United Nations Decade on Biodiversity-defination+

Biodiversity is the degree of variation of life forms within a given

• species, ecosystem, biome,genetic or an entire planet.
• Biodiversity is a measure of the health of ecosystems.
•  Biodiversity is in part a function of climate.
• Biodiversity is the result of 3.5 billion years of evolution.
• In terrestrial habitats, tropical regions are typically rich whereas polar regions support fewer species.
• Rapid environmental changes typically cause mass extinctions.
• The period since the emergence of humans has displayed an ongoing biodiversity reduction and an accompanying loss of genetic diversity.
• the Holocene extinction, the reduction is caused primarily by human impacts, particularly habitat destruction.
• The most recent, the Cretaceous–Tertiary extinction event, occurred 65 million years ago, and has often attracted more attention than others because it resulted in the extinction of the dinosaurs.^[
• Conversely, biodiversity impacts human health in a number of ways, both positively and negatively.
• One estimate is that less than 1% of the species that have existed on Earth are extant.
• The United Nations designated 2011-2020 as the United Nations Decade on Biodiversity.
• Measuring diversity at one level in a group of organisms may not precisely correspond to diversity at other levels  (  However, tetrapod (terrestrial vertebrates) taxonomic and ecological diversity shows a very close correlation).
• Generally terrestrial biodiversity is up to 25 times greater than ocean biodiversity.
• Diversity consistently measures higher in the tropics and in other localized regions such as Cape Floristic Province and lower in polar regions generally.

DEFINATION

"Biological diversity" or "biodiversity" can have many interpretations. It is most commonly used to replace the more clearly defined and long established terms, species diversity and species richness.

•  Biologists most often define biodiversity as the "totality of genes, species, and ecosystems of a region". An advantage of this definition is that it seems to describe most circumstances and presents a unified view of the traditional three levels at which biological variety has been identified:
• species diversity
• ecosystem diversity
• genetic diversity

 The 1992 United Nations Earth Summit defined "biological diversity" as "the variability among living organisms from all sources, including, 'inter alia', terrestrial, marine, and other aquatic ecosystems, and the ecological complexes of which they are part: this includes diversity within species, between species and of ecosystems".^[This definition is used in the United Nations Convention on Biological Diversity.
One textbook's definition is "variation of life at all levels of biological organization".^[16]
Geneticists define it as the diversity of genes and organisms. They study processes such as mutations, gene transfer, and genome dynamics that generate evolution.




WHAT ARE Hotspots ?

• A biodiversity hotspot is a region with a high level of endemic species.
•  Hotspots were first named in 1988 by Dr. Sabina Virk.
•  Many hotspots have large nearby human populations.
•  While hotspots are spread all over the world, the majority are forest areas and most are located in the tropics.
• Brazil's Atlantic Forest is considered one such hotspot, containing roughly 20,000 plant species, 1,350 vertebrates, and millions of insects, about half of which occur nowhere else.

• The island of Madagascar, particularly the unique Madagascar dry deciduous forests and lowland rainforests, possess a high ratio of endemism. Since the island separated from mainland Africa 65 million years ago, many species and ecosystems have evolved independently.
• Indonesia's 17,000 islands cover 735,355 square miles (1,904,560 km²) contain 10% of the world's flowering plants, 12% of mammals and 17% of reptiles, amphibians and birds—along with nearly 240 million people.
• Many regions of high biodiversity and/or endemism arise from specialized habitats which require unusual adaptations, for example alpine environments in high mountains, or Northern European peat bogs.

Accurately measuring differences in biodiversity can be difficult. Selection bias amongst researchers may contribute to biased empirical research for modern estimates of biodiversity.