Ecological and biodiversity gradients across alpine dry grassland habitats: implications for an endangered species

Dry grasslands are of great interest for nature conservation in Europe, because they have a central role in the conservation of numerous rare and endangered species. In this study carried out in the Brenta mountain group (Italian alps), we investigated the effect of environmental factors mainly controlled by topography, on the biodiversity trends across different dry grassland habitats where the threatened alpine stenoendemic Erysimum aurantiacum grows. Plant community data and ecological factors were analysed by means of a multi‐habitat CCA approach and by analysis of biodiversity gradients in 7 natural and semi‐natural habitats. We found that species turnover and biodiversity patterns vary as a function of multi‐factorial ecological gradients. For the single habitats, elevation gradient was the main factor explaining compositional variation, followed by inclination and proportion of exposed rock surface. Despite its endangered status, E. aurantiacum showed a relatively high degree of ecological plasticity across these semiarid grassland habitats that probably allows it to survive in different environments, including in some cases those impacted by human activities. This prompts for habitat‐ more than species‐level conservation actions. According to their characteristics and threats, habitat‐specific management practices are recommended for long term conservation of plant species communities in the different ecological niches.     

Plant cover associated with aboveground net primary productivity (ANPP) mediates insect community composition in steppes of Northwest China

Temperate steppe is one of the most important natural habitats for the conservation of arthropod and bird biodiversity across the Eurasian Tectonic Plate. Since 1950, fragmentation of the steppe habitat has caused a loss of biodiversity and degradation of the species communities found in natural steppe. Therefore, in this study, both plants and insects were sampled at 56 sites in the steppe biome of northwestern China to explore the effects of plant community on insect community composition and diversity. The insect community structure varied in the four different steppe types (meadow steppe, typical steppe, desert steppe, and steppe desert). Plant cover (diversity) was an important driving force, which could enhance number of families and abundance of an insect community. Aboveground net primary productivity and water content of plants had no significant effects on insect community, although the plant community as a whole did mediate insect composition and community structure. Future research should explore the ecological role of particular functional groups in plant and insect communities. Supplemental sowing to improve plant diversity in steppe habitat may be another strategy to enhance biodiversity and achieve sustainable management.     

Assessing the role of invasive weeds in the impact of successional habitats on the bird assemblage in overgrowing agriculture

Agricultural habitats are assumed to be biodiversity refuges. However, some studies treat agricultural land management as a cause of the biodiversity decline, to which habitat loss and heterogeneity may contribute. Between the crops, the successional habitats appear – ruderal plant communities and bush areas. Their influence on farmland biodiversity is unknown. This research assessed the impact of spatial relationships between agricultural areas, semi-natural meadows and successional habitats on the bird species richness, Shannon diversity index, and Faith’s phylogenetic diversity index. An additional habitat variable was the presence of weeds, i.e., invasive Caucasian hogweeds Heracleum sp., treated as crops in the past. The birds and habitats research was on 74 sites set in pairs (invaded vs control) in south-eastern Poland. Results showed that birds assembling in agricultural and semi-natural areas were more diverse and contained protected farmland species, while birds appearing in overgrown habitats (i.e., successional and invaded) were clumped with their habitat requirements. In the presence of plant invaders, ruderal habitats negatively affected the bird phylogenetic diversity index. In invaded sites, bush areas had no positive effects on the Shannon diversity index and species richness of birds, in contrast with control sites. The presented research suggests the need to re-evaluate the importance of successional non-crop habitats considered positive in agricultural landscapes if those habitats develop in areas with plant invasion.     

The species pool concept as a framework for studying patterns of plant diversity

Co‐existence theories fail to adequately explain observed community patterns (diversity and composition) because they mainly address local extinctions. For a more complete understanding, the regional processes responsible for species formation and geographic dispersal should also be considered. The species pool concept holds that local variation in community patterns is dependent primarily on the availability of species, which is driven by historical diversification and dispersal at continental and landscape scales. However, empirical evidence of historical effects is limited. This slow progress can be attributed to methodological difficulties in determining the characteristics of historical species pools and how they contributed to diversity patterns in contemporary landscapes. A role of landscape‐scale dispersal limitation in determining local community patterns has been demonstrated by numerous seed addition experiments. However, disentangling general patterns of dispersal limitation in communities still requires attention. Distinguishing habitat‐specific species pools can help to meet both applied and theoretical challenges. In conservation biology, the use of absolute richness may be uninformative because the size of species pools varies between habitats. For characterizing the dynamic state of individual communities, biodiversity relative to species pools provides a balanced way of assessing communities in different habitats. Information about species pools may also be useful when studying community assembly rules, because it enables a possible mechanism of trait convergence (habitat filtering) to be explicitly assessed. Empirical study of the role of historic effects and dispersal on local community patterns has often been restricted due to methodological difficulties in determining habitat‐specific species pools. However, accumulating distributional, ecological and phylogenetic information, as well as use of appropriate model systems (e.g. archipelagos with known biogeographic histories) will allow the species pool concept to be applied effectively in future research.     

