The plants, restricted to a definite are only for their distribution are called endemics and this phenomenon is called endemism. The definite area may be continent, country or province, and small area.
Image Source: ggarrardresearch.files.wordpress.com/2012/03/word-cloud-1503122.jpg
The endemics have two characteristics:
May be of recent origin and have not the opportunity to occupy a large area through migration e.g. Vernonia.
ADVERTISEMENTS:
Survivors of ancestor with mid range of distribute e.g. Gink biloba.
A species that is found in only a single geographical area and how where else is called endemic to that area. When environments are damaged by human activity, the population sizes of many species that not all species will go extinct the greatest destruction of biological communities has occurred during the last 150 years during which human populations went from 1 billion to 7 billion. The habitat destruction, fragmentation, degradation, disease, over exploitation causes problems to species survivals. Ecologists have observed such species for conservation of biodiversity.
These categories are:
1. Species with a narrow geographical range.
ADVERTISEMENTS:
2. Species with only one or a few populations.
3. Species in which population size is small.
4. Species with low population density.
5. Species requires a large home range.
ADVERTISEMENTS:
6. Species that have large body size.
7. Species with low rates of population increase.
8. Species that are not effective dispersers.
9. Species that migrate.
10. Species with specialized niche requirements and genetic variability.
11. Species characterized to stable environment.
12. Species with aggregation or harvested by people.
To highlight the legal states of rare species for purpose of conservation the IUCN (1988) have established main conservation strategies.
1. Extinct:
The last remaining number of the species had died or is presumed to have died beyond reasonable doubt. In certain case captive individuals survive, but there is no free living natural population.
2. Critical:
Critically endangered, faces an extremely high risk of extinctions in the immediate future.
3. Endangered:
Faces a very high risk of extinction in the near future.
4. Vulnerable:
Species that may become endangered in the near future because populations of the species are decreasing in size throughout its ranges.
5. Rare:
Species that have small total numbers of individuals after due to limited geographical ranges or low population densities.
6. Secure or lower risk:
No immediate threat to the survival of the species.
Mace & Landle (1991) have proposed a three level system of classification based on the probability of extinction.
1. Critical species with 50% or greater probability of extinction within 5 years or 2 generation whichever is larger.
2. Endangered: Species with 20% probability of extinction within 20 years or 10 generations.
3. Vulnerable: Species with 10% probability of extinction within 100 years.
Endangered Mammals
1. Blue Whale 2. Chimpanzee, 3. Giant Panda, 4. Fin Whale 5. Gorilla, 6. Tiger
Endangered birds
Kiwi (Apteryx anstralis)
Indian White Rumped Vulture {Gyps bengalensis)
Endangered reptile
Ripley’s Turtle
Endangered amphibians
Desert slender Salamander (Batrachoseps aridus) Palmate newt (Triturus helvenetica).
Endangered plants:
6% of identified plant species are endangered. E.g. Pinus squamata in China, Clianthus puniceus (Lobster clow), Madonna lily (Lilium candidum).