Arthropod Abundance Research Articles

Jumping Performance and Behavior of the Globular Springtail Dicyrtomina minuta.

Springtails are among the most abundant arthropods on earth and they exhibit unique latch-mediated spring-actuated jumping behaviors and anatomical systems. Despite this, springtail jumps have not been well described, especially for those with a globular body plan. Here, we provide a complete description and visualization of jumping in the globular springtail Dicyrtomina minuta. A furca-powered jump results in an average take-off velocity of 1 ms-1 in 1.7 ms, with a fastest acceleration to liftoff of 1938 ms-2. All jumps involve rapid backwards body rotation throughout, rotating on average at 282.2 Hz with a peak rate of 368.7 Hz. Despite body lengths of 1-2 mm, jumping resulted in a backwards trajectory traveling up to 102 mm in horizontal distance and 62 mm in vertical. Escape jumps in response to posterior stimulation did not elicit forward-facing jumps, suggesting that D. minuta is incapable of directing a jump off a flat surface within the 90° heading directly in front of them. Finally, two landing strategies were observed: collophore-anchoring, which allows for an immediate arrest and recovery, and uncontrolled landings where the springtail chaotically tumbles. In comparison to other fast jumping arthropods, linear performance measures globular springtail jumps place them between other systems like fleas and froghoppers. However, in angular body rotation, globular springtails like D. minuta surpass all other animal systems. Given the extraordinary performance measures, unique behavioral responses, and understudied nature of these species, globular springtails present promising opportunities for further description and comparison.

Variation in ground-dwelling arthropod communities across differently managed infiltration basins

Abstract As urbanisation continues to increase, terrestrial arthropod diversity declines. Urban green spaces represent unique opportunities to preserve arthropod diversity in urban environments. We quantify how ground-dwelling arthropod communities vary both seasonally and across three differently maintained stormwater infiltration basins in Ellisville, Missouri, United States of America. One basin was routinely mowed, a second was mowed only seasonally, and a third was intentionally planted to attract pollinators and was not mowed during this study. We expected higher plant diversity to correlate with higher arthropod diversity. Therefore, we expected the unmowed basin to have the highest levels of arthropod diversity and abundance and the mowed basin to have the lowest. Four collection periods spanned spring, early summer, late summer, and fall. During each collection period, five pitfall traps were placed throughout each basin for 48 hours. In total, 5686 specimens were collected and identified, representing 59 families. Arthropod communities did not vary across basins or collection dates, largely contrasting with existing literature. The results of this study do not indicate that different mowing regiments in infiltration basins will affect the ground-dwelling arthropod communities at a family level, although the effect on species-level diversity remains to be investigated.

Weather influenced nestling growth of an insectivorous but not a granivorous grassland passerine in Argentina

Nestling growth of birds can be affected by weather fluctuations. In general, it is expected that higher temperatures favor growth by improving food availability and nestling metabolism, while rain hinders it by reducing foraging efficiency. However, most of these patterns have been described in insectivorous cavity-nesting birds in temperate forests. We tested these predictions in two neotropical grassland ground-nesting birds with contrasting nestling diets and therefore potentially different responses to weather. We measured nestlings of the Hellmayr's Pipit (Anthus hellmayri, an insectivorous passerine) and the Grassland Yellow-Finch (Sicalis luteola, which feeds its nestlings exclusively with seeds) during three breeding seasons (2017–2020) in central-eastern Argentina. We took measurements of tarsus and body mass, modeled growth curves using nonlinear mixed-effects models, and evaluated the effects of minimum daily temperature and precipitation during the growth period and the 30 days prior to hatching. For pipits (60 nestlings from 21 nests), minimum temperatures during the growth period were positively associated with tarsus and body mass asymptotes. Also, there was a positive association between precipitation during the pre-hatching period and tarsus asymptote. Conversely, none of the weather variables analyzed had significant effects on nestling growth of finches (131 nestlings from 35 nests). Dietary contrast between species may explain the different results. Arthropod activity and abundance can be affected by weather variations within the span of a breeding season, whereas seeds may depend on conditions from previous years, making the effects harder to detect. Fledglings with reduced asymptotic size can have reduced chances of survival. Hence, pipit populations could be impacted if they experience cold and dry conditions during their breeding season, which is of major relevance in the current context of climate change.

