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Common walnut (Juglans regia L) is an economically important species cultivated worldwide for its high-quality wood and nuts. It is generally accepted that after the last glaciation J. regia survived and grew in almost completely isolated stands in Asia, and that ancient humans dispersed walnuts across Asia and into new habitats via trade and cultural expansion. The history of walnut in Europe is a matter of debate, however. In this study, we estimated the genetic diversity and structure of 91 Eurasian walnut populations using 14 neutral microsatellites. By integrating fossil pollen, cultural, and historical data with population genetics, and approximate Bayesian analysis, we reconstructed the demographic history of walnut and its routes of dispersal across Europe. The genetic data confirmed the presence of walnut in glacial refugia in the Balkans and western Europe. We conclude that human-mediated admixture between Anatolian and Balkan walnut germplasm started in the Early Bronze Age, and between western Europe and the Balkans in eastern Europe during the Roman Empire. A population size expansion and subsequent decline in northeastern and western Europe was detected in the last five centuries. The actual distribution of walnut in Europe resulted from the combined effects of expansion/contraction from multiple refugia after the Last Glacial Maximum and its human exploitation over the last 5,000 years.

Common walnut (Juglans regia L) is an economically important species cultivated worldwide for its wood and nuts. It is generally accepted that J. regia survived and grew spontaneously in almost completely isolated stands in its Asian native range after the Last Glacial Maximum. Despite its natural geographic isolation, J. regia evolved over many centuries under the influence of human management and exploitation. We evaluated the hypothesis that the current distribution of natural genetic resources of common walnut in Asia is, at least in part, the product of ancient anthropogenic dispersal, human cultural interactions, and afforestation. Genetic analysis combined with ethno-linguistic and historical data indicated that ancient trade routes such as the Persian Royal Road and Silk Road enabled long-distance dispersal of J. regia from Iran and Trans-Caucasus to Central Asia, and from Western to Eastern China. Ancient commerce also disrupted the local spatial genetic structure of autochthonous walnut populations between Tashkent and Samarkand (Central-Eastern Uzbekistan), where the northern and central routes of the Northern Silk Road converged. A significant association between ancient language phyla and the genetic structure of walnut populations is reported even after adjustment for geographic distances that could have affected both walnut gene flow and human commerce over the centuries. Beyond the economic importance of common walnut, our study delineates an alternative approach for understanding how the genetic resources of long-lived perennial tree species may be affected by the interaction of geography and human history.

A biocultural diversity approach integrates plant biology and germplasm dispersal processes with human cultural diversity. An increasing number of studies have identified cultural factors and ethnolinguistic barriers as the main drivers of the genetic diversity in crop plants. Little is known about how anthropogenic processes have affected the evolution of tree crops over the entire time scale of their interaction with humans. In Asia and the Mediterranean, common walnut (Juglans regia L.) and sweet chestnut (Castanea sativa Mill.) have been economically and culturally important crops for millennia; there, in ancient times, they were invested with symbolic and religious significance. In this study, we detected a partial geographic congruence between the ethno‐linguistic repartition of human communities, the distribution of major cognitive sets of word‐related terms, and the inferred genetic clusters of common walnut and sweet chestnut populations across Eurasia. Our data indicated that isolation by distance processes, landscape heterogeneity and cultural boundaries might have promoted simultaneously human language diversification and walnut/chestnut differentiation across the same geographic macro‐regions. Hotspots of common walnut and sweet chestnut genetic diversity were associated with areas of linguistic enrichment in the Himalayas, Trans‐Caucasus, and Pyrenees Mountains, where common walnuts and sweet chestnuts had sustained ties to human culture since the Early Bronze Age. Our multidisciplinary approach supported the indirect and direct role of humans in shaping walnut and chestnut diversity across Eurasia from the EBA (e.g., Persian Empire and Greek–Roman colonization) until the first evidence of active selection and clonal propagation by grafting of both species. Our findings highlighted the benefit of an efficient integration of the relevant cultural factors in the classical genome (G) × environmental (E) model and the urgency of a systematic application of the biocultural diversity concept in the reconstruction of the evolutionary history of tree species. Little is known about how anthropogenic processes have affected the evolution of tree species with a long‐time‐scale history of human utilization such as common walnut (Juglans regia L.) and sweet chestnut (Castanea sativa Mill.). In this study, we evaluated the impact of isolation by distance processes, landscape heterogeneity, and cultural boundaries among human communities on shaping genetic resources of walnut and chestnut across Eurasia. Our findings highlighted the benefit of an efficient integration of the relevant cultural factors in the classical genome (G) × environmental (E) model and the urgency of a systematic application of the biocultural diversity concept in the reconstruction of evolutionary history of tree species

