Spoil Heaps From Brown Coal Mining: Technical Reclamation Versus Spontaneous Revegetation

Abstract Vegetation samples from either spontaneously revegetated or technically reclaimed spoil heaps of different ages in one of the largest active brown coal mining districts in Europe were analyzed and compared. The spoil heaps are located in the northwestern part of the Czech Republic and represent ages between 0 and 45 years. Ordination analysis (detrended correspondence analysis) showed that vegetation on technically reclaimed spoil heaps developed in a different way than that on spontaneously revegetated ones. The latter exhibited much higher species diversity in the oldest stages with the number of species doubled that of technically reclaimed sites. The oldest stages were also more advanced along an expected successional gradient as indicated by the ordination. Accelerating the vegetation development by technical reclamation was only of temporal character, whereas spontaneous succession proceeded further over the longer time scale. Spontaneous succession is advocated as an inexpensive and easy alternative to technical reclamation, because it leads to a more natural and rich vegetation cover. Unfortunately, technical reclamation is still the only approach considered in the present reclamation activities for this region.     

Restoration of alpine spoil heaps: Successional rates predict vegetation recovery in 50 years

Human disturbances in the alpine region can have long-lasting ecosystem effects because biological recovery in harsh environments proceeds slowly. As a by-product of the exploitation of hydroelectricity, surplus masses from tunnel excavations are deposited as spoil heaps in the alpine landscape. The typical management goal for such spoil heaps is that their species composition converges towards that of their undisturbed surroundings. At present we lack knowledge of the rate as well as the direction of these successions. We examined the species composition of five alpine spoil heaps in western Norway at two points in time, after 6-16, and 24-34 years of succession, with regard to vegetation cover, species richness, species composition and soil conditions. We also compared the vegetation of spoil heaps with that of their surroundings. After ca. 30 years, bryophyte and lichen cover and species richness were similar to those of their surroundings, while cover of vascular plants and species richness recovered more slowly. The vegetation development of spoil heaps appears safe-site limited rather than dispersal limited. Topsoil development was slow, but some accumulation of organic matter was observed. The species composition followed a successional trajectory in direction of the vegetation of the surroundings. Estimated linear successional rates indicate that 35-48 years are needed from construction of spoil heaps till a species composition more or less similar to their surroundings has been reached. However, these estimates are likely to be over-optimistic because successional rates tend to decrease with time. Based on our results we propose three changes to the current spoil-heap construction practice that will improve their restoration: (1) to increase surface unevenness, by which the number of safe sites will increase and germination and establishment success will be enhanced; (2) to increase substrate variability, by adding more of fine-grained materials more species will establish in shorter time; and (3) to use seed from local sources or to let the spoil heaps regenerate naturally.     

Succession pattern at two mineralogically different spoil heaps in Central Slovakia

Plants colonize post-mining areas such as spoil heaps even without human interference, by spontaneous succession. Knowledge of this process, its direction and role in shaping the vegetation is desirable not only from an ecological point of view but also in the application of remediation techniques of such environmental burdens. The aim of our study was to analyse plant species composition and to describe a succession pattern at two mineralogically different spoil heaps near the city of Banská Bystrica (central Slovakia). Hierarchical cluster analysis was used in PC-ORD software to classify physiognomic vegetation types (PVT) at heaps and synoptic tables were generated in Juice software according to species percentage of frequency and their median cover. At the Hg-heap Ve?ká studňa we recorded a total of 335 taxa of vascular plants and 83 taxa of bryophytes within 21 identified PVT, which were grouped into 4 clusters (forest, wetland, grassland and ruderal cluster). A total of 111 taxa of vascular plants and 76 taxa of bryophytes were recorded at the Cu-heap Podlipa and here 9 PVT formed 3 clusters (initial, non-forest and forest cluster). At both heaps PVT, represented as individual successional stages, formed a distinct continuum along the moisture gradient (in dry and wet areas). We can consider both heaps as species-rich with different diagnostic and constant species and a development of various microhabitats. In addition, bryophytes greatly contribute to species composition and richness and their assamblages in initial stages of succession can be important towards the higher ones.     

