Arthropod Species Richness Research Articles

Quo vadis Patria Gaucha? Uruguayan pathways of land use change

South American grasslands, socio-ecological systems used heavily for a long time, are currently experiencing dramatic land-use changes due to implementation of large-scale afforestation and agro-industrial cash crops. Applying the conceptual framework of “Multifunctional and sustainable productive landscapes” to Uruguay, we explored the impacts on rural ecosystems and communities based on a long-term monitoring network by assessing species richness of plant and terrestrial arthropods and socio-economic data from national census. We found that silvi- and agricultural industry established mainly at the expense of extensively grazed grasslands and local family farms with traditional techniques, accompanied by a deregulation of the rural labor market, depopulation and aging of rural society. Governmental nature protection efforts increase the native forest cover and establish nature protection areas focusing mainly on forests. We also discuss pathways of land-use change in recent decades and related discourses of local stakeholders.

The Importance of Including Spatial Autocorrelation When Modelling Species Richness in Archipelagos: A Bayesian Approach

One of the aims of island biogeography theory is to explain the number of species in an archipelago. Traditionally, the variables used to explain the species richness on an island are its area and distance to the mainland. However, increasing evidence suggests that accounting for other variables is essential for better estimates. In particular, the distance between islands should play a role in determining species richness. This work uses a Bayesian framework using Gaussian processes to assess whether distance to neighbouring islands (spatial autocorrelation) can better explain arthropod species richness patterns in the Azores Archipelago and in the Canary Islands. This method is flexible and allows the inclusion of other variables, such as maximum altitude above sea level (elevation). The results show that accounting for spatial autocorrelation provides the best results for both archipelagos, but overall, spatial autocorrelation seems to be more important in the Canary archipelago. Similarly, elevation plays a more important role in determining species richness in the Canary Islands. We recommend that spatial autocorrelation should always be considered when modelling an archipelago’s species richness.

Initial herbivory and exposure to herbivory-induced volatiles enhance arthropod species richness by diversifying community assemblages

Plant ecological traits affect the species identity of plant-colonizing arthropods, which in turn induces species-specific trait changes in plants, forming feedback between plants and arthropods. Such feedback can amplify initial differences in species composition, leading to large variations (i.e., high β diversity). We hypothesized that the differences in plant initial conditions have sustained effects on arthropod community composition and species richness. To test this hypothesis, we monitored arthropod community assembly on a willow tree species, Salix eriocarpa, which was experimentally manipulated into three initial treatments: undamaged (in chamber 1); damaged by the specialist leaf beetle, Plagiodera versicolora (chamber 2); and “exposed” plants that were undamaged but were exposed to volatiles from damaged plants (in chamber 2). The arrival and population dynamics of the leaf beetle were affected by the plant’s initial condition (chamber 1 vs. 2), which could result from the microscale environmental heterogeneity between chambers (chamber effect) and/or from the herbivory-related impacts (direct herbivory and exposure to induced volatiles in chamber 2). The community composition on damaged and exposed plants became significantly different on day 32. In addition, the divergence in composition between plant individuals was significantly smaller in undamaged plants (chamber 1) than in damaged and exposed plants (chamber 2) on day 60. The compositional variations (β diversity) between chambers, between treatments, and between days, comprised a large proportion (two third) of the total species richness (γ diversity) in the whole community of arthropods. These results suggest that plant initial condition is a key driver of community assembly and the maintenance of species diversity.

Effect of drip irrigation on richness, abundance and diversity of soil arthropods

Arthropods maintain soil ecosystem in variety of ways like breaking down the plant debris and broadcasting the microorganisms. The human induced changes in the agricultural land (i.e., irrigation methods, tillage practices and land use changes) have profound impacts on the richness, diversity and abundance of arthropods. The present study was carried out to assess the effect of drip irrigation on the richness, abundance and diversity of soil arthropods at three different Tehsils of District Bahawalpur i.e. Bahawalpur, Khairpur and Ahmedpur East. At each location, one flood and one drip irrigated guava orchard was selected. Weekly data of soil arthropods was recorded using 10 pitfall traps (at least 50 feet apart) in each orchard during April and May, 2022. The species richness, abundance, dominance and evenness of soil arthropods were slightly higher in flood irrigation orchards. However, Simpson, Shannon-wiener and chao-1 diversity indices did not vary significantly. Rank abundance curves showed that in all the drip and flood irrigated orchards, there was still some possibility of finding new species with the increasing sample size. Only one ant species Camponotus compressus (Hymenoptera: Formicidae) constituted the major proportion of arthropods abundance in all the orchards whereas most of the species were very low in abundance. The results suggest that the soil arthropod diversity is not significantly affected with the flood and drip irrigation methods. Therefore, keeping in view the proven economic and water conservation advantages, the drip irrigation system can be adopted without harming soil arthropods diversity.

