AGR 519CROP PHYSIOLOGY

CANOPY ARCHITECTURE AND LIGHT PENETRATION

PREPARED BY:1. ISHAM SAMEER BIN MD YUSOF 20118351222. MUHAMMAD ZHARIF BIN ABU 20116506623. NURLIYANA BINTI RAHMAT 20112282364. NOR SYAFIQAH BINTI SUBED 2011207276

PREPARED FOR: MISS ADIB NAFISAH BINTI JAMIRAN

CANOPY ARCHITECTURE

CANOPY DEFINITION• The top layer of a forest or wooded

ecosystem consisting of overlapping leaves and branches of trees, shrubs, or both.

• Canopy is a habitat for many kind of animals. 

• All species of the plants and animals are evolve to adapt with the environment.

• Canopy is important to the soil and its component

FUNCTIONS OF CANOPY

• Influence the sexual reproduction of trees.

• Provide unique habitat for wildlife and other biota.

• Affect temperature and primary production of aquatic habitat by shading.

• Prevent extreme soil erosion by decrease the impact of rainfall which is the canopy raindrop take 5 to 10 minutes to reach forest floor.

CANOPY LAYER

OVERSTORY LAYER

• Also called emergent layer.

• Consists of giant emergent trees that tower above the surrounding canopy.

• The air is much drier and moderately strong winds blow through their branches.

CHARACTERISTICS• Trees are huge• A height of 213 feet (65 m) with

horizontal limbs that stretch over 100 feet (30 m).

• Often covered with epiphytes (non-parasitic plants which take no nutrients from the host plant but use it for support)

• Example lichens, mosses, liverworts, and algae.

• The most successful and most plentiful predators of vertebrates in the canopy are the birds of prey, such as eagles.

CANOPY LAYER

• Found directly beneath the overstory layer (emergent layer).

• The primary life sustaining layer with an abundance of food and forms a natural roof over the remaining two layers beneath.

CHARACTERISTICS• Canopy rising to 150 feet above

ground .• Trees elevations, creates a highly

reflective shield that protects them from the higher levels of intense sunlight.

• This almost shield filters out 80% of the light, preventing light from penetrating the forest.

• Consists of a thick layering branch system of limbs and vines that create natural vistas and form a natural umbrella.

• Absorbs ultra-violet rays from the sun protecting the plant and animals species beneath the canopy layer from UV rays.

• Retains moisture and makes a natural shield to prevent “wash-outs” during the flooding caused by heavy rain from the tropical rainy seasons.

• Many Epiphytic Plants, commonly called “air plants” like Bromeliads and Orchids grow in the canopy Layer.

• Roots of these plant do not reach the ground or live in soil.

• Instead they thrive by absorbing moisture and nutrients through an aerial root system by attaching themselves to a host.

• A home to many species, including birds, butterflies, monkeys, parrots, the slow moving sloth, tree frogs, toucans, jaguars and leopards.

UNDERSTORY LAYER• Directly underneath

the canopy layer and on top of the forest floor.

• Growth here is very dense.

• This layer is a dark, sometimes almost impenetrable natural habitat like vines, shrub and broadleaf trees.

CHARACTERISTICS• Provides superior camouflage and many

of the species who live here crossover between this layer and the canopy layer.

• Average 12’-15’ feet in height and have exceptionally large leaves to compensate for the lack of sunlight.

• The leaves are so large in fact, just one single leaf could be used for an umbrella.

• Many species living in this layer like darkness.

(nocturnal)

• Several animal species such as tree frogs, bats, owls, and an amazing array of insect species like the famous team working “Leaf Cutter Ants” can be found.

• Intermingling between layers is done by many species but especially by the many varieties of Monkeys, Sloths, Jaguars and Leopards. 

FOREST FLOOR• The Forest Floor is

the ground layer. • No sunlight

reaches the Forest Floor cause it is very dark.

• Quality of the soil is extremely poor and very few plants are found growing in this area.

• Examples of the plants: moss, ferns and some low growth plants and vine roots.

• It is rich in microorganism and this environment makes quick work of decomposition making a natural compost that is exceeding rich. 

• Beetles, Frogs, Lizards, Snakes, Termites, and insects of every kind thrive by the millions in the moist, dark climate of the Forest Floor.

LIGHT PENETRATION

INTRODUCTION• The light penetration level varies by

each layer.• Maintains under storey vegetation

and determines the degree of suppression or vigour of its growth.

• Each canopy layer consist of different types of plants and have their own specific characteristic and structure that can help in the light competition.

• All plants must compete to get sunlight for photosynthesis.

PHYSIOGRAPHIC LOCATION TO LEAF POSITION

• Light incident on a leaf varies with leaf angle and canopy position

• Plants can change the amount of energy they absorb by changing their effective “physiographic location”

• Heliotropic leaf movements: Some plants follow the sun by moving leaves to maximize absorption (diaheliotropism) or minimize by moving parallel to the sun (paraheliotropism)

CANOPY COMPOSITION AND DISTRIBUTION

• This affects both light quantity and light quality

• Light quantity diminishes through the canopy but all canopies are not equal.

• Incident light (PAR) at the forest floor may be different between types of forest in this world.

WHY WOULD THE PAR IS DIFFERENT BETWEEN THE

FOREST??1. Species – leaf optical properties2. Density – how much is there, LAI, LAD,

etc*Leaf Angle Distribution  refers to the angular orientation of the leaves in the vegetation *Leaf area index refers to leaf area per unit ground area

3. Architecture – Canopy structure, shape, orientation and heliotropic leaf movements give each plant its own characteristic light absorption characteristics

PHOTOSYNTHETICALLY ACTIVE RADIATION (PAR)• PAR is the amount of light available

for photosynthesis, which is light in the 400 nm to 700 nm wavelength range.

• Light is a waveform which can be measured in terms of wavelength.

• The range of human vision(400 to 700 nm) in term of wavelength is called the visible spectrum.

Reference• James M. Vose, Neal H. Sullivan, Barton

D. Clinton, and Paul V. Bolstad, (1995), Leave area index LAI, Vertical leaf area distribution, light transmittance, 1037.

• M. D. Lowman, (1986), Light interception and its relation to structural differences in three Australian rainforest canopy, Australian Journal of Ecology, 163-170

• William G. Hopkins, Norman P. A. Hunter, (2009), Introduction to Plant Physiology. The University of Western Ontario; John Wiley & Sons, Inc.

• Linda E. Graham, James M. Graham, Lee W. Wilcox (2003), Plant Biology. Upper Saddle River, New Jersey; Pearson Education.

• Murray W.Nabors,(2004), Introduction For Botany, Pearson Benjamin Cummings, United State of America, page 518.

• What Is Canopy, http://kids.mongabay.com/elementary/004.html.

• www.tigerhomes.org/animal/layers-rainforest.cfm

• Rainforest.mongabay.com/10403.htm library.thinkquest.org/27257/st3.html