The biological survey of the Tovacov lakes area found 554 plant species, 107 spider species, 27 dragonfly species, 111 butterfly species, 282 beetle species, 17 orthopteran species, and 7 amphibian species. Rare species were found particularly in humid and dry open habitats and coastal lake zones. Technically recultivated sites became species-homogeneous quickly while spontaneously succeeding sites remained species-rich during development. To maintain biological diversity, appropriate management was suggested for the most valuable areas.
CSR_Module5_Green Earth Initiative, Tree Planting Day
Biodiversity Research of Tovacov Lakes
1. Research of the biodiversity of Tovacov lakes (Czech Republic)
Main researcher: Jan Ševčík
Research group: Vladislav Holec
Ondřej Machač
Jan Ševčík
Bohumil Trávníček
Filip Trnka
March – September 2014
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Abstract
We performed biological surveys of different taxonomical groups of organisms in the area of Tovacov lakes. Many species were found: 554 plant species, 107 spider species, 27 dragonflies, 111 butterfly species, 282 beetle species, orthopterans 17 and 7 amphibian species. Especially humid and dry open habitats and coastal lake zones were inhabited by many rare species. These biotopes were found mainly at the places where mining residuals were deposited or at the places which were appropriately prepared for mining by removing the soil to the sandy gravel base (on conditions that the biotope was still in contact with water level and the biotope mosaic can be created at the slopes with low inclination and with different stages of ecological succession). Field study of biotope preferences of the individual species from different places created during mining was performed using phytosociological mapping and capture traps. Gained data were analyzed by using ordinate analyses (DCA, CCA). Results of these analyses were interpreted as follows: Technically recultivated sites are quickly getting species – homogenous. Sites created by ecological succession are species-richer during their development. Final ecological succession stage (forest) can be achieved in the same time during ecological succession as during technical recultivation.
According to all our research results most biologically valuable places were selected. Appropriate management was suggested for these places in order to achieve not lowering of their biological diversity. To even improve their biological diversity some principles and particular procedures were formulated. Also principles and procedures ensuring attractive environment for plant and animal species were formulated.
Introduction
High capacity mining of sandy gravels by floating excavators usually means very strong and distinct intervention to the landscape. There are many points of view on this activity. Biological point of view is one of the most important ones. Biodiversity is really important landscape-creative element because landscape character is very strongly connected also with life quality of people. The question consequently is if mining in certain area is able to support biodiversity of landscape and which interventions and technological processes are crucial. Other important question is if supported and raised biodiversity is possible to manage although mining is finished. Then we need to decide which type of recultivation is the best to support the goal of raised biodiversity. Biological parameters of specific mining locality need to be known first.
Objectives
Our study area is still changing due to continual mining. There is a possibility to create biological interesting biotopes in places where active mining and material manipulation take place. Already mined places can be gradually enhanced for occurrence of rare species and for recreation. This high potential of such localities was and is not utilized yet. Provision of information to improve current situation is our main objective.
This study is focused on biodiversity research and support in the area influenced by mining. We used following methods: (1) inventory surveys of chosen taxonomical groups of organisms and (2) field study of biotope preferences of individual species. On the basis of obtained data it will be possible to identify (3) rare species occurring in our study area and (4) rare biotopes. For that biotopes appropriate management ensuring not lowering of their biological values will be suggested. (5) Adjustments of some technological processes will be proposed according to our findings.
Background information
The region between municipalities Tovačov and Troubky lies in the river Morava basin. This area is called “Haná” and it is located in the Middle Moravia in the east part of the Czech Republic. The region is typical by quite warm climate, optimal precipitation amounts and high-quality soils. Natural and semi-natural habitats rich in biological diversity of plant and animal species existed here in the past till now. Consequently local high- quality soils were used for intensive agriculture and the amount of natural habitats decreased a lot. Remains of riparian forests can be still found here but subsequent meadows and wetlands were strongly reduced during last decades. All these changes caused decline and reduction of many populations belonging to different groups of organisms.
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In the area of Tovačov lakes sandy gravel have been mined largely since the fifties of the 20th century. The system of four lakes was created varying in age and depth. The majority of lakes have already firmed banks which were technologically recultivated in the past (by evening the terrain out and its afforestation or grassing over). However some places (especially majority area of the island among lakes I, III and IV) were left for ecological succession.
Generally, our study area is part of vast wetland region (obr. 1). Tovačov region (357 ha) and Troubky region (149 ha) comprise mostly of the area of lakes (70 %). Local relief is quite plane ranging between 191 – 210 metres above sea level.
This region is biologically valuable which is also supported with categorization of the lakes I, III and IV into Special Protection Area (SPA Morava – Chropyňský luh – EVL CZ 0714085). Although the only subject of official protection according to Natura 2000 is the European beaver (Castor fiber). The locality is also rich in birds but the diversity of other organisms is not very well known yet.
Social importance of this locality should not be neglected. Lake III is favourite fishing and diving territory and is also used for recreation by local people. Lakes I and II are drinking water reservoirs.
Methods
Inventory surveys
Fieldwork took place from 26th of March to 23rd of September 2014 and consisted of 25 botanical visits and 33 zoological visits. Detailed inventory surveys of main taxonomical groups of bioindicating organisms were performed (vascular plants, beetles, spiders, amphibians, reptiles, daily butterflies, dragonflies). Other organism groups were not systematically mapped because of sufficient knowledge about it and because of other ongoing projects (for example birds). These organisms were just written down if they were spotted.
