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Abstract Understanding the effects of tree species and their mycorrhizal association on soil processes is critical for predicting the ecosystem consequences of species shifts owing to global change and forest management decisions. While it is well established that forests dominated by different mycorrhizal types can vary in how they cycle carbon (C), nitrogen (N) and phosphorus (P), the degree to which these patterns are driven by microbial‐mediated enzyme activity (EA) and ecoenzymatic stoichiometry (ES) remains elusive. Here, we synthesized the effects of mycorrhizal association on seven soil enzymes involved in microbial C, N and P acquisition and ES using data from 56 peer‐reviewed papers. We found that relative to soil in ectomycorrhizal (EcM) trees, soil in arbuscular mycorrhizal (AM) trees exhibited greater activity of some C acquisition enzymes (e.g. beta‐glucosidase; BG) and higher ecoenzymatic ratios of BG/NAG (N‐acetyl‐glucosaminidase) and BG/AP (acid phosphatase). These results supported that AM trees had rapid C and nutrient turnover rates, inorganic nutrient economics and high soil microbial C limitation. We also found evidence for an organic nutrient economy and greater soil microbial demand for nutrients in EcM trees compared to AM trees. In addition, the effect of mycorrhizal association on the activity of certain soil enzymes and enzymatic stoichiometry (i.e. BG and BG/NAG ratio) appeared to be associated with the differences in soil pH, phylogenetic group (i.e. conifers and broadleaves) and leaf habit (i.e. evergreen and deciduous) between AM and EcM trees. The results from the global meta‐analysis suggested that soil EA and ES appear to play critical roles in shaping the differences in the nutrient economy between AM and EcM tree species, but leaf morphology and soil conditions should be considered in evaluations of soil processes in forests of different mycorrhizal associations. Given that most of the studies in the database were from the temperate and subtropical regions, further research in other biomes is needed to elucidate the underlying mechanisms driving the mycorrhizal effect at the global scale. Read the free Plain Language Summary for this article on the Journal blog.
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The motion of trees in the wind: a data synthesis
Abstract. Interactions between wind and trees control energy exchanges between theatmosphere and forest canopies. This energy exchange can lead to thewidespread damage of trees, and wind is a key disturbance agent in many ofthe world's forests. However, most research on this topic has focused onconifer plantations, where risk management is economically important, ratherthan broadleaf forests, which dominate the forest carbon cycle. This studybrings together tree motion time-series data to systematically evaluate thefactors influencing tree responses to wind loading, including data from bothbroadleaf and coniferous trees in forests and open environments. We found that the two most descriptive features of tree motion were (a) the fundamental frequency, which is a measure of the speed at which a treesways and is strongly related to tree height, and (b) the slope of the powerspectrum, which is related to the efficiency of energy transfer from wind totrees. Intriguingly, the slope of the power spectrum was found to remainconstant from medium to high wind speeds for all trees in this study. Thissuggests that, contrary to some predictions, damping or amplificationmechanisms do not change dramatically at high wind speeds, and therefore winddamage risk is related, relatively simply, to wind speed. Conifers from forests were distinct from broadleaves in terms of theirresponse to wind loading. Specifically, the fundamental frequency of forestconifers was related to their size according to the cantilever beam model(i.e. vertically distributed mass), whereas broadleaves were betterapproximated by the simple pendulum model (i.e. dominated by the crown).Forest conifers also had a steeper slope of the power spectrum. We interpretthese finding as being strongly related to tree architecture; i.e. conifersgenerally have a simple shape due to their apical dominance, whereasbroadleaves exhibit a much wider range of architectures with more dominantcrowns.
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- Award ID(s):
- 1700983
- PAR ID:
- 10286813
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Date Published:
- Journal Name:
- Biogeosciences
- Volume:
- 18
- Issue:
- 13
- ISSN:
- 1726-4189
- Page Range / eLocation ID:
- 4059 to 4072
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.5194/bg-18-4059-2021
