Shrub encroachment is transforming grassland ecosystems globally, yet the roles of shrub-herbaceous interactions, especially the independent effects of shrub canopy and root systems, in this process remain poorly understood, impeding effective management. We quantified the three-year shrub encroachment rate (2020−2023) and cumulative encroachment extent across 16 field-established cover gradients (5–80%). At each cover plot, we quantified unidirectional effects of shrubs on herbaceous species through manipulative experiments (shrub removal, canopy restriction, root exclusion, ambient control). These treatments isolated whole shrub effect, aboveground effect, belowground effect and synergistic canopy-root effects. In addition, we measured shrub functional traits to quantify encroachment mechanisms. Our analysis showed that the three-year encroachment rate followed a logarithmic pattern with hyperbolic decay in marginal encroachment rates, while cumulative encroachment extent presented an accelerating quadratic trend. Critically, we demonstrate asymmetric effects on encroachment: canopy mediation (explaining 44.0% variation) dominated belowground effects (28.3%). Partial correlation analysis confirmed a non-significant root effect after controlling for canopy effects. Functionally, taller shrubs drive faster encroachment, with height explaining 52.3% variation. Shrubs with more acquisitive leaf traits including higher specific leaf area and volume also facilitate encroachment, accounting for 13.1% and 34.6% of variance respectively. Our findings highlight that canopy-mediated interspecific competition is the primary force driving shrub encroachment. Practically, shrub canopy cover provides critical intervention metrics: <5% cover requires initiating shrub removal to disrupt shrub establishment dynamics, while between 5% and 13% requires immediate canopy thinning to maintain grassland productivity.

Alpine grasslands of the Tibetan Plateau rank among Earth's ecologically critical yet vulnerable ecosystems. These ecosystems sustain pastoral livelihoods and preserve nomadic cultural traditions. However, climate warming combined with intensified anthropogenic pressures is accelerating shrub encroachment in these ecosystems. For centuries, Tibetan pastoralists have counteracted this process through targeted interventions: manual uprooting of dominant shrubs, controlled patch burning during dormant seasons, and rotational grazing systems coupled with strategic herbivore deployment to suppress woody seedlings. Despite their shrub management efficacy, the scientific rationale underlying Tibetan traditional ecological knowledge-the role of shrub-herbaceous interaction variability in driving encroachment dynamics-remains understudied. We quantified shrub encroachment patterns across alpine meadows of the Zoige Plateau. Shrub encroachment dynamics were monitored across the elevation gradient (3400-3900 m), spanning the core elevational range of shrub encroachment. To identify shrub-herbaceous interactions in driving encroachment dynamics, we conducted a manipulative experiment with four shrub treatments: shrub removal, canopy restriction, root exclusion, and ambient control. Our analysis identified that elevation imposed a strong linear constraint on short-term encroachment rates (RSEIThree = -0.06E + 0.28, R 2 = 0.83, p < 0.001; E (elevation, km)). No significant elevational effect was observed on long-term encroachment rates (RSEIOutset; p > 0.05). Canopy competition (RIICanopy = 0.06E - 0.41, R 2 = 0.81, p < 0.001) mainly explained 60.6% of the variation in encroachment dynamics, while root competition (RIIRoot = -0.05E + 0.05, R 2 = 0.76, p < 0.001) accounted for 2.8%. Our findings highlight that canopy-mediated suppression of herbaceous plants is the primary pathway driving encroachment, while root-driven processes act as secondary mechanisms dependent on canopy architecture. Tibetan traditional methods directly disrupt key ecological drivers of shrub encroachment. By targeting shrub canopy removal, reducing herbaceous communities' light limitation, and weakening shrub competitive advantages that drive shrub encroachment, we promote the recovery of understory herbaceous communities.

