KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 新疆荒漠地区植物叶和粗根的碳氮磷化学计量特征及其与环境的关系 | |
| Alternative Title | Carbon Nitrongen and Phosphorus Stoichiometries of Plant Leaves and Coarse Roots and Their Relations with Environment Factors across the Deserts in Xinjiang, China |
| 何茂松 | |
| Subtype | 硕士 |
| Thesis Advisor | 韩文轩 ; 李凯辉 |
| 2019-06-30 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 理学硕士 |
| Keyword | 环境因子 植物功能型 碳氮磷异速关系 根叶间化学异速关系 生态化学计量 Environmental factors Plant functional types Allometry of carbon and nitrogen against phosphorus Nutrient allometry of leaf vs root Ecological stoichiometry |
| Abstract | 荒漠生态系统具有独特的气候和化学计量特征。本研究在生长季节系统采集新疆荒漠地区 89 个地点的优势种植物的叶和粗根。通过测定植物叶和粗根中的碳（C）、氮（N）、磷（P）含量，研究以下三个内容：（1）叶碳氮磷化学计量特征及其与气候因子的关系；（2）粗根碳氮磷化学计量特征及其与环境因子的关系；（3）叶与粗根碳氮磷化学计量特征的关系及其与环境因子的关系。结果表明：荒漠植物的叶 C、 N 和 P 的平均含量为 394 mg g-1、 18.4 mg g-1和 1.14 mg g-1， C:N、 C:P 和 N:P 平均为 28、 419 和 18；荒漠植物的叶 C、 N 和P 含量低于中国木本植物，易受 P 限制。灌木比乔木和草本植物的 N 含量高，灌木 P 含量比草本（乔木）低（高）； C3 比 C4 植物叶的 C、 N、 C:P、 N:P 高。随年均降水量增加，叶 C、 N、 P 化学计量特征呈非线性变化。随年均温升高，叶 N、P 含量降低， C:P 和 N:P 升高。年均降水量大于年均温度和植物功能类型差异对叶片化学计量特征的影响。荒漠植物粗根 C、 N 和 P 含量为 440 mg g-1、 9.9 mg g-1 和 0.82 mg g-1， C:N、C:P 和 N:P 为 51、 707 和 15。 新疆荒漠植物粗根 C、 N、 P 含量显著高于中国木本植物对应器官的养分含量。 不同生活型植物的粗根 C 含量存在显著差异，其中乔木最高、灌木次之、草本植物最低，而粗根 P 含量表现为相反的趋势；此外，灌木的粗根 N 含量显著高于乔木和草本植物。粗根中 P 与 C、 N 呈异速生长关系，且 P 比 C、 N 变化得更快（C~P-0.460 和 N~P0.699）。 粗根 C、 N、 P 化学计量特征与经纬度、年平均温度、年平均降水量存在非线性关系。荒漠植物粗根 C、 N、P 计量特征主要受气候因子（年平均降水量）的影响，生活型差异和土壤养分影响次之，反映了荒漠植物生长主要受水分限制。叶与粗根中对应元素或比值的异速关系幂指数分别为 0.88（N）、 0.46（P）和 0.60（N:P）。乔木叶与粗根对应元素或比值的异速关系幂指数分别为 0.42（N）、0.37（P）和 0.39（N:P），均低于灌木（1.05（N）、 0.51（P）和 0.79（N:P））或草本植物（1.18（N）、 -0.56（P）和 0.55（N:P））的叶与粗根中对应元素或比值的异速关系幂指数的绝对值。 C4 植物叶与粗根中对应元素或比值的异速关系幂指数分别为 0.97（N）、 0.63（P） 和 0.75（N:P），分别高于 C3 植物中相应的幂指数值（0.82（N）、 0.37（P）和 0.55（N:P））。随着干旱程度的增加（干旱指数的减小），叶和粗根中的 N、 P、 N:P 降低，而叶与粗根对应的元素或比值之间的差异性增加。随着土壤 N、 P、 N:P 增加，叶和粗根的 N、 P、 N:P 增加、且叶与粗根 N:P 间的差异性增加。随着土壤 pH 增大，叶和粗根的 N、 N:P 增加、且叶与粗根 P 之间的差异性降低而 N 或 N:P 间的差异性增加。 综合分析各生物和非生物因子对叶与粗根之间对应元素或比值的关系的影响程度，结果表明植物功能型差异>土壤理化性质>干旱程度。总之，荒漠植物叶和粗根的 C、 N、 P 计量特征主要受气候因子的影响，生活型差异和土壤养分影响次之，反映了荒漠植物生长主要受水分限制。 叶与粗根N、 P、 N:P 呈异速生长关系（N 叶~N 根 0.88， P 叶~P 根 0.46， (N:P)叶~(N:P)根 0.6），粗根比叶中对应元素含量或比值的变化更快，表明前者的氮磷化学计量对环境因子变化更敏感。本研究结果可为干旱区生物地球化学建模提供参考和基础数据，并为干旱区生态系统的保护提供理论基础。 |
| Other Abstract | Desert ecosystems have unique climate and ecological stoichiometry. Wecollected leaves and coarse roots of the dominant plant species during the growingseason in 89 desert locations in Xinjiang, China. Plant carbon (C), nitrogen (N), andphosphorus (P) concentrations were measured to explore (1) the variations in leaf C,N and P stoichiometry and their relationships to climatic factors; (2) the variations incoarse-root C, N and P stoichiometry and their relationships to environmental factors;and (3) the corresponding nutrient allometries between leaves and coarse roots andtheir relations with environmental factors.The results showed that the average concentrations of leaf C, N, and P in thesedesert plants were 394 mg g-1, 18.4 mg g-1, and 1.14 mg g-1, respectively; and the C:N,C:P, and N:P were averagely 28, 419, and 18, respectively. These desert plants ofXinjiang showed lower foliar nutrients than the common Chinese woody plants, andmight tend to be more limited by P than N given their relative higher N:P. Shrubs hadhigher N concentration than did trees and herbs, and lower (higher) P concentrationthan herbs (trees) did. The leaf C, N, C:P, and N:P were higher in C3 plants than in C4plants. The stoichiometry of leaves C, N and P showed nonlinear relationships withmean annual precipitation (MAP). With increasing mean annual temperature (MAT),leaf N and P