Arthropods Diversity in Insectary Plant on Cocoa Cultivation Ecosystems

The purpose of this research to determine the population abundance and arthropod diversity on insectary plants that are among the cocoa plantation ecosystems. The research was conducted on five types of insectary plants which were used as objects for observing arthropods, that is; H.annuus L., T.erecta L., Z.elegans Jaqc., G.globose L. and C.argentea. Arthropod observations were carried out using three methods the results of which were identified and then the Shannon-Wiener species diversity index (H'). The results showed that the total abundance of arthropods in the five types of insectary plants was 374 individuals with the highest total arthropods being found in T.erecta with 118 individuals, followed by H.annuus 79 individuals, C.argentea purple 70 individuals, Z.elegans 55 individuals, and the lowest in 52 individual G.globose. The number of arthropods found was 98 individuals acting as pollinators, 111 individuals predators, 53 individuals decomposers, 9 individuals parasitoids, 96 individuals pests and 7 individuals as neutral insects from 10 orders, 34 families and 51 species. The species diversity index (H') value for all types of insectary plants is included in the moderate category with a value of 1.0 <H'> 3.322 which means sufficient productivity, balanced ecosystem conditions and moderate ecological pressure.

Microarthropod as soil quality indicator for ravenous soils of North-West Bundelkhand region

In this study microarthropod population was compared with established soil quality index (SQI), so that indicator potential of soil microarthropods could be established. Forty-three georeferenced sites based on advanced techniques were selected from the major representative land uses viz., arable land, forest, grazing land and degraded land that fall under four administrative districts viz., Datia, Jalaun, Hamirpur and Tikamgarh. The samples were analysed for soil physical, chemical, and biological parameters. The soil quality index (SQI) was computed using minimum data set derived through principal component analysis and based on expert opinion. Soil organic carbon, microbial biomass carbon, nitrogen, potassium, and clay content were selected as contributors of soil quality index. Regression between SQI and micro arthropod abundance established a definite relationship, establishing that the soil micro arthropods might be used as soil quality index for monitoring soil quality for this geography.

Assessing whether peri-urban agricultural land or plantation forest is a better green infrastructure for ground arthropods at local and landscape scales

City agencies across multiple continents have invested millions of funds in ambitious afforestation projects in urban and peri-urban areas to enhance the city green infrastructure. One example is the Beijing One Million Mu Plain Afforestation Project, which has established 146,000 ha of plantation forests, mainly on arable lands. This contradicts the national arable land conserving policies and has dramatically changed local habitat types and landscape context. However, the impact of these processes on biodiversity is not well understood. To investigate this impact at local and landscape scales, we explored a space-for-time approach. We selected 12 plantation forests and their nearby arable lands along a gradient of plantation forest cover in the surrounding landscapes. We surveyed ground spiders and carabids and analyzed their responses to local habitat type, landscape context, and their interaction. In the sampled landscapes, plantation forest cover increased (12.0%–35.9%), while arable land cover decreased (58.3%–31.8%). 96.3% of the new plantation forests were established on arable lands. Intensive afforestation on arable lands did not increase local ground arthropod diversity. In fact, ground arthropod abundance and species richness in plantation forests were significantly lower than in arable lands when the surrounding arable land cover was relatively high. With surrounding arable land cover decreasing, ground arthropod abundance and species richness in plantation forests increased but did not exceed those in nearby arable lands. Hence, the overall ground arthropod diversity at landscape scale was not improved. These findings suggest that, from a biodiversity conservation perspective, plantation forests did not surpass peri-urban agricultural lands as a better green infrastructure . However, ground arthropods benefit from rich local non-crop herb communities. Conserving peri-urban agricultural lands and implementing extensive management regimes for agricultural lands and existing plantation forests are more effective tools than ambitious afforestation of agricultural land in peri-urban areas of Beijing and other metropolises.