Persian walnut (Juglans regia L) is an economically important species cultivated worldwide for its wood and nuts. Despite the increasing interest in the development of conservation strategies for walnut germplasm, an accurate and full-scale overview of wild genetic resources of J. regia has not been conducted because natural populations are located in regions of Asia historically difficult to access. In this study, we estimated the genetic diversity and spatial genetic structure of 39 autochthonous Persian walnut populations sampled across its Asian range using 14 neutral microsatellite markers. A landscape genetic overlay approach was applied to detect the areas of current reservoirs of walnut genetic diversity in the Asian range and to evaluate the role of landscape in shaping walnut genetic diversity since the Last Glacial Maximum. Although Persian walnut has been highly manipulated by humans over the last 2,000 years, we determined that patches of high genetic diversity still exist in the Caucasus and mountains of Central Asia where J. regia might have survived after Pleistocene glaciations. We detected a clear separation of Persian walnut into four main genetic clusters centered in (1) western Kyrgyzstan, (2) western and south–central Asia, (3) east–central Uzbekistan, and (4) Xinjiang and Shandong provinces (China). Overlay of maps showed a coincidence between groups of walnut populations and potential barriers to gene flow such as the Hindu Kush, Pamir, Tien Shan, and Himalaya mountains and the Karakum, Kyzyl Kum, and Taklamakan deserts. This study claimed the relevance of the preservation of walnut genetic resources in the Asian range.

Woodland creation has become an important objective for a variety of stakeholders to help tackle the climate and biodiversity crises. One of the key evidence needs is a better understanding of the multiple factors influencing the willingness and ability of landowners and managers to establish new woodlands. To address this gap, a systematic map of evidence was prepared comprising publications from academic journals and grey literature accessed through bibliographic databases (Web of Science, Scopus, and CAB Abstracts), libraries, direct requests to relevant organisations and individuals, and citation tracking from past reviews. A screening process refined the evidence base to 226 studies within the UK. The systematic evidence map codes the content of each study against a comprehensive list comprising actors, drivers of or barriers to woodland creation, and outcomes. These are presented as a freely accessible, interactive online dashboard detailing sources of evidence. The systematic evidence map helps users navigate the evidence, demonstrating where the bulk of the evidence lies and, conversely, several evidence gaps where there is comparatively little evidence. The findings serve as a basis for dialogue with stakeholders to determine priorities for future primary research.

Common walnut (Juglans regia L) is an economically important species cultivated worldwide for its high-quality wood and nuts. It is generally accepted that after the last glaciation J. regia survived and grew in almost completely isolated stands in Asia, and that ancient humans dispersed walnuts across Asia and into new habitats via trade and cultural expansion. The history of walnut in Europe is a matter of debate, however. In this study, we estimated the genetic diversity and structure of 91 Eurasian walnut populations using 14 neutral microsatellites. By integrating fossil pollen, cultural, and historical data with population genetics, and approximate Bayesian analysis, we reconstructed the demographic history of walnut and its routes of dispersal across Europe. The genetic data confirmed the presence of walnut in glacial refugia in the Balkans and western Europe. We conclude that human-mediated admixture between Anatolian and Balkan walnut germplasm started in the Early Bronze Age, and between western Europe and the Balkans in eastern Europe during the Roman Empire. A population size expansion and subsequent decline in northeastern and western Europe was detected in the last five centuries. The actual distribution of walnut in Europe resulted from the combined effects of expansion/contraction from multiple refugia after the Last Glacial Maximum and its human exploitation over the last 5,000 years.

Common walnut (Juglans regia L) is an economically important species cultivated worldwide for its wood and nuts. It is generally accepted that J. regia survived and grew spontaneously in almost completely isolated stands in its Asian native range after the Last Glacial Maximum. Despite its natural geographic isolation, J. regia evolved over many centuries under the influence of human management and exploitation. We evaluated the hypothesis that the current distribution of natural genetic resources of common walnut in Asia is, at least in part, the product of ancient anthropogenic dispersal, human cultural interactions, and afforestation. Genetic analysis combined with ethno-linguistic and historical data indicated that ancient trade routes such as the Persian Royal Road and Silk Road enabled long-distance dispersal of J. regia from Iran and Trans-Caucasus to Central Asia, and from Western to Eastern China. Ancient commerce also disrupted the local spatial genetic structure of autochthonous walnut populations between Tashkent and Samarkand (Central-Eastern Uzbekistan), where the northern and central routes of the Northern Silk Road converged. A significant association between ancient language phyla and the genetic structure of walnut populations is reported even after adjustment for geographic distances that could have affected both walnut gene flow and human commerce over the centuries. Beyond the economic importance of common walnut, our study delineates an alternative approach for understanding how the genetic resources of long-lived perennial tree species may be affected by the interaction of geography and human history.

