Co-occurrence pattern of ground beetle (Coleoptera, Carabidae) assemblages along pollution gradient in scotch pine forest

Over the last 30 years there has been a great deal of interest in investigating patterns of species co-occurrence across space and time, which may be shaped by interspecific competition for shared resources. A good model of co-occurrence mechanisms is developed among predatory animals along a pollution gradient, where shared resources become more limited in more contaminated areas and the energy budget for detoxification is much higher. Community disassembly by heavy metal pollution may occur when the presence of toxic elements shifts patterns of species co-occurrence from structured to random. On the other hand, limited resources on a pollution gradient should lead to higher competition between dominant species. Disassembly may entail the loss of existing co-evolved interactions among species, which has ramifications for community dynamics and the quality of the functioning of polluted ecosystems. We expect an assemblage dominated by competitive species interactions to exhibit a significant segregation of taxa, whereas one dominated by mutualistic or syntrophic interactions would exhibit an aggregation of taxa. Responses of Carabidae co-occurrence patterns and changes in body size measures to heavy metal concentrations were investigated in a zinc contamination gradient in a Scots pine forest in the vicinity of Olkusz (southern Poland), at 12 study sites. The zinc concentration in the humus layer varied between 108 mg kg-1 dw to 6150 mg kg-1 dw. We used the C-score index, between all possible species pairs in a matrix. The ground beetle assemblages from the reference sites showed a significant segregation pattern. Community disassembly occurred only among assemblages in heavily polluted sites. The average value of skewness and kurtosis were significantly higher in the highly contaminated sites, indicating the greater proportion of small-bodied species in contaminated areas. The Gini coefficient was highest in the low contaminated sites, indicating the body-size inequality of carabid assemblages was greatest in the uncontaminated areas. Our data suggest that increased pollution contributes to the extinction of sensitive forest specialists with large body size and higher competitive abilities, leading to replacement by less sensitive generalists, with smaller body size and that the co-occurrence of species on heavily polluted sites is a result of unstable interactions between species in communities

Assemblages of carabid beetles (Col. Carabidae) and ground-dwelling spiders (Araneae) in natural and artificial regeneration of pine forests

Carabid beetles and spiders are at the top of the hierarchy of general invertebrate predators, which can help to reduce the abundance of harmful forest pests. They are also frequently used as environmental indicators. In this paper we analyzed the abundance, species richness and changes in carabid beetle and spider assemblages in three treatments of pine forest regeneration – natural, natural with soil prepared by ploughing and artificial with seedlings planted in ploughed soil. The most beneficial forest regeneration treatment variant of forest regeneration for carabid beetles and spiders was the natural regeneration of pine stands without any preceding soil preparation. Both taxa responded strongly to soil ploughing. We also noted the replacement of forest species by less sensitive open area species. In carabid assemblages, large changes in the trophic structure were observed, as predatory species were replaced by hemizoophages in the ploughed treatments

Land use and soil characteristics affect soil organisms differently from above-ground assemblages

Background: Land-use is a major driver of changes in biodiversity worldwide, but studies have overwhelmingly focused on above-ground taxa: the effects on soil biodiversity are less well known, despite the importance of soil organisms in ecosystem functioning. We modelled data from a global biodiversity database to compare how the abundance of soil-dwelling and above-ground organisms responded to land use and soil properties. Results: We found that land use affects overall abundance differently in soil and above-ground assemblages. The abundance of soil organisms was markedly lower in cropland and plantation habitats than in primary vegetation and pasture. Soil properties influenced the abundance of soil biota in ways that differed among land uses, suggesting they shape both abundance and its response to land use. Conclusions: Our results caution against assuming models or indicators derived from above-ground data can apply to soil assemblages and highlight the potential value of incorporating soil properties into biodiversity models

Animal occurrence in fragmented forest habitats – important factors at the patch and landscape scale

To date, in research, the main determinants influencing animal assemblages in fragmented forests have been considered to be forest island area and degree of isolation. Such a simplistic approach may have detrimental effects on the obtained results and conclusions, since there are a large number of other factors determining animal persistence in forest islands. In order to identify these factors and evaluate their importance, we reviewed the scientific literature on the topic. In addition to the island area, also patch shape, edge effects and local plant community structure are crucial factors affecting animal assemblages at the forest island scale. At the landscape scale, the total number of forest islands and their combined area, matrix permeability, occurrence of wide ecological corridors as well as isolated trees and woodlands appear to be the most significant factors. Our review further indicates that many of these elements also tend to interact. For instance, edge effects may reduce the area of suitable habitat in a forest patch. Furthermore, some fragmentation effects may be masked by species traits e.g. mobility, food preferences or habitat specialisation. The landscape context also plays a crucial role in animal persistence in fragmented forests. We thus conclude that there is a strong need to investigate the above-mentioned components of habitat fragmentation at the local and landscape scale using appropriate bio-indicators

