Chestnut Distribution Research Articles

Potential change of chestnut (Castanea sativa Mill.) distribution areas in Kastamonu due to global climate change

Climate change, which is effective on a global scale, threatens almost all living things and ecosystems directly or indirectly. Forests are among the ecosystems that are predicted to be most affected by climate change. In this study, it was aimed to determine the current status of chestnut distribution areas in Kastamonu Forestry Regional Directorate, which is the Forestry Regional Directorate with the highest production in Türkiye, and the change in suitable distribution areas due to global climate change. In the study, in addition to the current suitable distribution areas of chestnut distribution areas and the current distribution area, the suitable distribution areas in 2040, 2070 and 2100 according to SSP 126, SSP 370 and SSP 585 scenarios were determined. The results of the study show that there will be a significant decrease in the suitable distribution areas of chestnut populations in Kastamonu due to the effects of climate change. Therefore, in order to prevent individual, population and species losses in the future, it is recommended to make necessary arrangements in forest management plans by taking the results of the study into consideration.

Impacts of spatial scale and resolution on species distribution models of American chestnut (Castanea dentata) in Pennsylvania, USA

American chestnut (Castanea dentata) was once a foundational tree species of eastern North American hardwood forests before its functional extinction due to an invasive chestnut blight first described at the beginning of the 20th century. Ongoing research to develop a blight-resistant American chestnut through traditional breeding or transgenic means is promising. However, restoration of American chestnut will require a thorough understanding of its spatial distribution and habitat suitability to both find surviving mature trees to enhance the genetic diversity of experimental blight-resistant trees and to identify optimal restoration sites. While many studies have modeled the spatial distribution of American chestnut trees, few have addressed how adjusting spatial scale and resolution impact the predictive ability of species distribution models (SDMs) for the tree species. In this study, we used Maxent to model American chestnut distribution at coarse resolution (238 m) across the state of Pennsylvania and fine resolution (3 m) within French Creek State Park in the southeastern portion of the state. Pennsylvania was chosen as our study area due to its central location in American chestnut’s pre-blight range. Results indicate that the spatial extent of the study area and ranges of environmental variables included in the models influence which variables are most predictive of chestnut distribution. This study suggests that environmental variables such as soil content, soil pH, and elevation are all strong predictors of American chestnut habitat, but their importance varies by resolution. This study also investigates how spatial scale and resolution influence the predictive ability of American chestnut SDMs and offers a workflow for locating restoration sites by first modeling species distribution at a coarse scale and broad extent to identify patches of suitable habitat, then focusing resources on fine scale modeling of species distribution local to those suitable patches.

Ensemble modeling for American chestnut distribution: Locating potential restoration sites in Pennsylvania

The American chestnut (Castanea dentata Borkh.) was an economically, ecologically, and culturally important tree in eastern American hardwood forests. However, the American chestnut is currently functionally absent from these forests due to the introduction of an invasive fungus (Cryphonectria parasitica (Murr.) Barr) and causal agent of chestnut blight in the early 1900s. Field experiments are being carried out to develop a blight-resistant American chestnut tree, but range-wide restoration will require localized understanding of its current distribution and what factors contribute to suitable American chestnut habitat. While previous studies have researched species distribution of the American chestnut, it is important to understand how species distribution modeling (SDM) technique impacts model results. In this paper we create an ensemble model that combines multiple different SDM techniques to predict areas of suitable American chestnut habitat in Pennsylvania. Results indicate that model accuracy varied considerably by SDM technique – with artificial neural networks performing the worst (Area-Under-the-Curve, AUC = 0.705) and gradient boosting models performing the best (AUC = 0.877). Even though SDM technique accuracy varied, most models identified the same environmental variables as the most important: ratio of sand to clay in the soil, canopy cover, topographic convergence index, and topographic position index. This study offers insight into the best SDM techniques to use, as well as a method of combining SDMs for higher prediction confidence.

Modeling the historical distribution of American chestnut (Castanea dentata) for potential restoration in western New York State, US

