摘要
Tree shelters are used in many forestry applications because they often improve survival, may stimulate early growth, and can help to maintain apical dominance. Quercus robur, widely used in multipurpose plantings in Europe, usually grows slowly and loses apical dominance in the early stages after establishment. We examined tree shelter effects on Q. robur seedling field establishment in Italy, focusing on the influence on shoot system structure (branching, apical dominance), root system development, and shoot versus root system balance. Three field treatments were evaluated: control and two diameter shelters. After 2?years, plants were measured by destructive analysis. Shelters increased height, as a result of multiple flushes during the growing season, which became more pronounced from the first to the second field season. Sheltered seedlings had fewer, shorter branches and maintained apical dominance. Both shoot and root system biomass allocation in sheltered plants was reduced relative to unprotected plants, and biomass was allocated mostly to the shoot system. In contrast, plants without shelters invested more resources toward a larger, wider root system. We conclude that shelters modify the above- and below-ground structure and balance of regenerating oak seedlings in the early field stages, promoting development of productive plantations that may require reduced cultural intensity. However, above-ground growth was not equally balanced by below-ground development, which may lead to disadvantages especially under harsh site conditions.