New study offers evidence against the conventional wisdom on tree species richness and stand biomass regulation. Our results indicated that high-density monocultures would not only have the potential to yield greater stand biomass in Pinus sylvestris plantations compared with common practices from tropical and subtropical zones, but strategies totally opposite of these, at least for this boreal species
The Boreal Biomass Boost
Published in Forest Ecosystems, the study took data gathered at 1,076 Pinus sylvestris planted sample plots across China’s boreal zone. The study showed that high-density monocultures containing 2,000-2,500 trees per hectare exhibit the most advantageous management strategy for enhancing stand biomass in such plantations.
This is in contrast to the potentially widely held belief that stand biomass is maximiz
a new study offers evidence against the conventional wisdom on tree species richness and stand biomass regulation. Our results indicated that high-density monocultures would not only have the potential to yield greater stand biomass in Pinus sylvestris plantations compared with common practices from tropical and subtropical zones, but strategies totally opposite of these, at least for this boreal species
ed through increasing tree species richness as has been found in tropical and subtropical forest experiments. However, the effect of tree species richness on stand biomass went from positive to negative with stand age in the boreal zone, whereas effects of stand density always stayed positive.
High-Density Monocultures:The Pros and Cons
One of the reasons for seeding extra high-density monoculture that not only stands biomass increases magnificently, but one of the main demerits factor is balanced with it. They found that this leads to lower diversity of species and smaller trees at maturity.
“Rely on our empirical analysis and experimental manipulation data, we concluded that the positive effect of tree species richness on stand biomass changed to negative as stands matured, whereas the impact of stand density was consistently positive,” said Dr. Wei Chen from Institute of Applied Ecology, Chinese Academy of Sciences, corresponding author.
The effect of tree species richness on stand biomass was in general negative, whereas the effect of stand density fluctuated between neutral and positive (Chen et al. 2012). One unexpected finding was that we failed to detect a consistent positive effect of the experimental manipulation of-tree species richness on stand biomass, which contrasts with observations from similar tropical and subtropical forest experiments (cf. Mitchell et al. 2009). This result was because the negative selection effect counteracted the positive complementary effect.
Conclusion
This study provides a unique plantation strategy that can be used to optimize stand biomass for Pinus sylvestris plantations in the boreal zone. Thus, it questions conventional wisdom about the role of tree species richness on stand biomass and suggests that local environmental constraints should be taken into account when designing plantations. There may be trade-offs with this high-density monoculture approach, but it shows promise as a method to increase biomass production in the boreal.
