Species-rich Plant Communities Research Articles

The Relationship of Dominance and Evenness with Productivity and Species Richness in Plant Communities with Different Organization Models

The relationship between dominance and evenness in plant communities organized according to different models—competitive (alpine, subalpine, and low-mountain grasslands), stress-tolerant (alpine heaths and scrubs, subalpine fens, steppes, the forest herbaceous layer), and ruderal—has been analyzed in the Western Caucasus and Ciscaucasia. No correlation between evenness (dominance) and productivity has been revealed in communities of any type. The correlation between dominance and species richness is negative and, in most cases, linear, being stronger in competitive and ruderal than in stress-tolerant cenoses. The correlation between evenness and species richness in grassland communities (the competitive model) is strong, positive, and linear, while this correlation in ruderal and stress-tolerant communities is weak or absent.

Epigean communities of harvestmen (Opiliones) in Pannonian Basin floodplain forests: an interaction with environmental parameters

During the years 2015–2016, we studied the fauna of epigeon in eight similar habitats in Slovakia and Serbia. The study material of Opiliones was obtained by a pitfall trap method. We focused on the comparison of the incidence of harvestmen in floodplain forests and ecotones alongside the Danube River in Slovakia and along the Tisa and Begej River in Serbia. We examined their dependence on anthropogenic impact (frequency of visits), cover of vegetation layers (herbs, shrubs and trees), plant diversity of vegetation layers, area of forest stands, distance to the forest edge, circumference of forest stands, age of forest stands, thickness of litter layer and physico-chemical properties of soil and litter (pH, conductivity, P, N, C, H). Total epigeic activity of harvestman showed significant positive relationship with proportion of N in litter. Community equitability was positively related with species richness of plant communities in shrub layer and negatively related with H content of soil. We did not find any significant correlations between diversity of harvestman communities and measured environmental characteristics.

Intensity-dependent impact of sport climbing on vascular plants and land snails on limestone cliffs

Limestone cliffs in the Jura Mountains harbour species-rich plant and animal communities including rare species. Sport climbing has recently increased in popularity in this habitat and several studies have reported damage to cliff biodiversity. However, so far how damage levels vary with climbing intensity has not been investigated. We evaluated the effects of climbing intensity on the diversity of vascular plants and land snails in 35 limestone cliff sectors in the Northern Swiss Jura Mountains. Mixed-effects models were used to examine whether species richness of plants and land snails differ between cliff sectors with low and high climbing intensity and unclimbed cliff sectors (controls) taking into account potential influences of cliff characteristics (aspect, cliff height, rock microtopography). At the cliff base, the best fit model revealed that plant species richness was affected by climbing intensity and cliff aspect. Plant species richness was reduced by 12.2% and 13.1%, respectively, in cliff sectors with low and high climbing intensity compared to unclimbed cliff sectors. On the cliff face, plant species richness was only influenced by climbing intensity (species richness reduction by 24.3% and 28.1%). Combining data from cliff base, face and plateau, the best fit model revealed that land snail species richness was only affected by climbing intensity (species richness reduction by 2.0% and 13.7%). In both organism groups, species composition was increasingly altered by increasing climbing intensity. Our study provides evidence that even low climbing intensity reduces cliff biodiversity and that damage becomes more pronounced with increasing climbing intensity.

FQA: A method for floristic quality assessment based on conservatism of plant species

FQA, which uses the conservatism of plant species for particular habitats and the species richness of plant communities, is a rapid method for the assessment of habitat quality. This method is based on species composition of quadrats and coefficients of conservatism for species which assigned by experts. Floristic Quality Index (FQI) that reflects vegetation integrity and degradation of a site can be calculated by a simple formula and be used for space-time comparison of habitat quality. It has been widely used in more than ten countries including the United States and Canada. This paper presented the principle, calculation formulas and application cases of this method, with the aim to provide a simple, repeatable and comparable method to assess habitat quality for ecological managers and researchers.

