'Carabidologists do it all' (Niemelä 1996a) is a phrase with which most European carabidologists are familiar. Indeed, during the last half a century, professional and amateur entomologists have ...contributed enormously to our understanding of the basic biology of carabid beetles. The success of the field is in no small part due to regular European Carabidologists' Meetings, which started in 1969 in Wijster, the Netherlands, with the 14th meeting again held in the Netherlands in 2009, celebrating the 40th anniversary of the first meeting and 50 years of long-term research in the Dwingelderveld. This paper offers a subjective summary of some of the major developments in carabidology since the 1960s. Taxonomy of the family Carabidae is now reasonably established, and the application of modern taxonomic tools has brought up several surprises like elsewhere in the animal kingdom. Progress has been made on the ultimate and proximate factors of seasonality and timing of reproduction, which only exceptionally show non-seasonality. Triggers can be linked to evolutionary events and plausibly explained by the "taxon cycle" theory. Fairly little is still known about certain feeding preferences, including granivory and ants, as well as unique life history strategies, such as ectoparasitism and predation on higher taxa. The study of carabids has been instrumental in developing metapopulation theory (even if it was termed differently). Dispersal is one of the areas intensively studied, and results show an intricate interaction between walking and flying as the major mechanisms. The ecological study of carabids is still hampered by some unresolved questions about sampling and data evaluation. It is recognised that knowledge is uneven, especially concerning larvae and species in tropical areas. By their abundance and wide distribution, carabid beetles can be useful in population studies, bioindication, conservation biology and landscape ecology. Indeed, 40 years of carabidological research have provided so much data and insights, that among insects - and arguably most other terrestrial organisms - carabid beetles are one of the most worthwhile model groups for biological studies.
Memories of Terry Erwin Spence, John; Kavanaugh, David; Maddison, David R ...
ZooKeys,
06/2021, Letnik:
1044, Številka:
3
Journal Article
Recenzirano
Odprti dostop
We were fortunate to have known Terry not only as an excellent professional coleopterist and an enthusiastic colleague, but also as a good friend. Entomological meetings for us came with an evening ...supper or two with Terry and the kind of laid-back personal catch-up that happens only among friends with long-term interest in each other’s lives. Through our connections with the University of Alberta and George Ball we were also happy members of Terry’s basal academic family. While we will join the rest of a broader scientific community in missing his presence in development of ideas about beetles, biodiversity and evolution, the kinds of work that Terry promoted will continue. We will, of course, be interested in following how the understanding of carabids and nature develops further from Terry’s contributions. This will most certainly continue to grow, partly through the efforts of those that he has influenced. Every practicing research scientist has some role to play in the great chain of discovery, and much of this volume is meant to celebrate Terry’s contributions and showcase how they have influenced the work of others.
Our own more enduring sense of loss will flow from the personal interactions with Terry that were generally part of our timelines. Despite the sadness associated with such loss, our memories of interactions with Terry underscore a sense of joy and gratefulness for having connected with him interpersonally in life. Given Terry’s affable and social nature, many others will have such memories. Thus, when Lyubomir Penev asked us to coordinate a selection of ‘memories’ for this memorial volume, we were happy to undertake the task and gather together a selection of memories of our friend, Terry Erwin. What follows is a series of recollections by people who knew and worked with him from a number of perspectives during a broad range of his academic career.
We are most grateful to those who have been willing to share their reflections. These are presented here as a way of reaching beyond Terry’s considerable scientific influence to also preserve some sense of his influence on the lives of people, and the ways in which he encouraged and inspired them. We thank all the contributors for their efforts and Diane Hollingdale for work to bring the included photographs to the best possible publication standard.
John R. Spence
Edmonton, Alberta
David H. Kavanaugh
San Francisco, California
David R. Maddison
Corvallis, Oregon
Lowland heathlands dominated by Calluna vulgaris are a characteristic ecosystem of the sandy soils of Northwestern Europe. Many of these heathlands have been converted to agricultural lands in the 20
...th
century, but because increasing recognition of their nature conservation value has led to an increase in restoration efforts. Since about 2005, several experiments were carried out in a number of former agricultural areas in the Netherlands with the aim of accelerating the succession in vegetation and surface-dwelling fauna towards heathland. We discuss two projects in which the monitoring of the beetle fauna using pitfall traps was carried out.
