Linked from
The 7 pages that link to Tea oxidation, each with the reason it gives.
Camellia sinensisRelated: Its extent is deliberately managed to shape tea color, aroma, and taste.
TeaRelated: Its degree helps distinguish green, oolong, and black tea.
Tea processingRelated: Its extent is controlled to distinguish green, oolong, and black tea styles.
OolongRelated: The degree and timing of oxidation distinguish many oolong styles.