Estimates and relationships between aboveground and belowground resource exchange surface areas in a Sitka spruce managed forest

Date

2010

Authors

Butler, Andre
BARBIER, N
ČERMÁK, J
KOLLER, J
THORNILY, C
McEVOY, C
NICOLL, B
PERKS, M P
Grace, J
Meir, Patrick

Journal Title

Journal ISSN

Volume Title

Publisher

Heron Publishing

Abstract

Our knowledge of the nature of belowground competition for moisture and nutrients is limited. In this study, we used an earth impedance method to determine the root absorbing area of Sitka spruce (Picea sitchensis (Bong.) Carr.) trees, making measurements in stands of differing density (2-, 4- and 6-m inter-tree spacing). We compared absorbing root area index (RAIabsorbing; based on the impedance measure) with fine root area index (RAIfine; based on estimates of total surface area of fine roots) and related these results to investment in conductive roots. Root absorbing area was a near-linear function of tree stem diameter at 1.3 m height. At the stand level, RAIabsorbing, which is analogous to and scaled with transpiring leaf area index (maximum stomatal pore area per unit ground area; LAItranspiring), increased proportionally with basal area across the three stands. In contrast, RAIfine was inversely propotional to basal area. The ratio of RAIabsorbing to LAItranspiring ranged from 7.7 to 17.1, giving an estimate of the relative aboveground versus belowground resource exchange areas. RAIabsorbing provides a way of characterizing ecosystem functioning as a physiologically meaningful index of belowground absorbing area.

Description

Keywords

Keywords: carbon; absorption; allometry; basal area; coniferous forest; coniferous tree; ecosystem function; fine root; forest management; functional morphology; leaf area index; moisture; nutrient cycling; nutrient limitation; surface area; article; biomass; ecosy Absorbing root surfaces; Earth impedance; Fine roots; Plant allometry/scaling; RAI:LAI ratio; Root area index

Citation

Source

Tree Physiology

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

DOI

10.1093/treephys/tpq022

Restricted until

2037-12-31