Spontaneous Succession Research Articles

Restoration of soil-vegetation cover and soil microbial community at the Pechurki limestone quarry (Leningrad region, Russia)

Abstract Due to a significant increase in mining activity and subsequent ecosystem disturbances, it is becoming increasingly important to understand how degraded, unproductive quarries can be converted into new, self-sustaining communities that develop into natural environments. Former limestone quarry was investigated with aim to determine the best reclamation practice for surfaces of former lime rock quarries. Effects of spontaneous succession and forestry reclamation restoration approaches on vegetation and soil features were studied. The study was conducted in one of the largest limestone quarries of the Leningrad region, south taiga region. Species composition and vegetation cover were estimated for different plant communities within each ecotype of the quarry. Also soil characteristics were evaluated at each plot. We found that the main differences between plots were due to their position in the landscape; the most similar communities colonize similar ecotypes. On flat landforms, biodiversity is reduced under biological reclamation. At the sites under spontaneous succession, the level of biodiversity increases. In terms of biodiversity conservation and economic benefit, spontaneous succession is preferable to forestry reclamation for the restoration of carbonate substrates. After examining CO2 emissions from the quarry as a result of weathering of carbonates and soil respiration, as well as the level of CO2 sequestration from the atmosphere, we show that the establishment of certain landscape forms within former quarries can help to reduce atmospheric CO2.

Differences between primary and secondary plant succession among biomes of the world

Abstract Successional theory lacks an explicit, conceptual integration across types of disturbances and biomes. Most successional research addresses site‐ or process‐specific questions, but extrapolation of the findings to broad scales is limited. Studies of plant succession are often distinguished by the severity of the disturbance that triggers them (severely disturbed: primary; less severely disturbed: secondary). Here, we examine the common assumption that primary and secondary succession differ. We use two anthropogenic disturbances for this comparison, mining and ploughing. Successional generalizations are confounded by a complexity of environmental factors including climatic and geographic variation. We address these issues by contrasting succession across multiple biomes. We selected 166 studies of succession on mining sites (n = 73) or abandoned fields (n = 93) that allowed us to compare successional trajectories in terms of the likelihood of a return to target vegetation, changes in species richness, type of trajectories, and the importance of alien species. Success of both types of succession (a return to target vegetation) differed significantly among biomes, with more likely success in cold than warm biomes (for both primary and secondary seres) and in humid than arid biomes (primary seres only). Primary seres were also more likely than secondary seres to have increases in species richness, a predominance of divergent trajectories, and a lower likelihood that alien species influenced succession. Synthesis. The probability of reaching target vegetation by spontaneous succession is generally greater in biomes at higher versus lower latitudes. Primary and secondary seres differed regarding species richness, trajectories, and the role of alien species. Our results highlight that broad generalizations about succession are possible, despite a paucity of comparable data and our use of only two types of anthropogenic disturbances. Any generalizations that might be found among seres across disturbances and biomes will provide a practical framework for land managers to guide restoration efforts, particularly in poorly studied areas.

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 Banska 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 Veľka 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.

The role of dead standing biomass of Calamagrostis epigejos in nutrient turnover during spontaneous succession

Here we explore the idea that keeping dead standing (marcescent) biomass plants can reduce its nutrient (N, P) content. Later after biomass falling to ground this may result in substantial changes in nutrient turnover with consequences for plant competitive interactions.To explore the effects standing dead biomass we used Calamagrostis epigejos as a model species. It is a common expansive grass, which after senescence retain a large proportion of the plant remains as dead standing biomass. We determined the biomass, N and P concentrations of living biomass, standing dead biomass, and lying dead biomass at young and old successional sites on the post-mining heap near Sokolov. Further, we analyzed nutrient budget in dead biomass during decomposition and we compared it with nutrient budget in decomposing cellulose.Concentrations of N and P in living biomass were highest in April and decreased during season. Lying dead biomass had a higher N concentration than N concentration contained in standing dead biomass. A litterbag experiment revealed that N was released from lying dead biomass but accumulated in standing dead biomass during decomposition. Similarly the N was accumulated in decomposing cellulose. This accumulation was highest in sites with low decomposition rate. In late summer and autumn lying biomass was derived from senescence plants, came to soil and N was released during decomposition potentially usable for C. epigejos. Standing dead biomass turned to lying biomass during winter and spring and then during its decomposition N was immobilized from soil. This mechanism could reduce availability of N for other plants and increase competitive advantage of C. epigejos regrowing from belowground organs during spring.