Effects of landscape structure and land-use intensity on similarity of plant and animal communities

Aim Species richness in itself is not always sufficient to evaluate land management strategies for nature conservation. The exchange of species between local communities may be affected by landscape structure and land‐use intensity. Thus, species turnover, and its inverse, community similarity, may be useful measures of landscape integrity from a diversity perspective. Location A European transect from France to Estonia. Methods We measured the similarity of plant, bird, wild bee, true bug, carabid beetle, hoverfly and spider communities sampled along gradients in landscape composition (e.g. total availability of semi‐natural habitat), landscape configuration (e.g. fragmentation) and land‐use intensity (e.g. pesticide loads). Results Total availability of semi‐natural habitats had little effect on community similarity, except for bird communities, which were more homogeneous in more natural landscapes. Bee communities, in contrast, were less similar in landscapes with higher percentages of semi‐natural habitats. Increased landscape fragmentation decreased similarity of true bug communities, while plant communities showed a nonlinear, U‐shaped response. More intense land use, specifically increased pesticide burden, led to a homogenization of bee, bug and spider communities within sites. In these cases, habitat fragmentation interacted with pesticide load. Hoverfly and carabid beetle community similarity was differentially affected by higher pesticide levels: for carabid beetles similarity decreased, while for hoverflies we observed a U‐shaped relationship. Main conclusions Our study demonstrates the effects of landscape composition, configuration and land‐use intensity on the similarity of communities. It indicates reduced exchange of species between communities in landscapes dominated by agricultural activities. Taxonomic groups differed in their responses to environmental drivers and using but one group as an indicator for ‘biodiversity’ as such would thus not be advisable.     

Landscape moderation of biodiversity patterns and processes - eight hypotheses

Understanding how landscape characteristics affect biodiversity patterns and ecological processes at local and landscape scales is critical for mitigating effects of global environmental change. In this review, we use knowledge gained from human-modified landscapes to suggest eight hypotheses, which we hope will encourage more systematic research on the role of landscape composition and configuration in determining the structure of ecological communities, ecosystem functioning and services. We organize the eight hypotheses under four overarching themes. Section A: 'landscape moderation of biodiversity patterns' includes (1) the landscape species pool hypothesis-the size of the landscape-wide species pool moderates local (alpha) biodiversity, and (2) the dominance of beta diversity hypothesis-landscape-moderated dissimilarity of local communities determines landscape-wide biodiversity and overrides negative local effects of habitat fragmentation on biodiversity. Section B: 'landscape moderation of population dynamics' includes (3) the cross-habitat spillover hypothesis-landscape-moderated spillover of energy, resources and organisms across habitats, including between managed and natural ecosystems, influences landscape-wide community structure and associated processes and (4) the landscape-moderated concentration and dilution hypothesis-spatial and temporal changes in landscape composition can cause transient concentration or dilution of populations with functional consequences. Section C: 'landscape moderation of functional trait selection' includes (5) the landscape-moderated functional trait selection hypothesis-landscape moderation of species trait selection shapes the functional role and trajectory of community assembly, and (6) the landscape-moderated insurance hypothesis-landscape complexity provides spatial and temporal insurance, i.e. high resilience and stability of ecological processes in changing environments. Section D: 'landscape constraints on conservation management' includes (7) the intermediate landscape-complexity hypothesis-landscape-moderated effectiveness of local conservation management is highest in structurally simple, rather than in cleared (i.e. extremely simplified) or in complex landscapes, and (8) the landscape-moderated biodiversity versus ecosystem service management hypothesis-landscape-moderated biodiversity conservation to optimize functional diversity and related ecosystem services will not protect endangered species. Shifting our research focus from local to landscape-moderated effects on biodiversity will be critical to developing solutions for future biodiversity and ecosystem service management.     