American chestnut (Castanea dentata) once held great economic and ecological importance in eastern US forests before its demise due to an invasive blight fungus. Backcross breeding and genetic engineering methods are currently developing a blight-resistant tree with mostly American chestnut traits. With the potential reintroduction of chestnut, research has sought to understand the geographic distribution of chestnut to locate potential restoration sites, but less research has compared ideal restoration sites to underlying land ownership. This research models the historical distribution of chestnut in western New York State (NYS, approximately 27,617 km2), containing a portion of the original range of chestnut, in order to determine suitable areas for chestnut reintroduction. This study models chestnut distribution using original land survey record (OLSR) data (ca. 1797–1799 CE) and species distribution models (SDMs), then compares model predictions to current protected lands. Results indicate that depending upon modeling technique, predicted suitable habitat for chestnut ranges 27.9–49.7% of the study area, and that 8.0–11.5% of suitable area is within protected land parcels. SDMs suggest that within the study area, the two predictors most important to chestnut distribution are soil pH and terrain slope, with chestnut favoring acidic soils and steeper slopes. By identifying sites for potential reintroduction of chestnut, this study highlights that reintroduction will depend upon cooperation of private landowners along with governments and non-governmental agencies. This study offers a revision to the historical distribution of chestnut in western NYS, and provides insight into land ownership and management issues facing its restoration.

SPATIO-TEMPORAL CHANGE OF ANATOLIAN CHESTNUT (Castanea sativa Mill.) FORESTS UNDER CLIMATE CHANGE, NORTHEASTERN TURKEY

In this study, the effects of possible climate change in a 36-year period (1980-2015) in different sites on the spatial-temporal distribution of chestnut forests in the Eastern Black Sea region of Turkey were investigated. For this purpose, Giresun, Trabzon-Arsin and Artvin-Hopa in the Eastern Black Sea region were selected as the study areas. The Mann-Kendall and Sen s trend analyses were applied to the annual temperatures (average, maximum and minimum) and annual total precipitations. Two sets of forestry management plans, the first published in 1984-1987 and the second in 2009-2011, were used to extract forest stand maps and to determine change in chestnut distribution. In the time elapsed, chestnut forests increased from 3.58% to 10.05% in Giresun, from 1.28% to 5.31% in Trabzon-Arsin and from 5.44% to 7.53% in Artvin-Hopa. There were increases in chestnut forest areas along with the increasing temperatures. In the city centers, downward shifts occurred in Giresun (-46 m), Trabzon-Arsin (-185 m) and Artvin-Hopa (-168 m) in the minimum altitude against the increasing population. In rural areas, it was determined that there were upward shifts in Giresun (+371 m) and Trabzon-Arsin (+222 m) and downward shifts in Artvin-Hopa (-31 m) in the maximum altitude against the increasing population. Land abandonments and competition between species may have effects on the changes in the area and vertical spread of chestnut forests. However, when the evidences revealed by this study are considered, the changes in temperature and total precipitation in a 30-year period are more likely to affect the spread of chestnut which is a thermophilic species. This study is an exemplary study with respect to carrying out studies on climate change in the region, monitoring chestnut and other species in this regard and developing regional policies for climate change.

The Asian chestnut gall wasp Dryocosmus kuriphilus: a global invader and a successful case of classical biological control

Native to China, the Asian chestnut gall wasp, Dryocosmus kuriphilus (ACGW), was first found outside its native range in Japan and the Korean peninsula in the mid-twentieth century. After appearing in North America in 1974, it was found in Europe a few decades later. Since then, the gall wasp has spread throughout the distribution of chestnut in Europe. The ACGW’s discovery in North America and Europe elicited numerous studies to understand its invasive potential in these areas and how to control its spread and impact on chestnut production. Although endemic parasitoids responded positively to D. kuriphilus with low parasitism rates, the most effective management tactic has been classical biological control via the introduction of the parasitoid Torymus sinensis from its native range in China. This review summarizes the history of introduction, spread, and current distribution of D. kuriphilus, and highlights one of the most successful cases of classical biological control against a forest pest.

Biological Control of Cryphonectria parasitica in Romanian Protected Sweet Chestnut Forests

Asiatic fungus Cryphonectria parasitica has gradually infected all chestnut habitats, forest and horticulture plantations from the most important natural centres of sweet chestnut distribution in Romania. The objectives of this work were to understand the destruction rate of chestnut habitats under C. parasitica pressure, and to test the efficacy of pathogen control in revitalizing these protected forests. Successive inventories of forest health status were carried out in forest districts of Maramures and Gorj counties. C. parasitica biologic control using CHV1 virus has been tested. The methodology includes standard laboratory and field work techniques: local hipervirulent strain identification and conversion to hipovirulence, field canker inoculation, and treatment efficacy evaluation. The fungus killed all mature chestnut trees in roughly two decades. Field inoculation has been successful on chestnut and sessile oak (fungus secondary host) in experimental plots from both target zones. This is the first time in Romania when a forest habitat is recovered by means of biological control, after a severe dieback of the old forest caused by a lethal invasive pathogen.

