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Norby RJ, Warren JM, Iversen CM, Childs J, Jawdy SS, Walker AP. Forest stand and canopy development unaltered by 12 years of CO2 enrichment. TREE PHYSIOLOGY 2022; 42:428-440. [PMID: 34387351 PMCID: PMC8919409 DOI: 10.1093/treephys/tpab107] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 08/05/2021] [Indexed: 06/13/2023]
Abstract
Canopy structure-the size and distribution of tree crowns and the spatial and temporal distribution of leaves within them-exerts dominant control over primary productivity, transpiration and energy exchange. Stand structure-the spatial arrangement of trees in the forest (height, basal area and spacing)-has a strong influence on forest growth, allocation and resource use. Forest response to elevated atmospheric CO2 is likely to be dependent on the canopy and stand structure. Here, we investigated elevated CO2 effects on the forest structure of a Liquidambar styraciflua L. stand in a free-air CO2 enrichment experiment, considering leaves, tree crowns, forest canopy and stand structure. During the 12-year experiment, the trees increased in height by 5 m and basal area increased by 37%. Basal area distribution among trees shifted from a relatively narrow distribution to a much broader one, but there was little evidence of a CO2 effect on height growth or basal area distribution. The differentiation into crown classes over time led to an increase in the number of unproductive intermediate and suppressed trees and to a greater concentration of stand basal area in the largest trees. A whole-tree harvest at the end of the experiment permitted detailed analysis of canopy structure. There was little effect of CO2 enrichment on the relative leaf area distribution within tree crowns and there was little change from 1998 to 2009. Leaf characteristics (leaf mass per unit area and nitrogen content) varied with crown depth; any effects of elevated CO2 were much smaller than the variation within the crown and were consistent throughout the crown. In this young, even-aged, monoculture plantation forest, there was little evidence that elevated CO2 accelerated tree and stand development, and there were remarkably small changes in canopy structure. Questions remain as to whether a more diverse, mixed species forest would respond similarly.
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Affiliation(s)
- Richard J Norby
- Department of Ecology & Evolutionary Biology, University of Tennessee, Knoxville, TN 37996, USA
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Jeffrey M Warren
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Colleen M Iversen
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Joanne Childs
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Sara S Jawdy
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Anthony P Walker
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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Xu H, Xiao J, Zhang Z, Ollinger SV, Hollinger DY, Pan Y, Wan J. Canopy photosynthetic capacity drives contrasting age dynamics of resource use efficiencies between mature temperate evergreen and deciduous forests. GLOBAL CHANGE BIOLOGY 2020; 26:6156-6167. [PMID: 33245613 DOI: 10.1111/gcb.15312] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 08/05/2020] [Accepted: 08/06/2020] [Indexed: 06/11/2023]
Abstract
Forest resource use efficiencies (RUEs) can vary with tree age, but the nature of these trends and their underlying mechanisms are not well understood. Understanding the age dynamics of forest RUEs and their drivers is vital for assessing the trade-offs between forest functions and resource consumption, making rational management policy, and projecting ecosystem carbon dynamics. Here we used the FLUXNET2015 and AmeriFlux datasets and published literature to explore the age-dependent variability of forest light use efficiency (LUE) and inherent water use efficiency as well as their main regulatory variables in temperate regions. Our results showed that evergreen forest RUEs initially increased before reaching the mature stage (i.e., around 90 years old), and then gradually declined; in contrast, RUEs continuously increased with age for mature deciduous forests. Changing canopy photosynthetic capacity (Amax) was the primary cause of age-related changes in RUEs across temperate forest sites. More importantly, soil nitrogen (N) increased in mature deciduous forests through time but decreased in older evergreen forests. The age-dependent changes in soil N were closely linked with the age dynamics of Amax for mature temperate forests. Additionally, soil nutrient conditions played a greater role in deciduous forest RUEs than evergreen forest RUEs. This study highlights the importance of stand age and forest type on temperate forest RUEs over the long term.
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Affiliation(s)
- Hang Xu
- Jixian National Forest Ecosystem Observation and Research Station, CNERN, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation & Desertification Combating, State Forestry and Grassland Administration, Beijing Forestry University, Beijing, China
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | - Jingfeng Xiao
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | - Zhiqiang Zhang
- Jixian National Forest Ecosystem Observation and Research Station, CNERN, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation & Desertification Combating, State Forestry and Grassland Administration, Beijing Forestry University, Beijing, China
| | - Scott V Ollinger
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | | | - Yude Pan
- USDA Forest Service, Northern Research Station, Durham, NH, USA
| | - Jiaming Wan
- Jixian National Forest Ecosystem Observation and Research Station, CNERN, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation & Desertification Combating, State Forestry and Grassland Administration, Beijing Forestry University, Beijing, China
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Rossetti DF, Gribel R, Toledo PM, Tatumi SH, Yee M, Tudela DRG, Munita CS, de Souza Coelho L. Unfolding long-term Late Pleistocene-Holocene disturbances of forest communities in the southwestern Amazonian lowlands. Ecosphere 2018. [DOI: 10.1002/ecs2.2457] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Dilce F. Rossetti
- Brazilian Institute for Space Research-INPE; Rua dos Astronautas 1758 São José dos Campos SP 12245-970 Brazil
| | - Rogério Gribel
- Coordination of Biodiversity; Brazilian National Institute of Amazonian Research-INPA; Av. André Araújo 2936 Manaus AM 69067-375 Brazil
| | - Peter M. Toledo
- Brazilian Institute for Space Research-INPE; Rua dos Astronautas 1758 São José dos Campos SP 12245-970 Brazil
| | | | - Márcio Yee
- Federal University of São Paulo; Santos SP 11070-100 Brazil
| | | | | | - Luiz de Souza Coelho
- Coordination of Biodiversity; Brazilian National Institute of Amazonian Research-INPA; Av. André Araújo 2936 Manaus AM 69067-375 Brazil
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