Development of soil fauna at mine sites during 46 years after afforestation1

Pedobiologia 45, 243–271 (2001) © Urban & Fischer Verlag http://www.urbanfischer.de/journals/pedo

Development of soil fauna at mine sites during 46 years after afforestation* Wolfram Dunger and Manfred Wanner** with H. Hauser, K. Hohberg, H.-J. Schulz, T. Schwalbe, B. Seifert, J. Vogel, K. Voigtländer, B. Zimdars and K. P. Zulka1 State Museum of Natural History, POB 300 154, D-02806 Görlitz, Germany 1 Institute of Zoology, University of Vienna, Althanstr. 14, A-1090 Vienna, Austria Submitted: 7. July 2000 Accepted: 1. November 2000

Summary At the afforested overburden heap „Langteichhalde“ (lignite mining district Berzdorf, Eastern Germany) a long-term study of the soil fauna (since 1961) was completed by new investigations between 1996-1999 taking microfauna, mesofauna and macrofauna into consideration. Detailed information about the present development of testate amoebae, nematodes, lumbricids, spiders and harvestmen, oribatids, centipedes, millipedes, apterygotes, ants, carabid and staphylinid beetles are briefly compared with the earlier succession of these groups. Generally, both the species inventory as well as diversity points to a change from open landscape communities to woodland associations, albeit in a more or less poor condition. Differences of the settlement depending on deciduous or coniferous afforestation type and surface profile (crests, troughs) are discussed. The contribution of soil organisms to organic matter decomposition was studied by bait lamina tests, the minicontainer technique, and by calculating the potential zootic decomposition level. At the deciduous afforestation the overall soil biological activity reaches the level of natural woodland soils very quickly (after 10 - 20 years), even though based upon the continuing development of soil faunal entities. Primarily coniferous afforestations show an impeded decomposing activity, even if developing in a

* Supported by the German Federal Ministry of Education and Research (BMBF, FKZ 0339668) **E-mail corresponding author: [email protected]

0031–4056/01/45/03–243 $ 15.00/0

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mixed wood. During succession of the mine site community an interesting interrelationship between parts of the soil fauna, especially between lumbricids and microarthropods, can be demonstrated. Key words: Soil micro-, meso-, macrofauna, opencast mining dumps, primary succession, decomposition, minicontainer, bait lamina test

Introduction During the 20th century the increasing demand for energy has led worldwide, but especially in Germany, to the opening of mining areas at dimensions of thousands of km2. One of the outcomes of this cataclysm is the increased number of summarising books on the recultivation of post-mining landscapes at the end of the century (Hüttl et al. 1996, 1999; Pflug 1998; Broll et al. 2000). Concerning the succession of animals, the first worldwide view was edited by Majer (1989). In Germany, two main study centres have been established, the Lower Rhine mining region (Glück 1989; Topp et al., in press) and the Lusatian mining district, divided into Lower Lusatia with its centre at Cottbus (Hüttl et al. 1999) and Upper Lusatia with its centre at Görlitz (Dunger 1968; Dunger et al., in prep.). Stimulations to investigations on the immigration and development of soil fauna at freshly deposited lignite mine spoils goes back to a discussion with Wilhelm Kühnelt at the University of Leipzig in 1956. There were two reasons to take up such studies: From the viewpoint of soil biological ecology the open cast coal mines offered a tremendous experimental field to study soil animals in primary succession and, seen from the viewpoint of recultivation being very poorly developed at this time, knowledge of the soil fauna development was required as an indicator for artificial cultivation techniques. Later on, as a further point of interest, results from the soil faunal development on mine site areas became important for a theoretical approach to primary succession (Dunger & Wanner 1999a). To obtain results fulfilling these objectives, the State Museum of Natural History at Görlitz started a long-term programme for studying the soil fauna at mine sites as early as in 1960. The objectives of this study, continued until 1999, were as follows: – What are the specific characteristics of mine soils as habitats for soil animals and which of the peculiarities of the deposited substrates as well as of the rehabilitation techniques are important for the soil fauna? – Which kind of immigration type is used by the soil fauna and how much time is necessary for the immigration of different taxa? – Which successional direction is taken by the members of the soil fauna and how develop single populations and complex communities? – What is the importance of different kinds of faunal activities in development and differentiation of soil ecosystems at mine soils? – Which role plays the soil fauna in supporting a fast and efficient rehabilitation of mined areas and what are the most adequate human techniques in recultivation to foster this activity?

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The soil faunal studies of the Museum Görlitz started at mine sites at the German south-eastern brown coal mining district of Berzdorf with comparative studies at the mining areas of Lower Lusatia (Dunger 1979) and south of Leipzig (Brüning et al. 1965; Dunger 1969). Within this project, a long-term study of the soil fauna of the overburden heap „Langteichhalde“ (LTH) at the mining district of Berzdorf south of Görlitz was established in 1960. Successive results of this project have been published by Dunger (1968, 1987, 1989, 1997a, b, 1998a, b). This report presents new information from a study between 1996-1999 comprising not only continued investigations up to 46 years following the mine site recultivation but also an extension of the groups studied taking the microfauna (testate amoebae, nematods) into consideration for the first time.

Materials and Methods Study sites The study was carried out mainly at a dump („Langteichhalde“, LTH) of the brown coal open cast mining of Berzdorf (south of Görlitz), Upper Lusatia, Eastern Germany. At this dump (established between 1951 and 1955) the mine site A was afforested in 1952 with Alnus glutinosa, Populus sp. (hybr.) and Robinia pseudacacia, and mine site L with Pinus sylvestris. For comparative purposes, the following test sites were investigated: at the same dump the mine site H, afforested as site A in 1955, the mine site T at an adjacent dump afforested as A in 1959 and the youngest mine site N at a dump 7 km north of site A, afforested with Populus sp. in 1961. Further afforested young mine sites were studied 1997/99 4 km to the west of site A („Innenkippe“, IK). The soil cover on the final dump consists mainly of sands of Pleistocene and Tertiary origin interspersed with lignite sands and dark Tertiary loam and clay. Amelioration was mainly by liming, the pH(KCl) in the upper 10 cm was 5.8 in 1963 decreasing to 5.2 in 1998. Some 15 years after afforestation in mine site A a first woody stage with final soil shading was reached. Results of top soil investigations in 1998 are for site A: humus form L-mull, ectohumus cover 1 cm, Ah 0-10 cm; for site L: humus form moder, ectohumus cover 3 - 7 cm, Ah 0-2 cm; detailed soil characteristics are shown in Table 1.

Table 1. Soil properties of the Berzdorf mine sites A (deciduous afforestation) and L (pinus afforestation tending to a mixed wood). Data for 1963 from Dunger (1968); data for 1998 from Hauser & Kowarsch (1998) and Wanner & Dunger (1999). c= crest, t= trough; x= mean value; a= 0-5 cm, b= 5-10 cm for the 1998 data; a= 0-2 cm, b= 5-7 cm for the 1963 data. SOM= soil organic matter incl. lignite (%), Vp= pore volume (%). The other data from 1998 derived from 0-10 cm soil depth Site date A L

pH(KCl) ca cb

Ct ta

N

S

C/N

tb

1963 5.8 5.9 5.5 4.9 1998 5.1 5.1 4.3 4.2 5.0 0.2 0.001 20.0 1998 5.1 4.1 4.4 4.0 2.3 0.1 0.007 22.0

SOM c t

x

Vp c

t

x

10.6 5.6 8.1 44.1 47.9 46.0 9.9 48.4 4.5 49.8

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Methods Protists and nematodes were sampled in spring and autumn 1997 and 1998 resp. by soil cores (Ø 5cm, 0-5 and 5-10 cm depth, 5 replicates) and examined microscopically using an inverted microscope. Testate amoebae were examined directly (Wanner & Dunger 1999); nematodes were extracted using a modified Baermann-funnel. Edaphic microarthropods („Berlese-fauna“) were sampled at 6 dates altogether in autumn 1997 and spring - autumn 1998 with 50 soil cores (Ø3.5cm) at each of mine sites A and L, divided into 0-5 and 5-10 cm depth and soil profile. There were 12 replicates for crests, and 13 replicates for troughs; the fifth and sixth sampling dates in autumn 1998 are based on pooled data-sets, thus the first four samplings were available for statistical analysis. The animals were extracted by thermoeclectors of a modified Tullgren-type (Dunger & Fiedler (1997). Epedaphic micro- and macroarthropods were collected by pitfall traps (each trap was analysed separately) at 6 dates from autumn 1997 up to autumn 1998 with 9 traps at each of mine sites A and L, divided into soil profiles crests (four traps) and troughs (five traps). These datasets were used for statistical analysis. Additional animals came from area samples and soil macro-cores (see earthworms). Earthworms were calculated on the basis of 60 area samples (0.25 m2, three replicates on the troughs, two replicates on the crests; arithmetic means were used for m2-calculations) using diluted formalin in combination with 80 soil macro-cores sorted by hand (Dunger & Fiedler 1997) at all of mine sites A and L (five replicates on crests and on troughs, Ø 9.5 cm). Decomposition was assessed by two methods: The bait lamina test was used (after Törne 1997) with a bait substance of cellulose (65%), agar agar (15%) and wheat bran (10%). Four test sites (A and L; crest and trough, resp.) with three plots of 16 bait laminas were established. Parallel to the bait lamina, the minicontainer test (Eisenbeis 1998) was carried out by inserting 10 rods each in crests and troughs at each of the mine sites A and L from October 1997 to January 1999. At 6-weekly intervals at each stand one rod, containing 4 minicontainers with 2000, 500 and 20 µm mesh size resp., were removed, the inhabitants extracted by a thermoeclector, and the remaining organic material (poplar litter) weighed. Thus a period of 60 weeks was investigated. Because of the preliminary character of the minicontainer test (low amount of replicates), a detailed statistical analysis was omitted. Litter production was tested by three litter samplers (1 m2 area) at each site A and L between May 1998 and May 1999 being emptied 10 times. For weighing, the litter was dried at 60°C. Additionally the field layer was harvested at 3 plots of each site A and L in May and September 1998. Metabolic equivalent values of lumbricids (MELu) and microarthropods (MEMa), and the respective potential zootic decomposition level (DLZpot) were calculated according to Dunger & Fiedler (1997): ME = B‘ * k * 102 * Y/X where B‘ is the mean biomass (g wet mass m-2), k is the caloric equivalent factor (20* 103 J ml-1 O2), X is the mean living mass per individual (g), and Y is the oxygen consumption (laboratory data, ml O2 ind-1 h-1 at 10°C). From this the potential zootic decomposition level (DLZpot) can be deduced thus: DLZpot=DZpot*100/H where DZpot is the total of ME of an animal group and H is the yearly supply of organic matter measured as annual litter production incl. field layer harvest (KJ m-2 a-1). Analogously, respiratory equivalences (RE) are calculated according to Dunger (1991b): RE=B‘ * 104 * Y/X. Data were evaluated with an analysis of variance (ANOVA; normality was tested with the Kolmogorov-Smirnov test). If input data (as mentioned above) revealed heterogeneous variances (even after transformation) only those factors with P<0.01 were considered, or nonpara-

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metric tests were used (Mann-Whitney test and Kruskal-Wallis one-way analysis of variance). The requirements for statistics were met according to Bauer (1986) and Sachs (1999). The software package SPSS was used for all statistics.

