Climatic response of tree-ring densitometric records in a semiarid site of China

2020 ◽  
Author(s):  
Huiming Song ◽  
Yu Liu
Keyword(s):  
Tree Ring ◽  
Tree Growth ◽  
Monsoon Season ◽  
Growing Season ◽  
Moisture Stress ◽  
Maximum Density ◽  
Semiarid Region ◽  
Summer Temperatures ◽  
Positive Correlations ◽  
Fall Temperature

<p>The tree-ring densitometric studies conducted in the semiarid regions are rare, among them, minimum earlywood density (MND) records the strongest climate signals than other density parameters. In contrast, maximum density of latewood (MXD) in cold and humid regions usually shows the most significant association with summer temperatures. Density parameters of Purplecone Spruce (Picea purpurea Mast.) in Mt. Shouyang, northwestern China, a typical semiarid region were obtained to test the density-climate relationships. It is showed that MXD has strong positive correlations with temperatures and a negative correlation with precipitation in the late growing season from July to September. MND is significantly positively correlated with temperature and positively correlated with precipitation during the early growing season. During early growing season, spring droughts always occur due to low precipitation. A narrow ring is built under moisture stress, since tree growth is inhibited by decreasing cell division and cell enlargement. With the intensification of monsoon, more precipitation is available, which can basically meet the needs of tree growth. During strong monsoon season with humid conditions, trees are less affected by moisture stress. In this case, high temperature could increase cell wall thickness in the latewood which strongly affects the tree-ring maximum density. It could explain why there is a significant positive correlation between MXD and summer-fall temperature.</p>

scholarly journals Tree growth and its climate signal along latitudinal and altitudinal gradients: comparison of tree rings between Finland and Tibetan Plateau

2017 ◽  
Author(s):  
Lixin Lyu ◽  
Susanne Suvanto ◽  
Pekka Nöjd ◽  
Helena M. Henttonen ◽  
Harri Mäkinen ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Tree Ring ◽  
Tree Growth ◽  
Latitudinal Gradient ◽  
Ring Width ◽  
Growing Season ◽  
Climate Variables ◽  
Climate Data ◽  
Altitudinal Gradients ◽  
Summer Temperatures

Abstract. Latitudinal and altitudinal gradients can be utilized to forecast the impacts of climate changes on forests. To improve the understanding of forest dynamics on these gradients, we tested two hypotheses: (1) the change in the tree growth-climate relationship is similar along both latitudinal and altitudinal gradients, and (2) the time periods during which climate affects growth the most occur later towards higher latitudes and altitudes. We used tree-ring data from a latitudinal gradient in Finland and two altitudinal gradients on the Tibetan Plateau. We analysed the latitudinal and altitudinal growth patterns in tree-rings and investigated the growth-climate relationships of trees by correlating ring-width index chronologies with climate variables calculated with flexible time-windows, using daily-resolution climate data. The high latitude and altitude plots showed higher correlations between the tree-ring chronologies and growing season temperature. However, the effects of winter temperature showed differing patterns for the gradients. The timing of highest correlation with summer temperatures in southern sites was approximately one month ahead of the northern sites in the latitudinal gradient. In one out of the two altitudinal gradients the timing of strongest negative correlation with summer temperatures at low altitude sites was ahead of the treeline sites, possibly due to differences in moisture limitation. Mean values and the standard deviation of tree-ring width was found to increase with increasing mean summer temperatures on both types of gradients. Our results showed similarities of tree growth responses to growing season temperature between latitudinal and altitudinal gradients. However, differences in climate-growth relationships were also found between the gradients, due to differences in other factors, such as moisture conditions. Changes in the timing of the most critical climate variables demonstrated the need to use daily resolution climate data in studies on environmental gradients.

scholarly journals Different climate sensitivity for radial growth, but uniform for tree-ring stable isotopes along an aridity gradient in Polylepis tarapacana, the world’s highest elevation tree-species

2021 ◽  
Author(s):  
Milagros Rodriguez-Caton ◽  
Laia Andreu-Hayles ◽  
Mariano S Morales ◽  
Valérie Daux ◽  
Duncan A Christie ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Carbon Source ◽  
Tree Ring ◽  
Tree Growth ◽  
Carbon Sink ◽  
Growing Season ◽  
Wood Formation ◽  
Aridity Gradient ◽  
Leaf Level ◽  
Δ13c And Δ18o

