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Abstract Cliffs contain one of the least known plant communities, which has been overlooked in biodiversity assessments due to the inherent inaccessibility. Our study adopted the unmanned aerial vehicle (UAV) with the telephoto camera to remotely clarify floristic variability across unreachable cliffs. Studied cliffs comprised 17 coastal and 13 inland cliffs in Gageodo of South Korea, among which 9 and 5 cliffs were grazed by the introduced cliff-dwelling goats. The UAV telephotography showed 154 and 166 plant species from coastal and inland cliffs, respectively. Inland cliffs contained more vascular plant species (P

The Pinus halepensis (Aleppo pine) forests prevailing in the western part of the Mediterranean Basin are amongst the most severely affected by fire due to their inherent flammability. Our understanding of the environmental factors driving post-fire community dynamics is currently limited by the lack of time-series data at temporal scales. In this present study, we analyzed a chronosequence of Greek Aleppo pine forests spanning a post-fire period of 65 years. Our goal is to explore the role of post-fire age, altitude, exposure, slope level, parent-rock material, rock cover, and cover of evergreen sclerophyllous shrubs (maquis) on plant assemblage diversity (species richness and Menhinick's diversity index) and composition. Post-fire age had a significant effect on taxonomic distinctness and community turnover but not on species richness. Taxonomic distinctness increased with post-fire age due to a higher prevalence of the families Fabaceae, Asteraceae, and Poaceae during the early post-fire period. Maquis cover was significantly associated with Menhinick's diversity index, taxonomic distinctness, and community turnover. Exposure and slope influenced only Menhinick's diversity index. The turnover in species composition was primarily driven by the geographical proximity of the forests and secondarily by post-fire age and the maquis cover. This highlights the importance of the initial floristic composition in the process of autosuccession after a fire in Mediterranean-climate ecosystems. [ABSTRACT FROM AUTHOR]

Cliffs contain one of the least known plant communities, which has been overlooked in biodiversity assessments due to the inherent inaccessibility. Our study adopted the unmanned aerial vehicle (UAV) with the telephoto camera to remotely clarify floristic variability across unreachable cliffs. Studied cliffs comprised 17 coastal and 13 inland cliffs in Gageodo of South Korea, among which 9 and 5 cliffs were grazed by the introduced cliff-dwelling goats. The UAV telephotography showed 154 and 166 plant species from coastal and inland cliffs, respectively. Inland cliffs contained more vascular plant species (P < 0.001), increased proportions of fern and woody species (P < 0.05), and decreased proportion of herbaceous species (P < 0.001) than coastal cliffs. It was also found that coastal and inland cliffs differed in the species composition (P < 0.001) rather than taxonomic beta diversity (P = 0.29). Furthermore, grazed coastal cliffs featured the elevated proportions of alien and annual herb species than ungrazed coastal cliffs (P < 0.05). This suggests that coastal cliffs might not be totally immune to grazing if the introduced herbivores are able to access cliff microhabitats; therefore, such anthropogenic introduction of cliff-dwelling herbivores should be excluded to conserve the native cliff plant communities. [ABSTRACT FROM AUTHOR]

The interruption of plant‐pollinator interactions may threaten global plant diversity, food security and ecosystem stability. Recent reports of strong declines in both insects and plants point to insect decline as a driver of plant decline. However, it is still unknown whether these trends are related as plants often produce seeds without the need for insect pollinators, and to what extent insect‐pollinated plants have declined in relation to plants not pollinated by insects.In this study, we hypothesise that natural plant communities have shifted away from insect‐pollination. We combined 365,768 vegetation plots from 1930 to 2017 in the Netherlands and plant traits to assess the changes in occurrences of plants pollinated by different modes. Furthermore, we included key drivers in plant decline—specifically nitrogen, moisture and habitat types—as interaction factors to explore the persistence of the observed changes under different environmental conditions.The proportion of insect‐pollinated plants has declined while that of wind‐pollinated plants has increased over the last 87 years. This proportional change reflects an absolute decrease in the number of insect‐pollinated species and an increase in the number of wind‐pollinated species.Synthesis and applications. This study implies that Dutch landscapes are losing insect‐pollinated plant species, which is likely due, at least in part, to the decline in pollination services. Our results of quantifying the decline in insect‐pollinated plants support the necessity and urgency of taking conservation initiatives. Several management strategies and policy recommendations could be applied to alleviate the decline of insect‐pollinated plants and ensure crop safety. For example, conserving natural environments by reducing nitrogen deposition may support local plants and insect pollinators. Additionally, there is a particular need for focused efforts to protect natural grasslands, as these areas harbour many insect‐pollinated plants, which have experienced declines. Finally, monitoring and assessing the state of both pollinators and (insect‐pollinated) plants is needed to assess the progress of conservation measures. While recognising the interdependence of pollinators and pollinated plants, it is crucial to extend efforts beyond pollinator conservation alone to effectively safeguard insect‐pollinated plants and ensure crop safety. [ABSTRACT FROM AUTHOR]

[Objective] The changes in plant community composition and vertical structure under natural restoration were studied in order to provide a reference for vegetation construction and high-quality development of the Loess Plateau. [Methods] Using the method of space instead of time, species composition and diversity characteristics of vegetation from abandoned cropland to top community in the Ziwuling forest area were investigated and analyzed. A vegetation vertical structure index was constructed to study the vertical structure of the vegetation community and its changing trend in the succession sequence. [Results] ① A total of 115 species of vegetation in 42 families, 98 genera, and 115 species appeared in the Ziwuling forest zrea, and a total of 32 families, 77 genera, and 88 species of vegetation appeared in the succession sequence. ② In succession, the species diversity index and richness index of the community showed a significant increasing trend, The diversity and richness index values were 0.901 and 1.702 at the beginning of the succession, and 1.998 and 2.665 at the end of the succession. The middle stage showed a unimodal trend, and the two indices were 2.21 and 3.05. The evenness index did not change significantly. ③ During the succession process, each tree factor showed an increasing trend. The DBH was 12.13 cm at the initial stage of succession and increased to 22.19 cm at the end; the crown width increased from 11.64 m2 to 41.54 m2; and the tree biomass increased from 54.07 t/hm2 to 175.13 t/hm2. However, the indicators of shrubs did not change significantly during the succession process. Shrub biomass showed significant peaks in the middle of succession (highest value of 9.56 t/hm2), but showed a rapid fluctuation and declining trend in the subsequent succession process. At the end of succession, shrub biomass was only 1.82 t/hm2. The thickness of the litter layer increased significantly when the shrub community was succeeded by the tree community, but the litter coverage was not significantly different between the succession stages. ④ The overall vertical structure index in the early stage of succession was low and similar, ranging from 0.086 to 0.104, and rapidly increased to 0.349 in the middle stage of succession, reaching a maximum value of 0.477 near the end of the succession. The vertical structure index of understory vegetation was highest in the middle of the succession (0.342), thereafter decreasing and tending to be stable at the end of succession (0.195~0.246). [Conclusion] With natural succession, species diversity and community richness significantly improved, and a single peak appeared in the middle of the succession. The overall vertical structure of the community became more complex, and the vertical structure of understory vegetation degraded during late succession.

