(N/A) Biodiversity is not uniform throughout the world; it varies with changes in latitude and altitude.
- For many groups of animals and plants,there are specific conditions that determine their distribution.
- Plants and animals are more diverse in areas that are best suited for their survival.
Latitudinal gradients:
The diversity of plants and animals is not uniform throughout the world but shows an uneven distribution.
For many groups of animals or plants,there are interesting patterns in diversity,the most well-known being the latitudinal gradient in diversity.
- In general,species diversity decreases as we move away from the equator towards the poles.
- With very few exceptions,the tropics (latitudinal range of $23.5^{\circ} N$ to $23.5^{\circ} S$) harbour more species than temperate or polar areas.
- Colombia,located near the equator,has nearly $1,400$ species of birds,while New York at $41^{\circ} N$ has $105$ species and Greenland at $71^{\circ} N$ has only $56$ species.
- India,with much of its land area in the tropical latitudes,has more than $1,200$ species of birds.
- $A$ forest in a tropical region like Ecuador has up to $10$ times as many species of vascular plants as a forest of equal area in a temperate region like the Midwest of the $USA$.
- The largely tropical Amazonian rain forest in South America has the greatest biodiversity on Earth. It is home to more than $40,000$ species of plants,$3,000$ of fishes,$1,300$ of birds,$427$ of mammals,$427$ of amphibians,$378$ of reptiles,and more than $1,25,000$ invertebrates.
- Scientists estimate that in these rain forests,there might be at least two million insect species waiting to be discovered and named.