Results Components of the soil fauna – testate amoebae The data presented are based on soil samples (0-5 cm and partly 5-10 cm depth), either pooled (5 soil cores per sampling date, from 1996-1998) to reveal seasonal and successional trends, or counted separately from three or five replicates to provide information about variability within a study site. Generally, small, rapidly reproducing ubiquists (r-strategists) predominated the afforestations (with the exception of Difflugia stoutii Ogden – as far as we know the first record for Germany and the second record since the original description in 1983). During the initial stage, testate amoebae colonised the substrate „additively“, i.e. without replacing other testate amoebae taxa, within a few months. Regarding two up to 46-year-old afforested mine soils (IK, LTH: especially the Pinus sites), a consistent development was observed in the amoebal species inventory (all mine sites: 48 taxa; LTH-L: 35; LTH-A: 36 species), population densities and biomasses in relation to age, substrate and stocking of the afforestations. Abundances and biomasses were of the same order, or even higher, as those described for undisturbed forest soils (e.g. compiled in Foissner 1987). Six out of 48 taxa contributed 61 to 87 % to the mean total amoebal density (26-366 x106 ind. m-2; 0.4-4.8 g m-2; mean values). Species richness increases, as a rule, in the older test sites (Wanner & Dunger 1999, 2001). However, typical humus-inhabiting, large-sized testate amoebae (e.g. Trigonopyxis arcula (Leidy), Hyalosphenia spp., Nebela spp.) were lacking or occurred rarely. With respect to afforestation, abundances and biomasses were remarkably higher in the Pinus afforestations (100-238 x106 ind. m-2; 0.7-3.0 g m-2) as compared to the deciduous sites (47-89 x106 ind. m-2; 0.4-0.9 g m-2; mean values). Species richness, abundances and biomasses on LTH-L (Pinus site) were significantly higher as compared to LTH-A on the second sampling date (deciduous site, P<0.01, Oct. 1998), while the soil surface (crests and troughs) had no influence (P>0.05; nonparametric H-test, for both sampling dates). Meisterfeld (1997) found, as shown in this study, no „typical“ humus-inhabiting species of testate amoebae on reclaimed mine soils in the lignite district of the Rhineland. Only more or less ubiquitous, small species became established. Balík (1996) investigated testate amoebae in the Sokolov coal mine district and described, similarly to our data, a rapid development of the testate amoebae assemblages in the initial stage. Different ages and stages of recultivation are characterised by distinct soil testate amoebae assemblages (Wanner et al. 1998, 1999; Wanner & Dunger 1999, 2001). Components of the soil fauna – nematodes The investigation (for details see Hohberg, in prep.) is based on soil samples (0-5 cm and partly 5-10 cm depth), taken in five replicates in spring and autumn 1998. Generally, nematode density and biomass of afforested Berzdorf mine sites (IK, LTH) were low (0.06 – 1.22 x 106 ind. m-2; 1.9 – 78.1 mg m-2 ), however still within range of

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literature data from natural temperate forest soils. Considering the relatively high densities of testate amoebae mentioned above, it seems improbable that a possible low nutrient supply of mine site soils might cause the rather low nematode densities. We assume that detrimental effects of soil structure, vegetation cover and specific predators (e.g. the tardigrade Macrobiotus richtersi Murray; see Hohberg, in prep.) should be taken into consideration. Altogether, in nine mine soils investigated in spring 1998, 119 species were recorded, belonging to 55 genera. With 56 species (deciduous site A) and 35 species (primarily coniferous site L), species numbers of the 46-year-old afforestations were comparable to those recorded from natural forest soils. Alder afforestations (IK) especially, provided favourable conditions for the coexistence of many species, whereas coniferous as well as poplar plantations resulted in lower nematode diversity. Bacterivores dominated (above all Acrobeloides nanus (De Man) on pine and poplar sites; Plectus spp. and Panagrolaimus spp. on alder sites and deciduous site A). Fungi-/radicivorous species showed higher proportions in site L, whereas obligate herbivorous species were more frequent in site A. Regarding two up to 46-yearold afforested mine soils (especially the pine series) the species inventory (mainly bacterivorous species) and the proportion of bacterivores increased. Neither maturity index nor colonizer persister classes provided a useful bioindication for the long term succession of the Berzdorf mine site ecogenesis. Components of the soil fauna – lumbricids Lumbricid data are based on 60 „formalin samples“ and 80 hand-sorted soil samples (LTH-A, L) taken between autumn 1997 and 1998. The mean population densities and biomasses were in LTH-A 524 ± 193 ind. m-2 / 83.1 ± 38.9 g(wm) m-2 and in LTH-L 218 ± 143 ind. m-2 / 52.7 ± 50.0 g(wm) m-2. Epigeic species were Dendrobaena octaedra (Savigny), which had been recorded since 1961, Dendrodrilus rubidus rubidus (Savigny), since 1985, and Lumbricus rubellus rubellus Hoffmeister, since 1961. Dendrodrilus rubidus was distributed extremely heterogeneously, and adult individuals were totally absent in spring 1998 („L“) and autumn 1998 („A“). More important was L. rubellus, which surpassed 4-6 times („L“) up to 15 times („A“) the biomass of the „Dendrobaena-complex“. Generally, epigeic species shared 37% of the total lumbricid density and 25% of the biomass in „A“ and 61% (ind.) 34% (biomass) in „L“, respectively (Table 2a). Lumbricus terrestris L. is the only anecic species which has occurred at site A since 1966. With respect to its ecological significance, as much as 36% („A“) and 45% („L“) of the total lumbricid biomass and 18% („A“) and 10% („L“) of the total abundances could be ascribed to L. terrestris in 1998. Aporrectodea longa longa Ude was detected only in 1966. Endogeic species have been found since 1961 (Aporrectodea caliginosa caliginosa (Savigny), Aporrectodea rosea rosea (Savigny), and Octolasion tyrtaeum (Savigny)). Two species occurred only occasionally: Allolobophora chlorotica chlorotica (Savigny) in 1966 and Octolasion cyaneum (Savigny) in 1985. Adult A. caliginosa reached higher biomasses than A. rosea, although most individuals of this genus are found in the juvenile stage. All endogeic species reached 40% („A“) and 21% („L“) of the total lumbricid biomass and 45% („A“) and 27% („L“) of the total lumbricid density in 1998 (Table 2a). Total lumbricid densities and biomasses (yielded by formalin extraction) differed significantly between vegetation (note the significant contribution of the endogeic life-forms), but not between soil surface relief (Table 2b). It should be taken into consideration that differences in the

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soil surface (which decreased gradually after dumping) remained more pronounced in the A site. Furthermore, due to considerable variations in densities and biomasses, e.g. in 1997-1998, detailed estimations are difficult, and heterogeneity of the soil substrate produce marked variations in population structure. However, during the first decades of succession, troughs had been clearly preferred by earthworms, especially epigeic life-forms. This (statistically non-significant) trend is still visible in 1999 (Table 2a, b). The observed species inventory (7 persistent species) is typical for disturbed areas and similar to „decomposer communities“ (Graefe 1993). Unsuccessful colonisation attempts of three other species (A. longa, A. chlorotica, O. cyaneum) seem to demonstrate that the ecological capacity is exhausted for the given period. Components of the soil fauna – spiders and harvestmen Pitfall trapping, hand sorting and soil core extraction (see methods) produced 51 species of Araneae and 9 species of Opiliones. Activity density (individuals per trap and week) was highest in troughs of site A, especially with regard to harvestmen (Table 3a, b). The arachnid assemblages of the 46-year-old sites (LTH-L, A) comprised more species as compared to the younger afforestations and differed in species composition. Table 2a. Lumbricids: spectrum of life-forms, mean densities and biomasses (Ind., BM (g wm) m-2). Six sampling dates (Oct. 1997-Oct. 1998), data combined from formalin extraction and hand-sorting. 46-year-old Berzdorf mine sites (LTH-A: deciduous forest; LTH-L: primarily afforested with pine) with crest- and trough-structured soil relief LTH-A crest trough Ind. BM Ind. BM epigeic earthworms Lumbricus rubellus, adult Lumbricus rubellus, total Dendrobaena s.l., total total epigeic anecic earthworms Lumbricus terrestris, adult total anecic endogeic earthworms Aporrectodea spp., total Octolasion tyrtaeum total endogeic

LTH-L crest Ind. BM

Ind.

trough BM

18 8.3 87 18.0 67 1.2 154 19.2

19 6.3 121 19.3 113 2.3 234 21.9

3 1.9 12 12.1 86 2.1 98 14.2

8 4.2 30 17.6 133 4.3 163 21.9

5 20.8 74 30.6

7 15.9 110 29.3

3 9.5 13 19.7

5 14.1 26 27.6

136 23.3 92 9.5 228 32.8

157 24.1 90 8.3 247 32.4

52 10.1 16 0.7 68 10.8

43 10.0 7 1.1 50 11.1

total

456 82.6

591 83.6

179 44.7

239 60.9

share (%) to the total epigeic lumbricids anecic lumbricids endogeic lumbricids

33.8 23.2 39.6 26.2 54.7 31.8 68.2 36.1 16.2 37.0 18.6 35.0 7.3 44.1 10.9 45.5 50.0 39.7 41.8 38.8 36.0 24.2 20.9 18.3

