Nesibe Köse

Old World megadroughts and pluvials during the Common Era

An atlas of megadroughts in Europe and in the Mediterranean Basin during the Common Era provides insights into climate variability. Climate model projections suggest widespread drying in the Mediterranean Basin and wetting in Fennoscandia in the coming decades largely as a consequence of greenhouse gas forcing of climate. To place these and other “Old World” climate projections into historical perspective based on more complete estimates of natural hydroclimatic variability, we have developed the “Old World Drought Atlas” (OWDA), a set of year-to-year maps of tree-ring reconstructed summer wetness and dryness over Europe and the Mediterranean Basin during the Common Era. The OWDA matches historical accounts of severe drought and wetness with a spatial completeness not previously available. In addition, megadroughts reconstructed over north-central Europe in the 11th and mid-15th centuries reinforce other evidence from North America and Asia that droughts were more severe, extensive, and prolonged over Northern Hemisphere land areas before the 20th century, with an inadequate understanding of their causes. The OWDA provides new data to determine the causes of Old World drought and wetness and attribute past climate variability to forced and/or internal variability.

Comparative tree-ring anatomy of Fraxinus excelsior with Chalara dieback

We tested the hypothesis that the biometrical characters of wood elements in ash trees (Fraxinus excelsior L.) become modified in response to the progression of disease caused by Chalara fraxinea. Anatomical analyses were performed on wood samples collected at breast height from the trunks of groups of ash trees which contained healthy, weakened and dead trees. We measured (1) tree-ring width, (2) earlywood vessel diameter, (3) earlywood vessel element length, (4) fibre length, (5) fibre diameter, (6) fibre lumen diameter, and (7) fibre wall thickness. We showed that tree-ring width diminished in all analysed groups during disease progression. However, the greatest suppression of growth was observed in dead trees. In both weakened and dead ash trees, the reduction in tree-ring width was accompanied by diminished vessel diameter in the earlywood of the outermost annual rings. The annual rings of dead trees had shorter fibres having greater lumen diameter and thinner cell walls. Consequently, water conduction in the sapwood of dead ash trees was less efficient owing to reduced vessel diameter, and this seems to be one of the greatest disease-induced morphological modifications. All the anatomical modifications might be due to leaf loss and crown dieback triggered by Chalara fraxinea.

What Women Know that Men Do Not about Chestnut Trees in Turkey: A Method of Hearing Muted Knowledge

Abstract. Decades of ethnobotanical observations have shown that knowledge varies significantly according to the identity attributes of participants, such as their religion, occupation, status, income level, geographic origin, and gender. Ethnobiology shares the imperative of all social science disciplines in tailoring gender-responsive methodologies and operating epistemologies. Particularly, researcher identity, performance, and preference for kinds of knowledge may have significant consequences. Here, we present a study centered around an extra effort to engage womens knowledge of sweet chestnut (Castanea sativa) in Turkey. In Turkeys Black Sea, Marmara, and Aegean regions, we conducted 142 extended ethnobotanical interviews with chestnut-utilizing participants using three distinct protocols: gender-unaddressed, men-only, and women-only. Based on participant contributions, we developed and analyzed a dataset which accounted for total reported uses, chestnut material typologies, direct and indirect plant traits, as well as unique and cultural reports. We compared the findings from these distinct protocols using Correspondence Analysis and two-way Analysis of Variance. Our results show that the knowledge reported by women-only was significantly more diverse than knowledge reported under men-only and gender-unaddressed protocols. This significant difference was most readily attributed to the higher frequency of unique and cultural knowledge shared during women-only interviews. Also, considering the routinely mixed-gender conditions under the gender-unaddressed protocol, our findings suggest that male presence, in any form, can mute, or render inadmissible, womens ethnobotanical testimony. These findings challenge the community consensus model of ethnobotanical knowledge and field methodologies that do not account for in-field gender dynamics. In conclusion, we articulate a way to amplify insights from intersectionality theory using ethnobotanical approaches.

Assessment and analysis of rockfall-caused tree injuries in a Turkish fir stand: A case study from Kastamonu-Turkey

Rockfalls can cause serious damage to people, property, facilities and transportation corridors. Furthermore, rockfalls are major hazards in mountain areas with negative impacts on individual trees and forested ecosystems. We conducted a study of rockfall events on 117 mapped (91% of total trees in the stand with > 1.3 m in height and > 5 cm diameter at breast height) Turkish fir trees (Abies bornmuelleriana Mattf.) in a stand within the Kayaarkası-Topçular Village, Inebolu district, Kastamonu province of Turkey. The study site of 0.35 Ha is located on the transition zone of frequently passing rockfall fragments (∼ 40 cm in diameter) generally causing healable injuries. Parameters of trees and injuries were recorded and analysed as to injury number, height and size. Bivariate correlation analysis were used to investigate the relationships between: a) diameter at breast height and number of injuries per tree, b) diameter at breast height and total injury size, c) the number of injuries and total injury size and d) the number of injuries per tree and distance from the source of the rockfall area. Results indicate that the average height of injury, average number of injuries and average injury area to be 81.3 cm (STDEV: 49.8), 7.46 (STDEV: 4.4) and 628.6 cm2 (STDEV: 678.2), respectively. In total 84% of all injuries were recorded within 160° sector at the upslope side of trees and callus tissue that had closed wounds was observed in 79.1% of all injuries. Furthermore 14.5% of injured trees had callus tissue in the process of closing wounds while 6.4% of injuries had not formed any callus tissue. The most common injury types were bark and wood injuries. Bivariate correlation analysis indicated strong relationships between diameter at breast height and the number of injuries (rs = 0.524), injury number and total injury area (rs = 0.653) and distance from rockfall area and injury numbers relations (rs = −0.518). A weaker relationship was found between diameter at breast height and total injury area (rs = 0.363). These results indicate that bigger trees are more prone to rockfall injuries. As expected, trees further from the rockfall area seem to be less prone to rockfall injuries. From our results, it can be inferred that the protection of people and property can be increased through the maintanance of forest in areas immediately below areas prone to rockfall. This stand is still managed in selective forest management system. In order to protect the settlement at the deposition zone it has to manage for protective goals with uneven-aged and multilayered stand structure.