장음표시 사용
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adventage of canonical corresponde iace is that it Sllows us, with only one graph. thebellavio ur of the communi ty in ternas of the factors measti red: it also allows us to est abiisti associations os species having similar bellavi our with the total group offactors, for ex ample C. lubricia and V hiammoniS Or P. Pygmaeum, A. aculeiam and A. nitidum Fig. l) OUTEIRO et a l. l 993) Theres ore the two techni ques are complementary and the use of the two together will provide information on both the communi ty as a whole and on each individual species. Direct comparison of our resulis with those of related previous studies is difficult, part ly because the Studi ed species occur in a wide range of communi tytypes, and partly because a number of relevant edaphic factors sparticularly texture factors) have received very litile attention to date. The only previ ous study that simultaneo us ly used CCA and ecological prosiles analysis is that of OUTEIRO et til. l 993). These authors likewise obtained similar results with the two techni ques,
Fix. I. Plot os species and factor weightings on the titi st two axes extracted by canonical correspon
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and concluded that soli texture and litter pH are ille most important edaphic factors affecting the distribution of terrestriat gastropolis. The resulis of the present studyindicate that, in addition to these three factors, humidi ty, C. N Ca and Mg contentare also important. ONDINA et a L sl 995), in a stud y abo ut relationships of terrestriat gastropods and soli factors, comment that the factors that explain beller species distribution are: moisture, Ca, M g. Al and factors related with the soli texture. Although the resulis of CCA Fig. l) indicate iliat V. contriacm doesia 't showclear preferences for any factor probably iis distribution may be affected by the soli factors load ing heavi ly on axes I and II but in a bimodal or multimodat fashion not revealed by the ordination) while ecological profites Fig. 2) suggesis that this
The ordination of the other ni ne species, according to their preferences forhigh or low values of a factor, are similar in both analysis. Ecological profites and CCA show similar resulis for C. lubrica and Ν. hammonis spreference for solis with high values of carbon, nitrogeia, moisture, and clay). C. lubrica is considered
P. Pygmaeum i S considered by severat authors as a species tolerant to ac id
of coarse texture and with high nitrogen and calciun values. we have mund these species in solis with high values of gravet content, it suggesis that the limited ca-
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Fix. 2. Ecological prosiles sor those sactors to whicli ut least one species silowed a significantly non-unis orna distribulion. Class intervals and sactor codes are listud in table II. Species codes arctisted in the Figure 2. Prosile values os i indicate unis orna distribution: values greator than i indicale presereiace. ' p Q 0.05 p Q 0.00l dissercnces with respect to unis orna prosile).
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IMPORTANCE OF EDAPHIC FACTORS ON THE DISTRIBUTION OF TERRESTRIAL GAsTRopoos 2 3
paci ty of displacement of the se species is hel ped for coarse sand texture. In this kind of solis, the smaller si Zed species can burrow easter in Order to lay eggs Or to
V. Pulchellia is a common species of moist places, typical of meadows MEIERl98J. CAMERON l9J8).We mund concordance in the resulis of both analysis: this species appears in solis with high values of pH, magnesium and calcium. OUTEIRO l 988) found T. PuSilla, principally, in mea lows with high calcium values and medium-high pH of litter values 5.6-8.9), besides our resulis stlow that this species
The faci that A. intermedius and V. pellucida were plotted clo se to the originos the lo species CCA ordination Fig. l) indicates that their distribution is affected by edaphic factors, which were not recorded or whicli do not load heavi ly on axes Iand II. But these species don't show preferences with respect to any factors considered in ecological profites suggesting that the distribution of A. intermedius and V. pellucida with in the study area may be genu inely independent of soli factors considered here. We have mund A. intermedius and V. pellucida in almost ali sana ples. This is in accordance with previ ous reporis of the se species' very wide habitat
In conclussion the two techni ques used here are complementary and the use of the two together will provide information on both the communi ty as a whole andon each individual species. On the other hand. the resulis refer exclusi Vely to the Stud y area, as the intervals of the factor values may change in other locations
thereby affecting the species different ly.