Zawartosc C organicznego i pH gleb bagiennych i pobagiennych a wystepowanie naziemnych Carabidae w obiekcie Stary Dwor k. Olsztyna

The present study consisted of an evaluation of assemblages of epigeic carabid beetles (Col. Carabidae) colonizing hydrogenic soils (bog and post-bog ones), different in the soil development degree. The observations were conducted on a drained, low bog area called Stary Dwór, which today is used as a cut meadow. This is an oblong depression, filled in with (partly mucky) rush peats and situated in the sandur landscape. It lies in the mesoregion called Pojezierze Olsztyńskie (Olsztyn Lake District) near Olsztyn (UTM DE 65), about 3 km of the southern borders of the town. The field observations for determination of the soil type were conducted using soil catenas. A transect was established, which cut across different types and sub-types of bog and post-bog soils. In this paper, the authors have attempted to answer the question whether the sequence of hydrogenic soils and some parameters chosen to describe them have any influence on assemblages of epigeic carabid beetles dwelling in such habitats. Based on the results, it has been concluded that the soils present in the analyzed peat bog were characterized by the following sequence: muckous soils → peat-muck soils → peat soils. Their properties depended on the position in the soil relief, advancement of muck formation and content of organic carbon. It has been found out that the highest soil ash content in the surface horizons was in muckous soil (90.39%), and the lowest – in profile 3 of peat-muck soil (18.77%). The reaction of the analyzed soils ranged from slightly acidic to neutral and tended to decrease towards the centre of the depression, reaching the lowest value in peat soil. During the two years of our observations, a total of 673 individuals of Carabidae belonging to 29 species were captured. It has been determined that the type of soil as a factor significantly affected the number of captured carabid beetles, but did not influence the species abundance. The decreasing pH gradient as well as an increasing content of organic C were associated with a decreasing number of the species of carabid beeetles tolerant to moisture conditions (mesophilous species), which were being replaced by hygrophilous individuals. As the acidic reaction of soil increased and the soil content of organic matter rose, so did the abundance of mixophagous species at the expense of predatory individuals.W badaniach poddano ocenie zgrupowania epigeicznych biegaczowatych (Col., Carabidae) zasiedlających gleby hydrogeniczne (bagienne i pobagienne) o różnym stopniu rozwoju. Terenem badań było odwodnione torfowisko niskie Stary Dwór, użytkowane jako łąka kośna. Obiekt stanowi podłużne zagłębienie wypełnione torfami szuwarowymi (częściowo zmurszałymi) w krajobrazie sandrowym. Jest on zlokalizowany w mezoregionie Pojezierza Olsztyńskiego, w pobliżu Olsztyna (UTM DE 65), w odległości ok. 3 km od południowych granic miasta. Prace terenowe, w których określano typ gleby, prowadzono metodą katen glebowych. Wyznaczono transekt przebiegający przez różne typy i podtypy gleb bagiennych i pobagiennych. W pracy próbowano uzyskać odpowiedź na pytanie, czy sekwencja gleb hydrogenicznych oraz wybrane parametry opisujące te gleby mają wpływ na zgrupowania zasiedlających je epigeicznych biegaczowatych. Stwierdzono, że opisane na badanym torfowisku gleby charakteryzowały się następującą sekwencją: gleby murszaste → gleby torfowo- murszowe → gleby torfowe. Ich właściwości były uzależnione od usytuowania w reliefie, zaawansowania procesu murszenia oraz zawartości C organicznego. Największą popielność stwierdzono w poziomach powierzchniowych gleby murszastej (90,39%), natomiast najniższą w profilu 3 (18,77%) gleby torfowo-murszowej. Odczyn badanych gleb kształtował się od lekko kwaśnego do obojętnego i malał w kierunku centrum obniżenia, osiągając najniższe wartości w glebie torfowej. W czasie dwuletnich obserwacji na badanym obiekcie odłowiono łącznie 673 osobniki Carabidae należące do 29 gatunków. Stwierdzono, że typ gleby okazał się czynnikiem istotnie wpływającym na liczbę odłowionych osobników Carabidae, natomiast nie wpływał na ich bogactwo gatunkowe. Malejący gradient pH oraz wzrastająca zawartość C organicznego wiązały się ze spadkiem liczebności osobników badanej grupy chrząszczy, mało wrażliwych na zmieniające się warunki wilgotnościowe (mezofile), i zastępowaniem ich przez osobniki wilgociolubne. Wraz ze zwiększającą się kwasowością gleby i zawartością materii organicznej wzrastała również liczebność miksofagów, kosztem zmniejszania się grupy osobników drapieżnych

