高寒草毡层基本属性与固碳能力沿水分和海拔梯度的变化

高寒草毡层是高原寒区自然植被下形成的松软而坚韧且耐搬运的表土层,认识其生态功能是促进草牧业生产休养保护和工程施工主动利用的前提。通过对青藏高原东部若尔盖高原植被的广泛调查,在布设沼泽、退化沼泽、沼泽化草甸、湿草甸、干草甸和退化草甸水分梯度群落样地,以及亚高山草甸、亚高山灌丛草甸、高山灌丛草甸和高山草甸海拔梯度群落样地的基础上,通过对不同类型群落样地草毡层容重、土壤颗粒组成和土壤有机碳(SOC)含量的测定分析,比较了水分和海拔梯度下草毡层固碳能力。结果表明,草毡层厚度平均为30cm,沼泽湿地草毡层容重最小,SOC含量在300g/kg以上;退化草甸容重最高,SOC含量显著下降。不同群落草毡层SOC密度在10—24kg C/m~2之间,随着土壤水分有效性的降低而降低;高山灌丛草甸草毡层SOC密度比草甸高15%。研究得出,保持草毡层稳定的质量含水量阈值为30%,SOC含量阈值为30g/kg;高寒植被草毡层在沼泽到草甸的退化演替中,容重、紧实度变大,有机碳含量减少,碳密度和碳储量下降;灌丛草甸的固碳能力大于草甸,但灌丛草甸的生产功能降低;保持可持续发展的草地生产能力,维护固碳生态功能,需要防止草毡层退化,抑制草甸向灌丛草甸演替。     

Long‐term influence of sod cutting depth on the restoration of degraded wet heaths

Temperate heaths have an unfavorable conservation status in most European biogeographical regions. Increasing nitrogen levels promote competitive grass species such as Molinia caerulea, which is a main threat to heathland conservation in Europe. This article investigates the long‐term influence of sod cutting and the resulting changes in soil properties on the heath composition, integrity, and structure. In 15 nature reserves across the northern half of Belgium, we used (1) a large number of plots (203); (2) a broad range of sod cut depths (2–40 cm), and (3) a temporal dimension that describes how long the effects of sod cutting persist (census up to 19 years after sod cutting). Multivariate analyses were used in order to explore the influence of sod cut depth and time after sod cutting on the soil and vegetation properties. There was a positive relationship between sod cut depth and soil pH and water level, and a negative relationship with Al³⁺, NH₄⁺, and total organic matter (TOM). However, only a limited number of typical (target) species appeared after sod cutting, and then only weakly. Most of the time they remained a minor component of the restored vegetation. Moreover, M. caerulea reappeared and its cover significantly increased during the years following sod cutting. Although we were able to show that sod cut depth has a differential effect on soil properties and vegetation recovery, it also appeared that sod cutting does not restore wet heaths in the long term when applied in regions with high nitrogen deposition.     

Plant traits: Their role in the regeneration of alpine plant communities in sub‐arctic Finland

Abstract. Question: How do the relative frequencies of plant traits (clonality, growth form, seed weight, diaspore morphology) vary during the life cycle and how does this affect regeneration? Location: Alpine meadow and heath communities at Kilpisjärvi, sub‐Arctic Finland. Methods: Control plots and three treatments were used to measure relative species abundances for five life cycle stages: standing vegetation, seed rain, seed bank and seedlings emerging in gaps and in closed vegetation. Results: The relative frequencies of plant traits varied between the life cycle stages. The meadows were dominated by weakly clonal herbs, small or intermediate seeds and unappendaged diaspores, while the heaths were dominated by clonal dwarf shrubs, small seeds and fleshy fruits. In the meadows, species with small seeds dominated during the seed rain and in the seedling stage in gaps, while species with intermediate seeds dominated the seed bank and the seedling stage in closed vegetation. Species with unappendaged diaspores dominated throughout the life cycle. In the heaths, seed bank and seedling stage were practically absent. Conclusions: The observed differences in plant trait spectra between life cycle stages indicate that important environmental factors differ among the stages. Small seeds are advantageous for dispersal, whereas intermediate seeds have a greater probability of germinating and establishing in closed vegetation. Appendages facilitate dispersal, whereas unappendaged diaspores favour seed burial. Although the plant growth form spectrum largely reflects environmental constraints during the regeneration cycle, information on seed weight and diaspore morphology improves our knowledge of the relative importance of morphological adaptations of sexual structures in different stages during the life cycle.     