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Table 2b. Lumbricids: Statistical analysis based on data derived from formalin extraction only. “Total” means epigeic, anecic and endogeic species plus indeterminable juveniles from Lumbricus. Differences between surface (crests and troughs) or sites (A, L) are indicated by the level of significance of the nonparametric Kruskal-Wallis H-test total

epigeic

anecic

endogeic

site

Ind BM

0.000*** 0.000***

0.929 0.464

0.069 0.045*

0.000*** 0.000***

surface

Ind. BM

0.507 0.763

0.073 0.242

0.568 0.548

0.786 0.886

Also, the proportion of woodland species (e. g. Bathyphantes nigrinus (Westring), Coelotes inermis (L. Koch)) was higher, those of open landscape species lower, and pioneer species were no longer present. The overall species diversity indicates a relatively poor arachnid community structure as compared to naturally grown woodland. Moreover, the conspicuous presence of several woodland ecotone species (e.g. Trochosa terricola Thorell, cf. Heublein 1983) points to a more or less disturbed woodland species assemblage of the oldest mine site afforestations. Generally, no distinct arachnid species assemblages were visible with regard to site or soil relief (trough or crest). However, some single species apparently preferred humid troughs over the crests (e.g. Gongylidium rufipes (L.), Pirata hygrophilus Thorell), while others, like Diplocephalus picinus (Blackwell), almost exclusively occurred in the deciduous woodland site A. Components of the soil fauna – oribatids Oribatid mites were examined by soil core extraction and, to a lesser extent, by pitfall trappings (see methods). Mean population density at site A (26.5*103 ind. m-2 in 1985; 24.4*103 ind. m-2 in 1997-1998) remained relatively constant in time, while at site L

Table 3a. Arachnids from the Berzdorf mine sites LTH-A, L (see Table1); c=crests; t=troughs Site (LTH)

Ac

At

A

Lc

Lt

L

Araneae (ind. trap-1week-1) Species trapped Add. species by hand sorting total

2.02 21 2 23

4.55 22 5 27

3.43

4.08 27 4 31

3.97 23 4 27

4.02

Opiliones (ind. trap-1week-1) Species trapped Add. species by hand sorting total

7.08 6

12.20 6 1 7

9.93

4.23 7

4.43 5

4.34

7

5

6

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Table 3b. Arachnids from the Berzdorf mine sites LTH-A, L (see Table3a). Results of the two-factorial ANOVA (data transformed) on the effects of „date” (factor 1, six samplings dates) and „surface” (factor 2, crests and troughs). Five replicates on the troughs, four replicates on the crests per site and date, n= 804/1541 (Aran./Opil.) factor Araneae (pitfall trappings) site LTH-A within cells „date” „surface” interaction site LTH-L within cells „date” „surface” interaction Opiliones (pitfall trappings) site LTH-A within cells „date” „surface” interaction site LTH-L within cells „date” „surface” interaction

df

MS

F

Sign. of F

42 5 1 5

0.22 4.32 2.97 0.55

19.76 13.58 2.53

0.000 0.001 0.044

42 5 1 5

0.25 5.61 0.006 0.08

22.83 0.02 0.34

0.000 0.879 0.888

42 5 1 5

1.95 9.67 17.41 4.96

4.96 8.93 2.54

0.001 0.005 0.042

42 5 1 5

1.11 3.21 0.00 1.99

2.89 0.00 1.79

0.025 0.961 0.136

average density decreased (95.4*103 ind. m-2 in 1985; 18.3*103 ind. m-2 in 1997-1998; Table 4a). Oribatid mites, with a total of 90 taxa, indicated a high species diversity. 43 species were common to both sides, while – in low abundance – 21 occurred exclusively on site A and 26 species exclusively on site L. Species inventory, grouped after Beck et al. (1997), points to a relatively cool-humid habitat type for the 46-year old afforestations (Table 4b). The oribatid fauna depends strongly on vegetation and litter quality. In 1962, the population density at the Pinus site L exceeded by 16 times the deciduous site A, and still 3.5 times in 1985. Owing to the increasing proportion of deciduous trees and the decreasing needle litter layer at site L, no striking differences were visible in 1997/1998. Species inventory on the deciduous site A pointed to a more or less open mixed wood habitat type (e.g. Ceratozetes gracilis (Michael), Medioppia obsoleta (Paoli), Galumna lanceata Oudemans), while species exclusively found on the primary Pinus site L are not typical for coniferous habitat types. With respect to soil surface properties, oribatid density was always (but partly nonsignificantly) higher on the crests as compared to the troughs (Table 4a; nonparametric H-test: pitfall traps: P=0.266 (soil surface) and P=0.123 (vegetation); Berlese data: P=0.012** (soil surface) and P=0.931 (vegetation)).

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Table 4a. Oribatid mites, mean densities per soil core (9.08 cm2) and activity-densities derived from pitfall-trapping, Berzdorf mine sites LTH-A, L (see Tables 1, 2) Site (LTH)

Ac

At

A

Lc

Lt

L

Oribatids, total 28.60 17.61 18.92 14.54 Oribatids, size class I (<0.5 mm) 25.55 16.28 23.25 18.34 Oribatids, size class II (<1 mm) 1.25 1.18 1.44 0.42 mean density (m-2) 29516 19185 24351 20837 11476 18282 activity-density (ind. trap-1week-1) 1.81 1.87 1.84 7.54 1.35 4.10

Table 4b. Oribatid mites, species inventory according to higher taxonomic categories, Berzdorf mine sites LTH-A, L (see Tables 1, 2) Site (LTH) Basic low oribatids Peripheral low oribatids Basic higher oribatids Eupheredermata Oppioidea Basic Pterogasterina Total oribatids

LTH-A species 12 11 3 5 16 3 63

% 20.0 18.4 0.2 2.7 15.4 10.4 100

LTH-L species 12 8 1 7 18 5 65

% 28.0 36.3 0.2 3.0 16.1 2.1 100

Components of the soil fauna – centipedes Centipedes (11 species ) were studied by pitfall-traps, soil core extraction, sorting by hand, and minicontainers. At the deciduous site A, activity-density (0.81 ind. trap-1 week-1) was significantly higher than at site L (0.19 ind. trap-1 week-1; nonparametric H-test: P=0.000***). Population densities and biomasses indicated non-significant site differences („A“ with 472 ind. m-2; 0.85 g (wm) m-2 and „L“ with 355 ind. m-2; 0.99 g (wm) m-2; hand-sorting; nonparametric H-test (ind.): P=0.062). In contrast to earlier successional stages, a consistent influence of the surface profile (crests, troughs) on population density was not detectable in 1997/1998 ( hand-sorted material; H-test: P=0.215 (site L); P=0.614 (site A)). With regard to species inventory, Lithobius microps Meinert, 1868 predominated in pitfall trappings, followed by the less frequent Lithobius forficatus (L.). The pioneer species Lamyctes fulvicornis Meinert was completely lacking after 1965 on both mine sites. Four out of 11 species were to be found exclusively at site A, of which three are geophilomorphs (Geophilus insculptus Attems, G. electricus (L.), Strigamia acuminata (Leach)). These subterranean centipedes invade mine sites only after the formation of an at least minimal humic Ahorizon. Furthermore, the first occurrence of Lithobius mutabilis C. L. Koch (see Dunger & Voigtländer 1990) indicates a progressive development from an open landscape to a woodland community.

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Components of the soil fauna – millipedes Millipedes (9 species ) were studied using pitfall-traps, soil core extraction, sorting by hand, and minicontainers. On the deciduous site A, activity-density (2.68 ind. trap-1 week-1) was significantly higher than at site L (0.55 ind. trap-1 week-1; H-test: P=0.000***). At both sites, a remarkably increased activity-density has been observed since 1961/1962 („A“: 0.44 ind. trap-1 week-1; „L“: 0.16 ind. trap-1 week-1). Population densities and biomasses now indicate inconsistent site differences („A“with 201 ind. m-2; 1.31 g (wm) m-2 and „L“ with 110 ind. m-2; 3.06 g (wm) m-2; hand-sorting; H-test (ind.): P=0.066). In 1962, millipedes could hardly be detected by handsorting. Species inventory development has been documented by Dunger & Voigtländer (1990) from 1961. Since 1985/1986, species diversity decreased at site A and remained constant at site L; both sites now display a „deciduous forest-population“ dominated by Glomeris hexasticha Brandt. Other species have been trapped in decreasing density: Julus scandinavius Latzel, Melogona voigtii (Verhoeff), Polyzonium germanicum Brandt, and Unciger foetidus (C. L. Koch). The pioneer species Craspedosoma rawlinsi Leach and Polydesmus inconstans Latzel had been nearly disappeared at this stage. Generally, afforestation by deciduous woodland resulted in a typical diplopod community („A“), whereas primarily coniferous afforestation followed by a succession to a mixed forest caused a relatively species-poor community. The surface profile differentiation in crests and troughs has clearly decreased (especially at site L) since dumping. Thus the observed trough preference in diplopod settlement during the first decades of succession has been diminished with time. In 1997/98, diplopod activity-density in troughs remained higher only at site A (H-test: P=0.0003***; for site L: P=0.2963), and no differences were shown by hand-sorted material (H-test: P=0.936 (site L); P=0.576 (site A)). Components of the soil fauna – apterygotes Springtails (51 species) and proturans (quantitative data only) were sampled by soil core extraction and pitfall-trapping (collembolans only). With respect to collembolan population density, no site or soil surface differences were visible (1997/1998; site A: 28.3*103 ind. m-2; site L: 26.2*103 ind. m-2 (Table 5a, b); the smallest size class predominates. In comparison to the 1985 samples, densities at site A remained constant (27.8*103 ind. m-2), while at site L they decreased slightly (35.9* 103 ind. m-2). With respect to pitfall-trapped epedaphic collembolans, activity in May 1997/1998 was roughly as high as in 1962 or 1985, but decreased more distinctly in autumn. Considering the 1997/1998 data, springtail activity-density displayed, in contrast to most other tested groups, no significant site differences („L“, „A“; Table 5a, b). Proturan density had decreased since 1985 on both study sites (1985/ 1997-1998: „A“: 2533/ 666 ind. m-2; „L“: 2670/ 732 ind. m-2). Collembolan species inventory revealed remarkable successional changes. Some edaphic springtails remained eudominant (Parisotoma notabilis (Schäffer), Mesaphorura macrochaeta Rusek, M. hylophila Rusek, and M. tenuisensillata Rusek), but formerly recedent species now became predominant (e.g. Isotomiella minor (Schäffer), Megalothorax minimus Willem, Protaphorura armata (Tullberg), Stenaphorurella quadrispina (Börner), or Folsomia manolachei Bagnall). Characteristic species of typical associations for younger successional stages decreased considerably (e.g. Proisotoma minuta (Tullberg), Micranurida pygmaea Börner, Isotomodes productus (Axelson)), or disappeared completely. As for

