Germinative capacity and energy of critically endangered Ojców birch (Betula oycoviensis Besser) in the Czech Republic

Abstract

Ojców birch (Betula oycoviensis Besser) is a rare and critically endangered taxon of the genus Betula. Its distribution is limited to few countries in Europe. In the Czech Republic, this taxon, characterized by typical shrubby habitus, has been found in fewer than 70 tree individuals, prevailingly in the studied locality Volyně, West Bohemia. This study was focused on the germinative capacity and germinative energy of this taxon, as it is an important indicator of possible regeneration of the trees in nature and for conservation. Non-stratified seeds (2 200 pcs) and stratified ones (2 200 pcs) were compared to each other and in relation to dendrometric tree parameters. The results showed no significant (P > 0.1) differences between stratification variants in total germination (higher by 0.8% in stratified), though stratification improved germinative energy. Germination was in 1st week higher by 6.0% in stratified variant, respectively marginally (P < 0.1) higher in 2nd week in non-stratified variant. However, both germinative capacity and germinative energy were significantly (P < 0.01) variable between individual trees. The germinative capacity was significantly (P < 0.05) positively correlated with tree defoliation. Tiny seeds and triploid trees exhibited very low and zero germinative capacity and energy, respectively. Totally, seeds exhibited sufficient germinative capacity and germinative energy of 23.1% (0.0–62.5%). This suggests that the trees can be potentially used for this type of Ojców birch regeneration i.e. generatively from seeds, although rather in controlled artificial conditions.

Effect of game browsing on natural regeneration of European beech (Fagus sylvatica L.) forests in the Krušné hory Mts. (Czech Republic and Germany)

“…In addition to disadvantages such as the specificity of the time of seeding of the mature stand (Ambrož et al 2015;Vacek et al 2017a), inequality of seedling density (Kantor 2001;Wagner et al 2010) and the restoration of only such species composition that is already in the stand (Poleno et al 2009), natural regeneration has also its advantages. Typical advantages include, for example, ensuring the natural occurrence of genetically native tree species (Korpeľ et al 1991;Gömöry et al 2011;Gallo et al 2020a) that can make use of the local microrelief in an outstanding larch, fir, Douglas fir, pine) (Dittmar et al 2003;Wagner et al 2003Wagner et al , 2010Podrázský et al 2014;Králíček et al 2017;Vacek et al 2019a). In addition, in mixed stands, beech can achieve higher production potential, stability and resistance to extreme weather fluctuations, drought and climate change (Schäfer et al 2017;Pretzsch et al 2021;Vacek et al 2021).…”

Impact of silvicultural system on natural regeneration in Western Himalayan moist temperate forests of Pakistan

“…Suitable ground and site conditions are required for the germination and establishment of seedlings. Site conditions like topography, aspect, moisture availability, humus thickness, light exposure, and grazing activities play a vital role in the germination process (Brewer et al 2012;Vacek et al 2017a;Gallo et al 2020). Forest stand structure and density also affect natural regeneration by allowing the required light and availability of enough seed for germination (Rocha et al 2016;Splawinski et al 2016).…”