Diversity of Ant Community in Ore Sedimentation Basin under Different Regimes of Reclamation

Post-industrial sites form a unique phenomenon in the landscape. They enable us to study the human-altered succession of communities. Regarding this, we studied an ant community in three types of habitats – reclamation and spontaneous succession in an ore basin together with unaltered surroundings in the Czech Republic. More than 30 years after being abandoned, the site with spontaneous succession was more species rich than the reclaimed one. Moreover, spontaneous succession created a habitat that was more similar regarding ant diversity to the unaltered surrounding environment than that after traditional reclamation. Ants dependent on tree vegetation were rather rare in both the reclaimed and spontaneous succession parts of the ore basin compared to the surrounding landscape. The relative abundance of socially parasitic ants increases in a gradient from the reclaimed basin, through the basin with spontaneous succession to the unaltered surroundings. Our study highlighted the fact that the formation of ant communities at post-industrial sites is clearly more complicated than for other arthropods, including related aculeate hymenopterans. The potential of both reclaimed and spontaneous succession basins for harbouring endangered species appeared to be lower for ants than for other taxa indicated by recent studies.

Changes in forest soil organic matter quality affected by windstorm and wildfire

Windthrows and fires are major natural disturbances in forest ecosystems, which can affect organic matter in the surface and the mineral layer of forest soil. The main aim of this study was to evaluate the changes occurring in the structure and properties of humic acid (HA) in the lands where windthrows and wildfires occurred. In November 2004, the forest in the area of 12,000 ha in the Tatra National Park, Slovakia, was seriously damaged by northern wind gusts exceeding 200 km/h. In July 2005, a wildfire broke out in a 220 ha of wind-damaged area. The HAs have been isolated from four research plots: (a) the area where the fallen trees were removed (EXT); (b) an area after windstorm covered by wood from struck trees (NEX), left for spontaneous succession; (c) an area after extracted timber, damaged by the surface wildfire (FIR); and (d) a reference intact spruce forest area (REF). Changes in the chemical structure of the HAs isolated from the research plots were determined on the basis of elemental analysis and UV-Vis, EPR, IR, and 13C NMR spectroscopy. All used analytical methods showed a decrease in the humification degree of the humic acids extracted from the soils where the spruce forest has been affected by a wildfire and a windthrow. In the case of the control sample HA (REF), the calculated atomic H/C and O/C ratios and the degree of aromaticity (α) calculated from the 13C NMR spectra were higher, indicating higher aromaticity of HA from the REF area. The more complex and developed structure of REF HA was confirmed by the higher value of E1%6 and the lower E4/E6 ratio obtained using UV-Vis spectroscopy. Also, the higher g-parameters determined from the EPR spectra of the stable radicals present in HA confirmed the lower aromaticity on the plots that have been subjected to the calamities. The 13C NMR spectra and the elemental analysis show that the structure of the HA extracted from the NEX plot is the closest to the REF. The results of the systematic research showed significant changes in the structure of HA taken from spruce forest soils that were subjected to windstorms and fires. An enrichment of the HAs in aliphatic carbon and so a lower humification degree of the organic matter in the areas calamity-affected were observed. The results clearly indicate that the HAs extracted from the disturbed plots of the spruce forest are not as stable as those extracted taken from the control plot.

Colonization of woodland species during restoration: seed or safe site limitation?

