The role of disturbances in forest regeneration

Abstract

Abstract. The definitions, history and characteristics of disturbances are presented. Natural disturbances are the key processes in forest ecosystems. The establishment of many of the world's forests has been governed by natural disturbances. The list of natural disturbances is very long and varied. They can be split into biotic and abiotic groups: biotic disturbances are caused by insects and pathogens. The most important abiotic disturbances are forest fires, windthrough and floods. In Holling's Model describing the development of ecosystems, natural and anthopogenic disturbances are divided into two groups according to their scale. The first group contains gaps that are created by the death of one or several trees in a forest. The other group consists of the large scale disturbances e.g. forest fires. Examples of gaps and large-scale disturbances in Polish forests are given in the paper. Natural disturbances should be considered as a permanent element of forest ecosystems.

Soil pH and Organic Matter Content Affects European Ash (Fraxinus excelsior L.) Crown Defoliation and Its Impact on Understory Vegetation

“…Ash canopies have higher light penetration than many other tree canopies, resulting in a greater amount of light being available to the understory vegetation. Ash dieback causes increased canopy gaps, and in the gap microsites with increased light availability, further replacement by other tree species [81][82][83]. The changing conditions are likely to lead to changes in the associated understory vegetation [8,84].…”

Is It Possible to Compromise Forest Conservation with Forest Use?

“…Such factors as volcanic eruptions, earthquakes, cosmic rays, hurricanes, fires, and floods can alter the trajectory of forest development and have occurred throughout Earth's history. They cause disruption and provide opportunities for different elements of the environment to develop and so alter biodiversity [19,20].…”

Coordination of morphological and physiological traits in naturally recruited Abies alba Mill. saplings: insights from a structural equation modeling approach

“…To date the survival phase and growth performance of tree saplings are both considered as the key bottleneck in the natural recruitment dynamics of understory saplings (Walters and Reich 2000;Sánchez-Gómez et al 2006). This pattern of recruitment is the result of a wide range of interacting environmental factors that includes yearly variation in micro-site climate, changes in the physical environment (e.g., topography and soils), and different biotic factors (e.g., ungulates browsing, insect, and pathogens attack) (Dobrowolska 2010). Therefore, a pressing challenge in ecological studies is to better understand the complex structure and dynamics of tree recruitment to formulate appropriate silvicultural regime that promote the natural evolutionary processes and maintain heterogeneous conditions, particularly in mixed forest stands (Cater and Levanic 2013).…”