Many national parks were established for the preservation of endangered species.

preservation 是动词 preserve 的名词形式，由前缀 pre-（表示"预先"）和词根 serve（保持）组成，字面意思是"预先保持"。在环保语境中特指"保护、保存（自然资源或物种）"。 preservation of endangered species 就是指"对濒危物种的保护"。