Beech understoreys in pine forests as places that partly favour the functioning of forest assemblages of ground beetles (Col. Carabidae) in coniferous forest habitats

This study investigates the effect of the enrichment of Scots pine stands with a common beech understorey on changes in the species composition and selected life traits of an important zooindicator group, such as the ground beetles (Col. Carabidae). The field investigations were carried out in a fresh coniferous forest in the Myszyniec Forest District (N Poland) in stands with (P+) and without (P) beech in the understorey. Each treatment was repeated four times. In each repetition, six pitfalls were installed. The traps were replaced 13 times, every two weeks, from April to October. In total, 4412 specimens classified into 25 species of ground beetles were captured. The tree stands with the beech understorey were observed to contain a significantly higher number of species than the ones with the beech undergrowth. Also, the value of the Shannon index of species diversity (H’) and mean individual biomass (MIB) were significantly higher in the treatment with the beech understorey. Principal Component Analysis showed variations in Carabidae assemblages within the analysed types of forest. Pterostichus oblongopunctatus, Pterostichus aethiops and Pterostichus vernalis were more strongly correlated with the stands without beech understorey. The stands enriched with the beech understorey correlated with the occurrence of large zoophages: Carabus arvensis and Cychrus caraboides, and hemizoophages of the genus Amara. An in−depth ecological characterisation of the captured Carabidae showed that the dominant ground beetles in the investigated forest habitats, in terms of the number of caught individuals and species, belonged to forest zoophagous carabids characterised by moderate requirements for moisture in a habitat, and having the spring type of development. Representatives of large zoophages and species with the autumn type of development, i.e. species associated with later ecological succession stages, were more numerously caught in the pine stands without the beech understorey The study provides evidence that justifies the planting of deciduous undergowth in monoculture coniferous pine tree forests. The presence of an understorey contributes to higher: richness of Carabidae species, values of the MIB and abundance of large forest species presenting the autumn type of development, that is the species, which are characteristic for forest areas representing a highly advanced succession stage

Soil management system in hazelnut groves (Corylus sp.) versus the presence of ground beetles (Coleoptera: Carabidae)

Sustaining biodiversity as well as taking advantage of the natural environment’s resistance are the key elements which should be considered when designing integrated plans for the protection of hazelnut groves. An effort has been made in this study to analyse the impact of different soil cultivation methods in hazelnut groves, on the species composition and number of individuals in carabid assemblages (Coleoptera: Carabidae). Another aim was to determine which method of inter-row soil management had the least negative effect on assemblages of these beetles. Because of the type of habitat, the xerothermic species characteristic for southeastern Europe, i.e. Calathus ambiguus, Poecilus lepidus, Harpalus calceatus, and H. griseus, were the most numerous. The qualitative and quantitative analysis of the captured individuals implied that the optimal soil tillage system in young hazelnut groves is when soil is kept fallow with machines or chemicals, or when soil is covered with manure. The least favourable practice for the appearance of ground beetles of the Carabidae family is the use of polypropylene fabric, bark or sawdust, to cover soil

A Modified PitfallTrap for Capturing Ground Beetles (Coleoptera: Carabidae)

Fig. 3. Domination structure of Carabidae captured in two pitfall trap types. A) Traditional pitfall traps, B) Modified pitfall traps.Published as part of <i>Radawiec, Brygida & Aleksandrowicz, Oleg, 2013, A Modified Pitfall Trap for Capturing Ground Beetles (Coleoptera: Carabidae), pp. 473-480 in The Coleopterists Bulletin 67 (4)</i> on page 476, DOI: 10.1649/0010-065x-67.4.473, <a href="http://zenodo.org/record/10104010">http://zenodo.org/record/10104010</a&gt