Abstract: One-year-old silver birch (Betula pendula Roth) saplings were subjected to artificial insect damage and defoliations of varying intensities, and subsequent growth indexes, biomass allocation patterns and photosynthesis were monitored during a 60-day period. Seven treatments were conducted in which the leaves of saplings were perforated with three or six holes per each leaf, and damaged by clipping one-third of each leaf, or they received 25, 50 and 75% defoliations during a single growing season (from April to August of 2014). Simulated insect damage and artificial defoliation decreased growth. The 75% defoliation significantly reduced the total dry mass of birch saplings at harvest by 30%, while such reduction did not influence the total productivity. The dry mass of leaves was reduced by 45% when saplings were defoliated by 75% compared to not defoliated saplings. Moreover, the total production of leaves significantly increased in the 75% defoliated saplings compared with control saplings. Artificial defoliation increased the relative biomass allocation to foliage, and this was more evident in defoliated than in mechanically insect-damaged saplings. Despite losing 25, 50 or 75% of leaf mass due to clipping, defoliated birch saplings recovered similar dry masses and root/shoot ratios by harvest as the non-defoliated saplings. Perforation and clipping parts of the leaves, as well as the artificial defoliations, caused the regrowth of biomass that did not significantly change compared to healthy silver birch saplings, and this phenomenon could be assessed as equal-compensatory growth.