Grasshopper Species Richness Research Articles

Grassland nature reserves safeguard a high species richness and biomass of grasshoppers

Abstract In the course of land‐use change, especially since the mid‐20th century, the area of semi‐natural (unimproved) grasslands has dramatically decreased. One way to counteract this process is to designate nature reserves. However, the effectiveness of nature reserves is controversial. The aim of our study was to evaluate the environmental drivers of species richness and biomass of Orthoptera (hereinafter termed ‘grasshoppers’) in grasslands inside nature reserves and within the intensively used agriculture landscape (hereinafter termed ‘wider countryside’). For this purpose, we sampled the grasshoppers at the landscape scale in 45 randomly selected plots. Each plot had a size of 5 ha. The abundance of grasshoppers, as a basis for the biomass calculation, was recorded at the habitat scale in 20 meadow patches (500 m2 each). In addition, various environmental parameters such as habitat diversity, mowing intensity and vegetation structure were determined at the landscape and habitat scale. Our results illustrate the importance of nature reserves for the conservation of grasshoppers. Control plots in the wider countryside harboured fewer species than plots within nature reserves. The differences were even clearer among threatened species. On average, plots in nature reserves had almost twice as many threatened species than control plots in the wider countryside. The comparison revealed similar patterns at the habitat scale: both the number of species and biomass were higher in nature reserves. At the landscape scale, number of species were best explained by the amount of wet grassland and habitat diversity. We identified mowing intensity and to a lower extend the degree of drainage as the key drivers of species richness and biomass at the habitat scale. Synthesis and applications: To preserve biodiversity in nature reserves, we recommend (i) leaving uncut refuges during mowing and (ii) blocking drainage to stabilise the water level. Both measures contribute to a high species number and abundance of grasshoppers and many other insects. An effective conservation measure to promote species richness in the wider countryside would be to increase habitat diversity. This can be done by creating or restoring fallow islands, field margins, fringes and hedgerows.

Diversity, species richness and distribution of grasshoppers (Orthoptera: Acrididae) in Khairpur Sindh Pakistan

Diversity, species richness and distribution of grasshoppers (Orthoptera: Acrididae) in Khairpur Sindh Pakistan

Maintaining habitat diversity at small scales benefits wild bees and pollination services in mountain apple orchards

Abstract Landscape context influences wild bee abundance and diversity, alongside pollination‐related services. Growing evidence supports the positive effects of landscape heterogeneity on bee diversity and fruit production for pollination‐dependent crops in flatlands. However, little remains known about these relationships in mountainous environments where the landscape matrix surrounding crops is often more complex than in lowlands. We conducted our study in apple orchards in South Tyrol, an Alpine region in Italy, using pan‐traps, direct observations of visitation frequency and a pollinator exclusion experiment. We investigated the scale‐dependent effects of landscape heterogeneity and other parameters on wild bee assemblages and the related pollination service they provide at five spatial scales (radius 100–2000 m). We found that landscape heterogeneity positively affected the abundance and richness of wild bees, with the strongest effect at 500 m. We calculated a multidiversity index, reflecting the land‐use intensity based on the species richness of vascular plants, grasshoppers, butterflies, birds and bats. We identified a positive relationship between this multidiversity index and wild bee richness. Additionally, we found that visitation rate of wild bees was negatively affected by crop cover and that abundance of honeybees did not influence wild bee visitation rate or reproductive success. Finally, reproductive success was positively related to semi‐natural habitat cover. Landscape heterogeneity should be maintained in apple orchards to continue to reap the benefits of vital pollination‐related services. Diversification strategies should be implemented to promote habitat diversity at small scales, even in regions with more than 80% of (semi‐)natural habitats.

Intensity of grassland management and landscape heterogeneity determine species richness of insects in fragmented hay meadows