In Semiarid Chaco, two management approaches for woody plant-encroached grassland/savannas were evaluated: ecological restoration and the African grass introduction. An experiment with five treatments was carried out: 1) reference community (Ref_Eco; a grassland/savanna in good state, used as standard of comparison); 2) grassland/savanna encroached by woody plants (Woody_Encr; the woody state of grassland/ savannas); 3) roller chopping of the encroached ecosystem, followed by grazing suppression and prescribed fire (Roll_Fire; aimed at inducing grassland/savanna ecological restoration); 4) roller chopping of the encroached ecosystem, with instantaneous seeding of Megathyrsus maximus cv. Gatton Panic and grazing suppression (Roll_Gatton Panic), and 5) roller chopping of the encroached ecosystem, with instantaneous seeding of Cenchrus ciliaris cv. Buffel Texas and grazing suppression (Roll_Buffel Texas). The last two treatments aimed to obtain new highly productive grassy states for ranching through the introduction of these African grasses. The results suggested that Ref_Eco (average herbaceous biomass [HERB]=7196.9 kg DM/ha) was dominated by shade intolerant and fire tolerant grasses, and it had good soil quality and good utilitarian range condition. Regarding Ref_Eco: a) in Woody_Encr (HERB=2192 kg DM/ha), the vegetation structure, plant composition and the utilitarian range condition were altered, but it still had good soil quality and abundant native grass populations; b) in Rol_Fire (HERB=6591.6 kg DM/ha), both the vegetation structure and good utilitarian range condition were restored, plant composition was not restored and the good soil quality was kept, and c) Roll_Gatton Panic and Roll_Buffel Texas (HERB=10972.1 and 7450.8 kg DM/ha, respectively) resulted in new grassy states integrated by native and exotic grasses with good utilitarian range condition and good soil quality. In this study case, the ecological restoration of the encroached ecosystems would be both ecologically and productively viable. So, probably the introduction of African grasses to improve ranching was not necessary. [ABSTRACT FROM AUTHOR]

Aim: Typha latifolia causes serious problems in wet meadows by overgrowing and suppressing other native plants. To determine suitable management for T. latifolia control, we addressed the following question: What are the effects of long‐term cutting at different frequencies (once or twice per year and no management) and biomass removal on cover and other characteristics of T. latifolia, and on sward productivity and plant species composition? Location: Malá Strana nature reserve, Jizerské hory Mountains, Czechia. Methods: A long‐term experiment arranged in a randomised block design with three blocks was established in 2005. Data were collected from five treatments: unmanaged control; cutting once a year in June without biomass removal and with biomass removal; cutting twice per year in June and August without biomass removal and with biomass removal. Percentage cover of T. latifolia and other vascular plant species was visually estimated and T. latifolia characteristics (tiller density, height, dry‐matter biomass [DMB] yield and litter), sward height and DMB yield were measured during 2005–2018 at the end of June. Results and Discussion: Regular cutting once or twice per year regardless of cut biomass removal led to reductions in tiller density, height, litter and DMB yield of T. latifolia. Biomass removal had only a slight tendency to affect T. latifolia characteristics. The higher frequency of cutting significantly decreased the mean T. latifolia cover, litter and DMB yield. Cutting once or twice per year regardless of biomass removal led to successive changes in plant species composition but had no effect on the species richness and evenness. Conclusions: Cutting at least once per year without biomass removal seems to be sufficient to achieve a decrease in DMB yield and litter of T. latifolia plants, and thereby maintain the wet‐meadow vegetation without loss of species richness and also preventing the overgrowth of shrubs and trees. [ABSTRACT FROM AUTHOR]

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Coastal wetlands remarkably influence terrestrial carbon (C) stock by serving as natural reservoirs for ‘blue carbon’. Anthropogenic nitrogen (N) enrichment shapes the dynamics of soil and plant communities, consequently affecting the C balance and ecosystem functions. The impacts of various levels of N enrichment on CO _2 sequestration in coastal wetlands, however, remain elusive. Here we conducted a long-term field study of N fertilization in a coastal wetland in the Yellow River Delta, China, to investigate N effects on soil properties, indicators of plant dynamics, and fluxes of ecosystem CO _2 . The results indicated that moderate N enrichment (5 g N m ^−2 y ^−1 ) stimulated C fluxes with increases in gross primary productivity (+26.4%), ecosystem respiration (+23.3%), and net ecosystem exchange (NEE, +31.5%) relative to the control. High (10 g N m ^−2 y ^−1 ) and extreme (20 g N m ^−2 y ^−1 ) amounts of N enrichment, however, had relatively minor impacts on these CO _2 fluxes. Overall, we observed a decrease in soil electrical conductivity (−24.6%) and increases in soil organic C (+25.2%) and microbial biomass C (+369.3%) for N enrichment. N enrichment also altered the composition of plant species, with a higher proportion of a local dominant species ( Phragmites australis ), and affected root biomass distribution, with more biomass near the soil surface. Structural equation modeling explained 65.2% of the variance of NEE and supported the assumption that N enrichment could alter the dynamics of soil properties and plant conditions and accelerate ecosystem CO _2 sequestration. These findings have important implications for forecasting the C cycle with increasing N deposition in coastal wetlands, contributing to the projections of the global C budget.

The Costa Rican Paramo is a unique ecosystem with high levels of endemism that is geographically isolated from the Andean Paramos. Paramo ecosystems occur above Montane Forests, below the permanent snow level, and their vegetation differs notably from that of adjacent Montane Forests. We compared the composition and beta diversity of blooming plant species using phenological data from functional plant groups (i.e., insect-visited, bird-visited and insect C bird-visited plants) between a Paramo and a Montane Forest site in Costa Rica and analyzed seasonal changes in blooming plant diversity between the rainy and dry seasons. Species richness was higher in the Montane Forest for all plant categories, except for insect-visited plants, which was higher in the Paramo. Beta diversity and blooming plant composition differed between both ecosystems and seasons. Differences in species richness and beta diversity between Paramo and the adjacent Montane Forest are likely the result of dispersal events that occurred during the last glacial period and subsequent isolation, as climate turned to tropical conditions after the Pleistocene, and to stressful abiotic conditions in the Paramo ecosystem that limit species establishment. Differences in blooming plant composition between both ecosystems and seasons are likely attributed to differential effects of climatic cues triggering the flowering events in each ecosystem, but phylogenetic conservatism cannot be discarded. Analyses of species composition and richness based on flowering phenology data are useful to evaluate potential floral resources for floral visitors (insects and birds) and how these resources change spatially and temporarily in endangered ecosystems such as the Paramo. [ABSTRACT FROM AUTHOR]

The Costa Rican Paramo is a unique ecosystem with high levels of endemism that is geographically isolated from the Andean Paramos. Paramo ecosystems occur above Montane Forests, below the permanent snow level, and their vegetation differs notably from that of adjacent Montane Forests. We compared the composition and beta diversity of blooming plant species using phenological data from functional plant groups (i.e., insect-visited, bird-visited and insect + bird-visited plants) between a Paramo and a Montane Forest site in Costa Rica and analyzed seasonal changes in blooming plant diversity between the rainy and dry seasons. Species richness was higher in the Montane Forest for all plant categories, except for insect-visited plants, which was higher in the Paramo. Beta diversity and blooming plant composition differed between both ecosystems and seasons. Differences in species richness and beta diversity between Paramo and the adjacent Montane Forest are likely the result of dispersal events that occurred during the last glacial period and subsequent isolation, as climate turned to tropical conditions after the Pleistocene, and to stressful abiotic conditions in the Paramo ecosystem that limit species establishment. Differences in blooming plant composition between both ecosystems and seasons are likely attributed to differential effects of climatic cues triggering the flowering events in each ecosystem, but phylogenetic conservatism cannot be discarded. Analyses of species composition and richness based on flowering phenology data are useful to evaluate potential floral resources for floral visitors (insects and birds) and how these resources change spatially and temporarily in endangered ecosystems such as the Paramo.

