Template-Type: ReDIF-Article 1.0 Author-Name: H. Pretzsch Author-Workplace-Name: Technical University of Munich, Faculty of Forest Science and Resource Management, Chair for Forest Yield Science, Munich, Germany Title: The elasticity of growth in pure and mixed stands of Norway spruce (Picea abies [L.] Karst.) and common beech (Fagus sylvatica L.) Abstract: This study indicates that the growth of mixed stands with Norway spruce (Picea abies [L.] Karst.) and common beech (Fagus sylvatica L.) is more stable across a range of stand densities than it is in pure forests of the same species. Typical density-growth-relationships are derived from 42 long-term experimental areas with 134 plots in total, the oldest of them under survey since 1870. From these results it is apparent that in pure stands maximum growth can be obtained only at medium stand density, whereas in mixed stands growth is almost unchanged over a range of low, medium and high stand density. The finding that mixed stands may perform a superior growth to pure stands with either decreasing or increasing stand density has often been overlooked but is nevertheless of major practical importance. Keywords: elasticity of growth, density-growth-relationship, risk spreading, diversity, productivity, pure and mixed stands Journal: Journal of Forest Science Pages: 491-501 Volume: 49 Issue: 11 Year: 2003 DOI: 10.17221/4721-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/4721-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200311-0001.txt Handle: RePEc:caa:jnljfs:v:49:y:2003:i:11:id:4721-JFS Template-Type: ReDIF-Article 1.0 Author-Name: P. Kantor Author-Workplace-Name: Mendel University of Agriculture and Forestry, Faculty of Forestry and Wood Technology, Brno, Czech Republic Author-Name: V. Hurt Author-Workplace-Name: Mendel University of Agriculture and Forestry, Faculty of Forestry and Wood Technology, Brno, Czech Republic Title: Production potential and ecological stability of mixed forest stands in uplands - V. A mixed spruce/beech stand on a nutrient-rich site of the Křtiny Training Forest Enterprise Abstract: The study is already the 5th account on the production potential and stability of mixed forest stands in uplands. A spruce/beech stand established in the mid-30s of the 20thcentury is assessed. The stand is situated at an altitude of 470 m and since 1960, it is left to its spontaneous development. At that time, the stand was characterized as a silviculturally neglected dense spruce young growth to a small pole-stage stand with an admixture of beech (spruce 71%, beech 13%). In the course of 41 years, spruce proportion in the stand without intentional thinning measures decreased from 71 to 56% and, vice versa, beech proportion increased from 13 to 31%. Present dominant and co-dominant position of spruce in the stand, its health condition and development in recent years indicate that the ecosystem under evaluation is stabilized fulfilling all functions on the given site at an age of 65 years. The stand is permanently fully stocked and its initial standing volume of 109 m3/ha at an age of 24 years in 1960 increased to 560 m3/ha at an age of 65 years in 2001. Keywords: mixed stands, spruce, beech, natural development, production, increment, stability Journal: Journal of Forest Science Pages: 502-514 Volume: 49 Issue: 11 Year: 2003 DOI: 10.17221/4793-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/4793-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200311-0002.txt Handle: RePEc:caa:jnljfs:v:49:y:2003:i:11:id:4793-JFS Template-Type: ReDIF-Article 1.0 Author-Name: S.P. Sah Author-Workplace-Name: Institute of Soil Science and Forest Nutrition, Göttingen, Germany Author-Name: R. Brumme Author-Workplace-Name: Institute of Soil Science and Forest Nutrition, Göttingen, Germany Title: Natural 15N abundance in two nitrogen saturated forest ecosystems at Solling, Germany Abstract: This research deals with a comparative study of two different N-saturated forests: 1. beech forest and 2. spruce forest at the same locality of \solling, Central Germany. The present results show that 15N natural occurrence in the rainfall (both above and below canopy) at Solling site is similar (δ15N = -15‰ to +19‰) to other sites of the world (such as NITREX sites, USA etc.). Furthermore, 15N values in the soil water ranged from -4.32 (± 2.09) to +5‰ (± 1.47), which also corresponds to NITREX sites and other sites of Europe and USA. In both forests, δ15N enrichment of both NH4-N and NO3-N showed a decreasing trend of their values from bulk precipitation to the upper soil layer, but increasing in the deeper soil layer again. An increase in the 15N enrichment of soil water from upper soil depth to lower soil depth was observed in our study and it is assumed to be due to the strong net nitrification taking place in the upper layer (organic surface