Page 220 - 《高原气象》2025年第5期

高 原 气 象 44 卷
1338

The Impact of Hydrothermal Factors on the Water Conservation

Function of Qinghai Spruce in the Qilian Mountains

CHE Zongxi， SUN Guoping， WANG Ling， PEI Yuazheng， ZHU Tong， ZENG Wenfang
（Gansu Qilian Mountains National Nature Reserve Authority / Observation and Research Station of Subalpine
Ecology Systems in the middle Qilian Mountains， Zhangye 734000， Gansu， China）

Abstract： The investigation of the impact of hydrothermal variation on the water conservation function of forests
holds substantial scientific importance for formulating rational ecological protection policies and water resource
management strategies. The present study focuses on the hydrothermal variation of Picea crassifolia forests in
Qinghai province， aiming to elucidate how different hydrothermal conditions influence the water conservation ca‐
pacity of these forests. Long-term hydrothermal data spanning over 21 years were analyzed using regression fit‐
ting models and water balance models. The findings can be summarized as follows： （1） The average water con‐
tent of moss and soil at various elevations （2600， 2700， 2900， 3100， and 3300 meters） was examined. The re‐
sults showed that the average water content of moss and soil at these elevations was 100. 76%， 27. 42%，
86. 94%， and 33. 18%， respectively. Regression analysis revealed that the trends in water content followed qua‐
dratic and exponential functions. Moss exhibited significant long-term water absorption， retention， and storage
capacities， indicating a robust water conservation function. These results highlight the crucial role of moss in
maintaining the water conservation capacity of the forest ecosystem.（2） The study analyzed the relationship be‐
tween soil temperature and elevation. Soil temperature decreased with increasing elevation at a rate of 0. 39% per
100 meters， with a significantly linear decline. The elevation of 2900 meters emerged as a critical threshold：
above this point， soil temperature remained below 0 ℃， while below 2900 meters， soil temperature was above
0 ℃. Additionally， air temperature exhibited a fluctuating pattern with increasing elevation， following a signifi‐
cant quadratic polynomial trend. These findings underscore the influence of elevation on thermal conditions，
which in turn affect the hydrological processes in the forest ecosystem.（3） The mean water conservation capaci‐
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ty of the study area was calculated to be 159. 63 mm·m ·a ， with a significant quadratic trend within the 2600~
3300 m elevation range. Correlation analysis showed that precipitation and soil moisture were significantly posi‐
tively correlated with water conservation capacity （R =0. 994 and 0. 988， P<0. 01， respectively）， while soil tem‐
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perature and forest evapotranspiration were significantly negatively correlated with water conservation capacity
（R =0. 96 and 0. 98， P<0. 01， respectively）. These results indicate that precipitation and soil moisture promote
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water conservation， while temperature and evapotranspiration from the forest floor inhibit it. Therefore， precipi‐
tation and temperature are key determinants of vegetation growth and water conservation function in the Picea
crassifolia forests of Qinghai province. The findings emphasize the importance of considering elevation， tempera‐
ture， and precipitation in formulating effective ecological protection policies and water resource management
strategies for these forest ecosystems.
Key words： hydrothermal conditions； water conservation function； Picea crassifolia forest； Qilian Mountains