Aims: The general effects of grazing by large herbivores on plant species composition and productivity are well known. Meanwhile, how different livestock species affect community structure is not fully understood. In northern China, livestock species composition is changing rapidly and hence, it is imperative to understand the resulting effects on grassland productivity and composition. Location: Xilingol, Inner Mongolia, China. Methods: We studied how grazing by three major livestock species affects typical steppe dominated by Leymus chinensis, Stipa grandis, Cleistogenes squarrosa and Carex korshinskyi, in a 4‐year field experiment using a random block‐design with four treatments (sheep, goat, cattle, no grazing), under summer grazing at moderate intensity. We calculated above‐ground net primary productivity (ANPP) and a selectivity index (SI) based on biomass to quantify livestock forage preferences. Result: We found that (i) sheep preferred Leymus chinensis and mixed subordinate species, cattle preferred Stipa grandis, and goat preferred Carex korshinskyi and Cleistogenes squarrosa. (ii) Consistent with these preferences, sheep increased the relative biomass of Stipa grandis, but reduced that of Carex korshinskyi; cattle reduced the relative biomass of Stipa grandis and Carex korshinskyi but increased that of mixed subordinate species; and goats reduced the relative biomass of Cleistogenes squarrosa and Carex korshinskyi but increased that of mixed subordinate species. (iii) Overall, grazing significantly increased ANPP, mainly due to an increase in ANPP of Leymus chinensis and subordinate species, at the cost of Stipa grandis. Conclusions: Summer grazing by different livestock species at moderate intensity can increase ANPP, while livestock forage preferences can drive divergent changes in species composition. Our results also imply that livestock composition can be used as a mean to manage vegetation dynamics. [ABSTRACT FROM AUTHOR]

Meadow steppes of Opillia (western edge of Podillia Upland, Western Ukraine) belong to xerothermic calcareous grasslands which are the most species-rich habitats in Europe. This paper contains results of a nine-year study (2010–2018 years) of plant species composition in ‘Ostrivets’ grassland after the cessation of traditional management (mowing). The patch had been burnt for at least five years running and then abandoned for five more years. The patch was chosen as a model grassland of abandoned meadow steppes. We examined plant species richness and composition on three sample plots of 5 x 5 m2. In 2010, at the beginning of annual burning practice the plots harboured 114 species. One year after cessation of disturbance by fire (2014), species richness decreased to 108 species. In 2018, after five years of abandonment it reached 83 species. Abundance of the dominant species (Brachypodium pinnatum) remained unchanged when the patch was under annual burning regime. After abandonment of the habitat Molinia arundinacea became the dominant species. Species composition experienced changed as well. Only 37.9% of species remained in the sample plots from 2010 till 2018. The proportion of meadow-steppe species halved, they were substituted by species of forests, forest edges and ruderal species. Percent of meadow species did not significantly change, however this group of species began to dominate within the community. The cover of woody vegetation reached 15–20% in 2018. Rubus caesius encroached on the grassland in 2014 and gained 20% of projective cover in 2018. Ten out of thirteen rare species disappeared from the habitat during the study period. ‘Ostrivets’ habitat requires urgent measures to be taken to restore and preserve meadow-steppe species composition. We suggest the following measures: elimination of trees and shrubs, regular moving and overseeding of extinct species.

The occurrence of multi‐year drought is predicted to increase globally with climate change. However, it is unclear whether drought effects on ecosystems are progressive through time.Here, we experimentally reduced growing season precipitation (GSP) by 45% at seven North American temperate grasslands for four consecutive years to determine the following: (a) whether the effects of reduced precipitation on plant community structure and biomass components (shoot, root, litter) are compounding over time; (b) whether prior year climatic and soil conditions influence subsequent drought impacts on plant community structure and biomass components; and (c) whether the effects of reduced precipitation on individual ecosystem components are related to one another.Across the seven field sites, we observed neither consistent nor progressive effects of reduced precipitation on any biomass component during the experiment, despite having extreme drought conditions imposed for four consecutive years. Relative to the ambient treatment, above‐ground net primary productivity (ANPP) declined in response to drought during the early years of the experiment but increased above the ambient treatment in the fourth year, while root and litter biomass were stable across the sites throughout the study. Similarly, graminoid cover decreased initially but recovered by the final year of the experiment, contributing to observed differences in species composition between treatments across sites. Compositional changes were not associated with any declines in species richness or evenness. Divergent responses among years were not driven by lag effects based on prior year climatic and soil conditions. Furthermore, precipitation effects on ecosystem components were largely independent as we found only two positive links: between ANPP and plant species richness, and between species evenness and composition.Synthesis. Overall, our results suggest that these northern grasslands are relatively resistant to short‐term multi‐year drought in the context of supporting plant diversity and biomass production. [ABSTRACT FROM AUTHOR]

Abstract Groundwater level is crucial for wetland plant growth and reproduction, but the extent of its effect on plant growth can vary along with changed precipitation and temperature at different seasons. In this context, we investigated the effect of two groundwater levels (10 cm vs. 20 cm depth) on growth and reproductive parameters of Carex cinerascens, a dominant plant species in the Poyang Lake wetland, during three seasons (spring, summer, and autumn) and during two consecutive years (2015 and 2016). Carex cinerascens showed low stem number, height, and individual and population biomass in summer compared to spring and autumn. 10 cm groundwater level was overall more suitable for plant growth resulting in higher stem height and biomass. However, the interactive effect between groundwater level and season clearly demonstrated that the effect of groundwater level on plant growth occurred mainly in autumn. After the withering of the plant population in summer, we observed that C. cinerascens growth recovered in autumn to similar values observed in spring only with 10 cm groundwater level. Consequently, we could deduce that lowering groundwater level in the studied Poyang Lake wetland will negatively impact C. cinerascens regeneration and growth particularly during the second growth cycle occurring in autumn. Additionally, our results showed that, independently of the season and groundwater level, population biomass of C. cinerascens was lower during drier year. Altogether, our findings suggest that water limitation due to both reduction in precipitation and decreased groundwater level during the year can strongly impact plant communities.

