Forest Ecosystem and Function

Types of forests

•Tropical rain forests - Hot and humid region.

- Annual rain fall- 2000 to 4500mm. -Found in south and central America,

westren and central Africa, South east Asia, and some Islands of Indian and Pacific Oceans

-Tropical forests are considered

important because it helps in recycling water

Temperate Forests

• Cold in winter and warm and humid in summer

• Annual rain fall is 750 – 2000 mm. • Sol is rich.

• Found in Western and Central

Europe, eastern Asia and eastern North America.

Coniferous forests

• Many coniferous trees are found in this region like

spruce, fir, pine etc.

• Found in northern parts of northern America,

Europe & Asia.

• The soil in these forests is acidic and humus rich

Sub-Tropical Pine Forests,

Margalla Hil

Grasslands

• Grasslands are regions where average

precipitation is high (250 – 1500 mm) for grass and for trees to grow.

• Rain fall are erratic and uncertain in these region • Regions found in central & south America,

subequitorial Africa & South Australia, south India

Thar Desert

Thar is the Largest Desert Of

Pakistan. It is situated in the

province of Sindh. This desert also enters the boundry of India therefore it is one of the largest deserts of Asia. Thar desert in Pakistan spreads over an extensive area in Ghotki, Sukkar, Sanghar, Mirpur Khas and Tharparkar districts. The desert consist of barren tracts of sand dunes covered with thorny bushes, mostly acacia. The desert is separated from irrigated area by the bed of the Eastern Nara. The Cholistan Desert adjoins the Thar desert spreading into Pakistani Punjab province. Thar desert of Pakistan and India is the 9th largest desert of the world. The total length of Thar desert in Sindh (Pakistan) and Rajhistan (India) is 200,00

DESERT

A desert is a land scape

form or

region

that

receives

very

little

precipitation.>250mm per annum.

MOUNTAIN

Mountain is land form that extends

above the surrounding terrain in

CHARACTRISTICS

• Mountain cover the 20% of land area. • Going up the mountain is similar to

moving from equator to north pole. • Mountain are the reseviors of water. • A big bank of Biodiversity.

The following forest types of

Pakistan are found in Pakistan.

•Littoral and swamp forests •Tropical dry deciduous forests •Tropical thorn forests

•Sub-tropical broad -leaved evergreen forests. •Sub- tropical pine forests

• Himalayan moist temperate forests •Himalayan dry temperate forests •Sub alpine forests

Distribution of Pakistan`s forests

Natural forsets and manmade tree plantations cover 4.224 million ha, or 4.8% of of the land area in the country.Anonymous 1992, Amjad et al 1996. Agriculture , both irregated and non- irrigated, is practiced on 20.58 million ha, or 23.4 % of the land area, and live stock grazing on 28.509 million ha, oe 32.4 %, consists of snow, glaciers, rock, deserts tidal flats, water bodies river beds, lakes, dames, towns cities and so forth. The non-productive use of most of the land area is due to he arid climate.

Forest ecology effects,

All sources categories

•Forest health • T & E species,

•Timber and wood products •Cultural resources

•Soils • Esthetics & reaction

•Water

•Aggroforestry & spl. Forest Prod • Fish & wild life

Ecosystem consists of …

Communities of animals(living) things: Plants, animals, microbes, et al.

Inanimate stuff (rocks, soils, grasses, chemicals).

Exchange matter and energy: within the system

Between systems

Ecosystem structure

(size and arrangement of planta and animals, dead stuff ft al)

OPERATIONAL Env.

Ecosystem function

(The operational environment exchange of matter and energy)

Operational Environment

the physical environment around a living oragnism;governs how ecosystem interact

Light Mechanical

Plant

Oprerational environment effects

every thing.

•Growth

•Disease

•Insect

•Reforestation

•Distribution of plants

Oprerational environment effects

every thing.

•Big drivers Not so big drivers -Climate – timber harvest -Elevation slope aspect -Silviculture

-Geology and soils - Land conversion

-Land conversion -Microclimate -Fire policy - Land slides

-Floods - Floods

Which leads to…

Why are plant species found where they

are found?

Answer: Its evolved adaptation to its

surrounding operational

And

….