Airborne castanea pollen forecasting model for ecological and allergological implementation

Castanea sativa Miller belongs to the natural vegetation of many European deciduous forests prompting impacts in the forestry, ecology, allergological and chestnut food industry fields. The study of the Castanea flowering represents an important tool for evaluating the ecological conservation of North-Western Spain woodland and the possible changes in the chestnut distribution due to recent climatic change. The Castanea pollen production and dispersal capacity may cause hypersensitivity reactions in the sensitive human population due to the relationship between patients with chestnut pollen allergy and a potential cross reactivity risk with other pollens or plant foods. In addition to Castanea pollen's importance as a pollinosis agent, its study is also essential in North-Western Spain due to the economic impact of the industry around the chestnut tree cultivation and its beekeeping interest. The aim of this research is to develop an Artificial Neural Networks for predict the Castanea pollen concentration in the atmosphere of the North-West Spain area by means a 20years data set.It was detected an increasing trend of the total annual Castanea pollen concentrations in the atmosphere during the study period. The Artificial Neural Networks (ANNs) implemented in this study show a great ability to predict Castanea pollen concentration one, two and three days ahead. The model to predict the Castanea pollen concentration one day ahead shows a high linear correlation coefficient of 0.784 (individual ANN) and 0.738 (multiple ANN). The results obtained improved those obtained by the classical methodology used to predict the airborne pollen concentrations such as time series analysis or other models based on the correlation of pollen levels with meteorological variables.

Modelling chestnut biogeography for American chestnut restoration

AbstractAim Chestnuts (Castanea spp.) are ecologically and economically important species. We studied the general biology, distribution and climatic limits of seven chestnut species from around the world. We provided climatic matching of Asiatic species to North America to assist the range‐wide restoration of American chestnut [C. dentata (Marsh.) Borkh.] by incorporating blight‐resistant genes from Asiatic species.Location North America, Europe and East Asia.Methods General chestnut biology was reviewed on the basis of published literature and field observations. Chestnut distributions were established using published range maps and literature. Climatic constraints were analysed for the northern and southern distribution limits and the entire range for each species using principal component analysis (PCA) of fourteen bioclimatic variables. Climatic envelope matching was performed for three Chinese species using Maxent modelling to predict corresponding suitable climate zones for those species in North America.Results Chestnuts are primarily distributed in the warm‐temperate and subtropical zones in the northern hemisphere. PCA results revealed that thermal gradient was the primary control of chestnut distribution. Climatic spaces of different species overlap with one another to different degrees, but strong similarities are shown especially between Chinese species and American species. Climatic envelope matching suggested that large areas in eastern North America have a favourable climate for Chinese species.Main conclusions The general biological traits and climatic limits of the seven chestnut species are very similar. The predictions of Chinese species climatic range corresponded with most of the historical American chestnut range. Thus, a regionally adapted, blight‐resistant, introgressed hybrid American chestnut appears feasible if a sufficiently diverse array of Chinese chestnut germplasm is used as a source of blight resistance. Our study provided a between‐continent climate matching approach to facilitate the range‐wide species restoration, which can be readily applied in planning the restoration of other threatened or endangered species.

CHESTNUT AT MIYUN COUNTY OF BEIJING IN CHINA

Miyun County was a main chestnut plantation in Beijing, China. The annual production of Miyun chestnuts was 12,067.9 tons in 2007, making up 54.1% of the total production in Beijing. The study summarized the characters of location, environment, chestnut distribution, nut quality and chestnut development in Miyun, considered problems in current chestnut industry development and put forward some suggestions to promote the sustainable development of chestnut industry and accelerate diversification of chestnut economy.

PHENOTYPIC AND GENETIC DIFFERENCES AMONG POPULATIONS OF EUROPEAN CHESTNUT (CASTANEA SATIVA MILL.) IN SLOVAKIA

Following historical data, localities Bratislava, Jelenec, Modrý Kamen have been considered the three main centers of chestnut distribution in Slovakia. To assess phenotypic and genetic differences among chestnut populations on these localities, randomly selected trees from these populations were subjected to morphometric analysis of 12 fruit traits and analysis of 12 isoensyme systems in winter buds. In addition 71 trees from the progenies, derived from the parental trees of studied populations, were selected to carry out morphometric analysis of fruits. Discriminant analysis of twelve fruit traits showed that separation of three tree sets from localities (populations) was more distinct than separation of the tree sets from groups of progenies. While the tree set from Modrý Kameň (MK) population was only slightly separated in ordination diagram of first two canonical axes the distinct separation of the parental MK population from the other two parental populations was proved by isoenzyme analysis. The MK population deviates by the extent of variation exhibiting a higher level of heterozygozity but lower gene diversity than remaining populations. The surveyed populations are genetically extremely differentiated what suggests they may represent progenies of few mother trees.

