内蒙古典型草原区3种不同草地利用模式下植物功能群及其多样性的变化

以呼伦贝尔草原辉河国家级自然保护区草原群落为研究对象, 选取3块生境条件基本相同的样地(250 m × 250 m) ——放牧场、割草场及公共草场, 每块样地设置3条样带, 每条样带上设置8个样方(1 m × 1 m), 研究了不同草地利用模式下草原群落的物种组成、生物多样性及群落的功能群特征。结果表明: 在放牧场、割草场和公共草场3种不同利用模式下, 植物功能群结构及其多样性发生了变化。灌木、半灌木的累积优势度在各利用模式间差异显著( p< 0.05), 在割草场中最高; 多年生禾草的累积优势度在各利用模式间差异显著(p< 0.05); 一、二年生草本的累积优势度在各利用模式间差异显著(p< 0.05)。旱生植物功能群在公共草场中所占比例最高, 为50%; 中旱生植物在割草场中的百分比最低, 为19%, 且在各利用模式间差异显著(p< 0.05); 各利用模式下, 灌木、半灌木功能群生物量均较低; 随着割草场、公共草场及放牧场3种草地利用模式下利用强度的增加, 多年生禾草和多年生杂类草两大功能群的生物量递减, 而一、二年生草本功能群生物量递增。草地利用强度的增加, 使得草地植物群落结构简单、脆弱。丰富度指数和多样性指数在放牧场最低, 在割草场最高; 均匀度变化并不明显。割草场利用模式有助于改善草原的健康状况, 而放牧场及公共草场利用模式均存在不同程度的过度放牧现象, 尤其是公共草场利用模式由于所有权不明确而缺乏有效的管理, 导致草原退化明显。     

内蒙古锡林河流域草原群落植物功能群组成沿水热梯度变化的样带研究

 用样带法调查了草原群落植物功能群组成沿水热梯度的变化。结果表明,随着海拔高度的降低,降水量的减少,热量和干燥度的增加,群落植物生活型功能群组成中,多年生杂类草的相对多度逐渐减少,而多年生丛生禾草的相对多度逐渐增加,多年生丛生禾草对多年生杂类草具有强烈的生态替代作用。在植物生态类群功能群组成中,中旱生植物的作用逐渐减弱,而旱生植物的作用显著增强。草地的利用方式对群落组成具有重要的影响,永久样地和割草场中不耐牧种的相对生物量显著地高于放牧场,而放牧场中耐牧种的相对生物量则显著地高于永久样地和割草场。受草地利用     

锡林河流域羊草草原植物种群和功能群的长期变异性及其对群落稳定性的影响

 分析了内蒙古锡林河流域羊草(Leymus chinensis)草原群落植物种群、功能群和群落生物量的长期变异性,以及植物功能群间的补偿作用对群落稳定性的影响,结果表明：从种群水平到功能群和群落水平,地上生物量的年度间变异性逐渐降低,而稳定性则逐渐增加。植物功能群组成对群落稳定性具有更强烈的影响,在植物生活型功能群组成中多年生根茎禾草与多年生丛生禾草和多年生杂类草功能群,在生物量的年度变化上具有补偿作用,在生态类群组成中,旱生植物与中旱生植物也具有补偿作用。植物种群多度的长期变异性可能依赖于物种对环境波动的敏感性和种间相互作用对环境波动的放大效应,生物多样性使物种对环境波动响应的多样性增加,并通过不同响应类型(功能群)间的补偿作用使群落稳定性增加。     

内蒙古高原针茅草原群落β多样性研究

用比较样地法调查了内蒙古高原 4类地带性针茅 (Stipa)草原群落的 β多样性特征 .结果表明 ,Whit tacker指数 βws与尺度有关 ,随取样面积的增加 ,βws逐渐降低 .取样面积相同时 ,4类群落的 βws比较接近 .各群落的Cody指数最初也随样方面积的扩大而增大 ,当样方面积扩大到一定尺度时 ,贝加尔针茅群落和大针茅群落为 >0 .5m2 ,克氏针茅群落和小针茅群落为 >2m2 ,Cody指数趋于稳定 .同一尺度下 ,贝加尔针茅群落的Cody指数最高 ,小针茅群落的Cody指数最低 .多数情况下 ,群落内样本间的间隔距离 ,对Cody指数有较大的影响 ;从贝加尔针茅群落到小针茅群落 ,植物生活型和生态类群功能群组成中 ,多年生丛生禾草与根茎禾草、多年生杂类草和中旱生植物的多样性显著降低 ,旱生植物多样性先增加 ,尔后到小针茅群落显著降低 .群落的植物种类组成表现出明显生态替代现象 ,不同群落间的Cody指数逐渐降低 ;贝加尔针茅群落与大针茅群落的Morisita Horn指数最高 ,达 0 .72 .克氏针茅群落与小针茅群落的相似系数最低 ,为 0 .42 .     

