Removing color from a photograph can add a lot to it; it can reveal details that would otherwise go unnoticed. Color, in some cases, may obscure the texture and form of the subjects, while black and white emphasizes the structure of the composition.
There are many ways in which the different colors turn into different grays, meaning that you can experience great light and dark richness when using black and white nature photography. While color may emphasize the shape of a subject, its black and white version may add a lot of character and feeling by highlighting its texture.
In black and white photography, the absence of light is as important as its presence. The profound shadows add depth and strength to an image. Photographers know how different colors, and lighting, react, and they use this knowledge to create impacting black and whites that deeply arouse, shock, inspire or relax.
~Byron Jorjorian from his article When Black and White Nature Photography Lights Up a Space