The field experiments were carried out during 2015-2018 in the Akmola region's dry-steppe zone, Northern Kazakhstan. The changes in plant species composition were studied to estimate the dynamics of successions in artificial pastures (AP) and partially artificial pastures (PAP) compared to Controls (natural grassland). All AP and PAP plots in all field experiments showed significant plant composition changes and pasture quality improvement compared to the Controls in two studied years. The succession dynamics were stable over the two years of study in field experiments, with a continual increase in the percentage of Poaceae grass species in AP and PAP. The replacement of significant species Agropyron pectinatum (M. Bieb.) P. Beauv to Festuca valesiaca Schleich. ex Gaudin was observed between AP and PAP in all three field trials. Pastures' biomass production, including fresh and dry weights and post-harvest plant and root remnants, were stable in each field trial over the two years. We concluded that pasture successions develop differently and depend on many factors, including the percentage of plant species and their composition and pastures' ability to recover after plant harvesting or grazing. [ABSTRACT FROM AUTHOR]

Semi-natural grasslands in Japan have decreased due to management abandonment and urbanization over the last 100 years, but they remain in suburban areas in addition to rural areas. Because suburban grasslands have various land-use histories and disturbance regimes, plant and herbivorous insect communities are likely to differ among grassland types. To identify grasslands with high conservation value, we conducted a comprehensive survey of grasshoppers and plants in 150 grasslands with 5 grassland types differing in land-use history and current management in northern Chiba prefecture, Japan. We then analyzed the association of the distributions of grasshopper and plant species compositions. Our results showed that grasshoppers were classified into habitat specialists and generalists. Three out of four habitat specialists were almost exclusively found in semi-natural grasslands and vacant lots, while habitat generalists were commonly observed at the cropland margins. This habitat specialist–generalist distribution gradient corresponded well to that found in plant communities, which was probably due to current disturbance regimes. We suggest that vacant lots as well as semi-natural grasslands have high conservation value for grassland organisms of various taxa in suburban areas, and grasshoppers are candidate indicator species for monitoring grassland environments. [ABSTRACT FROM AUTHOR]

Wetland restoration had been implemented for more than two decades in Sanjiang Plain, Northeast China. To assess the restoration efficiency of wetland vegetation, we investigated plants composition of community, plant species diversity and aboveground biomass of restored sites in a chronosequence of restoration (1, 2, 3, 6, 8, 11, 15 and 25 years) in the Sanjiang Nature Reserve. As comparison, we also investigated the same factors in a cropland and a natural marsh adjacent to the restored sites. The results showed that wetland plant species can invade quickly after croplands were abandoned when there were suitable hydrology conditions. On the early stage of the restoration, weeds were main plant species in the restored sites. Wetland species appeared at the same time but differed from the dominant species from the adjacent natural marshes. Common native wetland species could dominance the community after 3-year restoration. Species richness and diversity increased on the early stage, and then decreased to the similar level of the natural marsh with the extension of restoration. Plant biomass could restore easier than the species composition and diversity. Our results indicated that plant species composition and diversity of abandoned reclaimed wetlands can restore gradually by natural succession in Sanjiang Plain. However, 25-year restoration site had similarity index of only 56% with the natural marsh, which revealed that two decades are not enough for complete restoration of vegetation. [ABSTRACT FROM AUTHOR]

Question: The impact of ants on the vegetation and soil seed bank of alpine meadows on the Qinghai‐Tibetan Plateau is largely unknown. We questioned how the mound‐building ant, Camponotus herculeanus, affects the above‐ground vegetation, the soil seed bank and physico‐chemical properties of the soil. Location: An alpine meadow in the northeast margin of the Qinghai‐Tibetan Plateau (37°40′ N, 102°32′ E), China. Methods: We used field and greenhouse studies to determine the above‐ground vegetation parameters and soil physico‐chemical properties, and the soil seed bank composition under the mound (UM), the herbage circle at about 10 cm width around the outside of the mound (mound edge, ME) and the area 1 m from the center of the mound (control). Results: (a) The mound edge had higher vegetation height, greater above‐ground biomass, lower vegetation coverage and lower plant richness than controls; (b) Gramineae had a higher total importance value, which was based on the height, coverage and biomass of each plant species, and composed a higher biomass proportion in the mound edge than in controls (68% vs. 38%), while most of the perennial dicotyledons were restricted to the controls; (c) dicotyledons were the main seed group in the 0–8 cm layer of soilUM (43%), soilME (51%) and soilcontrol (60%), while Gramineae had a significantly higher seed density and percentage of total seeds in the soilUM (16,507 ± 2,882.7 seeds/m3, 28.1%) than in the soilcontrol (4,200 ± 799.5 seeds/m3, 10.2%); and (d) soil in the 0–8 cm layer under the mound had lower water content and lower bulk density than soil on the mound edge and in controls. Conclusions: Mound‐building activity of Camponotus herculeanus increased the proportion of Gramineae and decreased the proportion of dicotyledons at the site of the study indicating, that mound building could enhance the transformation of a grass and sedges community to mainly a grass community in the alpine meadow. [ABSTRACT FROM AUTHOR]

Plant biomass accumulation and productivity are important determinants of ecosystem carbon (C) balance during post-fire succession. In boreal black spruce (Picea mariana) forests near Delta Junction, Alaska, we quantified aboveground plant biomass and net primary productivity (ANPP) for 4 years after a 1999 wildfire in a well-drained (dry) site, and also across a dry and a moderately well-drained (mesic) chronosequence of sites that varied in time since fire (2 to ~116 years). Four years after fire, total biomass at the 1999 burn site had increased exponentially to 160 ± 21 g m⁻² (mean ± 1SE) and vascular ANPP had recovered to 138 ± 32 g m⁻² y⁻¹, which was not different than that of a nearby unburned stand (160 ± 48 g m⁻² y⁻¹) that had similar pre-fire stand structure and understory composition. Production in the young site was dominated by re-sprouting graminoids, whereas production in the unburned site was dominated by black spruce. On the dry and mesic chronosequences, total biomass pools, including overstory and understory vascular and non-vascular plants, and lichens, increased logarithmically (dry) or linearly (mesic) with increasing site age, reaching a maximum of 2469 ± 180 (dry) and 4008 ± 233 g m⁻² (mesic) in mature stands. Biomass differences were primarily due to higher tree density in the mesic sites because mass per tree was similar between sites. ANPP of vascular and non-vascular plants increased linearly over time in the mesic chronosequence to 335 ± 68 g m⁻² y⁻¹ in the mature site, but in the dry chronosequence it peaked at 410 ± 43 g m⁻² y⁻¹ in a 15-year-old stand dominated by deciduous trees and shrubs. Key factors regulating biomass accumulation and production in these ecosystems appear to be the abundance and composition of re-sprouting species early in succession, the abundance of deciduous trees and shrubs in intermediate aged stands, and the density of black spruce across all stand ages. A better understanding of the controls over these factors will help predict how changes in climate and fire regime will affect the carbon balance of Interior Alaska.

Abstract Slope aspect can affect soil temperature and soil type distribution, which, in turn, is likely to influence plant community composition. Three Qilian mountains, located in the northeastern part of the Qinghai–Tibetan Plateau, China, with four distinct slope aspects including south‐facing (SF), southwest‐facing (SW), northwest‐facing (NW), and north‐facing (NF) slope aspects, were studied to investigate the impact of slope aspect on plant assemblages. The results indicated that the environmental conditions were favorable under the NF and NW slope aspects as the soil water, soil organic carbon (SOC), and soil total nitrogen (STN) contents were significantly higher, and soil temperature (ST) and soil bulk density (SBD) were significantly lower than under the SF and SW aspects. Under all slope aspects, however, SOC, STN, and soil total phosphate in the top 0.2 m of topsoil accounted for about 60% of its total quantity, to a soil depth of 0.6 m. The plant communities on the SF and SW slopes were found to be primarily composed of Poa pratensis, Potentilla anrisena, and Carex aridula. In contrast, the plant community on the NW slope was mainly composed of Kobresia humilis, Carex crebra, and Potentilla bifurca, while on the NF slope it was mainly composed of Picea crassifolia, Carex scabrirostris, and Polygonum macrophyllum. The order of the influence of environmental factors on species distributions was ST > SBD > sand > STN. Results suggest that the slope aspect has an important role in the regulation of the soil environment and plant assemblages and that ST and SBD were the main factors influencing plant community composition. Furthermore, evidence from this study suggests that these mountains will become increasingly vulnerable to global warming. Thus, the plant community composition on these mountains must be monitored continuously in order to allow for strategic adaptive management.