Ecological Design is More Important Than Compensatory Mitigation for Successful Restoration of Alpine Spoil Heaps

Spoil heaps of surplus rock from hydropower tunnel construction negatively impact alpine landscapes unless restored. Such spoil heaps have been created for more than 100 years, but we still lack knowledge about the relative importance of compensatory mitigation (seeding and fertilization), spoil‐heap construction method, local environmental factors, and regional climatic factors for restoration success. We studied the species composition of 19 alpine spoil heaps in Western Norway and their undisturbed surroundings using ordination and statistical modeling. Substrate grain size was the principal factor explaining differences in species composition between spoil heaps and their surroundings. Soil characteristics, that is, organic matter content and pH, and reutilization of topsoil were also important. Seeding and fertilization had negligible effects on restoration success. Slow recovery was observed for total vegetation cover and species richness of vascular plants and lichens while bryophyte cover recovered rapidly. Lower bryophyte cover and bryophyte and vascular plant species richness on older than on younger spoil heaps indicated recent changes in spoil‐heap construction practices that favor plant colonization. Our results indicate that spoil‐heap design is more important for restoration success than compensatory mitigation. We therefore suggest spoil heaps designed with a fine‐grained top substrate preferably from stockpiled local topsoil, with uneven surface topography that mimics natural topographic variation, and recommend discontinuation of seeding and fertilization.     

The vegetation of metalliferous and non-metalliferous grasslands in two former mine regions in Central Slovakia

We investigated the composition of the vegetation in two former mining regions in Central Slovakia: Banská Štiavnica with predominant Pb-Zn contamination and Staré Hory with a very high Cu content in the soil. Old heaps rich in heavy metals are covered with specific vegetation. On the Cu-rich spoil heaps, species-poor plant communities with prevailing Agrostis stolonifera, Avenella flexuosa, Acetosella vulgaris, Arabidopsis arenosa, Silene dioica, and S. vulgaris occur. Species such as Agrostis capillaris, Acetosella vulgaris, Arabidopsis arenosa, and Thlaspi caerulescens appear frequently on Pb-Zn mine wastes. Several differences in the vegetation structure were detected between the Pb-Zn and Cu mine heaps; higher amounts of vascular plants and fewer lichen species covered the Pb-Zn mine heaps. For the Cu mine heaps, on the contrary a small number of vascular species but a high number and coverage of lichen species, especially Ceratodon purpureus and Cladonia arbuscula subsp. mitis were typical. The non-metalliferous meadows in the vicinity of the mines showed uniform structure but a higher species diversity.     

Influence of vegetation regeneration and agricultural land use on lizard composition,taxonomic and functional diversity between different vegetation types in Caatinga domain,Brazil

Anthropogenic changes in habitats are one of the main threats to biodiversity. Understanding how species diversity and their functions are affected by these changes is crucial to assess environmental impacts. In this work, we aim to understand how lizard composition, taxonomic and functional diversity respond to differences in native vegetation regeneration stages (conserved vegetation and open secondary vegetation) and agricultural land use in different vegetation types (Caatinga sensu stricto, Cerrado sensu stricto and Relictual Humid Forest) in Caatinga domain, Brazil. In more degraded areas (open secondary vegetation and agricultural areas), we found a decline in species evenness, shown by greater dominance of few species. Moreover, we found a lower functional evenness in agricultural areas than in areas of conserved vegetation, which suggests that a smaller portion of functional traits present greater dominance in more anthropized areas. We did not detect any significant differences in species richness, but we did registered differences in species composition in Relictual Humid Forest. Contrary to our expectations, lizard abundance was also greater in more degraded areas, probably as a result of the increased abundance of species benefited by anthropization. In this work, we advance the knowledge of how anthropogenic changes influence lizard diversity and emphasize the importance of analysing different facets of diversity and different habitat environments to understand how anthropization affects patterns in community ecology.     