Coverings on Pitfall Traps Influence the Abundance of Ground-Dwelling Arthropods

Pitfall traps provide a cost-effective method of studying the diversity and abundance of ground-dwelling arthropods, such as beetles and spiders. Their efficiency depends on factors such as size, shape, and substances used to kill or preserve the specimens. Entomologists often employ covers on pitfall traps to prevent dilution of fixation liquids or keep the traps open. In this study, we investigated whether the presence or absence of covers, as well as their colour (black versus translucent), over pitfall traps has an impact on the species diversity and abundance of carabid beetles and harvestmen. These arthropods serve as common examples of ground-dwelling invertebrates, both in forest and meadow environments. Our findings revealed that traps with black-coloured coverings captured significantly higher numbers of beetles than translucent traps, but the uncovered traps were not significantly different from the two. The species richness tended to be highest in uncovered traps. The uncovered traps were the most efficient in capturing adult harvestmen, followed by translucent and black covers in terms of adult harvestmen abundance and diversity. In conclusion, the use of covers on pitfall traps significantly affects the estimates of arthropod abundance and should be taken into account in future research.

Sown Covers Enhance the Diversity and Abundance of Ground-Dwelling Predators in Mediterranean Pear Orchards

Intensive agriculture has a strong impact on the structure of arthropod communities in soil. Sown covers can contribute to their conservation, especially for generalist predators such as spiders and predatory beetles. The aim of this research was to assess the effect of cover crop management on the abundance and diversity of ground-dwelling arthropods. For this purpose, a three-year experiment was conducted in a pear orchard that was divided into three blocks with two plots each: one with a sown cover of mixed plants from different families, including Boraginaceae, Asteraceae, Apiaceae, Brassicaceae, and Fabaceae, and the other with no cover, in which any spontaneous plants were periodically removed without using herbicides. The abundance of ground-dwelling arthropods was sampled using pitfall traps. The sown cover increased the overall richness of arthropods. Additionally, spiders from the families Lycosidae and Linyphiidae, as well as beetles from the families Carabidae and Staphylinidae, were more abundant in the sown cover. Conversely, detritivores such as collembolans and beetles from the family Tenebrionidae were less abundant in the cover. The abundance of ants was not affected by the type of cover. The sown cover increased the diversity of arthropods in the crop, as well as the abundance of generalist predators.

Key environmental factors underlying terrestrial arthropod abundance and diversity in alley-cropping and monoculture oil palm plantations

Key environmental factors underlying terrestrial arthropod abundance and diversity in alley-cropping and monoculture oil palm plantations

The influence of distance from crushed stone mining on surface-active arthropods and soil properties

ABSTRACT Background: Mining of crushed stone for use in construction is among the various anthropogenic activities in the Eastern Cape province in South Africa that alter natural landscapes. However, little is known about the impact of these activities on arthropods and soil chemical properties. Objectives: We investigated the effect of distance (5, 30, 50 and 70 metres) from the mining sites on species richness, abundance and composition of surface-active arthropods, as well as composition and concentration of soil chemical properties (soil pH, calcium, magnesium, phosphorus and zinc). Methods: The study was conducted at two mining sites in Nyandeni Local Municipality within the O.R. Tambo District Municipality that were commissioned in 2014. Arthropods were sampled using pitfall traps and thereafter sorted into morphospecies, while an auger was used to collect soil samples. Permutational multivariate analysis was used to compare the composition of the arthropods and soil chemical properties among distances from the mining activities, while arthropod species richness and abundance, as well as concentrations of soil chemical properties, were analysed using the one-way analysis of variance or Kruskal-Wallis test. Results: Arthropod species richness, abundance and composition were not influenced by distance from mining activities. Although among soil chemical properties, mining activities altered the concentration of zinc only, we found dissimilarities in soil composition between the sampling point at the edge of the mining activities and sampling points that were away from the mining sites. Conclusion: We found no evidence of the impact of crushed stone mining on surface-active arthropods; however, our study revealed a negative impact of crushed stone mining on soil chemical properties.

