Tree rings in high mountain forests represent a valuable natural archive for climate reconstructions and understanding the impact of climate change on forest ecosystems. In this context, the dendroclimatic potential of Alnus acuminata (alder) was evaluated by selecting 25 trees from seven localities in the Mantaro Valley. Computational programs such as Image-Pro Plus, COFECHA, ARSTAN, Sigma Plot, and the IAWA Standard List were utilized. Densitometry, performed with the QTRS-01X equipment using X-ray technology, provided ring width and apparent density diagrams. Seven chronological periods were identified, covering a span of 37.5 years, with the years 1960-1966, 1972-1978, and 2004-2010 showing the greatest growth, and the years 1966-1970, 1980-1986, and 1999-2005 showing the least growth. Furthermore, the alder exhibited particular sensitivity to low winter temperatures in the higher altitude sampling areas. Samples from Colpar 12-A* and Paca 10-A* showed wall thicknesses of 4.39 and 4.60 µm, respectively, attributable to low temperatures. Additionally, a significant negative correlation was observed between minimum temperature and ring width index (r= -0.38, p<0.005) from 1972 to 2008. In terms of precipitation and ring width index, a positive correlation (r= 0.26, p<0.005) was evidenced from 1949 to 2009, positively influencing its development. These findings underscore the dendroclimatic potential of the species, contributing to the understanding of climatic history and the prediction of future conditions in development areas.

Introduction: Long-term climate records are valuable for environmental planning, and tree rings allow records to extend to the time before the establishment of weather stations. For a better understanding of the past climate fluctuation and to mitigate the effect of climate fluctuation, dendroclimatic reconstructions have been applied in many parts of the world. Inter annual variations of climate have an intensive effect on water resources, agriculture, human settlements and regional ecosystems. The central Zagros region of Iran experiences different climatic situations over the seasons of a year. In recent years, dramatic changes in regional climate have damaged both local forests and agriculture. Weather stations cover a short time span of instrumental data in Iran. To overcome this challenge, tree rings can be used to put recent climate trends in a long-term context of climate variability. The central Zagros Mountains are one of the most important sites of oak forest in west of Iran. However, tree-ring based climate reconstructions are still scarce for this country. In this study, we present a reconstruction of temperature variations in the central Zagros Mountains using Quercus infectoria and Quercus persica tree rings over the last 250 years (1750-2010).

Tree ring are one of the most important data sources for reconstructing past climate variability. In order to understand climate variability, it is necessary to get a spatial and temporal coverage of climate information. In dendroclimatology, ring width has been a variable of choice when assessing the tree ring and climate relationships of trees species. We were assessing a ring-width from a dendroclimatic perspective using beech (Fagus orientalis). The aim of this paper is to use tree ring information of Fagus orientalis to assess its capability as a model for reconstruction of Mazandaran province past climate. Therefore, for this purpose tree ring samplings were performed on three selected growing heights of 400, 500, and 700 meters above sea level at northern aspect of Darabcola forest in Mazandaran province. Increment cores were taken from the diameter of breast height (d.b.h.). The rings’ widths were measured using a binocular microscope. Standardization and comparison of tree ring series for each growing elevation were performed for all sites. Radial growth of all Beech tree species in three sites was positively correlated with climatic variables in this regional. Tree Ring chronology show significantly positive correlation with October and December minimum temperature in previous growing season. Maximum temperature in April has inverse relationship with regional chronology. Monthly total precipitation in March and September in current year had positive effect on Radial growth in three sites. Therefore Beech one of the usable species in dendroclimatology studies, this show may can be chronology of Beech extended more than a century in this regional. Also, may can be possible the reconstruction of meteorological data such as mean, minimum and maximum temperature and monthly total precipitation for this region.