To exactly describe the environmental variability and to specify floristic and faunistic records our study area was divided into partial sites. These partial sites were created by combining different site ages, succession types, the way of site origins and different vegetation cover. Partial sites for particular taxonomical groups were consequently adjusted (Fig. 2, Fig. 3).
Programs Janitor (2.6.4.) [65] and QGis 2.4. [70] were used to process GPS data gained during the field work by GPS machine Garmin eTrex 30. Map sources are from Geoportal Cenia [64]. GPS coordinates are given in WGS 84 format.
All biotope mapping was done according to the Habitat Catalogue of the Czech Republic [1] and Manual evaluation of habitat [2]. Borders among specific biotopes at the actual orto-photo picture were defined straightly in the field. To identify biologically valuable places standard deviations of their approximate values were established [3]. Floristic inventory survey was done according to standard floristic methods placing emphasis on recommendations in Methodology inventory survey of specially protected areas [4]. Documentary plant material was collected, prepared and preserved by standard methods [5] and is located in herbarium of the Department of Botany of Palacky University in Olomouc (OL, [6]). Literary survey of available floristic databases was done [7, 8, 9, 10, 11].
Bryophytes were studied just briefly at the uncovered sites to compare it with natural bryophyte communities at the eroded river Morava banks nearby.
Animals were studied by using individual collecting, beating the vegetation, sweeping, sieving, light trapping, bait trapping and pitfall traps (plastic cap filled with saturated solution of salt and vinegar buried in the ground with its rim at surface level). All collected animals and animal material is deposited in the private collections of the researchers – F. Trnka (Coleoptera), O. Machač (Arachnida) and V. Holec (Lepidoptera and Odonata).
Dragonflies were studied by recording of exuvia, mature individuals (M for males, F for females), immature individuals (Imm for new-born individuals) and epigamic behavior (T for tandem, O for oviposition). If exuvia were found the population was considered to be indigenous. If immature individuals were found and if epigamic behavior was observed the population was considered to be likely indigenous [12].
Concerning butterflies daily ones were recorded in the first place (Papilionoidea group, Hesperioidea group and the family Zygaenidae). Also some big nocturnal butterflies were recorded (Cossoidea, Lasiocampoidea, Bombicoidea, Drepanoidea, Geometroidae and Noctuoidae group) at the locality “island”.
Amphibians were studied during night and day time visits by voice recordings, capturing to the nets and into the bait traps. Sites used as places for amphibian reproduction were systematically searched.
The categorization of threat (further just RL as Red list) were used: for vascular plants from the Checklist of vascular plants of the Czech Republic [13], for bryophytes from last version of the Bryophyte flora of the Czech
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Republic [14], for animals from the Red list of threatened species in the Czech Republic – Invertebrates [15] and Red list of threatened species in the Czech Republic – Vertebrates [16]. For vascular plants categorization by indigenous or invasive status was done [17]. All species protected officially by Czech law (§) were recorded [36].
Sources of the taxonomic references
Plant species nomenclature is given according to the Checklist of vascular plants of the Czech Republic [13], Charophytes (Characeae, Charophyta) of the Czech Republic [18] and Bryophyte flora of the Czech Republic [13].
Animal species nomenclature is given according to the actual version of the World spider catalog [19], Checklist of harvestmen of the Czech Republic [20], Molluscs of the Czech and Slovak Republics [21] and Checklist of Lepidoptera of the Czech and Slovak Republics [22]. Nomenclature for the orders Orthoptera, Dermaptera and Dictyoptera is given according to Kočárek et al. [23, 24]. Beetle species nomenclature is given according to Check-list of Czechoslovak Insects IV (Coleoptera) with updated taxonomical changes according to current literature [26, 27, 28, 29, 30, 31, 32, and 33]. Nomenclature for the order Odonata is given according to actual version of the World Odonata List [34].
Field studies
For the field studies the area of the island (Fig. 4) was chosen because of exclusion of different organism immigration from the neighborhood. The island was created by depositing of spoil. History of individual partial sites was reconstructed on the basis of information gained from the mining company and comparison of actual orto-photo pictures with historical ones from the years 2012, 2009, 2006, 2003, 1990 [63, 66-69].
Technical recultivation included terrain stratification, evening the terrain out or afforestation. Spontaneous succession included succession taking place in sites which were created by depositing the spoil. For both types of succession absence or presence of recent disturbances was recorded in comparison with orto-photo pictures from 2009 and 2012.
Study sites were categorized into 2 groups according to humidity. Category “wet” included sites which were influenced by stagnant or running water just for some part of the year. Category “dry” included sites with the absence of surface water. The site height above water level was set approximately to the height of the water level of the nearest lake.
Standard sites for phytosociological plots had proportions 7x7 m. In biotopes located in water and narrower than 7 m proportions of the site was adjusted to have approximate total area about 50 m2. To express quantity and abundance of plant species at the site 9-point Braun-Blanquet scale was used. Finally 36 phytosociological plots were analysed.
To study invertebrate diversity pitfall traps were used. These traps were collected once a month (4 times at all).
Vegetation structure was determined on all sites (levels E0 – bryophytes, E1 – herbs, E2 – shrubs, E3 – trees) together with percentage of the substrate not-covered by plant vegetation and percentage of the substrate not-covered with plant litter. Also type of the substrate was recorded (sand – fine substrate without clayish parts, in dry conditions falling into pieces, clayish sand – oligotrophic sandy substrate with clayish parts, clay – clay soil originating from the overburdens rich in nutrients), (Tab. 11).