Reinstatement of traditional mowing regimes counteracts population senescence in the rare perennial Primula vulgaris

Question: Traditional management of grassland verges or ditch banks included mowing as a way to provide additional harvesting of hay. Nowadays, such sites are often left unmanaged, as mowing verges is no longer profitable in modern agricultural systems. Are vulnerable plant species able to withstand competition with the surrounding vegetation and maintain viable populations under these circumstances? How do they respond to reinstatement of traditional mowing regimes? Location: Oedelem, northwestern Belgium. Methods: To investigate the effect of reinstatement of the rare perennial Primula vulgaris, demography and adult plant performance were monitored in a grassland verge between 1999 and 2003 under different mowing regimes. Year transitions between life stages were analysed with matrix population models. To disentangle the contributions of the deviations in different life stage transitions to the variation in overall population growth rate, life table response experiments were used. Results: Both management and year had a strong impact on demographic traits of P. vulgaris. If plots were left unmanaged, lower plant performance and declining population growth rates were observed. While population growth rates differed significantly between mowing regimes, mowing of plots only in July did not differ from mowing in July and October in terms of vegetative and reproductive output of adults. Mowing twice a year appeared to be most efficient in increasing population growth rate both by raising recruitment and growth of individuals into large reproductive adults. Conclusions: Large P. vulgaris populations show a good ability to recover from recent abandonment of traditional management regimes. By mowing twice a year, managers are able to target vital rates that are most influential: growth and flowering of adult individuals.     

Effects of intraspecific and interspecific density on the demography of a perennial herb, Sanicula europaea

We examined the effects of intraspecific and interspecific competition on demographic processes in the perennial herb Sanicula europaea by manipulating the density of neighbouring plants. We followed the response in terms of survival, growth and reproduction and in terms of seedling recruitment. The demographic data from all phases of the life cycle enabled us to assess also the overall effects of treatments on population growth rate (λ) by transition matrix models. We also decomposed the differences in λ between control and treatments, using life table response experiments (LTRE). To study the effects of competition on recruitment in more detail and to evaluate the role of seed availability, we sowed seeds at different densities with or without vegetation removal.
Vegetative growth and flowering frequency of established individuals was not significantly affected by removal treatments, which suggest no, or a delayed response to released competition. Neighbour removal had no effect on seedling emergence but enhanced recruitment through a higher seedling survival. Conspecific and simultaneous conspecific and heterospecific removal of plants led to an increase in population growth rate (λ), whereas heterospecific removal alone led to a decrease. Emergence of seedlings and fate of vegetative established individuals contributed most to differences in λ between the control and the different treatments. Seed addition enhanced seedling emergence but, as seedling and juvenile survival were density dependent, densities of established individuals appear not to be seed limited.
In S. europaea removal treatments had different effects on established individuals and recruitment. This suggests that studies quantifying the effects of competition over the entire life cycle and performed in a natural environment are necessary to assess the importance of competition in perennial plant populations.     

Sensitivity of seedling recruitment to moss, litter and dominant removal in an oligotrophic wet meadow

The effect of a dominant species, the litter layer, and the moss layer on seedlings and established vegetation was evaluated in two manipulative experiments in an oligotrophic wet meadow (Molinion with some features ofViolion caninae according to phytosociological classification). In the first experiment, the dominant species (Nardus stricta), litter layer, and litter layer together with the moss layer were removed and the response of the established vegetation and seedlings were compared with a control. Results revealed that after one season there was no significant effect of the treatments on established vegetation, but seedling recruitment was significantly affected. The greatest increase of seedling recruitment for many species was observed in the plots with the moss layer removed. In the second experiment, seeds ofSelinum carvifolia were sown into plots subjected to the following treatments: complete vegetation removal, mowing, mowing combined with removal of the moss layer, and an untreated control. The highest number of seedlings was found in plots with the vegetation removed, but the seedling recruitment was nearly as high in plots with the moss layer removed. Low numbers were found in mown plots and the lowest in the untreated control. The results show that seedling recruitment is more sensitive to competition than the established vegetation, at least over one season. This supports the idea of the importance of the regeneration niche for the maintenance of diversity in grassland communities.     

