Functional traits of grasses growing in open and shaded habitats

The amount of light available for photosynthesis is a key environmental factor that shapes the form and function of plants. Several plant traits affect the manner in which different species fix carbon during vegetative growth. Under the hypothesis that grasses respond to environmental selective pressures, we analyzed the differences in certain leaf, culm, and regenerative traits of 283 native Uruguayan grasses growing in open (grassland) and shaded (forest) habitats. In order to differentiate the phylogenetic effects from the adaptive changes to current local conditions, we used phylogenetically controlled comparative analysis. We found that the divergence of grass species between grasslands and forests was accompanied by changes in leaf traits. Narrow and filiform blades (higher length/width ratio) were favored in species growing in grasslands, while wider and oval blades were favored in species growing in forests. The response of the leaf blades in forests was probably directed towards maximizing light interception, while in grasslands could be linked to the loss of water and heat. In contrast, we found that neither the culm nor the caryopsis length exhibited significant evolutionary changes associated with open or shaded habitats. Our results highlight the functional significance and adaptive value of the width and shape of the grass blades to the current environment.     

Grazing effects on herbage nutritive values depend on precipitation and growing season in Inner Mongolian grassland

Aims Grasslands are widely used for production of livestock, which depend on the nutritive value of herbage species. However, there are still large uncertainties as to how grazing, precipitation and growing season interactively affect herbage nutritive value.Methods Here, based on a grazing experiment with seven grazing intensities in an Inner Mongolian grassland since the year 2005, we analysed nutritive value of four dominant grass species from June to September in both a relatively wetter year (2008) and a drier year (2010). Herbage with high nutritive value is characterized by high concentration of crude protein, high concentration of cellulase digestible organic matter and low concentration of neutral detergent fibre.Important findings We found that (i) grazing significantly increased the nutritive value of Leymus chinensis, Agropyron michnoi and Cleistogenes squarrosa but had minor effects on the nutritive value of Stipa grandis. (ii) For all species, nutritive values were greater in the wetter year than in the drier year and were greatest in the early growing season (June) and lowest at the end of the growing season (September). Inter-annual and inter-seasonal variations in nutritive value were much greater for L. chinensis and A. michnoi than for C. squarrosa and S. grandis, suggesting higher water use efficiency for the latter two species. (iii) Grazing significantly decreased the drought resistance of three species, but not of S. grandis. (iv) Grazing significantly increased inter-month variation in nutritive value for L. chinensis and A. michnoi but had relatively minor or no effects on that of C. squarrosa and S. grandis. Therefore, grazing effects on species nutritive values showed strong inter-annual and seasonal patterns, and species-specific responses might be related to species traits (i.e. water use efficiency, digestibility). Our results have important implications for ecosystem management of arid and semi-arid grasslands under intense grazing and global climatic change.     

Intraspecific changes in plant morphology,associated with grazing,and effects on litter quality,carbon and nutrient dynamics during decomposition

Abstract: Continuous biomass removal by grazing usually changes the resource allocation pattern of plants. These changes often increase resistance to tissue removal and produce individuals with different morphometric traits, such as root to shoot or blade to sheath ratios. Shifts in morphometric traits, in turn, may alter nutrient cycling through changes in the average quality of litter that decomposes in soil. Previous work has shown that Paspalum dilatatum, a native grass from the Pampas grasslands, which inhabits a vast area and supports a wide range of grazing conditions, increases its blade to sheath ratio under continuous grazing with respect to ungrazed conditions. Here, we explored the consequences of these changes apparently associated with grazing regime on litter quality and nutrient dynamics during litter breakdown in soil. We separately analysed litter quality of blades and sheaths of P. dilatatum and determined under controlled conditions their decomposition and nutrient release kinetics over a maximum period of 1 year. We also studied the mineral nitrogen contents in soil amended with each litter type. Blade quality was significantly higher than sheath quality, nitrogen concentrations of blades and sheaths were approximately 1% and 0.6%, respectively, and lignin to nitrogen ratios were approximately 5 and 11 for blades and sheaths, respectively. Phosphorus concentration, however, was similar in both litter types. Blades decomposed 10% faster than sheaths, released 20% more nitrogen and released 15% more phosphorus than sheaths during the last half of the incubation period. During the first 3 months, the soil nitrogen content of litter‐amended incubations indicated immobilization with respect to non‐amended control; however, later blade incubations mineralized nitrogen, whereas sheath incubations continued immobilizing it. Results revealed that grazing potentially accelerates nutrient cycling during decomposition by increasing the blade to sheath ratio of P. dilatatum individuals, and suggest that this may be an important mechanism underlying grazing impact on nutrient cycling.     