Groundwater level is crucial for wetland plant growth and reproduction, but the extent of its effect on plant growth can vary along with changed precipitation and temperature at different seasons. In this context, we investigated the effect of two groundwater levels (10 cm vs. 20 cm depth) on growth and reproductive parameters of Carex cinerascens, a dominant plant species in the Poyang Lake wetland, during three seasons (spring, summer, and autumn) and during two consecutive years (2015 and 2016). Carex cinerascens showed low stem number, height, and individual and population biomass in summer compared to spring and autumn. 10 cm groundwater level was overall more suitable for plant growth resulting in higher stem height and biomass. However, the interactive effect between groundwater level and season clearly demonstrated that the effect of groundwater level on plant growth occurred mainly in autumn. After the withering of the plant population in summer, we observed that C. cinerascens growth recovered in autumn to similar values observed in spring only with 10 cm groundwater level. Consequently, we could deduce that lowering groundwater level in the studied Poyang Lake wetland will negatively impact C. cinerascens regeneration and growth particularly during the second growth cycle occurring in autumn. Additionally, our results showed that, independently of the season and groundwater level, population biomass of C. cinerascens was lower during drier year. Altogether, our findings suggest that water limitation due to both reduction in precipitation and decreased groundwater level during the year can strongly impact plant communities. [ABSTRACT FROM AUTHOR]

Questions: (a) In which ways do woody species encroachment and fire affect vegetation and seed bank composition, structure and diversity in Transylvanian dry grassland; (b) do native and non‐native woody species differ with respect to their impact on grassland community composition and structure; (c) is burning useful to control woody species encroachment; and (d) can soil seed banks contribute to the restoration of grasslands in Transylvania? Location: Transylvania, Romania. Methods: We collected data on vegetation and seed bank composition in 4 m2 plots in 16 shrub‐encroached grasslands and adjacent open grassland. Data were analyzed with regard to the impact of woody species encroachment (native vs non‐native) and fire on grassland vegetation and the seed bank using NMDS and LME models combined with ANOVA and Tukey contrast tests. Results: Encroachment was accompanied by a decrease in plant species diversity and altered microclimatic conditions. There was a lack of sufficient evidence for a difference in effect size between native and non‐native woody species on tested vegetation or seed bank parameters. While the effects of fire on vegetation were weak compared to encroachment, burning failed to reduce the cover of woody species sustainably. Grassland vegetation and the seed bank differed significantly in species composition and diversity, indicating a limited potential for restoration from the seed bank alone. Conclusions: To halt secondary succession in Transylvanian grassland sustainably, we suggest the establishment of a post‐fire management regime including the cutting of woody species and/or re‐introduction of grazing and mowing. Grassland restoration from the seed bank may be supported by the introduction of species from surrounding intact grassland. [ABSTRACT FROM AUTHOR]

Aim: Climate is an important factor controlling plant distributions. However, it is not yet fully understood how climate interacts with human impacts or whether the effects of these factors differ between native and alien species. Facing ongoing climate change and urbanization, we explore the effects of climate on plant species richness and composition across European cities. Location: Sixty cities in Western, Central and Southern Europe. Taxon: Vascular plants. Methods: Species presence was recorded in seven habitats in each city. Large‐scale climatic gradients were derived from 22 climatic variables using a partial principal component analysis that controlled for the effects of human population size and gross domestic product. The effects of climate and habitat type on the numbers of native and alien species were tested using linear mixed‐effect models. The native and alien compositional variation across cities and habitats was analysed using principal component analysis with variation partitioning. Results: The Mediterranean‐to‐temperate climatic gradient had a significant effect on species numbers across all habitats. The numbers of both native and alien species increased from the Mediterranean to temperate Europe. Within each city, the proportion of alien species decreased from highly urbanized to less urbanized habitats. Climate had a stronger effect on the composition of alien plants than on the composition of native plants. The native species composition especially changed from the Mediterranean to temperate cities and alien species composition also from oceanic to continental cities. Main conclusions: Urban native and alien species richness follow the pattern found for the whole European flora. Based on this observation, we suggest that the future shift of warm and dry conditions from the Mediterranean to the north that is expected under global change scenarios could affect richness and change the composition of European urban floras. However, this shift would not necessarily alter the proportions of aliens. [ABSTRACT FROM AUTHOR]

Aims: Long-duration drought can alter ecosystem plant species composition with subsequent effects on carbon cycling. We conducted a rainfall manipulation field experiment to address the question: how does drought-induced vegetation change, specifically shrub encroachment into grasslands, regulate impacts of subsequent drought on soil CO2 efflux (Rs) and its components (autotrophic and heterotrophic, Ra and Rh)? Methods: We conducted a two-year experiment in Inner Mongolia plateau, China, using constructed steppe communities including graminoids, shrubs and their mixture (graminoid + shrub) to test the effects of extreme-duration drought (60-yr return time) on Rs, Rh and Ra. Results: Our results indicated that extreme-duration drought reduced net primary production, with subsequent effects on Rs, Rh and Ra in all three vegetation communities. There was a larger relative decline in Ra (35–54%) than Rs (30–37%) and Rh (28–35%). Interestingly, we found Rs in graminoids is higher than in shrubs under extreme drought. Meanwhile, Rh declines were largest in the shrub community. Although Ra and Rh both decreased rapidly during drought treatment, Rh recovered quickly after the drought, while Ra did not, limiting the Rs recovery. Conclusions: This study suggests that plant species composition regulates several aspects of soil CO2 efflux response to climate extremes. This regulation may be limited by above- and below-ground net primary production depending on soil water availability. The results of this experiment address a critical knowledge gap in the relationship between soil respiration and plant species composition. With shrub encroachment into grasslands, total soil respiration is reduced and can partly offset the effect of reduction in productivity under drought stress. [ABSTRACT FROM AUTHOR]

Influence of climate change on the grassland phenology has attracted more and more attentions of ecologists. Although dozens of studies have been conducted, there have been few records examining the phenology differences of grasslands with different plant species compositions. Using continuous photography and image processing methods, this study examined seasonal vegetation cover dynamics of grasslands along a degradation gradient to clarify the influence of vegetation composition on the dynamics of vegetation cover during growing season. Our results revealed that phenological patterns of grasslands differentiated with their degradation status. Abandoned farmland (AF) and severely degraded grassland (SD) with most annuals and least climax species had the earliest start of growing season, while AF and extremely degraded grassland (ED) dominated by grasses had the earliest end of growing season. The start and end of growing season were strongly related to the relative cover of climax species and grasses. The results presented in this study support the possibility of using digital photography to capture the role of plant species composition on vegetation phenology in grasslands. [ABSTRACT FROM AUTHOR]

