Time-restricted seed regeneration of Scots pine in sites dominated by feather moss after clear-cutting

• Published in: Canadian Journal of Forest Research
• Main Authors: Nilsson, Marie-Charlotte, Steijlen, Ingeborg, Zackrisson, Olle
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1996
• Subjects: Northern Sweden
• Online Access: http://dx.doi.org/10.1139/x26-104; http://www.nrcresearchpress.com/doi/pdf/10.1139/x26-104

Scots pine (Pinussylvestris L.) were selectively seeded in 1990, 1991, 1992, and 1994 in bottom layer vegetation of Pleuroziumschreberi (Bird.) Mitt, in a clearcut created in 1989 and in an adjacent undisturbed Scots pine forest of Vaccinium type, in northern Sweden. Seedlings from the 1990 seeding established considerably better on the clearcut than in the forest. In contrast, seeding done in 1991, 1992, and 1994 gave no significant difference in seedling establishment between the two sites. Seedlings that established in the clearcut in 1990 grew significantly larger and had a higher content of macro- and micro-nutrients than those in the forest. For seedlings that established in 1992, biomass and nutrient content of seedlings in the clearcut did not differ from those in the forest. Seedlings established in the clearcut in 1990 increased their nutrient content in relation to seed supply, while seedlings established in the clearcut in 1992 and those in the forest had in general gained less or even lost nutrients (especially P) in relation to seed reserve. These results indicate that Pleuroziumschreberi-dominated microsites can constitute a favourable microhabitat for pine regeneration following stand disturbance, although the positive effect quickly diminishes with time after disturbance. The higher establishment and growth of emerging seedlings the 1st year after cutting compared with later established cohorts in the clearcut may be caused by changes in nutrient availability. We propose that environmental stress after cutting temporarily diminishes the effect of the nutrient barrier formed by Pleuroziumschreberi, ericoid mycorrhiza, and ericaceous dwarfshrubs. We conclude that successful natural pine regeneration in Pleuroziumschreberi-dominnted vegetation induced by clear-cutting can be severely time restricted. This is an important consideration when dealing with forestry methods that depend on natural regeneration.