The Role of Fine Roots in the Organic Matter and Nitrogen Budgets of Two Forested Ecosystems

• Charles A. McClaugherty

• John D. Aber

• Jerry M. Melillo

Abstract

Standing crop, rates of production, mortality, decomposition, and nitrogen dynamics of two size classes of fine roots (0—05 mm and 0.5—3.0 mm diameter) were estimated for 1 yr in a 53—yr—old red pine (Pinus resinosa Ait.) plantation and in an adjacent 80—yr—old mixed hardwood stand in north—central Massachusetts. Dry matter of live fine roots was higher in the hardwoods (mean = 6.1 Mg/ha; annual range 3.6—8.6 Mg/ha) than in the plantation (mean = 5.1 Mg/ha; annual range 2.5—7.8 Mg/ha.) Dead root mass was similar in the hardwoods (mean = 4.4 Mg/ha) and the plantation (mean = 4.0 Mg/ha). Nitrogen standing crop of live roots in the hardwoods was higher than in the plantation (mean = 65 kg/ha and 42 kg/ha, respectively). Net fine root production was estimated from changes in standing crop. Production estimates ranged from 4.1 to 11.4 Mg°ha — 1 °yr — 1 in the hardwoods and from 3.2 to 10.9 Mg°ha — 1 °yr — 1 in the plantation, depending on the assumptions made in the calculations. Concurrent estimates of total nitrogen requirement for this production ranged from 73 to 184 kg°ha — 1 °yr — 1 in the hardwoods and from 44 to 122 kg°ha — 1 °yr — 1 in the plantation. Decomposition, measured as mass loss from buried cloth bags, was °20% in 0.4—mm mesh bags and as high as 47% in 3—mm mesh bags after 1 yr. Integrating production and nitrogen requirements with estimates of decomposition rates and nitrogen mineralization for these ecosystems suggested that the lower estimates of production are more accurate.

Journal

• Ecology

  Ecology 63 (5), 1481-1490, 1982-10

  Wiley

Keywords

• Ecology, Evolution, Behavior and Systematics

Details

• CRID: 1362262945225828096
• NII Article ID: 30020883825
• DOI: 10.2307/1938874
• ISSN: 19399170
• ISSN: 00129658
• ISSN: http://id.crossref.org/issn/00129658
• Web Site: http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.2307%2F1938874
• Web Site: https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.2307%2F1938874
• Web Site: https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.2307/1938874
• Data Source:
  • Crossref
  • CiNii Articles