Traditionally managed grasslands rank among the most species-rich ecosystems. However, in agricultural landscapes of Western and Central Europe, their extent has severely decreased. The remaining patches are mostly fragmented and suffer from habitat deterioration. Here, we studied the effects of environmental conditions on species richness of butterflies and grasshoppers in highly fragmented hay meadows. Our study revealed that environmental parameters at the habitat and landscape level influenced species richness of butterflies and grasshoppers in low-intensity hay meadows. In the univariable models, two groups of parameters consistently affected the number of all and threatened species: at the habitat level, species richness was fostered by structural richness, which was indicative of the overall management intensity of the grassland patches. At the landscape level, a higher number of mowing events in the landscape surrounding the hay meadows had a negative effect and higher elevations exhibiting a cooler and wetter climate had a positive effect on species richness. The former reflected the overall intensity of grassland management in the landscape and the later, together with further predictors (cover of forest, habitat connectivity, slope), the landscape heterogeneity. Consequently, the intensity of grassland management at the habitat and landscape level as well as the landscape heterogeneity, which was also related to land-use intensity, determined species richness of butterflies and grasshoppers. Based on these findings, there is an urgent need to enlarge the proportion of grasslands with low land-use intensity in the wider countryside. Additionally, conservation measures should aim at increasing landscape heterogeneity and habitat connectivity.

Rapid response of vascular plants and insects to restoration of montane grasslands

IntroductionIndustrialization has ushered in massive changes in agriculture. Particularly in low mountain ranges, large-scale afforestation with Norway spruce on traditionally managed, semi-natural grasslands has caused a severe decline in biodiversity. Tree removal, hay transfer and resumption of grazing or mowing are typical measures to re-create species-rich grasslands. The aim of this study was to use vascular plants and three insect taxa (leafhoppers, true bugs, and grasshoppers) as bioindicators to evaluate the success of montane grassland restoration on former spruce forests in Central Europe. In addition, we intended to identify the drivers of species richness within the studied grasslands in order to derive suitable recommendations for habitat management.MethodsWe analyzed two different treatments: (i) grazed restoration sites where trees had been cut and species-rich green hay had been applied (N = 9) and (ii) target sites with a long continuity of low-intensity grazing (N = 9).Results and DiscussionOur study revealed that all studied taxa responded rapidly to the restoration measures. After a development period of 3 to 5 years, we found no differences in species richness and diversity of leafhoppers, true bugs and grasshoppers (all, target and threatened species). In addition, non-metric multidimensional scaling showed a large overlap in species composition between restoration and target grasslands. Among target and threatened species, vascular plants displayed the same pattern as insects and reached similar values when comparing the two treatments. However, total species richness and diversity of vascular plants were still higher on the target sites and species composition overlapped only partially. Grazing intensity was the predictor with the highest explanatory power in multivariable (Generalized) Linear Mixed-effects Models, being negatively related to species richness of leafhoppers and true bugs. We conclude that the measures implemented were effective in re-establishing target communities of different taxa. The transfer of seed-containing hay enabled or accelerated the development of the vegetation. Insects, on the other hand, were able to recolonize the restored grasslands on their own, given that these sites were embedded in a network of species-rich grasslands. With regard to insects (e.g., leafhoppers and true bugs), it should be ensured that grazing is applied at low intensity.

Effects of experimental rewilding on butterflies, bumblebees and grasshoppers

Grassland ecosystems are species-rich habitats that are rapidly declining globally posing serious concerns for biodiversity conservation. This situation is particularly relevant in agricultural areas in Europe. As traditional management practices and livestock grazing regimes ceased, rewilding could be a potential avenue to tackle current biodiversity declines. To test this hypothesis, we set up a 3-year experiment where 12 horses were introduced in three 10-hectare enclosure replicates (four horses per enclosure). Horses were kept without supplementary feeding to mimic ecosystem functions of wild horses. We applied Generalized Linear Mixed Effects Models and a backward stepwise model selection procedure to elucidate factors that modulate insect richness induced by grazing. Our results show that plant species richness, the proportion of flowers and plant height play a significant role for butterfly and bumblebee richness, while the opposite effect was detected for grasshoppers. However, the effect on grasshoppers was counterbalanced by increased grasshopper species richness in habitats adjacent to horse latrines.Implications for insect conservationRewilding with horses may offset current biodiversity declines by maintaining important functional links between plants and pollinators in grassland ecosystems. Horse grazing can however have different effects on diverse functional groups of insects. Application of integrative landscape scale approaches may be needed to elucidate the effects of rewilding for certain functional groups such as grasshoppers. With current biodiversity declines, up-scaling rewilding research and practice might be crucial to mitigate the pervasive effects on insects as their services and functions are critical for our existence.