Predictive model for meadow owners’ participation in agri-environmental climate schemes in Natura 2000 areas

European semi-natural grasslands maintained through traditional practices are among the most species-rich plant communities within the present-day rural landscape. However, land use change has caused a drastic decline in grassland area. In European agricultural policy, agri-environmental schemes (AES) have been introduced to preserve, enhance and restore biodiversity on European farmland. Goričko Landscape Park (GLP) in Slovenia is Natura 2000 area with the aim to preserve traditional and extensive small-scale farming. Measures to encourage proper management of extensively used meadows in GLP were carried out within the Agricultural Environmental Climate Scheme (AECS). The aims of this research were to identify key factors that might affect an owner’s decision to adopt AECS. The data were collected with online and paper versions of a survey completed by 198 meadow owners between April 2015 and April 2016. Owners reported that 41.3% of a total of 368 meadows were involved in AECS. In year 2015, there were 156 officially registered Agricultural Economies from GLP. With 53 analysed meadows (34%), involved in AECS, the confidence level was 95% and the confidence interval was 11. Based on binominal logistic regression factors having a positive significant influence on participation in AECS were, as follows: large meadow area, higher education level and higher knowledge about goals of Natura 2000. Factors that do not statistically significantly contribute to participation in AECS are meadow type, income, age, gender, environmental values, management independence, subsidy rate and knowledge about AECS. Factor having a negative significant influence on participation in AECS was subsidy procedure. To increase the number of participants in AECS and therefore encourage proper management of extensively used meadows, young owners should be encouraged to participate in AECS, because older owners who had completed secondary school were more likely to participate in AECS. There is also a lack of female owners participating in AECS because of their lack of skills and knowledge about AECS. Additionally the subsidy procedure for joining AECS should be simplified. Owners should get more information about AECS and available options and why it even matters to implement AECS. With knowledge about the factors that influence participation in AECS, we can positively affect farmer behaviour, thereby increasing the number of participants in AECS.

Global environmental change effects on plant community composition trajectories depend upon management legacies.

The contemporary state of functional traits and species richness in plant communities depends on legacy effects of past disturbances. Whether temporal responses of community properties to current environmental changes are altered by such legacies is, however, unknown. We expect global environmental changes to interact with land-use legacies given different community trajectories initiated by prior management, and subsequent responses to altered resources and conditions. We tested this expectation for species richness and functional traits using 1814 survey-resurvey plot pairs of understorey communities from 40 European temperate forest datasets, syntheses of management transitions since the year 1800, and a trait database. We also examined how plant community indicators of resources and conditions changed in response to management legacies and environmental change. Community trajectories were clearly influenced by interactions between management legacies from over 200years ago and environmental change. Importantly, higher rates of nitrogen deposition led to increased species richness and plant height in forests managed less intensively in 1800 (i.e., high forests), and to decreases in forests with a more intensive historical management in 1800 (i.e., coppiced forests). There was evidence that these declines in community variables in formerly coppiced forests were ameliorated by increased rates of temperature change between surveys. Responses were generally apparent regardless of sites' contemporary management classifications, although sometimes the management transition itself, rather than historic or contemporary management types, better explained understorey responses. Main effects of environmental change were rare, although higher rates of precipitation change increased plant height, accompanied by increases in fertility indicator values. Analysis of indicator values suggested the importance of directly characterising resources and conditions to better understand legacy and environmental change effects. Accounting for legacies of past disturbance can reconcile contradictory literature results and appears crucial to anticipating future responses to global environmental change.

Allelopathic invasive tree (Rhamnus cathartica) alters native plant communities

Many plants release allelopathic chemicals that can inhibit germination, growth, and/or survival in neighboring plants. These impacts appear magnified with the invasion of some non-native plants which may produce allelochemicals against which native fauna have not co-evolved resistance. Our objective was to examine the potential allelopathic impact of an invasive non-native shrub/tree on multiple plant species using field observation and experimental allelopathy studies. We surveyed and collected an invasive, non-native tree/shrub (Rhamnus cathartica) at Tifft Nature Preserve (a 107-ha urban natural area near Lake Erie in Buffalo, NY). We also surveyed understory plant communities in the urban forest to examine correlations between R. cathartica abundance and local plant community abundance and richness. We then used experimental mesocosms to test if patterns observed in the field could be explained by adding increased dosages of R. cathartica to soils containing five plant species, including native and non-native woody and herbaceous species. In the highly invaded urban forest, we found that herbaceous cover, shrubs and woody seedlings negatively covaried with R. cathartica basal area and seedlings density. In the mesocosm experiments, R. cathartica resulted in significant decreases in plant community species richness, abundance, and shifted biomass allocation from roots. Our results provide evidence that R. cathartica is highly allelopathic in its invaded range, that R. cathartica roots have an allelopathic effect and that some plant species appear immune. We suggest that these effects may explain the plant’s ability to form dense monocultures and resist competitors, as well as shift community composition with species-specific impacts.

