NWIPB OpenIR
不同海拔梯度高寒草甸土壤、植物碳氮变化特征及对模拟气候变化的响应
其他题名Response of Simulated Climate Change on the Changes of Soil and Plant Carbon and Nitrogen with Different Altitude in Alpine Meadow
薛晓娟
学位类型硕士
导师李英年
2009-06-03
学位授予单位中国科学院西北高原生物研究所
学位授予地点西北高原生物研究所
关键词祁连山 气候变化 海拔 移地实验 土壤碳氮 植物碳氮 碳氮比
摘要本研究以中国科学院海北高寒草甸生态系统定位站(海北站)附近的祁连山冷龙岭南麓坡地山体垂直带(3200~4300m)为研究平台。以不同海拔高度为梯度,调查了自然垂直带气候、植被及土壤碳氮分布规律,并对不同海拔高度植被进行双向移栽,调查移栽后植被、土壤碳氮分布变化特征,重点研究了主要植物种和土壤碳、氮组分对海拔高度变化的响应。结果表明: 1. 祁连山冷龙岭南麓坡地气温随海拔的升高降低明显,年平均气温垂直递减率0.51℃•100m-1,不同季节直减率有所不同。日平均气温稳定≥0℃、≥3℃和≥5℃的积温直减率几乎相同,为92℃•100m-1,持续天数直减率9d•100m-1。土壤表层温度随海拔高度变化具有与气温相近的变化趋势。 2.不同海拔地上生物量具有明显的季节变化,在生长季呈典型的单峰型,表现为自日平均气温稳定≥0℃开始萌动发芽,生物量积累,至8月底9月初达到最大,且随海拔高度升高最大值出现时间滞后;地下生物量季节变化表现为锯齿型,各海拔地下生物量在生长季节内(5~9月)分别出现有两次明显的增值过程和减值过程。地下生物量垂直空间分布为倒金字塔型,表层(0~10cm)集中了地下生物量的80%以上。地上净初级生物量、地下生产力与海拔均有显著地负相关关系,相关系数分别为0.9366与0.9892。 3. 土壤有机质和全氮含量沿海拔高度从3200m开始下降至3400m后开始急剧上升,在3600米处最高,然后又迅速下降;土壤有机质和全氮在土壤垂直剖面分布趋势一致,表层土壤有机质和全氮含量高,随深度加深而降低。土壤碳氮比沿海拔高度的升高先增加后减小,但随海拔高度不同而有所差异。 4. 虽然植被移地仅为1年,但植物群落碳有一定的变化,除移地后各海拔高度中与3600m处的差异不显著外,其他3个海拔移往各海拔的植物群落碳差异显著,并且均表现出移地到3600m海拔的显著低于3200m处。植物群落氮与碳/氮虽然随海拔高度有一定的变化,但从差异性分析来看,只有从3800m处的植被移地后与各海拔间有显著性差异,其他3个高度的植被类型移地后所发生的差异不显著。 5. 移地后各海拔的典型植物叶片碳、氮和碳/氮表明:A)从3200m处移往各海拔高度的4种植物(麻花艽、美丽风毛菊、垂穗披碱草和鹅绒委陵菜)叶片碳素含量除麻花艽在各海拔高度间差异显著外,其他3种植物叶片碳在各海拔间差异不显著;麻花艽与美丽风毛菊的叶片氮素、碳/氮在各海拔间差异显著,其他2种植物在各海拔间差异不显著。B)从3400m移往各海拔的5种植物(兰石草、珠芽蓼、垂穗披碱草、金露梅和鹅绒委陵菜)叶片碳素含量除兰石草在各海拔高度间差异不显著外,其他4种植物叶片碳素在各海拔间差异显著;兰石草与鹅绒委陵菜的叶片氮素、碳/氮在各海拔间无显著差异,其他2种在各海拔间差异显著。C)从3600m处移往各海拔的3种植物(矮嵩草、雪白委陵菜和齿状风毛菊)叶片碳、氮与碳/氮均没有显著差异。D) 从3800m处移往各海拔的2种植物(矮嵩草,矮火绒草)中矮嵩草的叶片碳无显著差异外,其他都差异显著。
其他摘要The study was conducted in vertical distribution zone (3200~4300m) along the southern slope of Lenglongling on the Qilian Mountains near by the Haibei Alpine Meadow Ecosystem Research Station (HaibeiStation). By the microclimate auto observation systems, the air and soil temperature were recorded at 30 minutes intervals in six equidistant plots from 3200m to 4200m and the one plot at top mountains along with elevation gradients. Based on the investigation of the climate factors, vegetation and soil carbon and nitrogen (C/N), as well as the latter responded to transplantation reciprocally among 3200m, 3400m, 3600m and 3800m, and especially that the response of dominant plant species, and soil C/N on the altitude gradients were studied in the thesis. The results were as follows: 1. It was obvious that air and soil temperature decreased along with the ascension of altitude. The decline rate of annual mean air temperature was 0.51℃•100m-1, and varied by the different seasons. The accumulative temperature for ≥0℃、≥3℃and ≥5℃ had almost the same decline rate and was 92℃•100m-1.The decline rate of their lasting days was 9d•100m-1. The soil surface temperature and air temperature had the similar trend with the elevation ascending. According to vegetation types and climate characteristics, we divided the vegetation of our vertical studying zones into sub-alpine meadow, sub-alpine shrub meadow, alpine meadow,alpine sub-snow ice sparse vegetation. 