The vegetation of protected salt meadows along the Baltic coast is fairly well known; however, dandelions have been so far treated as a collective species. The aim of our study was to examine the microspecies diversity of the genus Taraxacum in Polish salt and brackish coastal meadows and to analyse soil property preferences of the dandelion microspecies identified. In addition, we analysed the relations between soil properties and vegetation patterns in dandelion-supporting coastal meadows (by canonical correspondence analysis). The salt and brackish meadows along the Polish Baltic coast we visited were found to support a total of 27 dandelion microspecies representing 5 sections. Analysis of vegetation patterns showed all the soil parameters (C:N ratio, organic matter content, pH, concentration of Mg, P, K, electrolytic conductivity of the saturated soil extract ECe) to explain 32.07% of the total variance in the species data. The maximum abundance of most dandelion microspecies was associated with the highest soil fertility, moderate pH values and organic matter content, and with the lowest magnesium content and soil salinity. The exceptions were T. latissimum, T. stenoglossum, T. pulchrifolium and T. lucidum the occur-rence of which was related to the lowest soil fertility and the highest salinity. In addition, several microspecies (T. leptodon, T. gentile, T. haematicum, T. fusciflorum and T. balticum) were observed at moderate C:N ratios and ECe. Four other microspecies (T. infestum, T. cordatum, T. hamatum, T. sertatum) occurred at the lowest pH and organic matter content. The information obtained increases the still insufficient body of knowledge on ecological spectra of individual dandelion microspecies, hence their potential indicator properties. [ABSTRACT FROM AUTHOR]

In this study, we examine the pattern of occurrence of Impatiens parviflora in Central European oak forests over time and its ecological requirements within these types of communities. Research was based on phytosociological data collected in 3776 relevés. A modified TWINSPAN algorithm were used to distinguish the groups of oak forests. The ecological preferences of the I. parviflora and studied communities as well as differences between invaded and non-invaded vegetation plots were analyzed using mean weighted Ellenberg indicator values (EIVs). Finally, both the temporal pattern of I. parviflora participation and changes in its coverage in the studied communities were analyzed. Our study confirmed a high adaptability of this species with respect to temperature, moisture, soil reaction and nutrients and determined its broad ecological optimum in oak forests. However, it also revealed both a greater sensitivity of some communities within Central European oak forests to the invasion of I. parviflora and differences in habitat conditions between invaded and non-invaded vegetation plots. This suggests that the habitat niche of I. parviflora within oak forests is not accidental. The analysis of temporal changes in the frequency of I. parviflora confirmed a 20% increase in relevés over the last 50 years. However, we did not identify any statistically significant rise in the coverage of I. parviflora in oak forests specifically during the studied period.

Abstract The composition of the greenline plant community is linked to the stability of riparian ecosystems. Cool season exotic grasses are invading native plant communities across the northern Great Plains, potentially compromising streambank stability and increasing the risk of erosion within riparian ecosystems. To determine how the species composition of the greenline community impacts stream type and the risk of streambank erosion, thirty five reaches across five watersheds were sampled to determine the dominant greenline vegetation. At each reach, a cross-section was sampled to determine stream type, greenline vegetation, and risk of streambank erosion. Channel types were delineated using Rosgen's classification of natural rivers. Canopy cover and composition was assessed using the line point intercept method along a 30.5 m transect in the greenline community. Plants recorded were grouped by their wetland indicator status for the central Great Plains. The Bank Erosion Hazard Index (BEHI) was used to assess the streams risk of erosion by calculating the difference between the bank height and bank full height, average plant rooting depth and density, bank angle degree, and the dominant texture of the bank material. Bank height ratio (BHR) was assessed as a measure of streambank stability and floodplain connectivity. A Nonmetric Multidimensional Scaling ordination was performed to analyze plant community influences. Analysis of the data determined that the most stable stream types (E and C channels), lower BEHI scores, and stable bank height ratios were associated with high amounts of litter and facultative wet species. In comparison, unstable F channels were associated with early successional species and bare ground. Sites with the higher BEHI scores were associated with greenlines comprised of upland and facultative upland and saline tolerant species. Late successional facultative wetland species were found to provide the most protection to intermittent streambanks. [ABSTRACT FROM AUTHOR]

Highlights • Post-fire, plant cover was higher in areas previously treated for fuel reduction. • Cover of perennial graminoids post-fire was a driving factor for total plant cover. • Cover was negatively correlated with tree basal area and canopy cover after fire. Abstract The greater than 200,000 ha Wallow Fire of May-July 2011 burned through mixed-conifer and ponderosa pine forests in Arizona and New Mexico in the southwestern U.S. This “mega-fire” set the stage for an opportunistic study to examine understory plant community responses to pre-fire fuel reduction treatments in areas dominated by dry mixed-conifer forests. In 2016, five years after the fire, we remeasured nine pairs of treated and untreated sites that were installed in 2012 and compared understory characteristics including species cover, richness and community composition. Native plant cover was significantly higher (20% total cover) in areas that were treated for fuel reduction before the fire compared with untreated areas (17% cover), despite the variability in fire severity and tree mortality. Non-native plant cover was not significantly different between treated and untreated units. Herbaceous understory cover was negatively correlated (p < 0.05) with total tree basal area and tree canopy cover in treated as well as untreated units, and positively correlated with tree mortality and basal area mortality in the untreated units. In the treated units, species richness and diversity were negatively (r = −0.62 to −0.63) correlated with insolation and elevation. Non-metric multidimensional scaling ordinations along with univariate results suggested that community composition was driven by increased insolation following loss of tree canopy. Cover of species that benefit from high light and warmer temperatures, such as some shrubs and perennial graminoids, increased from 2012 to 2016. Overall, fuel reduction treatments led to persistent increases in cover of native species, lending weight to the usefulness of hazardous fuel reduction treatments in promoting native plant cover. [ABSTRACT FROM AUTHOR]

Abstract: The realization that anthropogenic nitrogen (N) deposition is causing significant environmental change in many ecosystems has led to lower emissions of reactive N and deposition rates in many regions. However, the impacts of N deposition on terrestrial ecosystems can be long lasting, with significant inertia in the return of the biota and biogeochemical processes to baseline levels. To better understand patterns of recovery and the factors that may contribute to slow or no responses following declines in N deposition, we followed plant species composition, microbial abundance, N cycling rates, soil pH, and pools of NO3− and extractable cations in an impacted alpine ecosystem following cessation of 12‐yr experiment increasing N deposition rates by 0, 20, 40, and 60 kg N·ha−1·yr−1. Simulated N deposition had resulted in a tripling in the cover of the nitrophilic species Carex rupestris, while the dominant sedge Kobresia myosuroides had decreased by more than half at the highest N input level. In addition, nitrification rates were elevated, soil extractable magnesium (Mg2+) and pH decreased, and aluminum (Al3+) and manganese (Mn2+) were elevated at the highest N treatment inputs. Over the nine years following cessation of N additions to the impacted plots, only the cover of the nitrophilic C. rupestris showed any recovery to prior levels. Abundances of both bacteria and fungi were lower with N addition in both treatment and recovery plots. Rates of nitrification and pools of NO3− remained elevated in the recovery plots, likely contributing to the lack of biotic response to the cessation of N inputs. In addition, nutrient base cations (Ca2+ and Mg2+) and soil pH remained depressed, and the toxic metal cations (Al3+ and Mn2+) remained elevated in recovery plots, also potentially influencing biotic recovery. These results emphasize the importance of considering long‐term environmental impacts of N deposition associated with legacy effects, such as elevated N cycling and losses of base cations, in determining environmental standards such as the metrics used for critical loads. [ABSTRACT FROM AUTHOR]