Investigating public preferences for managing Lake Champlain using a choice experiment

The Lake Champlain Basin in Vermont and New York, USA and Quebec, Canada includes a large lake and watershed with complex management issues. A transboundary comprehensive management plan prepared for the lake includes 11 goals across many issue areas. We developed a choice experiment to examine public preferences for alternative Lake Champlain management scenarios across these issue areas. Five ecosystem attributes (water clarity–algae blooms, public beach closures, land use change, fish consumption advisories and the spread of water chestnut, an invasive plant) were varied across three levels and arrayed into paired comparisons following an orthogonal fractional factorial design. Two thousand questionnaires were distributed to basin residents, each including nine paired comparisons that required trading off two, three or four attributes. Completed surveys yielded 6541 responses which were analyzed using binary logistic regression. The results showed that although water clarity and beach closures were important, safe fish consumption was the strongest predictor of choice. Land use pattern and water chestnut distribution were weaker but also significant predictors, with respondents preferring less land development and preservation of the agricultural landscape. Current management efforts in the Lake Champlain Basin are heavily weighted toward improving water clarity by reducing phosphorus pollution. Our results suggest that safe fish consumption warrants additional management attention. Because choice experiments provide information that is much richer than the simple categorical judgments more commonly used in surveys, they can provide managers with information about tradeoffs that could be used to enhance public support and maximize the social benefits of an ecosystem management program.

Microsatellite-based characterization of the Castanea sativa cultivar heritage of southern Switzerland

Southern Switzerland has a long tradition of chestnut cultivation as a staple food. Local inhabitants constantly selected varieties according to the ripening period, the type of use, and the adaptability to the territory. As a result, the panorama of chestnut varieties is very complex, as reflected by more than 120 different variety names in an area of 26,000 ha. Since 1994, 47 varieties have been conserved in the chestnut germplasm of southern Switzerland (CSS), including Marroni, Euro-Japanese, and French varieties. A selection of 164 individuals from the CSS was analysed by 8 SSR markers (4 of which were developed in this study). Microsatellite analysis indicated that the CSS was accurately established, as 86% of the individuals grafted were correctly labeled. The identification of 98 genotypes, 10 clonal chestnut groups, 4 synonym groups, and 12 homonym groups reflected the complex ethnogeographical structure of the chestnut distribution. The 17 Marroni individuals considered clustered in 2 differentiated genetic groups instead of only 1 as expected. The fundamental problem of the frequent cases of homonymy and synonymy is discussed, as is the need for criteria for discriminating between polyclonal varieties and distinct homonymous varieties.

Native American influences on the forest composition of the Allegheny Plateau, northwest Pennsylvania

We integrate witness tree distribution, Native American archaeological sites, and geological and topographic variables to investigate the relationships between Native American populations and pre-European settlement forest types on the Allegheny Plateau, northwest Pennsylvania. Detrended correspondence analysis of witness tree data separated the presettlement forests into oak–hickory–chestnut and beech–hemlock–maple communities. Oak, hickory, and chestnut forests were centered on Native American village sites. Using archaeological data, an index of Native American influence (NAI) was derived to reflect the intensity of Native American land use across the landscape. In a comparison among species, mean NAI value of oak, hickory, and chestnut trees was significantly higher than that of beech, maple, and hemlock. Logistic regression demonstrated that among geology type, landform, elevation, aspect, slope, and NAI, NAI was by far the most significant predictor of oak, hickory, and chestnut distribution. Although cause and effect of this relationship cannot be tested, we suggest that long-term Native American activity selected for the disturbance-adapted oak, hickory, and chestnut. We contend that Native American agriculture, burning, and resource extraction could have converted maple–beech–hemlock to oak–hickory–chestnut, or at least reinforced the dominance of this forest type.

Geographic differentiation in adaptive traits of wild chestnut Spanish populations (Castanea sativa Miller)

Flushing, spring frost damages and height were recorded in a provenance test including nineteen populations covering most Spanish chestnut distribution and were analysed to study the differentiation among wild populations. There was remarkable differentiation among populations in flushing time and height growth and Qst was higher for flushing and frost damage, and lower for height. The coefficients of quantitative differentiation among populations were similar to the values obtained for other autochthonous species. Spanish chestnut wild populations were classified in three groups: early flushing xeric populations from the Mediterranean, late flushing populations from northern mountains and intermediate flushing populations from Galician coast and Canary Islands. The observation of variability patterns indicated the importance of natural selection and a restricted gene flow as factors shaping the structure of wild populations in Spain. The use of local sources in plantations was recommended.