Assessing grasshopper communities in mountainous meadows – a comparison of a visual‐acoustic and a novel, purely acoustic soundscape method

AbstractGrasshoppers (Orthoptera, suborders Ensifera and Caelifera) are often used as bioindicators to assess the effects of human‐induced land‐use changes. However, such assessment is largely depending on the methods that provide an accurate estimation. In the present study, we compared grasshopper species richness and assemblages on mountainous meadows in the Austrian Alps by applying a commonly used visual‐acoustic method and a novel soundscape method. For the visual‐acoustic method, we walked through the meadows for 1 h at a slow pace and recorded any visually and acoustically noticeable species. For the soundscape method, sound recorders combined with bat detectors were installed at fixed positions. Comparing both methods, there was no significant difference in species richness; however, we found significantly higher numbers of Caelifera species with the visual‐acoustic method and marginally higher numbers of Ensifera species with the soundscape method. Grasshopper assemblages differed marginally significantly between the two methods. With the soundscape method significantly more species were found between 12:00 and 17:00 hours compared to the samples taken between 10:00 and 12:00 hours. The soundscape method represents a reliable and by the observer unbiased technique to investigate grasshoppers within their environment. The visual‐acoustic method is especially preferable for the detection of non‐stridulating species which cannot be assessed with the soundscape method. Thus, researchers might consider using a sampling plan that mixes different sampling methods in order to offset potential limitations in sampling grasshopper species.

Traditional grazing management creates heterogeneous swards and fosters grasshopper densities

Common pastures were once the dominant type of land use in many European regions. However, during the past 150 years, they have declined dramatically. Recent studies have shown that they are hotspots for rare plant, butterfly, and bird species in the study area, the Bavarian pre-Alps (southern Germany). However, studies on the value of these pastures for Orthoptera (hereinafter termed "grasshoppers") have been scarce. Here, we studied the effects of traditional summer grazing in common pastures on grasshopper assemblages. Our study revealed that grasshopper species richness did not differ between common pastures (n=57) and controls (n=57). By contrast, density of all and of threatened species varied between common pastures and controls in all plots and within the two vegetation types with the highest grasshopper abundance, grasslands on mineral soil and fens. Two threatened species, Pseudochorthippus montanus and Stethophyma grossum, were identified as indicators for common pastures; controls had no indicative species. Traditional low-intensity grazing in common pastures has resulted in open and heterogeneous swards with some bare ground, a low cover of litter and an intermediate vegetation height favouring high densities of grasshopper species in general and threatened species in particular. This is especially true for the two most productive vegetation types, grasslands on mineral soil and fens. To promote biodiversity in general and grasshopper densities in particular, we recommend maintaining traditional cattle grazing (stocking capacities: 0.5-2.0 livestock units/ha) in common pastures. Where possible, this grazing regime should also be introduced in the surrounding landscape.

Simple Assessment of Temperate Grassland Suitability as Habitat for Three Insect Taxa

We propose a set of indicators to evaluate how grazing by livestock and grassland management can help preserve biodiversity in the insect communities of grassland ecosystems. These indicators can be calculated for any grassland for which management and botanical composition are known, and they do not require advanced knowledge on conservation biology and entomology. Based on the scientific literature and expert interviews, each indicator combines pressure (i.e., 16 management classes) and state variables (i.e., sward botanical composition and several of the plant functional characteristics) to assess the effects on butterfly, bumblebee, and grasshopper abundance and species richness. Each indicator was based on a multicriteria decision tree with fuzzy partitioning to account for uncertainty in the threshold values between different alternatives. The output validation of indicators was performed by comparing decision tree output with standardized measurements from 10 surveys across France, Germany, Switzerland, Wales, and Italy. The prediction of grassland suitability for butterflies was more accurate for butterfly species richness (P < 0.05) than for butterfly abundance (P = 0.10), as even under standardized transect counts, recorders will observe disproportionately more individuals when it is sunny and warm. The sensitivity of the butterfly species richness indicator was then tested using an independent dataset of 395 French grasslands. There were significant differences in predicted species richness (χ215 = 121.16; P < 0.05) among the 16 management classes, and they were ranked consistently in spite of very parsimonious assumptions in the decision tree. The prediction of grassland suitability was good for bumblebee abundance (P < 0.05) and species richness (P < 0.01). This prediction was also successful for grasshopper abundance (P < 0.05) and species richness (P = 0.05), all outliers coming from a highly diverse grassland community located on shallow soil in the Italian survey. This set of indicators can thus provide a cost-effective evaluation of temperate grassland suitability as habitat for three insect taxa. These indicators have more relevance than general insect species richness, and their application does not require any entomological skill. The indicators can help stakeholders to make adequate decisions for insect conservation in grassland ecosystems, but do not have direct applicability to higher conservation value taxa or species.