A strategy of assisted natural regeneration uses selective restoration interventions to remove potential barriers to passive natural regeneration and succession toward target ecosystems. In woodland restoration, this may involve the planting of woodland clusters that serve as seed sources for further colonization and/or site amelioration to enhance colonization and growth of the target species. We tested the importance of seed and safe site limitations for the colonization of birch and willows in experimental treatments representing a matrix of revegetation (+/−) and planted birch and willow clusters (+/−) on an eroded area in South Iceland. The revegetation was initiated in the fall of 1999 and clusters of birch and willows planted in 2002. Density of birch and willow seedlings and their distribution among microsites was surveyed in 2005, 2006, 2010, and 2015. Willow seedlings were first noted in 2006 but birch seedlings in 2010. In 2015, seedling density in revegetated plots with planted clusters was over 20 times greater than that of revegetated plots without clusters, indicating a strong seed limitation. No seedlings were found in plots that had not been revegetated, showing very strong microsite limitation. However, revegetation increased the cover of biological soil crust and other microsites favorable for seedling establishment. The results demonstrate that both seed and safe site limit the colonization of birch and willows, key species in woodland restoration, and highlight the importance of identifying barriers to spontaneous succession before selecting restoration strategies.

Seasonal evolution of soil organic matter, glomalin and enzymes and potential for C storage after land abandonment and renaturalization processes in soils of NE Spain

Rates of recovery of soil organic matter (SOM) in abandoned fields of Mediterranean Spain are affected by spontaneous succession in the vegetation, the occurrence of periodic wildfires and lack of forest management. Soil organic matter has a relevant role together with the renaturalization process of shallow soil under vines (V) and olive groves (OL), cork oak (S) and pine (PI) trees, pasture (PR), Cistus (MC) and Erica (MB) scrub in abandoned areas of NE Spain that are sensitive to fire. Physical, chemical, biological and biochemical properties of the soil determined season by season warned against its fragility. Pyrolysis-GC products showed in general moderate to strong positive and negative correlation with soil organic carbon (OC), easily extractable glomalin (EE-GRSP) and total glomalin (GRSP), β-glucosidase and protease, which strengthens the hypothesis that both less and more recalcitrant SOM fractions might be inferred and so there is a scale of potential carbon storage in the environments studied.Recently abandoned V and OL soil had small OC contents (mean 2.51±0.25 and 15.26±1.39gkg−1) and GRSP (mean 1.04±0.22 and 2.84±0.53gkg−1) and large contents of aromatic compounds. By contrast, PR and MB soil had large OC (mean 36.24±0.75 and 37.66±2.38gkg−1) and GRSP (mean 4.85±0.87 and 3.88±0.76gkg−1) content and smaller contents of aromatic compounds. This suggested a renewal of active OC in older soil. In fact, EE-GRSP and GRSP of more organic soil were positively correlated with the mineralization indices N/O (Furfural/Pyrrole) and O/Y (Pyrrole/Phenol) from active organic compounds (P<0.05 and P<0.01 respectively), and negatively correlated (P<0.05) with the humification index B/E3 (Benzene/Toluene) from recalcitrant organic compounds. Principal component analysis (PCA) identified those environments where soil renaturalization is better. Our findings might indicate the potential for carbon storage in different abandoned shallow soil environments under renaturalization in Mediterranean climate conditions.

Multivariate analysis for assessment of the tree populations based on dendrometric data with an example of similarity among Norway spruce subpopulations

The new method for evaluation of tree populations presented here is based on a correlation analysis within a set of dendrometric variables. The correlation analysis is carried out for each population separately. The method evaluates differences between resulting correlation matrices. These distances can be used by hierarchical cluster analysis (unweighted pair-group average) or by ordination analysis (non-metric multidimensional scaling – NMS). Test data were obtained in 10 research plots in the area of Medvědí Mt., Šumava National Park. Plots are located in Norway spruce [Picea abies (Linnaeus) H. Karsten] climax forests. The results enable ecological interpretation of both classification and NMS. The populations (subpopulations) differ in their origin (spontaneous succession or partial planting) and environmental conditions (extreme environment near the mountain summit versus water-logged soils). These differences were reflected in results of the classification and ordination of the spruce (sub)populations.