Ordinate analyses were used to analyze our data using CANOCO 4.5 [35]. Regarding discovered gradient length (6 SD) unimodal DCA (Detrended Correspondence Analysis) analysis was used. For further analyses vegetation cover data were root extracted and weight of rare species was lowered. Canonical correspondence analysis (CCA) was performed to reveal the importance of specific factors of the environment to floristic composition of studied sites. It was also performed to reveal the group of factors that are the best to explain the species composition (forward analysis, Monte Carlo permutational test).
Results
Bryophytes (Bryophyta)
All of the found bryophytes (Tab. 1) belong to the species with short life cycle with big reproduction potential. Usually it reproduces by gems. Following species were frequently found: Bryum dichotomum, Barbula unguiculata, Funaria hygrometrica, Leptobryum pyriforme and Ceratodon purpureus. Bryum gemmiferum is one of the most interesting found moss species. It belongs to least concern species (LC-att). Majority of the found bryophyte species also grows at the banks of the Morava River. But other bryophyte species growing at the banks of the Morava River were not found in the study area.
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Vascular plants (Plantae)
In total 554 vascular plant species were found in our study site during the field survey (Tab. 2, Fig. 9, 10). Out of this total number 47 species belong to the Red list. Almost half of the species can be found in the central part of the study site (at the island). Disturbed anthropogenic biotopes were inhabited by following species: Kickxia elatine (C2 t), Dipsacus laciniatus (C3), Filago arvensis (C3), Vulpia myuros (C3) and Dysphania botrys (C3). Periodically not-covered substrates at the lake edges and pools are frequently populated by Cyperus fuscus (C3), Limosella aquatica (C4a) and rarely by Centaurium pulchellum (C3) and Carex bohemica (C4a). Water plants are very important group in our study site. We can found them especially in the lake III creating rich water vegetation consisted mainly of Potamogeton nodosus (C3) and rarely of Batrachium circinatum (C3) and Najas marina (C3). Rich population of Epilobium parviflorum (C3) was found in humid reeds. In our study site which is quite large only 30 plant species considered to be invasive were found (just 5 % out of the total number of all our found species). Then 57 plant species can be regarded as neophytes. All not indigenous plant species (including naturalized) cover 25 % of the whole study site. According to the literature survey other 132 plant species are noted from Tovačov lakes (25 other plant species belonging to the Red list, 8 invasive species, 24 neophytes).
Spiders (Araneae)
In total 107 spider species belonging to 15 families were found in our study area (Tab. 4, Fig. 12). Sheet weavers from the Linyphiidae family (16 species) and wolf spiders from the Lycosidae family belonged to the most frequent species. Majority of recorded spiders is considered to be common species living mainly in forest and open habitats. We found 4 species from the Red list – Ozyptila brevipes and Myrmarachne formicaria as vulnerable species (VU) and Tmarus stellio and Arctosa cinerea as endangered species (EN). The findings of following spider species can be evaluated as regionally important: Synema globosum, Larinioides patagiatus, Donacochara speciosa or Heliophanus auratus.
Harvestmen (Opiliones)
In total 7 harvestman species belonging to 3 different families were found in our study area (Tab. 4). They belonged to the common forest and open habitat species. Phalangium opilio was the most frequent species at the locality.
Dragonflies (Odonata)
In total 27 Odonata species (11 of the Zygoptera suborder and 16 of the Anisoptera suborder) were recorded during our survey. It is more than one third of the dragonfly species occurring in the Czech Republic. We found 8 species from the Red list – Erythromma viridulum, Ischnura pumilio, Sympecma fusca and Sympetrum striolatum as nearly threatened species (NT), Anax parthenope and Aeshna affinis as vulnerable species (VU) and Orthetrum brunneum and Ophiogomphus cecilia as endangered species (EN).
Indigenous population was confirmed for 6 species and likely indigenous one for 11 species (Tab. 5). The banks of the oldest lake with rich water vegetation was the most favorite biotope for in total 18 species of the dragonflies. Aeshna mixta and Erythromma viridulumwere the most typical species there. Younger lakes with minimum of water vegetation were inhabited by dragonflies less. Shallow warm lagoons were inhabited by Orthetrum albystilum and Sympetrum striolatum. Small water sites (puddles and small pools with minimum water vegetation at strongly anthropogenic sites) were inhabited by Ischnura pumilio, Sympetrum striolatum and threatened Orthetrum brunneum. Nevertheless indigenous population of this species was not recorded.
Orthopterans (Orthoptera), Earwigs (Dermaptera) and Mantids (Dictyoptera)
In total 17 species of the Orthoptera order and 3 species of the Dermaptera order were found in our study area (Tab. 8, Fig. 12). Majority of the species found belong to the common and frequently occurring species. We found two rare species – pacvrček písečný (Xya variegata) as vulnerable and škvor velký (Labirura riparia) as endangered species. Both species are connected with wet sandy banks of rivers and sandpits. Also the only mantis of the Czech Republic – Mantis religiosa considered to be vulnerable was found.
Butterflies (Lepidoptera)
In total 112 butterfly species of the 16 families were recorded (Tab. 6). Common and frequent species from the forest and open habitats and from the humid forest edges or prevailed. We found 3 species from the Red list [15] – Cupido decoloratus as nearly threatened species (NT) and Mormo maura and Iphiclides podalirius as vulnerable species (VU). The findings of following butterfly species can be evaluated as regionally important – Archanara geminipuncta and Macrochilo cribrumalis which are connected with humid reeds. Also one of the Czech biggest butterflies was found – Saturnia cf. pavoniella.