Abstract: Effective river restoration aims for the recovery of ecosystem functions by restoring processes and connectivity to the floodplain. At the straightened lowland river Stör in northern Germany, a sequence of 15 new meanders was created in 2008, with wavelengths up to 70 m. The newly created areas within the meander bends range in size from 215 to 1,115 m2 and function as a series of 15 restored floodplain sites, which are subject to succession. After 7 years of restoration measures, we investigated the vegetation dynamics on the (a) restored floodplains and compared them with adjacent floodplain sites that were used as (b) low‐intensity grazed grassland or as (c) abandoned grassland. We analysed the species diversity, functional vegetation parameters, and plant communities of 200 plots within the floodplain area of the three floodplain types and of 246 plots at their river banks. Plant species diversity and composition differed with respect to restoration measure and site management. Restored floodplains revealed a higher coverage in species of wet grasslands and softwood forests and higher species diversity than abandoned grasslands. Grazed grasslands showed the highest species number and coverages of pioneer vegetation. The banks indicated fewer differences in species composition between floodplain types. The construction of restored floodplains revealed greater overall plant diversity due to promoting the development of typical floodplain vegetation. Shallow meanders with increased flooding intensity and the creation of a varying microreliefs are recommended as combined river/floodplain measures in order to foster processes and connectivity between valley components. [ABSTRACT FROM AUTHOR]

Abstract: Question: Climate change interacts with land use and introduces new pressures that trigger growing concerns about increasing vulnerability of the Eurasian steppes. However, it is not well known how increasing precipitation and atmospheric N deposition interact with the land use legacy to affect nutrient availability, plant species composition and therefore vegetation dynamics of the Mongolian Steppe. Location: Steppe in Xilin River Basin, Inner Mongolia, China. The mean annual precipitation is 343 mm with 60%–80% of it occurring during the plant growing season. Methods: We conducted a 6‐years (2005–2010) field experiment to manipulate N and water availability on sites experiencing two different historical stocking rates. Species composition, above‐ground biomass and plant N concentration were determined at both individual and community levels. Soil cumulative inorganic N and N mineralization rates were determined by laboratory incubation. Results: (1) Supplementary irrigation increased soil cumulative inorganic N and N mineralization rate, plant community N uptake, and the abundance of perennial species for the site with high historical stocking rate. In contrast, long‐term water addition decreased soil cumulative inorganic N and N mineralization rate, and did not change the plant community N uptake, but increased the abundance of Cleistogenes squarrosa as a species indicative of degradation for sites with moderate historic stocking rate. (2) Nitrogen addition increased soil cumulative inorganic N and N mineralization rate irrespective of grazing history under ambient precipitation, and resulted in a burst of annuals in moist years at both sites. Under supplementary irrigation, N addition increased soil cumulative inorganic N and N mineralization rate at the site with moderate historic stocking rate, but not at the site with high historical stocking rate, and increased the abundance of taller perennial species at both sites. Conclusions: Legacy effects of grazing greatly affect plant composition responses to increasing water and N availability. The effectiveness of N application in restoring heavily degraded sites in the Mongolian steppe depends on precipitation availability. In the face of increasing precipitation and atmospheric N deposition, resource managers should be prepared to cope with the different vegetation succession and recovery trajectories as a result of historical land‐use difference. [ABSTRACT FROM AUTHOR]

Net methane (CH4) flux across the ecosystem-atmosphere boundary is governed by two counteracting processes, CH4 oxidation and production. Recent research on CH4 cycling has focused on net CH4 fluxes, however, the separate processes of CH4 oxidation and production may vary at local scales and respond differently to environmental change. Here, we separate CH4 oxidation and production, measured as emission, in situ using CH4 oxidation inhibition combined with a novel in situ 13CH4 labeling experiment to determine the rate of soil oxidation of atmospheric CH4. The study was conducted in a subarctic heath ecosystem with three characteristic plant community types: moist mixed species heath, dry Carex-dominated heath, and wet Eriophorum-dominated fen. We further explored the projected climate change effects of increased temperature and enhanced leaf litter input. The CH4 oxidation inhibition experiment revealed significant potential CH4 emission despite net CH4 uptake. Total CH4 oxidation and potential CH4 emission rates differed significantly between plant communities, demonstrating high local-scale variation in CH4 fluxes. Climate treatments did not affect CH4 oxidation rates, however, warming tended to increase potential CH4 emission, indicating that climate change may affect oxidation and production rates asymmetrically. Near-surface soil oxidation of atmospheric CH4 was successfully traced using 13C stable isotope labeling in situ. CH4 oxidation rates ranged widely, yet preliminarily suggested some degree of substrate limitation. Accounting for the local-scale variation in CH4 fluxes and the relative importance of the separate processes of CH4 oxidation and production will contribute importantly to predicting changes in landscape-scale CH4 budgets and climate feedbacks. [ABSTRACT FROM AUTHOR]

As an important freshwater lake and wetland area with international significance in biodiversity conservation, Poyang Lake is facing increasing pressure from human activities, including prescribed fire. In the present study, two representative wetland plants from Poyang Lake ( Carex cinerascens and Artemisia selengensis ) were selected to determine their in situ regeneration success following a prescribed winter fire. Monitoring of plant growth and species composition was carried out monthly for one year following burn treatments. Results showed that significantly higher densities of both C. cinerascens and A. selengensis were observed in the spring. Moreover, the prescribed fire had little influence on the aboveground and belowground biomasses of C. cinerascens , whereas a significant effect on A. selengensis was observed. A smaller difference in dominance values of constructive species was detected between burned and unburned plots. However, a significant increase in biodiversity was found within the burned A. selengensis community in spring. In addition, there was little difference in plant traits and community characters found between burned and unburned plots after the flooding season. Our findings suggest that the water regime is the main driving factor in regulating the ecological process of Poyang Lake, and a single prescribed fire was not sufficient to change the plant community structure, although it did have a significant influence on biomass and species composition in the season following the fire. [ABSTRACT FROM AUTHOR]

The success of grassland biodiversity restoration schemes is determined by many factors; as such their outcomes can be unpredictable. There is a need for improved understanding of the relative importance of below-ground factors to restoration success, such as contrasting soil type and management intensities, as well as plant community composition and order of assembly., We carried out an 8-year mesocosm experiment across three locations in the UK to explore the relative and interactive roles of various above-ground and below-ground factors in the establishment of target species, to determine general constraints on grassland restoration. Each location had a series of mesocosms with contrasting soil types and management status, which were initially sown with six grasses typical of species-poor grasslands targeted for restoration., Over 5 years, sets of plant species were added, to test how different vegetation treatments, including early-coloniser species and the hemiparasite Rhinanthus minor, and soil type and management, influenced the establishment of target plant species and community diversity., The addition of early-coloniser species to model grasslands suppressed the establishment of target species, indicating a strong priority effect. Soil type was also an important factor, but effects varied considerably across locations. In the absence of early-coloniser species, low soil nutrient availability improved establishment of target species across locations, although R. minor had no beneficial effect., Synthesis and applications. Our long-term, multi-site study indicates that successful restoration of species-rich grassland is dependent primarily on priority effects, especially in the form of early-coloniser species that suppress establishment of slow-growing target species. We also show that priority effects vary with soil conditions, being stronger in clay than sandy soils, and on soils of high nutrient availability. As such, our work emphasises the importance of considering priority effects and local soil conditions in developing management strategies for restoring plant species diversity in grassland. [ABSTRACT FROM AUTHOR]

