Growth and substrate quality of fine root and soil nitroge availability in a young Betula ermanii forest of northern Ja Effects of the removal of understory dwarf bamboo (Sasa kurilensis) S.K. Tripathi a,b, * , A. Sumida b , H. Shibata c , S. Uemura c , K. Ono b , T. Hara b a Department of Botany, Banaras Hindu University, Varanasi 221005, India b The Institute of Low Temperature Science, Hokkaido University, Sapporo 060-819, Japan c Northern Forestry and Development Office, Field Science Center for Northern Biosphere, Hokkaido University, 250 Tokuda, Nayoro 096-0071, Japan Received 18 August 2004; received in revised form 5 January 2005; accepted 30 March 2005 Abstract Dwarf bamboos (mainly Sasa species) form dense undergrowth in many forests in Japan and compete with for soil resources. For a better understanding of the interaction between tree and undergrowth root for soil nu soil N availability, root biomass and its substrate quality in two Betula ermanii stands. In one stand, the aboveground part of undergrowth (Sasa kurilensis) had been removed for 5 years (SR) and in the other, the undergrowth was pres had significantly higher NO 3 -N levels in soil (1.7–5.5 mg kg 1 at different soil depths) than the SP stand (1.2–1.7 mg kg 1 ), which may affect the amount and substrate quality of fine root. Although the total (live + dead) of the root and rhizo not differ between the two stands, the total production by these categories was about half in the SR stand tha the proportion of dead root–rh mass was about two times in the SR stand than the SP stand. In the investigate contribution of the C and N inputs to the total in the uppermost layer (0–10 cm deep) was greater in the SR st SP stand (38–42%). Total root–rh of S. kurilensis in the SP stand contributed to about 38–40% of the total C an SR stand the contribution was still about half that of the SP stand. Further, the acid-insoluble C:N ratio in very root of B. ermanii was significantly less in the SR stand. The contribution of N content in very fine root to the t greater in the SR (45%) stand than the SP stand (36%). These results suggest that the remaining S. kurilensis decreased N use by this species after its removal resulted in increased N availability for B. ermanii. Natural re species after simultaneous death of Sasa species, which is very common in Sasa-dominant forests in Japan, may in part, be facilitated by the presence of residues of the root–rh of Sasa species. # 2005 Elsevier B.V. All rights reserved. Keywords: Fine root; Betula ermanii forest; Understory dwarf bamboo; Biomass production; Substrate quality www.elsevier.com/locate/foreco Forest Ecology and Management 212 (2005) 278–290 * Corresponding author. Tel.: +91 542 244 0206; fax: +91 542 244 0198. E-mail addresses: sk_tripathi@rediffmail.com, tripathi@pop.lowtem.hokudai.ac.jp (S.K. Tripathi). 0378-1127/$ – see front matter # 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.foreco.2005.03.030