Abstract Tree growth is generally considered to be temperature-limited at upper elevation treelines. Yet, climate factors controlling tree growth at semiarid treelines are poorly understood. We explored the influence of climate on stem growth and stable isotopes for Polyepis tarapacana, the world’s highest elevation tree-species found only in the South American Altiplano. We developed tree-ring width index (RWI), oxygen (δ18O) and carbon (δ13C) chronologies for the last 60 years at four P. tarapacana stands located above 4,400 meters in elevation, along a 500-km latitude-aridity gradient. Total annual precipitation decreased from 300 to 200 mm from the northern to the southern sites. We used RWI as a proxy of wood formation (carbon sink) and isotopic tree-ring signatures as proxies of leaf-level gas exchange processes (carbon source). We found distinct climatic conditions regulating carbon-sink processes along the gradient. Current-growing season temperature regulated RWI at wetter-northern sites, while prior-growing season precipitation determined RWI at arid-southern sites. This suggests that the relative importance of temperature to precipitation in regulating tree growth is driven by site-water availability. In contrast, warm and dry growing-seasons resulted in enriched tree-ring δ13C and δ18O at all study sites, suggesting that similar climate conditions control carbon-source processes. Site-level δ13C and δ18O chronologies were significantly and positively related at all sites, with the strongest relationships among the southern-drier stands. This indicates an overall regulation of intercellular carbon dioxide via stomatal conductance for the entire P. tarapacana network, with greater stomatal control when aridity increases. The manuscript also highlights a coupling and decoupling of physiological processes at leaf level versus wood formation depending on their respectively uniform and distinct sensitivity to climate. This study contributes to better understand and predict the response of high-elevation Polylepis woodlands to rapid climate changes and projected drying in the Altiplano.

scholarly journals A 406-year non-growing-season precipitation reconstruction in the southeastern Tibetan Plateau

2021 ◽  
Vol 17 (6) ◽  
pp. 2381-2392
Author(s):  
Maierdang Keyimu ◽  
Zongshan Li ◽  
Bojie Fu ◽  
Guohua Liu ◽  
Fanjiang Zeng ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Tree Ring ◽  
Tree Growth ◽  
Ring Width ◽  
Growing Season ◽  
Climatic Conditions ◽  
Forest Growth ◽  
Drought Severity ◽  
Precipitation Reconstruction ◽  
Southeastern Tibetan Plateau

Abstract. Trees record climatic conditions during their growth, and tree rings serve as proxy to reveal the features of the historical climate of a region. In this study, we collected tree-ring cores of hemlock forest (Tsuga forrestii) from the northwestern Yunnan area of the southeastern Tibetan Plateau (SETP) and created a residual tree-ring width (TRW) chronology. An analysis of the relationship between tree growth and climate revealed that precipitation during the non-growing season (NGS) (from November of the previous year to February of the current year) was the most important constraining factor on the radial tree growth of hemlock forests in this region. In addition, the influence of NGS precipitation on radial tree growth was relatively uniform over time (1956–2005). Accordingly, we reconstructed the NGS precipitation over the period spanning from 1600–2005. The reconstruction accounted for 28.5 % of the actual variance during the common period of 1956–2005. Based on the reconstruction, NGS was extremely dry during the years 1656, 1694, 1703, 1736, 1897, 1907, 1943, 1982 and 1999. In contrast, the NGS was extremely wet during the years 1627, 1638, 1654, 1832, 1834–1835 and 1992. Similar variations of the NGS precipitation reconstruction series and Palmer Drought Severity Index (PDSI) reconstructions of early growing season from surrounding regions indicated the reliability of the present reconstruction. A comparison of the reconstruction with Climate Research Unit (CRU) gridded data revealed that our reconstruction was representative of the NGS precipitation variability of a large region in the SETP. Our study provides the first historical NGS precipitation reconstruction in the SETP which enriches the understanding of the long-term climate variability of this region. The NGS precipitation showed slightly increasing trend during the last decade which might accelerate regional hemlock forest growth.

