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1.
以西藏高原高寒草原生态系统的4个自然地带(高山草原、高山灌丛草甸、山地半荒漠与荒漠以及山地灌丛草原)的19个草地型植被为研究对象,采用野外调查与室内分析相结合的方法,对高寒草原生态系统植被C/N值的分布特征及其影响因素进行了研究。结果表明:西藏高原高寒草原植被C/N值总体上呈现出东西部低而中间高的态势以及斑块状交错分布的格局。不同自然地带间和不同草地型间植被地上部分和根系的C/N值有明显差异,且地上部分的C/N值均大于根系。19个草地型植被地上部分的平均C/N值为34.17,变异系数为35.87%;根系的平均C/N值为29.58,变异系数为40.02%。4个自然地带植被地上部分的平均C/N值为31.98,变异系数为13.82%;根系的平均C/N值为31.86,变异系数为16.92%。回归分析结果显示:植被地上部分C/N值与地上部生物量以及土壤全N和全K含量呈显著正相关、与植被高度呈显著负相关;根系C/N值与海拔和20~30em土壤容重呈显著正相关、与年均降水量和年均蒸发量呈显著负相关,这些因子均为影响西藏高原高寒草原植被C/N值的关键环境因子。总体上看,地理因子、气候因子和土壤物理因子对西藏高原高寒草原生态系统植被C/N值的影响不显著,而植被因子和土壤化学因子则对其有显著影响。  相似文献   

2.
The Irano-Turanian floristic region is a major center of endemism in the Holarctic of Eurasia. The Alborz Mountains of northern Iran are a complex and heterogeneous environmental system with rich water resources and great habitat diversity. We have investigated steppe plant communities along an altitudinal gradient ranging from approximately 1,000 m a.s.l. in the semi-desert steppes near Tehran to a height of 3,966 m a.s.l. at the summit of Mount Tochal. Our two-way indicator species analysis of 1,069 vegetation samples resulted in classification of five major vegetation zones: (1) a semi-desert Artemisia steppe near Tehran, (2) a Stipa grassland in the alluvial undulating hills north and west of Tehran, (3) a submontane and steppe zone, (4) a subalpine cushion formation zone and (5) an alpine meadow and subnival zone of Mount Tochal. Annuals and ephemerals in the semi-desert vegetation decline as altitude increases and almost disappear in the alpine zone. Past human impacts of ancient Persian civilization and a traditional pastoral economy have affected the physiognomy of plant communities; thorny dwarf shrubs now dominate the treeless vegetation of the region. Lower competition for space, different phenology and the presence of edaphic and hydrological layers associated with anthropogenic impacts are major reasons for entanglement of different plant communities in the arid- and semi-arid steppe. The phytogeography of the region changes from omni-Irano-Turanian and Saharo-Sindian transgressive species at lower altitudes to a more limited range of western Irano-Turanian species and local endemics at higher altitudes.  相似文献   

3.
新疆北塔山植被的初步研究   总被引:3,自引:0,他引:3       下载免费PDF全文
本文对位于中蒙边境的北塔山地区的植被类型进行了初步的研究,并在此基础上对该地区的植被与相邻地区的植被从水平地带规律性、垂直地带规律性和植物区系成分上进行了对比分析,发现北塔山的植被无论在类型上还是在区系上都具有明显的过渡性和干旱性的特征。其植被垂直带结构为荒漠、山地荒漠草原、山地灌丛草原、山地草原和嵩草高山草甸。此外还对北塔山植被的特点及草场资源利用进行了探讨。对本区的研究,有助于人们对准噶尔盆地东端的北塔山区(很少有人进行科学考察的地区)的植被有所了解,同时对该地区的草场资源的利用和野生动物的保护,均有其重要的意义。  相似文献   