Land‐use history,historical connectivity,and land management interact to determine longleaf pine woodland understory richness and composition

Restoration and management activities targeted at recovering biodiversity can lead to unexpected results. In part, this is due to a lack of understanding of how site‐level characteristics, landscape factors, and land‐use history interact with restoration and management practices to determine patterns of diversity. For plants, such factors may be particularly important since plant populations often exhibit lagged responses to habitat loss and degradation. Here, we assess the importance of site‐level, landscape, and historical effects for understory plant species richness and composition across a set of 40 longleaf pine Pinus palustris woodlands undergoing restoration for the federally endangered red‐cockaded woodpecker in the southeastern United States. Land‐use history had an overarching effect on richness and composition. Relative to historically forested sites, sites with agricultural histories (i.e. former pastures or cultivated fields) supported lower species richness and an altered species composition due to fewer upland longleaf pine woodland community members. Landscape effects did not influence the total number of species in either historically forested or post‐agricultural sites; however, understory species composition was affected by historical connectivity, but only for post‐agricultural sites. The influences of management and restoration activities were only apparent once land‐use history was accounted for. Prescribed burning and mechanical overstory thinning were key drivers of understory composition and promoted understory richness in post‐agricultural sites. In historically forested sites these activities had no impact on richness and only prescribed fire influenced composition. Our findings reveal complex interplays between site‐level, landscape, and historical effects, suggest fundamentally different controls over plant communities in longleaf pine woodlands with varying land‐use history, and underscore the importance of considering land‐use history and landscape effects during restoration.     

Environmental drivers of spider community composition at multiple scales along an urban gradient

Broad-scale modification of natural ecosystems associated with urbanisation often leads to localised extinctions and reduced species richness. Despite this, habitats within the urban matrix are still capable of supporting biodiversity to varying degrees. As species have different responses to anthropogenic habitat modification, the species composition of urban areas can depend greatly on the habitat characteristics of the local and surrounding areas. The aim of this study was to compare the community composition of spiders in private gardens, urban parks, patches of remnant vegetation and continuous bushland sites, so as to identify habitat variables associated with variation in spider populations along and within the urban gradient and matrix. Overall spider abundances and richness were highest in remnant vegetation patches and were associated with increased vegetation cover at microhabitat and landscape-scales. While gardens were not as diverse as remnant patches, they did support a surprisingly high diversity of spiders. We also found that species composition differed significantly between gardens and other urban green spaces. Higher richness within gardens was also associated with greater vegetation cover, indicating the importance of private management decisions on local biodiversity. Differences in community composition between land-use types were driven by a small number of urban-tolerant species, and spider guilds showed different responses to habitat traits such as vegetation cover and human population densities. This study demonstrates that urban land-uses support unique spider communities and that maintaining vegetation cover within the urban matrix is essential in order to support diverse spider communities in cities.     

The early effects of afforestation on biodiversity of grasslands in Ireland

The target rate of afforestation in Ireland over the next 30 years is 20,000 ha per year, which would result in an increase of the forest cover from the current 10% to 17%. In order to promote sustainable forest management practices, it is essential to know the composition and conservation value of habitats where afforestation is planned and the effects of subsequent planting upon biodiversity. The objectives of this study were to investigate changes in vegetation composition and diversity of grasslands 5 years after afforestation with Sitka spruce (Picea sitchensis) and determine the primary ecological and management factors responsible for these changes. Species cover, environmental and management data were collected from 16 afforested and unplanted improved and wet grassland site pairs in Ireland. Our results indicate that 5 years after tree planting, there were significant changes in richness, composition, and abundance of species. Competitive and vigorous grasses were more abundant in planted than in unplanted sites, as were generalist species found in both open and wooded habitats, while small-stature shade-sensitive species were less abundant. Vascular plant species richness and Shannon’s diversity index were higher in unplanted wet grassland, than in the planted sites. Bryophyte species richness was higher in planted improved grassland than in unplanted sites. The differences were primarily the result of the exclusion of grazing, ground preparation, changes in nutrient management and drainage for afforestation. Drainage ditches provided a temporary habitat for less competitive species, but the overall effect of drainage was to reduce the diversity of species dependent on wet conditions. Variance partitioning showed differences in the relative influences of environmental and management variables on biodiversity in the two habitats, probably due to the greater pre-afforestation grazing pressure and fertilisation levels in improved grasslands. The differences in biodiversity between planted and unplanted grasslands indicate that afforestation represents a threat to semi-natural habitats where distinctive and highly localised plant communities could potentially occur.     