Distribution and economic potential of the Sweet chestnut (Castanea sativa Mill.) in Europe

No official and coherent data on the distribution of the European chestnut exist despite its wide range of distribution and the important economic role it has played in many countries. In 1997, in the framework of the COST action G4 “Multidisciplinary Chestnut Research”, quantitative and qualitative data on chestnut forests were collected, mostly from the National Forest Inventories, in order to provide as sound a picture as possible of this important European resource. A total of 2.25 million hectares of forest dominated by chestnut were recorded, with 1.78 million hectares (79.0 %) cultivated for wood and 0.43 million hectares (19.3 %) for fruit production. The remaining 0.04 million hectares (1.7 %) were classified as irregular structures or without any indication. A further 0.31 million hectares are thought to be mixed forest with chestnut. Three types of chestnut countries can be distinguished : (i) countries with a strong chestnut tradition (e.g. Italy, France, southern Switzerland, Spain, Portugal and Greece), where the chestnut stands are cultivated with intensive and characteristic silvicultural systems (coppices and orchards) ; (ii) countries with only a partially developed chestnut tradition due to the country’s particular geography (e.g. England) or history (e.g. Croatia, Turkey, Georgia) ; (iii) countries where the chestnut only sporadically occurs (e.g. Hungary, Bulgaria, Belgium) or has been recently introduced (e.g. Slovakia, Netherlands). A comparison of the present distribution of traditional silvicultural systems and historical data on chestnut distribution supports the hypothesis that the large-scale chestnut forest plantations are of post-Roman origin. Chestnut cultivation is now at a turning point as the changed needs of society have changed as it has moved away from a rural-based to an industrial and urban-oriented organization. The evolution of the chestnut market in recent decades confirms the potential of this resource for both traditional products and new services and goods related to organic-food and environmentally friendly products.

The Present Distribution of Chestnut in the Upland Forest Communities of Virginia

STEPHENSON, S. L., H. S. ADAMS AND M. L. LIPFORD (Department of Biology, Fairmont State College, Fairmont, WV 26554, Division of Arts and Sciences, Dabney S. Lancaster Community College, Clifton Forge, VA 24422, and Division of Natural Heritage, Department of Conservation and Recreation, Richmond, VA 23219). The present distribution of chestnut in the upland forest communities of Virginia. Bull. Torrey Bot. Club 118: 24-32. 1991.-The present distribution of American chestnut (Castanea dentata [Marsh.] Borkh.) as a component of upland forest communities in the mid-Appalachians was investigated in three different areas of western Virginia. Two of these (Alleghany County and the Mountain Lake area of Giles County) are within the Ridge and Valley physiographic province and the third (Shenandoah National Park) is in the Blue Ridge province. Quantitative data on composition and structure of the vegetation and various topographic variables were analyzed using correlation analysis and DCA ordination. The results of these analyses indicate that the present distribution of chestnut is strongly correlated with elevation and site moisture conditions. In general, chestnut was much less abundant (only 192 stems/ha) in Alleghany County (mean elevation of 39 stands = 645 m) than in either Shenandoah National Park (532 stems/ha) or Giles County (770 stems/ha), where sampled stands occur at mean elevations of 882 m (20 stands) and 1079 m (43 stands), respectively. Maximum density of chestnut (>2500 stems/ha for some stands) occurred on subxeric sites, particularly midto upper slope positions on southern exposures. In all three areas, chestnut was conspicuously absent from most mesic sites.

Replacement of native oak and hickory tree species by the introduced American chestnut (Castanea dentata) in southwestern Wisconsin

American chestnut was introduced at West Salem, Wisconsin, about 1880 and had begun to replace native tree species in adjacent oak-hickory woodland before 1930. Chestnut is now an important canopy species over about 20 ha of forested ridge extending north and south of the original plantation. A smaller area of less than 5 ha is dominated by chestnut in both the canopy and understory. Chestnut seedlings and small saplings are more numerous along woodland edges and in recently disturbed soil, they are rare in the interior of ungrazed pasture and entirely absent from intensively grazed areas adjacent to chestnut-dominated woodland. Random sampling of recently established seedlings indicates that from 1 to 5 seedlings/(year ∙ ha) became established in undisturbed woodland between 1986 and 1988. The general pattern of chestnut distribution indicates the importance of woodland edges in chestnut propagation and the effects of livestock grazing in excluding chestnut. Replacement of native species by chestnut appears to have occurred in two steps: isolated groups of trees became established at favorable locations, after which many additional chestnut stems became established in the understory. The recent discovery and treatment of blight indicates that the West Salem site may not be available for study of blight-free chestnut in the future.