Species distribution models can help predicting range shifts under climate change. The aim of this study is to investigate the late Quaternary distribution of Oriental beech (Fagus orientalis) and to ...project future distribution ranges under different climate change scenarios using a combined palaeobotanical, phylogeographic, and modelling approach. Five species distribution modelling algorithms under the R-package `biomod2`were applied to occurrence data of Fagus orientalis to predict distributions under present, past (Last Glacial Maximum, 21 ka, Mid-Holocene, 6 ka), and future climatic conditions with different scenarios obtained from MIROC-ESM and CCSM4 global climate models. Distribution models were compared to palaeobotanical and phylogeographic evidence. Pollen data indicate northern Turkey and the western Caucasus as refugia for Oriental beech during the Last Glacial Maximum. Although pollen records are missing, molecular data point to Last Glacial Maximum refugia in northern Iran. For the mid-Holocene, pollen data support the presence of beech in the study region. Species distribution models predicted present and Last Glacial Maximum distribution of Fagus orientalis moderately well yet underestimated mid-Holocene ranges. Future projections under various climate scenarios indicate northern Iran and the Caucasus region as major refugia for Oriental beech. Combining palaeobotanical, phylogeographic and modelling approaches is useful when making projections about distributions of plants. Palaeobotanical and molecular evidence reject some of the model projections. Nevertheless, the projected range reduction in the Caucasus region and northern Iran highlights their importance as long-term refugia, possibly related to higher humidity, stronger environmental and climatic heterogeneity and strong vertical zonation of the forest vegetation.
The history of climate is crucially important for any part of the world to understand the nature of climate change. In this context, precipitation reconstruction is still lacking in northern ...Kazakhstan. The purpose of this study is to present a reconstruction for the total precipitation of October of the previous year to July of the current year in northern Kazakhstan.
Pinus sylvestris
L. (Scots pine) forests in Burabai Region are quite important to collect samples to study the climate history. A regional chronology, covering the years of 1702–2014 of
Pinus sylvestris
constructed by using 289/466 trees/cores was used in the reconstruction. The gridded climate data for the years of 1950–2014 were used in the calibration and verification process. High and significant correlations were obtained between tree-ring widths and October to July precipitation in Burabai Region. Based on this significant relationship, reconstruction was performed for the years of 1744–2014. Adjusted
R
2
,
F
-value, sign test, and
r
value were found as 0.38, 39.7 (
P
≤ 0.001), 47+/17, and 0.62 for reconstruction, respectively. The reconstruction showed that 43 dry and 42 wet years occurred during the years of 1744–2014. Only a one-time four-year duration of the wet period was determined covering the years 1978–1981. However, three of six very dry years occurred after the 1950s. As a conclusion, extremity in recent decades is getting an increase in Burabai region.
The Colchic rainforest of the Western Caucasus is one of the few temperate rainforests dominated by broadleaf deciduous trees. Understanding natural dynamics of broadleaf-dominated temperate ...rainforests is essential for their conservation and management. Here, we investigate for the first time the structure, natural disturbance, and recruitment dynamics of a mixed Colchic old-growth rainforest, dominated by Fagus orientalis and Picea orientalis. We used forest inventories and dendrochronological analysis of tree growth in five 30-m-radius plots to quantify forest structure, growth, and disturbances. For the last 400 years, the forest experienced a mixed disturbance regime dominated by frequent small gaps superimposed onto medium disturbances with about a 25-year recurrence period, with no evidences of stand-replacing disturbances. This disturbance regime favored the dominance of shade-tolerant, late successional species with slow tree canopy access through multiple growth releases. These dynamics impose low growth rates and continuous recruitment of spruce and beech, and contributed to a high heterogeneity of tree ages and sizes that result in stable forest structure, as suggested by the low stand slenderness. Spruces were the oldest (up to 427 years) and fastest growing trees in the forest, suggesting that their low presence in the forest is due to low disturbance rates that limit their recruitment. Spring climate conditions that promoted beech growth were detrimental for spruce growth, suggesting that interspecies interactions may condition the effect of climate on forest growth and development. The dynamic equilibrium state we reconstructed in this old-growth forest could likely be disrupted by anthropogenic disturbances or management.