几种生态环境中AM真菌多样性比较研究

对渤海湾的海岛林地(IFL),黄河三角洲盐碱地(SAS)、鲁西南煤矿(CMS)和内蒙古退化草原(DGL)等几种生态环境中丛枝菌根(Arbuscular mycorrhiza,AM)真菌的多样性进行了调查。结果表明,在所调查的样点中,AM真菌的物种多样性不同,IFL中的最高,其次是SAS,CMS和DGL的最低。各地AM真菌种的丰度、孢子密度、频度、相对多度等也差异较大。这与各生态环境中的生态因子的差异相关。在总体上,Glomus属在各采样点出现的频度和相对多度最高,其次是Acaulospora属。但不同生态环境之问又存在差异,例如CMS中Acaulospora属的频度和相对多度比Glomus属的高。在IFL中,Gigaspora属的相对多度比Acaulospora属的高。各生态环境中的生态优势种不同,如在CMS中是A．mellea,在IFL和SAS土壤中却分别是G．margarita和G．caledonium,而DGL中各个种的分布却较均衡。     

A tale of two green walls: a functional trait approach to assess vegetation establishment on restored steep slopes

Green walls (GWs) have been increasingly recognized as an important restoration technique for steep slopes resulting from quarrying activities or major infrastructure construction projects. In practice, GW irrigation is considered essential, although studies evaluating vegetation establishment under different irrigation regimes are lacking. Besides taxonomic metrics, functional diversity measures were used to compare the diversity and composition of plant communities of two hydroseeded GWs, with different irrigation regimes (irrigated vs. low‐irrigated). The studied GWs were installed in Peneda‐Gerês National Park (NW Portugal) to minimize the visual impact of shotcrete walls, along a road infrastructure, and promote their ecological restoration. Species' cover was recorded 3 years after installation. Species were classified according to their growth form, life form, and life strategy. Despite hydroseeding approximately 57 species, GW vegetation was dominated by spontaneous species, particularly acrocarpous mosses, regardless of irrigation regime. Species and functional richness were higher under irrigated conditions, while no differences were observed for species diversity and functional dispersion. Functional trait composition did not differ between GWs, indicating that both systems potentially provide the same ecosystem functions and services. Our results also suggest that spontaneous species colonizing GWs are highly adapted to local environmental conditions, given their dominance in both irrigated and low‐irrigated communities. Overall, irrigation did not affect the structure and functioning of GW communities, only their redundancy, since more species exhibiting similar traits were established in the irrigated GW. Therefore, our findings suggest that low‐irrigated GWs, hydroseeded with native species, represent a more cost‐effective solution to reduce the ecological impacts of steep slopes.     

Plant functional group removal alters root biomass and nutrient cycling in a typical steppe in Inner Mongolia, China

Loss of functional diversity has been demonstrated to have a variety of impacts on ecosystem functioning. However, most studies have been implemented in artificially assembled communities by removing the original vegetation and seeding with desired species or functional group compositions. Such approaches could significantly disturb belowground biomass, especially roots, making it difficult to examine belowground responses to diversity manipulations. To circumvent this issue, plant diversity gradients were established by in situ removal of aboveground biomass of different plant functional groups (PFGs) in a typical steppe, and belowground processes related to roots and soil were examined. Root nutrient pools exhibited contrasting patterns, with the phosphorus (P) pool decreasing linearly upon increased PFG removal while the nitrogen (N) pool had a hump-shaped response. Soil NO^3? increased while net N mineralization decreased with PFG removal. In contrast, soil P showed little response to PFG removal. Furthermore, both the identity and number of PFG removed had a significant influence on root and soil properties. The results of this study showed that loss of a combination of PFGs was important in natural grassland, and an approach with minimal influence on belowground processes is promising in studying diversity loss effects in natural ecosystems.     