4.
天山北坡植物土壤生态化学计量特征的垂直地带性   总被引:6,自引:0,他引:6  
生态化学计量工作专注于植物与土壤的元素比例关系及其环境解释等问题上,还需要分析在连续环境梯度上元素比例关系的变化规律以进一步加深已有的认识。受水热梯度的影响,植被与土壤在天山北坡均存在明显的垂直地带性,这为探讨植物土壤生态化学计量特征的垂直带谱提供了有利条件。在天山中段北坡海拔1000—3840m范围内,按海拔梯度对植物和土壤分别采样,测定其C、N、P含量。结果表明:(1)随海拔的升高,植物C、N、P含量及其计量比变化规律各不相同,C含量随海拔变化保持不变,仅山地针叶林显著低于亚高山灌丛草甸、高山垫状植被和山前灌木(P0.05);N含量、C∶P、N∶P随海拔先升高后降低,山地针叶林和亚高山灌丛草甸显著高于山地荒漠草原、山地草原、高山垫状植被(P0.05);P含量、C∶N则是随海拔先降低后升高,高山垫状植被显著高于其他植被类型,山地荒漠草原、山前灌木和高山草甸显著高于山地草原、针叶林和亚高山灌丛草甸(P0.05)。(2)从生活型角度,乔木、灌木和草本C、N含量、C∶N差异不显著,灌木P含量、C∶P、N∶P显著高于草本(P0.05);乔木和灌木更受P限制,草本更受N限制。(3)随海拔的升高,土壤C、N、P含量、C∶P、N∶P均先升高后降低,其中山地针叶林和亚高山灌丛草甸均显著高于山地荒漠草原和山地草原(P0.05),土壤C∶N表现为一直降低,山地荒漠草原显著高于其他植被类型(P0.05)。(4)植物C、N、P及计量比与土壤相关性分析中,仅植物C∶P与土壤C∶P相关性显著,且植物C、N、P含量与土壤相关系数小于植物C∶P、N∶P与土壤相关系数。在垂直地带性上,土壤主要通过生态化学计量比影响植物的生长。  相似文献   

5.
对新疆天山中段巴音布鲁克高山草地(高山草原和高山草甸)的生物量和土壤有机碳进行了测定。结果表明积分和分层两种估算方法得到的土壤有机碳含量没有显著差异,但积分算法的优势在于能推算不同深度的土壤有机碳含量,便于与以往的研究进行比较;高山草甸的生物量和土壤有机碳含量均大于高山草原;其地上生物量分别为71.4和94.9 g C·m-2,地下生物量分别为1 033.5和1 285.2 g C·m-2; 1 m深度的土壤有机碳含量分别为25.7和38.8 kg·m-2;地上生物量呈现较为明显的垂直分布格局,即随着海拔的增加,地上生物量先呈增加趋势,但当海拔超过一定界限后生物量突然下降;土壤含水率是导致南坡(阳坡)土壤有机碳含量空间分异的重要因素,但北坡(阴坡) 土壤有机碳含量还可能与地形、土壤质地等其它因素有关;两种高山草地(高山草原和高山草甸)的根系集中分布在40 cm以内,0~20 cm根系分别占其总量的76%和80%;土壤有机碳集中分布在60 cm以内,0~20 cm土壤有机碳分别占其总量的55%和49%;高山草原根系分布比高山草甸深,但较低的地下/地上比使得其有机碳分布比高山草甸浅。  相似文献   

6.
Question: Is the vegetation of meadow and mountain steppes distinct from the ground vegetation of light taiga forests in the transitional zone between these biomes? Location: Western Khentey Mountains, northern Mongolia. Methods: Vegetation was recorded from 100‐m2 plots from all dominant types of light taiga forest and dry grassland. Distinctness of ground vegetation was studied with Detrended Correspondence Analysis (DCA). Results: Ground vegetation in the light taiga was significantly different from the herbal vegetation of meadow and mountain steppes. Clear separation was only absent for the Car ex amgunensis meadow steppes that occur in a narrow strip along the forest edge and are partly shaded by trees. Forest and steppe communities followed a moisture gradient according to the DCA ordination with light taiga forests at the moistest sites and steppe communities at the driest sites. Ulmus pumila open woodlands diverged from this pattern, because of their close spatial and phytosociological relationship to mountain steppes. Conclusions: The present results do not support the assumption that grasslands in Mongolia's transitional zone between forest and steppe would generally resemble the ground vegetation of light taiga forests. This contradicts a published hypothesis stating that the vegetation of meadow and mountain steppes would not clearly differ from ground vegetation of light taiga forests in the forest‐steppe transitional zone of Mongolia.  相似文献   

7.
不同海拔梯度高寒草地地下生物量与环境因子的关系   总被引:8,自引:0,他引:8  
以新疆天山南坡的巴音布鲁克高寒草地为对象, 研究了不同海拔梯度高寒草地地下生物量的变化及其与环境因子的关系.结果表明: 随着海拔的升高, 高寒草原、高寒草原化草甸和高寒草甸的地下生物量逐渐增大, 二者呈极显著正相关( P<0.01 ).地下生物量从表层至底层逐渐递减,呈“T”形分布.高寒草原、高寒草原化草甸和高寒草甸0~10 cm土层的地下生物量分别占总地下生物量的68.1%、84.1%和86.7%.地下生物量与大气温度呈极显著负相关, 与相对湿度和土壤含水量呈极显著正相关(P<0.01 ), 而与有机质、速效氮和pH等无显著相关.  相似文献   

