•Peripheral forest tree populations face high extinction risks under climate change.•Peripheral forest tree populations result from unusual local adaptation processes.•Peripheral forest tree ...populations harbor valuable evolutionary potential.•Peripheral forest tree populations are key assets for adaptive forestry globally.•Peripheral forest tree populations require an evolution-based management strategy.
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.
•Marginal and peripheral forest populations are key genetic resources.•Expert knowledge on marginality shows subjective perception.•Quantitative indices were developed to identify marginal ...populations.•The developed indices are applicable to any species whose distribution is known.
Marginal and peripheral populations are important for biodiversity conservation. Their original situation in a species’ geographic and ecological space often confers them genetic diversity and traits of high adaptive value. Yet theoretical hypotheses related to marginality are difficult to test because of confounding factors that influence marginality, namely environment, geography, and history. There is an urgent need to develop metrics to disentangle these confounding factors. We designed nine quantitative indices of marginality and peripherality that define where margins lie within species distributions, from a geographical, an environmental and a historical perspective. Using the distribution maps of eight European forest tree species, we assessed whether these indices were idiosyncratic or whether they conveyed redundant information. Using a database on marginal and peripheral populations based on expert knowledge, we assessed the capacity of the indices to predict the marginality status of a population. There was no consistent pattern of correlation between indices across species, confirming that the indices conveyed different information related to the specific geometry of the species distributions. Contrasting with this heterogeneity of correlation patterns across species, the relative importance of the indices to predict the marginality status of populations was consistent across species. However, there was still a significant country effect in the marginality status, showing a variation in expert opinion of marginality vis-á-vis the species distribution. The marginality indices that we developed are entirely based on distribution maps and can be used for any species. They pave the way for testing hypotheses related to marginality and peripherality, with important implications in quantitative ecology, genetics, and biodiversity conservation.
Non-native forest tree species have been introduced in Europe since the 16th century, but only in the second half of the 20th century the significance of the seed source origin for their economic use ...was recognized, resulting in the establishment of numerous provenance trials at a national, regional, European and International level, as those led by IUFRO. Breeding programs have also been launched in the continent for the most economically important species. Aim of this work is the formulation of provenance recommendations for planting of five non-native tree species in Europe (Douglas fir, grand fir, Sitka spruce, lodgepole pine and black locust), based on the information obtained from twenty countries, in the frame of the EU FP-1403 NNEXT Cost Action. The survey revealed that official and non-official national recommendations, based on provenance research results, have been elaborated and followed at a different level and extend for the above five species, but only for Douglas fir recommendations exist in almost all the participating to the survey countries. The compilation of provenance recommendations across Europe for each species is presented in the current work. Besides the recommended introduced seed sources, European seed sources are also preferred for planting, due to ease of access and high availability of forest reproductive material. European breeding programs yielding genetic material of high productivity and quality constitute currently the seed source of choice for several species and countries. Consolidation of trial data obtained across countries will allow the joint analysis that is urgently needed to draw solid conclusions, and will facilitate the development of ‘Universal-Response-Functions’ for the species of interest, rendering possible the identification of the genetic material suitable for global change. New provenance trial series that will test seed sources from the entire climatic range of the species, established in sites falling within and outside the environmental envelopes of their natural ranges, are urgently needed to pinpoint and understand the species-specific climate constraints, as well as to correlate functional traits to the seed origin and the environmental conditions of the test sites, so that the selection of suitable forest reproductive material of non-native tree species in the face of climate change can be feasible.
The Southeastern Europe, which is usually known as Balkan Peninsula, harbours a vast number of plant species among which a great number of relict and endemic ones. This region was one of the main ...areas in Europe where plant species found shelter in refugia and survived during the last glaciation. These refugia were the source areas for the postglacial colonization of many forest tree species. Human impact has been reported in the region since antiquity resulting in fragmentation of forests and deforestation. Marginal/peripheral (MaP) populations could be identified for most of the forest tree species occurring in the region. However, detailed information about MaP populations is restricted to few cases. Most of the MaP populations identified by FP1202 experts are not located in protected areas. Thus, approximately 27 % of the MaP populations are included in Natura 2000 sites, and only one out of the four reported populations is included in a genetic conservation unit. Many MaP populations (40%) are registered as seed stands and only 14% are included in EUFGIS database. Conservation of forest genetic resources, including MaP populations, is a component of sustainable management of forests in many countries of the region.
The conservation and sustainable use of forests and forest genetic resources (FGR) is a challenging task for scientists and foresters. Forest management practices can affect diversity on various ...levels: genetic, species, and ecosystem. Understanding past natural disturbance dynamics and their level of dependence on human disturbances and management practices is essential for the conservation and management of FGR, especially in the light of climate change. In this review, forest management practices and their impact on genetic composition are reviewed, synthesized, and interpreted in the light of existing national and international forest monitoring schemes and concepts from various European projects. There is a clear need and mandate for forest genetic monitoring (FGM), while the requirements thereof lack complementarity with existing forest monitoring. Due to certain obstacles (e.g., the lack of unified FGM implementation procedures across the countries, high implementation costs, large number of indicators and verifiers for FGM proposed in the past), merging FGM with existing forest monitoring is complicated. Nevertheless, FGM is of paramount importance for forestry and the natural environment in the future, regardless of the presence or existence of other monitoring systems, as it provides information no other monitoring system can yield. FGM can provide information related to adaptive and neutral genetic diversity changes over time, on a species and/or on a population basis and can serve as an early warning system for the detection of potentially harmful changes of forest adaptability. In addition, FGM offers knowledge on the adaptive potential of forests under the changing environment, which is important for the long-term conservation of FGR.