2. The seasonal dynamics of the aboveground biomass was single apex in different altitudes, and it started to burgeon when the accumulative temperature was ≥0℃ in our research plots. The biomass reached its maximum in late August or early September, and whose maximum was lagged along the altitude climbing. The underground biomass in different altitudes showed sawtooth-type, and had two increasing and decreasing stages in growing season. Its dimensional distribution was inverted pyramid , and the underground biomass at the depth of 0~10cm accounted for above 80% of the total underground biomass. Aboveground and underground net primary production were significantly negatively related to the altitude(R=0.9366, R=0.9892). 3. SOM and total nitrogen both descended from 3200m to 3400m and then increased sharply. Subsequently, they reached their maximum at the site of 3600 m and then descended rapidly. The vertical distribution of SOM and total nitrogen had the similar trends on the soil profile. The contents in the surface layer were higher than that in deep layers, and it declined with soil depth increasing. The soil C/N was between 6 and 14 and was lower comparatively, which suggested that it was good for soil humus and organic nitrogen mineralization. The soil C/N increased first then declined with the increase of elevation. And its vertical distribution in the soil profile varied by elevations. 4. Although vegetation was transplanted only one year, the content of vegetation carbon had changed evidently. They were shown significant difference in different altitudes expect in the plots transplanted from 3600m, and it showed that the plots transplanted to 3200m were significantly higher than those to 3600m. The content of vegetation nitrogen and C/N had little changed. And Variance analysis showed that they were not significant different in other altitudes except 3800m. 5. The response of the leaf carbon, nitrogen and C/N from some special plant species to reciprocal transplantation was researched. The result showed that: A) Four plant species (G. straminea Maxim, S. superba Anthony, Elymus nutans and Potentilla anserina) were transplanted to different altitudes from 3200m and their contents of leaf carbon were not significantly different except G. straminea Maxim. Moreover, the content of leaf nitrgen and leaf C/N were not significant difference except G.straminea Maxim and S. superba Anthony. B) Five plant species (Lancea tibetica, Polygonum viviparum, Elymus nutans, Potentilla fruticosa and Potentilla anserina) were transplanted to differernt altitudes from 3400m and the content of leaf carbon were significant difference except Lancea tibetica. And the content of leaf nitrgen and leaf C/N were significant difference except L. tibetica and P. anserina. C) Three plant species (Kobresia. humilis, Potentilla nivea and S. katochaete Maxim) were transplanted to differernt altitudes from 3600m and the content of leaf carbon and nitegen and leaf C/N were not significant difference. D) Two plant species (K. Humilis and Leontopodium nanum) were transplanted to different altitudes and the leaf carbon and nitrgen and leaf C/N were significant difference except the leaf carbon of K. Humilis.
页数72
语种中文
文献类型学位论文
条目标识符http://210.75.249.4/handle/363003/3254
专题中国科学院西北高原生物研究所
推荐引用方式
GB/T 7714
薛晓娟. 不同海拔梯度高寒草甸土壤、植物碳氮变化特征及对模拟气候变化的响应[D]. 西北高原生物研究所. 中国科学院西北高原生物研究所,2009.
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