农业区域市化对植物多样性的影响：遵化的研究

选择河北省遵化市(39°55'～40°22'N,117°34'～118°14'E),调查了城郊和乡村在东南西北4个方向上以及市区的植物多样性,同时考察了不同取样点土壤养分的差异结果表明,西部和北部接近,而东部和南部的土壤养分特殊,城郊与乡村明显差异;西部物种丰富度低于其它方向,而南部最高,这种差异由草本造成;城市与东南西北4个方向的生物多样性差异明显;城市植物多样性与城郊和乡村呈现梯度变化;本研究统计的物种总数只有126种,而与之同纬度的北京东灵山区却有高等植物997种.城市化的影响是引进了一些观赏物种,区域地形和土壤养分等自然特征的影响微弱.     

杨属物种多样性在中国的地理分布格局

利用地理信息系统技术与空间统计相结合的方法,研究了杨属物种多样性在中国区域尺度上的空间分布格局,并且采用线性回归分析方法研究了杨属物种多样性与经纬度的关系。结果表明:(1)杨属物种在中国呈带状分布,东西分布幅度大于南北分布幅度;(2)纬度梯度上杨属物种集中分布区位于30—40°N,经度梯度上位于110—120°E,说明杨属物种多样性格局在经、纬度梯度上并非单调递增或递减,而是在某一最适区域具有最高的物种多样性;(3)中国杨属物种多样性的分布中心集中于东北—西南方向的黑河-腾冲线两侧,从黑腾线向西北和东南方向延伸过程中,物种多样性逐渐降低;沿黑腾线从东北向西南方向物种多样性呈增加趋势;(4)从分组、分种检索上看,白杨组和青杨组物种在中国分布范围最广,山杨、小叶杨、响叶杨和青杨4种物种分布范围最广,可见同一类群中不同分类等级的植物多样性地理分布格局存在差异。     

三江源地区不同建植期人工草地植被特征及其与土壤特征的关系

研究了三江源地区不同建植期人工草地群落生物量、物种组成、多样性指数和土壤理化特征,并用多元逐步回归分析法探讨了土壤理化特征对群落生物量、多样性变化的响应.结果表明:研究区不同建植期人工草地植物群落的种类组成、植物功能群组成和群落数量特征存在显著差异;土壤含水量随着物种多样性指数的增加而增加,土壤容重随着物种多样性的增加而减小;土壤微生物生物量碳与土壤含水量、土壤有机质呈极显著正相关,与土壤容重呈极显著负相关;土壤有机碳含量明显呈"V"字型变化,且与土壤含水量的变化趋势相一致,随土壤容重的增加而减少;群落生物量与土壤养分和土壤含水量之间呈显著正相关,群落地上、地下生物量的增加有利于提高土壤养分含量.     

不同生态保护地植物特征和土壤性质的对比研究——以黑河中游湿地为例

选择黑河中游张掖国家湿地公园和张掖黑河湿地国家级自然保护区为研究对象,对比分析了植物组成、物种多样性、植物生长状态、土壤养分、土壤理化性质及植物土壤间关系。结果显示:湿地公园的植物高度和土壤养分含量(有机碳、全氮、速效氮、全磷、速效钾)显著高于自然保护区,土壤理化性质含量(容重、pH)显著低于自然保护区,表明湿地公园有利于植物生长发育、土壤养分固存、改善土壤质地;自然保护区的植物科属种、多度、物种多样性(多样性指数、丰富度指数、均匀度指数)显著高于湿地公园,表明自然保护区有利于维持植物多样性;两种保护地中影响植物多样性的土壤因子不同,湿地公园物种多样性与土壤全磷和速效磷显著正相关,而自然保护区物种多样性与土壤盐分显著负相关。     

城市化对植物多样性影响的研究进展

本文综述了城市化对植物多样性影响的研究进展。随着全球特别是发展中国家城市化水平的提高, 城市化对生物多样性的影响逐渐引起了人们的重视。城市化造成了本土植物物种的丢失和外来物种的增加。在空间分布上, 城市化还常使城区本土植物多样性沿着远郊农区－城郊－城区梯度性下降; 但是由于引进大量外来物种, 总体植物多样性反而升高, 沿着远郊农区－城郊－城区梯度性升高。城市化对植物种类组成也有很大影响,优势种在远郊农区、城郊和城区呈现不同。城市化对植物多样性影响的机制主要有人为引入外来物种、小生境改变以及景观格局的变化三个方面。以下四个研究方向将越来越重要: (1) 不同区域、不同方法、不同学科的系统整合研究;(2) 城市化扩张与植物多样性变化过程的定位监测研究; (3) 本土植物多样性丢失以及性状改变的内在机制研究, 特别是外来物种与本地物种的相互作用过程和机制的研究; (4) 城市植物多样性保护研究。     

