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.

森林动态特征、森林管理规划和产量表均基于树龄-生产力关系（立地质量指数）。然而，之前的研究表明，黑云杉（Picea mariana）的树龄是通过地面环数（通常）获得的。称为“根颈”）并不能给出树木的真实年龄，因为成熟时，黑云杉树的根系完全是不定根，这意味着不定根沿着茎基部发育。最初的根不会随着时间的推移而发育和消失，通过将生长环和根颈隐藏在树桩木材和根部下方，根部沿着茎的发育在一定程度上“隐藏”了树木的真实年龄。生产力的估计主要取决于树木的年龄，当年龄错误时，这些估计也是错误的，并可能导致管理者做出错误的决定，例如，林分可能比地面环数显示的年龄要老得多。 ，这会自动导致生产率高估，错误的管理决策。 该研究项目的主要目标是估计黑云杉在不同条件下生长的老化错误，利用这些估计来量化生产力高估，并通过定位发芽日期（真实年龄）开发产量表和地点指数的校正工具。隐藏在黑云杉树桩内，我们将计算精确的年龄低估和相关的生产力高估。从根本上讲，我们希望确定有利于不定根发育的条件，从而确定增加年龄的场地条件。在应用层面上，对与老化错误相关的生产力高估进行量化将为管理者提供更好的数据作为其规划决策的基础。