Increased arthropod biomass, abundance and species richness in an agricultural landscape after 32 years

Recent studies reporting widespread declines in arthropod biomass, abundance and species diversity raised wide concerns in research and conservation. However, repeated arthropod surveys over long periods are rare, even though they are key for assessing the causes of the decline and for developing measures to halt the losses. We repeatedly sampled arthropod fauna in a representative Swiss agricultural landscape over 32 years (1987, 1997, 2019). Sampling included eight study sites in four different semi-natural and agricultural habitat types and different trap types (pitfall, window, yellow bucket) over an annual period of 10 weeks to capture flying and ground dwelling arthropod taxa. In total, we analyzed 58,448 individuals from 1343 different species. Mean arthropod biomass, abundance and species richness per trap was significantly higher in 2019 than in the prior years. Also, species diversity of the study area was highest in 2019. Three main factors likely have contributed to the observed positive or at least stable development. First, the implementation of agri-environmental schemes has improved habitat quality since 1993, 6 years after the first sampling. Second, landscape composition remained stable, and pesticide and fertilizer was constant over the study period. Third, climate warming might have favored the immigration and increase of warm adapted species. Our results support the idea that changes in arthropod communities over time is highly context-dependent and complex.Implications for insect conservationWe conclude that the integration and long-term management of ecological compensation patches into a heterogenous agricultural landscape supports insect conservation and can contribute to stable or even increased arthropod abundance, biomass and diversity. Future studies are needed to clarify interdepending effects between agricultural management and climate change on insect communities.

Bt‐maize in neotropical arthropod food webs: community‐stress or lack thereof?

AbstractAlthough the agricultural use of genetically engineered (GE) plants has been employed extensively, its adoption is still controversial and its impact on arthropods has rarely been scrutinized at the community level. If this technology is aimed at a drastic reduction of a key community component, significant community‐level impact is expected and needs to be assessed. Thus, food web analysis was used to assess the short‐term impact of genetically modified maize plants, Zea mays L. (Poaceae), expressing insecticidal proteins of the bacterium Bacillus thuringiensis Berliner (i.e., Bt maize), on the associated arthropod assemblage in a neotropical scenario. Arthropods associated with winter and summer cultivations with Bt and non‐Bt (isoline) maize were thus sampled using sweep nets and whole‐plant collections throughout the plant phenological cycle. The collected information was used to build a plant‐consumer‐predator trivariate network based on data of individual arthropod body mass, numerical abundance, and biomass abundance using food web analysis. Eighty‐five arthropod species were sampled, and whereas cultivation season significantly affected arthropod species richness and abundance, only marginal differences existed between maize hybrids (Bt vs. non‐Bt). The recognized food webs also indicated significant differences between seasons. In contrast, Bt‐maize‐hosted food webs were similar to those of the non‐Bt isoline indicating no significant impact on arthropod food webs. Nonetheless, Bt maize did not provide significant control of the target pest species, the fall armyworm, nor did it lead to higher crop yield, raising questions about its current usefulness in the region.

Fire Severity Causes Temporal Changes in Ground-Dwelling Arthropod Assemblages of Patagonian Araucaria–Nothofagus Forests

Fire is one of the main drivers of anthropogenic disturbances in temperate forest ecosystems worldwide, with multiple effects spread across ecological networks. Nevertheless, the biodiversity effects of fire are poorly known for species-diverse groups such as arthropods. In this research, we used a burn gradient generated two and three years after a large fire event to assess how different levels of fire severity affect arthropod diversity in the forest with the main forest forming long-living tree species Araucaria araucana, in southern Chile. The species richness and abundance of arthropods among trophic guilds was estimated annually in four fire-severity levels. We found that arthropods responded differently to fire severity levels, depending on their trophic guilds and years after fire (two and three years after fire). During the second year after fire, zoophages, phytophages, and parasitoids were more diverse in areas with high fire severity within the second year after fire, as compared to those in areas with low severity or unburned stands. In the third year after fire, a change in this trend was observed, where the abundance of all groups dropped significantly, with positive changes in the diversity in zoophages, phytophages, polyphages and saprophages, which is more noticeable in sites with high severity. These results indicate that annual variation in environmental conditions triggers bottom-up cascading effects for arthropods. Forests stands severely impacted by fires support highly fluctuating and possibly unstable arthropod assemblages. Hence, restoration efforts should be focused on recovering microhabitat conditions in these stands to allow the persistence of arthropods.