Succession in soil seed banks and its implications for restoration of calcareous sand grasslands

Spontaneous succession is increasingly involved in grassland restoration, because it offers a cost‐effective solution compared to technical reclamation methods. This topic is especially important nowadays, as large areas of marginal croplands are being abandoned on poor soils of Central and Eastern Europe, which offers a possibility for the spontaneous recovery of typical target grasslands. Studying the vegetation composition, aboveground biomass, and seed bank in old fields of different age and target calcareous sand grasslands using the chronosequence method, we aimed to answer the following questions: (1) Which species contribute to the seed banks of old fields and reference grasslands? (2) Does the direction of vegetation and seed bank succession trend toward the reference grasslands? (3) How are the vegetation changes in spontaneous succession reflected by the soil seed banks of old fields? In reference grasslands on the dune tops only sporadic seed banks were detected, while several hygrophytes had dense seed banks in reference grasslands in dune slacks. Similarity between the species composition of vegetation and seed banks was low. The development of vegetation and seed banks in old fields progressed toward that of target grasslands and the proportion of weedy species (e.g. indigenous weeds and invasive species) also decreased with time. The cryptogam biomass correlated significantly negatively, while the soil phosphorus significantly positively with the weedy species seed bank density. Our results indicated that the role of persistent seed banks in the regeneration of calcareous sand grasslands from old fields is rather limited and promising vegetation changes are mostly driven by spatial dispersal.

Rough wave-like heaped overburden promotes establishment of woody vegetation while leveling promotes grasses during unassisted post mining site development

Geodiversity plays an important role in species establishment during spontaneous succession. At post-mining sites in the Czech Republic in 2003, we established plots in which the surface of the heaped overburden was either kept wave-like or leveled. Based on surveys conducted from 2006 to 2015, leveled plots were increasingly dominated by grasses and herbs (and especially by the grass Calamagrostis epigejos) while the wave-like plots were increasingly dominated by the trees Salix caprea and Betula pendula.In 2015, a detailed survey was conducted of the dominant species. Both S. caprea and B. pendula occurred more often in wave-like plots than in leveled plots; this was particularly true for trees taller than 1 m, which were absent in leveled plots. In wave-like plots, leaf and root biomasses of both woody species were higher on the wave slopes than on the wave depressions. Nitrogen content was higher but content stress indicating proline in leaves of S. caprea was lower in wave-like plots than in leveled plots. In wave-like plots, both woody species occurred mainly on wave slopes but C. epigejos occurred mainly in the depressions. We speculate that trees were more abundant in wave-like plots than in leveled plots because the waves trapped tree seeds and snow and because the soil porosity was greater in wave-like than in leveled plots. Grasses may have preferred the leveled plots because soil porosity was lower and clay content was higher in leveled than in wave-like plots.

Spatial-temporal changes in trees outside forests: Case study from the Czech Republic 1953–2014

Trees outside forests act as ecologically valuable elements in the rural landscapes of Europe. This study proposes a new classification system for trees outside forest elements based on the shape and size of the patches and their location in fields. Using this system, the study evaluates the spatial-temporal dynamics of different subcategories of trees outside forests in context with land cover changes of the Czech Republic. The analysis is based on the re-evaluation of change trajectories of individual landscape elements. Historical black and white aerial photographs from 1953 and colour orthophoto maps from 2014 were used as data sources. Although the results show an increased area of trees outside forests, lost and recent elements exceed persistent elements in all subcategories. Regardless of subcategory, most of the lost elements were replaced by forest and the majority of recent elements were created at the expanse of arable land or grasslands. Most of the patches of persistent elements got larger due to spontaneous succession during the study period. Riparian vegetation was found to be the most stable category of trees outside forest. Reasons underlaying the documented changes are discussed based on the existing literature. In general, the dynamics of trees outside forests are linked to changes in the fine-grained microstructure of historical landscapes. The applied method enables us to analyse spatio-temporal changes on the level of individual elements, which allows for monitoring of changes in landscape processes.

