Extent and distribution of beech (Fagus sylvatica L.) regeneration by adult trees individually dispersed over a spruce monoculture

Abstract

AbsTrAcT:Recently individually dispersed adult beech trees have regenerated in spruce monocultures and this fact could be used to manage the transformation of stands into a mixed forest. Three such cases in the fir-beech and spruce-beech forest zones were analyzed. Beech regeneration is dispersed to distances of several hundred meters regardless of the configuration of the terrain. Using a model we describe this process by a dispersion curve that can be broken up into three sections: (1) directly under the crown as the result of barochory; (2) from 15 to 30 m from the trunk, where the barochoric and zoochoric dispersal of beech nuts intersects; (3) from the "breakpoint" to farther away as a result of zoochory. Regeneration is utilizable as an optimal or at least acceptable method for creating the next economically valuable stands only in sections 1 and 2. In section 3 individual trees may be the central points for the transformation of the second successive forest generation. With spontaneous development without protection from game the density is in the range of hundreds of individuals; in protected groups density can be in the range of tens of thousands of individuals per hectare. The successful regeneration of each tree species is dependent on many favourable circumstances and regeneration is not often successful, even when it is managed using the application of all available biological knowledge. Therefore, the high regeneration potential of beech, which has been recorded approximately over the last twenty years, is noteworthy. It is particularly surprising for the fact that beech advance regeneration that started with just a few isolated individuals has spontaneously penetrated deep into homogenous artificial spruce stands.A similar phenomenon has already been observed and precisely studied in the temperate zone of Europe for oak (pedunculate and sessile oak), wherein they were dispersed to areas far from the regenerating trees. Either they contributed to forest recolonization on abandoned areas and on clearings caused by natural disasters or clear cutting, or they penetrated into forest stands, most frequently pine stands, and started off a spontaneous change in the tree species composition. Interest was above all in how acorns were dispersed. It was discovered that birds play a critical role, mostly jays (Garrulus glandarius)

Ecology of beech regeneration in the allochthonous spruce stands - a case study

“…Mean distance of seedlings dispersion is 12.7 m. The legal number of beech seedling per 1 ha in the czech low (8000 plants per 1 ha) is reached at the distance 1-26 m from the mother tree. These results confi rme other studies (see Unkrig, 1997;Kutter and Gratzer, 2006;Wagner et al, 2010;Dobrovolný and Tesař, 2010b). 3.…”

Density and spatial distribution of beech (Fagus sylvatica L.) regeneration in Norway spruce (Picea abies (L.) Karsten) stands in the central part of the Czech Republic

“…All these observations clearly demonstrate the key role of animals in the dispersion of beech seeds, as already described by other studies (Turček 1961, Kunstler et al 2004, Ganz 2004, Kutter & Gratzer 2006. From the silvicultural point of view, Dobrovolný & Tesar (2010b) consider the threshold of 20 m as the maximum distance between seed trees in order to achieve an adequate density of beech saplings (i.e., a minimum of 10 000 saplings ha -1 ), which is also the standard prescribed by the Czech thinning guideline (Slodičák & Novák 2007). Thus, approximately 2-3 seed trees ha -1 in a spruce stand may provide for up to 30% share of beech regeneration in the subsequent stand generation.…”

“…Few data exist, however, on the use of forest succession elements for management purposes. Remnants of adult individuals and groups of native species, primarily broadleaves (e.g., oak, beech and maple) and/or conifers (such as fir), admixed in pure secondary coniferous stands, can be found both in Europe (Karlsson 2001, Ganz 2004, Kunstler et al 2004, Stimm & Knoke 2004, Dobrovolný & Tesar 2010a, 2010b and in other parts of the world (Hewitt & Kellman 2002a, 2002b. Their potential for spontaneous reproduction differs depending on climatic, site and stand conditions, as well as the silvicultural strategy.…”

“…While Küßner (1997) in the eastern part of the Ore Mts. (Germany) and Diaci (2002) in the Slovenian Alps reported a slow succession of climax woody plants in spruce plantations due to the low number of fruiting individuals within populations, Dobrovolný & Tesar (2010a, 2010b recorded an expansion of beech under the shelter of spruce stands in the Czech Republic and in the central Saxon part of the Ore Mts. (Germany).…”

Growth and characteristics of old beech (Fagus sylvatica L.) trees individually dispersed in spruce monocultures--

“…It was suggested that the potential could be used with an economic advantage especially in the conversion of coniferous monocultures (e.g. Mosandl, Kleinert 1998;Petermann 2000;Ganz 2005;Irmscher 2009;Dobrovolný, Tesař 2010). The idea is not new since already H. Cotta (1763-1844) considered using such trees for the conversion of pure stands into mixed forests immediately in the subsequent stand generation (Hartig 2008).…”