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edaphic collembolans, epedaphic taxa have undergone considerable changes in species composition within the last 46 years. Dominant and characteristic species of earlier stages, such as Lepidocyrtus paradoxus Uzel, L. cyaneus Tullberg, Tomocerus vulgaris (Tullberg), Entomobrya multifasciata (Tullberg), Hypogastrura succinea Gisin, and H. assimilis Krausbauer have been replaced by Tomocerus flavescens (Tullberg), Orchesella flavescens (Bourlet), and Sminthurinus aureus (Lubbock) in 1997/1998. The observed changes in species composition indicate a replacement of an open landscape community to that of a woodland. Typical sylvan species, such as Neonaphorura dungeri Schulz, Deuterosminthurus bicinctus (Koch), Dicyrtoma fusca (Lubbock), or Arrhopalites sericus Gisin, appear now. Furthermore, differences in species composition of sites L and A have been diminished during time in accordance with the development of „L“ to a mixed forest. With respect to collembolan population density, crests and troughs seemed to be colonised differently by epedaphic collembolans, while no site differences for edaphic (0-5 cm soil cores) or epedaphic springtails were visible in 1997/1998 (Table 5a, b). Furthermore, some species clearly preferred deeper soil layers (e.g. Oligaphorura serratotuberculata (Stach)). Components of the soil fauna – ants Ant data are primarily based on nest records („A“: 29.9 nests 100 m-2; „L“: 24.5 nests 100 m-2), and to a lesser extent on pitfall-trappings and soil cores. At site A, seven species were found, at site L only four. As first observed in 1985, the findings of 1997/1998 confirm that open landscape-preferring pioneer species (Formica cinerea Mayr, Lasius niger (L.), Tetramorium impurum (Förster)) are replaced by sylvan species. The recent woodland community is typical but poor in species, especially with regard to site L, where Lepidothorax spp. (normally common in Pinus forests) are totally lacking. This might be caused by the extraordinary dense field layer, keeping the soil temperature at a low level. Species that are found by trapping only (Formica cinerea, Lasius niger) are assumed to be invaders from adjacent areas, while Myrmica

Table 5a. Apterygotes, mean densities per soil core (9.08 cm2) and m2; and activitydensities derived from pitfall- trapping, Berzdorf mine sites LTH-A, L (see Tables 1, 2) Site (LTH) edaphic Collembola, total (soil core-1) size class I (<0.5mm) size class II (<1 mm) size class III (< 2mm) edaphic Collembola, m-2 epedaphic Collembola (ind. trap-1week-1) Protura, total (size class I only) Protura, m2

Ac

At

24.12 21.26 2.86 –

27.29 23.68 3.57 0.04

14.0

17.4

0.47

A

28309 15.9

0.74

Lc

Lt

22.88 20.35 2.50 0.03

24.66 22.18 2.39 0.09

9.7

18.1

0.96 666

L

26178 14.3

0.37 732

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255

Table 5b. Collembola, mean densities per soil core (9.08 cm2) and m2; and activitydensities derived from pitfall- trapping, Berzdorf mine sites LTH-A, L. Results of the nonparametric ANOVA (Kruskal-Wallis H-test) on the effects of „surface” (crests and troughs) and „site” (LTH-A, L). Soil cores: four sampling dates with 12/13 replicates per crest/trough. Pitfall trappings: six sampling dates with 4/5 replicates per crest/trough Epedaphic Collembola (pitfall trapping) „surface” (site A) P= 0.924 „surface” (site L) P= 0.197 „site” P= 0.890 Euedaphic Collembola (soil core extraction) 0-5 cm „surface” (site A) P= 0.544 „surface” (site L) P= 0.349 „site” P= 0.900

5-10 cm P= 0.741 P= 0.037* P= 0.003**

rubra (L.), M. ruginodis Nylander (predominating at site „L“), Lasius platythorax Seifert, L. flavus (Fabricius), and Stenamma debile (Förster) are also found in nests. Generally, ants are known to depend principally on epigeic habitat structures, and do not indicate the developmental stage of the soil. Components of the soil fauna – carabid and staphylinid beetles Ground beetles (site A: 21, site L: 19 species) and rove beetles (site A: 37, site L: 41 species) were examined using pitfall traps and hand-sorting. Activity-density (individuals per trap and week) of carabids (site A: 4.45, site L: 2.68) and staphylinids (site A: 4.37, site L: 2.48) was always highest at the deciduous afforestation „A“ (H-test, P=0.009** (Carabidae, ind.) and P=0.002** (Staphylinidae, ind.)). In comparison to the investigation period of 1985 (Vogel & Dunger 1991), at both sites the eurytopic wood-inhabiting ground-beetles Carabus nemoralis Müll. and Pterostichus oblongopunctatus (F.) decrease, and the hygrophilic Leistus terminatus (Hellwig) appears for the first time, becoming subdominant. Additional conspicuous replacements of species point to a change from an open landscape community to a woodland association. In accordance to the change of site L from a Pinus afforestation to a mixed forest, species inventory adjusted to site A, but some characteristic dominant species remained at both sites (site A: e.g. Carabus hortensis L.; site L: Ocalea badia Er., Staphylinus erythropterus L.). Contribution of soil organisms to decomposition of organic matter The most important developmental process in mine site soil ecosystems is the formation and the decomposition of organic matter. In this context, the vegetation development of the Berzdorf mining district is referred to by Dunger (1968); Dunger & Wanner (1999b) and Dunger et al. (in prep.). According to the vegetation growth, the yearly amount of dead organic matter fluctuates during mine site succession. That can be shown by the evaluation of the above soil primary net production (except that of the woody standing crop) measured

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as yearly litter production and field layer crop (Table 8). In 1998, the woody share of litter was 34.7% at mine site A and 25.0% at mine site L; in the latter the needle litter amounts to 56.7% of the total. As an integrated approach to study litter decomposition the bait lamina test was introduced by Törne 1990 (Larink & Kratz 1994; Dunger & Fiedler 1997). It indicates primarily the biological activity in the litter layer and the upper soil layers, mainly involving both the participation of soil microorganisms as well as soil invertebrates. The bait lamina test informs about relative overall biological activities within and between distinct test plots. In 1997 - 1998, bait lamina strips were exposed three times at four test sites: crests (Ac) and troughs (At) at deciduous mine site A and crests (Lc) and troughs (Lt) at mixed woody mine site L. The results (Table 6) showed that the overall biological activity was greater at troughs than at crests, especially at the L mine site. Otherwise, biological activity is slightly higher at the L mine site in comparison with the deciduous site A. Furthermore, the biological activity decreases more quickly with the depth of soil layers at L mine site than at A mine site (Fig. 1).

Table 6. Results of bait lamina tests. Total feeding activity in % for a 10 days period; Ac, At crests and troughs resp. at mine site A; Lc, Lt at mine site L, respectively; P = level of significance, Kruskal-Wallis-H-Test Site (LTH)

Ac

At

Lc

Lt

P

October 1997 May 1998 September 1998 Mean (%)

27.5 22.5 20.2 23.4

16.5 28.5 41.9 29.0

11.0 21.9 30.8 21.2

47.1 32.4 47.6 42.4

0.037* 0.161 0.029*

The minicontainer test method was introduced by Eisenbeis (1994) as a refined litter bag test to study the rates of decomposition of a test material under different participation of soil fauna. Preliminary minicontainer tests were established at the four bait lamina test sites from Oct. 20th, 1997 to Jan. 4th, 1999. The decomposition was nearly completed in this period in minicontainers with 2 mm mesh size (participation of at least the whole soil fauna), reaches about 50% in minicontainers with 500 µm mesh size (participation of the meso- and microfauna) and about 40% in minicontainers with 20 µm mesh size (expected main participation of the microfauna only; Fig. 2). Soil microarthropods play an important role in decomposing the poplar litter within the minicontainer bags. They invade the bags in such numbers that up to 130 animals (an average of about 10 animals) were found in one bag with 250 to 125 mg dry mass of litter (Table 7). A concentration of microarthropods to such an extent has never been found in natural litter layers. Therefore we suppose that within the minicontainer bags abnormal conditions of decomposition arise. Collembolans invade the bags in by far the highest numbers (79.5% of the total), followed by parasitiforme, trombidiid and oribatid mites as well as small-sized millipedes. Furthermore, the results show that the objective of using different mesh sizes to exclude the macrofauna (by 500 µm mesh size) and the mesofauna (by 20 µm mesh size) has not been fully reached as small springtails (predominantly Folsomia candida) settle the 20 µm bags

Soil fauna at mine sites

257

after some 6 months in very high numbers. All the other groups of microarthropods were very seldom found in the 20 µm bags and largely prefer the 500 µm bags. Possibly the settlement of the minicontainer bags by microarthropods can be used as an indication of decomposition intensity. Up to 24 weeks after exposure the attractiveness of the containers rises significantly for large and medium mesh size types. Only 6 weeks later, very suddenly, a settlement of the 20 µm containers arises mainly through collembolan invasion. This leads to a more intensive decomposition in containers of this type and a decrease in microarthropods in containers with medium and large mesh size. This is corroborated by the nearly total decomposition of litter in 2 mm mesh containers, which is hardly to be seen in the 500 µm mesh containers. The role of collembolans and their ability the overcome the 20 µm barrier is discussed by Dunger et al. (subm.). Another possibility for estimating the role of soil fauna in decomposing the dead organic matter is to calculate the potential zootic decomposition level (DLZpot) after Dunger & Fiedler (1997) from the quotient of the metabolic equivalence (ME) and the above soil net primary production excluding the wood (see methods). The ME of lumbricids increases continuously at Berzdorf mine sites under deciduous afforestation up

Fig. 1. Mean feeding activity revealed by bait-lamina (0-8cm) from four test sites at the Berzdorf mining district; test period May 15th to June 4th , 1998. A= deciduous afforestation; L= primarily pine afforestation; c= crests; t= troughs. Each test site consists of three plots of 16 bait-lamina

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Fig. 2. Kinetics of litter mass loss. Minicontainers with different mesh sizes, implanted horizontally into the soils (5-8cm cm depth, following the Ah horizon) of the 46-year-old mine sites A (deciduous wood) and L (mixed wood) of the Berzdorf mining district. Exposed between Oct. 24th 1997 and January 4th, 1999