IntroductionLight use efficiency (LUE) is a crucial determinant of plant productivity, while leaf functional traits directly affect ecosystem functions. However, it remains unclear how climate warming affects LUE and leaf functional traits of dominant species in alpine meadows.MethodsWe conducted a 4-year in-situ field warming experiment to investigate the eco-physiological characteristics for a dominant species (Elymus nutans) and a common species (Potentilla anserina) on the Tibetan Plateau. The leaf traits, photosynthesis and fluorescence characteristics were measured, along with the soil physical-chemical properties associated with the two species.Results and discussionsExperimental warming increased the leaf LUE, maximum photochemical efficiency, non-photochemical quenching, relative water content and specific leaf area for both species. However, there was a decrease in leaf and soil element content. Different species exhibit varying adaptability to warming. Increasing temperature significantly increased the photosynthetic rate, stomatal conductance, transpiration rate, total water content, and specific leaf volume of E. nutans; however, all these traits exhibited an opposite trend in P. anserina. Warming has a direct negative impact on leaf LUE and an indirectly enhances LUE through its effects on leaf traits. The impact of warming on plant photosynthetic capacity is primarily mediated by soil nutrients and leaf traits. These results indicate that the two different species employ distinct adaptive strategies in response to climate change, which are related to their species-specific variations. Such changes can confer an adaptive advantage for plant to cope with environmental change and potentially lead to alterations to ecosystem structure and functioning.

荒漠植物是干旱区具有独特功能性状与资源权衡表征的地带性植物。植物功能性状及其多样性格局与资源权衡策略对群落结构优化和生态系统功能改善起着关键作用。该综述主要从荒漠植物组织、器官功能性状特征、功能性状权衡策略、功能多样性组分及测度3个方面梳理了荒漠植物性状权衡策略与功能多样性研究的进展脉络：1)荒漠植物独特的根、茎、叶功能性状特征揭露了植被对环境变化的响应以及对生态系统功能的影响，基于植物功能性状的研究有助于解决许多生态学的关键性问题；2)作为植物功能性状之间存在的最普遍的联系，权衡策略是经过自然筛选后形成的性状组合，关键性状已经被发掘并创造性的提出了“经济谱”概念。荒漠植物研究过程中，应分析其根、茎、叶的特征属性筛选关键性状，着眼于关键性状间及整株植物性状间的权衡策略；3)功能多样性是影响生态系统运行和发挥作用的生物多样性的重要组成部分，荒漠植物功能多样性能预测和指示群落中物种对于荒漠生态系统功能发挥和过程变化的影响。功能多样性的组分可以从不同角度反映群落的生态位占据状况和资源利用程度，指数的选择要体现在群落内部物种的功能特征之间的差异程度，同时要考虑这些物种自身在群落内的优势程度。本研究为未来荒漠植物功能性状及多样性研究梳理了一些新的研究方向和内容，期望为荒漠植物生理生态学研究的选题和发展提供一些新的思路。

碳是贯穿自然和社会的首要元素之一,碳循环是自然和社会系统的重要纽带.陆地生态系统的自然固碳途径有2种,一种是植物碳同化,另一种是土壤碳同化,人们一直关注植物的有机固碳,对于土壤的无机固碳重视不够.本文回顾了中国荒漠区固碳能力强的C4木本植物和土壤无机固碳研究进展.通过解剖结构观察、δ13C值和气体交换特征全面分析得出,荒漠植物梭梭(Haloxylon ammodendron)和沙拐枣(Calligonum mongolicum)为典型的C4木本植物,梭梭同化枝有大量的含晶细胞,沙拐枣同化枝有大量的黏液细胞.干旱区荒漠的非生物固碳能力至今缺乏合理解释.通过对戈壁、沙漠和壤质荒漠土壤无机碳密度和碳储量分析,提出了土壤碳同化(soil carbon assimilation)概念,并给出了土壤碳同化途径的3个阶段,解释了土壤无机固碳这一现象;与植物碳同化比较,土壤碳同化是荒漠固碳的主要途径.最后,展望了荒漠C4木本植物和土壤碳同化的研究方向及对中国2060年前实现碳中和目标的可能贡献.