A range-wide collection of Juglans regia seeds was undertaken in autumn 1997 from 12 countries, including 25 provenances and 375 half-sib progenies. 2200 seedlings were produced using innovative nursery techniques. The seedlings were planted in three provenance trials in southern England in 1999, the largest of which acted as a combined provenance/progeny trial. After one growing season, survival was 98.9 %, mean height growth 35 cm, and mean stem diameter increment 5 mm. Provenance differences for both height and stem diameter increment were highly significant (p<0.001). There were no significant genotype × environment interactions. Flushing assessments revealed few significant differences between provenances and flushing was complete by early April. Family heritability for tree height was 0.19 at one site and, with combined selection, genetic gain was estimated at 8 %. The effects of three types of treeshelter and a stumping treatment on walnut establishment were tested over three growing seasons. Treeshelters were found beneficial to height increment. However, 120 cm tall shelters promoted early flushing, and consequent risk of increased frost damage, and caused more stem die-back than 75 cm shelters. Stumping promoted rapid early height increment but gave no longer-term benefit. The crown (cd) and stem (dbh) diameter at breast height relationship of open growing trees in Britain was assessed and was highly significant (r2 = 0.96, p<0.001). The regression equation (cd = 2.71 + 17.6dbh) permitted the estimation of suitable planting densities for the provenance trials and the calculation of a thinning regime. Isozyme analysis of the 375 genotypes identified 20 loci in 15 enzyme systems with seed embryo extracts. Using young leaf extracts, the polymorphic locus Pgm-1 indicated low expected heterozygosity of 0.06 both within populations and at the species level. FST and GST estimates, both 0.05, indicated high uniformity among populations. Genetic distance estimates did not identify significant clustering consistent with geographic origin.

Extensive natural forests of common walnut, Juglans regia L., occur in the mountains of Kyrgyzstan in Central Asia. These remote forests are likely to be an important genetic resource for J. regia, not only for in situ conservation, but also as a resource for tree breeding. The origins, environmental conditions and current health of the Kyrgyz walnut forests, which are increasingly under threat, are discussed. A British-based research project has made eleven provenance collections from Kyrgyzstan, which in combination with nine provenances from other countries, will be tested in British conditions. Studies of genetic diversity are being undertaken to assess intraspecific variation in walnut, both in Kyrgyzstan and across the remainder of the natural and introduced ranges. Des forêts naturelles étendues du noyer commun, Juglans regia L., existent dans les montagnes de Kirghizistan en Asie Centrale. Ces forêts lointaines seront probablement une ressource génétique importante pour J. regia, non seulement pour la conservation in situ, mais encore comme une ressource pour la propagation arboricole. On traite des origines, des conditions environnementales et de l'état actuel de santé des forêts de noyer Kirghizes, qui sont de plus en plus menacées. Un projet de recherche basée en Grande Bretagne a fait onze collections de provenance de Kirghizistan, qui seront testées, avec neuf provenances d'autres pays, sous les conditions britanniques. On étudie la diversité génétique pour évaluer la variation intraspécifique du noyer, en Kirghizistan et dans le reste des aires de répartition naturelle et artificielle. Existen en las montañas de Kyrgyzstan en Asia Central, bosques naturales extensivos de nogal común, Juglans regia L. Estos bosques remotos son probablemente un recurso genético importante para J. regia, no solamente para la conservación in situ, sino también como un recurso para la selección y el mejoramiento de árboles. Se discuten los orígenes, condiciones ambientales y la salud actual de los bosques de nogal de Kyrgyz, que están bajo amenaza en forma creciente. Un proyecto de investigación basado en Gran Bretaña ha hecho once colecciones de procedencias de Kyrgyzstan, que se probarán bajo condiciones británicas, en combinación con nueve procedencias de otros países. Se están emprendiendo estudios de diversidad genética para la evaluación intra-específica en el nogal, tanto en Kyrgyzstan como a través del resto de su rango natural y zonas de introducción.

Understanding the environmental effects of marine energy (ME) devices is fundamental for their sustainable development and efficient regulation. However, measuring effects is difficult given the limited number of operational devices currently deployed. Numerical modeling is a powerful tool for estimating environmental effects and quantifying risks. It is most effective when informed by empirical data and coordinated with the development and implementation of monitoring protocols. We reviewed modeling techniques and information needs for six environmental stressor–receptor interactions related to ME: changes in oceanographic systems, underwater noise, electromagnetic fields (EMFs), changes in habitat, collision risk, and displacement of marine animals. This review considers the effects of tidal, wave, and ocean current energy converters. We summarized the availability and maturity of models for each stressor–receptor interaction and provide examples involving ME devices when available and analogous examples otherwise. Models for oceanographic systems and underwater noise were widely available and sometimes applied to ME, but need validation in real-world settings. Many methods are available for modeling habitat change and displacement of marine animals, but few examples related to ME exist. Models of collision risk and species response to EMFs are still in stages of theory development and need more observational data, particularly about species behavior near devices, to be effective. We conclude by synthesizing model status, commonalities between models, and overlapping monitoring needs that can be exploited to develop a coordinated and efficient set of protocols for predicting and monitoring the environmental effects of ME.