Habitat associations of epigeal spiders in upland calcareous grassland landscapes: the importance for conservation

Upland calcareous grassland landscapes are typically comprised of a matrix of calcareous grassland, acid grassland and limestone heath plant communities. This matrix of habitats is produced by a combination of underlying geology, climate and management. These landscapes are typically managed through grazing, with management targeted to maintain particular plant communities in the calcareous grassland habitat, whilst patches of acid grassland and limestone heath are not targeted by conservation management. The biodiversity value of acid grassland and limestone heath patches within the calcareous grassland matrix are unknown. This study provides the first assessment of their biodiversity value by examining aspects of epigeal spider diversity supported by these non-target habitat patches in comparison to calcareous grassland. Spiders were sampled in each habitat from April to August 2014 using pitfall traps across three upland regions in Great Britain. Spider species assemblages were distinct between limestone heath and both grassland types. Distinction in species assemblages are likely due to differences in vegetation structure and microclimate, e.g., humidity, degree of shade. Each habitat type supported several rare species (e.g., Jacksonella falconeri, Agyneta subtilis) revealing the contribution to spider fauna. The distinct spider species assemblage and presence of rare species in limestone heath patches demonstrate their importance in the upland calcareous grassland matrix. This study highlights the value of monitoring biodiversity in non-target habitats within a habitat matrix alongside those that are actively targeted by management.     

The impact of recreational use and access on biotic and abiotic disturbances on areas protected by local communities and a state conservation agency

Local communities often conserve nearby natural areas to support recreational activities and other benefits these areas provide. Areas protected by local communities could contribute to wider efforts to achieve large-scale conservation goals, such as biodiversity protection, provided the ecological conditions on-site are compatible with achieving these goals. To explore the potential contribution of locally established protected areas, we focus on areas protected by local communities in California, USA, using ballot initiatives, a form of direct democracy. We compare the ecological condition of wooded habitat on protected areas funded by local communities through the ballot box to that of similar habitats on protected areas funded by a state conservation agency. As an indicator of ecological condition, we focus on coverage by exotic plant species. We examine whether protected area characteristics or aspects of human-mediated onsite disturbance related to recreational use explain exotic plant cover found on each type of protected area. Exotic plant cover did not differ between areas protected by local communities and those protected by our larger scale conservation actor. Instead, elevation was the best predictor of exotic plant cover. Our results suggest protected areas established by local communities may be in no worse a condition than those established by a state public agency and warrant inclusion when tracking progress towards large-scale conservation goals for protected areas.     

Management of invasive plants through ecological resistance

Despite debates on the real impact of plant invasion on native biodiversity, there remain many situations where exotic invasive plants must be managed and habitats restored. Restoration practices that build on plant community assembly principles could be useful to delay or prevent re-invasion after control, but there are still few syntheses of the biodiversity theory, ecological mechanisms and experimental evidence relevant to invasive plant management, possibly delaying applications. To provide such a synthesis, we review current knowledge on three key determinants of invasion success: biotic resistance, abiotic constraints, and propagule pressure. We elaborate on the ecological mechanisms at play for each determinant and emphasize, using case studies, their relevance for invasive plant management and ecological restoration. We find evidence that restoring a plant cover can enhance invasion resistance, but the challenge for both research and field applications is to understand how multiple determinants interact in relation to species traits in the fields. Failure to recognize these interactions and their effect on community assembly processes may explain some of the mixed species responses observed. While we need control and restoration case studies with local species at different sites, the development of a coherent, dynamic and adaptive framework around biotic/ecological resistance will have to go beyond the idiosyncrasy of the many species and systems being tested. Emphasizing the functional diversity of the restored community seems a promising approach when facing potentially multiple invaders and/or fluctuating abiotic conditions.     

Does habitat loss affect the communities of plants and insects equally in plant–pollinator interactions? Preliminary findings

Habitat loss is a major threat to biodiversity and ecosystem function. As habitats are lost, one factor affecting their community structures is the niche-width demand of species, which ranges from specialist to generalist. This study focused on specialist and generalist species in plant–pollinator interactions and tested the hypothesis that plant and pollinator communities become more generalized as habitat loss increases. The study was made in seven selected sites in southern Ontario, Canada, at the level of landscape that is characterized by distributed forests within intensively managed agricultural fields. We quantified both the degree of habitat loss and the degree of specialization/generalization for each of the plant and insect communities using a sampling method of hexagonal transects. Regression analysis indicated a significant relationship between the increase of habitat loss and the shift to generalization in insect, but not in plant, communities. Our results suggest that, in plant–pollinator interactions, insect communities are more sensitive and/or quicker than plant communities to respond to the effects of habitat loss.     