河北太行山低山丘陵区植被恢复过程中物种多样性与土壤养分变化

采用野外调查与室内试验相结合的方法,以1986年和2008年调查数据为基础,分析了植物组成与种群结构的变化,运用Shannon多样性指数、丰富度指数、Pielou均匀度指数对太行山低山丘陵区植被物种多样性进行分析,并探讨了土壤养分变化及其与植物物种多样性的相关性。结果表明:1)植被恢复22年后,群落结构和物种组成发生了明显的变化,群落逐渐由草本向乔灌木转变,且草本植物的物种数显著减少;2)灌木的盖度和生物量显著增加,引起灌下小环境的改变,使湿生草本植物明显减少,从而导致物种多样性和丰富度指数降低;3)植物物种多样性主要受土壤有机质、全N、全P、全K、全Ca和全Mg含量的影响。封山育林22年以后,群落结构渐趋合理,生物量显著增加,物种多样性有所减少,并且对土壤表层的养分产生了明显的回馈作用。     

古尔班通古特沙漠南部植物多样性的区域差异

植物多样性分布受环境影响,具有尺度依赖性,研究不同区域植物多样性的差异和分布规律有助于剖析群落多样性的整体形成和变化原因,进而为实施有效的保护和利用提供科学依据。以古尔班通古特沙漠植物多样性集中分布的南部为研究区,沿经向方向划分3条样带(绿洲边缘样带、克拉玛依至吉木萨尔的沙漠公路样带以及距离二者之间的沙漠腹地样带),同时根据沙垄高度、走向和生境差异将研究区划分为5个分区,对比研究各样带、各分区的α、β多样性特征及物种共性和差异性。结果表明:3条样带的α多样性变化为绿洲边缘样带沙漠公路样带沙漠腹地样带。随经度的增加,各样带的物种相似性和替代性特征表现相似的变化趋势。物种分析发现沙漠公路样带内短命植物分布较多,绿洲边缘样带以多年生草本和灌木群落为主,而沙漠腹地样带介于二者之间。各分区间的物种组成存在一定差异。沙漠西部、东部、莫索湾垦区附近、沙漠腹地等分区物种丰富度均较高,而古玛纳斯湖区的植物丰富度较低,与其余4个分区间的物种相似性小,相互替代性较强。总结认为古尔班通古特沙漠南部各分区间植物多样性受地史过程的影响较大,而样带间植物多样性受土壤质地、降水量等环境因素影响较大;沙漠东部似是整个南部沙漠的物种扩散中心。     

不同经营措施对黄龙山辽东栎林的影响

以黄龙山林区蔡家川林场的辽东栎群落为研究对象,以未采伐为对照,采取皆伐、间伐30%、间伐15%三种经营措施,在进行自然恢复6年后,对辽东栎林建群种径级结构、群落物种多样性、土壤养分水分状况进行了对比分析,以探讨不同经营措施对黄土高原南部辽东栎(Quercus liaotungensis)林群落多样性的影响.结果表明:不同经营措施实施后建群种径级结构、群落物种多样性、土壤养分水分等指标均与未采伐林地有差异;经过间伐30%的林地,建群种径级结构、群落物种多样性、土壤养分水分等指标均有显著增加;间伐15%林地上述指标均有增加,但不显著;皆伐后的林地相对未采伐林地,建群种径级结构、群落物种多样性、土壤养分水分等指标降低.间伐与皆伐措施后比较,间伐措施的林地建群种个体生长发育良好,林下有大量幼苗,林地物种多样性丰富,土壤养分水分相对优越;皆伐措施的辽东栎建群种个体发育不良,缺乏足够数量的幼苗,林分物种多样性、土壤水分养分相对较差.未来该地区辽东栎林经营管理中,应以近自然经营措施为主,尽量减少对灌草层破坏,完善群落复层结构;间伐强度拟定为30%,尽量间伐劣质木、病虫木,促进群落向异龄方向发展.     