The Effects of Five-Year Biosolid Application on the Diversity and Community of Soil Arthropods

Land application of biosolids is a beneficial form of management, although heavy metal contamination is a major concern. Biosolid application can shape the abundance, species richness, and community structure of arthropods, which are important regulators of soil processes. We investigated the effect of the five-year (2012–2017) application of domestic biosolids at 0, 15, 30, and 45 ton ha−1 on the soil properties, enzyme activity, heavy metal concentrations, abundance, and diversity of soil arthropods in degraded sandy soil. The results showed that the application of a high amount of biosolids resulted in an increase in soil organic carbon of 2.6 times and in the water content of 2.8 times compared with CK (no biosolids). The total metal concentrations of Cr, Ni, Cu, Zn, Cd, and Pb increased by 6.6%, 3.2%, 6.6%, 7.7%, 13.3%, and 22.5%, respectively, compared with CK in soil (p > 0.05). The activities of seven enzymes, which mainly participate in carbon (C), nitrogen (N), phosphate (P), and sulfur (S) transformation, increased by 1.53%~122.7%, indicating that the soil function did not change under biosolid application. The number of individual arthropods collected from a square meter of soil changed from 0 to 2560. The total abundance of arthropods increased from 1.2 to 4 times under biosolid application (p < 0.05), but biosolid application had no effects on simple measures of richness and diversity (Shannon–Weaver index). Multivariate ordination techniques showed a significant shift of the arthropod community structure under biosolid application due to differing responses of several taxa to the biosolids. Redundancy analysis highlighted the influential role of soil chemical properties (soil organic C, total N, water content, microbial biomass, and pH) and cadmium in shaping the soil arthropod structure. These results suggest that long-term biosolid application with limited heavy metal concentrations does not have detrimental effects on soil arthropods or microbial-related soil function.

Plant diversity promotes species richness and community stability of arthropods in organic farming

Plant diversity promotes species richness and community stability of arthropods in organic farming

Aboveground impacts of a belowground invader: how invasive earthworms alter aboveground arthropod communities in a northern North American forest.

Declining arthropod communities have recently gained a lot of attention, with climate and land-use change among the most frequently discussed drivers. Here, we focus on a seemingly underrepresented driver of arthropod community decline: biological invasions. For approximately 12 000 years, earthworms have been absent from wide parts of northern North America, but they have been re-introduced with dramatic consequences. Most studies investigating earthworm-invasion impacts focus on the belowground world, resulting in limited knowledge on aboveground-community changes. We present observational data on earthworm, plant and aboveground arthropod communities in 60 plots, distributed across areas with increasing invasion status (low, medium and high) in a Canadian forest. We analysed how earthworm-invasion status and biomass impact aboveground arthropod community abundance, biomass and species richness, and how earthworm impacts cascade across trophic levels. We sampled approximately 13 000 arthropods, dominated by Hemiptera, Diptera, Araneae, Thysanoptera and Hymenoptera. Total arthropod abundance, biomass and species richness declined significantly from areas of low to those with high invasion status, with reductions of 61, 27 and 18%, respectively. Structural equation models suggest that earthworms directly and indirectly impact arthropods across trophic levels. We show that earthworm invasion can alter aboveground multi-trophic arthropod communities and suggest that belowground invasions might be underappreciated drivers of aboveground arthropod decline.

Simulating selection and evolution at the community level using common garden data.