青藏高原高寒草甸植物群落结构和功能对氮、磷、钾添加的短期响应

对中国科学院海北高寒草甸生态系统定位站的矮嵩草草甸水肥样地进行了氮、磷、钾及其组合的施肥处理,研究了施肥对植物群落结构和功能的影响。结果表明:(1)施肥使矮嵩草草甸植物群落物种丰富度减少,不同施肥处理下物种丰富度大小分别为:对照钾磷氮氮磷磷钾氮钾氮磷钾。(2)在氮磷配合施肥处理下,矮嵩草草甸植物群落Shannon-Wiener指数显著高于对照,而其它施肥处理对Shannon-Wiener指数影响不显著。(3)在同一施肥处理下,禾草类和莎草类的重要值明显高于豆科和杂类草功能群,不同施肥处理使禾草、莎草、豆科植物的重要值增加,而杂类草重要值减少。(4)与对照相比,不同施肥(除钾外)处理可不同程度的增加植物群落的高度。(5)除钾、磷钾养分添加对矮嵩草草甸地上生物量的影响与对照差异不显著外,其它养分及其组合添加都极显著增加了群落地上生物量,且大小顺序依次为氮磷氮磷钾磷氮钾氮磷钾钾对照。(6)施用不同种类的肥料后,矮嵩草草甸各功能群地上生物量的比例变化明显,禾草和莎草的比例均增加,杂类草的比例减少,而豆科植物无规律性。(7)熵值法综合评价短期施肥处理对矮嵩草草甸群落的影响表明,氮磷、氮磷钾配合施肥是青藏高原高寒草甸最佳施肥选择。     

刈割留茬高度对大针茅草原群落结构及稳定性的影响

2014—2018年8月在内蒙古锡林郭勒盟毛登牧场大针茅典型草原,以围封为对照,设置2、5和8 cm 3个刈割留茬高度,研究刈割留茬高度对群落结构及稳定性的影响。结果表明: 群落中共出现15科23属27种植物;优势种为大针茅、知母、羊草及糙隐子草,累计相对重要值为76.1%。多年生杂类草15种,一、二年生植物5种,多年生丛生禾草和灌木半灌木植物各有3种,多年生根茎禾草有1种。大针茅等处于群落上层;知母、羊草等植物处于群落中层;糙隐子草、刺穗藜、猪毛菜等植物处于群落底层。刈割造成大针茅及多年生丛生禾草相对重要值降低,使得糙隐子草、刺穗藜、猪毛菜及一、二年生植物相对重要值增加。留茬2 cm降低羊草相对重要值,而留茬5、8 cm使其增加;留茬5 cm增加知母相对重要值,而留茬2、8 cm使其降低;留茬8 cm降低杂类草相对重要值,而留茬2、5 cm使其增加。物种及功能群多样性年度间差异显著。总体上,刈割对物种丰富度无显著影响,对其物种多样性影响较小,但对功能群多样性存在一定影响。表明在刈割过程中,群落各功能群存在一定的补偿作用,使得群落保持相对稳定。刈割使群落稳定性增加,留茬5和8 cm时群落稳定性较大;留茬5 cm时群落变异性较大,而留茬8 cm时最小。留茬8 cm时群落稳定性高且变异性小,能促进群落长期稳定。     