荒漠草原中间锦鸡儿林土壤养分效应对群落组分和多样性的影响

为系统认识荒漠草原中间锦鸡儿人工林草本植被特征及演变趋势对土壤养分的响应,采用空间代替时间的方法,以天然草地为对照,构建3个中间锦鸡儿林龄(16a、25a、37a)研究序列,调查不同中间锦鸡儿林灌丛内外土壤植被并分析二者之间的关系。结果表明:(1)随林龄增加,不同功能群植物重要值呈不同变化趋势,其中禾本科植物显著增加,豆科植物显著降低,杂草类植物先减小后增加。(2)α多样性分析显示,荒漠草原中间锦鸡儿人工林16a灌丛外物种丰富度(S)、香浓维纳指数(H)最高(P0.01);不同林龄均匀度指数(J)、优势度指数(P)未表现出明显的变化规律。(3)β多样性分析显示,Cody指数(βc)和Morisita-Horn(CMH)相似指数均表现出16a与25a、37a之间的物种差异较大、25a与37a之间物种差异相对较小、37a中间锦鸡儿林与天然草地物种组成相似,βws指数在25a中间锦鸡儿林最大。(4)人工中间锦鸡儿林存在显著的土壤碳氮"肥岛效应",其中土壤有机碳是不同林龄植物群落组成差异的显著性影响因子,土壤速效氮为不同林龄灌丛外植物多样性差异的显著性影响因子,但灌丛内植物多样性对土壤养分的响应并不显著。研究认为,中间锦鸡儿林土壤养分演替正效应提高了植物多样性,增强了植物物种的更替程度,但建植后期(37a)植物群落存在向天然草地演替趋势。     

四川小寨子沟森林群落物种多样性的环境梯度分析

运用去势典范对应分析法(DCCA),分析了四川小寨子沟自然保护区森林群落物种多样性指数与环境因子的关系.结果表明,群落物种多样性表现为草本层>灌木层>乔木层;海拔高度是群落乔木层物种多样性分布格局的主导因素,随着海拔高度的上升,乔木层物种丰富度和多样性下降,而均匀度没有明显变化;土壤有机质和土壤全氮代表的土壤养分状况决定着灌木层和草本层物种多样性的分布格局.地形因子(如坡度、坡向等)与物种多样性没有明显的关系.     

哈尔滨东部城乡土地梯度带的划分及景观结构

以哈尔滨市及东部郊区为对象,重点研究城乡土地梯度带的划分以及造成这种景观分异的内在机制,特别是对镶嵌在城市到乡村之间土地类型的数量变化,研究土地景观结构的特点.研究区范围东西35km,南北16km,在GIS平台上使用TM与SPOT卫星图像划分出东西2.5km,南北16km大小的14条等面积的连续梯度带,根据等面积梯度带的建筑密度和道路密度将研究区域划分为市区、近郊区、远郊区3个梯度区.应用计算机目视判读方法对研究区内进行了土地类型的识别及区划,利用GIS空间分析,计算了各种梯度带的内的不同土地类型的长度、面积.通过这些计算与分析研究了哈尔滨市及东部城乡之间不同梯度带的绿地景观空间结构特点,以绿地建设为核心,辅以城市景观结构及空间格局的特点,分析讨论不同城乡梯度带景观分异的成因.研究表明,区域道路密度和建筑物密度可以在一定程度上反应出城市化进程,据此将哈尔滨及东部城乡划分为市区、近郊区和远郊区;不同梯度区域有其各自的人文景观结构特点和绿地景观结构特点,讨论了造成这种梯度特征的内在机制,并对研究区域未来的城乡绿地及景观建设和可持续发展提出了建议.     

亚高寒草甸植物叶片生理指标对坡向的响应

研究了甘南亚高寒草甸不同坡向条件下矮嵩草、狼毒和棘豆叶片的叶绿素、游离脯氨酸和可溶性糖含量,以及稳定碳同位素(δ¹³C)的变化,分析干旱胁迫条件下,植物适应干旱胁迫的生理机制.结果表明: 随着坡向由北坡-西北坡-西坡-西南坡到南坡的变化,土壤含水量(北坡0.36 g·g^-1,南坡0.15 g·g^-1)呈降低趋势,土壤温度(北坡14.76 ℃,南坡24.85 ℃)和光照度(北坡540.34 lx,南坡744.12 lx)呈增加趋势;植物物种的组成也随之发生了变化,北坡主要有灌木金露梅及杂类草,而南坡主要有禾草类物种.3种植物叶片的脯氨酸、可溶性糖、叶绿素含量及稳定碳同位素(δ¹³C)随着坡向的变化均有不同程度的变化,且物种不同,各物种的生理指标变化幅度也有差异.在坡向梯度上,3种植物的脯氨酸、可溶性糖含量和稳定碳同位素与土壤含水量均呈显著负相关,与温度和光照强度呈显著正相关;植物叶片叶绿素与土壤含水量呈显著正相关,与温度和光照强度呈显著负相关.其中,土壤含水量是坡向梯度上影响植物生长的关键因子.植物叶片生理指标(脯氨酸、可溶性糖及叶绿素等)可以作为衡量植物抗逆性的因素,3种植物的抗性大小顺序为:矮嵩草>狼毒>棘豆.     