A key issue in evolutionary biology is whether selection acting at levels higher than the individual can cause evolutionary change. If it can, then conceptual and empirical studies must consider how selection operates at multiple levels of biological organization. Here, we test the hypothesis that estimates of broad‐sense community heritability, HC2, can be used to predict the evolutionary response by community‐level phenotypes when community‐level selection is imposed. Using an approach informed by classic quantitative genetics, we made three predictions. First, when we imposed community‐level selection, we expected a significant change in the average phenotype of arthropod communities associated with individual tree genotypes [we imposed selection by favoring high and low NMDS (nonmetric multidimensional scaling) scores that reflected differences in arthropod species richness, abundance and composition]. Second, we expected HC2 to predict the magnitude of the community‐level response. Third, we expected no significant change in average NMDS scores with community‐level selection imposed at random. We tested these hypotheses using three years of common garden data for 102 species comprising the arthropod communities, associated with nine clonally replicated Populus angustifolia genotypes. Each of our predictions were met. We conclude that estimates of HC2 account for the resemblance among communities sharing common ancestry, the persistence of community composition over time, and the outcome of selection when it occurs at the community level. Our results provide a means for exploring how this process leads to large‐scale community evolutionary change, and they identify the circumstances in which selection may routinely act at the community level.

Simple attributes predict the value of plants as hosts to fungal and arthropod communities

Fungal and arthropod consumers constitute the vast majority of global terrestrial biodiversity. Yet, the link from richness and composition of producer (plant) communities to the richness of consumer communities is poorly understood. Fungal and arthropod species richness could be a simple function of producer species richness at a site. Alternatively, it could be a complex function of chemical and structural properties of the producer species making up communities. We used databases on plant–fungus and plant–arthropod trophic links to derive the richness of consumer biota per associated plant species (coined link score). We assessed how well link scores could be predicted by simple attributes of plant species. Next, we used a multi‐taxon inventory of 130 sites, representing all major habitat types in a country (Denmark), to investigate whether link scores summed over plant species in communities (coined link sum) could outperform simple plant species richness as predictor of fungal and arthropod richness at the sites. We found plant species' link scores for both fungi and arthropods to be positively related to plant size, regional occupancy, nativeness and ectomycorrhizal status. Link‐based indices generally improved the prediction of richness of fungal and arthropod communities. For fungal communities, both observed link sum (from databases) and predicted link sum (from plant attributes) had high predictive power, while plant richness alone had none. For arthropod communities, predictive performance varied between functional groups. For both fungi and arthropods, richness predictions were further improved by considering abiotic habitat conditions. Our results underline the importance of plants as niche space for the megadiverse groups of arthropods and fungi. The plant–attribute approach holds promise for predicting local and regional consumer richness in areas of the world lacking detailed plant–consumer databases.

Metabarcoding of canopy arthropods reveals negative impacts of forestry insecticides on community structure across multiple taxa

Abstract Insecticides used to combat outbreaks of forest defoliators can adversely affect non‐target arthropods. Forestry insecticides typically suppress Lepidoptera larvae which are the cornerstone of the canopy community of deciduous oak forests. The abrupt removal of this dominant component of the food web could have far‐reaching implications for forest ecosystems, yet it is rarely investigated in practice owing to several methodological shortcomings. The taxonomic impediment and the biased nature of arthropod sampling techniques particularly impede the assessment of insecticide impacts on diverse communities. To tackle this issue, we propose an experimental approach combining sampling by pyrethrum knockdown and species determination via DNA metabarcoding, using community subsampling to derive estimates of species abundances. We applied this protocol to investigate the short‐term effects of the insecticides diflubenzuron (DFB) and Bacillus thuringiensis var. kurstaki (BTK) on canopy‐dwelling arthropod communities in German oak woodlands. Our approach allowed us to detect most of the diversity and integrate species abundances in our analyses. By classifying arthropod species into assemblages based on their expected sensitivity rather than coarse taxonomic groupings, we could unveil substantial effects of DFB across multiple taxa 5 weeks after application. Although strong effects on single species appear related to direct toxicity, substantial impacts of DFB on parasitoids and xylophagous beetles suggest that anti‐defoliator treatments can have previously unsuspected indirect effects on some components of forest arthropod communities. The impacts of BTK on community structure were consistent with that of DFB though much weaker. Synthesis and applications. Comparing diversity patterns in the arthropod communities of sprayed and unsprayed oak canopies, our results show that selective insecticides can alter species diversity in presumably non‐sensitive taxa. Even though the ecological significance of these impacts has yet to be assessed in an operational setting, their existence calls for increased regulatory scrutiny on indirect effects. As community approaches become more attainable with the rapid development of DNA metabarcoding, we suggest the inclusion of community‐level end points as regulatory requirements for the approval of forest‐use insecticides.