Are restricted species checklists or ant communities useful for assessing plant community composition and biodiversity in grazed pastures?

Semi-natural grasslands in Sweden are species-rich, and their natural values are strongly dependent on continuous management, mainly by grazing. However, the large heterogeneity in vegetation within and between grassland sites must be taken into account when designing management and preservation schemes, calling for precise field monitoring and assessment of habitat type and land use history. We have evaluated different surrogate measures to assess community composition and biodiversity of the most common vegetation types in grazed semi-natural pastures. We compared the complete plant community, two reduced checklists intended for quick surveys of the plant community, and the ant community. The results suggest that the taxonomic resolution in a plant inventory is important for both biodiversity assessment and recognition of vegetation types. The extent of a reduced species checklist was of greater importance than its quality for describing the plant community. Reduced checklists should only be used if they comprise species with known affinity to the studied vegetation types. We also found that plants and ants experience grazed semi-natural grasslands in different ways. Ant communities did not resemble the communities deduced from plant inventories, or vegetation types recognised by field staff.     

Soil and bark biodiversity forms discrete islands between vineyards that are not affected by distance or management regime

Within geographic regions, the existing data suggest that physical habitat (bark, soil, etc.) is the strongest factor determining agroecosystem microbial community assemblage, followed by geographic location (site), and then management regime (organic, conventional, etc.). The data also suggest community similarities decay with increasing geographic distance. However, integrated hypotheses for these observations have not been developed. We formalized and tested such hypotheses by sequencing 3.8 million bacterial 16S, fungal ITS2 and non-fungal eukaryotic COI barcodes deriving from 108 samples across two habitats (soil and bark) from six vineyards sites under conventional or conservation management. We found both habitat and site significantly affected community assemblage, with habitat the stronger for bacteria only, but there was no effect of management. There was no evidence for community similarity distance–decay within sites within each habitat. While communities significantly differed between vineyard sites, there was no evidence for between site community similarity distance–decay apart from bark bacterial communities, and no correlations with soil and bark pH apart from soil bacterial communities. Thus, within habitats, vineyard sites represent discrete biodiversity islands, and while bacterial, fungal and non-fungal eukaryotic biodiversity mostly differs between sites, the distance by which they are separated does not define how different they are.     

Restore it,and they will come: trap-nesting bee and wasp communities (Hymenoptera: Aculeata) are recovered by restoration of riparian forests

Riparian forests have been greatly affected by anthropogenic actions with formerly continuous riparian forests being slowly converted into small and isolated patches. Riparian forests are extremely important habitats for many groups of insects, including bees and wasps, because they are sources of shelter and food for them and their offspring. There is a growing body of evidence of success in the restoration of riparian forest plant communities; however, little research has been done on the associated invertebrate communities. We test whether restoring plant communities is sufficient for restoring the taxonomic composition of trap-nesting bees and wasps and which functional traits are favored in different sites. We predict that species richness, abundance, and community composition of trap-nesting bees and wasps of riparian sites undergoing restoration will converge on the “target” of a reference site with increasing time, since restoration increases habitat complexity. We also predict that the width of restored patches will also influence the species richness, abundance and community composition of trap-nesting bees and wasps. Bee richness and abundance, and wasp richness, were strongly related to fragment width, but not to age since restoration. Our results indicate that although restored sites are relatively small and scattered in a fragmented landscape, they provide suitable habitat for re-colonization by community assemblages of trap-nesting bees and wasps and the traits selected captured the responses to the habitat restoration. Hence, restored riparian areas can be considered important habitats for invertebrates, thus contributing to an increase in local biodiversity and, possibly, the restoration of some of the ecosystem services they originally provided.     

