Project delays are the major problems tackled by the construction sector owing to the associated complexity and uncertainty in the construction activities. Artificial Intelligence (AI) models have ...evidenced their capacity to solve dynamic, uncertain and complex tasks. The aim of this current study is to develop a hybrid artificial intelligence model called integrative Random Forest classifier with Genetic Algorithm optimization (RF-GA) for delay problem prediction. At first, related sources and factors of delay problems are identified. A questionnaire is adopted to quantify the impact of delay sources on project performance. The developed hybrid model is trained using the collected data of the previous construction projects. The proposed RF-GA is validated against the classical version of an RF model using statistical performance measure indices. The achieved results of the developed hybrid RF-GA model revealed a good resultant performance in terms of accuracy, kappa and classification error. Based on the measured accuracy, kappa and classification error, RF-GA attained 91.67%, 87% and 8.33%, respectively. Overall, the proposed methodology indicated a robust and reliable technique for project delay prediction that is contributing to the construction project management monitoring and sustainability.
•In its natural distribution area Turkish hazel has been overexploited because of its valuable wood and can only be found in small and isolated populations.•Therefore, we examined the genetic ...structure and variation of Turkish hazel covering most of its natural distribution area in Asia Minor, the Caucasus, and the Balkan Peninsula.•Altogether, 689 Turkish hazel trees from 25 populations based on 15 nuclear and five chloroplast microsatellite markers were studied.•Both data sets revealed distinct genetic structures of Turkish hazel in its natural distribution range, suggesting separate refugia and migration pathways during the Holocene.•Medium to high level genetic variation was found, with somewhat lower values in Georgia and Turkey compared to the Balkan populations.•Overall, our results highlight needs to delineate provenance regions, identify conservation units and seed stands for Turkish hazel which are essential for species conservation, provenance research and possible assisted migration attempts.•Based on our results each country is able now to start the conservation programs and select GCUs for Turkish hazel.
Climate change is already affecting all forest ecosystems and threatening species therein. By establishing mixed forests incorporating other tree species (e. g. scattered broadleaves) adaptation of forest stands to changing environmental conditions can be improved and the risks minimized. Turkish hazel (Corylus colurna L.) has been currently discussed as a valuable so-called alternative tree species in some European regions because it is well adapted to difficult environmental conditions. However, in its natural distribution area Turkish hazel has been overexploited because of its valuable wood and can only be found in small and isolated populations. Therefore, we examined the genetic structure and variation of Turkish hazel covering most of its natural distribution range in Asia Minor, the Caucasus, and the Balkan Peninsula. Altogether, 689 Turkish hazel trees from 25 populations were analysed at 15 nuclear and five chloroplast microsatellite markers. Both data sets revealed distinct genetic clusters of Turkish hazel in its natural distribution range, suggesting separate refugia and migration pathways during the Holocene. Medium to high level genetic variation was found, with somewhat lower values in Georgia and Turkey compared to the Balkan populations. Overall, our results highlight the need to delineate provenance regions, identify gene conservation units (GCUs) and seed stands for Turkish hazel which are essential for species conservation, provenance research and possible assisted migration attempts. Based on our results each country is able now to start conservation programs and select GCUs for Turkish hazel.
This paper presents the process of drafting the country report on the state
of forest genetic resources of the Republic of Serbia. The report was drawn
up for the needs of the Second Assessment on ...the State of the World?s Forest
Genetic Resources of the Food and Agriculture Organization of the United
Nations (UN FAO).The paper presents an overview of the objectives,
methodology, sustainability of results, and contribution of the country
report to the forest and nature protection sector, as well as the
integration of national policies into international initiatives for the
conservation of forest genetic resources. The country report contains 32
recommended activities as future steps to improve the situation in the field
of conservation of forest genetic resources and meet the needs for capacity
building and further research. The recommended activities are grouped into
opportunities. Each opportunity is defined as a response to the challenges of
all aspects of the conservation of forest genetic resources. All
recommendations are defined to suit forest owners and users, who can
integrate the conservation of forest genetic resources into forest
management.