Ephedra shrubs facilitate local arthropod communities in the Andean Puna: Implications for conservation and habitat restoration

In high-altitude deserts, the vegetation is spatially structured as a mosaic of patches with vegetation and interpatches of bare soil. Shrub patches create microhabitats that facilitate the persistence of other organisms by ameliorating climate extremes and increasing soil nutrients and moisture. Although this facilitative effect has been studied mainly on shrub understorey plants, the positive influence of desert shrubs may extend to the local arthropod community. In this study, we examined the hypothesis that plant facilitation by the desert shrub species Ephedra multiflora and E. breana positively influences the epigeal arthropod communities of the Andean Puna. We found that arthropod abundance, richness and diversity were all higher on Ephedra shrub microsites relative to paired open microsites. The harsh environmental conditions prevailing in the Puna ecosystems and the protection and resources provided by plants could jointly explain the positive influence of Ephedra shrubs over the arthropod community. The growth of tourism and the boom for lithium, as well as the increasing drought expected for the region under climate change scenarios, strengthens the importance of conserving shrub cover in these ecosystems to sustain biodiversity and ecosystem functioning. Our results are also relevant for restoration projects that consider the whole biological community, where using Ephedra as foundation shrubs to support desert endemics could be a strategy for land restoration.

Soil arthropod communities collected from agricultural soils influence wheat growth and modify phytohormone responses to aboveground herbivory in a microcosm experiment

Soil arthropods can affect plant growth and aboveground interactions directly via root herbivory and indirectly through nutrient cycling and interactions with soil microorganisms. Research on these effects of soil arthropods has focused on a few taxa within natural systems, largely neglecting agroecosystems and arthropod community-level effects. This study investigated the effects of soil arthropod communities from cereal-based agroecosystems on wheat plant growth and above-belowground interactions. Nutrient cycling and wheat growth were measured in a greenhouse microcosm experiment using field-collected agricultural soils from two rotational schemes with and without their soil arthropod communities. The effects of soil arthropods on aboveground phytohormones and colony growth of an aphid [Metopolophium festucae cerealium (Stroyan)] infesting the plants were measured. Wheat grown in soils with arthropod communities had significantly greater root (+ Arth mean: 0.15 ± 0.01 g; − Arth mean: 0.06 ± 0.01 g; F1,54 = 72.34, p < 0.001) and shoot biomass (+ Arth mean: 0.39 ± 0.03 g; − Arth mean: 0.24 ± 0.03 g; F1,54 = 17.61, p < 0.001), greater soil nitrate concentrations (+ Arth mean: 62.18 ± 4.76 mg NO3− - N kg−1 soil; − Arth mean: 13.06 ± 0.61 mg NO3− - N kg−1 soil; F1,54 = 99.89, p < 0.001), and altered root architecture compared to controls. Soil arthropod communities collected from the two rotational schemes differed significantly in abundance and diversity, but affected wheat growth similarly. Aphid colony growth (+ Arth mean: 30.50 ± 4.06; − Arth mean: 22.13 ± 3.36; χ21,27 = 21.19, p < 0.001), but not plant damage by aphids (+ Arth mean: 2.72 ± 0.17, − Arth mean: 2.69 ± 0.16; F1,27 = 0.02, p > 0.05), was significantly greater on wheat grown in soils with arthropods. Aphids, in turn, modified the effects of soil arthropods on root architecture and increased the abundance of soil arthropods. Wheat grown in soils with arthropods had increased levels of stress- and defense-related phytohormones in response to aphid herbivory, while phytohormones of wheat plants grown in soils without arthropods did not differ with aphid presence. Soil arthropod communities may help plants defend against herbivores aboveground by facilitating phytohormone induction while offsetting costs by increasing soil nutrients and modifying plant growth. By using taxonomically diverse field-collected soil arthropod communities from agroecosystems, this study showed that community-level effects on plant growth are more complex and dynamic than the effects of any single taxon, such as Collembola, illustrating that interactions within communities can produce emergent properties that alter the net effect of soil arthropods on plant growth. The results indicate that community-level effects of soil organisms should be considered as part of sustainable plant production and protection strategies.

