Thinning forests can affect how much they grow, depending on the site conditions. Some forests may grow more in basal area rather than height, even if they look the same. Thinning can reduce growth, especially with heavy thinning, but light thinning can help in some places. The relationship between height growth and volume growth varies by site, so it's important to have unthinned plots for accurate predictions. Different sites respond differently to thinning, with water supply and root depth playing a big role. It's important to consider these factors when managing forests for growth and yield.