Daily butterfly community of Tovačov sandpit can be labeled as poor. Majority of species was recorded at the mowed coastal sites in the part 2b. Soumračník máčkový (Erynnis tages) is the most common species of the non-forested anthropogenic sites of the Tovačov sandpit. More numerous Nymphalidae populations were recorded in the summer at the part 3a during sucking of ripened Prunus cerasifera.
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Beetles (Coleoptera)
In the Tovačov sandpit 282 beetle species of 43 families (Tab. 7, Fig. 11) were found during our survey. Superfamily Curculinoidea (Anthribidae, Apionidae, Curculionidae, Nanophyidae and Rhynchitidae) with 81 species and ground beetles (Carabidae) with 70 species were the most numerous groups. Most of the species found there are common frequent species but the site is so unique that it allows to survive to some rare threatened species of the Czech Republic. Majority of the rare species is typical for open habitats with minimum vegetation (see Discussion). In total 7 species in the category endangered were found according to the Czech law. Also 21 species from the Red list were recorded. Harmonia axyridis was the only invasive species found.
Amphibians (Amphibia)
In total 7 amphibian species were recorded (Tab. 9). Six of them are listed in the Red list as nearly threatened (NT). All of these species are protected by law in the Czech Republic. Successfully reproducing, strong and interbreeding populations of the „zelených skokanů” Pelophylax ridibundus and Pelophylax esculentus complex are present in all big water sites at the locality despite of high levels of kept fish. Green toad (Bufotes viridis) is the typical inhabitant of the Tovačov sandpit using water sites just in the time of reproduction. Tadpoles and eggs were found in all small sunny water sites with minimum of vegetation and without fish predators at the open anthropogenic sites.
Reptiles (Reptilia)
Just 2 reptile species were recorded (Tab. 9). Common lizard (Lacerta agilis) is the species present in Red list as nearly threatened (NT). It is also protected by Czech law as the endangered species. Užovka obojková (Natrix natrix) is the second reptile species found and it is also protected by Czech law as the endangered species. Both species populations are strong and frequent at the study site and reproduce here successfully and regularly. They inhabited sunny sand walls at the lake banks where they find food and shelters. They also inhabited technically recultivated banks. They are not negatively influenced by recreation at the study site.
Biotopes
We found 21 biotopes from the Habitat Catalogue of the Czech Republic (Fig. 5, 6, 7; Tab. 3) in our study area. Natural biotopes include 8 biotopes and cover 28 % of our study area. The rest of the percents include biotopes strongly affected or created by human (category X). Biotopes important for nature conservation (V1F, M1.1, M1.3, M2.1, L1, X6, X7A a X12A) cover the area of 70 ha (13 % of the whole study area). These biotopes (anthropogenic influenced) are located mainly at the sites prepared for mining or at the sites created during working with mined material. All naturally rich and valuable places are connected to coastal zones of the lakes and humid sites (Fig. 8).
Field studies
The main variability gradient was connected with the humidity conditions of the site (dry versus humid). Dry type is correlated with nutrient rich type of substrate. This type of substrate is usually delivered to the site during technical recultivation. These two factors are changing succession very much. The second gradient is correlated with succession age and disturbances (Fig. 13). Technical recultivation has very deep impact for following succession. Differences in the species composition variability between younger and older sites is lower at the technically recultivated sites than at the ecological succession created ones. Technically recultivated sites are going almost just in one direction and these sites become homogenous quite quickly. The sites created by ecological succession have bigger heterogeneity of microhabitats and species exchange is higher. Final succession stage (forest) can be achieved by ecological succession almost in the same time as by the technical recultivation. Sites that are younger in succession have bigger diversity of the species composition (Fig. 14). Not disturbed sites gets different from the disturb ones during time significantly (Fig. 15). More disturbances can stop the succession (especially in coastal zone vegetation).
Most variability of species composition in studied set (rough influence) can be explained by influence of the nutrient rich substrate (Tab. 12, 13). Other important factors are (in descending order, rough influence): succession age, humidity conditions and the occurrence of disturbance.
According to partial DCA analysis of the species composition with removing the influence of the humidity conditions main variability direction can be interpreted as the gradient of disturbance and time (from disturbed mainly young sites to non-disturbed mainly older sites). Younger sites are typical by species of not-covered disturbed substrates, for example Bolboschoenus, Typha latifolia, Gnaphalium uliginosum, Alisma lanceolata, Cyperus fuscus or Eleocharis acicularis. Technically (by afforestation) recultivated sites are typical by species of mid- and eutrophic habitats, for example Urtica dioica, Sambucus nigra, Galium aparine and Glechoma hederacea (Fig. 16).