Local environmental context determines the colonisation of leaf shelters by arthropods: an experimental study

Abstract The magnitude of facilitation by shelter-building engineers on community structure is expected to be greater when they increase limited resources in the environment. We evaluated the influence of local environmental context on the colonisation of leaf shelters by arthropods in a Mexican evergreen tropical rainforest. We compared the species richness and abundance of arthropods (total and for different guilds) colonising artificially rolled leaves in habitats differing in understory heterogeneity (forest edge > old-growth forests > living fences). Arthropod abundance of the most representative arthropod taxa (i.e., Araneae, Blattodea, Collembola and Psocoptera) colonising the rolled leaves was greater at forest edge, a trend also observed for average arthropod abundance, and for detritivore and predator guilds. In addition, fewer arthropod species and individuals colonised the rolled leaves in the living fence habitat, a trend also observed for most arthropod guilds. As forest edge is expected to have a greater arthropod diversity and stronger density-dependent interactions, a greater limitation of refuges from competitors or predators may have determined the higher colonisation of the rolled leaves in this habitat. Our results demonstrate that local environment context is an important factor that affects the colonisation of arthropods in leaf shelters.

Present and historical landscape structure shapes current species richness in Central European grasslands

ContextCurrent diversity and species composition of ecological communities can often not exclusively be explained by present land use and landscape structure. Historical land use may have considerably influenced ecosystems and their properties for decades and centuries.ObjectivesWe analysed the effects of present and historical landscape structure on plant and arthropod species richness in temperate grasslands, using data from comprehensive plant and arthropod assessments across three regions in Germany and maps of current and historical land cover from three time periods between 1820 and 2016.MethodsWe calculated local, grassland class and landscape scale metrics for 150 grassland plots. Class and landscape scale metrics were calculated in buffer zones of 100 to 2000 m around the plots. We considered effects on total species richness as well as on the richness of species subsets determined by taxonomy and functional traits related to habitat use, dispersal and feeding.ResultsOverall, models containing a combination of present and historical landscape metrics showed the best fit for several functional groups. Comparing three historical time periods, data from the 1820/50s was among the most frequent significant time periods in our models (29.7% of all significant variables).ConclusionsOur results suggest that the historical landscape structure is an important predictor of current species richness across different taxa and functional groups. This needs to be considered to better identify priority sites for conservation and to design biodiversity-friendly land use practices that will affect landscape structure in the future.

沙障对流动沙丘区地表节肢动物分布及多样性的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 沙障对流动沙丘区地表节肢动物分布及多样性的影响 DOI: 10.5846/stxb202108182294 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 中国科学院战略性先导科技专项A（XDA23060304）；国家自然科学基金项目（41771290） Effects of sand barriers on the distribution and diversity of ground arthropods in the active sandy dune regions Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:沙障作为人工固沙植被恢复与保护绿洲和道路安全的一种手段，可以有效阻止沙丘移动，改变流动沙丘地表生态水文过程，进而影响节肢动物多样性及营养结构及功能变化。鉴于此，选取临泽县中部沙带为研究区，利用陷阱法系统调查了生物、物理沙障和流动沙丘区沙丘不同部位地表节肢动物分布及多样性。研究结果表明，沙障营建强烈影响了流动沙丘区地表节肢动物组成，生物和物理沙障区地表节肢动物的活动密度、物种丰富度及多样性均显著高于流动沙丘区，捕食性和其它食性节肢动物较植食性节肢动物对沙障营建的响应更为敏感。沙障还改变了沙丘地表节肢动物的分布规律，生物和物理沙障区地表节肢动物的活动密度从沙丘底部到顶部依次增加，而流动沙丘区地表节肢动物主要分布在沙丘中下部。谢氏宽漠王和尖尾东鳖甲在流动沙丘区主要分布沙丘的中下部，沙障营建导致沙丘顶部谢氏宽漠王和尖尾东鳖甲的活动密度大幅提高。此外，研究还发现生物和物理沙障对地表节肢动物的影响不同，生物沙障区地表节肢动物活动密度显著高于物理沙障区，捕食性和东鳖甲属等其它食性节肢动物的活动密度在生物沙障区均高于物理沙障区。总之，沙障营建及类型差异强烈影响地表节肢动物的分布及多样性，它通过资源上行效应和土壤物理环境的改变提高了地表节肢动物的多样性及营养结构，从而影响了土壤生态系统结构及功能变化过程。 Abstract:As a means of artificial sand fixation for vegetation restoration and protection for oases and road safety, sand barrier can effectively prevent the movement of sand dunes, strongly affect the distribution and diversity of ground arthropods by altering abiotic and biotic environment on the surface of the dunes. Moreover, sand barrier also impacted on the trophic structure and ecological function of ground arthropods by changing the surface eco-hydrological process of active sandy dune regions. Therefore, we select the middle sand strip as the object of study in Linze County in the middle reaches of Heihe River Basin and systematically researched on the distribution and diversity of ground arthropods using pitfall trapping in the biological sand barrier, physical sand barrier and active sandy dune regions. The key results are as follows. Sand barrier strongly affected the assemblage of ground arthropod community. The activity density, species richness and diversity index of ground arthropods in the biological sand barrier and physical sand barrier regions were significantly higher than those in active sandy dune regions apparently. Comparing with the phytophagous arthropods, the predatory arthropods and other arthropods response was more sensitive to sand barrier construction. Sand barrier also changed the distribution pattern of ground arthropods in the upper, middle and bottom of sandy dune. The activity density of ground arthropods in biological sand barrier and physical sand barrier regions increased from the top to the bottom of the sandy dune gradually. Conversely, it distributed in the middle and bottom of sandy dune in the active sandy dune regions which was related to the quantity changes of ground-dwelling arthropods species that preferred to move in the active sandy dune regions. More Mantichorula semenowi and Anatolica mucronate were collected at the middle of bottom of sandy dune in the active sandy dune regions, and those beetles were collected at the up of sandy dune in the biological sand barrier and physical sand barrier regions. Besides, it was also found that the influences on ground arthropod assemblage of biological sand barrier and physical sand barrier were different. The activity density of ground arthropods in the biological sand barrier regions was higher than physical sand barrier regions. A similar pattern was observed on the activity density of predatory arthropods and other arthropods like Tentyria sp. In conclusion, sand barrier presence and its types strongly affected on the diversity and trophic structure of ground arthropods community. It significantly improved the number of individuals and diversity of ground arthropods by bottom-up effect of resource and changes of the soil physical environment, accelerating the process of soil ecosystem structure and functional change in the desert ecosystem. 参考文献 相似文献 引证文献