Purpose
To evaluate, whether the regional variability of tonsil surgery in terms of the 16 Federal States of Germany was mirrored by a comparable variability of bleeding complications in male and ...female patients.
Methods
A longitudinal population-based inpatient cohort study was performed including all patients who had undergone tonsil surgery between 2005 and 2018. The database was provided by the Federal Statistical Office of Germany and included all inpatient cases after tonsillectomy (with or without adenoidectomy), tonsillotomy, abscess-tonsillectomy and secondary tonsillectomy. The population was stratified by region (16 Federal States) and gender. Operation rates were calculated in relation to the end-year population number of each region. Bleeding percentages were calculated for each calendar year and region as the number of procedures to achieve hemostasis divided by the total number of operations.
Results
The surgical rates varied significantly between the 16 Federal States in male, female and all patients (
p
= 0.001). Revision surgery to achieve hemostasis was predominantly performed in male patients (5.2–11.4% male vs. 3.7–7.6% female patients). Bleeding percentages did not differ significantly from national values in male and female patients in 5 Federal States, but were significantly higher than the national average in 3 Federal States and significantly lower in 7 Federal States for both genders (
p
< 0.05), while in 1 Federal State it was significantly lower only for the male patients. Pearson’s correlation coefficient for surgical and bleeding rates was positive and statistically significant (
p
< 0.05) for all Federal States, except for two. This phenomenon was emphasized by female gender.
Conclusions
Gender had an impact not only on surgical rates but also on bleeding percentages and this was independent from the decrease in the total number of operations. Surprisingly, there was a clear correlation between the rates of both variables in the majority of the Federal States of Germany. It needs further studies to clarify, why a higher prevalence of surgical practice, thus surgical experience, was not followed by lower bleeding complications.
Two intra-provenance Atlantic Coastal (CxC), Piedmont (PxP) and two inter-provenance Atlantic Coastal x Piedmont (CxP), Piedmont x Atlantic Coastal (PxC) loblolly pine (Pinus taeda L.) populations, ...represented by 80 polycross families, were assessed for height, volume, and survival in five Piedmont regions at four years of age. The hybrid populations (CxP, PxC) were intermediate among the pure populations (CxC, PxP). Across and within regions the CxP hybrids were significantly taller and more productive in volume than the pure PxP, with performance comparable to that of CxC. The CxP hybrids exhibited stronger additive genetic control for both height and volume across and within regions, except for the two inland regions, where the PxC hybrids' genetic control for height was stronger. Stability of performance in height and volume varied among families within populations. These early results suggest that the CxP hybrids will perform better in milder Piedmont environments, while the PxC hybrids could be suitable for more inland and northern Piedmont sites. Long-term evaluation of population performance and adaptability is essential before implementing such a plan in the Piedmont.
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•We assessed the impact of genetically enriched material on forests’ resilience.•We compared sixteen selected populations with their reference natural population.•We used three ...comprehensive SNP datasets (overall, common and outlier).•Selected material was significantly differentiated from their original population.•No major genetic diversity loss was detected following genetic selection.•We propose core collections to enrich populations for uncertain future.
Delivering material selected for breeding purposes into the wild in the context of sustainable forest management might reduce the levels of genetic diversity of future forests in comparison to that of natural populations. Another consequence might be a reduction of their resilience under uncertain future climatic and socio-economic conditions if these new populations lack adaptability. Despite the long tradition of breeding activities in Europe, there is still a need to assess the impact of genetically enriched material on forests’ resilience. In this study, we address (1) the genetic diversity of selected material compared to its wild ancestors, and (2) how to enrich breeding material to support forests’ resilience under changing socio-environmental conditions. We analysed 16 study cases of selected material delivered from breeding activities in four European forest tree species (Pinus halepensis Mill., Pinus nigra J.F. Arnold, Pinus pinaster Ait. and Populus nigra L.) with different levels of breeding. To answer these two questions, we first assessed and compared the genetic diversity of selected material versus natural populations using both putatively neutral and adaptive (based on diverging selection) Single Nucleotide Polymorphisms (SNPs). We then suggest how to enrich these populations for resilience under future climatic conditions by defining a core collection for each species including material from populations that will likely disappear under future conditions. Thanks to the large SNP datasets available for our focal species, we were able to detect some trends in our data. Expected and observed heterozygosity values for selected populations were almost always identical. The selected material showed small but significant genetic differentiation from their original population and their inbreeding coefficient was generally lower. However, the level of genetic improvement (i.e. low vs high) was not correlated with the observed genetic differences between selected material and natural populations.The genetic characterization of natural populations distributed across the species range, and the future projection of their range stability, made it possible to identify core-collections that would significantly enrich breeding populations under uncertain future environmental conditions.
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