Readily available resources across sites and genotypes result in greater aboveground growth and reduced fine root production in Pinus taeda
Readily available resources across sites and genotypes result in greater aboveground growth and reduced fine root production in Pinus taeda
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DOI：
10.1016/j.foreco.2022.120431
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发表时间：
2022-10
影响因子：
3.7
通讯作者：
Timothy J. Shively;R. Cook;C. Maier;Kevin Garcia;T. Albaugh;O. Campoe;Z. Leggett
中科院分区：
文献类型：
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作者：
Timothy J. Shively;R. Cook;C. Maier;Kevin Garcia;T. Albaugh;O. Campoe;Z. Leggett
细根是树木和土壤之间的主要界面，它们对环境条件的反应是动态的。在许多功能中，它们是收集养分和水分的主要功能，它们构成了树木的主要组成部分。它们对土壤碳通量的总体贡献还不清楚，也不是站点和基因型对其动态的影响，这些因素对于了解可变条件下的养分循环和树木生长至关重要。研究了火炬松（Pinus taedaL.）基因型之间和不同位点之间可能不同。建立了三个火炬松种植园，两个于2009年在北卡罗来纳州（NC）和弗吉尼亚州（VA），一个于2011年在巴西（BR）。2020年，在三个地点和两种基因型之间用土芯估计了根系生物量。季节性和年度细根生产测量在NC和VA网站在第12个生长季节使用向内生长的核心。两年年轻的BR中的树木比NC和VA中的大得多，并且在初始采样时比NC中的细根生物量更大，尽管生育力水平相似。同时，在NC和VA的所有测量地块中，细根生产率随着地上生产率的升高而降低。这些结果表明：（1）立细根生物量可能与不易操纵的环境条件有关，这可以为碳循环建模提供信息;（2）在这些集约管理的地块中，尽管细根生产率较低，但有足够的资源可以增加地上生长，这支持了这些集约造林实践的使用。
Fine roots serve as the primary interface between trees and the soil, and they are dynamic in their response to environmental conditions. Among many functions, they are principle in gathering nutrients and water, and they constitute a major component of the tree. Their overall contribution to soil carbon flux is not well understood, nor is the effect of site and genotype on their dynamics, and these factors are crucial to understanding nutrient cycles and tree growth under variable conditions. This study evaluated how the fine root dynamics of loblolly pine (Pinus taedaL.) might be different between genotypes and on different sites. Three loblolly pine plantations were established, two in 2009 in North Carolina (NC) and Virginia (VA), and one in 2011 in Brazil (BR). Root biomass was estimated with soil cores across the three sites and between two genotypes in 2020. Seasonal and annual fine root production was measured at the NC and VA sites over the 12th growing season using ingrowth cores. The trees in BR that were two years younger were much larger than those in NC and VA and had more fine root biomass at initial sampling than those in NC, despite similar levels of fertility. Meanwhile, fine root production rates decreased with higher rates of aboveground productivity across all measured plots in NC and VA. These results indicate that (1) standing fine root biomass may be related to environmental conditions that are not easily manipulated, which could inform modeling of carbon cycles, and (2) in these intensively managed plots, sufficient resources were available to allow for increased aboveground growth despite lower rates of fine root production, which supports the employment of these intensive silvicultural practices.