An automatic chamber (AC) is an alternative method to the eddy covariance (EC) technique for estimating of CO2 fluxes. However, few direct comparisons between two techniques have been performed on nature alpine meadows. In order to determine diurnal pattern of net ecosystem exchange (NEE) of CO2 in summer on alpine meadows, and test the NEE measurement performance of AC under site conditions, we conducted simultaneous measurements of NEE using both EC and AC methods. The NEEAC can be estimated with the information from the initial slope of the time series of CO2 mixing ratio. We found that the application of linear regression, when photosynthesis processes were considered, could lead to serious deviations, even if closure times were short. The linear regression, however, was adequate for estimating CO2 fluxes when photosynthesis processes were not involved in, at least for short chamber closing times. Using appropriate fitting method, the fluxes of AC were relatively close to that of EC, but presented a daytime underestimation and nighttime overestimation. With the subsequent friction velocity (u(*)) filtering (<m s(-1)), the nighttime overestimation was eliminated, and the fluxes of AC showed a similar diurnal pattern of NEE with that of EC, but an overall underestimation all day long. Here, we may provide a side evidence of the overestimation of chamber fluxes at low atmospheric turbulence. Finally, we assume that the overall underestimation of AC is caused by the absence of detection of effective volume of chamber.

Shrub expansion has been reported mostly in dry and semi-arid ecosystems worldwide. Shrub expansion is also a serious ecological issue in alpine and cold regions. Multiple drivers, including anthropogenic and environmental factors, contribute to this phenomenon. However, the relative effects of climate and soil factors on shrub expansion are incompletely quantified or understood in the alpine meadow, and quantifying how these factors result in variations in functional traits associated with shrub expansion is crucial considering that functional traits are tightly related to ecosystem processes. In this study, we investigated the vegetation of an alpine shrub meadow composed of Potentilla fruticosa L. In the Zoige Plateau, along an elevation gradient. We assessed the direct and indirect effects of climate and soil factors on functional traits, shrub expansion strength (measured as the total biomass), and relative abundance ( via functional traits). We found that climate factors, namely, the mean temperature of the warmest quarter (bio10), mostly affected specific leaf areas and specific lobe volume, which were the most important traits related to shrub expansion. Soil factors, except soil water content (SWC), had weak effects on functional traits closely related to shrub expansion. Our partial least square path modeling model explained 99% of the variation in shrub biomass. Results suggest that climate change not only affected functional traits but also influenced shrub expansion in the Zoige Plateau. Thus, management measures to control expansion should consider these drivers for more accurate forecasting and cost effectiveness. Understanding the mechanism of alpine shrub expansion contributes to the delaying of the expansion process and ensures steady pastoral production.

Poyang Lake is the largest freshwater lake in China and is characterized by significant intra-annual variation, with higher water levels and area in the wet season compared to the dry season. However, the effects of the seasonal variation in Poyang Lake on the local weather are still not well-recognized. With the help of the weather research and forecasting (WRF) model, we designed one control experiment (CTL) using the default Poyang Lake level and area data and two sensitivity experiments, EXPT1 and EXPT2, the former representing the higher lake level and the greater area of Poyang Lake in the wet season and the latter representing the lower lake level and the smaller area of Poyang Lake in the dry season, to assess how these changes affect the local weather. The results of EXPT1 show that, as the lake’s level and area increase, the latent heat flux (LH), the sensible heat flux (SH), and the land surface temperature (LST) in the lake area decrease compared to those of the CTL. Meanwhile, the planetary boundary layer height (PBL), the convective available potential energy (CAPE), the wind speed, and the vapor flux over the lake decrease as well, indicating increased atmospheric stratification stability and resulting in a domain-averaged decline in precipitation of −22.3 mm. However, the low lake level and less area in EXPT2 show increasing SH, LST, PBL, and wind speed, and decreasing LH and CAPE compared to those of the CTL. The increasing SH and weakened atmospheric stratification stability in EXPT2 cause a significantly higher wind speed over the eastern part of the lake. As a result, more water vapor is transported to the east side of the lake by westerly upper winds, leading to a decreasing precipitation on the western side of the lake and a slightly increasing precipitation on the eastern side, resulting ultimately in a domain-averaged decline in precipitation of −23.8 mm in the simulation of the low level and less area of Poyang Lake. Although the LH and CAPE decline both in EXPT1 and EXPT2, the main cause is the higher water thermal capacity and lower lake-surface temperature with more lake water for EXPT1 and the lower evaporation with less lake water for EXPT2. Overall, a deeper and larger Poyang Lake will reduce the local temperature, inhibit water evaporation from the lake surface, and make the near-surface atmosphere more stable, resulting in restrained local precipitation. A shrinking lake level and area will raise the local temperature and the instability of the near-surface atmosphere but reduce water vapor and enlarge local wind and circulation, resulting in declining precipitation and a changing fall zone.