秦岭南坡锐齿栎林的生态环境及其营养积累

秦岭锐齿栎林 (含 0～ 6 0cm土层 )营养元素总储量达 182 .6 4 5～ 394 .70 1t·hm-2 ,植被占 0 .5 9%～2 .13% ;林分生物量为 131.713～ 5 0 3.82 2t·hm-2 ,乔木层占 92 .1%～ 99.2 % ;凋落物层现存量和营养元素积累量分别为 2 .897～ 33.999t·hm-2 和 10 4 .339～ 1136 .5 36kg·hm-2 .在一定范围内 ,林分生物量和营养元素积累量随密度的增加而增大 ;立地、林分条件相似的林分 ,生物量和营养元素积累量与林龄呈正相关 .林分针叶树占的比例越大 ,营养元素积累量越小 ,而且对生物量的影响远小于对营养元素积累量的影响 .在同一地区 ,立地、林分状况相似 ,林型不同 ,生物量及营养元素积累量差别不大 ,树种组成和林型不同林分的生物量和营养元素积累量均不同 .不同地区 ,生态和林分条件相似的林分的生物量和营养元素积累量也有差异 ;林型、结构相似林分生物量和营养元素积累量南坡 >北坡 ,中段 东段≈西段 .林分对营养元素利用率与海拔呈负相关 ,且南坡 >北坡 ,中段 >东西段 ,中段 >西段 >东段 .     

Identifying hotspots of endemic woody seed plant diversity in China

Aim This study aimed to detect distribution patterns and identify diversity hotspots for Chinese endemic woody seed plant species (CEWSPS). Location China. Methods Presence of 6885 CEWSPS throughout China was mapped by taking the Chinese administrative county as the basic spatial analysis unit. The diversity was measured with five indices: endemic richness (ER), weighted endemism (WE), phylogenetic diversity (PD), phylogenetic endemism (PE) and biogeographically weighted evolutionary distinctiveness (BED). Three levels of area (i.e. 1, 5 and 10% of China’s total land area) were used to identify hotspots, but the 5% level was preferred when both the total area of the hotspots identified and the diversity of CEWSPS reached by the hotspots were considered. Results Distribution patterns of CEWSPS calculated with the five indices are consistent with each other over the national extent. However, the hotspots do not show a high degree of consistency among the results derived from the five indices. Those identified with ER and PD are very similar, and so are those with WE and BED. In total, 20 hotspots covering 7.9% of China’s total land area were identified, among which 11 were identified with all the five indices, including the Hengduan Mountains, Xishuangbanna Region, Hainan Island, and eight mountainous areas located in east Chongqing and west Hubei, in east Yunnan and west Guangxi, in north Guangxi, south‐east Guizhou and south‐west Hunan, in north Guangdong and south Hunan, in south‐east Tibet, and in south‐east Hubei and north‐west Jiangxi. Taiwan Island was also identified as a major hotspot with WE, PE and BED. Main conclusions Hotspots of CEWSPS were identified with five indices considering both distributional and phylogenetic information. They cover most of the key areas of biodiversity defined by previous researchers using other approaches. This further verifies the importance of these areas for China’s biodiversity conservation.     