layer) of soil. The soils at both sites showed characteristic low (negative) δ15N values in the upper organic layers, strongly increasing to positive δ15N values in the mineral soil. In the lower depths of mineral soil horizons of both stands, an increase in δ15N values was found to culminate at +3 to +5‰. In contrast to the mineral soil horizon, in the organic soil horizon (0 to 6 cm depth) of both sites there was almost a similar or slight decrease in δ15N values with depth. This is attributed to the high nitrification rate in the organic soil horizon, resulting in excessive seepage water NO3-output at both sites (especially at the spruce site). Keywords: beech forest, spruce forest, 15N, isotopes, precipitation, soil Journal: Journal of Forest Science Pages: 515-522 Volume: 49 Issue: 11 Year: 2003 DOI: 10.17221/4794-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/4794-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200311-0003.txt Handle: RePEc:caa:jnljfs:v:49:y:2003:i:11:id:4794-JFS Template-Type: ReDIF-Article 1.0 Author-Name: P. Formánek Author-Workplace-Name: Mendel University of Agriculture and Forestry, Faculty of Forestry and Wood Technology, Brno, Czech Republic Author-Name: V. Vránová Author-Workplace-Name: Mendel University of Agriculture and Forestry, Faculty of Forestry and Wood Technology, Brno, Czech Republic Title: The effect of spruce stand thinning on biological activity in soil Abstract: The effect of thinning of young spruce stands by 500 trees/ha on biological activity in the soil profile was studied in the mountainous area of the Moravian-Silesian Beskids. The biological activity of soil was determined under optimal laboratory conditions by tests of soil respiration, catalase activity and intensity of cellulose decomposition. No statistically significant differences were found between the individual biological tests when the two experimental stands were compared (P-level 0.05). All biological activities within each stand were correlated, and significant correlations were found between biological activities in the soil and ammonium nitrogen content. Keywords: spruce, stand density, soil respiration, catalase activity, cellulose decomposition, nitrogen Journal: Journal of Forest Science Pages: 523-530 Volume: 49 Issue: 11 Year: 2003 DOI: 10.17221/4795-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/4795-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200311-0004.txt Handle: RePEc:caa:jnljfs:v:49:y:2003:i:11:id:4795-JFS Template-Type: ReDIF-Article 1.0 Author-Name: M. Sarvaš Author-Workplace-Name: Forest Research Institute Zvolen, Zvolen, Slovak Republic Title: Effect of desiccation on the root system of Norway spruce (Picea abies [L.] Karst.) seedlings and a possibility of using hydrogel STOCKOSORB® for its protection Abstract: The aims of this study were: 1. to determine the effect of dexiccation treatment on the physiological quality of Norway spruce (Picea abies [L.] Karst.) seedlings by measurements of electrolyte leakage from the root system; b) to test the use of hydrogl STOCKOSORB® for protection of the root system of spruce seedlings during their transplanting. The results showed that desiccation treatment significantly affected the rate of electrolyte leakage (34% leakage for control seedlings and 53% in contrast with seedlings after 5 hours of desiccation). Likewise, significant differences were found in height and root collar increments after the first vegetation period that decreased with the duration of desiccation treatment. The values of electrolyte leakage also increased with the duration of desiccation treatment for seedlings treated with hydrogel. On the other hand, the rate of electrolyte leakage was lower after 5 hours of stress factor than in untreated seedlings. The height and root collar increments were higher in seedlings treated with hydrogel for all variants. The obtained results showed a possibility of using the measurement of electrolyte leakage from the root system to determine the physiological quality of Norway spruce seedlings. The rate of electrolyte leakage over 40% signals the physiological damage to the root system of spruce seedlings. Next, the results confirmed the need of protection of seedling roots during handling. The seedlings without hydrogel had 35% height and 26% root collar diameter increment after two-hour desiccation stress. On the other hand, the same seedlings with STOCKOSORB had 42% height and 48% root collar increment. Keywords: desiccation, electrolyte leakage, hydrogel STOCKOSORB® , root system, spruce seedlings Journal: Journal of Forest Science Pages: 531-536 Volume: 49 Issue: 11 Year: 2003 DOI: 10.17221/4796-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/4796-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200311-0005.txt Handle: RePEc:caa:jnljfs:v:49:y:2003:i:11:id:4796-JFS