8.
There are two important allocation hypotheses in plant biomass allocation: allometric and isometric. We tested these two hypotheses in an alpine steppe using plant biomass allocation under nitrogen (N) addition and precipitation (Precip) changes at a community level. An in situ field manipulation experiment was conducted to examine the two hypotheses and the responses of the biomass to N addition (10 g N m?2 y?1) and altered Precip (±50% precipitation) in an alpine steppe on the Qinghai–Tibetan Plateau from 2013 to 2016. We found that the plant community biomass differed in its response to N addition and reduced Precip such that N addition significantly increased aboveground biomass (AGB), while reduced Precip significantly decreased AGB from 2014 to 2016. Moreover, reduced Precip enhanced deep soil belowground biomass (BGB). In the natural alpine steppe, the allocation between AGB and BGB was consistent with the isometric hypotheses. In contrast, N addition or altered Precip enhanced biomass allocation to aboveground, thus leading to allometric growth. More importantly, reduced Precip enhanced biomass allocation into deep soil. Our study provides insight into the responses of alpine steppes to global climate change by linking AGB and BGB allocation.  相似文献   

9.
为了解草原植物群落物种多样性和植物地上生物量对氮沉降增加和降水变化的响应,在内蒙古贝加尔针茅(Stipa baicalensis)草原,分别设置对照(N0)、1.5 g/m2(N15)、3.0 g/m2(N30)、5.0 g/m2(N50)、10.0 g/m2(N100)、15.0 g/m2(N150)、20.0g/m2(N200)和30.0 g/m2(N300)(不包括大气沉降的氮量)8个氮素(NH4NO3)添加梯度和模拟夏季增加降水100mm的水分添加交互试验,研究氮素和水分添加对草原群落植物物种多样性和几种常见植物地上生物量的影响。结果表明:(1)氮素和水分的添加降低了草原群落植物物种多样性,且氮素和水分有显著的互作效应。在水分添加的条件下,随着施氮水平的增加,群落植物物种多样性减小;在无水分添加的条件下,随着施氮水平的增加,群落植物物种多样性呈先增加后减小的"单峰"变化趋势。(2)不同植物对氮素和水分添加的响应不同,随着施氮水平的增加,羊草地上生物量显著增加;贝加尔针茅、羽茅、糙隐子草、寸草苔和冷蒿先增加后减少,呈单峰曲线;星毛委陵菜、牧马豆、扁蓄豆和线叶菊地上生物量则逐渐减少。而且氮素和水分对贝加尔针茅、羽茅、扁蓄豆地上生物量有显著的交互作用。  相似文献   

10.
海拔对高山峡谷区土壤微生物生物量和酶活性的影响   总被引:2,自引:1,他引:1  
为了解土壤微生物生物量和酶活性随海拔的变化特征,以川西海拔1563 m到3994 m的高山峡谷区的干旱河谷、干旱河谷-山地森林交错带、亚高山针叶林、高山森林和高山草甸土壤为研究对象,采用原位培养法研究了5种不同海拔生态系统中有机层(0~15 cm)和矿质层(15~30 cm)土壤微生物生物量碳氮、土壤蔗糖酶、脲酶及酸性磷酸酶活性的变化.结果表明:有机层土壤中微生物生物量碳氮和3种土壤酶活性呈现出先增加后减少再增加的变化特征,从2158 m开始不断增加,到3028 m左右达到峰值后减少,在3593 m出现最小值后,逆势增加直到3994 m后再次减少;矿质层土壤的微生物生物量碳氮和3种土壤酶活性表现为亚高山针叶林(3028 m)>高山草甸(3994 m)>干旱河谷-山地森林交错带(2158 m)>高山森林(3593 m)>干旱河谷(1563 m).各海拔梯度土壤有机层的微生物生物量和酶活性显著高于矿质层.高山峡谷区土壤微生物生物量与土壤酶活性呈极显著正相关.土壤微生物生物量和土壤酶与土壤含水量、有机碳和全氮呈极显著正相关,土壤蔗糖酶与土壤全磷含量呈极显著正相关,土壤酸性磷酸酶与土壤全磷和土壤温度呈极显著正相关.可见,高山峡谷区海拔变化引起的植被和其他环境因子的变化显著影响了土壤生化特性.  相似文献   