Let native species take their course: Ambrosia artemisiifolia replacement during natural or “artificial” succession

Ambrosia artemisiifolia is able to dominate the early stages of vegetation succession in open/disturbed habitats, spreading out into available empty niches, after which it can be progressively replaced by perennial plants. In this study, we considered the time-span in which the species is suppressed during active (restoration actions) and passive (spontaneous) vegetation recovery. In particular, we envisaged that A. artemisiifolia growth and fitness may be strongly reduced and that the species may rapidly be suppressed within a short time during succession as a consequence of the increase of vegetation cover, both natural or artificially induced, in a disturbed area of northern Italy. Three different treatments were applied within an abandoned quarry area commonly invaded by A. artemisiifolia: (i) spontaneous succession i.e. (control), (ii) hayseed and (iii) a commercial seed mixture. We determined the effect of mixtures of grassland species, established from native hayseed or from a commercial seed mixture, on A. artemisiifolia growth and fitness traits over time in comparison to a non-seeded area left to spontaneous succession. The results demonstrated that, after the first growing season, compared with spontaneous succession, both commercial seed and hayseed resulted in a strong reduction of A. artemisiifolia abundance and growth rate, in terms of both vegetative and reproductive traits. After the second growing season, A. artemisiifolia was completely suppressed in the commercial seed treatment, and after the third growing season it was also suppressed in the spontaneous succession and hayseed treatments. This study indicated that both active and passive vegetation recovery (by niche filling and competitive exclusion) could be used as methods individually or in combination with other methods, such as mowing and biological control, to suppress A. artemisiifolia from anthropogenic habitats.

Biodiversity and Ecosystem Functional Enhancement by Forest Restoration: A Meta‐analysis in China

AbstractLarge‐scale forest loss and degradation have dire consequences for biodiversity maintenance and provision of vital ecosystem services. Despite recent increasing efforts for forest restoration and sustainable management, there have been no comparative studies of biological taxonomy and multiple ecosystem functions to assess the effectiveness of forest restoration programmes, and how they vary through space and time. Here, we provided a quantitative assessment of the recovery of biodiversity and ecosystem functions by forest restoration in China using a meta‐analysis of 172 studies. We found that biodiversity and ecosystem functions were substantially increased in restored forests comparing with the degraded states. However, these restoration effects varied considerably by degradation origin, restoration approach, restoration age, ecological domains, taxonomic group and ecosystem function that is measured. Results also revealed that forest restoration from degraded states could not lead to full recovery of biodiversity and ecosystem functions, highlighting the irreplaceability of primary forests. We advocate allowing for natural or passive recovery, especially where biophysical conditions are favourable for spontaneous succession, or too harsh for human‐aided restoration, and choosing a combination of passive and active restoration measures based on adaptive management strategies. Our meta‐analysis provided fundamental insights into bridging the gap between small‐scale experiments and broad‐scale management needs towards highly effective and sustainable forest ecosystem restoration. Copyright © 2017 John Wiley &amp; Sons, Ltd.