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During the survey community composition of spiders (Fig. 17) and bugs (Fig. 18) was also assessed by analyzing samples of soil traps by DCA. In the case of spiders first two DCA ordination axes explain 65 % of the variability in species data. Main variability direction of the species composition of spiders along the first ordination axis is associated with a humidity gradient, which is combined with a gradient of disturbance and succession age. In the left side of the ordination diagram we can find communities of spiders occuring in older sites, mostly forest or shrub vegetation on relatively drier sites, with high abundances of litter on the soil surface. For these habitats Centromerus sylvaticus, Diplostyla concolor or Trochosa terricola are typical species. In the right side of the ordination diagram, there are communities of spiders typical rather for wetter habitats. The second most significant gradient (along the second axis) is connected with the type of the substrate and the ratio of the uncovered surface. At the bottom of the ordination diagram species Arctosa cinerea, Pardosa agrestis, Robertus arundineti and Xerolycosa miniata are found, which indicate the uncovered sites with little vegetation, thus early successional stages. Oedothorax retusus and Arctosa cinerea also prefer areas with higher humidity, therefore the banks of the water. At the top of the ordination diagram Pirata latitans, Pardosa amentata and Trochosa spinipalpis are found – typical for more developed herbaceous vegetation on sand with soils.
In the case of beetles first two DCA ordination axes explain the smaller proportion of the total variability in the species data set (45 %). Like for plants and spiders the main gradient is associated with habitat moisture (dry vs. wet), which correlates with a gradient of disturbance. The left side of the ordination diagram indicates the species with connection to older successional stages with developed vegetation (often in technically recultivated sites). Technically recultivated sites are mainly inhabited by eurytopic rather common species, often linked to the forest environment, such as Pterostichus oblongopunctatus, Pterostichus melanarius, Abax parallelepipedus and Phosphuga atrata. The right side of the ordination diagram indicates the species typical for disturbed sites. Similarly to the spiders the second most important gradient (along the second axis) is connected with the nature of the substrate and the ratio of the uncovered surface. Disturbed moister habitats created by spontaneous ecological succession are inhabited by species typical for river sediments such as Chlaenius nitidulus, Cylindera arenaria or Omophron limbatum. Sandy habitats with little vegetation are inhabited by species such as Barypeithes mollicomus, Cicindela hybrida, Cicindela campestris or Cylindera germanica.
Discussion
Inventory surveys were conducted only for one season and so the the number of taxa is not certainly finite. Plants were compared with the literature [7, 8, 9, 10, 11] found 132 species more. But it is probably caused by setting the solutions of our study site. Most of our study site did not agree with the outlined boundaries from the literature. Many species are found only in the vicinity of Tovačov lakes (eg. Arum or Allium scorodoprasum) and some species are only grown in nearby gardens. Apparently cultivated species were not recorded in this survey. Some of determination difficult species may also be a confusion (eg. Festuca brevipila vs. F. psammophila) and confusion may occur even in the field thanks to lax approach to determining the well recognizable species (Ailanthus altissima vs. Juglans nigra). Number of species found this year in comparison with botanical surveys in size similar area (protected reserves) [37, 38, 39, 40] shows that it is a botanically very rich territory despite the fact that it is largely composed of water surface without vegetation . Regarding spiders and beetles the number of species found is also relatively high.
Most of the Tovacov lakes have no larger littoral areas. Despite this fact several rare aquatic macrophyte species were found. For this group the most important littoral zone is located at the lake III. Its rich coastal population of Najas marina and Potamogeton nodosus probably developed as a result of a combination of water purity and lower stocking of large herbivorous fish in the past (eg. carp and grass carp). Although there is not ideal lake littoral zone, the purity of the water allows the development of rich macrophyte vegetation communities. In some places there are continuous vegetation units at a depth of over 2 meters. Thanks to the considerable gains, these plants are able to compensate for grazing, and therefore the current fish stock is likely to not have a negative impact. Smaller populations of macrophytes are also located in other lakes. The lake IV development of these communities is hindered by high turbidity of water and artificial waves caused by sand mining. The lake I and II development of any aquatic plants is likely prevented by grazing of large herbivorous fish. The same situation is at the site 7f. Riding a jet ski or speedboats might be another threat. More frequent waves disrupt the growth of plants with floating leaves and shallower littoral zones and it is certainly one of the limiting factors in the development of wetland communities [41].
Littoral zones of the lake III (in parts with rich submerged aquatic vegetation) host also the most varied dragonfly communities. In comparison with the number of recorded species of dragonflies in anthropogenic
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water sites created by mining of the hard coal in Karvinsko region [42] can be our study site at the Tovacov lake III identify as the poor one. This can be explained by increased fish stocking, which negatively affects the development of aquatic vegetation and thus the dragonfly communities in all lakes in the area of our interest. Still lake III hosts a strong population of Erythromma viridulum. This species is bound to the water surface with developed floating water vegetation [42, 43]. Findings of following species can be considered as regionally important: Anax parthenope, Aeshna affinis and Crocothemis erythrea. However, the indigenous population of these species could not be proved.
Surprisingly, very small number of species of water beetles was found (Dytiscidae, Hydrophilidae and Haliplidae). It seems deep littoral zones are not suitable for aquatic beetles. Most species inhabit mainly sunny pools and small lakes at the site 4b. For water bugs smaller pools around large lakes should be created (similar as for amphibians) or to modify littoral zones to be gradual and shallow.
Humid reeds at the lake edges are biologically valuable. In the surrounding ponds this biotope slowly disappears due to intensive fish farming, or it was not developed at all there. Moreover, the presence of littoral vegetation positively influences the character of the aquatic ecosystem and water quality [44, 45]. There are not so many rare species of plants occuring in the reeds at the Tovačov lakes (for example just Epilobium parviflorum – C3), but the potential of the reeds is much higher. There was also detected quite a diverse community of wetland species of spiders with several prominent representatives such as Myrmarachne formicaria, Donacochara speciosa or Heliophanus auratus. In the reeds biotope specialists from Lepidoptera group occur, too, for example Archanara geminipuncta or Macrochilo cribrumalis. These are hygrophilous species of the family Noctuidae with a narrow food-bound to the humid reeds [46].