11.
青海祁连地区不同生境类型蝶类多样性研究   总被引:43,自引:4,他引:43  
于1997-1999年对青海祁连地区不同生境类型中蝴蝶多样性进行了研究。研究中依据海拔高度、气候、土壤和植被的不同将该地区的蝴蝶生境划分为5种类型:山缘农田、山地草原、森林草原、高寒灌丛草甸、裸岩。共收集蝴蝶4367只,隶属于6科35属53种,计算了5种生境类型中蝶类物种丰富度、相似性系数、多样性指数,其中,蝶类物种丰富度由小到大的顺序为:裸岩(6种)<山地草原(13种)<森林草原(14种)<高寒灌丛草甸(22种)<山缘农田(H′=2.7071)、高寒灌丛草甸(H′=2.7734);森林草原和山缘农田的相似性系数最高(0.3704),其次为山地草原和高寒灌丛草甸(0.2500,裸岩与其他生境类型的相似性系数最低。  相似文献   

12.
中昆仑山北坡及内部山原的植被类型   总被引:3,自引:0,他引:3       下载免费PDF全文
 中昆仑山西始乌鲁乌斯河,东迄安迪河,东西迤逦600余公里,平均海拔高度6000m。该区有野生种子植物52科,211属,398种。植物区系以种类成份单纯、地理成份复杂为特征。北坡中山带和高山带下部年降水量300—500mm,草原带发育完整,尤以中段的策勒山地草原发育最好。草原带以上高寒荒漠不存在,高寒草甸则有一定发育。中昆仑山北坡植被类型的垂直带谱是:1)山地荒漠,自山麓线多在2200—2500m,个别在3000m;2)山地荒漠草原在3000—3200m;3)山地真草原在3200—3600m;4)高寒草原在3600—3800m(阳坡上升到4200m以上);5)高寒草甸在3800—4200m;6)高山垫状植被仅见于东段山地和高寒草甸复合分布;7)高山流石坡稀疏植被在4200—5000m。中昆仑山内部山原极端寒冷干旱,多为砾漠所占据,高寒荒漠和高寒荒漠草原呈片状星散分布。  相似文献   

13.
高寒草地碳储量及其影响因素研究是认识青藏高原草地生态系统乃至陆地生态系统碳循环和气候变化的关键之一。利用2021年8月上旬地面调查数据与同期高分6号遥感数据建立回归关系,在反演研究区植被地上、地下生物量碳密度和0—40cm土壤层有机碳密度基础上,估算了黄河源园区高寒草地有机碳储量,并通过路径分析探讨了土壤理化性质对碳密度的影响驱动机制。结果表明:(1)2021年黄河源园区地上生物量、地下生物量、0—40cm土壤层碳密度分别为37.65g/m2、1305.28g/m2、4769.11g/m2;总碳储量为100.44Tg(1Tg=1012g),植被层和土壤层碳储量分别分为22.06Tg、78.38Tg,占总碳密度的21.96%、78.04%。(2)黄河源园区高寒草甸和高寒草原两种草地类型地上生物量碳密度分别为41.27g/m2、30.76g/m2;地下生物量碳密度分别为1661.41g/m2、618.74g/m2;0...  相似文献   

14.
叶永昌  周广胜  殷晓洁 《生态学报》2016,36(15):4718-4728
定量评估气候变化对内蒙古草原植被分布及其净第一性生产力的影响有助于理解干旱区域生态系统结构和功能对气候变化的响应。基于最大熵模型(MaxEnt)评价了气候因子的重要性,进而模拟了1961-2010年内蒙古草原植被的地理分布,同时应用综合模型模拟了净第一性生产力变化。研究表明,湿润指数(MI)、年降水量(P)、最暖月平均温度(Tw)和最冷月平均温度(Tc)是决定草原植被分布的主导气候因子。1961-2010年内蒙古草甸草原、典型草原和荒漠草原分布面积分别减少了5%、1%和62%,草原面积整体减少了11%,预示着草原向着荒漠化的方向发展。降水是决定内蒙古草原净第一性生产力变化的最重要因素。  相似文献   