Effects of different Rhododendron control methods in eastern beech (Fagus orientalis Lipsky) ecosystems in the western Black Sea region of Turkey

Intensive weed control and plot preparation practices have become a critical and integral part of productive beech forest management in Turkey’s coastal Black Sea region (BSR). This study was conducted in an eastern beech forest of 100+ year old in the BSR to evaluate ecosystem effects of three different experimental Rhododendron ponticum understory control methods with a randomised block design, including manual grubbing, foliar and cut stump spraying with imazapyr (Arsenal) and foliar and cut stump spraying with triclopyr (Garlon). Untreated vegetation plots served as controls. Evaluation of these treatments included their effects on understory and forest floor biomass and nutrients (C, N, P, S, K, Ca and Mg) and effects on soils, including bulk density, pH, soil nutrients (C, N, P and S), exchangeable cations (K, Ca and Mg) and soil cation exchange capacity (CEC). Grubbing and imazapyr treatments had greatly reduced the amount of understory biomass 5 years after application (P = 0.002). Triclopyr treatment also had a major effect on understory vegetation control, but by 5 years later, about 10% of the rhododendron originally present on these plots had gradually re‐sprouted and partially covered the plots. Five years after woody vegetation control treatments, at the 0‐ to 20‐cm depth, treatments did not appear to affect soil bulk density, pH and CEC. For the upper 20‐cm soil depth, the exchangeable soil K concentration at the 10‐ to 20‐cm depth on triclopyr‐treated plots was 33% higher than on grubbing plots, and it was twice that of imazapyr application plots. Imazapyr plots had almost 11 times more dead organic matter on the forest floor than there was on grubbing plots. Forest floor C concentrations on imazapyr plots were 26 and 14% greater than those on grubbing and triclopyr plots, respectively. Total ecosystem (forest floor + understory + soil exchangeable) Ca content was 50% higher on imazapyr plots than that on triclopyr plots, while the ecosystem K pool on imazapyr treatment plots was 27% lower than that on triclopyr plots. Herbicides can be used as an alternative for achieving some forest management objectives when other vegetation control methods are not feasible or economical. It is recommended that vegetation control not be used on steep slopes because of greater risk of soil erosion. There may be benefits in encouraging slash disposal by fire after imazapyr treatments, thus removing recalcitrant understory residues left on the forest floor and releasing the essential nutrients within them.     

Does microclimate affect grasshopper populations after cutting of hay in improved grassland?

The microclimate of an improved hay meadow was studied using Tinytag dataloggers to record sward temperature after cutting. Temperatures in the sward were then compared to grasshopper abundances to see if mowing created an excessively hot microclimate unfavourable for sustained grasshopper activity in mid summer. The abundance of Chorthippus albomarginatus and Chorthippus parallelus was significantly reduced on the hay plots compared to the unmanaged control swards, which may have been due to high sward temperatures created by the absence of tall, shady vegetation in which grasshoppers may take refuge to avoid overheating. This study suggests that a combination of mortality caused by the physical process of mowing, and high sward temperatures created by removal of the standing crop by cutting may cause the low abundance of grasshoppers in improved grassland in eastern England. This research is particularly important when considering the orthopteran assemblages of Environmental Stewardship Scheme field margins where mowing for hay in July and August may seriously reduce grasshopper populations. If mowing of grassland has to occur during the grasshopper season, we suggest a later cut in September or a system of rotational mowing, leaving areas of uncut grassland as shelter.     

Spatio-Temporal Variation in Contrasting Effects of Resident Vegetation on Establishment,Growth and Reproduction of Dry Grassland Plants: Implications for Seed Addition Experiments

Successful establishment of plants is limited by both biotic and abiotic conditions and their interactions. Seedling establishment is also used as a direct measure of habitat suitability, but transient changes in vegetation might provide windows of opportunity allowing plant species to colonize sites which otherwise appear unsuitable. We aimed to study spatio-temporal variability in the effects of resident vegetation on establishment, growth and reproduction of dry grassland species in abandoned arable fields representing potentially suitable habitats. Seeds were sown in disturbed (bare of vegetation and roots) and undisturbed plots in three fields abandoned in the last 20 years. To assess the effects of temporal variation on plant establishment, we initiated our experiments in two years (2007 and 2008). Seventeen out of the 35 sown species flowered within two years after sowing, while three species completely failed to become established. The vegetation in the undisturbed plots facilitated seedling establishment only in the year with low spring precipitation, and the effect did not hold for all species. In contrast, growth and flowering rate were consistently much greater in the disturbed plots, but the effect size differed between the fields and years of sowing. We show that colonization is more successful when site opening by disturbance coincide with other suitable conditions such as weather or soil characteristics. Seasonal variability involved in our study emphasizes the necessity of temporal replication of sowing experiments. Studies assessing habitat suitability by seed sowing should either involve both vegetation removal treatments and untreated plots or follow the gradient of vegetation cover. We strongly recommend following the numbers of established individuals, their sizes and reproductive success when assessing habitat suitability by seed sowing since one can gain completely different results in different phases of plant life cycle.     