A 200-Year Perspective of Climate Variability and the Response of White Spruce in Interior Alaska

2003 ◽  
Author(s):  
Glenn Patrick Juday ◽  
Valerie Barber
Keyword(s):  
Nineteenth Century ◽  
North America ◽  
Climate Variability ◽  
Tree Ring ◽  
Tree Growth ◽  
White Spruce ◽  
Boreal Region ◽  
The North ◽  
Interior Alaska ◽  
Summer Temperatures

The two most important life functions that organisms carry out to persist in the environment are reproduction and growth. In this chapter we examine the role of climate and climate variability as controlling factors in the growth of one of the most important and productive of the North American boreal forest tree species, white spruce (Picea glauca [Moench] Voss). Because the relationship between climate and tree growth is so close, tree-ring properties have been used successfully for many years as a proxy to reconstruct past climates. Our recent reconstruction of nineteenth- century summer temperatures at Fairbanks based on white spruce tree-ring characteristics (Barber et al. in press) reveals a fundamental pattern of quasi-decadal climate variability. The values in this reconstruction of nineteenth-century Fairbanks summer temperatures are surprisingly warm compared to values in much of the published paleoclimatic literature for boreal North America. In this chapter we compare our temperature reconstructions with ring-width records in northern and south-central Alaska to see whether tree-growth signals in the nineteenth century in those regions are consistent with tree-ring characteristics in and near Bonanza Creek (BNZ) LTER (25 km southwest of Fairbanks) that suggest warm temperatures during the mid-nineteenth century. We also present a conceptual model of key limiting events in white spruce reproduction and compare it to a 39-year record of seed fall at BNZ. Finally, we derive a radial growth pattern index from white spruce at nine stands across Interior Alaska that matches recent major seed crop events in the BNZ monitoring period, and we identify dates after 1800 when major seed crops of white spruce, which are infrequent, may have been produced. The boreal region is characterized by a broad zone of forest with a continuous distribution across Eurasia and North America, amounting to about 17% of the earth’s land surface area (Bonan et al. 1992). The boreal region is often conceived of as a zone of relatively homogenous climate, but in fact a surprising diversity of climates are present. During the long days of summer, continental interior locations under persistent high-pressure systems experience hot weather that can promote extensive forest fires frequently exceeding 100 kilohectares (K ha). Summer daily maximum temperatures are cooled to a considerable degree in maritime portions of the boreal region affected by air masses that originate over the North Atlantic, North Pacific, or Arctic Oceans.

Intra-annual climatic signal in tree rings of Larix sp. based on the Vaganov-Shashkin model output

2021 ◽  
Author(s):  
Marina Fonti ◽  
Olga Churakova (Sidorova) ◽  
Ivan Tychkov
Keyword(s):  
Tree Ring ◽  
Tree Growth ◽  
Climatic Factors ◽  
Ring Width ◽  
Growing Season ◽  
Climatic Conditions ◽  
Limiting Factor ◽  
Precipitation Regime ◽  
The North ◽  
Temperature And Precipitation

<p>Air temperature increase and change in precipitation regime have a significant impact on northern forests leading to the ambiguous consequences due to the complex interaction between the ecosystem plant components and permafrost. One of the major interests in such circumstances is to understand how tree growth of the main forest species of the Siberian North will change under altering climatic conditions. In this work, we applied the process-based Vaganov-Shashkin model (VS - model) of tree growth in order to estimate the daily impact of climatic conditions on tree-ring width of larch trees in northeastern Yakutia (Larix cajanderi Mayr.) and eastern Taimyr (Larix gmelinii Rupr. (Rupr.) for the period 1956-2003, and to determine the extent to which the interaction of climatic factors (temperature and precipitation) is reflected in the tree-ring anatomical structure. Despite the location of the study sites in the harsh conditions of the north, and temperature as the main limiting factor, it was possible to identify a period during the growing season when tree growth was limited by lack of soil moisture. The application of the VS-model for the studied regions allowed establishing in which period of the growing season the water stress is most often manifest itself, and how phenological phases (beginning, cessation, and duration of larch growth) vary among the years.</p><p>The research was funded by RFBR, Krasnoyarsk Territory and Krasnoyarsk Regional Fund of Science, project number 20-44-240001 and by the Russian Ministry of Science and Higher Education (projects FSRZ-2020-0010).</p>

scholarly journals Tree growth and its climate signal along latitudinal and altitudinal gradients: comparison of tree rings between Finland and the Tibetan Plateau