15.
藏北高原典型植被样区物候变化及其对气候变化的响应   总被引:7,自引:0,他引:7  
植被物候作为陆地生态系统对气候变化的响应和反馈的重要指示,已成为区域或全球生态环境领域研究的热点。基于非对称高斯拟合方法重建了2001—2010年MODIS EVI时间序列影像,利用动态阈值法提取藏北高原植被覆盖2001—2010年每年关键物候参数。选取研究区内东部高寒灌丛草甸、中部高寒草甸及西部高寒草原和高寒荒漠4种典型植被类型,并结合附近的4个气象台站气候资料,分析典型植被物候在近10a对关键气候因子的响应特征。研究结果表明:(1)4种不同典型植被的物候特征(EVImax降低、返青期延后和生长季长度缩短)均表现出高寒灌丛草甸→高寒草甸→高寒草原→高寒荒漠草原的过渡;(2)藏北高原近10a的年平均气温及春、夏、冬三个季度的平均气温均呈显著升高的趋势,升温幅度在0.8—3.9℃/10a,降水减少趋势不显著,在这种水热条件下典型植被均表现出返青提前(7.2—15.5d/10a)、生长季延长(8.4—19.2d/10a)的趋势,而枯黄出现时间为年际间自然波动;(3)高寒灌丛草甸EVImax主要受春季降水量和气温影响,且降水的影响程度大于气温;对高寒草甸植被而言,春、夏季的气温和降水均有较大的影响;而高寒草原和高寒荒漠草原主要受夏季平均气温和降水量影响;(4)高寒灌丛草甸的返青时间主要受前一年秋季降水量的影响,相关系数达-0.579;而高寒草甸、高寒草原和高寒荒漠草原主要受春季平均气温影响,高寒荒漠草原的特征最为明显(r=-0.559)。  相似文献   

16.
A study on the vegetation in the east side of Helan Mountain   总被引:7,自引:0,他引:7  
Yuan  Jiang  Muyi  Kang  Shuo  Liu  Lianshu  Tian  Mingde  Lei 《Plant Ecology》2000,149(2):119-130
This paper analyzed the vegetation data obtained from a field survey conducted in the East Side of Helan Mountain, China, to reveal the features of mountainous vegetation growing in a transitional zone between the steppe and desert regions. Detrended correspondence analysis (DCA) was applied to the process of analysis, to clarify the spatial variation of floristic composition of the vegetation in the lower mountain range.The preliminary results obtained from the analysis are: (1) There are 53 vegetation formations existing in the area, following the China's criteria of vegetation classification system. (2) Those vegetation types compose a vertical vegetation spectrum in the East Side of Helan Mountain due to the climatic gradient caused by elevation variation. The spectrum consists of 4 zones. They are, from the foot up to the peak in turn, mountain steppe zone, mountain open forest and steppe zone, mountain coniferous forest zone, and alpine bush and meadow zone. The mountain coniferous forest zone can be further divided into two subzones: Pine forest subzone and Spruce forest subzone. (3) Most of the vegetation types show clear xeromorphic features due to the base zone of the vertical vegetation spectrum lying in the arid region of China. (4) The distribution of vegetation types and flora is sensitive and susceptible to the moisture condition that the vertical vegetation spectrum has quite different expressions between northern and southern exposures. (5) Floristic composition of the vegetation shows a northern temperate feature. The families that are rich in species in the area include Gramineae, Compositae, Leguminosae, Chenopodiaceae, Rosaceae and others, most of which are abundant in herbaceous species. (6) The variation of the ecological conditions from the north to the south also leads to the differentiation of vegetation and its floristic composition in the area. (7) The broad-leaved forest can not form a forest zone in the vertical vegetation spectrum. This may be a special characteristic of the spectrum sitting on a transitional zone between the steppe and desert regions.  相似文献   

17.
Question: What is the impact of grazing regime on plant species abundance, plant growth form, plant productivity and plant nutrient concentrations in a forest steppe? Location: Hustai National Park in the forest steppe region of Mongolia. Methods: On the Stipa steppe we applied three different grazing regimes by using; (1) one type of exclosure which excluded grazing by large mammalian herbivores, mainly takh (Przewalski horse), (2) another type of exclosure that excluded both large and small (Siberian marmots) mammalian herbivores, and (3) control plots which were freely grazed. We measured species frequencies, tiller densities, plant biomass and nitrogen concentrations of the vegetation. Results: Exclusion from grazing by takh and marmots significantly increased plant standing crop, but marmot grazing and full grazing did not show significant differences. Protection from grazing decreased forage quality, shown by a lower N-concentration of the standing crop. However, this was solely the result of the lower live-dead ratio of the vegetation. The frequency of the rhizomatous Leymus chinensis decreased under reduced grazing, as did the frequency of the total of rhizomatous species. The frequency of Stipa krylovii increased under reduced grazing, as did its basal areas, tiller density and tussock height. Conclusion: Reduced grazing leads to a lower abundance of rhizomatous species and an increase in tussock species.  相似文献   