Factors Affecting Composition of Gravel Bar Vegetation in Middle Reach of a Lowland River

ABSTRACT In this study, we investigated plant communities in relation to site-specific morphological properties and sediment structure on gravel bars along the middle Drava River in Slovenia. We sampled 143 plots of 5 × 5 m using species cover-abundance estimates. In addition, we considered the following habitat physical variables: elevation above the water line, texture of the substrate (silt, sand, gravel content) and bar age. Based on TWINSPAN method, we distinguished four vegetation types: (G1) xerophilic and thermophilic ruderal stage; (G2) stage with sparse and herb-rich ruderal vegetation with species of semi-dry grasslands; (G3) initial vegetation stage of frequently disturbed mesotrophic and eutrophic sites and (G4) tall-willow stage. The most important factors determining a bar's vegetation were elevation and gravel content. Our study shows that gravel bars of the middle Drava river system form a suitable habitats for species-rich plant communities. Their diversity is a function of high spatial ...

Research Article: Relationships between plant community species richness, remnant area, and invasive leafy spurge cover in southeastern Minnesota bluff prairie habitats

Abstract Bluff prairies are extreme habitats centered on southwestern facing bluffs along major rivers in the driftless area of the upper Midwest. Characterized by steep slopes, thin soils, and intense exposure to sun and wind, bluff prairies harbor a much warmer, drier microclimate than is found elsewhere in the region. Such harsh conditions help preserve bluff prairie habitat for unique communities of plants and animals. However, like many prairie habitats, bluff prairies are shrinking in size and experiencing fragmentation, resulting in smaller prairie remnants rather than larger, intact prairies. This shrinking and fragmentation is likely a consequence of non-prairie and/or non-native plants encroaching from the edges. One prominent introduced invasive species, leafy spurge (Euphorbia esula), has the ability to spread quickly and displace native plants. During the summer of 2012, the native flowering plant communities (excluding grasses, rushes, and sedges), prairie remnant sizes, and invasive leafy s...

Community-level spatial structure supports a model of stochastic geometry in species-rich shrublands

In some ecosystems a small suite of species can determine community-level patterns of species richness by acting as either ‘accumulators’ or ‘repellers’; that is, the richness of the immediate neighbourhood of such species departs from that expected on the basis of a given null model. Using the individual species-area approach, we evaluated community-level spatial pattern in four species-rich shrublands (two 40 × 40 m and two 30 × 30 m plots) by assessing the frequency of accumulator and repeller species and whether any such species were associated with specific life-history characteristics. Few species departed from the expectations of the null spatial model that we used, although, at three of the four sites, accumulators were more common than repellers. Departures from the null model we assessed were most prevalent within just 1 m of focal individuals and were not consistently associated with specific life-history traits. Model-based clustering suggests that there are distinct sub-communities in each of the four communities, but while internally spatially cohesive, these sub-communities intermingle and their membership is not predictable from the life-history traits of their constituent species. Comparable analyses in other species-rich systems have also detected a similar absence of spatial interactions. The disturbance regime in the shrubland communities we consider is markedly different from those in the forest ecosystems where previous studies have been concentrated (recurrent fire versus infrequent gap-phase dynamics) and resources are more limiting. Thus, our results provide further support for the generality of a model of stochastic geometry, likely underpinned by stochastic dilution effects, in species-rich plant communities.