Temporal trends in species composition and plant traits in natural grasslands of Uruguay

Abstract. We report the successional trends of the major life‐forms (graminoids and forbs) in natural grasslands of Uruguay over a 9‐yr period after the removal of domestic herbivores. For the whole community, species richness and diversity decreased over the successional period. In graminoids we observed clear temporal trajectories in floristic composition; the rate of floristic change decreased with time and was associated with a shift in plant traits. The exclusion of large herbivores promoted erect and tall grasses with narrow leaves and greater seed length, vegetative growth constrained to the cool season and increased frequency of annual species. Forbs did not show a clear temporal trend in species composition, but there was, nevertheless, a plot‐specific species turnover of this functional group that was reflected in their attributes. Species spreading by means of rhizomes, with vegetative growth restricted to the warm season. Species with larger seeds increased under grazing exclusion, as did annual and nitrogen‐fixing forbs. The floristic changes induced by cattle exclusion occurred early in the succession. This early high rate of change has practical implications for management and conservation programs of the natural grasslands of Uruguay. Additionally, the shift in plant traits may be helpful in devising simple indicators of grazing impact.     

Impact of grazing on germination trait selection in an alpine grassland on the Tibet Plateau

放牧对青藏高原高寒草地种子萌发性状选择的影响 以前的研究表明放牧能够引起草地生物与非生物环境的显著变化,但这种变化影响草地群落对种子萌发特征的选择机制尚不清楚。因此,我们旨在回答：放牧是否对草地群落中萌发特征的组成和多样性产生显著影响。我们在实验室检测了研究草地群落内主要物种种子的萌发特性,并比较了这些植物在放牧和非放牧草地上的表现。在此基础上,比较了放牧草地和非放牧草地的各萌发性状的群落加权平均值和萌发性状多样性,从而了解放牧草地和非放牧草地是否存在不同的萌发性状结构。研究结果表明,在物种水平上,放牧和非放牧草地各物种的多度变化与物种的萌发性状无显著关系。但在群落水平上,与非放牧草地相比,放牧草地的物种普遍具有较高的种子萌发率;放牧草地种子萌发对变温的正响应显著大于非放牧草地,而且放牧草地种子萌发温度生态位宽度小于非放牧草地。与非放牧草地相比,放牧草地种子萌发性状多样性增加,萌发性状均匀度降低。放牧可以改变微生境,从而通过环境过滤改变草地群落对萌发性状的选择,导致草地群落的萌发性状于放牧前后在群落水平上存 在显著差异。     

Root and leaf functional trait relations in Poaceae species: implications of differing resource-acquisition strategies

Aims Root systems play an essential role in grassland functioning in both acquisition and storage of resources. Nevertheless, root functional traits have not received as much attention as those measured on above-ground organs, and little is known about their relations. Our objectives were to test whether morphological and root system traits allowed identification of grass species' functional strategies and to determine whether a relation exists between above- and below-ground traits.Methods Functional traits of root tissues (specific root length, diameter, tissue density and nitrogen concentration), whole root systems (root mass, root length density, root mass percentage below a depth of 20cm and fine root %) and two major leaf traits (specific leaf area and leaf dry matter content) were determined under field conditions and their relations were analysed in eleven perennial temperate Poaceae species.Important findings Canonical correspondence analysis along Axis 1 revealed a gradient of species, from those with deep, dense and coarse root systems with a large root mass to those with shallow root systems, thin roots and high specific root length; this suggests strong correlations among root traits. Correlations between specific root length and specific leaf area reveal two groups of species, which probably indicates different drought-tolerance capacities. Root trait syndromes enable ranking grasses along a gradient from conservative-strategy species (from stressful habitats), which display a deep and coarse root system, to acquisitive species (from rich and moist meadows), which display a shallow and thin root system. Although both types display similar above-ground strategies, drought-tolerant species have lower specific root lengths than drought-sensitive species, revealing more conservative root strategies.     

