TY - JOUR
T1 - Passive versus active afforestation of agricultural land
T2 - Two decades of impacts on tree biomass and ecosystem carbon storage
AU - Timilsina, Sachin
AU - Byriel, David Bille
AU - Boursicaud, Nathan Le
AU - Barsotti, Davide
AU - Rosas, Yamina Micaela
AU - Zimmermann, Anna Karina
AU - Riis-Nielsen, Torben
AU - Schmidt, Inger Kappel
AU - Vesterdal, Lars
AU - Gundersen, Per
AU - Manlay, Raphaël J.
AU - Kepfer-Rojas, Sebastian
N1 - Corrigendum: 10.1016/j.foreco.2026.124019
PY - 2026
Y1 - 2026
N2 - Biodiversity loss and climate change are major 21st century challenges, driven by land-use change and agricultural intensification. Passive restoration through natural colonization offers a cost-effective way to recover biodiversity and carbon stocks, but its carbon sequestration potential in agricultural landscapes remains unclear. We quantified tree species composition, biomass, soil organic carbon (SOC), and ecosystem carbon stocks across four land-use types—agricultural land (year 0), naturally colonized abandoned land (21 ± 2 years), plantation forests established on former cropland (21 ± 2 years), and mature, long-term forests under active management (132 ± 11 years) in ten Danish landscapes. Biomass was estimated in 120 plots (three 400 m² plots per land-use), while SOC and ecosystem carbon stocks were quantified in 84 plots (excluding mature forests). Naturally colonized forest differed in tree species composition from mature and afforested plantations. Mature forests had the highest total wood biomass (311 ± 47 Mg ha−1), followed by plantations (117 ± 9 Mg ha−1) and naturally colonized areas (7.5 ± 2.3 Mg ha−1). Plantations stored more ecosystem carbon (117 ± 7 Mg ha−1) than naturally colonized (56 ± 3 Mg ha−1) or agricultural land (58 ± 7 Mg ha−1). The slightly lower carbon stocks in naturally colonized sites likely reflect early post-abandonment SOC dynamics (∼22 years), where redistribution and initial losses of plough-layer carbon precede long-term soil carbon accumulation. While topsoil SOC (0–10 cm) did not differ among land-uses, deeper soil (10–25 cm) showed higher SOC in agricultural land compared to naturally colonized and plantation forests. Our results show that, after two decades, natural colonization promotes distinct and more diverse tree species communities, whereas plantations maximize carbon storage, highlighting the need to balance biodiversity and carbon objectives in reforestation strategies.
AB - Biodiversity loss and climate change are major 21st century challenges, driven by land-use change and agricultural intensification. Passive restoration through natural colonization offers a cost-effective way to recover biodiversity and carbon stocks, but its carbon sequestration potential in agricultural landscapes remains unclear. We quantified tree species composition, biomass, soil organic carbon (SOC), and ecosystem carbon stocks across four land-use types—agricultural land (year 0), naturally colonized abandoned land (21 ± 2 years), plantation forests established on former cropland (21 ± 2 years), and mature, long-term forests under active management (132 ± 11 years) in ten Danish landscapes. Biomass was estimated in 120 plots (three 400 m² plots per land-use), while SOC and ecosystem carbon stocks were quantified in 84 plots (excluding mature forests). Naturally colonized forest differed in tree species composition from mature and afforested plantations. Mature forests had the highest total wood biomass (311 ± 47 Mg ha−1), followed by plantations (117 ± 9 Mg ha−1) and naturally colonized areas (7.5 ± 2.3 Mg ha−1). Plantations stored more ecosystem carbon (117 ± 7 Mg ha−1) than naturally colonized (56 ± 3 Mg ha−1) or agricultural land (58 ± 7 Mg ha−1). The slightly lower carbon stocks in naturally colonized sites likely reflect early post-abandonment SOC dynamics (∼22 years), where redistribution and initial losses of plough-layer carbon precede long-term soil carbon accumulation. While topsoil SOC (0–10 cm) did not differ among land-uses, deeper soil (10–25 cm) showed higher SOC in agricultural land compared to naturally colonized and plantation forests. Our results show that, after two decades, natural colonization promotes distinct and more diverse tree species communities, whereas plantations maximize carbon storage, highlighting the need to balance biodiversity and carbon objectives in reforestation strategies.
U2 - 10.1016/j.foreco.2026.123936
DO - 10.1016/j.foreco.2026.123936
M3 - Journal article
SN - 0378-1127
VL - 617
JO - Forest Ecology and Management
JF - Forest Ecology and Management
M1 - 123936
ER -