The place of production is closely related to the quality, safety and nutritional quality of Lanzhou lily (Lilium davidii var. unicolor), and its geographical origin traceability and origin confirmation is beneficial to the implementation of the protection of the place of production, the fidelity of characteristic products and the sustainable development of the industry. In this study, isotope ratio mass spectrometry (IRMS) and inductively coupled plasma mass spectrometry (ICP-MS) were used to determine the ratios of 3 stable isotopes (δ13C, δ15N, δ18O) and the content of 16 mineral elements (K, Mg, Ca, Na, B, Fe, Zn, Al, Mn, Cu, Mo, Cr, Cd, Se, As, Pb) in samples from the four main producing areas of Lanzhou lily. Combining principal component analysis (PCA), orthogonal partial least squares discrimination analysis (OPLS-DA) and linear discriminant analysis (linear discriminant analysis, LDA), the classification model of Lanzhou lily from different producing areas was constructed to verify the geographical origin traceability and origin confirmation. The results of the study showed that: δ13C, δ15N, K, Mg, Na, B, Fe, Mn, Cu, Mo, Cr, Cd were significantly different among the production areas (P<0.05); 5 principal components were extracted by PCA analysis, and the cumulative variance contribution rate was 84.36%; LDA original discrimination accuracy rate was 100%; Leave-one-out cross validation (LOO-CV) discrimination accuracy rate was 88.89%; OPLS-DA model correct discrimination rate was 100%, of which the classification effect was optimal. This study shows that a multivariate statistical classification model based on the stable isotope and mineral element contents of Lanzhou lily can effectively distinguish lily from different production areas, promote the establishment and improvement of its traceability system, and is of great significance to the protection and quality control of Lanzhou lily's production area.

Identifying the mechanisms that underlie the assembly of plant communities is critical to the conservation of terrestrial biodiversity. However, it is seldom measured or quantified how much deterministic versus stochastic processes contribute to community assembly in alpine meadows. Here, we measured the decay in community similarity with spatial and environmental distance in the Zoige Plateau. Furthermore, we used redundancy analysis (RDA) to divide the variations in the relative abundance of plant families into four components to assess the effects of environmental and spatial. Species assemblage similarity liner declined with geographical distance (p < .001, R-2 = .6388), and it decreased significantly with increasing distance of total phosphorus (TP), alkali-hydrolyzable nitrogen (AN), available potassium (AK), nitrate nitrogen (NO3+-N), and ammonia nitrogen (NH4+-N). Environmental and spatial variables jointly explained a large proportion (55.2%) of the variation in the relative abundance of plant families. Environmental variables accounted for 13.1% of the total variation, whereas spatial variables accounted for 11.4%, perhaps due to the pronounced abiotic gradients in the alpine areas. Our study highlights the mechanism of plant community assembly in the alpine ecosystem, where environmental filtering plays a more important role than dispersal limitation. In addition, a reasonably controlled abundance of Compositae (the family with the highest niche breadth and large niche overlap value with Gramineae and Cyperaceae) was expected to maintain sustainable development in pastoral production. These results suggest that management measures should be developed with the goal of improving or maintaining suitable local environmental conditions.