不同恢复措施对内蒙古乌拉特中旗荒漠草原植物群落的影响

处于干旱地区的内蒙古荒漠草原，在防风固沙、生物多样性保育等方面发挥着重要的生态功能。近年来由于人类活动的干扰及气候变化的影响，内蒙古荒漠草原生态系统发生了严重的退化。如何有效恢复荒漠草原的生态功能是当前亟待解决的问题，科学合理地进行人为定向培育是荒漠草原植物群落恢复与重建的重要措施。本研究以乌拉特中旗荒漠草原为对象，通过控制实验探讨了不同退化程度下植物群落结构及地上生物量对不同恢复措施的响应。结果表明：在重度退化的荒漠草原生态系统，短期封育提高了杂类草的相对盖度，使群落地上生物量增加2.11倍；添加有机肥提高了禾草物种丰富度，使群落地上生物量提高了3.97倍；补播显著提高了植物群落的盖度、密度，使群落地上生物量提高了9.76倍。在重度沙化区，补播显著提高了群落的盖度、密度、地上生物量，但对物种多样性无显著影响。在中度退化区，添加复合肥显著降低了短花针茅群落杂类草物种数，提高了禾草及植物群落的地上生物量；添加复合肥显著提高了柠条锦鸡儿-丛生禾草群落中禾草物种丰富度，但对植物群落盖度、密度及地上生物量无显著影响；喷施叶面肥显著降低了藏锦鸡儿-灌丛化禾草群落杂类草的盖度和密度，提高了禾草的地...     

去除干扰对内蒙古典型草原植物叶片功能属性的影响

以内蒙古典型草原为研究对象,选取放牧和割草、去除放牧、去除放牧和割草样地进行群落调查和叶片属性测量,比较分析各样地土壤性质、群落生产力及主要物种的比叶面积(SLA,Specific Leaf Area)、叶片干物质含量(LDMC,Leaf Dry Matter Content)、叶片氮含量(LNC,Leaf Nitrogen Concentration)在个体、功能群和群落水平对去除干扰的响应。结果表明,1)去除干扰处理在短期对土壤特性和群落生产力的影响不显著;2)多数物种在放牧和割草样地SLA较低,说明典型草原多数物种的SLA表现为放牧逃避;3)不同功能群植物叶片属性对去除干扰的响应不一致,去除放牧后,多年生杂类草的SLA和LDMC不受影响,但LNC变小;多年生禾草的SLA增加,而LDMC和LNC无显著变化。一年生植物在去除放牧和割草后,LNC显著增加。去除割草后,多年生禾草SLA减小,而多年生杂类草SLA、LNC增加,LDMC减小;4)在群落水平,放牧和割草样地由于较占优势的多年生禾草SLA较低,群落比叶面积最低,在去除放牧和割草样地,群落叶片氮含量显著增加;5)在内蒙古典型草原,LDMC能够很好地将多年生禾草和多年生杂类草区分,SLA在个体、功能群和群落水平均比LDMC敏感。     

内蒙古高原针茅草原植物多样性与植物功能群组成对群落初级生产力稳定性的影响

内蒙古高原4类地带性草原群落,贝加尔针茅（Stipa baicalensis Roshew.）群落、大针茅（S.grandis P.Smirn.）群落、克氏针茅（S.krylovii Roshev.）群落和小针茅（S.klemenzii Roshev.）群落初级生产力连续12年的定位研究结果表明,在气修波动下群落生产力及其稳定性与群落多样性特征的变化是一致的,从贝加尔针茅群落到小针茅群落。植物多样性显下降,群东中起重要作用的植物功能群的数量逐渐减少,群落初级生产力及其稳定性也逐渐降低。生活型功能群组成中,多年生丛生禾草、多年生根茎禾草与苔草和多年生杂类草功能群多样性与群落初级生产力稳定性极显地呈正相关。生态类群组成中,旱生植物和中旱生植物功能群多样性也与群落初级生产力稳定性极显地呈正相关,生态位互补效应（niche complementary effect）可能是高植物多样性群落具有高生产力的机制,而植物多样性对群落初级生产力稳定性的影响可能是通过不同功能群间的补偿作用来实现的。     

不同载畜率对荒漠草原群落结构和功能群生产力的影响

采用随机区组试验研究了内蒙古高原荒漠草原亚带短花针茅(S tip a brev if lora)草原群落不同载畜率对草原群落结构和功能群生产力的影响。结果表明:随着载畜率的增加,群落的植物种数逐渐减少,在每个载畜率水平下,冷蒿(A rtem isia f rig id a)占有绝对优势地位,优势度为35.66%~41.95%;群落的地上生物量随载畜率的增加而降低,各功能群地上生物量组成中,灌木类处于主体地位,分别占据了群落68%(CK)、77.40%(LG)、73.25%(M G)、76.91%(HG)的生物量;在植物生活型功能组成中,灌木类和杂类草、多年生丛生禾草和杂类草功能群,在生物量上具有生态互补效应(n iche com p lem en tary effect)。     

Reducing Competitive Suppression of a Rare Annual Forb by Restoring Native California Perennial Grasslands