Aim
The Caucasus is a global biodiversity hotspot that includes a wide diversity of temperate forests, from xeric to mesic and rain forest. Little is known about their vulnerability to climate ...change. We aimed to identify the major climate constraints on tree growth.
Location
Western Caucasus of Georgia, Russia and Turkey (40–43° N, 41–43° E).
Time period
Twentieth century.
Major taxa studied
Trees, angiosperms and gymnosperms.
Methods
We used a new network of 35 tree‐ring width chronologies from four angiosperm and four gymnosperm species across an elevational gradient of > 2,000 m. We used correlations to identify the major climate factors (temperature, precipitation and drought) at monthly and seasonal scales affecting tree growth and to assess whether their effects change over time. To explore common response patterns among species, we used self‐organizing maps, a type of artificial neural network.
Results
Spring or summer drought reduced radial growth of most tree species, despite large differences in elevation. As expected, drought was particularly detrimental at warm, low‐elevation sites. Besides drought, growth of conifers at high elevations was also limited by cold winters and summers. Important species‐specific climate–growth responses were also evident. In general, climate–growth relationships were stable over time, except at some cold‐limited sites, where positive responses to summer and winter temperatures have diminished over the last few decades.
Main conclusion
Growth responses to precipitation and drought among species were more similar than they were to temperature, even at humid sites, providing further evidence of drought vulnerability in mesic forests. The productivity of high‐elevation conifer forests, limited by summer drought and low temperatures, will depend on the balance between temperature and precipitation. Given that climate change is expected to induce larger climatic gradients in the region, the potential reduction of forest cover at a regional scale would make the conservation of these mesic forests more essential.
Folk Biological Value and Chestnut Conservation in Turkey.
An ethnobotany dedicated to biocultural survival must advance research methods that perceive and support the biological basis of cultural ...survival in tandem with the cultural basis of biodiversity maintenance. To help address this challenge, we introduce the concept of “folk biological value”—the value of the more-than-human living world to cultural cohesion and survival—as well as a method to investigate and apply it to an ongoing biological conservation endeavor. In Turkey, the sweet chestnut tree population (
Castanea sativa
Mill.) is threatened by multiple exotic pathogens. In order to engage and study the collective value motivating continued chestnut presence and association, we sampled communities along the legible value structure of the value chain. We conducted 162 group interviews with 12 chestnut value chain groups across Turkey. Our results show how botanical knowledge of the tree transforms significantly in correspondence to the flow of the value chain. Further, we demonstrate that while the Black Sea region and western Turkey represent distinct human geographic zones of chestnut engagement, the most substantial countervailing forces defining nationwide conservation priorities are commercial and local maintenance value. This research furthers understanding of and capacity to engage community value during urgent local transitions from ecological protection to prioritization.
We utilize a dataset generated by 17 months of fieldwork, including tree health surveys and ethnobotanical questionnaires, to explore a participant-generated hypothesis that coppiced-tree honey ...collection is eclipsing nut collection as a strategy for the maintenance of chestnut landscapes in the face of increasingly severe pest and disease pressure. We explore this local hypothesis through quantitative analysis of a combined geographic, physiological, and ethnobotanical dataset. We verify participants’ hypothesis and forecast relative success for their projected silvicultural strategy based on outcomes from other contexts. Our findings contribute to emerging consensus in mobility ethnobotany and core flora studies that the increase in importance of plant medicinal value occurs under conditions of rapid change and that valued species enjoy heightened ecological protection in new environments. Further, we highlight the importance of “thinking with” the tension of indigeneity and adaptations required to survive extreme and ubiquitous environmental change, including migration and ecological alteration.
Pinus sylvestris, the most widely distributed pine species, is commonly used in dendrochronological studies. Based on a lack of studies at its southeastern distribution, we analysed the growth ...responses of P. sylvestris to temperature and precipitation. We selected 13 sites to study the effects of climate on the growth of Scots pine stands throughout a geographic gradient over time. Trees were sampled from pure stands at different elevations and landscape conditions. The linear and non-linear associations between tree-ring widths and climate variables were calculated with locally specific linear correlation analysis and a mixed generalised additive model. Moving window correlation function was also performed to understand the temporal stability of limiting factors on growth from 1930 to 2013. Our findings showed that early spring temperature (March-April) and late spring-early summer precipitation (May-June) are the major drivers of growth at all sites, where high temperature constraints and high precipitation enhances the growth. Moving window correlation analysis highlighted that the response to precipitation was stationary while temperature changed over time. Our non-linear analysis provided a threshold for March-April temperature. The threshold indicates that the relative additional increment sharply increases up to 7 °C and then slightly decreases.