Grasshopper diversity in several agricultural areas and savannas in Dompu, Sumbawa Island, Indonesia

Abstract. Leksono AS, Yanuwiadi B, Khotimah A, Zairina A. 2021. Grasshopper diversity in several agricultural areas and savannas in Dompu, Sumbawa Island, Indonesia. Biodiversitas 23: 75-80. In Sumbawa Island, the conversion of forests and savannahs into agricultural land has increased rapidly since 2010. This research aims to compare grasshopper species' abundance, richness, and diversity between several farmland and savannas in Dompu, Sumbawa Island. It was conducted at ten locations in Dompu, Sumbawa Island, and included an ecotone, two post-harvested rice farms, two post-harvested corn farms, a mixed farm, a vegetable farm, and three savannas. Furthermore, samples were taken four times from four plots at each location in the post-harvest period from August to September 2021. Grasshopper sampling was carried out using the sweeping method with an insect net with each plot size of 2 x 10 m2. A total of 2264 individual grasshoppers belonging to 30 species and four families were collected from all research sites. The dominant species were Alloteratura sp., Trilophidia annulata, Atractomorpha crenulata, Phlaeoba fumosa, Oxya japonica and, Phlaeoba infumata. The greatest grasshopper species richness and diversity were found in post-harvest rice farms, while the lowest was in the vegetable farm, and most of these species are considered pests. This research shows that the composition of grasshoppers on agricultural land is very similar to that of the adjacent savannah. Hence, monitoring and controlling their presence is necessary by paying attention to savannas as refuge land.

Grasshopper country before and after: a resurvey of Ken Key's collecting expeditions in New South Wales, Australia, 70 years on

AbstractRecent reports of insect declines across Europe and other parts of the world have emphasised the generally poor baseline that exists for assessing changes in biodiversity. One important source of untapped baseline distribution data is field notebooks, which are often associated with the collection activities of museums and other scientific institutions and may be decades or even centuries old. Over 220 field notebooks are associated with the grasshopper (Caelifera) collection in the Australian National Insect Collection, containing detailed notes on the times and places species were collected as well as vegetation and soil descriptions. In 2019, we resurveyed 45 locations from three of these notebooks from the 1940s, to assess the potential value of larger‐scale efforts in the future. We found substantial differences in grasshopper species richness and composition between the surveys; richness was generally higher in our survey, and some species showed dramatic increases in range and occurrence, whereas others remained relatively static. There was also evidence for vegetation state transitions in some areas, including increased weediness and shrub thickening, which may be associated with changes in the grasshopper fauna. We developed approaches for comparing environmental conditions across surveys and found that our species richness and abundance estimates were positively correlated with rainfall in the year preceding each survey. We conclude that further resurvey work on these field notebooks will provide a strong baseline picture of the diversity, distribution and abundance of the Australian grasshopper fauna for assessments of future change and may also give new insights about associated vegetation changes.

The abundance and diversity of grasshopper communities in relation to elevation and land use in Malang, Indonesia

Abstract. Leksono AS, Yanuwiadi B, Afandhi A, Farhan M, Zairina A. 2020. The abundance and diversity of grasshopper communities in relation to elevation and land use in Malang, Indonesia. Biodiversitas 21: 5614-5620. Ecological factors include interactions of the community members with numerous biotic and abiotic factors such as temperature, humidity, precipitation, light intensity, and seasonality show an altitudinal gradient. Most grasshopper species play a role as herbivores and are a good source of protein for other animals such as amphibians, small reptiles, birds, and small mammals. This study aimed to analyze variations in the abundance, richness, and diversity of grasshopper species along an altitudinal gradient. This research was conducted in five locations in Malang District, East Java, Indonesia, namely Bantur, Sumber Pujung Lawang, Pujon, and Poncokusumo. Grasshopper sampling was carried out by the sweeping method using an insect net. Sweepings were carried out on four plots with each plot size of 2 x 10 m2. Sampling was conducted four times from June to August 2020. The data were analyzed using the Shannon Wiener index (diversity analysis) and the Bray-Curtis index. The differences between locations were tested by one-way analysis of variance. Land use was analyzed by ArcGIS, using Landsat imagery 8. The abundance of grasshoppers had a significant negative correlation with elevation. That correlation was positive to species richness and diversity of grasshoppers. That with species diversity was significant, while that with species richness was not significant. The greatest abundance of the grasshopper was found in the middle elevation in Lawang (19.39 ± 2.12). In contrast, the highest species richness and diversity were found in the highest elevation in Poncokusumo (richness = 15.75 ± 1.60 and H '= 2.58 ± 0.11). Land use variation was not significant on abundance, species, richness, and diversity of grasshoppers. Interestingly, the high similarity of the grasshopper compositions in low elevation habitats was detected, indicating that land use in the low land area was remarkable. The abundance of grasshopper had a significant positive correlation with temperature but negatively correlated with humidity. There was no significant correlation among species richness, species diversity with temperature and humidity.

