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Summary Drying and drought in tropical forests, which have some of the highest net primary productivity on Earth, are likely to alter root dynamics, ecosystem function, and carbon (C) storage.We used a chronic drying experiment in four lowland Panamanian forests to investigate whether soil drying shifts tropical forest root production from surface to deeper soils, where moisture remains more abundant. Furthermore, we explored whether soil drying promotes resource acquisition strategies in roots, such as outsourcing to arbuscular mycorrhizal fungi (AMF) symbionts or increased specific root length (SRL).We found that chronic drying significantly reduced surface root biomass stocks, production, and turnover rates (0–20 cm soil depth), and increased AMF colonization without changes in SRL. Meanwhile, deep fine root productivity (> 60 cm depth) increased in the dry vs wet season, and in the drying experiment, except in the wettest, most infertile forest.Changes in root characteristics in these tropical forests with drying would likely alter forest–climate feedbacks and long‐term soil C storage. At the same time, these results suggest that tropical forests may have an ability to adapt resource acquisition strategies under drying climates.
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This content will become publicly available on November 1, 2026
Experimental deepening of the winter snowpack reduces fine root standing crop at treelines in northwest Alaska
Summary Snow is an important insulator of Arctic soils during winter and may be a source of soil moisture in summer. Changes in snow depth are likely to affect fine root growth and mortality via changes in soil temperature, moisture, and/or nutrient availability, which could alter aboveground growth and reproduction of Arctic vegetation.We explored fine root dynamics at three contrasting treelines in northwest Alaska. We used snowfences to increase snow depth relative to control and minirhizotrons to estimate fine root growth, standing crop, and overwinter loss.Experimental deepening of snowpacks led to warmer winter soils but did not affect growing season soil moisture. Deeper snow reduced fine root standing crop with no significant effects on overwinter fine root loss. Warmer soils in late winter were associated with warmer soils in early and mid‐summer. Warmer early summer soils may have promoted early root growth. However, warmer July soils were associated with reduced fine root growth and smaller standing crops.We hypothesize that deeper snow improves plant access to soil nutrients, resulting in reduced investment in fine roots, potentially leaving additional resources to support aboveground growth and reproduction. Our results suggest one mechanism by which deeper snow could promote northern treeline advance.
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- PAR ID:
- 10651640
- Publisher / Repository:
- New Phytologist Trust
- Date Published:
- Journal Name:
- New Phytologist
- Volume:
- 248
- Issue:
- 4
- ISSN:
- 0028-646X
- Page Range / eLocation ID:
- 1740 to 1755
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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