Microsatellite markers were used to describe the genetic structure of a natural wild cherry (Prunus avium L.) stand in Slovenia. Based on eight analyzed loci, only 67 different multilocus genotypes (MLGs) were identified among 217 trees, indicating a significant amount of clonal reproduction in the stand. Low spatial genetic structure (SGS) was observed in the stand when only sexually derived genets were considered (Sp = 0.011), and the kinship coefficient was only significant in the first distance class (( 40 m). When both the generative and vegetative origin of trees were included, the intensity of the SGS in the stand increased (Sp = 0.149). Forest paths, streams and ditches, which represent obstacles to root growth and consequently obstruct vegetative propagation via root suckers, also affected the spatial grouping of clones in the stand. A relatively high number of somatic mutations within clonal groups were observed, which further increased the complexity of the genetic structure in the stand.
In Europe the area of forested land is increasing, largely due to forest development on abandoned agricultural lands. We compared the structure and composition of woody species in young stands undergoing secondary succession and within gaps of late-successional (LS) forest in Haloze (Slovenia) to derive management options. In a subset of plots in succession, silvicultural measures were carried out in one half, while the other half was left untreated. The attributes of crop trees and their competitor trees were monitored over five years, and a study on the time investment of tending was conducted. We found lower tree density, a larger share of pioneer and shrub species, and a higher diversity of woody plants in succession compared to regeneration within LS forest gaps. Tending resulted in greater density of crop trees, their better social position, fewer competitor trees, and a larger d.b.h. increment, while differences in crop tree stability and quality between tending and control were not confirmed. Our results indicated great structural complexity and species diversity in young successional forests. Their tending represents a cost efficient method of recovering the long-term commercial value and ecosystem services of forests, if applied less intensively than traditional tending of LS forest.
Safeguarding sustainability of forest ecosystems with their habitat variability and all their functions is of highest priority. Therefore, the long-term adaptability of forest ecosystems to a changing environment must be secured, e.g., through sustainable forest management. High adaptability is based on biological variation starting at the genetic level. Thus, the ultimate goal of the Convention on Biological Diversity (CBD) to halt the ongoing erosion of biological variation is of utmost importance for forest ecosystem functioning and sustainability. Monitoring of biological diversity over time is needed to detect changes that threaten these biological resources. Genetic variation, as an integral part of biological diversity, needs special attention, and its monitoring can ensure its effective conservation. We compare forest genetic monitoring to other biodiversity monitoring concepts. Forest genetic monitoring (FGM) enables early detection of potentially harmful changes of forest adaptability before these appear at higher biodiversity levels (e.g., species or ecosystem diversity) and can improve the sustainability of applied forest management practices and direct further research. Theoretical genetic monitoring concepts developed up to now need to be evaluated before being implemented on a national and international scale. This article provides an overview of FGM concepts and definitions, discusses their advantages and disadvantages, and provides a flow chart of the steps needed for the optimization and implementation of FGM. FGM is an important module of biodiversity monitoring, and we define an effective FGM scheme as consisting of an assessment of a forest population’s capacity to survive, reproduce, and persist under rapid environmental changes on a long-term scale.
The fate of peripheral forest tree populations is of particular interest in the context of climate change. These populations may concurrently be those where the most significant evolutionary changes will occur; those most facing increasing extinction risk; the source of migrants for the colonization of new areas at leading edges; or the source of genetic novelty for reinforcing standing genetic variation in various parts of the range. Deciding which strategy to implement for conserving and sustainably using the genetic resources of peripheral forest tree populations is a challenge. Here, we review the genetic and ecological processes acting on different types of peripheral populations and indicate why these processes may be of general interest for adapting forests and forest management to climate change. We particularly focus on peripheral populations at the rear edge of species distributions where environmental challenges are or will become most acute. We argue that peripheral forest tree populations are “natural laboratories” for resolving priority research questions such as how the complex interaction between demographic processes and natural selection shape local adaptation; and whether genetic adaptation will be sufficient to allow the long-term persistence of species within their current distribution. Peripheral populations are key assets for adaptive forestry which need specific measures for their preservation. The traditionally opposing views which may exist between conservation planning and sustainable forestry need to be reconciled and harmonized for managing peripheral populations. Based on existing knowledge, we suggest approaches and principles which may be used for the management and conservation of these distinctive and valuable populations, to maintain active genetic and ecological processes that have sustained them over time.
In the presented case study, we aim to understand the impact of an irregular shelterwood system (ISS) on the genetic diversity of European beech (Fagus sylvatica L.) firstly by comparing managed stand to old growth beech forest and secondly by comparing two successive generations in both managed and old growth stands. Studies on European beech to date have not yet investigated the effect of ISS on its genetic diversity and have rarely addressed the effect of management on the genetic diversity of successive generations. The study was conducted in two mixed beech stands in Slovenia; the unmanaged Rajhenavski Rog old-growth European beech forest reserve and beech forest in Osankarica, managed according to ISS. All 140 sampled adult trees and saplings were genotyped at 16 nuclear microsatellite loci. ISS mimics genetic processes of the old growth rather well in the studied managed stand. The comparisons of diversity measures between managed and old growth stands did not reveal any significant differences between the two for any of the cohorts; the differences between the cohorts from the same stand were not significant. The observed significant shift in allele frequencies at four loci between successive generations could not be unambiguously attributed to management. Cohorts from the same stand had similar genetic structure, but six individuals from the managed stand formed a unique cluster. No convincing evidence of the effect of ISS on genetic diversity of the studied managed beech stand was found.