Willow shrubs often develop at the edges of lakes. They serve as a food for beavers. Beaver damaged trees are specific habitat for rare longhorn beetles as Aromia moschata and Lamia textor. Both species are now disappearing from the landscape like the old willows and willows grown on the head [47]. At appropriate places rich wet alder forests are connected to the humid reeds. Riparian water vegetation is also inhabited by Mormo maura, which in the open landscape is threatened especially by insensitive technical modification of water flows and excessive felling of riparian vegetation.
Most rare and endangered plant species were found at the sites not-covered with vegetation or at the wet sites (Fig. 20). Relatively large fluctuations of water level during the year can raise species diversity during the restoration from the seeds [48, 49]. In the Tovačov lakes these fluctuations enable the development of communities of species connected with uncovered bottoms. These biotopes are developed mainly in a gradual descent shores caused by storing historical mining residuals or at the edges of shallow pools and not-shaded sites on the exposed surfaces ready for mining. Artificial biotopes of uncovered bottoms are not-covered wet sites created by the movement of heavy machinery or by disruption of humid reeds by a movement of holidaymakers and fishermen.
One of the most valuable sites in the area of our study were created by actual mining, respectively by creating of mining residuals and storing them at the edges of lakes. The recently abandoned mining residual site (7f) is now inhabited by many interesting species of spiders. Most important one is relatively large population of Arctosa cinerea. At the shrubby edges of this site relatively rare Ozyptila brevipes was found in reed debris. It can be assumed that in appropriate places (such as vertical walls in the banks of the nearby lakes) very rare Sitticus dzieduszyckii and Caviphantes saxetorum could occur. These species typically occur on sandy gravel sediments of the Morava River in the nearby Zástudánčí NPR [50]. Critically endangered click beetles Negastrius sabulicola and Zorochros meridionalis inhabit sandy gravel sediments of rivers and use the young minig residual sites without vegetation as a secondary habitat. These two species are typical for sand and gravel sediments of rivers with little vegetation [32]. Another click beetle (Z. meridionalis) is known for using quarries, sand pits and railway embankments as secondary habitat [51, 52]. The genus Bembidion belongs to the other species typical for wet sand and gravel river sediments, including rare Xya variegata, Labidura riparia, endangered species Bembidion testaceum and vulnerable species Bembidion modestum. These two ground beetles are typical for not-shadowed river banks without vegetation, just like rare Nebria livida, Perileptus areolatus, Dyschirius nitidus or Cylindera arenaria [5]. Related Cylindera germanica prefers drier sites because it is typical species of grasslands and field margins [53]. Drier sites with no vegetation are used by Meloe proscarabaeus whose larvae parasitize in the nests of Hymenoptera. Sites with little amount of the vegetation on wet sands with decaying vegetation [54] are inhabited by Anthicus sellatus. In contrast, vegetated banks are prefered by vulnerable species Pterostichus gracilis, Tetartopeus rufonitidus and endangered species Phaedon laevigatus (that lives at Galeopsis spp.). The occurence of most of these rare beetle species is known also from the nearby Zástudánčí NPR [55, 56]. Unregulated river stream with sandy gravel deposits is protected there. It seems many rare species can use mining residual sites without vegetation
9. 8
as a secondary habitat (Fig. 19). Also bryophytes found at the sites not-covered with vegetation grow in Zástudánčí at the banks of the Morava River [57, 58].
The above-mentioned communities are very rare in the central Moravia and they should be the main objective of nature protection of this area. Littoral sites as well as other field depressions are often a place where the soil created during mining preparations, spoil or mining residuals are stored. Thus a large number of rare species can disappear from the site very quickly. In the past the lake with the occurrence of Myriophyllum verticillatum and Potamogeton trichoides was filled – both C3 species. This year the site with the occurence of Carex bohemica – C4a species – was destroyed. Any technical recultivation is fatal for most of the rare species living in these exposed habitats – especially the portion of topsoil and subsoil or subsequent planting of trees or grass. Gradual creation of shallower water in places with steep banks is definitely much better use of the topsoil or subsoil. The disappearance of these rare species is also happening at the final stages of ecological succession, but some other rare species may discover – for example at the sunny edge of a young forest formed by natural seeding very rare Tmarus stellio was catched.
Not all technically not recultivated site with mining residuals is able to maintain its biodiversity. The most valuable ones are those where a slow gradient from the shallows in the lake to xerotherm habitats was created. In areas that have lost contact with the littoral zone of lakes, the species composition is much poorer. The oldest site sedimentation took place right on the edge of the lake VI. After completion of storage in the 80s a continuous gradient of environmental conditions was created with different subsequent communities of uncovered bottoms, reeds, humid willow shrubs and forests along with dry not-covered substrates. Other storage sites for mining residuals are bounded by high banks and filled to their surface. During the period of their service they can serve to many rare species (eg. Equisetum ramosissimum known from the site 7e [10]). After completion of storing mining residuals however, the area is quickly drying and virtually all species present disappear, with the exception of those with high ecological valence (eg. reed and cane). The only ones rare species present at such locations are beetles that are tied to the sunny bare substrates. It would be much better to stop storing mining residuals in a time when it creates sandy islands and shallow water sites. The current, up to 3 m tall banks could thus be very low and after stopping storing mining residuals they could serve as littoral zone.
