Growth and Biomass Models for Three Fast-growing Tree Species under High-density Plantation

Three fast-growing trees, viz., Populus deltoides, Eucalyptus spp. and Casuarina equisetifolia were studied, in high-density plantation at Padilla, Prayagraj, Uttar Pradesh with following treatments viz., T1: Poplar (1×1m), T2: Eucalyptus (1×1m), T3: Casuarina (1×1m), T4: Poplar (1.2×1.2 m), T5: Eucalyptus (1.2×1.2 m), T6: Casuarina (1.2×1.2 m), T7: Poplar (1.5×1.5 m), T8: Eucalyptus (1.5×1.5 m) and T9: Casuarina (1.5×1.5 m). The experiment was established in year July 2021 and data was collected in June 2022. The result indicate the maximum height was recorded in T2: Eucalyptus (1×1 m) 3.81 m followed by T5: Eucalyptus (1.2×1.2 m) 3.78 m, T8: Eucalyptus (1.5×1.5 m) 3.40 m which was at par with each other and minimum in T9: Casuarina (1.5×1.5 m) 2.42 m whereas the maximum girth was found in T4: Poplar (1.2×1.2 m) 6.91 cm followed by T2: Eucalyptus (1×1 m) 6.61 cm, T5: Eucalyptus (1.2×1.2 m) 6.16 cm, T1: Poplar (1×1 m) 5.91 cm which was at par with each other and minimum in T9: Casuarina (1.5×1.5 m) 3.22 cm after one year. Various linear function was attempted to predict biomass based on GBH (G) and Height (H). Prediction accuracy of Height, girth model was slightly better than the height and girth model. Linear model (Y=a + bH + cG), where Y denotes dependent variable (biomass) and H and G denotes independent variable (Height or Girth), performed better (than the remaining tested models) in terms of estimation precision and prediction accuracy. The AGB was maximum was found in T2: Eucalyptus (1×1m) 0.676 kg tree-1 followed by T5: Eucalyptus (1.2×1.2 m) 0.598 kg tree-1 and minimum in T9: Casuarina (1.5×1.5 m) 0.214 kg tree-1. After completion of one year Eucalyptus (1×1 m) showed best growth among all treatments.