红砂根系分叉数和分支角度权衡关系的坡向差异

根系构型是决定根系分布及其对土体搜索效率的重要因素, 是植物与资源环境异质性相互适应的结果。利用ArcGIS建立研究区域的数字高程模型(digital elevation model), 采用全根系挖掘法, 研究了祁连山北坡荒漠草原不同坡向红砂(Reaumuria songarica)根系分叉数和分支角度的关系。结果表明: 不同坡向梯度草地群落的盖度、密度、高度和土壤含水量呈不同的变化趋势(p < 0.05), 红砂种群的密度、高度和根冠比等生物学特征的变化规律存在差异(p < 0.05); 不同坡向红砂根系分叉数和分支角度的相关性存在差异(p < 0.05), 在南坡和北坡红砂根系分叉数和分支角度之间存在极显著的负相关关系(p < 0.01), 在东坡和西坡根系分叉数和分支角度之间存在显著的负相关关系(p < 0.05), 红砂根系分配给根系分叉数和分支角度的资源存在着“此消彼长”的权衡关系; 随着坡向由南坡向西坡、东坡、北坡转变, 红砂根系分叉数和分支角度回归方程的标准化主轴斜率逐渐减小(p < 0.05), 红砂根系构型模式由扩散型转向聚集型。不同坡向红砂根系合理权衡连接长度和分支角度的资源配置模式, 反映了异质生境中植物种群应对资源多重竞争的环境生态适应机制。     

Trade-off relationship between root forks and branch angle of Reaumuria songarica on different aspects of slopes

Aims Root architecture is a major determinant in root spatial distribution and soil searching efficiency, may reflect plant strategies to adapt to the environments. Our objective was to examine the relationship between root forks and branch angle of Reaumuria songarica in response to slope aspects in the northwest of China.Methods The study site was located in desert grasslands on the northern slope of Qilian Mountains, Gansu Province, China. Survey and sampling were carried out along 20 belt transects. It were set up on sites of four different slope aspects at intervals of 30 m vertically from elevation 1940 m of the study area moving upward, 6 plots were set up flatly on site of each belt transect at intervals of 20 m. A handheld GPS was used to record longitude, latitude and altitude of each plot. ArcGIS was used to set up digital elevation model to extract the information of elevation, aspect, and slope for each plot. The traits of plant communities were investigated and 1 individual’s samplings of R. songarica were used to measure the root forks, root length and root branch angle in laboratory in each plot, and biomass of different organs was measured after being dried at 80 °C in an oven. The 120 plots were categorized into groups of south, west, east, and north aspects of slopes, and the linear regression analysis was then used to examine the trade-off relationship between root forks and branch angle in various groups.Important findings The results showed that with the slope aspect turned from south, west, east to north, the density, cover, height, above biomass and soil moisture content of the plant community displayed a pattern of initial increase, while the height, root-shoot ratio, root branch angle of R. songarica displayed a pattern of initial decrease, and the density, specific root length, root forks increase. The number of root forks was negatively associated with the branch angle, but the relationship varied along the aspect gradient (p < 0.05). There was a highly significant negative correlation (p < 0.01) between the root forks and branch angle on north slope and south slope, whereas less significant (p < 0.05) on the east slope and west slope. There is a trade-off relationship between the root forks and link length. In addition, when the slope aspect changed from south to west, east and north, the standardized major axis slope of regression equation in the scaling relationships between root forks and branch angle decrease (p < 0.05), indicating that the root architecture model of R. songarica by diffusion to gather. Consequently, the patterns of resource allocation between root forks and branch angle in different slope habitats reflected the mechanism of environment adaptation under conditions of multiple competitions for resources in plant populations.     

Using biological traits to assess how urbanization filters plant species of small woodlands

Question: Which biological traits (persistence, regeneration, dispersion traits and resource requirements) may explain the distribution of woodland flora along an urban–rural gradient? Location: The study was carried out in three medium‐sized conurbations of north‐western France: Angers, Nantes and Rennes. Methods: We sampled the vegetation of 36 small woodlands of about 1.5 ha composed of non‐planted vegetation along an urban–rural gradient. We characterized the position of woodlands along the urban–rural gradient by examining adjacent land cover. By using an ordination analysis (RLQ), we analysed which traits out of –23 tested were related to the contrasted distribution of species along the urban–rural gradient. Results: Species that are more likely to be found in urban woodlands than rural woodlands have different persistence traits (higher specific leaf area, more often rosette or semi‐rosette form, less underground vegetative multiplication), resource requirements (affinity for base‐rich and fertile soils) and regeneration traits (short life‐span). Dispersion traits were not related to the distribution of species along the urban–rural gradient. Conclusions: Our approach identifies traits that can help to determine the vulnerability of forest species as a result of the environmental changes that follow urbanization. Limiting the influence of the urban environment on habitat quality (particularly disturbance and soil enrichment) is likely to be of major importance in maintaining the plant biodiversity in woodlands.     