In the new reserve “Reijerscamp”, situated in the Central Netherlands, a 10-year monitoring project was carried out in an abandoned sandy field area of ca 200 ha from 2006-2015. The area consisted of a former grain field and a grass seed nursery, with small wooded areas here and there and the aim is to enlarge the area of dry heathland. In 2006, at four 5-10 ha locations, a few hundred meters apart, the nutrient-rich topsoil layer was removed, and the Pleistocene sand exposed. On a part of each of these sites, heather cuttings were deposited to accelerate the formation of dry heathland. The study consisted of five sampling years spread over the entire study period. In each sampling year, 15-25 series of 5 pitfalls were used to sample the reserve during the period April – October, on the untreated, former agricultural parts and on the four parts with removed top soil, both on the bare sand and on the parts with heather deposition. The results for ground beetles, did not support the hypothesis in all respects. From the results, it became clear that creating environmental heterogeneity, generally contributes to the ground beetle diversity in the reserve. However, the period of ten years was too short to show a clear indication that the faunal succession is moving towards a heathland fauna. The first years showed an interesting fauna with a lot of stenotopic, rare and unexpected species and the local diversity was very high. Halfway through the investigation period, the number of species as well as the numbers of individuals declined. After ten years, in general the character of the fauna was significantly more eurytopic and many of the rare species occurring in the first years vanished. On the four sites with removed topsoil, the carabid fauna differed significantly from the former agricultural land, but there was only a minor difference in the fauna of the parts with only bare sand and those with deposit of heath cuttings, although a clear heathland vegetation was visible in the parts with deposits. Because the area is surrounded by agricultural land and a large forested area, there is hardly direct connection to heathland that can serve as a source for immigration of characteristic heathland species with low dispersal power.. The succession to a typical heathland fauna in this reserve will therefore probably take probably several decades.
Immediately adjacent to the National park “Dwingelderveld” (in the north of the Netherlands) the “Noorderveld”, consisting of 200 ha of arable field was acquired for nature restoration. Also here, the aim was to convert this area into heathland by removing the nutrient-rich topsoil layer in 2012-2013, to a depth of more than 60 cm, thus creating a seedless sterile substrate, poor in nutrients. After the topsoil removal, a full factorial experiment of pH manipulation and biotic additions at wet and dry sites was set up to accelerate the process of heathland restoration. Each of 27 plots (9 x 9 meters), received either a liming treatment, acidification or neither, in combination with either heathland sods, heath cuttings, or neither, totaling 9 treatment combinations. From 2013 till 2018 the carabid fauna was monitored frequently by pitfall catches in the plot’s centers. In the first years the highest diversity was observed in the plots with lime and sod cuttings and also the most characteristic heathland ground beetle species were found at these plots. Later on, these differences became less significant, which may be due to the relatively small size of the plots, which hardly can be regarded independent of each other. Conclusion is still that adding lime and sods is the best way for heathland restoration, but the differences with the control treatment were small.
The striking result of the present comparison is that the Noorderveld was rather quickly inhabited by characteristic heathland species. This may be due to the fact that latter is directly connected to the vast heathland complex of the national park Dwingelderveld, in contrast to the Reijerscamp, which is isolated from the closest heathlands by a railroad, a highway, large forests and a highly agricultural landscape. connectivity therefore seems to be a crucial condition for characteristic species to colonize new territory, especially for species with low dispersal powers.
This book presents the story of Dutch ground beetles and illustrates the contribution of pitfall trapping to our understanding of the ecology of this fascinating and unusually well-studied group of ...beetles.
Aim: Current climate, biotic habitat provision and historical events are known drivers of diversity patterns. However, these three factors are seldom evaluated together. Here, we study the influence ...of climate, the distribution of deciduous forests and Pleistocene climate changes on the species diversity of Carabus ground beetles in Europe. Location: Continental Europe. Methods: We used geographically weighted regressions (GWR) to explore geographical variation in the relationship between species richness and current climate in a spatially explicit context. Further, we analysed simultaneously the network of relationships among current temperature, climatic variability since the Last Glacial Maximum (LGM) and the distribution of deciduous forests through structural equation models (SEM). Also, we assessed dissimilarity in the composition of European faunas by means of beta diversity metrics related with true spatial replacement and nestedness. Results: We find that Carabus richness patterns are, at least in part, influenced by water-energy dynamics. However, the effects of current climate are also shaped by Pleistocene glaciations, as water and energy variables change in importance at the southern limits of the ice sheet during the LGM. Accordingly, this border results in abrupt shifts in the relative importance of both (1) current and past climate correlates on Carabus richness, and (2) nestedness and true turnover on the compositional changes among their assemblages. Moreover, we also detect a direct effect of the geographical distribution of deciduous forests on Carabus species richness in both northern and southern regions. Main conclusions: Our results confirm that the processes shaping diversity patterns may depend on the history of particular regions. While Carabus richness seems to be largely driven by current climate in southern Europe, in the north it appears to be more affected by the imprint of past climates. Our findings also suggest that the areas of influence of Pleistocene glaciations may depend on the idiosyncratic characteristics of particular taxa.
