Wind Types of wind Causes of wind Temperature a main cause of blowing wind Effects of wind on Vegetation Measurement of wind Advantages of winds Disadvantages of winds Effects on Pollination Effects on Fruits and seed dispersal

1. WIND
SCHOOLOF CHEMISTR
Y
UNIVERSITYOF THEPUNJAB

2. WIND
• Air in motion is called wind.
• It can circulate gases water vapors and small soil particles.
• Theaction of wind is an ecological factor.

3. TYPESOFWINDS
Therearedifferenttypesofwinds:
➢P
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➢P
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➢Localwinds
Permanentwinds:
Thwindswhichblowthroughouttheyearinaparticulardirectionoveraparticularregionare
knownaspermanentwinds.
Theyarealsoknownasprevailingorplanetarywinds.

4. PERIODIC WINDS:
Thewindswhichblow over a particular period of the year in a particular
direction over a particular area are known as periodic winds.
These ae known as seasonal Winds or Monsoons.
Monsoons blow from sea to land in one season and from land to sea in the
other.
Local winds:
Thewinds which blow over a limited area and have local significance.
e.g. Land and sea breeze.

5. CAUSESOFWINDS
• Wind is caused by the differences in the atmospheric pressure.
• When the difference in the atmospheric pressure exists ,air moves from higher to lower
pressure area.
• Wind blows from lower atmospheric pressure area to higher atmospheric pressure area

6. TEMP
E
R
ATUREA CAUSEOF WIND
• T
emperature is the main cause in the blowing of wind.
• When the earth heats up air becomes less dense and rise up and creates space.
• So, air from cooler (low temperature area) moves and fill the spaces causing the
wind to blow.

7. MEASUREMENTOFWIND
• ThewindspeedismeasuredbyAnemometer.
• Atmospheric pressure difference results in different wind speeds.(e.g. Gales 60-
90 Km/ Hr ,Storm 90-120Km/Hr and Hurricane > 120 Km/Hr.
•Wind moves the bowl in analog
Anemometerwhilefanindigitaland Of
cyclesarecountedandspeedis
Determined.

8. E
FFE
CTSOF WIND ON VEGETATION:
Winds effects may be direct and indirect.
Direct effects of wind are seen in the regions with continuous action of high velocity
winds.
There are following effects of wind:
➢Direct Effects of wind
➢Indirect Effects of wind

9. DIRECTEFFECTSOFWIND
➢Uprooting plants
➢Deformation of plants
➢Dwarfing of plants
➢Breaking of plant parts
➢Falling of flowers and fruits
➢Desiccation
➢Lodging
➢Abrasive action of particles

10. UPROOTING PLANTS
• Plants may be uprooted and blown away by the winds like storms in coastal
regionsof exposed mountain tops.
• Therefore the vegetation of these areas is largely composed of species with
prostate or stunted growth.
• They have well developed underground roots or rhizome system.

11. DEFORMATIONOFPLANTS
• Thereisacontinuousandunidirectionalwindpressureincoastalregions.
• Therefore the trees and their branches direct themselves towards the lower
side.
• Continuouswindaltersthepositionofshootspermanently.
• T
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12. DWARFING OF PLANTS:
• During the growth plant cells divide by mitosis.
• Large vacuoles are produced in the cells.
• Turgidity helps maturing cells of plants to grow at normal cells.
• The plants under the influence of drying winds cannot attain turgidity that
enable them to expand their maturing cells.
• So, many of the cell organs remain dwarf and affect the overall activity of
the plants.

13. BREAKINGOFPLANTPARTS
• Thebranches of large trees are broken are broken or entire trees are uprooted
in strong winds are hurricane.
• The soft parts of trees are broken.
• Some herbaceous plants lay down on land.
• Plants like banana are fallen on the ground winds blow away leaves and other
lighter parts of the plants.
• It reduces the overall photosynthetic capacity of the plants.