Prey choice in insectivorous steppe passerines: New insights from DNA metabarcoding

Food availability plays a key role affecting almost every aspect of bird ecology, including bird population, distribution, reproduction, and behavior. Understanding the functional relationship between prey availability and insectivorous birds’ diet is important in the current scenario of habitat loss and declining of insect and bird populations. We used a fecal metabarcoding approach coupled with prey availability sampling (arthropod abundance and biomass) to test for evidence of selective foraging in a shrub-steppe passerine assemblage over the 2017–2019 breeding seasons in semi-natural steppes of central Spain. The results showed that the six bird species selected specific arthropod taxa. Heteroptera, Orthoptera, Araneae, Lepidoptera and some Coleoptera families were the main selected prey taxa, while Formicidae appeared to be avoided, suggesting that shrub-steppe passerines tend to select prey items providing essential nutrients and energy during the breeding season, while poor quality ones are neglected. Our findings highlight the utility of metabarcoding dietary data to assess prey selection patterns in insectivorous passerines and provide valuable information for the development of conservation and management programs to ensure the long-term availability of crucial food resources for shrub-steppe birds and other insectivores.

Abundance and Diversity of Leaf Litter and Subsoil Arthropods in Four Different Sites of Three Agroecological Zones of Northwest Part of Bangladesh

Leaf litter and subsoil arthropods are biotic factors of an ecosystem that play a significant role in nutrient cycling between soil and vegetation. The present study aimed to explore the abundance and diversity of leaf litter and subsoil arthropods in four different sites of three agroecological zones of the Northwest part of Bangladesh. A total of 1920 individuals belonging to 17 orders, 28 families and 34 species were found in the present study where 1099 individuals (14 orders, 23 families, 28 species) from Rajshahi University Campus (Site A), 259 individuals (6 orders, 7 families, 8 species) from Rajshahi Fruit Research Center (Site B), 354 individuals (7orders, 13 families, 13 species) from Kakon Hat Municipality (Site C) and 208 individuals (5 orders, 10 families, 10 species) from Chalan Beel (Site D) were collected during the period from November 2021 to October 2022. In this study, within the three agroecological zones, the highest number of individuals was recorded in Site A (n=1099, 57.24%) and the lowest number in Site D (n=208, 10.83%). Among 17 orders Coleoptera (624, 32.50%) was the first dominant order, Hymenoptera (414, 21.56%) was the second largest order, followed by Araneae (202, 10.52%) and the least dominant order was Metastigmata (8, 0.42%). Formicidae was the most dominant family among collected 28 families, sharing 376 individuals of the total captured individuals and Staphylinidae, sharing 198 individuals, was the second largest family, whereas Tenebrionidae (n=8), Psychodidae (n=8), and Laelapidae (n=8) were the minor dominant families in this study. Among the total of 34 species, Lasioderma sp. was the most dominant species, sharing 189 individuals with 9.84% of the total collected individuals whereas Alphitobius sp., Psychoda sp., and Hypoaspis sp. were least dominant species, and each species of these three comprised of only 8 members. In this study, 15 species were very common, 5 were common, 7 were fairly common, and 7 were rare. The values of Shannon diversity index (H'), Simpson’s diversity index (I-D), Margalef diversity index (DMg), Menhinick Richness index (DMn), Berger Parker dominance index (d) and Pielou’s evenness index (J') were 3.22, 0.95, 4.37, 0.78, 0.10, respectively. The study was the first attempt to examine the abundance and diversity of leaf litter and subsoil arthropods in four different sites of three agroecological zones in the northwest part of Bangladesh. Further study may be necessary for molecular identification of these species.

Metabarcoding dietary analysis in the insectivorous bat Nyctalusleisleri and implications for conservation.