2017 ◽  
Vol 14 (12) ◽  
pp. 3083-3095 ◽  
Author(s):  
Lixin Lyu ◽  
Susanne Suvanto ◽  
Pekka Nöjd ◽  
Helena M. Henttonen ◽  
Harri Mäkinen ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Tree Ring ◽  
Tree Growth ◽  
Latitudinal Gradient ◽  
Ring Width ◽  
Growing Season ◽  
The Tibetan Plateau ◽  
Climate Variables ◽  
Climate Data ◽  
Altitudinal Gradients

Abstract. Latitudinal and altitudinal gradients can be utilized to forecast the impact of climate change on forests. To improve the understanding of how these gradients impact forest dynamics, we tested two hypotheses: (1) the change of the tree growth–climate relationship is similar along both latitudinal and altitudinal gradients, and (2) the time periods during which climate affects growth the most occur later towards higher latitudes and altitudes. To address this, we utilized tree-ring data from a latitudinal gradient in Finland and from two altitudinal gradients on the Tibetan Plateau. We analysed the latitudinal and altitudinal growth patterns in tree rings and investigated the growth–climate relationship of trees by correlating ring-width index chronologies with climate variables, calculating with flexible time windows, and using daily-resolution climate data. High latitude and altitude plots showed higher correlations between tree-ring chronologies and growing season temperature. However, the effects of winter temperature showed contrasting patterns for the gradients. The timing of the highest correlation with temperatures during the growing season at southern sites was approximately 1 month ahead of that at northern sites in the latitudinal gradient. In one out of two altitudinal gradients, the timing for the strongest negative correlation with temperature at low-altitude sites was ahead of treeline sites during the growing season, possibly due to differences in moisture limitation. Mean values and the standard deviation of tree-ring width increased with increasing mean July temperatures on both types of gradients. Our results showed similarities of tree growth responses to increasing seasonal temperature between latitudinal and altitudinal gradients. However, differences in climate–growth relationships were also found between gradients due to differences in other factors such as moisture conditions. Changes in the timing of the most critical climate variables demonstrated the necessity for the use of daily-resolution climate data in environmental gradient studies.

scholarly journals Neue Ergebnisse zur Gletscher- und Klimageschichte des Spätmittelalters und der Neuzeit

1985 ◽  
Vol 40 (4) ◽  
pp. 168-185 ◽  
Author(s):  
H. Holzhauser
Keyword(s):  
Middle Ages ◽  
Tree Growth ◽  
Regional Climate ◽  
Maximum Density ◽  
Maximal Extension ◽  
Climatic Fluctuations ◽  
X Ray ◽  
Modern Times ◽  
Late Middle Ages ◽  
Summer Temperatures

Abstract. This article contributes to the glacier and climatic fluctuations during the late Middle Ages and the Modern Times. With the aid of radiocarbon dating of fossil woods and a fossil soil (fAh) located in the gletschervorfeld of two glaciers (Glacier de Zinal and Riedgletscher, Valais), the foUowing glacier advances could be shown: between 890 yBP and 1095 yBP, at 515 yBP, in the seventeenth and in the nineteenth Century. The tree rings from a larch (Larix decidua Mill.) near the glacier and the tree line (Riedgletscher, 2180 m altitude) was analysed by the X-ray densitometry. The maximum density of the annual rings reflects the summer temperatures since the middle of the twelfth Century. The fluctuations of the maximum density shows a close interrelation with the fluctuations of the Grosser Aletschgletscher (Valais). The local climatic influence of the Riedgletscher during maximal extension is visible in reduced tree-growth. During the retreat phase, when the glacier melted back, the regional climate dominates the tree-growth again.

Climate change and tree-ring relationships of Nothofagus menziesii tree-line forests

2001 ◽  
Vol 31 (11) ◽  
pp. 1981-1991 ◽  
Author(s):  
Louise E Cullen ◽  
Jonathan G Palmer ◽  
Richard P Duncan ◽  
Glenn H Stewart
Keyword(s):  
New Zealand ◽  
Tree Ring ◽  
Climate Warming ◽  
Tree Growth ◽  
Natural Disturbance ◽  
Tree Line ◽  
Climatic Control ◽  
Influence Of Temperature On ◽  
Summer Temperatures ◽  
The Impact

