The Role Of Disturbance In Shaping The Biogeography

Introduction

What is shaping biogeography ?

Shaping the biogeography is adjustment and distribution of species and ecosystems in geographic space and through geological time

What are the disturbances ?

Any relatively discrete event in time that disrupts or catastrophic events

Types of disturbance

Mainly these disturbances effect on

Species diversity

Land mass

Habitats

Regional and global climates

Natural

Anthropogenic

Autogenic

Disturbances

Plate tectonics

Other natural disturbances

Perturbations

According to the plate tectonics theory, the uppermost mantle, along with the overlying crust, behaves as a strong, rigid layer. This layer is known as the lithosphere.

A theory that states that the earth’s crust is made up of a number of plates which move over a liquid crust that get created and destroyed over time.

What is the plate tectonics

A plate is one of numerous rigid sections of the lithosphere that move as a unit over the material of the asthenosphere.

A Side View Of Structure Of Earth

Tectonics History

Tectonic Plates of The Earth

There are 16 tectonics plates and 7 tectonics plates are consider as main tectonics plates

Continental Plates

Main tectonics plates

• African Plate

• Antarctic Plate

• Australian Plate

• North American Plate

• South American Plate

• Eurasian Plate

• Pacific Plate - Oceanic Plate

Plate Tectonics Mechanism by video

Effect of Plate Tectonics

Effect on the area of landmasses and marine basins – Plate tectonics helps to create continents , Ocean and Islands

Effect on isolation and opportunities for Biotic exchange

• As Pangea began to separate into separate continents before130 Million years , creating physical barriers such as seas, restricting migration to within the continents

• Gene pools of species are separated and as they are exposed to different physical and biotic conditions, each portion of the species adapts differently and eventually forms new species on the separated continents

Example – Australian continent is the most rich of speciation due to isolation

Effect on regional and global Climates

• Due to Continents separate and latitudinal shifting it cause to different climates on different continents

• Due to continents drifted over or near the pole it causeto cold climate at there

Example – Arctic & Antarctic

Different climates on The Earth

Other natural disturbances

Geographical Factors – Mountains , Rivers , Oceans

These geographical factors help for separating a species to two or more groups and to Isolation of each groups

Perturbations

Perturbations such as floods , volcanoes & wildfires are cause to remove or termination of species from a certain places and it cause to find new shelters and spreading to new places

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