退化草地物种种内和种间功能性状变异对放牧的响应

研究草地植物功能性状变异对放牧干扰的响应机制,有助于解析草地生态系统群落构建和功能多样性维持机制及植物对环境的适应及权衡策略。以科尔沁沙地退化草地为对象,研究围封和放牧草地物种多种功能性状(植株高度、根系长度、叶面积、根面积、叶片干物质含量、地上干物质含量、根系干物质含量、比叶面积、比根长和根冠比)变异特征及其对放牧干扰的响应机制。结果表明: 退化草地物种种间性状变异明显高于种内变异,种间性状变异对总体变异的贡献率占比高达70.2%～95.1%,而种内变异仅为4.9%～29.8%,但群落构建中物种的种内变异仍不可忽视。放牧草地物种种间性状变异低于围封草地,且放牧草地种内变异增加而种间变异减小。放牧导致不耐牧的优良禾本科牧草叶面积和叶片干物质含量下降而比根长增加,但耐牧的杂类草则通过增加叶面积和叶片干物质含量并降低比根长来提高在群落中的优势地位。退化草地对放牧响应较为敏感的功能性状有叶面积、叶片干物质含量、比根长和比叶面积。植物叶片性状和根系性状自身及彼此间均呈显著正相关,但放牧会增强根系性状的协同效应而减弱叶片性状的协同效应。说明放牧会驱动植物个体和种群功能性状权衡策略发生改变,进而起到调控植物群落结构和功能的作用。     

Grazing Lawns in Terai Grasslands,Royal Bardia National Park,Nepal1

We compared the community structure, nutritive quality, and aboveground biomass of grazing lawns (patches of shortgrass communities) to neighboring grasslands in the Terai of western Nepal. Grazing lawns differed from the adjacent grasslands in species composition and community structure. Species diversity and species richness were higher on grazing lawns (H = 1.60, S = 20.93) than the grasslands (H = 0.97, S = 8.97). Fencing that excluded grazers for 150 days made areas of grazing lawns indistinguishable from neighboring grasslands in terms of plant height and biomass. Growing shoots of forage from grazing lawns had higher digestibility, crude protein, and sodium than forage from the grasslands. Grazing lawns appear to be maintained by continuous grazing and are enriched by deposition of urine, dung, and by certain plant species not found in the the adjacent grasslands.     

Importance of grazing and soil acidity for plant community composition and trait characterisation in coastal dune grasslands

Question: Does grazing by large herbivores affect species composition or community‐wide variation in plant functional traits? Location: Dune grasslands at the Belgian coast. Methods: Plant cover and soil data were collected in 146 plots that were randomly selected at 26 grazed and ungrazed grassland sites. Plant community composition was assessed by Detrended Correspondence Analysis and mean values of plant trait categories were calculated across the plots. Results: Differentiation of plant composition and community‐wide plant trait characteristics was largely determined by grazing, soil acidity and their interaction. In ungrazed situations, a clear floristic distinction appears between acidic (non‐calcareous) and alkaline (calcareous) grasslands. In grazed situations, these floristic differences largely disappeared, indicating that grazing results in a decrease of natural variation in species composition. At higher soil pH, a larger difference in plant community composition and community‐wide plant traits was observed between grazed and ungrazed plots. In ungrazed situations, shifts in plant functional traits along the acidity gradient were observed. Conclusions: Grazing is responsible for shifts in plant community composition, and hence a decrease in plant diversity among grasslands at opposing acidity conditions in coastal dune grasslands. Therefore, care should be taken when introducing grazing as a system approach for nature conservation in dune grasslands as it may eliminate part of the natural variation in plant diversity along existing abiotic gradients.     

Effect of fencing and grazing on a Kobresia-dominated meadow in the Qinghai-Tibetan Plateau

Grazing is one of the most important factors influencing community structure and productivity in natural grasslands. Fencing to exclude grazers is one of the main management practices used to protect grasslands. Can fencing improve grassland community status by restraining grazing? We conducted a field community study and indoor soil analyses to determine the long-term effects of fencing and grazing on the above-ground community and soil in a Kobresia-dominated meadow in the Qinghai-Tibetan Plateau, NW China. Our results showed that fencing significantly improved above-ground vegetation productivity but reduced plant density and species diversity. Long-term fencing favored the improvement of forage grass functional groups and restrained the development noxious weed functional groups. There were significant positive effects of fencing on below-ground organic matter, total nitrogen, available nitrogen, total phosphorus and available phosphorus. The productivity of grazed meadow showed a weak decrease over time. There were long-term decreasing trends for plant density both in fenced and grazed meadows. Our study suggests that grazing can be considered as a useful management practice to improve species diversity and plant density in long-term fenced grasslands and that periodic grazing and fencing is beneficial in grassland management.     