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Table 7. Invasion of soil microarthropods into minicontainers with poplar litter at Berzdorf mine sites A and L during 14 months date 01.12.97 12.01.98 23.02.98 06.04.98 18.05.98 29.06.98 10.08.98 21.09.98 02.11.98 04.01.99 total ind. container-1

numbers of animals with respect to different mesh sizes 2 mm 500 µm 20 µm total collembola 67 74 74 99 155 226 185 126 107 117

68 87 21 133 161 254 450 182 197 157

2 17 18 16 34 286 525 415 514 487

137 178 113 149 350 766 1160 723 818 761

27 78 75 115 202 636 1051 614 742 642

1230 7.7

1710 10.7

2314 14.5

5254 10.5

4179 8.7

to an age of 33 years, but decreases slightly at the 46 year level. At mine site L which started as a coniferous afforestation and changed into a mixed wood within 20 years, the lumbricid ME increases more slowly up to 46 years. At deciduous sites, the ME values of microarthropods reach very quickly the highest level (pioneer optimum after 3 years), decrease up to the tenth year and than increase again to a similar level between 33 and 46 years. At the mixed coniferous site L the microarthropod ME values start at a very high level and rise again up to 33 years but decrease later up to the 46 years age (Table 8). The calculation of DLZpot as shown in Table 8 is incomplete because it is based on lumbricids and microarthropods only. Furthermore, the saprophagous macrofauna and the enchytraeids, as well as the microfauna, are expected to make an appreciable contribution to decomposition. The macrofauna and enchytraeids have not been studied with methods adequate enough to be included in the calculation; for the microfauna there is no experience for doing so. However, as DLZpot values are guideline data, i.e. not for drawing up a balance sheet, the values based on lumbricids and microarthropods only are sufficient to estimate the development of the faunal potency in decomposition. The results (Table 8) indicate that the soil fauna needs, under good conditions (deciduous woodland) some ten years to reach a decomposition efficiency comparable to natural sites. This process was impeded at the coniferous afforestation (site L) for over 46 years, although it had changed into a mixed woody stand (L46) in the meantime. Interrelationships between soil faunal components Within the process of new formation of habitats after the technical deposition of lignite mine spoils there are not only interactions between immigrating animals and abiotic life conditions, but to a great extent interrelationships between species with different abilities to use the actual life situation. In this context, dispersal potency seems to play a minor role compared to the ecological potency of the species.

35 659 0.0 5.16 5.16 100 0.78

442 8328 0.39 33.29 33.68 98.8 0.40

T3 327 6161 79.76 22.04 101.80 21.6 1.65

H7 282 5313 401.33 8.91 410.24 2.2 7.72

A10 n.d. n.d. 56.77 51.58 108.35 47.6 n.d.

L10 n.d. n.d. 901.96 25.98 927.94 2.8 n.d.

A33

A46

n.d. 570 n.d. 10739 377.15 781.06 78.26 22.84 455.41 803.90 17.2 2.8 n.d. 7.49

L33

468 8818 504.66 21.15 525.81 4.0 5.96

L46

24.2

36.9 4.9 25.7 26.8 5.6

%

100

8.9 1.2 6.2 6.5 1.4

Collembola Protura Oribatida Trombidiformes Parasitiformes

Total

1962 A10 D

Year Site Density/Dominance

122.5

6.5 – 102.0 12.2 1.8

% 5.3 – 83.3 9.9 1.5

100

1962 L10 D

84.6

27.8 2.5 26.5 18.3 8.6

% 32.9 2.9 31.3 21.6 10.1 100

1985 A33 D

233.2

35.9 2.7 95.2 87.6 11.3

% 15.4 1.2 40.8 37.6 4.8 100

1985 L33 D

72.2

28.2 1.9 26.8 4.9 8.2

% 38.9 2.6 37.1 6.9 11.4 100

1998 A46 D

64.0

27.9 2.4 20.2 2.9 7.2

% 43.6 3.8 31.6 4.6 11.2 100

1998 L46 D

Table 9. Relationships between groups of microarthropods during the development of two mine sites (A deciduous wood, L coniferous developing to mixed wood) of Berzdorf open cast mining district during 46 years. D= density (1000 ind. m-2); % = dominance percentage

litter (g dw m-2 a-1) litter (kJ m-2 a-1) MELu MEMa MELu+Ma MEMa : MELu % DLZpot (Lu+Ma)

N1

Table 8. Yearly litter production, metabolic equivalent values of lumbricids (MELu) and microarthropods (MEMa) and potential zootic decomposition level (DLZpot) of lumbricids and microarthropods in Berzdorf mine sites (see methods; numbers behind site initials mean the years after recultivation)

260 Wolfram Dunger et al.

Soil fauna at mine sites

261

Table 10. Relationships between genera of lumbricids during the development of Berzdorf mine sites over 46 years. Age = years after afforestation, mean = mean total biomass (g wm m-2), site see „study sites“ Age

site

mean biomass biomass (%) Aporrectodea Dendrobaena, Lumbricus Octolasion Dendrodrilus

deciduous afforestations 2 N 0 3 T 0.14 100 5 N 2.3 100 7 H 6.7 44.0 10 A 40.6 62.7 14 A 49.5 27.9 33 A 104.2 49.2 34 A 83.2 44.3 46 A 83.1 28.6 primarily coniferous afforestation 10 L 4.5 12.7 33 L 38.2 20.4 34 L 41.3 34.5 46 L 52.8 19.2

53.0 10.6 2.3 2.1 1.0 2.0

0 24.6 64.5 47.4 54.7 58.6

3.0 2.1 5.3 1.3 0 10.8

87.3 3.8 2.9 6.1

0 74.7 62.0 72.9

0 0.9 0.6 1.8

Table 11. Comparison of the developmental stages of lumbricids and microarthropods (measured as respiratory equivalences per m2 = RE, see methods) at Berzdorf minesites 2 to 46 years after the afforestation. Age = years after afforestation, site see „study sites“, n.i. = not investigated deciduous afforestations Age site RE lumbricids RE microarthropods

site

1 3 7 10 33 46

L L L L L L

N T H A A A

0.0 0.05 9.25 47.93 107.73 95.15

0.56 3.92 2.80 1.12 3.36 2.96

primarily coniferous afforestation RE lumbricids RE microarthropods

n.i. n.i. n.i. 6.78 45.05 56.71

n.i. n.i. n.i. 6.16 9.52 2.59

With respect to the microarthropods, Collembola, Oribatida and trombidiid mites are the most important immigrators into young mine sites. Their relative development within the different mine sites clearly depends on the specific conditions (Table 9). The oribatids dominate at the 10 years old L mine site in the pure Pinus-needle litter, but take second place, behind Collembola, 36 years later in the mixed deciduous and needle litter at the same site. Even in this case, as well as generally at the A mine site, the proportion of the oribatid density approximates that of the Collembola, which general dominate at A mine site and at L mine site in 1998. Only the trombidiid mites

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have a comparably high share of the density at A mine site in 1962 and 1985 and at L mine site in 1985. The parasitiforme proportion, esp. Gamasida, is comparable on the older sites with mull humus (A 33+46, L46), but their absolute abundances were highest at L33 with mixed raw and moder humus. This stage bears the highest microarthropod density. The development of the lumbricids at the mine sites A and L is a meaningful example of the interrelationship of genera within a family (Table 10). Under the condition of nutrition with deciduous litter the detectable settlement of lumbricids started at mine site A in the fourth year with Aporrectodea caliginosa, soon followed by Dendrobaena octaedra. After 10 years the population is dominated by Aporrectodea caliginosa (with small amounts of A. rosea), sharing with Lumbricus rubellus (25%) and Dendrobaena octaedra (11%). Only 4 years later the proportions between Lumbricus (now with L. terrestris as well) and Aporrectodea is reversed, indicating a high advantage of the nutrition from the surface of the litter layer. Later on the proportion between these genera realigned again. The genera Dendrobaena/Dendrodrilus and Octolasion play a minor role during the whole development. Other conditions prevail at site L with primarily strong raw humus formation. The first coherent populations were built up by Dendrobaena octaedra, which continues to be dominant (with the participation of Dendrodrilus rubidus) over nearly 30 years, proving the predominant influence of an exohumus layer at this site. After 33 years, and later on, the genus Lumbricus (already with a major proportion of L. terrestris) clearly dominates at site L, too. Up to the last investigation (46 years) the Aporrectodea density is relatively small, but clearly greater than that of the genera Dendrobaena/Dendrodrilus and Octolasion, the latter showing only a minor presence. The succession of the lumbricid genera and species demonstrated above may be generally caused by the ecogenesis of the studied mine sites (Dunger & Wanner 1999a). Additionally, interrelationships between species and groups of animals play an important role. It may be conceivable that the incorporation of ectohumus into the mineral soil layer by anecic earthworms results in deprivation of the epigeic forms of their habitat and nutrition. Even more interesting is the question whether there are interrelationships between members of the macrofauna and the mesofauna during succession. For quantitative comparisons, neither population densities nor biomasses are suitable, but the basal respiration at 10°C related to the individual weight multiplied by the average biomass per m2 (RE = respiratory equivalence). The successional comparison in earthworms and microarthropods based on RE values (Table 11) at site A shows that the energetic capacity of the microarthropods (especially Collembola and Oribatida) rises very suddenly during the first three to five years, but is then outstripped and depressed by the development of the earthworm population and the diminution of the litter layer. The microarthropods need some 20 years (more exact intermediate studies are required) to overcome that depression. During this time a basal change of the communities occurs (Dunger 1991a; Dunger & Wanner 1999b). A retroaction on the development of the earthworm communities can not be proved from the facts known at present. The same applies to the primary coniferous site L, but with a retarded influence of the earthworms (not earlier than the tenth year) because of the poor palatability of the needle litter for most lumbricids. Thus, the microarthropods starting on site L with

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263

double the intensity compared to site A, show nearly no reaction against the limited earthworm activity, because the exohumic situation is altering to a lesser extent and over a longer period than in deciduous humic stands. After 46 years the humus layer seems to get an adequate quality for microarthropods as on site A. That is corroborated as well by the approach of the energetic capacity of the earthworm population at site L to that at site A in this time. The presented development of the interrelationships between earthworms and microarthropods can be derived as well from the quotients of microarthropod and lumbricid metabolic equivalences (ME) listed in Table 8. At deciduous stands the quotient starts with nearly 100%, decreases in the „contact time“ down to 22% and reaches a low (2.2%) as soon as after 10 years. At primarily coniferous stands this succession takes more time and comes to a low as late as after 46 years.