Linking plant communities on land and at sea: The effects of Posidonia oceanica wrack on the structure of dune vegetation

Although terrestrial and marine ecosystems are often perceived as clearly distinct, in coastal areas biological communities on land and at sea are in fact intimately linked. One way in which terrestrial and marine systems interact is through the accumulation of seagrass wrack on beaches, which plays an important role as a nutrient input in coastal dune food webs. Here we test whether accumulated beach-cast wrack also influences the structure and diversity of coastal dune plant communities. Relying on a database of 572 vegetation surveys distributed across the island of Sardinia, we used mixed-effects models to compare the vegetation cover and species richness of plant communities exposed to different amounts of Posidonia oceanica beach-cast wrack. We found that beaches which receive high amounts of P. oceanica wrack have considerably greater vegetation cover (10% on average) than those with fewer deposits. The positive relationship between beach-cast wrack and vegetation cover was especially strong in nearshore plant communities, becoming progressively weaker along the habitat zonation. A similar pattern was found for species richness: beaches with high levels of accumulated wrack had more diverse drift line and foredune plant communities, while habitats further away from the shoreline were unaffected. Our study is the first to present evidence suggesting that activities which reduce wrack accumulation on beaches – either through direct removal of deposits or by causing P. oceanica seabeds to decline – can have effects on both the structure and diversity of coastal dune plant communities. Effective management of Mediterranean coastal dune ecosystems will require developing clear strategies for the removal and relocation of accumulated beach-cast wrack.

Structure, Variation, and Co-occurrence of Soil Microbial Communities in Abandoned Sites of a Rare Earth Elements Mine.

Mining activity for rare earth elements (REEs) has caused serious environmental pollution, particularly for soil ecosystems. However, the effects of REEs on soil microbiota are still poorly understood. In this study, soils were collected from abandoned sites of a REEs mine, and the structure, diversity, and co-occurrence patterns of soil microbiota were evaluated by Illumina high-throughput sequencing targeting 16S rRNA genes. Although microbiota developed significantly along with the natural restoration, the microbial structure on the site abandoned for 10 years still significantly differed from that on the unmined site. Potential plant growth promoting bacteria (PGPB) were identified by comparing 16S sequences against a self-constructed PGPB database via BLAST, and it was found that siderophore-producing and phosphorus-solubilizing bacteria were more abundant in the studied soils than in reference soils. Canonical correspondence analysis indicated that species richness of plant community was the prime factor affecting microbial structure, followed by limiting nutrients (total carbon and total nitrogen) and REEs content. Further co-occurring network analysis revealed nonrandom assembly patterns of microbiota in the studied soils. These results increase our understanding of microbial variation and assembly pattern during natural restoration in REE contaminated soils.

Species-specific effects of leaf litter on seedling emergence and growth of the invasive Flaveria bidentis and its co-occurring native species: a common garden test

The amount of litter and its type can affect seedling establishment and species richness in plant communities. However, little is known about the species-specific effects of litter, especially in the presence of a competitor. We conducted a common garden test to examine the combined effects of competition and plant litter from conspecific versus heterospecific species on the emergence and early growth of the invasive plant Flaveria bidentis and the co-occurring native plant Amaranthus retroflexus. The litter of native species reduced the rate of seedling emergence of F. bidentis; this effect was stronger in the presence of a competitor. Litter addition reduced the seedling emergence rate of A. retroflexus, but had a neutral to positive effect on its early growth, indicating a clear species-specific pattern. Litter addition, combined with interspecific competition, facilitated growth of A. retroflexus; this species seemed to perform better in changing soil conditions than did F. bidentis. Consequently, a habitat-specific adaptation might be involved in this interspecific plant–soil feedback. Our results contribute our understanding of how to suppress F. bidentis in disturbed sites without herbicide application. Manipulating litter cover could be used to manage this invader; such addition would either affect emergence or the belowground competition for soil resources.

Roles of Arbuscular Mycorrhizal Fungi and Soil Abiotic Conditions in the Establishment of a Dry Grassland Community.