Future ocean climate homogenizes communities across habitats through diversity loss and rise of generalist species

Predictions of the effects of global change on ecological communities are largely based on single habitats. Yet in nature, habitats are interconnected through the exchange of energy and organisms, and the responses of local communities may not extend to emerging community networks (i.e., metacommunities). Using large mesocosms and meiofauna communities as a model system, we investigated the interactive effects of ocean warming and acidification on the structure of marine metacommunities from three shallow‐water habitats: sandy soft‐bottoms, marine vegetation, and rocky reef substrates. Primary producers and detritus—key food sources for meiofauna—increased in biomass under the combined effect of temperature and acidification. The enhanced bottom‐up forcing boosted nematode densities but impoverished the functional and trophic diversity of nematode metacommunities. The combined climate stressors further homogenized meiofauna communities across habitats. Under present‐day conditions metacommunities were structured by habitat type, but under future conditions they showed an unstructured random pattern with fast‐growing generalist species dominating the communities of all habitats. Homogenization was likely driven by local species extinctions, reducing interspecific competition that otherwise could have prevented single species from dominating multiple niches. Our findings reveal that climate change may simplify metacommunity structure and prompt biodiversity loss, which may affect the biological organization and resilience of marine communities.     

Metacommunities of spiders in grassland habitat fragments of an agricultural landscape

Arthropod communities in fragmented agricultural landscapes depend on local processes and the interactions between communities in the habitat islands. We aimed to study metacommunity structure of spiders, a group that is known for high dispersal power, local niche partitioning and for engaging in species interactions. While living in fragmented habitats could lead to nestedness, other ecological traits of spiders might equally lead to patterns dominated either by species interactions or habitat filtering. We asked, which community pattern will prevail in a typical agricultural landscape with isolated patches of semi-natural habitats. Such a situation was studied by sampling spiders in 28 grassland locations in a Hungarian agricultural landscape. We used the elements of metacommunity structure (EMS) framework to distinguish between alternative patterns that reveal community organization. The EMS analysis indicated coherent species ranges, high turnover and boundary clumping, suggesting Clementsian community organization. The greatest variation in species composition was explained by local habitat characteristics, indicating habitat filtering. The influence of dispersal could be detected by the significant effect of landscape composition, which was strongest at 500 m. We conclude that dispersal allows spiders to respond coherently to the environment, creating similar communities in similar habitats. Consistent habitat differences, such as species rich versus species poor vegetation, lead to recognisably different, recurrent communities. These characteristics make spiders a predictable and diverse source of natural enemies in agricultural landscapes. Sensitivity to habitat composition at medium distances warns us that landscape homogenization may alter these metacommunity processes.     

片段化森林群落构建的生态过程及其检验方法

鉴于全球森林均呈现片段化(破碎化)的分布状态, 理解片段化森林群落构建的过程很有必要。该文通过综述群落构建的主要生态过程如生态漂变、扩散、选择和物种形成等在片段化森林群落构建中的相对作用, 发现因片段化森林形成方式的不同, 重构群落(片段化生境中通过次生演替重新形成的森林群落)和解构群落(原有森林被片段化后形成的森林群落)在不同演替阶段所受到的主要生态过程的相对作用有所不同。虽然利用基于群落内物种分布格局推测构建过程(如物种多度分布、零模型结合β多样性的方法、功能特征的收敛和发散等)、人工控制实验、群落结构动态分析等方法对片段化森林中群落构建的过程进行了有效的检验, 但是针对片段化森林群落构建过程的实验性研究仍然不足。未来有待在理论模型、群落构建过程的检验以及理论与物种保护相结合等方面继续开展深入的研究。     

Urban greenspace composition and landscape context influence natural enemy community composition and function

Conservation research has historically been aimed at preserving high value natural habitats, but urbanization and its associated impacts have prompted broader mandates that include the preservation and promotion of biodiversity in cities. Current efforts within urban landscapes aim to support biodiversity and diverse ecosystem services such as storm water management, sustainable food production, and toxin remediation. Arthropod natural enemies provide biocontrol services important for the ecosystem management of urban greenspaces. Establishing habitat for these and other beneficial arthropods is a growing area of urban conservation. Habitat design, resource inputs, management, and abiotic conditions shape the value of greenspace habitats for arthropods. In general, larger patches with diverse plant communities support a greater abundance and diversity of natural enemies and biocontrol services, yet opposing patterns or no effects have also been documented. The surrounding landscape is likely a contributor to this variation in natural enemy response to patch-scale habitat design and management. Looking across rural–urban landscape gradients, natural enemy communities shift toward dominance by habitat generalists and disturbance tolerant species in urban areas compared to rural or natural communities. These changes have been linked to variation in habitat fragmentation, plant productivity and management intensity. In landscape-scale studies focusing solely within cities, variables such as impervious surface area and greenspace connectivity affect the community assembly of natural enemies within a patch. Given these findings, a greater mechanistic understanding of how both the composition and spatial context of urban greenspaces influence natural enemy biodiversity–biocontrol relationships is needed to advance conservation planning and implementation.