Biodiversity responses to vegetation structure in a fragmented landscape: ant communities in a peri-urban coastal dune system

Habitat fragmentation often results in significant degradation of the structure and composition of remnant natural vegetation, leading to substantial biodiversity decline. Ants are an ecologically dominant faunal group known to be sensitive to vegetation degradation following fragmentation. We examined ant diversity and composition in relation to changes in vegetation structure in remnant coastal vegetation in the global biodiversity hotspot of southwestern Western Australia. The key features of vegetation structure driving the species and functional diversity and composition of ant communities were measures of cover of vegetation and bare ground. However, these effects were highly idiosyncratic at the species level. Cluster analyses based on plant species composition classified plots into two groups corresponding to relatively intact and degraded vegetation respectively. Although systematic changes in plant diversity and vegetation structure were observed between the two groups, key features from an ant perspective (native plant cover and bare ground) remained unchanged. Vegetation degradation consequently had little overall effect on ant species composition and functional diversity. The major disturbance–related impact on ant communities was through invasion by exotic ants, especially Pheidole megacephala; however, this occurred only in close proximity to development. Our results suggest that the priority for conserving ant diversity in our coastal dune system is the prevention of invasion by exotic species.     

Taxonomic and functional approaches reveal different responses of ant assemblages to land-use changes

Land-use change is well documented to cause species loss. However, our understanding of the effects of land-use change on other aspects of biodiversity is still limited. We evaluated if different land-use changes (Eucalyptus plantation and planted pasture) affect ant species and functional groups in similar ways across three Cerrado vegetation types (grassland, savanna and savanna-forest). We found that ant species and functional responses differed with land-use change in relation to frequency of occurrence and habitat specificity and fidelity. Land-use change affected species frequency of occurrence but not functional groups, indicating that species are more sensitive than functional groups to habitat transformation. Native habitats had different indicator species and functional groups compared with converted habitats. However, we did not find functional group indicators of converted habitats in any vegetation type; indicating that there is no specificity and fidelity of functional group to converted habitats and that such an approach is less sensitive to land-use changes. In savanna and savanna-forest, species and functional groups showed the same response in relation to composition with differences between native and converted habitats. Thus, functional groups will be lost when ant species are lost. In grasslands, functional group composition was similar between native and converted habitats indicating a turnover of species within functional groups. We demonstrate that both Eucalyptus plantation and planted pasture affect ant species and functional groups in different ways, with negative impacts both taxonomically and less so functionally. Therefore, we show that the two aspects of biodiversity can respond independently to land-use changes and, hence, the importance of using both taxonomic and functional group approaches to evaluate the effects of land-use change on biodiversity in savanna systems.     

Soil Properties and Species Richness of Invertebrates on Afforested Sites after Brown Coal Mining

Variation in soil properties may influence diversity of invertebrate communities, a crucial component of every ecosystem, and their impact should be considered also in restoration management. Although most spoil heaps have been reclaimed after brown coal mining, some post‐mining sites are left to natural succession. Little is known, however, about the effects of these two fundamentally different approaches on diversity of invertebrates inhabiting these stands. While controlling for habitat characteristics, we analyzed the effects of soil properties on species richness of seven invertebrate groups representing various trophic levels and diverse spatial niches at afforested spoil heaps and adjacent pits managed under these two basic restoration approaches in the North Bohemia Brown Coal Basin (Czech Republic, central Europe). Forty‐seven percentage of 140 invertebrate species occurred on both reclamations and successions, but many were found exclusively on successions (37%) or reclamations (16%). The species richness of various groups was affected by different soil properties either independently of other variables or in interaction with microclimatic conditions or management history. These results imply a need for diverse management approaches in post‐mining areas to support the diversity of invertebrate communities. Technical reclamations with artificial plantations and spontaneous forest development on bare substrate (thus creating mosaics of open patches and afforested stands with different soil deposit materials) were found to be reasonable alternatives to support invertebrate richness on post‐mining forested stands. We conclude that these two approaches should properly be combined in practice.     

