Aging mistakes and overestimation of productivity for black spruce forests

黑云杉林的老化错误和生产力高估

• 批准号: 445212-2012
• 负责人: DesRochers, Annie
• 金额: $ 1.95万
• 依托单位: Université du Québec en Abitibi-Témiscamingue
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=575029
• 关键词: Aging; mistakes; overestimation; productivity; black

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. The main goal of this research project is to estimate aging mistakes of black spruce growing in different conditions, to use these estimates to quantify productivity overestimations and to develop a correction tool for yield tables and site indices. By locating the germination date (true age) concealed inside black spruce stumps, we will calculate precise age underestimations and associated productivity overestimations. On a fundamental level, we expect to determine conditions favourable to the development of adventitious roots, and hence site conditions that increase age underestimations. On an applied level, the quantification of productivity overestimations associated to aging errors will give managers better data on which to base their planning decisions.

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。 本研究项目的主要目标是估计在不同条件下生长的黑云杉的老化错误，使用这些估计来量化生产力高估，并开发一个校正工具，产量表和网站指数。通过定位隐藏在黑云杉树桩中的发芽日期（真实年龄），我们将计算出精确的年龄低估和相关的生产力高估。在一个基本的水平上，我们希望确定条件有利于不定根的发展，因此现场条件，增加年龄低估。在应用层面上，量化与老化错误相关的生产力高估将为管理人员提供更好的数据，以作为其规划决策的基础。