Desert plants evolve different photosynthetic organs to adapt to the extreme environment. We studied the leaf and canopy gas exchange, chlorophyll content, fluorescence parameters, and anatomical structure of different photosynthetic organs (leaf and assimilating stem) on four desert plants ( Nitraria sphaerocarpa , Caragana korshinskii , Haloxylon ammodendron , and Calligonum mongolicum ). The results showed a higher net photosynthetic rate ( P N ) in the assimilating stems of H . ammodendron and C . mongolicum , which also had a higher light saturation point and a lower light compensation point than leaves ( N . sphaerocarpa and C . korshinskii ), suggesting more efficient solar energy utilization in the former. Within each species, canopy apparent photosynthetic rate (CAP) was significantly lower than P N , and the daily average CAP of the assimilating stems was significantly higher than leaves. These findings indicated that the photosynthetic response of desert plants was specific to photosynthetic organs. We concluded that the assimilating stem was a superior adaption for desert plants to survive the arid environments.

Asexual reproduction is the main mode of alpine plant reproduction, and buds play an important role in plant community succession. The purpose of this study is to explore whether the desertified grassland can recover itself through the existing bud bank. The bud bank composition, distribution and size of different desertified grasslands were studied using unit volume excavation on the Tibetan Plateau. The bud bank consisted of tiller, long and short rhizome buds, and more than 40% of buds were distributed in the 0–10 cm soil layer. Enclosure changed the bud density, distribution and composition. The bud densities were 4327 and 2681 No./m2 in light and middle desertified grasslands before enclosure, while that decreased to 3833 and 2567 No./m2 after enclosure. Tiller bud density and proportion of middle desertified grassland were the highest, increased from 2765 (31.26%, before enclosure) to 5556 No./m3 (62.67%, after enclosure). There were new grasses growing out in the extreme desertified grassland after enclosure. The meristem limitation index of moderate desertified grassland was the lowest (0.37), indicating that plant renewal was limited by bud bank. Plants constantly adjust the bud bank composition, distribution, and asexual reproduction strategy, and desertified grasslands can recover naturally, relying on their bud banks through an enclosure.

Soil properties affect plant growth and cause variation in leaf functional traits. Lycium ruthenicum Murray is one of the desert dominant shrubs and halophytes in the lower reaches of Heihe River, Northwest China. We analyzed the trade-off relationships of 14 leaf functional traits of eight L. ruthenicum populations growing at varying distances from the river and discussed the effects that soil properties have on leaf functional traits. The results showed that: Lower leaf nitrogen (N) content indicated that L.ruthenicum was located at the slow investment–return axis of the species resource utilization graph. Compared with non-saline and very slightly saline habitats, populations of slightly saline habitats showed a higher carbon to nitrogen ratio (C:N). Redundancy analysis (RDA) revealed a relatively strong relationship between leaf functional traits and soil properties, the first RDA axis accounted for 70.99 and 71.09% of the variation in 0–40 and 40–80 cm of soil properties. Relative importance analysis found that in the 0–40 cm soil layer, leaf traits variations were mainly influenced by soil moisture (SWC), HCO3− and CO32− ions content, while leaf traits variations in the 40–80 cm soil layer were mainly influenced by HCO3− and SO42−. L.ruthenicum has a foliar resource acquisition method and a resource conservation trade-off with a flexible life history strategy in habitats with drought and salinity stress. In the shallow soil layers, water affects leaf traits variation greater than salt, and in both shallow and deep soil layers, HCO3− plays a dominant role on leaf traits. This study provides insights into the adversity adaptation strategies of desert plants and the conservation and restoration of arid-saline ecosystems.