Populations of the rare annual forb Amsinckia grandiflora may be declining because of competitive suppression by exotic annual grasses, and may perform better in a matrix of native perennial bunchgrasses. We conducted a field competition experiment in which Amsinckia seedlings were transplanted into forty 0.64‐m² experimental plots of exotic annual grassland or restored perennial grassland. The perennial grassland plots were restored using mature 3 cm‐diameter plants of the native perennial bunchgrass Poa secunda planted in three densities. The exotic annual grassland plots were established in four densities through manual removal of existing plants. Both grass types reduced soil water potential with increasing biomass, but this reduction was not significantly different between grass types. Both grass types significantly reduced the production of Amsinckia inflorescences. At low and intermediate densities (dry biomass per unit area of 20–80 g/m²), the exotic annual grasses reduced Amsinckia inflorescence number to a greater extent than did Poa, although at high densities (>90 g/m²) both grass types reduced the number of Amsinckia inflorescences to the same extent. The response of Amsinckia inflorescence number to Poa biomass was linear, whereas the same response to the annual grass biomass is logarithmic, and appeared to be related to graminoid cover. This may be because of the different growth forms exhibited by the two grass types. Results of this research suggest that restored native perennial grasslands at intermediate densities have a high habitat value for the potential establishment of the native annual A. grandiflora.     

内蒙古羊草群落、功能群、物种变化及其与气候的关系

基于1981-1994年内蒙古羊草草原的群落学调查数据和同期气象资料,分析了羊草草原群落、功能群与主要物种变化及其生物量与气候的关系.结果表明,1981-1994年5月羊草群落多样性指数、优势度指数、丰富度指数、群落高度、群落生物量的年际变异显著高于其他月,其中羊草群落生物量的变异性自5-9月依次降低,生物量和多样性不存在显著相关性.羊草群落、功能群、物种的年际变异依次增大;不同功能群中一二年生草本和中生植物的年际波动最大,不同物种间的均衡效应降低了群落的变异性.羊草群落生物量具有气候累积效应,主要受上年10月至当年12月的均温、4-8月降水、上年10月至当年8月累积降水的影响,表明羊草群落生物量变化由不同时段的水热因子协同作用决定.     

Repeated mowing to restore remnant native grasslands invaded by nonnative annual grasses: upsides and downsides above and below ground

California grasslands have been severely impacted by the invasion of nonnative annual grasses, which often limit restoration of this important ecosystem. In this study, we explored the use of mowing as a restoration tool for native perennial grasslands at the Santa Rosa Plateau Ecological Reserve in southern California. We sought to evaluate if, over time, mowing would reduce nonnative annual grass cover and benefit native species, especially the native bunchgrass Stipa pulchra. We hypothesized that repeated mowing, carefully timed to target nonnative annual grasses prior to seed maturation, would reduce nonnative seed inputs into the soil and eventually lead to diminished abundance of these species. We monitored vegetation in mowed and unmowed plots for 4 years, and conducted a seed bank study after 5 years to better understand the cumulative effects of mowing on native and nonnative seed inputs. Consistent with our hypotheses, we found that mowing successfully reduced nonnative annual grass cover and benefitted some native species, including S. pulchra. However, we also found that nonnative forb species showed progressive increases in mowed plots over time. We observed similar patterns of species composition in the soil seed bank. Together, these results suggest that mowing can be used to control nonnative annual grasses and increase the abundance of native bunchgrasses, but that this method may also have the unintended consequence of increasing nonnative forb species.     

Local soil,but not commercial AMF inoculum,increases native and non‐native grass growth at a mine restoration site

Soil communities are often degraded in mined sites, and facilitating the recovery of soil mutualists such as arbuscular mycorrhizal fungi (AMF) may assist with the restoration of native plants. At a grassland mine restoration site, I compared a commercial AMF inoculum with soil collected from beneath native grasses as a source of inoculum, as well as a control treatment. Field plots were broadcast‐inoculated and seeded with native grasses, and biomass of native and non‐native species was measured in three consecutive years. In addition, greenhouse‐grown seedlings of a native bunchgrass (Stipa pulchra) were inoculated with similar treatments, transplanted into the field, and assessed after 18 months. When broadcast inoculation was used, the local soil inoculum tended to increase non‐native grass biomass, and marginally decreased non‐native forb biomass in the second year of study, but did not significantly affect native grass biomass. Broadcast commercial inoculum had no detectable effects on biomass of any plant group. Stipa pulchra transplants had greater N content and mycorrhizal colonization, and marginally higher shoot mass and K content, when pre‐inoculated with local soil (relative to controls). Pre‐inoculation with commercial AMF increased AMF colonization of the S. pulchra transplants, but did not significantly affect biomass or nutrient content. The findings indicate that at this site, the use of local soil as an inoculum had greater effects on native and non‐native plants than the commercial product used. In order to substantially increase native grass performance, inoculation of transplanted plugs may be one potential strategy.     