A Checklist of Short-horned Grasshopper Species (Orthoptera: Caelifera) from Littoral Region of Cameroon with description of a new species of the genus Hemierianthus Saussure, 1903 (Orthoptera: Chorotypidae).

The Littoral Region of Cameroon is one of the most highly disturbed regions in Cameroon that remain poorly studied and where no investigation regarding the grasshopper fauna has been conducted. Hence a survey was conducted from August 2015 to November 2018 in 11 localities of this region. In each locality, grasshoppers were sampled in three vegetation types (forests, fallows and cultivated farms) using sweep nets sampling method. We collected in total 51 short-horned grasshopper species belonging to the families Acrididae, Chorotypidae, Euschmidtiidae, Pyrgomorphidae and Thericleidae. Among these species, 43 belong to Acrididae, 5 to Pyrgomorphidae and only one belongs to the Chorotypidae, Euschmidtiidae and Thericleidae respectively. The Chorotypidae species Hemierianthus mbongueensis Yetchom Xu sp.nov. is also described in this study. Twelve grasshopper species were widely distributed as they occurred in all study sites and 11 were recorded exclusively from one study site. This study showed that there is high species richness of short-horned grasshoppers in the Littoral Region of Cameroon. However, more sampling effort in different ecosystems of this region and other regions of Cameroon will certainly improve our understanding on grasshopper taxonomy, ecology and biogeography.

<p><strong>Grasshopper (Orthoptera: Acrididea) assemblages in forests and savanna areas in Center, West and South-west regions of Cameroon</strong></p>

Forest degradation due to human activities is a major threat to the long-term persistence of many species. It affects species richness, abundance and can lead to the extinction of some species. The present work aimed at identifying the effect of environmental variations on the species richness and composition of grasshoppers in three regions Cameroon. In each region, four vegetations (forests, agroforests, fallows and crop fields) were investigated using sweep nets and pitfalls trapping for specimens’ capture from February 2016 to February 2018. From this study, 92 grasshoppers species belonging to 3 families, 13 subfamilies and 70 genera were collected. The Acrididae was the most diverse family with 77 species. The Catantopinae was the richest subfamily (22 species), while the Pterotiltus was the richest genus with 7 species. Overall, the average sample success was 92.49%. We found that the species richness was strongly influenced by the study site (region), the vegetation type, and the capture method. The dissimilarity index revealed that the grasshopper communities of West and Center region were similar to each other, like those of fallows and crop fields. Twenty-four species of grasshopper could be reported for the first time in Cameroon. This study updates the database on the grasshopper fauna of Cameroon and brings to 238 the number of grasshopper species known in Cameroon. Key words: Grasshoppers, species richness, forests, agroforests, fallows, crop fields

The value of newly created wood pastures for bird and grasshopper conservation

Modern production forests in Europe have closed canopies. As a consequence, the biodiversity associated with open woodland is declining. Forest grazing that created open conditions was once widespread. It was largely abandoned during the 20th century but is currently receiving increasing attention as a tool in nature conservation. In order to elucidate the value of newly created wood pastures for the conservation of birds and grasshoppers we selected nine wood pastures (WP) in southern Rhineland-Palatinate (Germany). In most of them part of the trees had been removed to create more open conditions. We selected adjacent ungrazed forests (F) and open pastures (OP) for comparison. Birds were recorded via territory mapping, grasshoppers via standardised transect surveys. We found higher bird species richness in WP compared to F and OP and more breeding pairs per area compared to open pastures. Target species for conservation like European nightjar (Caprimulgus europaeus) were only recorded in WP. Grasshopper species richness in WP and OP was similar but low in F. Species with conservation relevance only occurred in WP and OP. Community composition of both taxa differed between habitat types and β-diversity of birds was significantly higher among WP than among F and OP. We conclude that even in recently established sites, canopy opening in connection with grazing is a very effective tool in nature conservation, especially in order to promote species that favour open, structurally diverse forest habitats.

