EcophysiologyAsad Noman Roll No: 111 BS Botany 8th (SS)

Ecophysiology

 

Environmental physiology or physiological ecology is a biological discipline that studies the adaptation of an organisms  physiology to

environmental conditions.

The study of the physiology of organisms with respect to their adaptation to the environment

Physiological Ecology

Two themes:

1. Homeostasis – maintenance of constant internal conditions in varying environments

2. Adaptation of organisms to specific environments.

Three big problems

1. Obtaining energy and nutrients

2. Maintaining temperature

3. Obtaining and holding onto water

FACTORS THAT EFFECT PLANT

• Light

• Temperature 

• Water (HUMIDITY)

• Nutrition

LIGHTLight has three principal characteristics that affect plant growth.

•Quantity

•Quality

•Duration

Plant Adaptation to the Light Environment

Two types of adaptions maked by plants

• Adaptations to control light absorption capacity(Long-Term Light Adaptations).

• Adaptations to deal with the light energy, which has been captured(short-term adaptations ).

Temperature

Temperature affects the growth and productivity of plants, depending on whether the plant is a warm season or cool season crop.

• Photosynthesis.

• Temperature influence on growth.

Plant Adaptation To Temperature

High Temperature

• Transpiration.• Production of Heat shock

proteins.• Change in Membrane

structure and composition.

Low Temperature

• Accumulation of solutes by the cells

•  Antifreeze Protien• Synthesises of proteins

 “dehydrins”.• Plant cells can alter lipid

composition.

WaterThere are three potential situations with water.

• Too much.

•Too little.

•Just enough.

The Desert(Xerophytes)Desert Plant Adaptations

•  store water in their stems or leaves.• no leaves or small seasonal leaves that only grow after it

rains.• Long root systems.• Leaves with hair help shade the plant, reducing water

loss.• Waxy coating on stems and leaves help reduce water

loss.• lower growing requires less energy.

 It has spines rather than leaves and it stores water in its stem.

This plant has a waxy coating on its leaves.

Aquatic plants(Hydrophytes)

Plant Adaptations in Water

• Underwater leaves and stems are flexible .• Submerged plants lack strong water transport system.• Roots and root hairs reduced or absent.• Some plants have leaves that float on top of the water.• Chlorophyll is restricted to upper surface of leaves.• Some plants produce seeds that can float.

Chlorophyll is restricted to the upper surface

Aquatic plants must be flexible to withstand the pressures of moving water.

Plants in Cold Climates• Waxy leaves / needles.• Shed their leaves.• Plants are covered with hair.• Plants grow in clumps for protection.• Plants have dish-like flowers that follow the sun.• Plants are small - usually less than 12 inches

tall to avoid wind.• Plants are dark - helps them absorb solar heat.

http://www.arctic.uoguelph.ca/cpl/sightssounds/Org_stills/PSB9body.htm