Discussion Mine site features A detailed knowledge of the geological substrate as well as the type of equipment used in mining is a prerequisite for comparisons of faunal succession at strip mine dumps. The older Berzdorf spoils had been dumped half a century ago with a primitive technology, thus distinct cover materials supporting reclamation are lacking. Reclamation-supporting mining technologies, as are usual at e.g. the Rhineland open-cast mining district (Dworschak 1997; Topp et al., in press), are generally claimed since 1980 by the Federal Mining Act as a „bed of arable land“ to the depth of 0.6-1.0 metres of topsoil (Hildmann & Wünsche 1996). On the other hand, the Berzdorf top soil substrates which are mixed materials from very different strata of the overburden, are not as highly contaminated by pyrite and marcasite as those materials used at the Central German or Lower Lusatian mining districts (Hüttl et al. 1996). The severe problems of sulphur acidification detrimental for plant and animal immigration (Brüning et al. 1965; Dunger 1969, 1979; Dunger et al. 1997a, b; Keplin & Hüttl 1999) are not typical for the Berzdorf opencast district. Another point to bear in mind if comparing mine site development is different human activity. A ‚pure‘ natural succession is described rarely (Jochimsen 1996), investigations on succession on afforestation after amelioration or agricultural utilisation are more usual (Curry & Cotton 1983; Rushton 1986;Wermbter 2000). The Berzdorf mine sites have received only a minor amelioration (mainly liming) and virtually no forestry maintenance since plantation. An important condition, at least for the first years of renaturation /recultivation, is the surface quality caused by the dumping technique. The using of stackers or primitive railborne techniques with tipper lorries, as used at the Berzdorf dumps, frequently resulted in long stripes of crests and troughs. As emphasized also by other authors (Topp et al., in press), Dunger (1968, 1989) found at Berzdorf dumps the earliest settlement and development of vegetation and fauna in troughs, virtually based on lower temperature extremes, a more constant moisture, a finer soil texture and higher contents of organic matter. Today, forty years later, the micro-climatic differences between troughs and crests are less pronounced, because differences in altitude became

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equalized by erosion, whereas the higher quality of soil texture and organic matter concentration in troughs remain to some extent (Dunger et al., in prep.). Thus the ecological preference of the soil fauna towards troughs is less pronounced than expected, even though some indication is still given today (Wanner & Dunger, subm.). Immigration and development of the soil fauna The up-to-date results on the investigation of the faunal succession in the Berzdorf mining district (Dunger & Wanner 1999a, b;Wanner et al. 1998; Wanner & Dunger 1999) lead to the conclusion, that natural immigration by air-, water- , material-transport, or active locomotion ensure the settlement of nearly all groups of the soil fauna depending on the dump top soil quality. These studies support earlier observations of the „arthropod fallout“ (Crawford & Edwards 1986; Klausnitzer 1993) as an important source of mine area settlement. Experimental application of (faunated) woodland top soil and litter (Glück 1989; Wolf 1985) had, with respect to soil fauna, no clear beneficial effects. In some cases, the introduction of suitable species of earthworms succeeded in acceleration of soil biological processes, esp. in stabilising aggregates and increasing soil microbial biomass (Scullion & Malik 2000). However, such effects have also been shown at dumps without inoculation of earthworms or other components of the soil fauna, and even are to be demonstrated under the hampering influence of pyrite substances (Keplin et al. 1999; Wermbter 2000). The soil profile investigations (Dunger & Wanner 1999b), as well as the decomposition study (Figs. 1, 2), confirm an equivalent development of the soil biological processes at the Berzdorf mine sites. This conclusion is corroborated by the quantity and species composition of the soil fauna. The earthworm communities established on the Berzdorf mine sites are comparable with those of the forest reclamation areas of the Rhineland mining district (Topp et al. 1992), as well as with different tree plantations (Quercus, Tilia: Topp et al., in press; Dworschak 1997, with additional Lumbricus castaneus), under agricultural reclamation (without epigeic earthworms, Westernacher-Dotzler & Dumbeck 1992), or even with colliery spoil heaps at Durham (additionally with Lumbricus festivus, Standen et al. 1982). As this can be expanded to communities from North German fallows (Bessel & Schrader 1998), as long as the area of distribution of peregrine species only (Brauckmann et al. 1995) is not exceeded, it seems that it concerns a „community of disturbed areas“. The long-term observations on Berzdorf mine sites confirm a varying presence of species such as Allolobophora chlorotica or Aporrectodea longa, a process that corroborates the conditions postulated by den Boer (1981) for heterogeneous and variable life situations. Only the unstable participation of Octolasion lacteum is not understandable by these reflections. In this context, it should be examined to which extend the soil genetical circumstances are realised as demanded by Höser (1994) for settlements of this species. The well known influence of long-term changing of climatic factors on the earthworm species spectrum (Scheu 1992) was not recorded in our studies, because the samplings during a 2-3 years period were not dense enough. Similar assessments, as demonstrated for earthworms in the present study, can be easily applied to other groups of the soil fauna (Dunger & Wanner 1999b). In spite of the importance of soil Protozoa and Nematoda with respect to general ecology and bioindication (e.g. compiled in Darbyshire 1994; Freckman 1982), most

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studies on mine site recultivation and succession have not considered the soil microfauna at all. As shown in our study, microfaunal (e.g. testate amoebae and nematodes) diversity and community development present valuable information about the status of soils in ecogenesis. Testate amoebae as well as nematodes occur early (within a few weeks) on freshly deposited mine dumps (Wanner et al. 1998), developing into sitespecific populations within a short time span. Compared to plant succession of spoil soils, the changes in the nematode communities occur considerably faster. Therefore Bongers & Bongers (1998) argue that „each characteristic successional stage offers the nematode fauna enough time to develop towards the climax community that is typical for that vegetation type“. In conclusion, expanding our knowledge on microfaunal primary succession (e.g. on coastal dunes: Goralczyk & Verhoeven 1999), it becomes obvious that the role of the microfauna has definitely to be considered in further studies on ecosystem functioning and primary succession. Action of the soil fauna in ecogenesis of mine sites Due to determination problems of soil organic matter (SOM) caused by a varying lignite content of the spoil substratum, continuous studies on SOM are not available. Comparing the soil quality of the first years of succession (Dunger 1968) and after 45 years (Hauser & Kowarsch 1998; Kobel-Lamparski & Lamparski 1999), it can clearly be concluded that the profiles of the studied mine sites are structured by earthworm activity. In contrast to the findings of Topp et al. (in press) from Rhineland spoils, the pH values remained at the same level or even decreased slightly (Table 1). The influence of the growing woodland can be derived from the litter production (Table 8). As stated by other investigations from mined areas (Felinks et al. 1999; Wiegleb et al. 2000), the developing of the vegetation is the main factor for changes in species composition. Table 10 shows the varying contribution of earthworm species at the Berzdorf mine sites. The participation of the epigeic Dendrobaena octaedra mainly during the first years at mine site L can not only be seen as an indication of a strong litter layer upon the mineral soil but also as a distinct qualitative influence on decomposition. Scheu & Parkinson (1994) found that this species increases the leaching of nutrients and reduces the microbial biomass at least in decomposing N-rich aspen litter. As for the dominating anecic Lumbricus terrestris, recent studies (Daniel 1991) corroborate the old knowledge (Dunger 1964) of a high leaf-litter consumption. The development of the earthworm community at the studied mine sites may indicate the biological soil condition. Using strategy-types proposed by Graefe (1997), the predominating combination between anecic and mineral forms with only a few epigeic ones is typical for fresh to wet loamy soils. Taking this into consideration, spoil soils (with the minor influence of pyrite or marcasite) are little different from natural ones, at least for the meso- and macrofauna. The contribution of soil animal groups other than earthworms in the development of soil structures, decomposition and nutrient cycling is also obvious from the results but less discernible. At the end of the pioneer optimum (7th to 12th year at mine site A; Dunger 1989) the increasing activity of anecic earthworms (Lumbricus terrestris) significantly affects the ectohumic litter layer and thus destroys the habitat of most of the microarthropods (esp. oribatid mites and springtails). In the primary coniferous

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site L the process went on for about twenty years. Additionally, a pronounced decrease in density of these groups occurred (Table 9), thus resulting in an obviously negative effect on the earthworm populations. On the other hand, from the burrowing activity and the humic walls in the drilosphere, a positive influence might have been expected (Tiunov & Scheu 1999). Direct interrelationships between earthworms and microarthropods, as shown by Scheu et al. (1999) in experimental systems, indicate differences in the reaction of edaphic and epedaphic Collembola. Correspondingly, the succession process on Berzdorf mine sites proceeds independently for edaphic and epedaphic communities of Collembola (Dunger 1991a). The details of the transfer of experimental results into field conditions, especially concerning the incorporation of the terrestrial detritivore system into the complex trophic interactions (Gange & Brown 1997), are still poorly understood, insufficient for more far-reaching presumptions. The same applies to presumable interactions (Alphei et al. 1996) between Protozoa and Nematoda with the soil meso- and macrofauna. More details will be presented in Dunger et al. (in prep.). The decomposition tests (bait lamina, minicontainers) were expected to show a higher biological activity at the deciduous mine site A. This could not be proved. Surprisingly, the minicontainers not only exhibited an extreme „litterbag effect“ (Crossley & Hoglund 1962), but also the highest collembolan density in the containers with 20 µm mesh size which were expected to be free from mesofauna. It is important to know that these high densities occurred as late as 7 months after starting. After this time Folsomia candida, being nearly absent at samples from soil cores, invades the containers filled with poplar litter up to 600 specimens per g dry mass. It is supposed that newly hatched instars had been attracted by the decomposing litter and were able to penetrate the gauze, but after increasing in body size could not escape again (Dunger, Schulz & Zimdars, subm.). Keplin (1999) found at reclaimed pine mine sites with the same technique, but with Pinus sylvestris root litter and a shorter observation time, 55 specimens per 1 g litter at maximum. However, assessing decomposition by this method may not be suitable to reveal values typical for the investigated stand (Törne 1997). The meaning of soil fauna for a „good restoration“ Finally, it may be asked for the meaning of the soil fauna in the discussion about „good ecological restoration“ (Higgs 1997), nowadays considered in a broad context (Hüttl et al. 1996, 1999; Pflug 1998; Broll et al. 2000; Wiegleb et al. 2000; Topp et al., in press). The goal is a self-sustaining rehabilitation (Langkamp et al. 1979), finally reaching the „original ecosystem“, i.e. a full restoration approaching the „preturbation point“. This is seldom achieved and the more frequent alternative approach is the replacement by another system (Majer 1989). The importance of the soil fauna in the primary succession process to improve the soil structure and enhance decomposition and nutrient cycling is briefly described in the present case study „Berzdorf mines“. The questions remain whether a typical, „preturbation“ composition of the soil fauna has to be demanded or even claimed, as it is in case of the vegetation cover or bird community, to fulfill the claims for a „good ecological restoration“. With the progress in soil zoology, this goal is not an illusion, but rather a possibility to proof the self-sustaining condition of the ecosystem. We know not only for the earthworms (Graefe 1993) but more precisely for microarthropods (Dunger 1991a; Beck et al. 1997) that

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„decomposer communities“ with regional differentiations may have characteristic species compositions depending on soil properties such as texture, moisture etc. (Römbke & Dreher 1999). Thus, we can conclude that the soil faunal development at the studied mine sites of Berzdorf fulfills the demands for a good ecological restoration at least for the deciduous site A, despite a very bad and irregular mineral composition in the cover layer of the dump. In contrast, our investigations on a 35-year-old pyrite-rich lignite spoil at Domsdorf (Lower Lusatia), afforested with Quercus rubra and Tilia cordata, resulted in a very poor soil fauna, partly caused by planting exotic oaks and exhibiting a „bad ecological restoration“ (Dunger 1997b).