Desert plants are zonal vegetation with unique functional traits and resource trade-offs in arid areas. The trade-off relationship among functional traits and adversity strategies of desert plants play a key role in their community construction. We investigated 16 leaf functional traits of the dominant desert plants, including15 shrubs and 11 herbs, in the Hexi Corridor from southeast to northwest, and analyzed the variation characteristics of traits, trade-off relationship among traits and their responses to soil properties at the regional scale. The results showed that bound water (BW), leaf thickness (LT), and carbon phosphorus ratio (C:P) but total water content (TWC), free water (FW), specific leaf volume (SLV), and specific leaf area (SLA) under shrubs were significantly higher and significantly lower than under herbs, respectively; shrubs' leaf traits BW and FW ratio (BW:FW), phosphorus content (P), C:P, nitrogen and phosphorus ratio (N:P) had great coefficient of variation, while herbs' leaf traits BW and N:P had great coefficient of variation. Trade-off among the measured traits was diverse. The TWC, BW, SLV, leaf succulence (Suc), SLA, leaf dry matter content (LDMC) and LT are prominent traits that represent and reflect desert plants under adversity stress. Soil organic carbon (SOC), elevation, pH, soil water content (SW) and sand (0.5-0.25 mm) are important factors influencing the changes of shrubs' leaf traits, while available phosphorus (AP), SOC, silt (0.02-0.002 mm), sand (0.10-0.05 mm) and clay (<0.002 mm) are dominant factors affecting the changes of herbs' leaf traits. The results from the present study can provide theoretical support for the maintenance, management and stability of the Hexi Corridor' ecosystems.

The Tibetan Plateau is highly sensitive to elevated temperatures and has experienced significant climate warming in the last decades. While climate warming is known to greatly impact alpine ecosystems, the gas exchange responses at the leaf and community levels to climate warming in alpine meadow ecosystems remain unclear. In this study, the alpine grass, Elymus nutans, and forb, Potentilla anserina, were grown in open-top chambers (OTCs) for 3 consecutive years to evaluate their response to warming. Gas exchange measurements were used to assess the effects of in-situ warming on leaf- and community-level photosynthetic carbon assimilation based on leaf photosynthetic physiological parameters. We introduced a means of up-scaling photosynthetic measurements from the leaf level to the community level based on six easily measurable parameters, including leaf net photosynthetic rate, fresh leaf mass per unit leaf area, fresh weight of all plant leaves in the community, the percentage of healthy leaves, the percentage of received effective light by leaves in the community, and community coverage. The community-level photosynthetic carbon assimilation and productivity all increased with warming, and the net photosynthetic rate at the leaf level was significantly higher than at the community level. Under elevated temperature, the net photosynthetic rate of E. nutans decreased, while that of P. anserina increased. These results indicated that climate warming may significantly influence plant carbon assimilation, which could alter alpine meadow community composition in the future.

土壤水分和氮肥是影响荒漠绿洲区作物生长和种内关系的主要因素.为明确不同施氮量下干旱胁迫对棉花产量以及种内关系的影响,本研究以集群栽培(1穴3株)下棉花为研究对象,设置3种施氮量[300 kg(N)·hm-2、225 kg(N)·hm-2、150 kg(N)·hm-2]和3种水分处理(正常水分、中度干旱胁迫、重度干旱胁迫),测定了不同处理下棉花的生长指标和棉花产量,分析了不同处理下棉花种内关系的变化.结果表明:1)同一施肥条件下,2016年和2017年棉花株高在重度干旱胁迫下显著降低,而茎粗随干旱胁迫加剧显著降低,但叶面积随干旱胁迫加剧却有所增加,且在中度干旱胁迫下的叶面积最大.2)同一施肥条件下,与正常水分相比,中度和重度干旱胁迫下棉花的茎秆生物量均显著下降;叶片生物量和籽棉产量在中度干旱胁迫下最高,在重度干旱胁迫下却降低.3)在当地施氮量300 kg·hm-2下,随着干旱胁迫的加剧,相对邻体效应(relative neighbor effect,RNE)数值从正值变为负值;在氮肥减少处理(225 kg·hm-2)下,随着干旱胁迫的加剧,RNE数值先升高后降低,而在施氮量为150 kg·hm-2处理下,RNE数值随着干旱的加剧逐渐降低,且均为负值.总之,在当地施氮量和中度干旱胁迫下棉花能够获得较高的籽棉产量,且在此处理下棉花的种内关系为助长关系;其他处理均降低了棉花的产量, 并使得棉花的种内关系转变为竞争关系.