广西植物地理的基本情况和基本特征

<正> 广西处于北纬20°54′—36°20′,东经104°28′—112°04′之间。全区总面积23万6千平方公里,约占全国面积的2.46％。本区西靠云贵高原,南部濒临海洋,地跨热带和亚热带。地势东南低、西北高,因而河流主要是由西北向东南流入南海。广西境内群山环绕,在群山之中往往出现一些不大的盆地,在西江干流上亦有若干局部的小平原。广西大部分地区属于古老的地块—华夏陆台,因此,在海拔高度上,除东北和西北部以及中部、东部、东南部的弧形山脉、勾漏山脉和十万大山在500米以上者外,其余地区一般在500米以下,属丘陵地。区内超过2000米的山峰有五座。岩溶地形广泛发育,散布于区内各地,形成千奇百怪的岩溶地貌,构成广西地貌的主要特征之一。     

高寒草地甘肃臭草根系分形结构的坡向差异性

根系分形结构是植物根系构型应对环境异质性的表型可塑性结果, 可反映植物对生长环境的适应策略。利用ArcGIS建立研究区域的数字高程模型, 并提取坡向数据, 采用全根挖掘和Win-RHIZO根系分析仪相结合的方法, 研究了祁连山北坡高寒退化草地不同坡向甘肃臭草(Melica przewalskyi)的根系分形结构。结果表明: 随着坡向由北坡向东坡、西坡、南坡转变, 草地群落的密度、高度和土壤含水量逐渐减小, 甘肃臭草种群的密度、高度以及根系分形丰度呈逐渐增大的趋势、分形维数逐渐减小; 不同坡向甘肃臭草根系分形维数和分形丰度间的相关性存在差异(p < 0.05), 南坡和北坡甘肃臭草根系分形维数分形丰度之间存在极显著负相关关系(p < 0.01), 东坡和西坡之间存在显著负相关关系(p < 0.05), 甘肃臭草根系分形维数和分形丰度存在着“此消彼长”的权衡关系; 随着坡向由北坡向东坡、西坡、南坡转变, 甘肃臭草根系分形维数和分形丰度回归方程的标准化主轴(SMA)斜率逐渐增大(p < 0.05), 说明在干旱的南坡, 根系所开发利用的相同体积的土壤内, 根系分支更少、更稀疏。不同坡向甘肃臭草合理权衡根系分形维数和分形丰度的资源配置模式, 体现了植物根系构型构建的资源投资权衡机制。     

Fractal root system of Melica przewalskyi along different aspect in degraded grassland

Aims Fractal root system is phenotypic plasticity result of plant root architecture to respond to environmental heterogeneity, may reflect the growth strategy of plants to adapt to environmental conditions. Our objective was to explore the relationship between root fractal dimension and fractal abundance of fractal root system of Melica przewalskyi population in response to aspect variation in the northwest of China. Methods The study site was located in a degraded alpine grassland on the northern slope in Qilian Mountains, Gansu Province, China. Survey and sampling were carried out at 40 plots which were set up along four slope aspects transects with 20 m distance between adjacent plots. Handheld GPS was used to determine the elevation, longitude and latitude of each plot. ArcGIS was used to set up digital elevation model (DEM). Community traits were investigated and six individuals roots of M. przewalskyi were collected randomly at each plot. The samples were cleaned and divided into different organs, then scanning the root with the Win-RHIZO for measurements of fractal dimension and fractal abundance in laboratory, and their biomass were then measured after being dried at 80 °C in an oven. Important findings With the slope aspect turned from north to east, west, and south, the density, height and soil moisture content of the plant community displayed a pattern of initial decline, the height, density, root fractal abundance of M. przewalskyi increased and the root fractal dimension decreased. The root fractal dimension was negatively associated with the fractal abundance in all aspects, but the relationship varied along the slope aspects gradient; there was a highly significant negative correlation (p < 0.01) between the root fractal dimension and fractal abundance at north slope and south slope aspect, whereas the correlation only reached a significant level (p < 0.05) at the east slope aspect and west slope aspect; indicating that there is a trade-off between the root fractal dimension and fractal abundance. In addition, when the slope aspect changed from north to east, west and south, the standardized major axis (SMA) slope of the regression equation in the scaling relationships between root fractal dimension and fractal abundance increased (p < 0.05), indicating that the roots of M. przewalskyi at the droughty southern slope have less branch and more sparse in the same soil volume of root exploitation and utilization. Consequently, the resource allocation pattern on reasonable trade-off between root fractal dimension and fractal abundance in different slope aspect of M. przewalskyi, reflects the relationship between the income and the cost of construction of plant root architecture.