Competitive interactions between the alien invasive annual grass <Emphasis Type="Italic">Avena fatua</Emphasis> and indigenous herbaceous plants in South African Renosterveld: the role of nitrogen enrichment

Nitrogen enrichment may play a role in successful invasion of indigenous South African mediterranean shrublands by alien invasive annual grasses. To test the hypothesis that an increase in nitrogen would result in a greater increase in biomass for an alien annual grass than for various indigenous plant functional groups, we conducted a field study in Western Cape Renosterveld shrubland fragments, surrounded by wheat or vinyards, to assess alien grass abundance in relation to soil nitrogen availability. Significant decreases in invasive annual grass Avena fatua cover and soil nitrogen were observed from the edges to the interior of Renosterveld habitat fragments and there was a significant positive relationship between Avena fatua cover and soil nitrogen. In addition, Avena fatua was grown in competition with three indigenous species of different functional types, an annual forb (Dimorphotheca pluvialis), a geophyte (Oxalis purpurea) and an indigenous perennial grass (Tribolium uniolae) at three concentrations of soil nitrogen in a pot experiment. Results revealed that the alien grass Avena fatua had significant increases in biomass when nitrogen was added, whereas the indigenous species did not. Alien grass competition significantly influenced performance of the annual forb and the indigenous grass but did not affect the geophyte. Results suggest the prioritization of hierarchical management options for the different functional groups in Renosterveld in response to invasive grasses. Nutrient enrichment through run off must be restricted to conserve remnant Renosterveld fragments.     

Effects of fertiliser addition and subsequent gopher disturbance on a serpentine annual grassland community

Summary Application of slow release fertiliser to small (0.5x1 m) plots within a serpentine annual grassland community led to significant increases in above-ground biomass and a shift in species relative abundances. In fertilised plots the native forb species which usually dominate the grassland were almost totally replaced by grasses. In the years following initial fertiliser application, a heavy mulch formed from the previous year's grass growth allowed establishment of grass species such as Bromus mollis but significantly reduced forb establishment. Gopher disturbance of fertilised plots in the second and third years of the experiment effectively removed the grass mulch and allowed re-establishment of forb species.     

Specific Interactions between Local Metallicolous Plants Improve the Phytostabilization of Mine Soils

At present, no efficient technique is available for cleaning up soils which are highly polluted by heavy metals. Limiting the movement of pollutants out of the contaminated area by creating a dense and persistent plant cover appears to be the more reasonable approach. In this context, phytostabilization is a technique that uses metallicolous plants to revegetate highly polluted soils. This paper presents the results of an experiment performed in situ using metallicolous ecotypes of four plant species native to the Mediterranean French region, and grown in different combinations at a polluted site over two years. The soils were highly polluted with zinc, cadmium and lead. The aim was to find the best species mixture in terms of cover, biomass and duration. The four species used were the biennial legume Anthyllis vulneraria, two perennial grasses, Festuca arvernensis and Koeleria vallesiana, and the perennial forb Armeria arenaria. Mixtures which included A. vulneraria, and especially when in combination with F. arvernensis, showed the highest values of cover and biomass. After flowering, the biennial individuals of A. vulneraria disappeared but subsequent germination and survival of seedlings occurred abundantly under the two grasses. Mixtures with A. arenaria showed the lowest values of cover and biomass. Soil nitrogen increased in the plots with A. vulneraria as well as the concentration of essential nutrients (N P K) in the aerial parts of the two grasses. In contrast, the concentration of metals (Zn Pb Cd) decreased in the aboveground biomass of the latter in the same plots. These results show that reciprocal facilitation effects can act in heavy metal polluted environments, and that phytostabilization efforts in the Mediterranean region can be improved by using mixtures including local metallicolous legume and grass species.     