Abstract Evaluating how decomposition rates and litter nutrient release of different litter types respond to changes in water conditions is crucial for understanding global carbon and nutrient cycling. However, it is unclear how decreasing water affects litter mixture interactions for the maize–poplar system in arid regions. Here, the responses of the litter decomposition process and litter mixture interactions in the agroforestry system to changes in water conditions (control, light drought, and moderate drought) were tested. Moderate drought significantly decreased the decomposition rate for poplar leaf and mixed litters, and decomposition rate was significantly reduced for maize straw litter in light and moderate drought stress. The mass loss rates of maize straw and mixed litters were significantly higher than that of the poplar leaf litter under drought conditions, but there was no significant difference among the three litter types in the control. There was no interaction between mass loss of the mixed litter in the control and light drought conditions, and the litter mixture interaction showed nonadditive synergistic interactions under moderate drought. In terms of nutrient release, there was also no interaction between litter mixture with nitrogen and carbon, but there was antagonistic interaction with potassium release under the light drought condition. Our results demonstrate that drought conditions can lead to decreasing decomposition rate and strong changes in the litter mixture interactions from additive effects to nonadditive synergistic effects in moderate drought. Moreover, light drought changed the mixture interaction from an additive effect to an antagonistic interaction for potassium release.

严酷荒漠生境下C3植物红砂(Reaumuria songarica)和C4植物珍珠猪毛菜(Salsola passerina)形成单生和联生并存的混生群落.选择干旱内陆黑河流域山前典型混生区为研究对象,比较单生、联生荒漠植物叶片功能性状特征,分析其根际土壤微生物多样性结构,揭示混生植物叶片功能性状与其根际微生物组成之间的相互关系.结果显示:C4珍珠猪毛菜与C3红砂种间联生显著(P<0.05)降低了两种植物的叶水势(LWP),并且联生珍珠猪毛菜与单生相比,相对含水量(RWC)也显著(P<0.05)下降;对C4珍珠猪毛菜和C3红砂根际微生物多样性的分析发现,种间联生并未显著改变优势(相对丰度≥1％)根际微生物(细菌、真菌)门水平上的相对丰度,但是同时提高了两种植物根际土壤细菌的数量(OTUs、Chao1指数)和多样性(Shannon指数、Simpson指数);冗余分析(RDA)表明,C4珍珠猪毛菜和C3红砂根际细菌和真菌的丰富度指数(Chao1)、均匀度指数(Shannon)均与叶水势(LWP)呈显著(P<0.05)负相关关系;比叶面积(SLA)、比叶体积(SLV)主要受真菌丰富度指数(Chao1)的影响,与其呈显著(P<0.05)负相关关系.C4珍珠猪毛菜与C3红砂的种间联生,导致了根际微生物丰富度与均匀度的提高并影响植物叶片功能性状发生改变,增强了C4珍珠猪毛菜和C3红砂对干旱荒漠有限水分和资源的获取能力、互补特征.

青藏高原的格桑花是什么植物或者说是什么植物的花,存在广泛争议,困扰着想一探究竟的人们.格桑花作为一种精神存在于藏族百姓心中,是他们追求幸福吉祥和美好生活的情感象征,是重要的雪域文化标识,认识熟知并开发利用好它,将有助于推动藏区生态、文化和产业振兴.金露梅是青藏高原分布最广的树木,按集生羽状复叶小叶数可分为5叶金露梅和7叶金露梅,《中国植物志》对它们的记载分别是金露梅(Potentilla fru-ticosa L.)和小叶金露梅(P.parvifolia Fisch.).通过对青藏高原植被和历史文化景观考察,结合当地藏民描述及地方传说,本研究认为格桑花就是金露梅,其分布海拔可以拓展到5200 m的高寒恶劣环境.金露梅生性强健,耐寒、耐旱、耐瘠薄、耐强光,象征着藏族同胞刚毅、坚强、勤劳质朴、不畏严寒、生命力顽强的品格.