Climate and pH as determinants of vegetation succession in Central European man‐made habitats

Questions: (1) What are the most important abiotic environmental variables influencing succession in central European man‐made habitats? (2) How do these variables interact with one another and with variation in community properties? Location: Central, western and southern parts of the Czech Republic. Habitats included old fields, urban sites, spoil heaps after coal mining, sites at water reservoirs, extracted sand pit and peatland and reclaimed sites in areas deforested by air pollution. Methods: We investigated vegetation patterns on 15 succes‐sional seres, sampled by the same methods. Time of succession over which the data were available ranged from 12 to 76 years. The cover of vascular plant species (in %) was estimated in 5 m × 5 m plots. The relationships between vegetation characteristics (species composition, total cover, cover of woody species, species number and rate of dominant species turnover) and 13 abiotic site factors, including climatic and soil variables, were tested using CCA ordination and regression models. Results: Substratum pH, the only substratum characteristic, and climate were the environmental variables significantly affecting the vegetation patterns in the course of succession. The rate of succession, measured as the turnover of dominant species, was significantly more rapid in lowland than in mountain climates. On alkaline soils, species numbers in succession increased towards warmer climates. However, acid soils prevented any increase in species numbers, regardless of the climate. Surprisingly, forms of nitrogen and contents of C, P and cations did not exhibit any significant effect on the vegetation characteristics studied. Conclusions: Our approach, to compare a number of seres, can contribute not only to our understanding of succession, but also to help restoration projects to predict vegetation change because the crucial environmental variables, as identified by this study, are easy to measure.     

An Evaluation of Reclamation Success on Idaho's Phosphate Mines

To evaluate reclamation success on the Wooley Valley phosphate mine in southeastern Idaho, we compared vegetation structure and soil physical, chemical, and elemental properties of several different reclamation treatments with those of a nearby reference area (a native Artemisia tridentata vaseyana/Festuca idahoensis association) after 14 years. Vegetation data had been collected four years after reclamation, and we were able to compare differences in biomass and species composition between dates on the reclaimed area. Four years after reclamation there were no differences in total biomass between topsoil or spoil or between seed only, seed + mulch, or control treatments on the different soil types. Most treatments were dominated by seeded perennial grasses. Fourteen years after reclamation there were no differences in biomass or cover between spoil and topsoil plots, but on spoil plots the seeded and mulched treatment had higher total biomass and vegetation cover than on control or seed-only treatments. The seeded perennial legume Medicago sativa was codominant with the seeded forage grasses on all of the treatments. High initial fertilization rates probably facilitated the early establishment and dominance of the forage grasses; once nutrient levels, especially nitrogen, began to decline, the legume increased in abundance. Similarity between the reclaimed area and the reference or native area was low. Reclaimed treatments had higher biomass but lower species richness. The topsoil and spoil plots had similar soil texture, bulk density, pH, cation exchange capacity, electrical conductivity, and phosphorus. Differences in organic carbon, total nitrogen, carbon: nitrogen ratios, and available moisture were related more to treatments than to soil type. High biomass and, thus, litter input on the seed + mulch treatment on spoil plots resulted in both higher OC and TN than any on other soil/treatment combination. The reclaimed area had lower OC, TN, and available moisture than did the reference area on all but seed + mulch spoil plots. Bulk density was higher on reclaimed plots. The long-term differences observed between the reclaimed and reference areas parallel those obtained for other western reclamation sites. Although successional trajectories depend on the attribute measured, similarity to native reference areas depends on the initial reclamation methods. We discuss reclamation methods that would increase the structural and functional similarity of reclaimed and reference areas on the Wooley Valley phosphate mine.     

Floristic composition and diversity changes over 60 years in eastern mulga communities of south central Queensland,Australia

Botanical surveys from prior to 1949 documented the plant species composition of the mulga (Acacia aneura) communities in the eastern Mulga Lands Bioregion of Queensland, Australia. These surveys recorded 282 vascular plant species including 268 natives and 14 exotics. Since 1949, mulga communities have experienced considerable modification through continuous grazing by domestic sheep and cattle even during drought periods and extensive vegetation clearance. To increase our knowledge on floristic composition and diversity change over this time, floristic data were recollected from mulga communities in the same region between 2007 and 2010 using a more systematic procedure. These surveys recorded 292 vascular plant species including 269 natives and 23 exotics. Species richness and composition within five life forms: tree, shrub, vine, forb and graminoid were compared between the recent survey data and the historical survey data. The majority of native plant species were either in the forb (45.4% of total native species) or graminoid (25.7% of total native species) life forms over the 60-year period. There was no significant difference in species richness between the historical and recent surveys within tree or shrub life forms, but there were differences in species richness in vine, forb and graminoid life forms over time. Similarities in native species between the historical and recent surveys were high. Sorensen Similarity Indices (ISS) were: 0.77 at species level, 0.84 at genus level and 0.87 at family level. In contrast, the similarity indices for exotic species was low (0.59) for species and genera (0.61), but high for families (0.86). More exotic species were recorded recently than historically. Among these, buffel grass (Pennisetum ciliare) and colocynth (Citrullus colocynthis) were more commonly encountered than other exotic species in the eastern mulga communities of south central Queensland, Australia.     

