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1

Towards a general species-time-area-sampling effort relationship

Ulrich W., Zalewski M., Hajdamowicz I., Stańska M., Ciurzycki W., Tykarski P.

Polish Journal of Ecology

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2013

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Vol. 61, nr 2

197--205

EN

Species – area (SAR) and species time (STR) relationships describe the increase of species richness with study area and study time and have received much attention among ecologists and are used in different branches of biodiversity research. Unknown sample size effects often hinder a direct comparison of SAR and STR shapes of different taxa and regions. Further, space and time interact during the accumulation of species due to the common sample universe. Here we develop a simple power function scaling model of species richness that integrates space, time, sample size and their interactions. We show that this model is able to precisely describe average species densities and the increase of species richness in a regional metacommunity of a large sample of spiders on Mazurian lake islands (Northern Poland). The model predicts strong area – sample size and time – sample size interactions. Judged from the SAR (z = 0.08) and STR (y = 0.64) slopes it points to only moderate spatial β–diversities but high local temporal species turnover. We suspect that the parameters of many published SARs are strongly influenced by unknown sampling time and sample size effects that make direct comparison difficult.

2

Can periodically drained ponds have any potential for terrestrial arthropods conservation? - a pilot survey of spiders

Tropek R.

Polish Journal of Ecology

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2012

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Vol. 60, nr 3

635-639

EN

Periodical summer drying has been a common practice in fishponds management in many intensively used European landscapes. It was shown that these ephemeral biotopes are often colonised by endangered plant communities typical for riverine gravel beds. However, almost nothing is known about their conservation potential for terrestrial arthropods. Spiders at a periodically drained bottom of the Manovicky rybnik pond, western Czech Republic, were surveyed from May to September 2007 by pitfall-trapping, vegetation sweeping and individual collecting. Although just 25 spider species were found, several of them are considered as regionally important. Psammophilous Steatoda albomaculata (nationally nearly threatened) and xerothermophilous Tricca lutetiana are regionally very rare species occurring mainly in warmer areas; the Manovicky rybnik pond is only their second known locality in the study region. Hypsosinga heri and H. pygmaea, two recorded hygrophilous species, are regionally very rare species of colder, near-natural wetlands. The combination of several other hygrophilous and xerothermophilous species, caused by habitat diversity of extreme substrate conditions, forms the spider community at the site. Co-occurrence of these species and abiotic conditions was typical for periodically disturbed riverine gravel beds, an almost vanished habitat in Central Europe. The relatively broad habitat relations diversity of the species inhabiting this very small (1.5 ha) site and the occurrence of several regionally important species indicate that periodically drained pond bottoms could be important anthropogenic habitats for terrestrial arthropods conservation.

3

Central European habitats inhabited by spiders with disjunctive distributions

Ruzicka V.

Polish Journal of Ecology

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2011

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Vol. 59, nr 2

367-380

EN

The purpose of the study is to find which habitats within Central Europe support the persistence of isolated populations of spider species of both boreal and Alpine origins. Twenty-five species exhibited disjunctive distributions with their main sub-area in the tundra or boreal forest, and isolated sub-areas in the temperate zone of Central Europe. Six species exhibited disjunctive distributions with their main sub-area in the Alps, and isolated sub-areas in the temperate zone in Central Europe. Only (approximately) one-third of the species of boreal origin have the same habitat, as in the boreal zone. Twothirds of the species inhabit different habitats, or have narrowed their ecological valency. Screes play an important role in the survival of these isolated populations of species of boreal origin in the temperate zone, together with mountain summits, mountain forests, and peat bogs. Extensive complexes of sandstone rocks also enables the survival of isolated populations of species of boreal origin.

4

Variation and diversity of spider assemblages along a thermal gradient in scree slopes and adjacent cliffs

Ruzicka V., Zacharda M.

Polish Journal of Ecology

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2010

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Vol. 58, nr 2

361-369

EN

The thermal regime of a phonolite scree slope on Klic Mt., North Bohemia, Czech Republic, was monitored by miniature data loggers. The spiders were collected throughout the entire scree field area and on the adjacent cliff. In 2005 and 2006, the mean internal temperatures at the lower margins of the scree slope were 0.1 and 0.5[degrees]C, whereas the mean external ambient temperatures were 6.8 and 7.2[degrees]C, respectively. The difference, therefore, is 6.7[degrees]C. The long-term cooling of the basal portions, along with the winter heating of the central and upper parts of the scree, are the most specific microclimatic phenomena. The boreomontane species inhabit the extremely cold vents at the lower margins of the scree slope. Species of alpine origin inhabit the middle portions of the scree slope. Six thermophilous species inhabit the sun-exposed rock margins of Klic Mt., which is nearly at the uppermost limit of their vertical distribution in the Czech Republic.

5

Effects of forested strips on spider assemblages in adjacent cereal fields: dispersal activity of spiders

Kajak A.

Polish Journal of Ecology

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2007

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Vol. 55, nr 4

691-704

EN

Spiders are important components of agricultural ecosystems as far as they affect markedly the abundance of crop pests. The objective of the study was to determine whether the planting of forested strips (shelterbelts) in agricultural area enhances the biomass of spiders active on soil surface of cereal fields and if the exchange of individuals between these habitats depends on the age of trees. The investigations were carried on in 2000 and repeated in 2003/2004 along transects across young shelterbelts (2 -11 years old) - ecotones - fields. In the second period the 150 years old forest strip was included into the study. So altogether in both periods the study was performed in the strip-managed area in forested strips 2, 6, 7, 11, and 150 years old, adjacent cereal fields and in the control field located in a deforested area. The intensity of patrolling (number of individuals captured per trap per day) the soil surface by spiders was investigated using pitfall traps forming lines parallel to the shelterbelt. The results of both investigation periods show, that forested strips increased the biomass of patrolling spiders (BP - biomass of spiders per trap per day) in the fields. It was higher in the fields located in the strip-managed area than in the deforested area by ca 70%. The BP decreased gradually with the increasing distance from the strips. Differences between the strip and the field at a distance of 50 m were significant (two-way ANOVA, post hoc Turkey test). The reason for the higher BP in the fields adjacent to forested strips was mainly the dispersal of large spiders from strips to adjacent fields. Dispersal is high between the very young strip and the field and low between the oldest strip and the field. The group of forest inhabiting species accounted for 0.3-0.5% of the total number of spiders in the field located in deforested area. In the fields adjacent to young shelterbelts this proportion increases with the strips age from 1 to 6%. But in the field bordering the oldest forest strip it is low again and accounted for 1.4%. In this field the proportion of agrobionts is almost as high (94%) as in the field located in deforested area (98%). Similarly the species diversity was very low. The mean individual body mass of spiders from all the fields located in the strip-managed area was 2.7 times higher than in the control field (P<0.001). It can be concluded, that in the old forest strips the number of species, which don.t disperse to surrounding, increases. This conclusion may be important for landscape management.