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Belowground Response to Drought in a Tropical Forest Soil. I. Changes in Microbial Functional Potential and Metabolism.

Bouskill NJ, Wood TE, Baran R, Ye Z, Bowen BP, Lim H, Zhou J, Nostrand JD, Nico P, Northen TR, Silver WL, Brodie EL - Front Microbiol (2016)

Bottom Line: This approach reduced soil moisture by 13% and water potential by 0.14 MPa (from -0.2 to -0.34).Previous results from this experiment have demonstrated that the diversity and composition of these soil microbial communities are sensitive to even small changes in soil water.Subsequently, a microbial population emerges with a greater capacity for extracellular enzyme production targeting macromolecular carbon.

View Article: PubMed Central - PubMed

Affiliation: Earth Sciences Division, Ecology Department, Lawrence Berkeley National Laboratory Berkeley, CA, USA.

ABSTRACT
Global climate models predict a future of increased severity of drought in many tropical forests. Soil microbes are central to the balance of these systems as sources or sinks of atmospheric carbon (C), yet how they respond metabolically to drought is not well-understood. We simulated drought in the typically aseasonal Luquillo Experimental Forest, Puerto Rico, by intercepting precipitation falling through the forest canopy. This approach reduced soil moisture by 13% and water potential by 0.14 MPa (from -0.2 to -0.34). Previous results from this experiment have demonstrated that the diversity and composition of these soil microbial communities are sensitive to even small changes in soil water. Here, we show prolonged drought significantly alters the functional potential of the community and provokes a clear osmotic stress response, including the production of compatible solutes that increase intracellular C demand. Subsequently, a microbial population emerges with a greater capacity for extracellular enzyme production targeting macromolecular carbon. Significantly, some of these drought-induced functional shifts in the soil microbiota are attenuated by prior exposure to a short-term drought suggesting that acclimation may occur despite a lack of longer-term drought history.

No MeSH data available.


Related in: MedlinePlus

Ordination showing changing functional potential across the experimental duration. The soils are color-coordinated as either control (red), pre-excluded (green), and de novo soils (blue). The hashed symbols indicate the 3 months sampling point, and the filled symbols represent the 10 months sampling point. The statistical dissimilarity for this ordination can be found in Supplementary Table S2.
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Figure 1: Ordination showing changing functional potential across the experimental duration. The soils are color-coordinated as either control (red), pre-excluded (green), and de novo soils (blue). The hashed symbols indicate the 3 months sampling point, and the filled symbols represent the 10 months sampling point. The statistical dissimilarity for this ordination can be found in Supplementary Table S2.

Mentions: Using functional gene array hybridization we examined the functional potential (i.e., the complement of functional genes within a community) of control and drought soils. Ordination plots of the complete suite of functional genes represented on the Geochip showed that short-term (3-months) drought had a larger impact on the functional potential of the de novo excluded soil microbial communities relative to those in control or pre-excluded soils (Figure 1, Supplementary Table S2). The de novo soils diverged further from controls relative to the pre-excluded soils along both ordination axes. As drought continued (to 10-months), the de novo soil microbial functional potential became significantly different from the control soils and the pre-excluded treatments (Figure 1, Supplementary Figure S1, Supplementary Table S2). Pre-excluded soils at 10 months also became distinct from the control soils, with a functional potential more similar to that of the de novo soils following short-term (3-months) drought.


Belowground Response to Drought in a Tropical Forest Soil. I. Changes in Microbial Functional Potential and Metabolism.

Bouskill NJ, Wood TE, Baran R, Ye Z, Bowen BP, Lim H, Zhou J, Nostrand JD, Nico P, Northen TR, Silver WL, Brodie EL - Front Microbiol (2016)

Ordination showing changing functional potential across the experimental duration. The soils are color-coordinated as either control (red), pre-excluded (green), and de novo soils (blue). The hashed symbols indicate the 3 months sampling point, and the filled symbols represent the 10 months sampling point. The statistical dissimilarity for this ordination can be found in Supplementary Table S2.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837414&req=5

Figure 1: Ordination showing changing functional potential across the experimental duration. The soils are color-coordinated as either control (red), pre-excluded (green), and de novo soils (blue). The hashed symbols indicate the 3 months sampling point, and the filled symbols represent the 10 months sampling point. The statistical dissimilarity for this ordination can be found in Supplementary Table S2.
Mentions: Using functional gene array hybridization we examined the functional potential (i.e., the complement of functional genes within a community) of control and drought soils. Ordination plots of the complete suite of functional genes represented on the Geochip showed that short-term (3-months) drought had a larger impact on the functional potential of the de novo excluded soil microbial communities relative to those in control or pre-excluded soils (Figure 1, Supplementary Table S2). The de novo soils diverged further from controls relative to the pre-excluded soils along both ordination axes. As drought continued (to 10-months), the de novo soil microbial functional potential became significantly different from the control soils and the pre-excluded treatments (Figure 1, Supplementary Figure S1, Supplementary Table S2). Pre-excluded soils at 10 months also became distinct from the control soils, with a functional potential more similar to that of the de novo soils following short-term (3-months) drought.

Bottom Line: This approach reduced soil moisture by 13% and water potential by 0.14 MPa (from -0.2 to -0.34).Previous results from this experiment have demonstrated that the diversity and composition of these soil microbial communities are sensitive to even small changes in soil water.Subsequently, a microbial population emerges with a greater capacity for extracellular enzyme production targeting macromolecular carbon.

View Article: PubMed Central - PubMed

Affiliation: Earth Sciences Division, Ecology Department, Lawrence Berkeley National Laboratory Berkeley, CA, USA.

ABSTRACT
Global climate models predict a future of increased severity of drought in many tropical forests. Soil microbes are central to the balance of these systems as sources or sinks of atmospheric carbon (C), yet how they respond metabolically to drought is not well-understood. We simulated drought in the typically aseasonal Luquillo Experimental Forest, Puerto Rico, by intercepting precipitation falling through the forest canopy. This approach reduced soil moisture by 13% and water potential by 0.14 MPa (from -0.2 to -0.34). Previous results from this experiment have demonstrated that the diversity and composition of these soil microbial communities are sensitive to even small changes in soil water. Here, we show prolonged drought significantly alters the functional potential of the community and provokes a clear osmotic stress response, including the production of compatible solutes that increase intracellular C demand. Subsequently, a microbial population emerges with a greater capacity for extracellular enzyme production targeting macromolecular carbon. Significantly, some of these drought-induced functional shifts in the soil microbiota are attenuated by prior exposure to a short-term drought suggesting that acclimation may occur despite a lack of longer-term drought history.

No MeSH data available.


Related in: MedlinePlus