Vegetation succession of abandoned croplands in Ruanliang and Yingliang in the Ordos Plateau

Shrub encroachment has been a key phenomenon in arid and semi-arid grasslands over the last century. However, little research has been dedicated to vegetation dynamics in the abandoned croplands, which are surrounded by shrub-encroached grasslands. In this study, several abandoned croplands in Ruanliang and Yingliang in the Ordos Plateau were selected, and the biomass, coverage, density, root pattern, and plant litter dynamics were studied. The results showed that: (1) The abandoned croplands in Ruanliang experienced three community types, including weeds community, the subshrub Artemisia ordosica community, and the perennial grass community, while the abandoned croplands in Yingliang experienced three community types, including weeds community, perennial Stipa bungeana with Artemisia frigida community, and S. bungeana community. (2) The important value for the annual or biennial grass in abandoned croplands in Ruanliang declined during the restoration process, for the perennial grass it increased, and for the subshrub it first increased and then went down to zero. In Yingliang abandoned croplands, however, the perennial grass remained dominant during the succession process. (3) The root of A. ordosica in Ruanliang abandoned croplands was mainly distributed in soil depths of 0–30?cm; the root of the perennial grass was mainly in the 0–20?cm range, and S. bungeana was found at soil depths of 0–5?cm. To restore to a natural vegetation state, about 20?years would be needed to recover the total biomass, and 10?years would be needed to restore the vegetation coverage in Ruanliang abandoned croplands. For Yingliang abandoned croplands, about 15 and 20?years would be needed to restore the total biomass and vegetation coverage, respectively, to a state of natural vegetation.     

Plant responsiveness to variation in precipitation and nitrogen is consistent across the compositional diversity of a California annual grassland

Question: How does responsiveness to water and Nitrogen (N) availability vary across the compositional and functional diversity that exists in a mesic California annual grassland plant community? Location: Northern California annual grassland. Methods: A mesocosm system was used to simulate average annual precipitation totals and dry and wet year extremes observed in northern California mesic grasslands. The effects of precipitation and N availability on biomass and fecundity were measured on three different vegetation types, a mixed grass forb community, and a forb and a grass monoculture. The treatment effects on plant community composition were examined in the mixed species community. Results: While growth and seed production of the three vegetation types was inherently different, their responses to variation in precipitation and N were statistically similar. Plant density, shoot biomass, and seed production tended to increase with greater water availability in all vegetation types, with the exception of a consistent growth reduction in high precipitation (1245 mm) plots in the first year of the study. Shoot biomass responded positively to N addition, an effect that increased with greater water availability. Nitrogen addition had little effect on plant density or seed production. In the mixed grass‐forb community, biomass responsiveness to water and N treatments were consistently driven by the shoot growth of Avena barbata, the dominant grass species. Conclusions: Vegetation responses to changes in precipitation and N availability were consistent across a range of composition and structural diversity in this study. Plant growth and seed production were sensitive to both increased and decreased precipitation totals, and the magnitude of these responses to N availability varied depending on soil moisture conditions. Our results suggest the impacts of changing precipitation regimes and N deposition on annual productivity of California grasslands may be predictable under different climate scenarios across a range of plant communities.     

Postwildfire seeding to restore native vegetation and limit exotic annuals: an evaluation in juniper‐dominated sagebrush steppe

Reestablishment of perennial vegetation is often needed after wildfires to limit exotic species and restore ecosystem services. However, there is a growing body of evidence that questions if seeding after wildfires increases perennial vegetation and reduces exotic plants. The concern that seeding may not meet restoration goals is even more prevalent when native perennial vegetation is seeded after fire. We evaluated vegetation cover and density responses to broadcast seeding native perennial grasses and mountain big sagebrush (Artemisia tridentata Nutt. spp. vaseyana [Rydb.] Beetle) after wildfires in the western United States in six juniper (Juniperus occidentalis ssp. occidentalis Hook)‐dominated mountain big sagebrush communities for 3 years postfire. Seeding native perennial species compared to not seeding increased perennial grass and sagebrush cover and density. Perennial grass cover was 4.3 times greater in seeded compared to nonseeded areas. Sagebrush cover averaged 24 and less than 0.1% in seeded and nonseeded areas at the conclusion of the study, respectively. Seeding perennial species reduced exotic annual grass and annual forb cover and density. Exotic annual grass cover was 8.6 times greater in nonseeded compared to seeded areas 3 years postfire. Exotic annual grass cover increased over time in nonseeded areas but decreased in seeded areas by the third‐year postfire. Seeded areas were perennial‐dominated and nonseeded areas were annual‐dominated at the end of the study. Establishing perennial vegetation may be critical after wildfires in juniper‐dominated sagebrush steppe to prevent the development of annual‐dominated communities. Postwildfire seeding increased perennial vegetation and reduced exotic plants and justifies its use.