Can Soil Properties Determine Vegetation of Spontaneously Recovered Postmined Areas? Case Study of Limestone Quarry Mokrá

The role of soil properties for vegetation development during early spontaneous succession was studied in a limestone quarry Mokrá (south Moravia, Czech Republic). In particular, we would like to detect the soil environment features supporting the swards formation of expansive reed grass (Calamagrostis epigejos), which is able to arrest a succession process. Research was conducted along postmined quarry benches, where natural recovery took place. We examined water–air regime, soil organic carbon (SOC) content, total nitrogen content (Ntot), content of available calcium (Ca), magnesium (Mg), potassium (K), phosphorus (P), soil reaction (pH), and soil texture of soil samples collected separately from assemblages with abundant reed grass and without them, usually with the occurrence of tall oat grass (Arrhenatherum elatius). A multivariate statistical approach revealed the fact that soil texture, SOC, Ntot, and water–air regime were statistically significant for the vegetation types. Reed grass prefers fine grained soils with higher amount of clay and silt particles, whereas assemblages without abundant presence of this species settled coarse grained soils with higher sand or skeleton content. High SOC and Ntot values were also associated with sites covered with reed grass. Therefore, using these variables as a measure of recovery success in early succession might be a problem.

Relations between Biotic and Abiotic Diversity in Abandoned Basalt Quarry and Its Relevance for Ecological Restoration (Radobýl Hill, Northern Czechia)

The ecological value of abandoned quarries has gained increasing scientific attention in the last few decades, resulting in a paradigm shift in restoration programs regarding the use of natural processes. The linkages between biotic and abiotic diversity, such as landform and microclimatic diversity have been analyzed only slightly, however. In this paper, we use an interdisciplinary approach that includes vegetation mapping, geomorphological mapping, microclimatic measurements and modeling to reveal the specific two‑way linkages between abiotoc and biotic diversity. The present case study shows that in only 60 years landform diversity allowed the development of nine distinct biotopes with 134 identified species. At the same time, the vegetation diversity at these human‑induced biotopes is of high ecological value as it displays significant similarities with natural biotopes in the region (e.g., scree slope and rock cliff biotopes). Based on the results presented, the paper aims to contribute to current restoration programs involving processes of spontaneous succession and landforming.

Principal determinants of species and functional diversity of carabid beetle assemblages during succession at post-industrial sites.

Although ecological succession is one of the principal focuses of recent restoration ecology research, it is still unclear which factors drive this process and positively influence species richness and functional diversity. In this study we sought to elucidate how species traits and functional diversity change during forest succession, and to identify important factors that determine the species in the observed assemblages. We analyzed species richness and functional diversity of ground beetle assemblages in relation to succession on post-industrial localities after habitat deterioration caused by spoil deposition. We selected ground beetles as they are known to be sensitive to landscape changes (with a large range of responses), and their taxonomy and ecology are generally well-known. Ground beetles were sampled on the spoil heaps during the last 30 years when spontaneous succession occurred. To calculate functional diversity, we used traits related to habitat and trophic niche, i.e. food specialization, wing morphology, trophic level, and bio-indication value. Ground beetle species were found to be distributed non-randomly in the assemblages in the late phase of succession. Ordination analyses revealed that the ground beetle assemblage was significantly associated with the proportion of forested area. Environmental heterogeneity generated assemblages that contained over-dispersed species traits. Our findings indicated that environmental conditions at late successional stages supported less mobile carnivorous species. Overall, we conclude that the decline in species richness and functional diversity in the middle of the studied succession gradient indicated that the assemblages of open habitats had been replaced by species typical of forest ecosystems.

Effect of different restoration approaches on two species of newts (Amphibia: Caudata) in Central European lignite spoil heaps

Post-mining sites often offer secondary habitats for various amphibians endangered in common agricultural landscapes. On the other hand, there is a general lack of quantitative studies on the effects of the common restoration practices on colonisation of such artificial freshwater habitats by amphibians. Here, we focus on two newts decreasing in Central Europe, Lissotriton vulgaris and Triturus cristatus, in pools within lignite (brown coal) spoil heaps in the western Czech Republic. We compared their abundances in pools established by technical reclamation, spontaneous succession, and their combination. In spring 2016, we sampled 29 freshwater pools in five spoil heaps and 10 fishponds in the surrounding agricultural landscape by funnel trapping. We captured 52 L. vulgaris and 138 T. cristatus in all the studied habitats together. As only two L. vulgaris and no T. cristatus were caught in fishponds, the high potential of pools in post-mining landscapes was confirmed. Both newt species generally avoided the artificially established pools, but the spontaneously established pools were equally suitable for them in both technically reclaimed and spontaneously developed heaps. L. vulgaris preferred more transparent water, higher cover of cattails and the pool placed in the forest, but with fewer trees on the pool banks, whilst T. cristatus preferred narrower zone of littoral vegetation, more trees on the pool banks, smaller water bodies and absence of fish. Such habitat preferences fully corroborate with natural habitats. The technical reclamation still prevails in restoration of post-mining sites in many regions. We reveal it is an unsuitable practice for amphibians, if not combined with natural succession processes.