Land use change has stronger effects on functional diversity than taxonomic diversity in tropical Andean hummingbirds

Land use change modifies the environment at multiple spatial scales, and is a main driver of species declines and deterioration of ecosystem services. However, most of the research on the effects of land use change has focused on taxonomic diversity, while functional diversity, an important predictor of ecosystem services, is often neglected. We explored how local and landscape scale characteristics influence functional and taxonomic diversity of hummingbirds in the Andes Mountains in southern Ecuador. Data was collected in six landscapes along a land use gradient, from an almost intact landscape to one dominated by cattle pastures. We used point counts to sample hummingbirds from 2011 to 2012 to assessed how local factors (i.e., vegetation structure, flowering plants richness, nectar availability) and landscape factors (i.e., landscape heterogeneity, native vegetation cover) influenced taxonomic and functional diversity. Then, we analyzed environment – trait relationships (RLQ test) to explore how different hummingbird functional traits influenced species responses to these factors. Taxonomic and functional diversity of hummingbirds were positively associated with landscape heterogeneity but only functional diversity was positively related to native vegetation coverage. We found a weak response of taxonomic and functional diversity to land use change at the local scale. Environment‐trait associations showed that body mass of hummingbirds likely influenced species sensitivity to land use change. In conclusion, landscape heterogeneity created by land use change can positively influence hummingbird taxonomic and functional diversity; however, a reduction of native vegetation cover could decrease functional diversity. Given that functional diversity can mediate ecosystem services, the conservation of native vegetation cover could play a key role in the maintenance of hummingbird pollination services in the tropical Andes. Moreover, there are particular functional traits, such as body mass, that increase a species sensitivity to land use change.     

Relationship between land uses and diversity of dung beetles (Coleoptera: Scarabaeinae) in the southern Atlantic forest of Argentina: which are the key factors?

The loss of natural habitats is one of the main drivers of biodiversity decline. Anthropogenic land uses preserving biotic and abiotic conditions of the native ecosystem are more suitable to preserve the native biodiversity. In this study, we explored changes in species richness and composition in different land uses of the southern Atlantic forest, considering three independent factors: (1) canopy (presence–absence), (2) type of vegetation (native–exotic) and (3) livestock (presence–absence). We expected a gradient of response in the richness and composition of the native forest dung beetle community, from land uses preserving canopy and native vegetation to open land uses with exotic vegetation. Dung beetles were sampled in protected native forests and four land uses, using two potential food resources: human dung and carrion. The species richness and composition of each habitat, as well as differences in composition and the influence of factors over diversity, were then analyzed. As expected, our results showed that land uses preserving canopy and native vegetation maintain the dung beetle diversity of the native forest. Moreover, while the three factors analyzed influenced dung beetle diversity, canopy cover was the main driver of dung beetle diversity loss. The main conclusion of this study is that the conservation of canopy (either native or exotic) is determinant to preserve highly diverse dung beetle communities and subsequently, the ecological functions performed by this taxon. However, the ecophysiological mechanism behind the response of dung beetles to habitat disturbance is poorly understood.     