BackgroundThe importance of soil biota in the composition of mature plant communities is commonly acknowledged. In contrast, the role of soil biota in the early establishment of new plant communities and their relative importance for soil abiotic conditions are still poorly understood.Aims and MethodsThe aim of this study was to understand the effects of soil origin and soil fungal communities on the composition of a newly established dry grassland plant community. We used soil from two different origins (dry grassland and abandoned field) with different pH and nutrient and mineral content. Grassland microcosms were established by sowing seeds of 54 species of dry grassland plants into the studied soils. To suppress soil fungi, half of the pots were regularly treated with fungicide. In this way, we studied the independent and combined effects of soil origin and soil community on the establishment of dry grassland communities.Key ResultsThe effect of suppressing the soil fungal community on the richness and composition of the plant communities was much stronger than the effect of soil origin. Contrary to our expectations, the effects of these two factors were largely additive, indicating the same degree of importance of soil fungal communities in the establishment of species-rich plant communities in the soils from both origins. The negative effect of suppressing soil fungi on species richness, however, occurred later in the soil from the abandoned field than in the soil from the grassland. This result likely occurred because the negative effects of the suppression of fungi in the field soil were caused mainly by changes in plant community composition and increased competition. In contrast, in the grassland soil, the absence of soil fungi was limiting for plants already at the early stages of their establishment, i.e., in the phases of germination and early recruitment. While fungicide affects not only arbuscular mycorrhizal fungi but also other biota, our data indicate that changes in the AMF communities are the most likely drivers of the observed changes. The effects of other soil biota, however, cannot be fully excluded.ConclusionsThese results suggest that the availability of soil fungi may not be the most important limiting factor for the establishment of grassland species in abandoned fields if we manage to reduce the intensity of competition at these sites e.g., by mowing or grazing.

Impact of pollen resources drift on common bumblebees in NW Europe.

Several bee species are experiencing significant population declines. As bees exclusively rely on pollen for development and survival, such declines could be partly related to changes in their host plant abundance and quality. Here, we investigate whether generalist bumblebee species, with stable population trends over the past years, adapted their diets in response to changes in the distribution and chemical quality of their pollen resources. We selected five common species of bumblebee in NW Europe for which we had a precise description of their pollen diet through two time periods ('prior to 1950' and '2004-2005').For each species, we assessed whether the shift in their pollen diet was related with the changes in the suitable area of their pollen resources. Concurrently, we evaluated whether the chemical composition of pollen resources changed over time and experimentally tested the impact of new major pollen species on the development of B. terrestris microcolonies. Only one species (i.e. B. lapidarius) significantly included more pollen from resources whose suitable area expanded. This opportunist pattern could partly explain the expansion of B. lapidarius in Europe. Regarding the temporal variation in the chemical composition of the pollen diet, total and essential amino acid contents did not differ significantly between the two time periods while we found significant differences among plant species. This result is driven by the great diversity of resources used by bumblebee species in both periods. Our bioassay revealed that the shift to new major pollen resources allowed microcolonies to develop, bringing new evidence on the opportunist feature of bumblebee in their diets. Overall, this study shows that the response to pollen resource drift varies among closely related pollinators, and a species-rich plant community ensures generalist species to select a nutrient-rich pollen diet.

Growth–survival trade-off in shrub saplings from Neotropical mountain grasslands

The growth–survival trade-off plays a central role in the coexistence of species-rich plant communities. While recurrently described in forest tree communities primarily limited by light availability, this trade-off is still poorly documented in grassland and savanna vegetation. In this comparative study we planted in a quartzitic degraded site eight-month-old saplings of eleven shrub species native from constrained mountain grassland (Brazilian rupestrian grassland). We measured the relative growth rate (RGR) during a 30-week time interval, leaf water potential under dry and wet conditions, and related these traits to the species survival. The interspecific comparison between the saplings performance clearly showed the classic growth–survival trade-off. The RGR expressed in stem diameter and aboveground biomass explained respectively 62% and 40% of the variation in saplings' survival one year after planting, and respectively 65% and 44% of the variation in survival 4.5years after planting. This trade-off was not related to either leaf water potential or final size in aboveground biomass and basal stem diameter. Our results corroborate the view that the growth–survival trade-off is universally applicable, even in non-forest communities such as grasslands and savannas subjected to severe nutritional deficiency, pronounced seasonal drought, and high light incidence. The environmental differences in micro-habitats that compose rupestrian grasslands should distinctly favour species with contrasting strategies of growth and survival, thus contributing to niche partitioning and coexistence in this species-rich ecosystem.