Responses of savanna lawn and bunch grasses to water limitation

The grass layer of African savannas consists of two main vegetation types: grazing lawns, dominated by short, mostly clonally reproducing grasses, and bunch grasslands, dominated by tall bunch grasses. This patchy distribution of vegetation types is mostly created by large herbivores, which selectively feed on the more nutritious lawn grass species. Besides grazing, herbivores trample the soil, thereby causing soil compaction, with possible consequences for water infiltration. This raises two questions: (i) is water more limiting in grazing lawns than in bunch grasslands and (ii) are lawn grasses more drought tolerant than bunch grasses? To study these questions, we compared drought conditions in both lawn and bunch grasslands in a South African savanna. Additionally, in a climate room, we compared the performance of three lawn and three bunch grass species under a control and a water limitation treatment. Thirdly, we investigated whether there are differences between lawn and bunch grasses in traits related to drought tolerance. Our results show that despite large differences in water availability in the field, lawn and bunch grasses did not differ in their growth response to drought. Drought reduced growth of both growth forms equally. However, we found strong intrinsic trait differences between growth forms, with lawn grasses having higher specific root length and relative growth rate and bunch grasses having a higher root:shoot ratio. These results suggest that after drought-induced plant death, lawn grasses might be more capable of recolonizing patches of bare soil.     

Dynamics of grazing lawn formation: an experimental test of the role of scale‐dependent processes

Grazing lawns are characteristic for African savanna grasslands, standing out as intensely grazed patches of stoloniferous grazing‐tolerant grass species. Grazing lawn development has been associated with grazing and increased nutrient input by large migratory herds. However, we argue that in systems without mass migrations disturbances, other than direct grazing, drive lawn development. Such disturbances, e.g. termite activity or megaherbivore middens, also increase nutrient input and keep the bunch vegetation down for a prolonged time period. However, field observations show that not all such disturbances lead to grazing lawns. We hypothesize that the initial disturbance has to be of a minimal threshold spatial scale, for grazing intensity to be high enough to induce lawn formation. We experimentally tested this idea in natural tall savanna grassland. We mowed different‐sized plots to simulate initial disturbances of different scales (six times during one year) and applied fertilizer to half of the plots during two years to simulate increased nutrient input by herbivores or termite activity. Allowing grazing by naturally occurring herbivores, we followed the vegetation development over more than three years. Grazing kept bunch grass short in coarser, fertilized plots, while grasses grew out toward their initial height in fine‐scale and unfertilized plots. Moreover, lawn grasses strongly increased in cover in plots with an increased nutrient input but only after coarser scale disturbance. These results support our hypothesis that an increased nutrient input in combination with grazing indeed induces grazing lawn formation, but only above a threshold scale of the initial disturbance. Our results provide an alternative mechanism for the development of grazing lawns in systems that lack mass migrating herds. Moreover, it gives a new spatial dimension to the processes behind grazing lawn development, and hence help to understand how herbivores might create and maintain spatial heterogeneity in grassland systems.     

天山云杉种子形态性状的地理变异

以新疆天山山脉从西到东不同经度3个地点(昭苏、天池和奇台)的天山云杉林为对象,沿海拔梯度采集不同地点的天山云杉球果,分析其种子性状(种鳞长、种鳞宽、种鳞长宽比、种翅长、种翅宽、种翅长宽比、种子长、种子宽和种子长宽比)的变化.结果表明: 随海拔的升高,天山云杉种子性状(种子宽除外)总体呈现下降的趋势;除种翅宽、种子宽和种子长宽比与海拔的相关性不显著外,种子其他性状与海拔均呈显著负相关;种鳞长、种鳞宽、种鳞长宽比与经度呈现显著正相关;种鳞长、种鳞长宽比、种翅长宽比与坡度呈显著负相关;除种翅宽外,种子其他性状与坡向相关性均不显著.海拔是影响天山云杉种子的种鳞长、种鳞长宽比和种翅长宽比的主要因子.     