Ecological communities

• Plants and animals are occurring together in a coherent group because of their aptations to each other and the surroundings

Environment

• (Communities become ecosystems when we include processes behind interaction and interdependency)

•Temperature and water availability

are two big drivers in determinig forest type:

Fire is important …

Geology, e.g. serpentine soils, may be locally

important

Natural forces (disturbances) modifying

the operational environment….

•wind throw

•Earth quake

•Root disease

• Land slides

• Global climate change

• floods

Fire natural and human caused , is a mjor

force drive plant succession in forests..

Some trees and shrubs are adapted for

fire, while others are not.

Forest succession

Community changes, because plants

change the operational environment

Forest succession

Primary succession Secondary succession

Following big distribution After initial plant Early seral plant species Late seral species

Best in full sun light conditions Best tolerant shade and other understory conditions

Forest succession

• The changed

operational

environment

may help

perpetuate the

existing plant

community, OR

Set the stage

for the next

community.

Succession in an even aged Fir

forests

Succession may have many end points • 45 year old Fir stand • Root disease s and bark beetles affecte d out come

What about human induced

ecosystem change?

Harvesting affects operational environment here…greatly increased light, heat, water, chemical turn over; Sol

Thinning effects: Less increase in light, heat, water, nutrient turn over;

Mechanical damage to leaves tree? Soil compaction?

Productivity…what makes the

whole work done

Oceanic production by the process of Photosynthes

Terrestrial

production

Trophic levels - plural-Noun

Each of several hierarchical levels in

an ecosystem, consisting of

organisms sharing the same function

in the food chain and the same...

The trophic level of an organism is the position it occupies in a food chain. The word trophic derives from the Greek τροφή (trophē) referring to food or feeding. A food chain represents a succession of

organisms that eat other…

First trophic level. The plants in this image, and the algae

and

phytoplankton in the lake, are

primary

producers. They take nutrients from the soil or the water, and manufacture

their own food by

photosynthesis, using energy from the sun.

Trophic levels

Energy flows are like log processing: there`s an attempt to maintain maximum value at every step,

orecologically, nature tends to fill all niches with communities.

Overview

basic ways organisms get food are as producers,

consumers and

decomposers .

The T1 level

The environmental drivers determining productivity species location also determine productivity. Soils management is very important.

Nice little T2

herbivores at work…

Spruce bud worm may be a serious pest on over stocked with firs.

Second trophic level

Rabbits eat plants at the first

trophic level, so they are primary

Fourth trophic level

Golden eagles eat foxes at the third trophic level, so they are

Decomposers T5 are

Decomposers includes larger insects, and a fanastic variety of microscopicinsects, bacteria, fungi and actinomycetes.

The fungi on this tree feed on dead matter, converting it back to nutrients that primary

Mycorrhizae

•Mutual benefits

-Greatly expanded root net-work (increased).

- Esential hormones

- Pathogens

protection-- Attracts microscopics insects for bu poop near roots

-- fungal get food from tree - White is mycorrhiza

What happen within and around a primary root…?

Ecosystem resilience & suatainability

Our forest

ecosystems

are adapted

to various

types of

natural

disturbance

s.s

Undersatnding Resiliencey: Diturbance

does not exceed system ability to

recover:

•Self healing

•Redundancy

•Genetic diversity within and between

species

Redundancy is a form of dismissal

Redundancy is a form of dismissal. A genuine redundancy only arises in three very narrowly

defined circumstances: the closure of the business,:

the closure of a particular workplace – for example an academic unit, department,

course, unit or office/building:

a reduction in the need for employees – the test being not whether an employer needs fewer employees, but whether it needs fewer employees to do work of a particular kind. This

Sustainability

•Sustainability is meeting present

needs without compromising the

future.

•Not pushing an ecosystem beyon its

ability to recover

Practices that drastically alter the operational environment, such as terracing for site preparation,can be successful,

though not politically acceptable.

Legacies

As long as enough undisturbed ecosystem pieces remain, the system will recover

Sustainability is like good equipment

operation & maintenance….

The right machinery and a knowledgeable operator are very important……. As is leaving enough of the right pieces intact.

Within stands and across landscapes,

sustainability takes human in genuity working

with Mother nature.