To assess the sensitivity of New Zealand tree lines to climate warming, we compared the tree-ring growth characteristics and temperature relationships of silver beech (Nothofagus menziesii (Hook. f.) Oerst) at two elevations, ca. 1200 m (tree line) and ca. 1100 m. Modelled relationships between climate series and tree rings indicated that the main climatic control on tree growth was current summer temperatures. Nevertheless, temperatures during earlier seasons can influence tree growth, pointing to a complex relationship between radial growth and climate at tree line. Overall, the similarity in the growth–temperature relationships for trees at both elevations indicated that high-altitude N. menziesii forests should be useful for examining the impact of climate warming on tree growth. However, the level of common growth variation was greater in the below tree line chronologies, suggesting that other factors, including natural disturbance, may affect or compete with the influence of temperature on tree-ring growth at tree line. Despite the importance of summer temperatures for tree growth at or near tree line and the reported increase in summer temperatures since 1950 in New Zealand, ring widths have not increased in recent decades. We conclude, therefore, that in these N. menziesii tree-line forests there has been no detectable tree-ring growth response to climate warming.

scholarly journals Comparison of the Radial Growth Response of Picea crassifolia to Climate Change in Different Regions of the Central and Eastern Qilian Mountains

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1015
Author(s):  
Xuan Wu ◽  
Liang Jiao ◽  
Dashi Du ◽  
Changliang Qi ◽  
Ruhong Xue
Keyword(s):  
Climate Change ◽  
Tree Growth ◽  
Central Region ◽  
Radial Growth ◽  
Growing Season ◽  
Qilian Mountains ◽  
Growth Patterns ◽  
Total Precipitation ◽  
Picea Crassifolia ◽  
The Qilian Mountains

It is important to explore the responses of radial tree growth in different regions to understand growth patterns and to enhance forest management and protection with climate change. We constructed tree ring width chronologies of Picea crassifolia from different regions of the Qilian Mountains of northwest China. We used Pearson correlation and moving correlation to analyze the main climate factors limiting radial growth of trees and the temporal stability of the growth–climate relationship, while spatial correlation is the result of further testing the first two terms in space. The conclusions were as follows: (1) Radial growth had different trends, showing an increasing followed by a decreasing trend in the central region, a continuously increasing trend in the eastern region, and a gradually decreasing trend in the isolated mountain. (2) Radial tree growth in the central region and isolated mountains was constrained by drought stress, and tree growth in the central region was significantly negatively correlated with growing season temperature. Isolated mountains showed a significant negative correlation with mean minimum of growing season and a significant positive correlation with total precipitation. (3) Temporal dynamic responses of radial growth in the central region to the temperatures and SPEI (the standardized precipitation evapotranspiration index) in the growing season were unstable, the isolated mountains to total precipitation was unstable, and that to SPEI was stable. The results of this study suggest that scientific management and maintenance plans of the forest ecosystem should be developed according to the response and growth patterns of the Qinghai spruce to climate change in different regions of the Qilian Mountains.

scholarly journals Analysis of Drought Characteristics in Xilingol Grassland of Northern China Based on SPEI and Its Impact on Vegetation

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Siqin Tong ◽  
Yuhai Bao ◽  
Rigele Te ◽  
Qiyun Ma ◽  
Si Ha ◽  
...  
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Pearson Correlation ◽  
Growing Season ◽  
Vegetation Coverage ◽  
Semiarid Region ◽  
Linear Regression Method ◽  
Upward Trend ◽  
Drought Effect ◽  
Positive Correlation

This research is based on the standardized precipitation evapotranspiration index (SPEI) and normalized difference vegetation index (NDVI) which represent the drought and vegetation condition on land. Take the linear regression method and Pearson correlation analysis to study the spatial and temporal evolution of SPEI and NDVI and the drought effect on vegetation. The results show that (1) during 1961–2015, SPEI values at different time scales showed a downward trend; SPEI-12 has a mutation in 1997 and the SPEI value significantly decreased after this year. (2) During 2000–2015, the annual growing season SPEI has an obvious upward trend in time and the apparent wetting spatially. (3) In the recent 16 years, the growing season NDVI showed an upward trend and more than 80% of the total area’s vegetation increased in Xilingol. (4) Vegetation coverage in Xilingol grew better in humid years and opposite in arid years. SPEI and NDVI had a significant positive correlation; 98% of the region showed positive correlation, indicating that meteorological drought affects vegetation growth more in arid and semiarid region. (5) The effect of drought on vegetation has lag effect, and the responses of different grassland types to different scales of drought were different.

Sign in / Sign up

Export Citation Format

Share Document