The Kunming-Montreal Global Biodiversity Framework recognised the urgency of taking action to conserve intraspecific genetic diversity (IGD) as an insurance against habitat degradation and ...environmental change. Recent work suggests that 90–99 % of IGD should be conserved to safeguard viability of future generations.
Here, we addressed such a conservation issue in three forest tree species in Italy: silver fir (Abies alba Mill.), Heldreich's pine (Pinus heldreichii H. Christ), and pedunculate oak (Quercus robur L.). We used microsatellite markers to measure IGD of 36 (A. alba), 15 (P. heldreichii) and 25 (Q. robur) natural sites, including several putative glacial refugia. We developed a spatial conservation planning (SCP) analysis to quantify the genetic irreplaceability of each site and identify the minimum set coverage ensuring IGD protection. Finally, we compared SCP results with the contributions to allelic diversity within and between sites, total allelic diversity and private allelic richness.
We found that between 44 % and 73 % of sites were required to conserve 90–99 % of the alleles, and that this conservation effort held even when targeting lower percentages of alleles to protect (50–75 %). Glacial refugia were often included in the minimum set coverage, confirming biogeographical expectations. Finally, sites with high genetic irreplaceability were found to have higher private allelic richness on average. These results are discussed in the light of the biogeographic history of the species studied and the current policies for the conservation of forest genetic resources.
•Intraspecific genetic diversity (IGD) must be protected to avoid extirpation.•Spatial conservation planning of IGD in forest trees from a multi-refugial area.•½ to ¾ of sites are to be conserved to achieve adequate protection for IGD.•Setting unambitious conservation targets has limited impact on conservation costs.•Glacial refugia are priority candidates for maximising IGD conservation.
Transposable elements (TEs) are a class of mobile genetic elements that make effects on shaping rapid phenotypic traits of adaptive significance. TE insertions are usually related to transcription ...changes of nearby genes, and thus may be subjected to purifying selection. Based on the available genome resources of
, we found that the composition of Helitron DNA family were highly variable and could directly influence the transcription of nearby gene expression, which are involving in stress-responsive, programmed cell death, and apoptosis pathway. Next, we indicated TEs are highly enriched in
compared with three other congeneric poplar species, especially located at untranslated regions (3'UTRs and 5'UTRs) and Helitron transposons, particularly 24-nt siRNA-targeted, are significantly associated with reduced gene expression. Additionally, we scanned a representative resequenced
population, and identified 9,680 polymorphic TEs loci. More importantly, we identified a Helitron transposon located at the 3'UTR, which could reduce
expression level. Our results highlight the importance of TE insertion events, which could regulate gene expression and drive adaptive phenotypic variation in
.
Community Forest Management in the Maya Biosphere Reserve (MBR; Petén, Guatemala) has been recognized internationally for yielding forest conservation and socioeconomic benefits. However, the effect ...of current timber harvesting practices on the genetic diversity of timber species populations has not previously been documented. This study assessed the effects of timber harvesting on the genetic diversity and viability of regeneration of the most commercially important timber species in the MBR: big-leaf mahogany (Swietenia macrophylla King). Trees and seeds were sampled for two consecutive years in two Forest Management Units of the Multiple Use Zone (MUZ) of the MBR: Cruce a la Colorada and Carmelita. We correlated genetic diversity parameters (as measured using nuclear microsatellites) with seed germination percentages and compared genetic diversity of adults and seeds in stands that had been affected by timber harvesting and those that had not. We found a significant correlation between seed germination percentages (81–83%) and observed heterozygosity (rho=0.27), confirming that genetic diversity is important to regeneration success. No significant differences were found in allelic richness (AR), expected and observed heterozygosity (HE and HO), or inbreeding (FIS), between adults and seeds in harvested vs. undisturbed stands; or before and after timber harvesting. We found low inbreeding levels (FIS=0.040–0.094), low biparental inbreeding (0–0.01), and high outcrossing rates (0.925–0.970) in the populations of S. macrophylla analyzed. Our study therefore provides evidence that genetic diversity in big-leaf mahogany populations was not diminished by one cutting cycle under current practices of community forest management in the MUZ of the MBR.
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.