Biosolids application increases grasshopper abundance in the short term in a northern Canadian grassland

Degraded grasslands are common worldwide, often due to overgrazing by livestock; such degradation often reduces plant growth and water quality, while increasing soil erosion, wildfires, and invasive species. Recent restoration efforts have used organic amendments to increase soil nutrients, improve water retention, and increase forage production. Biosolids, the stabilised and pathogen-treated remains from wastewater treatment plants, have strong impacts on soil nutrients and plant growth, but there is very little known about impacts on higher trophic levels. We worked on northern grasslands in British Columbia, Canada, to test whether biosolids applications changed grasshopper abundances, body sizes, or species richness. We used hoop transects to measure density and timed net samples to determine richness and evenness. There were significantly higher (~3.8×) grasshopper densities at sites where biosolids were applied 1–2 years before sampling compared with control sites or sites where biosolids were applied in the year of sampling. Tibia lengths of grasshoppers varied with treatment, species, and sex, but there was no clear signature of biosolids leading to bigger body sizes. There were no significant differences in species richness or equitability in relation to the year of the biosolids application. Collectively, our results show that biosolids have large impacts on grasshopper densities, but no clear impact on community structure or body size. Because grasshoppers can be dominant insect herbivores and are critical prey for many birds and mammals, our results suggest biosolids could be an important tool in the context of site restoration or efforts to improve populations of insectivorous vertebrates.

Is cattle grazing more important than landscape heterogeneity for grasshoppers in Afromontane grassland?

Overgrazing is a major driver of habitat degradation, especially in southern Africa. Although grasshoppers are adapted to and benefit from natural disturbances, such as grazing by indigenous game and burning, we do not know how they respond to heavy cattle grazing, and how this response interacts with different fire regimes. We also do not know whether grasshoppers respond principally to these disturbances, to changes in the vegetation layer, or to larger landscape attributes (e.g. elevation). We addressed these questions in the topographically heterogeneous Central Midlands of KwaZulu-Natal Province, South Africa. We compared grasshopper assemblages among sites differing in grazing intensity (light, moderate and heavy), fire regime, rocky outcrops and vegetation structure, and attributes of landscape heterogeneity. The local environment (rocky outcrops, bare ground cover, grass height and total vegetation cover) was more important than landscape attributes for all measures of diversity. Grasshopper species richness was best explained by grazing intensity, with the specific response determined by fire regime. Greatest species richness was consistently recorded in heavily-grazed grassland. Thus, we found no evidence in support of the Intermediate Disturbance Hypothesis. Grasshopper assemblage composition of areas with light grazing was different from those with heavy grazing, but areas with light grazing were similar to those with moderate grazing under all fire regimes. Different suites of grasshopper species were adapted to changes in the local environment, with greatest diversity (Shannon H’) associated with elevated levels of bare ground and sparse vegetation cover. The greatest proportion of rare, endemic and sensitive grasshoppers (incl. Lentula minuta, Machaeridia conspersa and Qachasia fastigiata) was associated with a greater proportion of vegetation cover. The sensitivity of grasshopper assemblages to fire-grazing interactions, and the habitat requirements of different suites of species necessitates consideration of different types (fire and grazing) as well as levels of disturbances when adjusting management practices. We recommend that conservation of rare, endemic and sensitive grasshoppers should be prioritized, as these are most vulnerable to local extirpation.

