive interactions among species etc l Also need to know the extent to which plants could reduce future increases in elevated atmospheric CO 2

25. Photo- synthesis Plant respiration Global atmospheric CO 2 concentrations: importance of plants

26. Environmental Plant Physiology & Molecular Biology l Mutants/transgenics may allow a rigorous test of hypotheses l e.g. transgenic tobacco plants to assess importance of Rubisco (CO 2 fixing enzyme in plants) for plant growth

27. Why so few plant species in one place? Filters zSome species do not occur in the UK, because they were never introduced zOthers arrived, but never made it to maturity zSome evolved locally, or were introduced and ‘made it’ zFilters are constantly changing/interacting

28. Response of plants to their environment: time scales l Time scale of physiological response is important in determining how a plant copes with changes in the environment e.g. short- and long-term changes in temperature l Stress response l Acclimation response l Adaptation/evolution response

29. Stress and acclimation (of an individual) vs. adaptation (a long-term genetic response)