scholarly journals Relationships between Tree Age and Climate Sensitivity of Radial Growth in Different Drought Conditions of Qilian Mountains, Northwestern China

Forests ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 135 ◽  
Author(s):  
Lingnan Zhang ◽  
Yuan Jiang ◽  
Shoudong Zhao ◽  
Liang Jiao ◽  
Yan Wen
Keyword(s):  
Climate Sensitivity ◽  
Radial Growth ◽  
Qilian Mountains ◽  
Northwestern China ◽  
Tree Age ◽  
Drought Conditions

Response to climate changes in radial growth of Picea crassifolia in the Qilian mountains of northwestern China

2013 ◽  
Vol 15 (4) ◽  
pp. 310-319 ◽  
Author(s):  
Jin-Mei Xu ◽  
Fu-Cheng Bao ◽  
Jian-Xiong Lv ◽  
Rong-Feng Huang ◽  
You-Ke Zhao ◽  
...  
Keyword(s):  
Radial Growth ◽  
Climate Changes ◽  
Qilian Mountains ◽  
Northwestern China ◽  
Picea Crassifolia ◽  
The Qilian Mountains

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.

An 850-year tree-ring-based reconstruction of drought history in the western Qilian Mountains of northwestern China

2014 ◽  
Vol 35 (11) ◽  
pp. 3308-3319 ◽  
Author(s):  
Xiaohua Gou ◽  
Linlin Gao ◽  
Yang Deng ◽  
Fahu Chen ◽  
Meixue Yang ◽  
...  
Keyword(s):  
Tree Ring ◽  
Qilian Mountains ◽  
Northwestern China

scholarly journals High diversity of nitrogen-fixing bacteria in the upper reaches of the Heihe River, northwestern China

2013 ◽  
Vol 10 (8) ◽  
pp. 5589-5600 ◽  
Author(s):  
X. S. Tai ◽  
W. L. Mao ◽  
G. X. Liu ◽  
T. Chen ◽  
W. Zhang ◽  
...  
Keyword(s):  
Water Conservation ◽  
Bacterial Communities ◽  
Nifh Gene ◽  
Qilian Mountains ◽  
Northwestern China ◽  
Heihe River ◽  
Meadow Soil ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
Gene Copies

Abstract. Vegetation plays a key role in water conservation in the southern Qilian Mountains (northwestern China), located in the upper reaches of the Heihe River. Nitrogen-fixing bacteria are crucial for the protection of the nitrogen supply for vegetation in the region. In the present study, nifH gene clone libraries were established to determine differences between the nitrogen-fixing bacterial communities of the Potentilla parvifolia shrubland and the Carex alrofusca meadow in the southern Qilian Mountains. All of the identified nitrogen-fixing bacterial clones belonged to the Proteobacteria. At the genus level, Azospirillum was only detected in the shrubland soil, while Thiocapsa, Derxia, Ectothiorhodospira, Mesorhizobium, Klebsiella, Ensifer, Methylocella and Pseudomonas were only detected in the meadow soil. The phylogenetic tree was divided into five lineages: lineages I, II and III mainly contained nifH sequences obtained from the meadow soils, while lineage IV was mainly composed of nifH sequences obtained from the shrubland soils. The Shannon–Wiener index of the nifH genes ranged from 1.5 to 2.8 and was higher in the meadow soils than in the shrubland soils. Based on these analyses of diversity and phylogeny, the plant species were hypothesised to influence N cycling by enhancing the fitness of certain nitrogen-fixing taxa. The number of nifH gene copies and colony-forming units (CFUs) of the cultured nitrogen-fixing bacteria were lower in the meadow soils than in the shrubland soils, ranging from 0.4 × 107 to 6.9 × 107 copies g−1 soil and 0.97 × 106 to 12.78 × 106 g−1 soil, respectively. Redundancy analysis (RDA) revealed that the diversity and number of the nifH gene copies were primarily correlated with aboveground biomass in the shrubland soil. In the meadow soil, nifH gene diversity was most affected by altitude, while copy number was most impacted by soil-available K. These results suggest that the nitrogen-fixing bacterial communities beneath Potentilla were different from those beneath Carex.