Acknowledgements We thank Dr. Beate Keplin for supporting our decomposition study. Prof. Dr. W. Xylander encouraged us with beneficial discussions and institutional help. The technical assistance of Kerstin Franke, Marlis Römer, and Heiderose Stöhr is gratefully acknowledged. This study was financially supported by the BMBF (#0339668; the responsibility for the content of this publication is taken by the authors).

References Alphei, J., Bonkowski, M., Scheu, S. (1996) Protozoa, Nematoda and Lumbricidae in the rhizosphere of Hordelymus europaeus (Poaceae): faunal interactions, response of microorganisms and effects of plant growth. Oecologia 106, 111–126. Balík, V. (1996) Soil testate amoebae (Protozoa, Rhizopoda) in environs of the Sokolov city (Czech Republic). Sborník Okresního muzea v Mosteˇ, rˇada prˇírodoveˇdná 18; 5–17 (in Czech with English summary). Bauer, F. (1986) Datenanalyse mit SPSS. Springer, Berlin, Heidelberg. Beck, L., Woas, S., Horak, F. (1997) Taxonomische Ebenen als Basis der Bioindikation – Fallbeispiele aus der Gruppe der Oribatiden (Acari). Abhandlungen und Berichte des Naturkundemuseums Görlitz 69, 67–86. Bessel, H., Schrader, S. (1998) Regenwurmzönosen auf Ackerbrachen in Abhängigkeit von der Brachedauer. Zeitschrift für Ökologie und Naturschutz 7, 169–180. Bongers, T., Bongers, M. (1998) Functional diversity in nematodes. Applied Soil Ecology 10, 239–251. Brauckmann, H.-J., Broll, G., Schreiber, K.-F. (1995) Regenwurmzönosen extensiv beweideter Grünlandflächen der Schwäbischen Alb und des Südschwarzwaldes. Mitteilungen der Deutschen Bodenkundlichen Gesellschaft 75, 19–22. Broll, G., Dunger, W., Keplin, B., Topp, W. (eds) (2000) Rekultivierung in Bergbaufolgelandschaften. Bodenorganismen, bodenbiologische Prozesse und Standortentwicklung. Springer, Berlin. Brüning, E. L., Unger, H., Dunger, W. (1965) Untersuchungen zur Frage der biologischen Aktivierung alttertiärer Rohbodenkippen des Braunkohlentagebaues in Abhängigkeit von Bodenmelioration und Rekultivierung. Zeitschrift für Landeskultur 6, 9–38. Crawford, R. L., Edwards, J. S. ( 1986) Ballooning spiders as a component of arthropod fallout on snowfields of Mount Rainier, Washington, U.S.A. Arctic and Alpine Research 18 (4),429–437. Crossley, D. A., Hoglund, M. P. (1962) A litter-bag method for the study of microarthropods inhabiting leaf litter. Ecology 43, 571–573.

268

Wolfram Dunger et al.

Curry, J. P., Cotton, D. C. F. (1983) Earthworms and land reclamation. In: Satchell, J. E. (ed) Earthworm ecology. Chapman & Hall, London, pp. 215–228. Daniel, O. (1991) Leaf-litter consumption and assimilation by juveniles of Lumbricus terrestris L. (Oligochaeta, Lumbricidae) under different environmental conditions. Biology and Fertility of Soils 12, 202–208. Darbyshire, J. F. (ed) (1994) Soil Protozoa. CAB International, Wallingford. Den Boer, P. J. (1981) On the survival of populations in a heterogeneous and variable environment. Oecologia 50, 39–53. Dunger, W. (1964) Die Bedeutung der Bodenfauna für die Streuzersetzung. Tagungsberichte der Deutschen Akademie der Landwirtschaftswissenschaften Berlin 1963 60, 99–114. Dunger, W. (1968) Die Entwicklung der Bodenfauna auf rekultivierten Kippen und Halden des Braunkohlentagebaues. Ein Beitrag zur pedozoologischen Standortsdiagnose. Abhandlungen und Berichte des Naturkundemuseums Görlitz 43, 1–256. Dunger, W. (1969) Fragen der natürlichen und experimentellen Besiedlung kulturfeindlicher Böden durch Lumbriciden. Pedobiologia 9, 146–151. Dunger, W. (1979) Bodenzoologische Untersuchungen an rekultivierten Kippböden der Niederlausitz. Abhandlungen und Berichte des Naturkundemuseums Görlitz 52, 1–19. Dunger, W. (1987) Zur Einwirkung von Kahlschlag, Grundwasserabsenkung und forstlicher Rekultivierung auf die Boden-Makrofauna, insbesondere Regenwürmer. Abhandlungen und Berichte des Naturkundemuseums Görlitz 60, 53–60. Dunger, W. (1989) The return of the soil fauna to coal mined areas in the German Democratic Republic. In: Majer, J.D. (ed) Animals in primary succession. The role of fauna in reclaimed lands. Cambridge University Press, New York, pp. 307–337. Dunger, W. (1991a) Zur Primärsukzession humiphager Tiergruppen auf Bergbauflächen. Zoologische Jahrbücher (Systematik) 118, 423–447. Dunger, W. (1991b) Wiederbesiedlung der Bergbaufolgelandschaft durch Bodentiere. Abhandlungen der Sächsischen Akademie der Wissenschaften zu Leipzig, Mathematisch-naturwissenschaftliche Klasse 57, 51–61. Dunger, W. (1997a) Bodenbiologische Forschung zur Rekultivierung ostdeutscher Braunkohlenhalden. Mitteilungen der Deutschen Bodenkundlichen Gesellschaft 83, 141–144. Dunger, W. (ed) (1997b) Untersuchungen zur Fauna 35jähriger aschemeliorierter Kippböden. Mit Kiefer und Roteiche/Linde aufgeforstete Standorte im Revier Domsdorf-Tröbitz (Niederlausitz). DFG-Innovationskolleg. Abschlussbericht der Arbeitsgruppe Görlitz unter Mitarbeit von B. Balkenhol, H. Boyle, A. Christian, K. Schmidtfrerick, H.-J. Schulz, T. Schwalbe, B. Seifert, H. Stöhr, J. Vogel, K. Voigtländer und M. Wanner. Dunger, W. (1998a) Ergebnisse langjähriger Untersuchungen zur faunistischen Besiedlung von Kippböden. In: Pflug, W. (ed) Braunkohlentagebau und Rekultivierung. Springer, Berlin, pp. 625–634. Dunger, W. (1998b) Immigration, Ansiedlung und Primärsukzession der Bodenfauna auf jungen Kippböden. In: Pflug, W. (ed) Braunkohlentagebau und Rekultivierung. Springer, Berlin, pp. 635–644. Dunger, W., Fiedler, H. J. (eds) (1997) Methoden der Bodenbiologie. Gustav Fischer, Jena. Dunger, W., Schulz, H.-J., Zimdars, B. (subm.) Colonisation behaviour of collembola under different conditions of dispersal. Pedobiologia. Dunger, W., Voigtländer, K. (1990) Succession of Myriapoda in primary colonization of reclaimed land. In: Minelli, A.: Proceedings of the 7th international congress of Myriapodology. E. J. Brill, Leiden, New York, København, Köln, pp. 219–227. Dunger, W., Wanner, M. (1999a) Ansiedlung und Primärsukzession der Bodenfauna auf Tagebaukippen – Ergebnisse und theoretische Ansätze. Verhandlungen der Gesellschaft für Ökologie 29, 201–211.