Boreal forests in western North America are considered to be resilient to wildfire disturbance, demonstrated by paleoecological evidence and adaptive regenerative traits possessed by many species. However, little is known about drivers of fine-scale temporal changes in understory communities in boreal forests immediately following fire. Knowledge of these changes, and their relationships with burn severity and pre-fire forest stand conditions, could help us determine recovery of forests as wildlife habitat. Such information is urgently needed in the face of climate warming-induced changes in fire frequency and severity. We used a high-quality, long-term dataset of annual measurements of understory vascular plant communities in sub-arctic boreal forest stands dominated by jack pine ( Pinus banksiana ), black spruce ( Picea mariana ), or a mix of the two in the Northwest Territories, Canada. Here, we describe the initial 10 years of annual post-fire understory plant community dynamics and assess the important drivers shaping understory composition during this critical period of post-disturbance community assembly. First, we determined the relative importance of burn severity, pre-fire forest type, bare ground, woody debris, and number of years post-fire on understory species richness and composition dynamics following fire. Second, we explored annual dynamics in these communities and determined if compositional change was directional and predictable over time. We found that pre-fire forest type, burn severity, bare ground, woody debris, and number of years post-fire were important predictors of post-fire species richness and composition. Pre-fire forest type explained the greatest variation in understory plant composition, followed by burn severity. Across forest types, most species established within 1–3 years following fire and initial species composition determined directional changes in composition. Our results suggest that targeting monitoring efforts in the years immediately post-fire may be sufficient to understand forest successional direction with respect to composition and the important drivers of those changes over the first decade post-fire. However, the recent and ongoing impacts of climate change in boreal regions of western North America leads to uncertainty surrounding the continued ability of these forests to demonstrate resilience under an altered fire regime so these interactions should continue to be considered across a range of forest types and burn severities. [ABSTRACT FROM AUTHOR]

The forests in the Spačva Basin are a complex of lowland forests in the region of Slavonia (eastern Croatia). The present state of the forests is strongly influenced by intensive exploitation and hydro-ameliorative activities carried out in the past. The aim of this study was to consider the extent of changes in species composition, and the extent of environmental changes in forest communities of the Spačva Basin in relation to research conducted between 1969 and 1971. The species composition of four communities (Carpino betuli-Quercetum roboris,Genisto elatae-Quercetum roboris aceretosum tatarici,andcaricetosum remotae, andLeucojo-Fraxinetum angustifoliae) is studied by comparing 41 old and 57 new relevés. Changes were estimated using ordinations (RDA, CCA, DCA) and changes in species frequency and cover. A general trend of moisture reduction was noticeable among all communities. All vegetation types are becoming floristically more similar. An increase in frequency and cover of flood intolerant woody species (such asCarpinus betulus,Cornus sanguinea,Tilia tomentosa,andAcer tataricum) as well as a decrease of vernal species related to wet habitats are particularly evident. The succession of all studied communities is resulting in loss of the mosaic community pattern characteristic of lowland alluvial forests. [ABSTRACT FROM PUBLISHER]

In many parts of the world, the magnitude and frequency of cold-season precipitation are expected to increase in the near future. This will result in an increased magnitude and duration of winter and spring flooding by rain-fed streams and rivers. Such climate-driven increases in flooding are likely to affect riparian plant communities, but future vegetation changes are hard to predict due to current lack of data. To fill this knowledge gap, we experimentally modified the hydrology of five streams across three countries in north-western Europe during late winter/early spring over a period of 3 years. We assessed the responses in riparian plant species richness, biomass, plant-available nitrogen and phosphorus and seed deposition to increased flooding depth (+18 cm on average at the lowest positions along the riparian gradient) and prolonged flooding duration (6 weeks on average). After 3 years of increased flooding, there was an overall decline in riparian species richness, while riparian plant biomass increased. Extractable soil nitrogen and phosphorus also increased and are likely to have contributed to the increased biomass. Increased flooding resulted in the arrival of more seeds of additional species to the riparian zone, thereby potentially facilitating the shifts in riparian plant species composition we observed. The results of our concerted experimental effort demonstrate that changes in stream riparian plant communities can occur rapidly following increased winter flooding, leading to strong reductions in plant species diversity. [ABSTRACT FROM AUTHOR]

Many mountain pastures consist of a mosaic of grassland and shrub communities. Ongoing changes in mountain agriculture have affected the balance between the two elements of the mosaic. In order to understand the consequences of these changes for ecosystem functioning, we studied patterns in vegetation, root structure and soil properties along transects of varying grassland-to-shrub proportions. Our hypothesis was that differences in the vegetation aboveground are accompanied by differences belowground, related to soil properties and depth. The research was conducted at a subalpine site in the Trentino region (South-eastern Alps), consisting ofNardus strictagrasslands alternating with shrub patches ofRhododendron ferrugineum. Our investigation showed that the composition of vegetation was mainly governed byR. ferrugineumcover and less by soil properties. Plant species richness peaked at low to intermediate degrees of shrub cover and composition between transects became more similar with increasing shrub cover. WhereR. ferrugineumcover was higher, Hemicryptophytes caespitosae were replaced by Nano-phanerophytes with consequences for belowground structures. At increasing shrub cover, root length density decreased, especially in the top soil, while root weight density remained stable and C content increased insignificantly. We discuss that theses structural changes along the gradient ofR. ferrugineumcover affect a number of ecosystem services. The presented evidence suggests that maintaining grasslands with a low cover ofR. ferrugineumbalances a number of services, namely plant species diversity, carbon stabilization in soil and the prevention of soil erosion. [ABSTRACT FROM AUTHOR]

Extensive hydrologic modifications in coastal regions across the world have occurred to support infrastructure development, altering the function of many coastal wetlands. Wetland restoration success is dependent on the existence of hydrologic regimes that support development of appropriate soils and the growth and persistence of wetland vegetation. In Florida, United States, the Comprehensive Everglades Restoration Program ( CERP) seeks to restore, protect, and preserve water resources of the greater Everglades region. Herein we describe vegetation dynamics in a mangrove-to-marsh ecotone within the impact area of a CERP hydrologic restoration project currently under development. Vegetation communities are also described for a similar area outside the project area. We found that vegetation shifts within the impact area occurred over a 7-year period; cover of herbaceous species varied by location, and an 88% increase in the total number of mangrove seedlings was documented. We attribute these shifts to the existing modified hydrologic regime, which is characterized by a low volume of freshwater sheet flow compared with historical conditions (i.e. before modification), as well as increased tidal influence. We also identified a significant trend of decreasing soil surface elevation at the impact area. The CERP restoration project is designed to increase freshwater sheet flow to the impact area. Information from our study characterizing existing vegetation dynamics prior to implementation of the restoration project is required to allow documentation of long-term project effects on plant community composition and structure within a framework of background variation, thereby allowing assessment of the project's success in restoring critical ecosystem functions. [ABSTRACT FROM AUTHOR]

Gardeners can consume a large proportion of total domestic water, depending on their garden type and gardening style. We calculated water requirements of gardens based on species composition and land cover, and determined whether they can be predicted from the socio-economic, demographic and cultural characteristics of households. We recorded the plant species composition, garden cover types, and household characteristics of 258 households in suburbs of the Mediterranean coast of Catalonia. The distribution of the 635 species in these gardens were the input to a cluster analysis, in which semi-natural gardens, vegetable gardens, lawn gardens and ornamental gardens formed strong floristic groups, with ornamental gardens predicted to require the least water inputs and lawn gardens the most. We conclude that only income and a lack of work were related to our water requirement variable, reflecting the expense of water and the propensity of the retired to spend more time in the garden. [ABSTRACT FROM AUTHOR]