14. F
ALLING OF FLOWERSAND FR
UITS
• It is a big losscaused by the wind.
• Heavy winds throw away flowersand fruits of the trees.
• In Pakistan it heavily affects mango trees.
• A great amount of mango flowers and fruits are fallen away each year due to
wind.
• It causeshuge lossesto farmer.
• It causes about 50% loss of crop per annum.

15. DESICCATION:
• Wind causes evaporation rapidly.
• It causes desiccation in plants.
• Dry leaves are very dangerous for plants.
• Theycancausewiltingofplants.
• Desiccationcankillleavesandfruitsofplants

16. LODGING
• Winds cause flattering of herbaceous plants to the grounds.
• It is called lodging
• It takes place in herbaceous and weak stemmed plants like;
➢Grasses
➢Maize
➢Wheat
➢sugar cane

17. ABRASIVEACTIONOFPARTICLES
• Strong wind also carries sand particles.
• These particles have abrasive action on the leaves and tender branches.
• Crops grown near Sandy tracts suffer from abrasive action of wind

18. INDIRECTE
FFECTSOF WIND
➢Transpiration
➢CO2 R
eplenishment
➢Cooling
➢StressonLeaves
➢Stunted growth
➢Soil erosion
➢Dispersal of pollengrains for pollination
➢Dispersal of seeds and fruits

19. TRANSPIRATION
• Wind influences the rate of transpiration.
• Air gets saturated with water vapors and increases the transpiration.
• Wind velocity increases with height above the surface of the soil.
• Therefore large plants are more affected by high rates of transpiration than
smaller ones.

20. CARBON DIOXIDER
E
P
LENISHMENT
• Wind removes the bound layer of still air that covers the surface of the shoot.
• This prevents the diffusion of Oxygen from stomata and Carbon dioxide
towards stomata.

21. COOLING
• The epidermis of different parts of plants accumulates heat in the bounded
layer.
• Wind dissipates thisheat rapidly.
• So, wind causes cooling effects in plants.
• Similarly continuous transpiration also causes cooling effect

22. WIND STRESSON LE
AVES
• Wind increases the rate of transpiration.
• Strong winds causesheavy water loss.
• This decreases the temperature below the optimum.
• Low temperature effects the enzymes and reduces photosynthesis.
• This also affects the yield.
- About 24% for Barley crops
- About 48% in Marigold

23. STUNTEDGROWTH
• Strongwind increases transpiration rapidly.
• Theplantscannotmaintainaninternalwaterbalance.
• Therefore,theseplantssufferfromdehydration.
• Theyloseturgidity.
• Therefore, their organs become dwarf.
• Thisiscommonintreesonseacoast,Arctic,TobaccoandAlpinetimberline.

24. SOILEROSION
• Wind carry out soil particles.
• It causessoil erosion.
• Wind blows away top soil.
• T
op soil has many minerals does an large amount of minerals are lost due to
wind.

25. DISPERSALOFPOLLENGRAINSFORPOLLINATION
• Wind is also important for dispersal of pollen grains, seeds and fruits.
• In cold climates, most of the plants depend on wind for pollination.
• This wind helps in cross pollination of different varieties of species.
• Therefore a large number of verities are produced in plants.
• It increases Vigor in plants.
• This dispersal isknown asAnemophily.
• It may have certain disadvantages.
• The abundance of pollens
causes Hay fever in human

26. Dispersal of P
ollens

27. DISPE
R
SAL OF SEEDSAND FRUITS
• Mostoftheterrestrialplants depends onwindtoscatteritsdisseminules (seeds&
fruits).
• Wind disperses the seeds and fruits of plants to that far off
places (Anemochory).
• TheirSeedsaregrownintheseareasandtheystartgermination.
• Thuswindhelpsinecologicalsuccessionandnewvarietiesofplantsareestablishedinarid
areas.

28. Dispersalandgerminationofseed