The incorporation of a constraint on minimum bird density (MVP
ha−1 = 50) led to an increase in optimal rotation length of 2.9 years
(or 36%) on average, an increase in bird density from a minimum of 41
to a maximum of 54 individuals ha−1 year−1 (approximately by 32%),
and a decrease in the NPV froma maximumof 15.93 million VND ha−1
(937.06 USD ha−1) to a minimum of 9.68 million VND ha−1
(569.41 USD ha−1) (by 39%). Lengthening the rotation age by 36%,
would benefit biodiversity conservation with 28% higher in bird density,
and an increased supply of large-sized timber, both for a relatively small
decrease in the NPV of 12%.