Variation of morphological and chemical traits in sexes of the dioecious perennial grass Poa ligularis in relation to shrub cover and aridity in Patagonian ecosystems

Sexes of dioecious species may have dimorphic responses to environmental variation due to differences in resource requirements and reproductive costs. We analyzed the effect of aridity/relative shrub cover, and vicinity to shrub patches on morpho-chemical traits of sexes of the dioecious perennial grass Poa ligularis in patchy arid ecosystems in northern-central Patagonia. We hypothesized that sexes of P. ligularis have dimorphic responses in morpho-chemical traits in relation to the environmental variation induced by aridity/relative shrub cover and vicinity to shrub patches. We selected seven sites across a gradient of increasing aridity and relative shrub cover. We randomly collected 5–10 P. ligularis plants per site registering the sex (female or male) and location with respect to shrub patches (shrub patch or inter-patch). For each plant, we assessed morpho-chemical traits (height of the vegetative tillers, length/dry weight/area of blades, specific blade area, nitrogen and soluble phenol concentration in blades). Sexes showed dimorphic responses in height of vegetative tillers, blade length, and blade area with respect to vicinity to shrub patches; and in variation of soluble phenolics in blades in relation to aridity/relative shrub cover. Responses in both sexes were opposite to those expected by aridity, highlighting the role of favorable environments induced by shrub canopies on dimorphic responses of sexes of P. ligularis. Resource-rich microsites associated with shrub canopies promoted increased plant performance of females with high reproductive costs while resource-poor open areas, favorable for pollen dispersal, induced improved chemical defenses of males. These results are consistent with the resource availability hypothesis.     

Response of Polygonum viviparum species and community level to long-term livestock grazing in alpine shrub meadow in Qinghai-Tibet Plateau

Grazing by domestic herbivores is generally recognized as a major ecological factor and an important evolutionary force in grasslands. Grazing has both extensive and profound effects on individual plants and communities. We investigated the response patterns of Polygonum viviparum species and the species diversity of an alpine shrub meadow in response to long-term livestock grazing by a field manipulative experiment controlling livestock numbers on the Qinghai-Tibet Plateau in China. Here, we hypothesize that within a range of grazing pressure, grazing can alter relative allocation to different plant parts without changing total biomass for some plant species if there is life history trade-offs between plant traits. The same type of communities exposed to different grazing pressures may only alter relative species' abundances or species composition and not vary species diversity because plant species differ in resistant capability to herbivory. The results show that plant height and biomass of different organs differed among grazing treatments but total biomass remained constant. Biomass allocation and absolute investments to both reproduction and growth decreased and to belowground storage increased with increased grazing pressure, indicating the increasing in storage function was attained at a cost of reducing reproduction of bulbils and represented an optimal allocation and an adaptive response of the species to long-term aboveground damage. Moreover, our results showed multiform response types for either species groups or single species along the gradient of grazing Intensity. Heavy grazing caused a 13.2％ increase in species richness. There was difference in species composition of about 18％--20％ among grazing treatment. Shannon-Wiener (H') diversity index and species evenness (E) index did not differ among grazing treatments. These results support our hypothesis.     

Fungal endophyte diversity in tundra grasses increases by grazing

Fungal endophytes are species rich and ubiquitous, yet, apart from the genus Epichloë, their ecology is largely unknown. Here we explore how herbivores affect the diversity of fungal endophytes in tundra grasslands. We assess both hyphal morphological and taxonomic diversity in grass individuals.By microscopic examination we identified endophytes to be present in all sampled grass individuals whereas identification to taxonomic units were only achieved in a subset of the individuals using laser micro dissection pressure catapulting and culturing for endophyte isolation. Hyphal morphological diversity was significantly higher in grasses exposed to grazing, along with 45 % more taxonomic units achieved.Our results suggest that grazing is an important mediator of fungal endophyte diversity in tundra grasslands. Furthermore, we suggest laser dissection of stained endophytes as a method for further exploring the ecological role of fungal endophytes.     

中国传统大菊叶片形态的数量化定义与分类

中国传统大菊品种叶片形态变异丰富,然而至今仍未对其进行科学的定义和分类,无法有效利用这些形态性状进行品种鉴定和叶形遗传解析。利用数量化分析方法对植物形态进行定义和分类,是植物性状遗传解析的前提。对436个中国传统大菊品种的24个叶形性状进行重新定义及观测,通过相关性分析确定了8个相对独立的性状,用变异系数及主成分分析等...     