Seasonal Effects of Four Control Methods on the Invasive Morrow's Honeysuckle (Lonicera morrowii) and Initial Responses of Understory Plants in a Southwestern Pennsylvania Old Field

The first step in restoration often involves the removal of invasive plants, but few studies have determined if the response of plant communities matches management goals. The shrub Morrow's honeysuckle ( Lonicera morrowii Gray) is one of a suite of exotic bush honeysuckle species that have become pervasive woody invaders in eastern North America. In 2004, we tested four control methods (cut, mechanical removal, stump application of glyphosate, and foliar application of glyphosate) during late spring and early autumn within a degraded meadow at Fort Necessity National Battlefield, Pennsylvania, U.S.A. Our restoration goals are to control Morrow's honeysuckle, restore native vegetation, and mimic the conditions present in the mid-1700s. We established forty-five 5 × 5–m plots to measure woody species; five plots of each treatment method were treated in spring, whereas the remaining five were treated in autumn. We maintained five control plots. Before control, mean density of Morrow's honeysuckle was 67,920 ± 4,480 shrubs/ha. Foliar application of herbicide and mechanical removal were most effective at reducing the number of shrubs (≥62%). Overall, our treatments were less successful (26–68% reduction) than reported control efforts of other bush honeysuckle species; the sheer number of shrubs coupled with their open habitat made control efforts difficult. Spring treatments, particularly cut and mechanical treatments, had higher metrics of herbaceous community quality. However, continued restoration efforts, including follow-up treatments, White-tailed deer ( Odocoileus virginianus ) control, and the planting of native seeds and saplings, should be employed to favor the establishment of native seedlings and herbs.     

Oscillating vegetation dynamics in a wet heathland

Abstract. Question: The significance of disturbances caused by periodical inundation was investigated with respect to its effects on vegetation dynamics, species richness and fluctuations, and to the relevance of certain plant properties. Location and Method: At a sod‐cut stand within nutrient‐poor inland sand dunes, permanent plots along a transect were surveyed over a period of up to nine years after sod cutting. Results: In contrast to never inundated plots, periodically inundated plots were characterized by low vegetation cover and by high numbers of species belonging to many different communities, each of them with a low cover. Periodical inundations favoured the presence of pioneers, species tolerant of disturbances, species adapted to wet conditions and stoloni‐ferous species. Furthermore, annual fluctuations of species within each plot were higher and most species occurred only sporadically. Discussion: A comprehensive model is presented describing the relevant processes identified in the littoral zone. Changing water tables result in the creation of gaps. The re‐colonization of these gaps follows mainly from vegetative regeneration and less to the dispersion of diaspores. Highest species numbers in the zone of moderate disturbances result from a high rate of re‐colonization in spite of local extinctions following each disturbance event. It is suggested that colonization abilities are among the most important features for species occurrence at a site rich in disturbances (more important than competitive abilities and more important than a slow rate of displacement). For nature conservation such sites are very important, because they allow (rare) pioneer species to survive for longer periods of time.     

Pattern and dynamics of the ground vegetation in south Swedish Carpinus betulus forests: importance of soil chemistry and management

The vegetation and environmental conditions of south Swedish hornbeam Carpinus betulus forests are described with data from 35 permanent sample plots The main floristic gradient of the ground vegetation is closely related to acid-base properties of the top soil base saturation, pH and organic matter content Other floristic differences are related to tree canopy cover and the distance of the sample plots to the Baltic coast Species richness of herbaceous plants typical of forests increases with soil pH, The number of other herbaceous species, occurring in both forests and open habitats, and of woody species is not related to pH Comparisons of vegetation data from 1983 and 1993 show relatively small compositional differences of the herbaceous forest flora The number of other herbaceous species increased considerably m those plots where canopy trees had been cut after 1983 The number of new species in managed plots increases with soil pH Species losses and gains of the herbaceous forest flora between 1983 and 1993 are generally lower as compared with other herbaceous species and woody species However, the ground cover of herbaceous forest species, especially of Oxalis acetosella and Lamium galeobdolon , was considerably lower in 1993 as compared to 1983 in both unmanaged and managed plots Possible explanations for this decrease are current soil acidification and drought during the growing season     

