Insights into Forest Ecosystem Belowground Processes and Functioning in a Changing Environment

23.6K
views
49
authors
8
articles
Editors
4
Impact
Loading...

Introduction: Peatlands are terrestrial-carbon hotspots, where changes in carbon pools and fluxes potentially caused by drying or warming may have significant feedbacks to climate change. In forested peatlands, fine-root biomass (FRB), and production (FRP) are important carbon pools and fluxes, but they and their depth distribution and plant functional type (PFT) composition are poorly known.

Methods: We studied the effects of persistent water-table level (WTL) drawdown on these characteristics in four forested boreal peatland site types that varied in soil nutrient and WTL regimes, ground vegetation and tree stand characteristics. Each site type was represented by a pair of one undrained and one drained site. Two pairs were nutrient-poor, Scots pine dominated sites, one very wet and one relatively dry in their undrained condition. The other two pairs were nutrient-rich, Norway spruce dominated sites, again one wetter and one drier in the undrained condition. FRB was estimated by separating and visually identifying roots from soil cores extending down to 50 cm depth. FRP was estimated using ingrowth cores covering the same depth, and the separated roots were identified using infrared spectroscopy.

Results and discussion: Both FRB and FRP varied widely both within and among the different types of boreal forested peatland. In FRB, the clearest differences were seen in the two originally wettest sites, nutrient-poor tall-sedge pine fen and nutrient-rich herb-rich spruce swamp: FRB was smaller in the drained site compared to the undrained site in the pine fen, but the opposite was true in the spruce swamp. FRP was generally higher in the nutrient-poor, pine-dominated sites than the nutrient-rich, spruce-dominates sites. The depth distribution of FRB was more superficial than that of FRP, except for the most nutrient-rich spruce swamp. Tree and shrub roots dominated both FRB and FRP, except for the undrained pine fen, where graminoids and forbs dominated. Even there, these PFTs were replaced by trees and shrubs at the drained site. Site wetness and nutrient regime both thus clearly regulated FRB and FRP of the forested peatland site types studied, and both need to be considered when making any generalizations.

3,309 views
12 citations
Original Research
26 May 2023

Introduction: Tropical forests harbor a large diversity of closely related tree species that can thrive across habitats. This biodiversity has been found to correspond to large functional diversity in aboveground traits, and likely also relates to belowground trait variation. Globally, root trait (co-)variation is driven by different belowground resource strategies of species, environmental variation, and phylogeny; however, these patterns mostly reflect observations from temperate biomes and remain unconfirmed in tropical trees. We examine phylogenetic and environmental effects on root trait (co-)variation of trees across habitats in an Amazonian rainforest.

Methods: Roots of 218 tree species from ten dominant families were sampled across three major habitats near Manaus, Brazil. We quantified five morphological and architectural root traits to (i) investigate how they reflected different resource strategies across species, (ii) compare them between families and superorders to test phylogenetic effects, and (iii) compare them between habitats to determine environmental effects on root trait expressions and variability.

Results: Root traits discriminated species along a tradeoff between root diameter and root branching and, secondly, due to variation in root tissue density. Our results further show weak phylogenetic effects on tropical tree root variation, for example, families from the same superorder showed large divergence in their root traits, while those from different superorders often overlapped in their root morphology and architecture. Root traits differed significantly between habitats but habitat type had only little effect on overall root trait variation.

Discussion: Our work suggests that the dimensions and drivers that underlie (co-)variation in tropical root traits may differ from global patterns defined by mostly temperate datasets. Due to (a)biotic environmental differences, different root trait dimensions may underlie the belowground functional diversity in (Neo)tropical forests, and we found little evidence for the strong phylogenetic conservatism observed in root traits in temperate biomes. We highlight important avenues for future research on tropical roots in order to determine the degree of, and shifts in functional diversity belowground as communities and environments change in tropical forests.

2,837 views
10 citations
3,732 views
10 citations
Open for submission
Frontiers Logo

Frontiers in Plant Science

Enhancing Woody Plant Growth and Resilience Through Nature-Based Solutions
Edited by Mehrdad Zarafshar, Carmen Arena, Maryam Teimouri
Deadline
18 November 2025
Submit a paper
Recommended Research Topics
Frontiers Logo

Frontiers in Forests and Global Change

Carbon-Nitrogen-Phosphorus Coupling in Forests
Edited by Nicolas Fanin, Marie Spohn, Laurent Augusto
67.3K
views
28
authors
6
articles
Frontiers Logo

Frontiers in Forests and Global Change

Impact of Aboveground Disturbances on Rhizosphere Processes
Edited by Weile Chen, Joanna Mucha
41.4K
views
35
authors
5
articles
Frontiers Logo

Frontiers in Forests and Global Change

Exchanges at the Root-Soil Interface: Resource Trading in the Rhizosphere that Drives Ecosystem Functioning
Edited by Catherine Preece, Erik Verbruggen, Lucia Fuchslueger, Alberto Canarini
32K
views
47
authors
7
articles
Frontiers Logo

Frontiers in Forests and Global Change

Linkages between forest dynamics, soil quality and soil microbial activity
Edited by Mehrdad Zarafshar, Martin Karl-Friedrich Bader, Stéphane Bazot, Yahya Kooch, Maryam Teimouri
15.7K
views
40
authors
6
articles
Frontiers Logo

Frontiers in Forests and Global Change

Forests' Soil-Environment Interactions Under Global Change
Edited by Shri Kant Tripathi, Björn Lennart Berg, Liliana Belokopytova
16.8K
views
29
authors
4
articles