Grazing effect on grasslands escalated by abnormal precipitations in Inner Mongolia

Grazing effects on arid and semi‐arid grasslands can be constrained by aridity. Plant functional groups (PFGs) are the most basic component of community structure (CS) and biodiversity & ecosystem function (BEF). They have been suggested as identity‐dependent in quantifying the response to grazing intensity and drought severity. Here, we examine how the relationships among PFGs, CS, BEF, and grazing intensity are driven by climatic drought. We conducted a manipulative experiment with three grazing intensities in 2012 (nondrought year) and 2013 (drought year). We classified 62 herbaceous plants into four functional groups based on their life forms. We used the relative species abundance of PFGs to quantify the effects of grazing and drought, and to explore the mechanisms for the pathway correlations using structural equation models (SEM) among PFGs, CS, and BEF directly or indirectly. Grazers consistently favored the perennial forbs (e.g., palatable or nutritious plants), decreasing the plants’ relative abundance by 23%–38%. Drought decreased the relative abundance of ephemeral plants by 42 ± 13%; and increased perennial forbs by 20 ± 7% and graminoids by 80 ± 31%. SEM confirmed that annuals and biennials had negative correlations with the other three PFGs, with perennial bunchgrasses facilitated by perennial rhizome grass. Moreover, the contributions of grazing to community structure (i.e., canopy height) were 1.6–6.1 times those from drought, whereas drought effect on community species richness was 3.6 times of the grazing treatment. Lastly, the interactive effects of grazing and drought on BEF were greater than either alone; particularly, drought escalated grazing damage on primary production. Synthesis. The responses of PFGs, CS, and BEF to grazing and drought were identity‐dependent, suggesting that grazing and drought regulation of plant functional groups might be a way to shape ecosystem structure and function in grasslands.     

Functional traits of tree species with phylogenetic signal co-vary with environmental niches in two large forest dynamics plots

Aims While using phylogenetic and functional approaches to test the mechanisms of community assembly, functional traits often act as the proxy of niches. However, there is little detailed knowledge regarding the correlation between functional traits of tree species and their niches in local communities. We suggest that the co-varying correlation between functional traits and niches should be the premise for using phylogenetic and functional approaches to test mechanisms of community assembly. Using functional traits, phylogenetic and environmental data, this study aims to answer the questions: (i) within local communities, do functional traits of co-occurring species co-vary with their environmental niches at the species level? and (ii) what is the key ecological process underlying community assembly in Xishuangbanna and Ailaoshan forest dynamic plots (FDPs)?Methods We measured seven functional traits of 229 and 36 common species in Xishuangbanna and Ailaoshan FDPs in tropical and subtropical China, respectively. We also quantified the environmental niches for these species based on conditional probability. We then analyzed the correlations between functional traits and environmental niches using phylogenetic independent contrasts. After examining phylogenetic signals of functional traits using Pagel's λ, we quantified the phylogenetic and functional dispersion along environmental gradients within local tree communities.Important findings For target species, functional traits do co-vary with environmental niches at the species level in both of the FDPs, supporting that functional traits can be used as a proxy for local-scale environmental niches. Functional traits show significant phylogenetic signals in both of the FDPs. We found that the phylogenetic and functional dispersion were significantly clustered along topographical gradients in the Ailaoshan FDP but overdispersion in the Xishuangbanna FDP. These patterns of phylogenetic and functional dispersion suggest that environmental filtering plays a key role in structuring local tree assemblages in Ailaoshan FDP, while competition exclusion plays a key role in Xishuangbanna FDP.     

Ecosystem changes associated with grazing in subhumid South American grasslands

Question: What are the changes in vegetation structure, soil attributes and mesofauna associated with grazing in mesic grasslands? Location: Southern Campos of the Río de la Plata grasslands, in south‐central Uruguay. Methods: We surveyed seven continuously grazed and ungrazed paired plots. Plant and litter cover were recorded on three 5‐m interception lines placed parallel to the fence in each plot. We extracted soil fauna from a 10 cm deep composite sample and analysed the oribatids. Soil attributes included bulk density, water content, organic carbon (in particulate and mineral associated organic matter) and nitrogen content and root biomass at different depths. Changes in floristic, Plant Functional Types and mesofauna composition were analysed by Non‐metric Multidimensional Scaling. Results: Species number was lower in ungrazed than in grazed plots. Of 105 species in grazed plots only three were exotics. Shrub and litter cover were significantly higher inside the exclosures, while the cover of Cyperaceae‐Juncaceae was lower. Grazing treatments differed significantly in plant and oribatid species composition. Grazing exclusion significantly reduced soil bulk density and increased soil water content. Carbon content in particulate organic matter was lower in the upper soil of ungrazed sites, but deeper in the profile, grazing exclosures had 8% more carbon in the mineral associated organic matter. Conclusions Our results generally agree with previous studies but deviate from the results of previous analyses in (1) the increase of shrub cover in ungrazed sites; (2) the redistribution of the soil organic carbon in the profile and (3) the low invasibility of the prairies regardless of grazing regime.