Conservation management is expected to increase local biodiversity, but uniform management may lead to biotic homogenization and diversity losses at the regional scale. We evaluated the effects of ...renewed grazing and cutting management carried out across a whole region, on the diversity of plants and seven arthropod groups. Changes in occurrence over 17 years of intensive calcareous grassland management were analysed at the species level, which gave insight into the exact species contributing to regional homogenization or differentiation. Reponses were compared between species differing in habitat affinity, dispersal ability, food specialisation and trophic level. Local species richness increased over the sampling period for true bugs and millipedes, while carabid beetles and weevils declined in local species richness. Species richness remained unchanged for plants, woodlice, ants and spiders. Regional diversity and compositional variation generally followed local patterns. Diversity shifts were only to a limited extent explained by species’ habitat affinity, dispersal ability, trophic level and food specialisation. We conclude that implementation of relatively uniform conservation management across a region did not lead to uniform changes in local species composition. This is an encouraging result for conservation managers, as it shows that there is not necessarily a conflict of interest between local and regional conservation goals. Our study also demonstrates that shifts in diversity patterns differ markedly between taxonomic groups. Single traits provide only limited understanding of these differences. This highlights the need for a wide taxonomic scope when evaluating conservation management and demonstrates the need to understand the mechanisms underlying occurrence shifts.
In the face of ongoing habitat fragmentation, species-area relationships (SARs) have gained renewed interest and are increasingly used to set conservation priorities. An important question is how ...large habitat areas need to be to optimize biodiversity conservation. The relationship between area and species richness is explained by colonization-extinction dynamics, whereby smaller sites harbor smaller populations, which are more prone to extinction than the larger populations sustained by larger sites. These colonization-extinction dynamics are predicted to vary with trophic rank, habitat affinity, and dispersal ability of the species. However, empirical evidence for the effect of these species characteristics on SARs remains inconclusive.
In this study we used carabid beetle data from 58 calcareous grassland sites to investigate how calcareous grassland area affects species richness and activity density for species differing in trophic rank, habitat affinity, and dispersal ability. In addition, we investigated how SARs are affected by the availability of additional calcareous grassland in the surrounding landscape.
Beetle species richness and activity density increased with calcareous grassland area for zoophagous species that are specialists for dry grasslands and, to a lesser extent, for zoophagous habitat generalists. Phytophagous species and zoophagous forest and wet-grassland specialists were not affected by calcareous grassland area. The dependence of species on large single sites increased with decreasing dispersal ability for species already vulnerable to calcareous grassland area. Additional calcareous grassland in the landscape had a positive effect on local species richness of both dry-grassland specialists and generalists, but this effect was restricted to a few hundred meters.
Our results demonstrate that SARs are affected by trophic rank, habitat affinity, and dispersal ability. These species characteristics do not operate independently, but should be viewed in concert. In addition, species' responses depend on the landscape context. Our study suggests that the impact of habitat area on trophic interactions may be larger than previously anticipated. In small habitat fragments surrounded by a hostile matrix, food chains may be strongly disrupted. This highlights the need to conserve continuous calcareous grassland patches of at least several hectares in size.
Experiments were conducted between 2001 and 2003 in constructed plant communities that were set up in 1996 on abandoned agricultural land. The primary aim of the experiment was to study how different ...secondary vegetation succession scenarios influence community development of invertebrates in different trophic levels. The succession scenarios were obtained by sowing high diversity or low diversity seed mixtures of mid-successional plant species in 1996 in comparison with unsown plots where agriculture ceased in 1996 or 1999. Carnivorous carabid species generally preferred plots characterized by open vegetation, whereas herbivorous carabids generally favored plots associated with high plant diversity. However, carabid community composition was affected most by sampling year and there was also a dramatic shift over the three years in the relative proportion of the different trophic groups. Irrespective of treatment, the proportion of carnivores in the community declined with time, whereas phytophages increased over the course of the three years. By contrast, the proportion of omnivores peaked during the second year. These long-term changes were, at least to some extent, related to short-term changes in the structure and composition of the plant communities. The importance of local variation and temporal changes in plant species richness on carabids and other insect fauna are discussed.
PDF
