Simply stated, the primary reason for tropical species 

 richness is that there is such a variety of different 

 tropical vegetation types. 



A great many species of the tropics are what we 

 call specialists: plants and animals found in only a spe- 

 cific habitat, or associated with specific hosts. For 

 plants that cannot move (once they germinate and be- 

 gin to grow) specialization is more the rule than the 

 exception. Many plant species are found only in par- 

 ticular kinds of forests, or at particular altitudinal 

 levels. Many insects and smaller animals are similar in 

 being limited to specific forest types. The larger mam- 

 mals are quite different. You can expect to find Baird's 

 tapir on Costa Rica's highest mountain as well as in 

 lowland rain forest or deciduous forest. Likewise, in 

 East Africa the elephant, the cape buffalo, the leopard, 

 and many other larger animals can be found in the 



highest montane forests as well as in savannas of the 

 hot lowlands. Very few species of plants and small 

 animals are so versatile. 



In addition to habitat specialists, tropical biotas 

 have many species of limited geographical distribution. 

 A cloud forest on the top of one volcano in Central 

 America will often have a number of species not found 

 on any other volcano, even when the forests and cli- 

 mate appear to be identical. These local species not 

 found anywhere else are call endemics. Because tropical 

 forests have so many species of limited distribution, 

 destruction of any larger forest area is likely to cause the 

 complete extinction of some species. If we lost all our 

 forest species in Illinois, not a single species would go 

 extinct; because all of these species grow in other areas 

 of the Midwest. If little Costa Rica lost all its forests 

 there would be a very different result: between 1,000 



Frequent clouds and misting l<eep the montane cloud forest cool and damp. Reserva Forestal de San Ramon, Costa Rica. 



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