Aging mistakes and overestimation of productivity for black spruce forests

森林动态、森林管理规划和产量表的特点都是以年龄-生产力关系（立地质量指数）为基础。然而，以前的研究表明，通过地面年轮计数（通常称为"根颈“）获得的黑云杉（Picea mariana）的年龄并不能给出树木的真实的年龄，因为不定根沿着茎的基部发育。在成熟期，黑云杉树的根系完全是不定的，这意味着最初的根不会随着时间的推移而发展和消失。根沿着茎的发育在一定程度上“隐藏”了树木的真实年龄，通过将年轮和根颈隐藏在树桩和根下。由于森林动态的特点和生产力的估计主要取决于树木的年龄，如果年龄错误，这些估计也是错误的，可能导致管理人员作出错误的决定。例如，一个林分的年龄可能比从地面年轮计数中看出来的要大得多，这会自动导致生产力高估和错误的管理决策。

Characterization of forest dynamics, forest management planning and yield tables are all based on age-productivity relationships (site quality indices). However, it was previously shown that age of black spruce (Picea mariana) obtained by a ring count at ground level (commonly referred to as «the root collar») does not give the real age of trees, because of the development of adventitious roots along the base of the stem. At maturity, the root system of black spruce trees is exclusively adventitious, which means that the initial roots do not develop and disappear with time. The development of roots along the stem somewhat «hides» the true age of trees, by concealing growth rings and the root collar into the stump wood and under the roots. Since the characterization of forest dynamics and estimations of productivity mainly lie on the age of trees, when ages are wrong, those estimates are also wrong and can lead to bad decisions by managers. For example, a forest stand could be much older than it appears from a ring count at ground level, which automatically leads to productivity overestimations and erroneous management decisions.