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Actia Mologica Academiae Scientiarum Hungiaricae 46 δ); ρρ. 275-290. 2000
EDGE EFFECT ON WEEVIL AND SPIDER COMMUNITIES ATTHE BUΚΚ NATIONAL PARK IN HUNGARY
Recent ly, there is an increas ing interest in studying transitionat areas like
ecotones). Ecotone is a transition Zone belween plant associations. It may Vary in nature and structure frona abrupi discontinuities to broad and genti e gradients depending on the scale of observation. In a land scape iis most striking and eas ity recognis able fornas are the forest edges whicli occur as contact Zones between forest standS and treetes s areas. FOrest edges are a type of ecotones, whicli are interpretedon the meso- spatiat scale and on the communi ty levet HOLLAND et al. l99l MURCIA l 995). Nowadays. forest edges are in the focus os both ecological re-SearcheS and consei Vation purpOses, hecause progressive destruction and fragmentation os habitat s have led to the in creas ing number of forest edges S AVNDER Set a L l99 l), whereas in other areas they have dis appeared due to recent plantationsor abandonment of adjacent agri cultural areas. The ecological relationships that exist at the contact os different habitats forna the elige effeci hypothesis. This hy-
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pothesis states that species richness increases at the borders bet ween different hab
MUONA l 98 ). However, studies examining edge effect on animais functioning ondifferent trophic leve is are very important in order to explore whether forest edges have the fame effect On them. In the present paper we analysed the edge effect On two invertebrate taxo nomic group, whicli operate at different trophic leve is, howeVer there is trophic relation belween them. we studi ed the weevit communities Coleoptera: Curculio no idea), as a phytophagoUS group, and Spider communitieS Araneae), as a predator groti P.
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est. Earlier the clear-cut area was ploughed. But it has not been culti valed for i5 years. Frequent herbaceolis species are the fame as the ones mentioned aliove, at the forest edge. The area of the mea lowis approximately l0 ha. In the herbaceous layer frona May to September three-weekly sweep-net Samples were takensrom the forest interior, the forest elige. and frona the meadow along a transect running perpendiculario the forest edge. At each habitat the samples were taken in an area covered l0κl0 meter. Each Sample consisted of 50 sweeps. The distance of the sweeping area os the forest interior and the me adowwcre at least 50-J0 meter fro in the forest edge. Sampling took place during the late moria ing hours institi, dry weather. The samples were taken in the Same sweeping area os cach habitat during the stud yyear, theres ore pooled Samples were used for the numerical analysis.
TO test edge essect on weevit and spider communities the species richness frona the three habitats were compared with each other. The sample si Ze of both the weevit and the spider assemblages dissered in the three studi ed habitats. To correct the effect of the different Sample sire in comparing Species richness, we estimated the number Os species in subsamples of P0 individuals stoin cach habitat using ES m) diversi ty. The si Ze of the subsamples is recommended to be the 8 90R of the small- est Sample . In Our study the smallest sample si Ze was 80 individua is, there fore was calculated the ES m) diversi ty for a subsample containing P0 individuat s. ES m) diversi ty is a statisticat method forestimating the number os species expected in a random Subsample drawn hom a larger sample HURI BERT l9Pl. SMITH L GRASSI E l9JP. TOTHMERESZ l99 ). ES m) diversi ty is defined as where ni is an integer and p. is the relative abunda iace of the ι-th species of the communi ty. The resulting value caia be interpreted as a diversi ty index hecause the method take into account both species richness and relative abundances . ES m) diversi ty is an accepted and reli able statisti calmethod study ing species richness of in vertebrate communities with disserent Sample si Ze se. g. Ni EMEI A etat. l 993). ES m) diversi ty was calculated by the Divord program package TOTHMERESZl 993ti). Test os the dissere iaces in the ES m) diversi ty was based On the normal approximations publis hed by TONG l 983). Similari ty of the species composition was calculated by Matus ita similari ty. The similari ty structure was displayed by cluster analysis using the ward-Oi loci susion method. The similari ty was calculated by the NuCOSA program package TOTHMERESZ l 993b).
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number of species in a randona subsample of P0 individual s) of the weeviis communities of forest edge and mea low were not different significantly while the disse ferences between these and the assem blage of the forest interior were significant Huicheson 's t-test, di l 20, pC0. 0 ).
followed by the assemblage of forest interior and the community of mea low Fig. l D). The expected number of species of the community of forest edge was significantly higher than that of the assemblages of forest interior and mea low Huic hesoli s t-test. iis l20. pQ0. 0β) whereas the other differe iace in the ES PO)diversi ty was not significant. Composition of the weevit communities of the forest edge and the mea lowwere similar to each other, and the weevit assemblage of the forest interior differed considerably frona the two above communities Fig. Pa). The cluster analysis showed a different division for the spider data. Composition os the spider communi ty of forest elige were more similar to the assemblage of forest interior than to the communi ty of the meadow Fig. 2b).
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EDGE EFFECT ON WEEVIL AND SPIDER COMMUNITIES AT THE BUM K Np IN HUNGARY 2J9Fig. i. Expected number os species estimated for P0 individuals 1 S. D.) for the weevit and spidercommunities in the three habitais