In this study, we aim to uncover diet preferences for the insectivorous bat Nyctalusleisleri (Leisler's bat, the lesser noctule) and to provide recommendations for conservation of the species, based on the analysis of prey source habitats. Using a novel guano trap, we sampled bat faeces at selected roosts in a forest in Germany and tested two mitochondrial markers (COI and 16S) and three primer pairs for the metabarcoding of bat faecal pellets. We found a total of 17 arthropod prey orders comprising 358 species in N.leisleri guano. The most diverse orders were Lepidoptera (126 species), Diptera (86 species) and Coleoptera (48 species), followed by Hemiptera (28 species), Trichoptera (16 species), Neuroptera (15 species) and Ephemeroptera (10 species), with Lepidoptera species dominating in spring and Diptera in summer. Based on the ecological requirements of the most abundant arthropod species found in the bat guano, we propose some recommendations for the conservation of N.leisleri that are relevant for other insectivorous bat species.

Impacts of habitat connectivity on grassland arthropod metacommunity structure: A field-based experimental test of theory.

Metacommunity theory has advanced scientific understanding of how species interactions and spatial processes influence patterns of biodiversity and community structure across landscapes. While the central tenets of metacommunity theory have been promoted as pivotal considerations for conservation management, few field experiments have tested the validity of metacommunity predictions. Here, we tested one key prediction of metacommunity theory-that decreasing habitat connectivity should erode metacommunity structure by hindering species movement between patches. For 2 years, we manipulated an experimental old-field grassland ecosystem via mowing to represent four levels of habitat connectivity: (1) open control, (2) full connectivity, (3) partial connectivity, and (4) no connectivity. Within each treatment plot (10 × 10 m, n = 4 replicates), we measured the abundance and diversity (i.e., alpha and beta) of both flying and ground arthropods using sticky and pitfall traps, respectively. We found that the abundance and diversity of highly mobile flying arthropods were unaffected by habitat connectivity, whereas less mobile ground arthropods were highly impacted. The mean total abundance of ground arthropods was 2.5× and 2× higher in the control and partially connected plots compared to isolated patches, respectively. We also reveal that habitat connectivity affected the trophic interactions of ground arthropods, with predators (e.g., wolf spiders, ground spiders) being highly positively correlated with micro-detritivores (springtails, mites) but not macro-detritivores (millipedes, isopods) as habitat connectivity increased. Together these findings indicate that changes in habitat connectivity can alter the metacommunity structure for less mobile organisms such as ground arthropods. Because of their essential roles in terrestrial ecosystem functioning and services, we recommend that conservationists, restoration practitioners, and land managers include principles of habitat connectivity for ground arthropods when designing biodiversity management programs.

Arthropods Abundance and Diversity in Federal University Wukari’s Farm, Taraba State, Nigeria

Despite the fact that Federal University Wukari's farm has a huge area covered in grasses and trees, nothing is known about the variety, number, and species of the arthropods that live there. The purpose of this study was to evaluate the species richness, variety, and the abundance of arthropods present at the Federal University Wukari School farm. From September to November 2021, a total of 1698 unique arthropods were gathered, 32 species, 29 families, and 18 orders. Each month had an average of 618 to 550 arthropods, representing 27 to 30 different species. The fauna was dominated by Order Hymenoptera, which had 1110 individuals from 6 species. With a rating of 5.106, September was the month with the most abundant and varied arthropods.

Differential effects of soil conservation practices on arthropods and crop yields

