Factors influencing the growth of radiata pine plantations in Chile

We examined environmental factors affecting growth rates of Pinus radiata in Chile. The relationships between annual volume growth and soil, climate, canopy and stand factors were analysed using data from 48 permanent sample plots in P. radiata plantations in central Chile. Water availability (as affected by precipitation, soil water holding capacity and potential evapotranspiration) appeared to be the factor most limiting to leaf area and growth. Maximum growing season temperature also negatively affected growth. Sites with the highest productivities had the lowest annual water deficits. The most productive sites used water and light more efficiently. Growth per unit of potential evapotranspiration ranged from 0.5 to 1.6 kg of wood per m3 of water and growth per unit of radiation ranged from 0.3 to 0.5 g of wood per MJ of photosynthetically active radiation for low and high productivity sites. The inclusion of simple climatic variables such as maximum temperature and precipitation into Chilean P. radiata growth and yield models should improve their performance.