Landscape- and time-dependent benefits of wildflower areas to ground-dwelling arthropods

Wildflower areas are a popular agri-environment scheme to counteract agro-biodiversity loss. Yet, their benefits are controversially discussed. Since inconsistent benefits may be owed to landscape context and temporal dynamics, we applied a multi-year study to unravel effects of permanent and transient habitats on ground-dwelling arthropods in wildflower areas and cereal fields.Across three consecutive years, we studied activity density, species richness and community composition of rove beetles, carabid beetles and spiders in ten pairs of wildflower areas and cereal fields along independent gradients of proportions of permanent semi-natural habitats or transient wildflower areas.Arthropod responses to the proportions of permanent semi-natural habitats often followed a hump-shaped pattern, whereas transient wildflower areas seemed to drive linear responses. An interactive effect on rove beetle richness in wildflower areas implies that benefits were highest either at intermediate proportions of permanent semi-natural habitats or at lower proportions, but with additional availability of transient wildflower areas or in landscapes with low proportions of permanent semi-natural habitats, but high proportions of wildflower areas. However, ground-dwelling arthropod activity density or species richness did not systematically increase over the three study years.Our results suggest that both permanent and transient habitats differ in how they affect biodiversity, possibly due to different temporal continuity and resource diversity. Benefits of permanent semi-natural habitats seemed highest at an equilibrium between an increasing resource-related species pool and an increasing diversity dilution, whereas benefits of transient wildflower areas seemed to increase with resource complementarity and connectivity at the landscape scale. Nevertheless, both habitats seem to complement each other and considered in concert, seem to be most effective in promoting benefits of wildflower areas to ground-dwelling arthropods at intermediate landscape complexity. The substantial variation in diversity patterns among years with weather extremes, suggests that optimizing benefits of wildflower areas requires further multi-year studies.