Neither the sites prepared for mining may not always offer suitable conditions for the creation of ephemeral communities. Wavy terrain with many different heights and substrates is not always created. Such environment is dependent not only on the properties of the mining site, but also on a method of removing the soil by excavators. It can be seen especially at the borders of the various stages of the mining. During some periods wavy terrain with many different heights and substrates is created during mining preparations. In other times monotonously stripped substrate is created at the same bedrock. Although these are sites prepared for early excavation, specific communities are developed there, which, thanks to the continuity of habitat (sites prepared for mining are connected with each other all the time mining follow) provide permanent existence of ephemeral plants and rare animals (eg. the successful reproduction of green toads is possible there at one of two locations in the area of interest).
Small water sites created by mining equipment movements or by mining of material on the exposed sites of the studied area were settled by Ischnura pumilio or Orthetrum brunneum. They are considered to be rare, pioneer species of dragonflies, which are often the first colonizers of newly created water sites. They disappear later in connection with the ongoing ecological succession [42]. Small water sites are also important for the lives of amphibians in anthropogenic habitats of our study area. They are used for egg laying and larval development of green toads (Bufotes viridis) and green tree frogs (Hyla arborea). These species prefer the sunny shallows of the new, small water sites, often in sand pits [59].
These water sites are characterized by little vegetation, the absence of fish predators, warm water and susceptibility to extinction by vegetation overgrowing and drying. Their presence clearly increases species richness of the area and it is necessary for the existence of a series of species protected by law.
Scarce ruderal vegetation is the last interesting habitat. It may be a secondary habitat for rare weeds such as Kickxia elatine found at the disturbed sites. Furthermore, vulnerable weevil species Cyphocleonus dealbatus live at these biotopes, although it has been slowly disappearing from the Czech countryside for a long time [60]. Thistles from these biotopes are necessary for the development of Larinus sturnus. Endangered Cassida rufovirens live at the Matricaria spp. growing in these biotopes. In sites with scarce ruderal vegetation we can also observe the occurence of Cupido decoloratus, which is currently spreading and colonizing anthropogenic habitats of ruderal character [61].
These sites are soon overgrown with cane or reed and the other competitively strong species. It is therefore necessary to mechanically disrupt them regularly, as well as all other habitats exposed to the bare substrate- bound species.
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Conclusions and recommendations
Coastal lake zones and disturbed open habitats hosted most biologically valuable biotopes. Coastal lake zones are recovered periodically by fluctuation of the unstable water level. Disturbed open habitats are strongly transitory and under the influence of ecological succession. These habitats are quickly vanishing that is why it is necessary to recover them by periodical management. These open habitats were created during the mining so mining is very important process for their creation. To improve the functionality and quality of these valuable biotopes we suggest following set of measures.
1. Sites which are prepared for mining (4a) should be created in several different heights to set up new small water sites and substrates with different granularity (Fig. 21).
2. Sites which are used as deposit places for mining residuals should be not filled up to the top of the banks (usually 3 meters above water level – 7e, 7c). It is better to stop depositing when sandy island is created and shallow water sites are half of the whole area (Fig. 22).
3. The banks dividing smaller parts of the lakes should be low to allow willow shrubs and reeds to develop in the future.
4. By mining and depositing the residuals heterogeneous coastal line should be created (Fig. 23).
5. Under plough-layer material and other not used materials should not be deposited at the slag heaps but used to create different coastal zones.
6. Field depressions, coastal zones and small lakes and pools should be not filled with mining residuals. These residuals should be placed to direct and steep parts of the banks in order to create shallower water. Coastal zones should be 30 cm to 1,5 m deep with maximum of 4° inclination. Low inclination is appropriate in connection with fluctuating heights of the mater levels. Watering the mined material or uneven terrain are advantageous.
To keep and increase the current biological values of most valuable sites we suggest following management.
7. Site 8b (alternatively 7e and dry part with birches at the site 7a) should be kept non-forested and open (primarily the place with occurrence of Labidura riparia). This can be done by occasional crossing of mining mechanization and removing dense vegetation. Recreation can be good management too, especially bathing or a formation of motorcycle track.
8. Site 7f should be kept non-forested with occasional surface disturbances. 9. With a periodicity of several years new pools should be created. At resent, suitable sites are 7b, 7f, 8b and 7a (and possibly other sites at the edges of lakes during creation of littoral zones). The pools can be periodic. In selected pools endangered species of fish (such as Leucaspius delineatus and Carassius carassius) can be raised in cooperation with Nature Conservation Agency of the Czech Republic. Interventions such as disruption of littoral vegetation and small pools should be carried out in the autumn and winter months.
10. Management like coastal zone disturbances and small lake disturbances should be done during autumn or winter.
11. Large species of herbivorous fish species (like grass carp) should be not bred in any water site. In small water sites no fish at all should be bred (with the exception of point 9).
12. In the neighborhood of train sidetrack shrubs should be reduced continuously to provide intense lightening of the site.
13. Grasslands near the railway track (and also all the other ones) should be mowed not at once but by the form of mosaic.
In the future we recommend to do the following management.
14. Separately standing indigenous oak trees should be planted or cleared from the shrub formations and natural seeding forests.
15. Material from 7e site should be spread into the lake I site and material from 7c site (alternatively 8b site) to the lake IV site.