18.
新疆阿勒泰地区草地资源可持续管理分析   总被引:1,自引:0,他引:1  
通过分析新疆阿勒泰地区草地资源的利用现状,草地类型的生产性能、生态服务价值和在区域发展中的主导功能,指出分类经营是该区草地资源可持续管理的有效途径。研究表明,阿勒泰地区的草地资源在空间上可划分为生态功能区(高寒草甸和草原、沼泽、山地荒漠草原、山地草原化荒漠和部分平原荒漠),经济功能区(山地草甸,低地草甸和草甸草原)和混合功能区(山地草原、平原荒漠草原和大部分平原荒漠),在时间上可采取不同的经营策略。生态功能区经营策略是禁牧和封育,经济功能区的经营策略是通过施肥、灌溉等手段,集约化管理,提高单位面积产值I混合功能区的经营策略是以草定畜,合理轮牧。  相似文献   

19.
Spatial patterns of herbaceous biodiversity in Mongolia steppe were examined and explained with biotic and abiotic factors including climate, livestock grazing, and fire disturbance. Vegetation data were collected from 63 sites across different steppe types (i.e., semi-desert, typical, and forb steppes) in 2012 and 2013. Three categorical (three steppe types, burned or not, grazed or not) and three continuous variables (precipitation, vegetation productivity, site-camp distance) were developed from national climate and GIS database of Mongolia and two satellite sensor products: Tropical Rainfall Measuring Mission (TRMM) precipitation and June-to-August accumulated Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVIJJA). The prescribed factors were utilized to examine single- and multiple-factor effects on biodiversity and community structure, by using correlation, stepwise multiple regression analysis, and ordination. Our results indicate the positive effect of precipitation and fire but negative effect of grazing on biodiversity in our study region. Localized herding effect was recognized to areas less than 1.5 km away from the herder's camp sites. Fire, precipitation and productivity (NDVIJJA) were identified as important factors affecting biodiversity of remote regions. Based on the results, we infer that pastureland biodiversity of Mongolia is controlled by region-scale variations of climate and vegetation productivity, but locally modified by intensive livestock grazing pressure with different grazing sensitivity for different steppe types.  相似文献   

20.
吴江航  李洋  王迎新  刘向  孙建 《生态学报》2024,44(2):793-804
植物生产力分配和权衡是植物生态学研究中的热点,反映植物对环境的适应性,是了解植物响应全球气候变化的关键。青藏高原作为气候变化敏感区,研究其植物地上与地下部分权衡对了解高寒草地植被生存策略和生态系统可持续发展具有重要意义。目前,生物量分配调控机制已被广泛研究,但主要使用植物根冠比和地上-地下生物量比等方法来表征植物分配模式,缺乏考虑因植物生长周期导致的差异。使用青藏高原高寒草地103个样点的地上和地下净初级生产力数据,分析高寒草甸和高寒草原两种主要草地类型的地上-地下净初级生产力权衡关系。利用气候因素和土壤因素等相关数据,结合方差分析、相关分析、相对重要性分析和结构方程模型的方法,探究环境因素对两种草地类型地上-地下净初级生产力权衡的影响机制。研究发现:(1)高寒草甸的地上净初级生产力、地下净初级生产力和土壤养分含量显著高于高寒草原(P<0.05);(2)高寒草地植被生产力均向地下权衡(0.0199),且高寒草原(0.0354)的权衡值高于高寒草甸(0.0173);(3)结构方程模型发现,年平均降水量、土壤容重和土壤速效氮含量是影响高寒草甸生产力权衡的主导因子,而年平均温度和年平均降水量是影响高寒草原生产力权衡的主导因子。研究表明高寒草甸的生产力权衡主要受气候和土壤因素共同影响,而高寒草原主要受气候因素调节。研究为理解植物地上-地下生物量分配调控机制提供了新的视角和方法,对系统了解高寒草地生物量分配模式和准确预测高寒草地植被动态过程具有指导意义。  相似文献   

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