Regeneration Patterns of European Oak Species (Quercus petraea (Matt.) Liebl., Quercus robur L.) in Dependence of Environment and Neighborhood

Abstract

Quercus robur L. (pedunculate oak) and Quercus petraea (Matt.) Liebl. (sessile oak) are two European oak species of great economic and ecological importance. Even though both oaks have wide ecological amplitudes of suitable growing conditions, forests dominated by oaks often fail to regenerate naturally. The regeneration performance of both oak species is assumed to be subject to a variety of variables that interact with one another in complex ways. The novel approach of this research was to study the effect of many ecological variables on the regeneration performance of both oak species together and identify key variables and interactions for different development stages of the oak regeneration on a large scale in the field. For this purpose, overstory and regeneration inventories were conducted in oak dominated forests throughout southern Germany and paired with data on browsing, soil, and light availability. The study was able to verify the assumption that the occurrence of oak regeneration depends on a set of variables and their interactions. Specifically, combinations of site and stand specific variables such as light availability, soil pH and iron content on the one hand, and basal area and species composition of the overstory on the other hand. Also browsing pressure was related to oak abundance. The results also show that the importance of variables and their combinations differs among the development stages of the regeneration. Light availability becomes more important during later development stages, whereas the number of oaks in the overstory is important during early development stages. We conclude that successful natural oak regeneration is more likely to be achieved on sites with lower fertility and requires constantly controlling overstory density. Initially sufficient mature oaks in the overstory should be ensured. In later stages, overstory density should be reduced continuously to meet the increasing light demand of oak seedlings and saplings.

The Short-Term Effects of Experimental Forestry Treatments on Site Conditions in an Oak–Hornbeam Forest

“…and hornbeam (Carpinus betulus L.) forests were chosen, which represent a deciduous woodland habitat type widespread in the Pannon Ecoregion [48] and generally in Central Europe [49]. This is one of the focal indigenous forest types for timber harvesting in this region, because of the high-quality timber of sessile oak [50]. Here, we focus on the effects of the experimental treatments on site conditions during the first post-harvest period.…”

SOM and Biomass C Stocks in Degraded and Undisturbed Andean and Coastal Nothofagus Forests of Southwestern South America

“…Additionally, in the more degraded forest, the larger the area of bare soil that is exposed to rain and wind erosion has resulted in the formation of small gullies, especially in the Coastal mountains. Similarly, over the previously described transects, the degree of openness and leaf area index (LAI) of the forest canopy were measured every 10 m (Figure 2) for each degradation level (n = 75 hemispherical snapshots per degradation class and 225 snapshots per location) using a Solariscope SOL 300 (Behling, Germany) that was placed at 1.5 m height above the ground [19]. The Solariscope is an innovative instrument that takes hemispherical photographs and subsequently analyzes them for distinct parameters of interest to the user (e.g., direct and indirect sunlight, tree canopy openness).…”

Development of Sessile Oak and European Hornbeam Sprouts after Thinning

“…Sessile oak, as a light-demanding tree species during early development, is considered moderately shade tolerant [16]. Sessile oak represents the main tree species in the uplands of the Czech Republic.…”