16. Garbage from whole area of the Tovačov sandpit should be removed in order to clear the locality.
17. During forest sorting out of the forests created by non-indigenous tree species (1a, 2c, 3c, 6b a 6d) indigenous and naturally appropriate tree species should be favored. All forest sites should be kept open.
Acknowledgements: Blanka Brandová, Martin Duchoslav, Zbyněk Hradílek, Tomáš Vávra
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List of Appendix:
LIST OF PICTURES AND TABLES: ...................................................................................................................... 11
APPENDIX 1: MAPS ........................................................................................................................................ 12
APPENDIX 2: LIST OF TAXA FOUND................................................................................................................. 24
APPENDIX 3: DATA AND RESULTS OF FIELD STUDIES. ..................................................................................... 41
APPENDIX 4: COMMENTS ON SELECTED FINDS .............................................................................................. 46
Bryophytes (Bryophyta) ................................................................................................................................ 46
Vascular plants (Tracheophyta) .................................................................................................................... 46
Spiders (Araneae) ......................................................................................................................................... 47
Dragonflies (Odonata) .................................................................................................................................. 47
Orthopterans (Orthoptera) and Earwigs (Dermaptera) ............................................................................... 48
Butterflies (Lepidoptera) ............................................................................................................................... 48
Beetles (Coleoptera) ..................................................................................................................................... 48
APPENDIX 5: BIOLOGICALLY VALUABLE SITES. ................................................................................................ 50
APPENDIX 6: IMPLICATIONS FOR MANAGEMENT ........................................................................................... 52
REFERENCES: .................................................................................................................................................. 53
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List of Pictures and Tables:
Figure 1: Specification of studied area and sub-area. ........................................................................................... 12
Figure 2: Specification of sub-sites – zoological part. ........................................................................................... 13
Figure 3: Specification of sub-sites – botanical part. ............................................................................................ 14
Figure 4: Specification of sub-area for field studies. ............................................................................................. 15
Figure 5: Habitats – part Tovačov. ........................................................................................................................ 16
Figure 6: Habitats – part Troubky.......................................................................................................................... 17
Figure 7: Habitats – part Island. ............................................................................................................................ 18
Figure 8: Visualization of the standard deviations of the values of habitats. ....................................................... 19
Figure 9: Interesting findings – plants from Red list in category C2 and C3. ........................................................ 20
Figure 10: Interesting findings – some rare, interesting and selected non-native species. .................................. 21
Figure 11: Interesting findings – Beetles. .............................................................................................................. 22
Figure 12: Interesting findings – Spiders and species from others insect groups. ................................................ 23
Figure 13: DCA ordination diagram analysis without covariates. ......................................................................... 42
Figure 14: Ordination diagram of samples with projected classification into categories of disturbances (S = 0 – without disturbance, S = 1 – with disturbance) with site age shown. .................................................................. 43
Figure 15: Ordination diagram of samples with projected classification into categories of disturbances (S = 0 – without disturbance, S = 1 – with disturbance) with site age shown. .................................................................. 43
Figure 16: Partial DCA analysis of species composition with removing moisture regime of the site. .................. 44
Figure 17: DCA analysis of species composition of spiders. Values were extracted, displaying only species with a higher weight in the analysis................................................................................................................................. 45
Figure 18: DCA analysis of species composition of beetles. Values were extracted, displaying only species with a higher weight in the analysis................................................................................................................................. 45
Figure 19: Fauna at the mining residual site during first stage of succesion. From the left top: Nebria livida, Labidura riparia, Meloe proscarabaeus, Cicindela hybrida, Arctosa cinerea, Cylindera arenaria. ....................... 50
Figure 20: Important plants of uncovered bottoms. Vegetation of Cyperus fuscus in front of reed vegetation. From top left – Alisma lanceolatum, Ranunculus sceleratus, Carex bohemica, Limosella aquatica, Centaurium pulchellum. ............................................................................................................................................................ 51
Figure 21: The appearance of the area prepared for mining. (source: mapy.cz a googlemaps.com). ................. 52
Figure 22: Depositing of mining residuals and its appearance at the end of storage. (source: mapy.cz) ............ 52
Figure 23: The appearance of the coastline. (source: mapy.cz) ............................................................................ 52
Table 1: List of Charophyta, Liverworts and Mosses. ............................................................................................ 24
Table 2: List of Vascular plants. ............................................................................................................................. 24
Table 3: List of habitats in the studied area. ......................................................................................................... 31
Table 4: List of Spiders and Harvestmen. .............................................................................................................. 32
Table 5: List of Dragonflies. ................................................................................................................................... 33
Table 6: List of Butterflies. .................................................................................................................................... 34
Table 7: List of Beetles. ......................................................................................................................................... 36
Table 8: List of other insect groups. ...................................................................................................................... 40
Table 9: List of Amphibians and Reptiles. ............................................................................................................. 40
Table 10: List of Molluscs and Mammals. ............................................................................................................. 40
Table 11: Environmental factors in places of phytosociological plots. ................................................................. 41
Table 12: The marginal effect of each variable on the species composition of the studied areas. Sorted by variables that best explains for the largest percentage of variability to the variable that explains it worse. ...... 42
Table 13: The selection of variables that explains the floristic composition of the plots in the best way and most significantly (forward analysis). ............................................................................................................................. 42
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Appendix 1: Maps
Figure 1: Specification of studied area and sub-area.
14. 13
Figure 2: Specification of sub-sites – zoological part.
15. 14
Figure 3: Specification of sub-sites – botanical part.
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Figure 4: Specification of sub-area for field studies.