TY - JOUR

T1 - Effects of nurse trees, spacing, and tree species on biomass production in mixed forest plantations

AU - Nord-Larsen, Thomas

AU - Meilby, Henrik

PY - 2016

Y1 - 2016

N2 - Growing concern about increasing concentrations of greenhouse gases in the atmosphere, and resulting global climate change, has spurred a growing demand for renewable energy. In this study, we hypothesized that a nurse tree crop may provide additional early yields of biomass for fuel, while in the longterm leading to deciduous stands that are believed to better meet the demands for other ecosystem services. Ten different species combinations were planted, with two different stocking densities, at three different sites in Denmark. Significant differences, with regard to biomass production, were observed among the different sites (P < .001) and species combinations (P < .001) after 12–13 growing seasons. Compared to pure beech stands, mixtures with beech and Japanese larch on average produced 4.4 t ha−1 yr−1 more biomass. The additional biomass production was similar to what was obtained in stands with conifers only (Sitka spruce, Douglas-fir and Japanese larch), which produced 4.9–6.1 t ha−1yr−1 more biomass than the pure beech stands. No effects of initial planting density (P = .19), or of initial weeding (P = .81), on biomass production were observed. Biomass production of the broadleaved crop was in most cases reduced due to competition. However, provided timely thinning of nurse trees, the qualitative development of the trees will allow for long-term timber production.

AB - Growing concern about increasing concentrations of greenhouse gases in the atmosphere, and resulting global climate change, has spurred a growing demand for renewable energy. In this study, we hypothesized that a nurse tree crop may provide additional early yields of biomass for fuel, while in the longterm leading to deciduous stands that are believed to better meet the demands for other ecosystem services. Ten different species combinations were planted, with two different stocking densities, at three different sites in Denmark. Significant differences, with regard to biomass production, were observed among the different sites (P < .001) and species combinations (P < .001) after 12–13 growing seasons. Compared to pure beech stands, mixtures with beech and Japanese larch on average produced 4.4 t ha−1 yr−1 more biomass. The additional biomass production was similar to what was obtained in stands with conifers only (Sitka spruce, Douglas-fir and Japanese larch), which produced 4.9–6.1 t ha−1yr−1 more biomass than the pure beech stands. No effects of initial planting density (P = .19), or of initial weeding (P = .81), on biomass production were observed. Biomass production of the broadleaved crop was in most cases reduced due to competition. However, provided timely thinning of nurse trees, the qualitative development of the trees will allow for long-term timber production.

KW - Biomass production

KW - broadleaves

KW - conifer

KW - energy

KW - growth

U2 - 10.1080/02827581.2015.1131845

DO - 10.1080/02827581.2015.1131845

M3 - Journal article

AN - SCOPUS:84955133935

VL - 31

SP - 592

EP - 601

JO - Scandinavian Journal of Forest Research

JF - Scandinavian Journal of Forest Research

SN - 0282-7581

IS - 6

ER -