Arachnologische Mitteilungen 35

spider fauna of semi-dry grasslands 57 S CHIKORA &S ACHER 1998,M USTER 1999, B UCHAR & R UZICKA 2002). Most of the spiders seem to be habitat generalists that extend into all types of habitats of the study area. In contrast to this, the number of species which are stenotopic to sand habitats is noticeably low. Thus expected species like Agroeca lusatica , Arctosa perita , Sit- ticus saltator and Steatoda albomaculata , as recorded by L ADEMANN (1995) on dry grasslands of north-western Ger- many, or Clubiona frutetorum , Pellenes tripunctatus and Sitticus distinguendus , found by F INCH (1997) in similar habitats, are missing. The absence of Arctosa perita is especially surprising, because this species usually occurs in all types of sandy habitats (B RAUN 1969, B AUCHHENSS 1990, 1995, L EIST 1994, M ERKENS 2002, S CHNITTER et al. 2003). Probably this fact can be explained by the low number and size of patches with open sand and sparse vegetation in the study area. According to M ERKENS (2002) the Atlantic cli- mate seems to accelerate the succession of inland dunes and to reduce the ex- treme character of the habitat. Several common species of other habitat types can be found regularly in dunes or dry grassland while in the east of Germany these species stay in their ‘typical’ habi- tats, probably because the eastern sandy sites are drier and hotter than those in the west. The largest number of specimens could be caught at sites D2 and D3 which can be explained by the very fre- quent occurrence of the lycosid spiders Pardosa monticola and Pardosa palustris . As mentioned above, Pardosa palustris is able to cope with a wide spectrum of ecological conditions and a high level of disturbance. Pardosa monticola is common and frequent in grassland fragments, often inhabiting short dune grasslands (B ONTE & M AELFAIT 2001, B ONTE et al. 2003, K REUELS & B UCHHOLZ 2006). Both species show high locomotory activity and Fig. 2 : Principal Component Analysis of spider communities from the military training area of Dorbaum – species plot (eigenvalue first axis = 0.714, second axis = 0.222; cumulative percentage variance of species data first axis = 71.4, second axis = 93.6). D1 – D7 = sites, A, A/B, B, C = species groups. Abbreviated species names: Alo_acc = Alopecosa accentuata , Alo_cun = Alopecosa cuneata , Alo_pul = Alopecosa pulverulenta , Ara_hum = Arae- oncus humilis , Bat_gra = Bathyphantes gracilis , Cen_con = Centromerita concinna , Cer_pro = Cercidia prominens , Cne_obs = Cnephalocotes obscurus , Dic_nig = Dicymbium nigrum , Drs_pub = Drassodes pubescens , Dra_lut = Drassyllus lutetianus , Dra_pus = Drassyllus pusillus , Eno_tho = Enoplognatha thoracica , Eri_atr = Erigone atra , Eri_den = Erigone dentipalpis , Gon_viv = Gongylidiellum vivum , Hah_nav = Hahnia nava , Hah_ono = Hahnia ononidum , Hap_sig = Haplodrassus signifer , Hyp_pyg = Hypsosinga pygmaea , Man_aca = Mangora acalypha , Mas_sun = Maso sundevalli , Mei_rur = Meioneta rurestris , Mic_her = Micrargus herbigradus , Mil_pus = Microlinyphia pusilla , Pac_deg = Pachygnatha degeeri , Par_agr = Pardosa agrestis , Par_hor = Pardosa hortensis , Par_lug = Pardosa lugubris , Par_mon = Pardosa monticola , Par_pal = Pardosa palustris , Par_pra = Pardosa prativaga , Par_pul = Pardosa pullata , Pel_par = Pelecopsis parallela , Phl_fas = Phlegra fasciata , Phr_fes = Phrurolithus festivus , Pis_mir = Pisaura mirabilis , Rob_liv = Robertus lividus , Ste_pha = Steatoda phalerata , Stm_lin = Stemonyphantes lineatus ,Tap_pra = Tapinocyba praecox ,Ten_ten = Tenuiphantes tenuis ,Tis_vag = Tiso vagans ,Tro_rur = Trochosa ruricola ,Tro_ter = Trochosa terricola ,Wal_ant = Walckenaeria antica , Wal_dys = Walckenaeria dysderoides , Xer_min = Xerolycosa miniata , Xys_ace = Xysticus acerbus , Xys_cri = Xysticus cristatus , Xys_koc = Xysticus kochi , Zel_ele = Zelotes electus , Zel_lat = Zelotes latreillei , Zel_pet = Zelotes petrensis . For species representation values see Tab. 4.