Trade-offs and Synergies Between Economic Gains and Plant Diversity Across a Range of Management Alternatives in Boreal Forests

Intensive forest management activities that maximize economic gains could have a negative impact on the ecosystems and generate environmental conflicts, which may in turn translate to poor delivery of ecosystems services. Although plant diversity is positively associated with multiple ecosystem functions, it remains unclear how economic gains influence plant diversity across vegetation strata. We analyzed the relationships between economic gains, assessed as profit, and plant species richness following forest management alternatives (managing rotation age and overstorey composition) for the boreal forests of Canada. We found a hump-shaped relationship between total plant richness and profit, with total plant richness increasing initially, reaching a peak, and then declining with increasing profits. The relationship between profit and plant diversity differed among vegetation strata. Understorey plant richness followed similar trends to total plant richness, but overstorey tree richness increased linearly. The results of path analysis presented management alternatives as major drivers determining profit and plant diversity across vegetation strata. Our analysis indicated that maximum profit ($5000/ha) could lead to 20% loss of total plant species richness. Among the alternatives we compared, we conclude that managing for mixedwood with approximately a rotation of 100 years is an optimal compromise between economic and plant diversity objectives.