scholarly journals Growth and yield estimation of Chamaecyparis spp. through tree ring analysis

2013 ◽  
Vol 22 (2) ◽  
pp. 36-42 ◽  
Author(s):  
D. K. Kharal ◽  
T. Fujiwara
Keyword(s):  
Tree Ring ◽  
Radial Growth ◽  
Ring Width ◽  
Forest Products ◽  
Growth And Yield ◽  
Tree Age ◽  
Biomass Estimation ◽  
Tree Ring Analysis ◽  
Ring Density ◽  
Ring Analysis

Tree ring analysis is one of the most useful methods in volume and biomass estimation especially of the conifer trees. Ring width and ring density are important parameters in dendrochronological research. The present research was carried out with the aim of estimating the radial and volumetric growth of the Japanese Cypress trees (Chamaecyperis obstusa and C. pisifera). Destructive method was used while collecting the wood samples from the selected trees. Ring width and ring density were measured using soft X-ray densitometry method using micro-densitometer. Computer programme, developed by the Forestry and Forest Products Research Institute, Japan was used to analyze the ring with and ring density data. The average ring width of the Chamaecyparis spp. was found to be about 3.4 mm at the age of 30 years. However, two types of growth pattern were observed in the trees. Average radial growth was about 5% every year during the first 20 years of the tree age, whereas, the average radial growth was negative during the age of 20–30 years. Average density of the tree rings were increased by about 11% in each height of the trees starting from the ground. Similarly, the stem density decreased by about 3.4% annually along the radial direction from the pith.DOI: http://dx.doi.org/10.3126/banko.v22i2.9197Banko Janakari: A Journal of Forestry Information for NepalVol. 22, No. 2, 2012 November Page: 36-42 Uploaded date: 12/1/2013 

scholarly journals Regional and Local Moisture Gradients Drive the Resistance to and Recovery from Drought of Picea crassifolia Kom. in the Qilian Mountains, Northwest China

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 817 ◽  
Author(s):  
Lingnan Zhang ◽  
Hui Li ◽  
Yilin Ran ◽  
Keyi Wang ◽  
Xiaomin Zeng ◽  
...  
Keyword(s):  
Radial Growth ◽  
Northwest China ◽  
Qilian Mountains ◽  
Mean Annual Temperature ◽  
Western Region ◽  
Drought Event ◽  
Eastern Region ◽  
Picea Crassifolia ◽  
The Western Region ◽  
The Qilian Mountains

Increasing evidence suggests that extreme droughts cause more frequent tree growth reduction. To understand the consequences of these droughts better, this study used tree-ring cores from nine sites to investigate how moisture and altitudinal gradients affect the radial growth of Picea crassifolia Kom., a common species in the Qilian Mountains in northwest China. The total annual precipitation and mean annual temperature in the eastern region were higher than those in the western region of the Qilian Mountains. The trees in the eastern region showed stronger resistance to drought than those in the west, as they had a smaller difference in radial growth between drought disturbance and pre-drought disturbance. At the same time, the trees in the east showed weaker ability to recover from drought, as they had a subtle difference in radial growth between post-drought disturbance and drought disturbance. Furthermore, the trees in the east also showed weaker relative resilience to drought, as they had a small difference in radial growth between post-drought and drought disturbance weighted by growth in pre-drought disturbance. For trees below 3000 m a.s.l., trees with high resistance capacity usually had low recovery capacity and low relative resilience capacity. Trees at higher altitudes also showed stronger resistance to drought and weaker ability to recover from drought after a drought event than those at lower altitudes in the middle of the Qilian Mountains. Trees at lower altitudes in the middle of the Qilian Mountains had more difficulties recovering from more severe and longer drought events. In the context of global warming, trees in the western region and at lower altitudes should be given special attention and protection in forest management to enhance their resistance to extreme droughts.

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