The distribution and habitat associations of non‐native plant species in urban riparian habitats

Questions: 1. What are the distribution and habitat associations of non‐native (neophyte) species in riparian zones? 2. Are there significant differences, in terms of plant species diversity, composition, habitat condition and species attributes, between plant communities where non‐natives are present or abundant and those where non‐natives are absent or infrequent? 3. Are the observed differences generic to non‐natives or do individual non‐native species differ in their vegetation associations? Location: West Midlands Conurbation (WMC), UK. Methods: 56 sites were located randomly on four rivers across the WMC. Ten 2 m × 2 m quadrats were placed within 15 m of the river to sample vegetation within the floodplain at each site. All vascular plants were recorded along with site information such as surrounding land use and habitat types. Results: Non‐native species were found in many vegetation types and on all rivers in the WMC. There were higher numbers of non‐natives on more degraded, human‐modified rivers. More non‐native species were found in woodland, scrub and tall herb habitats than in grasslands. We distinguish two types of communities with non‐natives. In communities colonized following disturbance, in comparison to quadrats containing no non‐native species, those with non‐natives had higher species diversity and more forbs, annuals and shortlived monocarpic perennials. Native species in quadrats containing non‐natives were characteristic of conditions of higher fertility and pH, had a larger specific leaf area and were less stress tolerant or competitive. In later successional communities dominated by particular non‐natives, native diversity declined with increasing cover of non‐natives. Associated native species were characteristic of low light conditions. Conclusions: Communities containing non‐natives can be associated with particular types of native species. Extrinsic factors (disturbance, eutrophication) affected both native and non‐native species. In disturbed riparian habitats the key determinant of diversity is dominance by competitive invasive species regardless of their native or non‐native origin.     

Impact of alien species on dune systems: a multifaceted approach

We applied a multifaceted approach, in terms of taxonomic, phylogenetic and functional diversity, to study at fine scale how three plant communities occurring in a Mediterranean dune have been affected by the encroachment of alien species. We sampled 81 sites in a Site of Community Importance in Central Italy. Past and present land use/cover data have been derived using GIS and remote sensing tools. Information on plants phylogenesis and functional traits has been gathered from several databases. Ecological variables have been collected. GLMs in conjunction with an Information Based approach were used to model species composition, richness and phylogenetic diversity. Multivariate analysis has been used to study functional diversity. The results outlined how total species richness is related to recent land transformations and to a set of environmental factors. The analyses of functional and phylogenetic diversity support the idea that alien species significantly affect the functional and phylogenetic characteristics of the native plant communities. Habitat filtering seems to be predominant in not-invaded plots, whereas limiting similarity/niche differentiation is predominant in driving community assembly of invaded communities. The attained scenario depicts the spread of a reduced group of alien species phylogenetically and functionally well-differentiated, able to reduce the abundance of native species, not to exclude them though. Ultimately, the multifaceted approach assisted in understanding the community assembly of dune vegetation, and to discern the relative impact of alien species on native plant communities. Such approach represents a crucial step to achieve an efficient management of dune habitats, as useful tool to monitor and to effectively protect their biodiversity and functioning.     

Do not neglect surroundings in restoration of disturbed sites

We examined the influence of surroundings, i.e. proximity effects, on the course of spontaneous vegetation succession using two data sets. In the first data set, we tested the effects of surrounding vegetation (woodlands, wetlands, grasslands, and synanthropic) on succession in various disturbed habitats in the Czech Republic by comparing successional sites with more natural vegetation within 100 m and at 1 km from each site. The habitats included old fields, gravel‐sand pits, spoil heaps from black coal mining, industrially extracted peatlands, and acidic stone quarries. We found that, with the exception of wetlands, the influence of the vegetation types on seral vegetation was nearly always significant using marginal and partial Canonical Correspondence Analyses. In the second data set, which included 27 limestone quarries, we compared species lists outside (up to 100 m apart) and inside the quarries using Detrended Correspondence Analysis and the Sørensen similarity index. We found much higher species similarity between outside and inside particular limestone quarries than among the quarries themselves and among their surroundings, which also indicates that the seral vegetation is decisively influenced by the surroundings. We argue that restoration ecologists should carefully consider the nature of the surroundings of disturbed sites because of its profound impact on restoration processes. They should conduct inventories and prescribe some restoration measures not only inside a restored site, but also in its surroundings.