Reed cut,habitat diversity and productivity in wetlands

There is a conflict between nature conservation and thatching industry regarding the management of reedbeds. On one hand, reedbeds are of an economical importance by providing thatching material, on the other hand, they harbour several endangered species. Reedbeds are typically managed by winter cutting, but its impacts on biodiversity are poorly understood. Our aim was to study the effects of winter cutting on the habitat diversity and structural heterogeneity of wetlands in a lowland alkali landscape (East-Hungary). We tested the following hypotheses: (i) Both diversity of plant species and habitat diversity are lower in winter cut wetlands compared to unmanaged stands. (ii) The distribution of biomass (green biomass, litter and standing dead biomass) is more homogeneous in winter cut wetlands compared to unmanaged ones. We found that winter cutting decreased habitat diversity and structural heterogeneity at multiple scales. Number of plant species and all measures of habitat diversity (number of patches, vegetation types and the length of vegetation margins) had lower scores in cut wetlands than in unmanaged ones. We found that unmanaged wetlands harboured high amount of accumulated biomass and they also maintained high habitat diversity likely due to the heterogeneous distribution of the biomass. In unmanaged wetlands, biomass accumulation did not decrease habitat diversity and also contributed to a higher structural heterogeneity. In cut wetlands, expansion of reed was an important driver of the decrease in habitat diversity and structural heterogeneity. Reed expansion likely overrode fine-scale edaphic conditions (hydrology and salinity) in shaping vegetation patterns; thus we suggest to avoid intensive winter cutting.     

Population dynamics of Gentiana pneumonanthe and Rhynchospora fusca during wet heathland restoration

Abstract. The population dynamics and reproductive strategies of two rare wet heathland species, Gentiana pneumonanthe and Rhynchospora, were studied in experimental permanent plots in a wet heathland near Bremen, NW Germany, to assess how effective sod cutting and mowing are in promoting these species. In one experiment, small plots (0.25 m² - 4 m²) were sod-cut or mown; in the second, one large plot 30 mx 50m) was sod-cut. The development of the vegetation and the number of shoots of the two target species were recorded annually. Sod cutting lead to the highest shoot numbers of Gentiana in the long run, whilst mowing was more effective at the beginning of the experiment. Seedlings and adult shoots slowly became more and more abundant after sod cutting. In contrast, Rhynchospora soon formed closed stands after sod-cutting, first through seed germination and then through fast clonal growth of the established individuals. Moist soil or short inundations promoted the germination and seedling establishment of Gentiana, whereas drought negatively affected seedling recruitment. Long periods of inundation severely reduced the population at first, but high numbers of seedlings were found in the following growing season. For the disturbance-dependent Gentiana and Rhynchospora, the availability of gaps within the vegetation is of crucial importance. To promote existing populations, we suggest small-scale sod cuttings which create gaps without disturbing existing flowering individuals too much. For degenerated stands of wet heathland we recommend large-scale sod cutting to activate the seed bank. Additionally, seed introduction may be helpful to encourage the development of a wet heathland with characteristic floristic composition.     

Establishment of Picea abies seedlings in a central European mountain grassland: an experimental study

Abstract. Secondary meadows in the Kru?né hory mountains, central Europe, are not colonized by woody species, although they have been abandoned for half a century and are surrounded by Picea abies (Norway spruce) forests. The causes of inhibition of establishment of Norway spruce seedlings in the meadows were tested experimentally. The experiment was started in a masting year to ensure sufficient seed input. Four treatments (vegetation cut; vegetation cut and litter removed; all above-ground biomass and topsoil removed; control) were combined in a factorial design. The effect of browsing, mainly by deer, was assessed by fencing half of the experimental plots. Seedling establishment differed among treatments (all pair-wise differences were significant) but was independent of fencing. In contrast, seedling survival was influenced both by the treatment and fencing. At the end of the second year, only the plots with all biomass and organic topsoil removed supported viable populations of spruce seedlings. Dense herb cover and a thick layer of slowly decaying litter are considered the main factors inhibiting the establishment of woody species.     