Diversity of bumblebees, heteropteran\xa0bugs and grasshoppers maintained by both: abandonment and extensive management of mountain meadows in three regions across the Austrian and Swiss Alps

ContextAbandonment of extensively managed meadows is an ongoing global challenge in recent decades, particularly in mountain regions, and directly affects plant diversity. However, the extent to which plant diversity further affects associated insect pollinators or herbivores is little investigated.ObjectivesWe focused on the effects of abandonment of mountain meadows on species richness and assemblages of bumblebees, bugs and grasshoppers. Specifically, we investigated the influence of vegetation cover, flower cover, plant richness and surrounding landscape on the three insect groups.MethodsSpecies richness, abundance and species assemblages of bumblebees, bugs and grasshoppers were surveyed in one Swiss and two Austrian regions: three meadows which had been abandoned for 15–60 years, and three extensively managed meadows (mown once a year, no use of fertilizers). We surveyed bumblebees and bugs by sweep net, and grasshoppers using the time-effective soundscape approach.ResultsBumblebee species richness and abundance were significantly higher in managed meadows, whereas bug and grasshopper richness and abundance showed no differences between both management types. Managed and abandoned meadows harboured significantly different species assemblages of bugs and grasshoppers, but not of bumblebees. Increasing flower cover and plant richness increased bumblebee richness, but correlated negatively with richness of bugs. Surrounding open landscape positively affected bugs. Caelifera positively correlated with surrounding forest cover and negatively with vegetation cover. Vegetation cover positively affected Ensifera.ConclusionsAbandoned and extensively managed meadows are important habitat types for the conservation of the three insect groups, thus suggesting the maintenance of both habitat types within mountain landscapes.

Impacts of grazing intensity and increased precipitation on a grasshopper assemblage (Orthoptera: Acrididae) in a meadow steppe

1. Grasshoppers are dominant herbivores in grassland ecosystems, and many studies have examined how grazing by large herbivores and precipitation patterns individually influence the dynamics of grassland grasshopper assemblages, but their combined effects are largely unknown.2. In this study, grazing intensities (ungrazed, moderate, and heavy) were manipulated and precipitation (ambient and increased amount of rainfall) altered in a field experiment to test the effects of grazing and altered precipitation on a grasshopper community in a meadow steppe in northeastern China.3. It was found that grasshopper species richness did not change according to different grazing intensities under ambient precipitation, but was significantly higher (by 38.1%) in moderate grazing intensities under increased precipitation. Grasshopper abundance increased considerably with increasing grazing intensities in ambient precipitation treatments; however, grasshopper abundance in heavy grazing intensities was significantly lower (by 32.9%) than in the other two grazing intensities under increased precipitation. Moreover, the responses of grasshopper abundance to grazing under altered precipitation were species‐specific.4. Grazing effects on grasshopper species diversity were mediated through the species richness and biomass of grasses (food resources), but the effects on grasshopper abundance were mediated through plant height (vegetation structure) under altered precipitation.5. These results suggest that appropriate grazing by large herbivores would be considered as beneficial management practices for maintaining grasshopper diversity and abundance under conditions of increased precipitation in grassland ecosystems. Additionally, greater attention should be paid to the population dynamics of different grasshopper species to better understand the responses of grasslands to grazing and altered precipitation.

Extent to which an agricultural mosaic supports endemic species-rich grasshopper assemblages in the Cape Floristic Region biodiversity hotspot

The impact of expansion and intensification of agriculture on biodiversity requires quantification, especially in areas of exceptionally high biodiversity like the Cape Floristic Region (CFR). In the CFR, landscape mosaics consist of agriculture alongside Mediterranean-type fynbos scrubland natural vegetation rich in endemic insect species. However, little is known about how ground-dwelling insect herbivores utilize the various elements of the mosaic. We compared species richness, abundance, species composition, diversity and evenness of grasshoppers among 46 sites in four geographical areas in the CFR. We investigated three land-use types: fynbos (the historic condition as reference), vineyards and deciduous fruit orchards, the main production types in the region. Grasshopper abundance was significantly higher in vineyards than in fynbos or orchards. Species richness, diversity, and evenness were highest in fynbos followed by vineyards and then orchards. Orchards had no unique species, vineyards two, and fynbos 14 unique species. Nevertheless, there was overall high species similarity among all three land-use types, with high species assemblage similarities between vineyards and orchards. Species that preferred fynbos were mostly flightless and endemic to the CFR. We show that agricultural areas do not support the entire species assemblage of natural vegetation, although vineyards are more diverse than orchards, probably because of the presence of often grassy ground cover and an open canopy. Vineyards provide the greatest opportunity for improved harmony between production and biodiversity conservation through continuing to improve the ground cover quality and other farming practices. Fewer opportunities are provided by orchards in view of their closed canopy and absence of grassy ground cover (for generalist species) and fynbos plants (for endemic species). However, protected areas still remain vital for maintaining the full complement of species, especially flightless endemics.