Soil fauna at mine sites

269

Dunger, W., Wanner, M. (eds) (1999b) Immigration und Sukzession ausgewählter Gruppen der Bodenfauna in terrestrischen Kippökosystemen und Bergbaurandflächen. Schlussbericht des BMBF Projektes Nr. 0339668, Görlitz. Dunger, W., Wanner, M., Xylander, W. (eds) Primary succession of soil fauna. A long-term study in mine sites of Eastern Germany. Naturwissenschaftliche Publikationen des Staatlichen Museums für Naturkunde Görlitz (in prep.). Dworschak, U. R. (1997) Earthworm populations in a reclaimed lignite open-cast mine of the Rhineland. European Journal of Soil Biology 33, 75–81. Eisenbeis, G. (1994) Die biologische Aktivität von Böden aus zoologischer Sicht. Braunschweiger Naturkundliche Schriften 4, 653–658. Eisenbeis, G. (1998) Die Untersuchung der biologischen Aktivität von Böden. II. Der Minicontainer-Test. Praxis der Naturwissenschaften Biologie 4/47, 22–29. Felinks, B., Hahn, B., Wiegleb, G. (1999) Vegetationstypen der terrestrischen Bereiche in der Niederlausitzer Bergbaufolgelandschaft. Archiv für Naturschutz und Landschaftsforschung 38, 43–84. Foissner, W. (1987) Soil protozoa: fundamental problems, ecological significance, adaptations in ciliates and testaceans, bioindicators, and guide to the literature. Progress in Protistology 2, 69–212. Freckman, D. W. (1982) Nematodes in soil ecosystems. University of Texas Press, Austin. Gange, A. C., Brown, V. K. (1997) Multitrophic interactions in terrestrial systems. Blackwell, Oxford. Glück, E. (1989) Waldbodenverbringung: zoologische Aspekte. Natur und Landschaft 64, 456–458. Goralczyk, K., Verhoeven, R. (1999) Bodengenese als Standortfaktor für Mikrofauna – Ciliaten und Nematoden in Dünenböden. In: Koehler, H., Mathes, K., Breckling, B. (eds) Bodenökologie interdisziplinär. Springer, Berlin, pp. 105–118. Graefe, U. (1993) Die Gliederung von Zersetzergesellschaften für die standortsökologische Ansprache. Mitteilungen der Deutschen Bodenkundlichen Gesellschaft 69, 95–98. Graefe, U. (1997) Bodenorganismen als Indikatoren des biologischen Bodenzustands. Mitteilungen der Deutschen Bodenkundlichen Gesellschaft 85, 687–690. Hauser, H., Kowarsch, N. (1998) Boden- und standortkundliche Beschreibung der Untersuchungsflächen des Projektes „Immigration und Sukzession ausgewählter Gruppen der Bodenfauna in terrestrischen Kippökosystemen und Bergbaurandflächen“. Manuscript Staatliches Museum Görlitz, 74 pp. Heublein, D. (1983) Räumliche Verteilung, Biotoppräferenzen und kleinräumige Wanderungen der epigäischen Spinnenfauna eines Wald-Wiesen-Ökotons. Ein Beitrag zum Thema Randeffekt. Zoologische Jahrbücher (Systematik) 110, 473–519. Higgs, E. S. (1997) What is good ecological restoration? Conservation Biology 11, 338–348. Hildmann, E., Wünsche, M. (1996) Lignite mining and its after-effects on the Central German landscape. In: Hüttl, R. F., Heinkele, T., Wisniewski, J. (eds) Minesite recultivation. Kluwer Academic Publishers, Dordrecht, pp. 79–87. Hohberg, K. Soil nematode fauna of afforested mine sites (in prep.). Höser, N. (1994) Verteilung der Regenwürmer am Hang und in der Aue: Abhängigkeit von Bodenschichtungsvorgängen. Zoologische Jahrbücher (Systematik) 121, 335 – 357. Hüttl, R. F., Heinkele, T., Wisniewski, J. (eds) (1996) Minesite recultivation. International Symposium, Germany, 6–8 June 1994. Kluwer Academic Publishers, Dordrecht/Boston/ London. Hüttl, R .F., Klem, D., Weber, E. (1999) Rekultivierung von Bergbaufolgelandschaften. Das Beispiel des Lausitzer Braunkohlereviers. Walter de Gruyter, Berlin, New York. Jochimsen, M. E .A. (1996) Reclamation on colliery mine spoils founded on natural succession. In: Hüttl, R. F., Heinkele, T., Wisniewski, J. (eds) Minesite recultivation. Kluwer Academic Publishers, Dordrecht, pp 99–108.

270

Wolfram Dunger et al.

Keplin, B. (1999) Abbau und Mikroarthropoden-Besiedlung von Kiefern-Wurzelstreu (Pinus nigra und Pinus sylvestris) im Minicontainer-Test auf rekultivierten Forststandorten. Braunschweiger naturkundliche Schriften 5, 913–924. Keplin, B., Dageförde, A., Düker, C. (1999) Untersuchungen zum Abbau von organischer Substanz und zur Bodenbiozönose auf forstlich rekultivierten Kippstandorten. In: Hüttl, R. F., Klem, D., Weber, E. (eds) Rekultivierung von Bergbaufolgelandschaften. Walter de Gruyter, Berlin, New York, pp. 73–87. Keplin, B., Hüttl, R. F. (1999) Decomposition of needle litter in Pinus sylvestris L. and Pinus nigra Arnold stands on carboniferous substrates in the Lusatian lignite mining district. In: Tajovsky´, K., Pizˇl, V. (eds) Soil Zoology in Central Europe. ISB AS CR, Cˇeské Budeˇjovice, pp. 129–135. Klausnitzer, U. (1993) Untersuchungen zur primären Immigration und Sukzession von Arthropoden in Kippmaterial des Braunkohlenbergbaues, vorwiegend untersucht in Espenhain. Diplomarbeit Univ. Leipzig, 71 S. Kobel-Lamparski, A., Lamparski, F. (1999) Oberboden als Lebensraum der Streu- und Bodenfauna. In: Dunger, W., Wanner, M. (eds) Immigration und Sukzession ausgewählter Gruppen der Bodenfauna in terrestrischen Kippökosystemen und Bergbaurandflächen. Schlussbericht BMBF-Förderprojekt Nr. 0339668, Görlitz, pp. 407–423. Langkamp, P. J., Dalling, M. J., Calder, D. M., Farrell, T. P. (1979) Studies on the rehabilitation of mined areas on Groote Eylandt, Northern Territory. Reclamation Review 2, 147–155. Larink, O., Kratz, W. (1994) Köderstreifen-Workshop in Braunschweig – ein Resümee. Braunschweiger naturkundliche Schriften 4, 647–651. Majer, J. D. (ed) (1989) Animals in primary succession. The role of fauna in reclaimed lands. Cambridge University Press, New York. Meisterfeld, R. (1997) Thekamöben – ihr Potential für Ökosystemforschung und Bioindikation. Abhandlungen und Berichte des Naturkundemuseums Görlitz 69, 87–95. Ogden, C. G. (1983) Observations on the systematics of the genus Difflugia in Britain (Rhizopoda, Protozoa). Bulletin of the British Museum (Natural History) Zoology 44, 1–73. Pflug, W. (ed) (1998) Braunkohlentagebau und Rekultivierung. Springer, Berlin. Römbke, J., Dreher, P. (eds) (1999) Bodenbiologische Bodengüte-Klassen. Abschlussbericht im Auftrag des Umweltbundesamtes. Berlin, 276 pp. Rushton, S. P. (1986) Development of earthworm populations on pasture land reclaimed from open-cast coal mining. Pedobiologia 29, 27–32. Sachs, L. (1999) Angewandte Statistik: Anwendung statistischer Methoden.Springer, Berlin, Heidelberg. Scheu, S. (1992) Changes in the lumbricid coenosis during secondary succession from a wheat field to a beachwood on limestone. Soil Biology and Biochemistry 24, 1641–1646. Scheu, S., Parkinson, D. (1994) Effects of earthworms on nutrient dynamics, carbon turnover and microorganisms in soils from cool temperate forests of the Canadian Rocky Mountains – laboratory studies. Applied Soil Ecology 1, 113–125. Scheu, S., Theenhaus, A., Jones, T. H. (1999) Links between the detritivore and the herbivore system: effects of earthworms and collembola on plant growth and aphid development. Oecologia 119, 541–551. Scullion, J., Malik, A. (2000) Earthworm activity affecting organic matter, aggregation and microbial activity in soils restored after opencast mining for coal. Soil Biology & Biochemistry 32, 119–126. Standen, V., Stead, G. B., Dunning, A. (1982) Lumbricid populations in open cast reclamation sites and colliery spoil heaps in County Durham, U.K. Pedobiologia 24, 57–64. Tiunov, A. V., Scheu, S. (1999) Microbial respiration, biomass, biovolume and nutrient status in burrow walls of Lumbricus terrestris L. (Lumbricidae). Soil Biology & Biochemistry 31, 2039–2048.

Soil fauna at mine sites

271

Topp, W., Gemesi, O., Grüning, C., Tasch, P., Zhou, H.-Z. (1992) Forstliche Rekultivierung mit Altwaldboden im Rheinischen Braunkohlenrevier. Die Sukzession der Bodenfauna. Zoologische Jahrbücher (Systematik) 119, 505–533. Topp, W., Simon, M., Kautz, G., Dworschak, U., Nicolini, F., Prückner, S. (in press) The soil fauna of a reclaimed lignite open-caste mine of the Rhineland: Improvement of soil quality. Ecological Engineering. Törne, E. von (1990) Assessing feeding activities of soil-living animals. I. Bait-lamina-tests. Pedobiologia 34, 89–101. Törne, E. von (1997) Schätzung von Freßaktivitäten. In: Dunger, W., Fiedler, H. J. (eds) Methoden der Bodenbiologie. Fischer, Jena, pp. 373–379. Vogel, J., Dunger, W. (1991) Carabiden und Staphyliniden als Besiedler rekultivierter TagebauHalden in Ostdeutschland. Abhandlungen und Berichte des Naturkundemuseums Görlitz 65, 1–31. Wanner, M., Dunger, W. (1999) Immigration and primary succession of protists (testate amoebae) on recultivated lignite mine spoils in Eastern Germany. Verhandlungen der Gesellschaft für Ökologie 29, 321–327. Wanner, M., Dunger, W. (2001) Biological activity of soils from reclaimed opencast coal mining areas in Upper Lusatia using testate amoebae (protists) as indicators. Ecological Engineering 17/2–3, 323–330. Wanner, M., Dunger, W. (subm.) Primary immigration and succession of soil organisms on reclaimed opencast coal mining areas in eastern Germany. European Journal of Soil Biology. Wanner, M., Dunger, W., Schulz, H.-J., Voigtländer, K. (1998). Primary immigration of soil organisms on coal mined areas in Eastern Germany. In: Pizˇl, V. and Tajovsky´, K. (eds) Soil zoological problems in Central Europe. Cˇeské Budeˇjovice, pp. 267–275. Wanner, M., Hauser, H., Zimdars, B., Dunger, W. (1999) Einwanderung der Bodenfauna auf Kippen des Tagebaues Berzdorf. Berichte der Naturforschenden Gesellschaft der Oberlausitz 7/8, 101–104. Wermbter, N. (2000) Bodenbiologische Eigenschaften von Kippböden im Leipziger und Lausitzer Braunkohlenrevier in Abhängigkeit von Substrat, Nutzung, Bodenbearbeitung und Alter. Dissertation Universität Trier. Westernacher-Dotzler, A., Dumbeck, G. (1992) Vorkommen von Regenwürmern in landwirtschaftlich rekultivierten Flächen in der Niederrheinischen Bucht. Journal of Agronomy & Crop Science 169, 298–309. Wiegleb, G., Bröring, U., Mrzljak, J., Schulz, F. (2000) Naturschutz in Bergbaufolgelandschaften. Landschaftsanalyse und Leitbildentwicklung. Physica-Verlag, Heidelberg. Wolf, G. (ed) (1985) Primäre Sukzession auf kiesig-sandigen Rohböden im Rheinischen Braunkohlenrevier. Schriftenreihe für Vegetationskunde 16, 1–203.