Development of Soil Characteristics and Plant Communities On Reclaimed and Unreclaimed Spoil Heaps After Coal Mining

The aim of this study was to compare soil characteristics, plant communities and the rate of selected ecosystem function performance on reclaimed and unreclaimed plots (left for spontaneous succession) of different age on spoil heaps. Twelve spoil heaps (three circle plots of radius 12.5 m) near the town Kladno in north-west direction from Prague, created after deep coal mining, were compared. Five mixed soil samples from organo-mineral horizons in each plot were analysed for total content of carbon, nitrogen and phosphorus. In addition, active soil pH (pHH2O) was determined. Plant diversity was determined by vegetation releves. The biodiversity value of the habitat according to the Habitat Valuation Method was assessed and the rate of evapotranspiration function by the Method of Valuation Functions and Services of Ecosystems in the Czech Republic were determined. The higher organo-mineral layers and higher amount of total nitrogen content were found on the older reclaimed and unreclaimed plots than in younger plots. The number of plant species and the total contents of carbon and nitrogen were significantly higher at the unreclaimed plots compared to reclaimed plots. The biodiversity values and evapotranspiration function rate were also higher on unreclaimed plots. From this perspective, it is possible to recommend using of spontaneous succession, together with routine reclamation methods to restore habitats after coal mining. Despite the relatively high age of vegetation in some of selected plots (90 years), both the reclaimed and unreclaimed plots have not reached the stage of potential vegetation near to natural climax. Slow development of vegetation was probably due to unsuitable substrate of spoil heaps and a lack of plant and tree species of natural forest habitats in this area. However, it is probable that vegetation communities on observed spoil heaps in both type of management (reclaimed and unreclaimed) will achieve the stage of natural climax and they will provide ecosystem functions more effectively in the future.

Combination of reclaimed and unreclaimed sites is the best practice for protection of aculeate Hymenoptera species on brown coal spoil heaps

The study focused on aculeate Hymenoptera recorded at 114 study plots on seven brown coal spoil heaps (reclaimed and under spontaneous succession) situated in the North Bohemian Brown Coal Basin, Czech Republic. In total, 2706 individuals of 212 species from 13 families were collected using Moericke traps. Of this number, 46 rare species (2 regionally extinct, 7 critically endangered, 14 endangered, and 23 vulnerable), 5 species protected by law, and 3 other rare species were recorded. Species typical of sand banks and open landscape were most numerous. The communities were dominated by Lasioglossum species, Diodontus minutus and Bembecinus tridens on unreclaimed sites, and Apis mellifera, Lasioglossum pauxillum, and Osmia rufohirta on reclaimed sites. Unreclaimed sites hosted twice as many rare species at four times greater abundances. Rare species occurred there more frequently than at reclaimed sites. Species known as regionally extinct, Evagetes littoralis and Nomada minuscula, were found only on unreclaimed sites. Redundancy analysis showed that especially threatened species are connected with sandy sites small in area and with sparse vegetation cover. The number of rare species slowly increased with age, but young sites, too, could be very rich. It is recommended to combine succession and reclamation approaches to create suitable nesting habitats, refuges, and food resources. It is essential to maintain a fine mosaic of habitats in various (above all young) successional stages.