AbstractMany agricultural management tactics, such as reduced tillage, aim to promote biodiversity and ecosystem services. Responses to such tactics can be context dependent, however, and differentially impact (i) functional groups of service‐providing organisms and (ii) crop yields. In canola (Brassica napus L., B. rapa L.) crop fields, we assessed how soil tillage and landscape context (amount of semi‐natural habitat within 1 km of each field) affected arthropod biodiversity and crop yield. We assessed effects of full (multiple tillage passes that leave soil surface bare), intermediate (tilled once and some stubble remains), or no (seed planted directly into last year's stubble) tillage on functional groups with unique diets and reproductive strategies: (i) herbivores, (ii) kleptoparasites, (iii) parasitoids, (iv) pollinators, and (v) predators. Effects of tillage and landscape context on arthropod abundance and diversity varied across functional groups. Pollinators responded strongest to tillage, benefitting from intermediate tillage. Predators and herbivores responded strongly to landscape context, as both were more abundant in landscapes with more semi‐natural habitat. Our results suggest that natural history differences among functional groups mediate effects of landscape context on biodiversity. However, variation in arthropod communities had little effect on canola crop yield. The effects of soil management practices on aboveground arthropods are complex, and practices thought to increase some aspects of agricultural sustainability may not be beneficial in other contexts. Identifying practices such as intermediate tillage that may increase soil quality and arthropod diversity is a key to designing agricultural ecosystems that will effectively benefit both biodiversity and human well‐being.

Inverted Soil Mounding as a Restoration Approach of Seismic Lines in Boreal Peatlands: Implications on Plant and Arthropod Abundance and Diversity

In northern Alberta, Canada, much of treed boreal peatlands are fragmented by seismic lines—linear disturbances where trees and shrubs are cleared for the exploration of fossil fuel reserves. Seismic lines have been shown to have slow tree regeneration, likely due to the loss of microtopography during the creation of seismic lines. Inverted soil mounding is one of the treatments commonly applied in Alberta to restore seismic lines and mitigate the use of these corridors by wildlife and humans. We assessed the effects of mounding on understory plants and arthropod assemblages three years after treatment application. We sampled five mounded and five untreated seismic lines and their adjacent treed fens (reference fens). Compared to reference fens, mounded seismic lines showed on average lower bryophyte (6.5% vs. 98.1%) and total understory cover (47.2% vs. 149.8%), ground-dwelling spider abundance (226.0 vs. 383 individuals), richness (87.2 vs. 106.4 species) and diversity (19.0 vs. 24.6 species), rove beetle abundance (35.2 vs. 84.8 individuals), and ant richness (9.0 vs. 12.9 species). In contrast, rove beetle and ground beetle richness (39.0 and 14.5 species, respectively) and diversity (16.8 and 7.8 species, respectively) were higher on mounded seismic lines compared to reference fens (richness: 18.0 and 7.5 species, respectively; diversity: 7.0 and 3.8 species, respectively). This is one of the first studies to assess arthropod responses to restoration efforts in the context of oil and gas disturbances in North America, and our results highlight the need to incorporate multiple taxa when examining the impact of such treatments.

A Middle Permian Oasis for Vertebrate and Invertebrate Life in a High-Energy Fluvial Palaeoecosystem of Southern Gondwana (Karoo, Republic of South Africa)

The Gansfontein palaeosurface (Fraserburg, Karoo, South Africa), which is correlated with the stratigraphic lowermost part of the continental Middle–Upper Permian Teekloof Formation, is revisited. This treasure trove of peculiar and exquisitely preserved sedimentary structures and invertebrate and vertebrate traces serves as a document of a set of fluvial paleoenvironments ranging from small ponds to marginal lacustrine and muddy riverine outer banks. It represents an isolated and relatively small “oasis” within the dominating sedimentary environments of the Teekloof Formation characterized by fine and medium-grained siliciclastics related to repeated higher-energy flooding events. The vertebrate traces include abundant therapsid trackways and, locally, tetrapod swimming traces. Tetrapod footprints show a very variable preservation in different areas of the palaeosurface, and it also changed based on the time of impression. Fish trails (Undichna) are relatively common. The invertebrate ichnofauna is comprised of abundant arthropod traces and horizontal burrows; however, the palaeosurface was not intersected by intense bioturbation. The occurrence of this scenario of abundant life reflects complex interaction among different tracemakers with the substrate and is evidence of a relatively quiet palaeoenvironment, which was suddenly submerged and sealed during a flooding event. Sedimentological and ichnological insights from such a palaeosurface, therefore, opens a rare window into Middle Permian ecosystems in southernmost Gondwana.