decreased while leaf C:P and N:P increased. MAP showed greater controlon the stoichiometry of leaf C, N and P than MAT and plant functional type.The coarse-root C, N, and P concentration of these desert plants were averagely440 mg g-1, 9.9 mg g-1, and 0.82 mg g-1, respectively, and the mean C:N, C:P, and N:Pwere 51, 707, and 15, respectively. The average coarse-root C, N, and Pconcentrations were higher in Xinjiang’s desert plants than those in Chinese woodyplants as a whole.Among the three growth-forms, coarse-root C concentration was highest in treesbut lowest in herbaceous plants, while coarse-root P was highest in herbs but lowest intrees; and the coarse-root N concentration was higher in shrubs, compared to trees andherbs. Coarse-root C and N showed allometric relationships against P (C~P-0.460andN~P0.699), suggesting that P changes faster than C and N in the coarse roots.The nonlinear relationships existed between coarse-root nutrients and longitude,latitude, MAT, and MAP. In comparison with plant type and soil nutrient concentration, the climatic factors (especially MAP) had greater influence on thestoichiometry of C, N and P in coarse roots of the desert plants, reflecting the waterconstraints in the desert ecosystems.The allometric scaling exponents of N, P, or N:P ratio of leaves against the coarseroots were 0.88 (N), 0.46 (P), and 0.60 (N:P), respectively. The scaling exponents fornutrients or their ratio in leaves vs roots of trees were 0.42 (N), 0.37 (P), and 0.39(N:P), respectively, lower than the exponential absolute values of shrubs (1.05 (N),0.51 (P), and 0.79 (N:P)) and herbs (1.189 (N), -0.56 (P), and 0.55 (N:P)). Thecorresponding exponents of C4 plants were 0.97 (N), 0.63 (P), and 0.75 (N:P),respectively, higher than those of C3 plants (0.82 (N), 0.37 (P), and 0.55 (N:P)).Both leaf and coarse-root N, P, and N:P decreased, while the ratios of leaf tocoarse-root N, P, or N:P increased, with decreasing aridity index (i.e., more severearidity). As the soil N, P, or N:P increased, both leaf and coarse-root N, P, and N:Pincreased, and the ratio of leaf to coarse-root N:P also increased. Both leaf andcoarse-root N and N:P, as well as the ratio of leaf to coarse-root P, decreased withincreasing soil pH; whereas the ratio of leaf to coarse-root N or N:P increased withhigher soil pH. Generally speaking, plant functional type showed more powerfuleffect on the ratios of leaf to coarse-root N, P, or N:P, compared with soil physical andchemical properties and aridity.In conclusion, the C, N, and P stoichiometry of leaves and coarse roots of desertplants were mainly affected by climatic factors, as well as by plant functional type andsoil nutrient contents, suggesting that the growth of desert plants be primarilyrestricted by water availability. The N, P, or N:P of leaves vs coarse roots showedallometric relationships (Nleaf~Nroot0.88, Pleaf~Proot0.46, or (N:P)leaf~(N:P)root0.6),suggesting that the N, P, or N:P in coarse roots changed more rapidly than did those inplant leaves, or that the coarse-root N and P stoichiometry might be more sensitive toenvironmental changes. The results of this study can provide reference and basic datafor biogeochemical modeling, and also a theoretical basis for the protection of aridecosystems in Xinjiang. |
| Subject Area | 生态学 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/15324 |
| Collection | 中国科学院新疆生态与地理研究所 研究系统 |
| Affiliation | 中国科学院新疆生态与地理研究所 |
| First Author Affilication | 中国科学院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 何茂松. 新疆荒漠地区植物叶和粗根的碳氮磷化学计量特征及其与环境的关系[D]. 北京. 中国科学院大学,2019. |
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