Foliar maintenance respiration of subalpine and boreal trees and shrubs in relation to nitrogen content

Authors

M.G. Ryan

Document Type

Article

Journal/Book Title/Conference

Plant Cell and Environment

Volume

18

Issue

7

First Page

765

Last Page

772

Publication Date

1995

Abstract

A nitrogen-based model of maintenance respiration (R_m) would link R_m with nitrogen-based photosynthesis models and enable simpler estimation of dark respiration flux from forest canopies. To test whether an N-based model of R_m would apply generally to foliage of boreal and subalpine woody plants, I measured R_m (CO₂ efflux at night from fully expanded foliage) for foliage of seven species of trees and shrubs in the northern boreal forest (near Thompson, Manitoba, Canada) and seven species in the subalpine montane forest (near Fraser, Colorado, USA). At 10°C, average R_m for boreal foliage ranged from 0.94 to 6.8μmol kg⁻¹ s⁻¹ (0.18–0.58 μmol m⁻² s⁻¹) and for subalpine foliage it ranged from 0.99 to 7.6 μmol kg⁻¹ s⁻¹ (0.28–0.64μmol m⁻² s⁻¹). CO₂ efflux at 10°C for the samples was only weakly correlated with sample weight (r = 0.11) and leaf area (r = 0.58). However, CO₂ efflux per unit foliage weight was highly correlated with foliage N concentration [r = 0.83, CO₂ flux at 10°C (mol kg⁻¹ s⁻¹) = 2.62 × foliage N (mol kg⁻¹)J, and slopes were statistically similar for the boreal and subalpine sites (P=0.28). CO₂ efflux per unit of foliar N was 1.8 times that reported for a variety of crop and wildland species growing in warmer climates.

Recommended Citation

RYAN, M.G. (1995), Foliar maintenance respiration of subalpine and boreal trees and shrubs in relation to nitrogen content. Plant, Cell & Environment, 18: 765-772. https://doi.org/10.1111/j.1365-3040.1995.tb00579.x