•Growth responses to climate in the southernmost limit with the largest tree-ring network.•March-April temperature and May-June precipitation were dominant factors controlling growth.•The relative additional increment sharply increases up to 7 °C and then decreases.•Responses to the precipitation was found linear and stationary.
•We developed the 553-year-long fire history of black pine forests in western Anatolia.•The period of 1853–1934 CE was found as critical fire regime shift period.•A decrease in fire frequency ...observed in the late 19th and early 20th centuries.•Drought and prior wet conditions were main drivers of fires over the past 553 years.
In this study, we aimed to use tree-ring based fire reconstruction to understand the spatiotemporal patterns of past fires in different climate types of western Anatolia. We collected fire scarred wood samples from living trees as wedges and remnant woods from ten sites along a transect that represents a continental to Mediterranean climate gradient. We determined fire years and assigned seasonality of fires based on the intraring position of the fire scars. We calculated fire statistics and analysed fire-climate relationships. Breakpoints in our Anatolian regional fire chronology were estimated to determine the regime shifts. A decrease in fire frequency was recorded at most of the sites after the end of the 19th and the beginning of the 20th century. We observed two critical fire regime shift periods. The period between 1853 and 1934 is characterized by highly frequent (a total of 82 fires) and simultaneous fires occurring in multiple sites and this period overlapped with the longest and most severe drought period of the past 550 years. The fire frequency decline after 1934 coincided with the period of the first forest protection law in 1937. Dry, as well as prior wet conditions were main drivers of fires in the black pine forests in western Anatolia. We observed a decrease in fire frequency in the late 19th and early 20th centuries due to fire suppression activities. Continued fire suppression activities may cause fuel accumulation and pose a risk for more intense fires and thus a paradox for forests in the future. Based on future climate projections, we will face prolonged fire seasons as a consequence of increasing drought frequency, which may shift the fire regime from surface to crown fires with the accumulation of combustible material in the understory in black pine forests.
•We present the first study on tree growth trends in Turkey.•Two different statistical techniques yielded remarkably similar results.•Radial growth of black pine in the Lakes District of Southwest ...Turkey is declining since the 1970s.•This growth decline is likely caused by increased drought stress.
Past and present environmental changes cause significant changes in tree growth in many parts of the world, where both decreasing and increasing growth trends have been detected over the last decades. The Mediterranean basin is especially sensitive to climate change and subsequent tree growth declines. In this article, we present the first study on recent tree growth trends in Turkey. Pinus nigra is a drought-sensitive species and one of the most common and economically important native conifers to Turkey. Tree-ring cores were taken from 61 Pinus nigra plots spread over the entire Lakes District (Southwest Turkey), near the species’ southern range limit. The samples cover the 1839–2013 time period. We apply the Regional Curve Standardization technique and statistical modeling to the tree ring width data to investigate long-term growth trends. Both methods show remarkably similar results: a slowly increasing growth trend until the 1970s, followed by a decreasing trend. This recent negative trend is highly correlated with increased temperature and drought in summer, which suggests that it is likely caused by climate change.
In this study, we identified the most important climate factors affecting the radial growth of black pine at different elevations of the mountain regions of Southwestern Turkey (Sandıras Mountain, ...Muğla/Turkey). We used four black pine tree-ring chronologies, which represent upper and lower distribution limits of black pine forest on the South and North slopes of Sandıras Mountain. The relationships between tree-ring width and climate were identified using response function analysis. We performed hierarchical cluster analysis to classify the response functions into meaningful groups. Black pine trees in the mountain regions of Southwestern Turkey responded positively to a warmer temperature and high precipitation at the beginning of the growing season. As high summer temperatures exacerbated drought, radial growth was affected negatively. Hierarchical cluster analysis made clear that elevation differences, rather than aspect, was the main factor responsible for the formation of the clusters. Due to the mountainous terrain of the study area, the changing climatic conditions (air temperature and precipitation) affected the tree-ring widths differently depending on elevation.
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