Protected areas represent an important form of in situ conservation and
sustainable use of forest genetic resources. Compared to other forest
complexes, these areas are less threatened, but they are ...also exposed to
threatening factors that lead to genetic erosion. Bear?ing in mind that the
loss of genetic diversity represents one of the greatest threats to the
pres?ervation of the adaptive potential of species, important for the
survival of forests in conditions of climate change, the conservation of
forest genetic resources can be considered an important activity in all
protected areas. In recent decades, activities on the conservation of the
gene pool of forest species in protected areas in Serbia have been
intensified, and concrete results are already visible in some of them. As an
example of good practice, this paper presents activities on the
identification of rare, endangered, relict, endemic, and vulnerable woody
species in the area of the National Park ?Kopaonik?, in the regime of first
and second degree protection, along with an assessment of their degree of
endangerment. Based on the obtained results, conservation measures of the
available gene pool were proposed, the implementation of which is expected
in the following period.
Germplasm is required to meet the needs of national and international forest restoration programs. Delimitation of germplasm movement zones is an effective tool to address problems of maladaptation ...of these materials but, in Mexico, the current delimitation of seed movement zones defines very heterogeneous areas while the availability of reliable information of the current distribution of species remains insufficient. This study expands and updates the information regarding the potential distribution of eight forest species:
Brosimum alicastrum
,
Bursera simaruba
,
Cedrela odorata
,
Cordia alliodora
,
Cordia dodecandra
,
Ochroma pyramidale
,
Swietenia macrophylla
, and
Tabebuia rosea
, and redefines the germplasm movement zones in seven states of southeastern Mexico, evaluating future changes in the climatic conditions for the time horizons of 2030 and 2060 by combining species distribution modeling techniques and delimitation of germplasm movement zones. Four of the eight predictive variables used in the model construction were determinant in the distribution of all eight species. The germplasm movement zones presented in the Mexican norms and those obtained in the present study differ. The zones of the existing standard are larger and each covers several of the climatic zones proposed in this study, producing seed movement in areas with greater climatic differences. The results suggest a tendency towards an increase in the Refheldt’s aridity index of 2.6 by the year 2060 and of 1.8 °C in the mean temperature of the coldest month, as well as a contraction in the potential distributions of seven of the eight species analyzed over the period 2021–2040.
The recognition of the key role of forests in contrasting the dramatic effects of climate change and biodiversity crisis is the pillar of many initiatives on a global, European, and national scale ...calling for afforestation campaigns. The Italian forest nursery sector is currently inadequate to meet the demand for tree seedlings for the national campaigns. Forest nursery production is characterized by regional or local companies that are remarkably different from each other in organization and efficiency. It is therefore urgent to develop a comprehensive restructuring of the entire sector to be able to respond to the specific needs of forestry projects in Italy and Europe. In this paper, we present a series of key principles and criteria aimed at guiding the renaissance of the sector. Strategic actions are proposed by integrating research, governance, public/private partnership, training, and communication. The strategic approach presented is based on a collaborative structure integrating various skills and responsibilities. The first step is an expert review of the Basic Materials (BM) included in the National Register thanks to the development of the genetic studies of forest stands and the inclusion of shrub and herbaceous species, essentials for ecosystem restoration projects counteracting the biodiversity crisis. A series of actions concerns the aspects of certification, voluntary or prescriptive, of the quality of BM, and the ultimate harmonization of national production to European standards. Particular importance needs to be devoted to the collection, evaluation, and conservation of seeds to develop innovative solutions both for the production of BM and for specific implementation phases of afforestation projects and ecosystem restoration. The governance phase might be implemented through the creation of interregional centers with the duty of collecting and conserving seeds, thus enhancing the existing experiences of outstanding regional and provincial tree nurseries with the support of the National Centers for the study and conservation of Forest Biodiversity. Furthermore, the promotion of partnerships between public and private companies and the creation of a shared and accessible national platform represent strategic actions of primary importance. A fundamental role is then assigned to the implementation of training programs and the construction of an open and incremental communication plan. Thanks to these actions it will be possible to place forest nurseries at the center of the relationships between tree planting and afforestation plans and programs, integrated forest design, implementation of new forests, and their adaptive management.
PDF
