| 摘要: |
| 【目的】探究青海祁连圆柏林乔木层碳密度空间分异特征，为青海祁连圆柏林的科学经营和碳库管理提供理论依据。【方法】在青海祁连圆柏6个不同的分布区域（德令哈柏树园、都兰热水乡、祁连八宝镇、乌兰哈里哈图国家森林公园、兴海中铁林场、泽库麦秀林场）和不同立地条件（海拔、坡向、坡位和坡度）设置标准样地96个，每块标准地选取1～3株标准木，对每株标准木的干、枝、叶和根称重，测定各器官生物量和含碳量，进而估算乔木层生物量和碳密度，通过统计分析探讨祁连圆柏林乔木层碳密度在不同立地条件下的差异特征和主要影响因素。【结果】（1）6个区域祁连圆柏林乔木层碳密度差异较大，大小依次为兴海中铁林场（134.88 t/hm2）＞都兰热水乡（79.59 t/hm2）＞乌兰哈里哈图国家森林公园（71.96 t/hm2）＞德令哈柏树园（66.60 t/hm2）＞泽库麦秀林场（54.24 t/hm2）＞祁连八宝镇（52.39 t/hm2），其中兴海中铁林场与其他区域间均存在极显著差异(P＜0.01)。（2）祁连圆柏各器官碳密度的分配比例不同，不同器官依次表现为树干（38.37%）＞树枝（28.51%）＞树根(27.10%)＞树叶（6.02%）。（3）乔木层碳密度随海拔升高呈先升高后降低的趋势，其中以海拔＞3 500～≤3 700 m区域最大，为109.76 t/hm2；海拔＞2 900～≤3 100 m区域最小，为44.37 t/hm2。（4）阳坡的乔木层碳密度（86.55 t/hm2）高于阴坡（68.74 t/hm2），且差异显著(P＜0.05)。（5）乔木层碳密度随坡度增大呈先增大后减小的趋势，以坡度＞15°～≤25°最大（108.36 t/hm2）。（6）坡位不同，乔木层碳密度存在差异，其大小顺序为：下坡位（98.80 t/hm2）＞中坡位（75.72 t/hm2）＞上坡位（54.92 t/hm2）。【结论】青海祁连圆柏林乔木层碳密度在不同区域及不同立地条件下存在一定差异，海拔是处于主导地位的地形影响因子。 |
| 关键词: 祁连圆柏 乔木层碳密度 空间分异特征 立地条件 |
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| 基金项目:旱区生态水文与灾害防治国家林业局重点实验室2019年度科研项目“青海柏树生态系统有机碳空间分异特征研究” |
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| Spatial variation characterization of arbor layer carbon density in Juniperus przewalskii forest in Qinghai |
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QIANG Langlang,CHEN Zhilin,DANG Kunliang,et al
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| Abstract: |
| 【Objective】This study explored spatial variation characteristics of carbon density of Juniperus przewalskii forest to provide basis for scientific management and carbon pool management of J. przewalskii in Qinghai.【Method】The research set up 96 standard sites in six J. przewalskii forest distribution regions in Qinghai (Cypress Garden of Delingha City,Reshui Town of Dulan County,Babao Town of Qilian County,National Forest Park of Wulan County,Zhongtie Forest Centre of Xinghai County and Maixiu Forest Centre of Zeku County) with different site factors (elevation,slope aspect,slope position and slope).One to three standard trees were chosen for each standard plot to weigh and sample trunk,branches,leaves and roots of each standard tree,determine biomass and carbon content of each organ,and estimate arbor layer biomass and carbon density.Then statistics analysis was employed to discuss difference characteristics and main influencing factors of Juniperus przewalskii arbor layer carbon density under different site conditions.【Result】（1） In the six research plots of J. przewalskii forest,arbor layer carbon density had quite difference in the decreasing order of Zhongtie Forest Centre of Xinghai County（134.88 t/hm2）＞Reshui Town of Dulan County（79.59 t/hm2）＞National Forest Park of Wulan County（71.96 t/hm2）＞ Cypress Garden of Delingha City（66.60 t/hm2）＞Maixiu Forest Centre of Zeku County（54.24 t/hm2）＞Babao Town of Qilian County（52.39 t/hm2）.Among them,there were significant differences between Zhongtie Forest Centre of Xinghai County and other regions (P＜0.01).（2）Different organs had different carbon density ratios in the decreasing order of trunk（38.37%）＞branch（28.51%）＞root(27.10%)＞ leaf（6.02%）.（3）The arbor layer carbon density firstly increased and then decreased with increasing altitude gradient.The carbon density at ＞3 500-≤3 700 m above sea level (109.76 t/hm2) was the largest,while the carbon density at the ＞2 900-≤3 100 m above sea level (44.37 t/hm2) was the smallest.（4） The arbor layer carbon density (86.55 t/hm2) on sunny slope was significantly (P＜0.05) higher than on shady slope (68.74 t/hm2) (P＜0.05).（5） The arbor layer carbon density firstly increased and then decreased with increasing slope. The carbon density (108.36 t/hm2) was the highest at ＞15°-≤25° above slope level.（6）The arbor layer carbon densities were different at different slopes with the decreasing order of down slope（98.80 t/hm2）＞middle slope（75.72 t/hm2）＞up slope(54.92 t/hm2).【Conclusion】The arbor layer carbon density had differences among different regions and topographic factors.Elevation was the dominant topographic factor for arbor layer carbon density of J. przewalskii forest. |
| Key words: Juniperus przewalskii arbor layer carbon density spatial variation characterization topographic factor |