Future climate and land-use intensification modify arthropod community structure

Climate change and land-use intensification pose increasing threats to biodiversity, with climate change expected to eventually surpass other global environmental change drivers and become the greatest threat to biodiversity in the future. Understanding the combined ecological impacts of multiple global change drivers is crucial to predict future scenarios of biodiversity change. However, experimental evidence for the impacts of land-use intensification under current and future climate scenarios is lacking, even though this is imperative for understanding future trajectories of biodiversity in agricultural landscapes. We experimentally tested for the simultaneous effects of land-use intensification and climate change on arthropod biodiversity in a field-scale grassland experiment known as the Global Change Experimental Facility (GCEF). Specifically, we tested whether future scenarios of climate change are likely to exacerbate impacts of land-use intensification on arthropod diversity and abundance across different trophic levels by sampling aboveground arthropod communities in low and high land-use intensity grasslands under current and future climatic conditions. We found that climate change reduced total abundances of arthropods and increased evenness of the whole community, while only having trophic level-specific effects on detritivore abundance and evenness. Land-use intensification reduced abundance of the whole community, predators and detritivores, but only eroded species richness of the whole community and herbivores, with the magnitude of declines in predator and detritivore abundance depending on the climate scenario. Additionally, both land-use intensification and climate altered species composition of the whole community and within the predator, herbivore, and detritivore trophic levels. We show that climate change and land use intensification cause simultaneous shifts in arthropod abundance, species richness, and species composition across trophic levels. Changes in arthropod communities as a result of climate change and land-use intensification will likely have profound consequences for ecosystem functioning under future environmental conditions.

Increasing landscape complexity enhances species richness of farmland arthropods, agri-environment schemes also abundance – A meta-analysis

Intensification of agricultural production and simplification of landscape structure have negatively affected arthropod communities, in particular since the end of Second World War. Agri-environment schemes may partly compensate for these losses and enhance arthropod populations, but their effectiveness is higher in simple landscapes rather than complex landscapes, characterized by a large proportion and diversity of semi-natural areas. As the landscape-scale species pool is known to drive local species richness, we tested our hypothesis that landscape complexity determines local arthropod species richness, whereas local management affects only arthropod abundance. Here we undertake a meta-analysis as part of a wider systematic review of the effects of land use heterogeneity on arthropod species richness. We searched for studies quantifying the effects of agri-environment schemes (e.g. wildflower strips/areas, grassy field margins, organic farming) and landscape complexity on arthropod richness and abundance. We additionally separated vegetation- vs. ground-dwelling taxa, because the effects were hypothesized to be greater in the more mobile vegetation-dwelling taxa. As expected, increasing landscape complexity enhanced arthropod richness, but not their abundance. Unexpectedly, agri-environment schemes did not only support the abundance of arthropods, but also their species richness. This pattern was driven by the vegetation-dwelling, not the ground-dwelling taxa, presumably because the higher mobility of vegetation-dwelling taxa allows faster responses to environmental changes. Our results show that agri-environment schemes in Europe benefit both arthropod abundance and species richness, whereas increasing landscape complexity primarily enhances species richness. This is why both local and landscape management need to be taken into account to halt current biodiversity losses in agricultural landscapes. Agri-environment schemes need to be implemented at a larger spatial and temporal scales to enhance landscape complexity, maintaining or restoring biodiversity sustainably.

Mistletoe infection changes arthropod community on its cactus host through indirect effects

Abstract Parasitic plants and herbivores show similarities in their interactions with host plants. Herbivore‐induced resistance/susceptibility in plants can scale up to the arthropod community. Similar evidence regarding parasitic plants is scarce. We evaluated the indirect effects initiated by the mistletoe Tristerix aphyllus on the arthropod community of the cactus Echinopsis chiloensis in the Chilean coastal desert. Field observations suggested that a stem‐borer beetle bores more brood chambers in mistletoe‐parasitised cacti than in non‐parasitised cacti, and that arthropods colonise these chambers. We compared tissue toughness, chamber density and morphology in mistletoe‐parasitised and non‐parasitised cacti. We also compared richness, total abundance, abundance per taxa, diversity and composition of the colonising arthropod community. Parasitised cacti showed a 14% reduction in tissue toughness. Chamber density in parasitised cacti was four times greater and chambers were larger: 35% more volume, an entrance‐opening area 30% greater, and twice the area of the maximum‐width section. Arthropod species richness and diversity were higher in chambers of parasitised cacti. Arthropod community composition was different in chambers of parasitised and non‐parasitised cacti. Thus, spiders and moths were more abundant in parasitised cacti, and pseudoscorpions, scolopendras, ants and flies were exclusively present there, while non‐parasitised cacti had no exclusive taxa. Mistletoe infection results in a richer, more diverse and distinct arthropod community on its cactus host, which occurs through induced susceptibility to stem‐borers whose brood chambers are colonised by arthropods. Tristerix aphyllus could be a key‐stone species in these arid ecosystems, where arthropod diversity is relatively low.