Aboveground Wood Production Is Sustained in the First Growing Season after Phloem-Disrupting Disturbance

Journal Article · 05 December 2020 · Forests

DOI: https://doi.org/10.3390/f11121306 · OSTI ID:1734643

Grigri, Maxim S. ^[1]; Atkins, Jeff W.  ^[1]; Vogel, Christoph ^[2]; Bond-Lamberty, Ben  ^[3]; Gough, Christopher M.  ^[1]

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1. Virginia Commonwealth Univ., Richmond, VA (United States)
2. Univ. of Michigan, Pellston, MI (United States)
3. Pacific Northwest National Lab. (PNNL), College Park, MD (United States)

Carbon (C) cycling processes are particularly dynamic following disturbance, with initial responses often indicative of longer-term change. In northern Michigan, USA, we initiated the Forest Resilience Threshold Experiment (FoRTE) to identify the processes that sustain or lead to the decline of C cycling rates across multiple levels (0, 45, 65 and 85% targeted gross leaf area index loss) of disturbance severity and, in response, to separate disturbance types preferentially targeting large or small diameter trees. Simulating the effects of boring insects, we stem girdled > 3600 trees below diameter at breast height (DBH), immediately and permanently disrupting the phloem. Weekly DBH measurements of girdled and otherwise healthy trees (n > 700) revealed small but significant increases in daily aboveground wood net primary production (ANPP_w) in the 65 and 85% disturbance severity treatments that emerged six weeks after girdling. However, we observed minimal change in end-of-season leaf area index and no significant differences in annual ANPP_w among disturbance severities or between disturbance types, suggesting continued C fixation by girdled trees sustained stand-scale wood production in the first growing season after disturbance. We hypothesized higher disturbance severities would favor the growth of early successional species but observed no significant difference between early and middle to late successional species’ contributions to ANPP_w across the disturbance severity gradient. We conclude that ANPP_w stability immediately following phloem disruption is dependent on the continued, but inevitably temporary, growth of phloem-disrupted trees. Our findings provide insight into the tree-to-ecosystem mechanisms supporting stand-scale wood production stability in the first growing season following a phloem-disrupting disturbance.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE; National Science Foundation (NSF)
• Grant/Contract Number: AC05-76RL01830; 1655095
• OSTI ID: 1734643
• Report Number(s): PNNL-SA-156853
• Journal Information: Forests, Vol. 11, Issue 12; ISSN 1999-4907
• Publisher: MDPICopyright Statement
• Country of Publication: United States
• Language: English