Biology in the San Juans

A mantle of green vegetation covers the San Juan Mountains and softens the appearance of the rugged slopes and valleys. The plant life also provides homes for myriad creatures, large and small. The study of ecology centers on patterns in distribution of plant and animal species and the reasons for these patterns.

In general, each species is found only in environments where the limiting factors are conducive to its survival. These limiting factors may be physical (for example, low temperatures or lack of water) or biological (for example, the presence of a competitor or predator). Most species do not occupy all the habitats that potentially could support them because they have never had the opportunity to spread into all suitable areas. In addition to understanding the distribution of individual species, the ecologist is concerned with assemblages of species, or biotic communities, and with the physical and biological factors controlling the distribution of these communities across the landscape.