Vegetation Control Treatments to Favor Naturally Regenerated Betula alleghaniensis Saplings Following Seed-Tree Cut: Sapling Monitoring Two Years after Treatment

Control of competing vegetation is recommended to ensure successful Yellow birch (Betula alleghaniensis Britton) regeneration within juvenile stands that do not sustain high enough sapling densities of this species. Four contrasting vegetation control treatments were tested to determine their effect on the growth and vigor of eight‐year‐old B. alleghaniensis saplings regenerating after final cutting of a shelterwood seed cut. Vegetation control treatments were TC (total circular removal), PC (circular removal of codominant competing vegetation), TS (total semicircular removal on 180° section), and NC (no vegetation control). Two years after treatment application, diameter growth significantly improved in response to vegetation control treatments, whereas sapling height growth did not. This pattern of biomass allocation was directly related to sapling etiolation, which increased with decreasing severity of vegetation removal. As a result, application of vegetation control, especially TC and PC treatments, was valuable in reducing signs of stress in saplings. However, increasing the severity of vegetation removal also made saplings more conspicuous to herbivores, which increased browsing, especially in the TC and PC treatments. Browsing was sufficient in some plots of the TC and PC treatments to overcome the vigor and diameter growth enhancements observed when browsing was negligible. In contrast to the TC and PC treatments, the TS treatment kept browsing very low while largely removing competition. The results suggest that B. alleghaniensis saplings established after final cutting of a shelterwood seed cut do take advantage of vegetation control treatments, but the decision to apply these treatments must include consideration of local herbivore population densities.     

Experimental assessment of initial revegetation on abandoned paths in temperate deciduous forest

Question: Do soil treatments and addition of seed facilitate rapid vegetation restoration on forest paths excluded from trampling? Location: Six mesophilic mixed deciduous Querco‐Fagetea forests in Flanders, northern Belgium. Methods: Enclosures on paths were excluded from trampling by fencing. In a full factorial design, plots were subjected to seeding, soil scarification, addition of organic material and inoculum. The following two years, seedling establishment and growth were sampled during spring and summer. Soil treatments and seeding effect was tested and seedling occurrence was analysed in relation to species' origin. Results: Spontaneous re vegetation was significant in all plots since fencing. Throughout the observation period seedling cover and height continued to increase. Seeding had an overall effect on seedling density, cover and height. Some soil treatment interactions significantly enhance re vegetation, although each individual soil treatment had no significant effect. Regardless of the seeded individuals, invading species mostly originated from the surrounding area and the seed bank. Conclusion: The preliminary results of this experiment imply that seeding is the only treatment which has a positive effect on re vegetation success in all circumstances, provided that the exclusion from trampling is effective.     

Fire as a control agent of demographic structure and plant performance of a rare Mediterranean endemic geophyte

We examine the effects of fire and/or surrounding vegetation cover on demographic stage densities and plant performance for a rare endemic geophyte, Acis nicaeensis (Alliaceae), in Mediterranean xerophytic grasslands of the 'Alpes-Maritimes' French 'département', through sampling plots in unburned and burned treatments. Fire increases density of flowering individuals and seedling emergence, as well as clump densities and number of individuals per clump, per limiting vegetation height and cover, and increasing bare soil cover. In contrast, fire has no effect on reproductive success. Nevertheless, two growing seasons after fire, all parameters of demographic stages and plant performance do not significantly differ between the two treatments. Small-scale fire is beneficial for the regeneration of this threatened geophyte at a short-time scale. In this context, a conservation planning with small and controlled fires could maintain the regeneration window for populations of rare Mediterranean geophytes.     

Diversity and persistence of arbuscular mycorrhizas in a low-Arctic meadow habitat

Little is known about the ecology and diversity of arbuscular mycorrhizal (AM) fungi in Arctic ecosystems. Here, the diversity and composition of the AM fungal community and its response to host plant community composition were studied in a low-Arctic meadow habitat. The natural vegetation in two low-Arctic meadow sites was manipulated. Plots with natural vegetation, monoculture and no vegetation were established. Seeds of Solidago virgaurea were sown into the plots and the AM fungal community in the seedling roots was analysed using the terminal restriction fragment length polymorphism (T-RFLP) method. The vegetation manipulation treatments affected the community composition but not the diversity of AM fungi found in S. virgaurea roots. The diversity of AM fungi was higher in S. virgaurea roots in the site with naturally higher plant species diversity. These results show that AM fungi in low-Arctic meadows are able to survive for a period of 2 yr without a host plant. This ability buffers the AM fungal community against short-term changes in host plant community composition and diversity.