A probability distribution model of small -scale species richness in plant communities

We devised a probability distribution model that best expressed species richness per quadrat in grassland communities, and clarified the mechanism by which the mean richness per quadrat was always larger than the variance among quadrats. Our model will aid in the understanding of community structures, and allow comparisons among different communities. The model was constructed based on relatively simple theoretical assumptions about the mechanisms in play in target communities. We assumed in the model that the number of species occurring in an actual quadrat, j, is the sum of “the fundamental number of species”, k (constant), and “a fluctuating number of species”, i (a Poisson variate with the mean of μ); that is, j=k+i, where i, j and k are non-negative integers. The probability that j species occur in a quadrat is given by a Poisson-like distribution (extended Poisson), with two parameters k and μ. The mean species richness in the probability distribution is expressed by λ (=k+μ), and the variance is λ−k. The proposed model afforded a good fit for the observed frequency distribution of species richness per quadrat. If even one species is common among many quadrats, the mean number of species per quadrat is greater than the variance. The greater the number of common species among quadrats is, the larger is the value of k, and then the more pronounced is the difference between the mean and the variance (although the variance does not change). We fitted the model to 55 datasets collected by ourselves from grasslands in various locations (Tibet, Inner Mongolia, Slovakia, or Japan), with varying quadrat size (0.25, 0.0625, or 0.01m2), and under differing management status (various stocking densities).

Experimental Manipulation of Grassland Plant Diversity Induces Complex Shifts in Aboveground Arthropod Diversity.

Changes in producer diversity cause multiple changes in consumer communities through various mechanisms. However, past analyses investigating the relationship between plant diversity and arthropod consumers focused only on few aspects of arthropod diversity, e.g. species richness and abundance. Yet, shifts in understudied facets of arthropod diversity like relative abundances or species dominance may have strong effects on arthropod-mediated ecosystem functions. Here we analyze the relationship between plant species richness and arthropod diversity using four complementary diversity indices, namely: abundance, species richness, evenness (equitability of the abundance distribution) and dominance (relative abundance of the dominant species). Along an experimental gradient of plant species richness (1, 2, 4, 8, 16 and 60 plant species), we sampled herbivorous and carnivorous arthropods using pitfall traps and suction sampling during a whole vegetation period. We tested whether plant species richness affects consumer diversity directly (i), or indirectly through increased productivity (ii). Further, we tested the impact of plant community composition on arthropod diversity by testing for the effects of plant functional groups (iii). Abundance and species richness of both herbivores and carnivores increased with increasing plant species richness, but the underlying mechanisms differed between the two trophic groups. While higher species richness in herbivores was caused by an increase in resource diversity, carnivore richness was driven by plant productivity. Evenness of herbivore communities did not change along the gradient in plant species richness, whereas evenness of carnivores declined. The abundance of dominant herbivore species showed no response to changes in plant species richness, but the dominant carnivores were more abundant in species-rich plant communities. The functional composition of plant communities had small impacts on herbivore communities, whereas carnivore communities were affected by forbs of small stature, grasses and legumes. Contrasting patterns in the abundance of dominant species imply different levels of resource specialization for dominant herbivores (narrow food spectrum) and carnivores (broad food spectrum). That in turn could heavily affect ecosystem functions mediated by herbivorous and carnivorous arthropods, such as herbivory or biological pest control.

Plant functional diversity mediates the effects of vegetation and soil properties on community-level plant nitrogen use in the restoration of semiarid sandy grassland

Species-rich plant communities use nitrogen (N) more efficiently in grassland ecosystems; however, the role of plant functional diversity in affecting community level plant N-use has received little attention. We examined plant N content, stock and N-use efficiency at community-level along a restoration gradient of sandy grassland (mobile dune, semi-fixed dune, fixed dune and grassland) in Horqin Sand Land, northern China. We used the functional trait-based approach to examine how plant functional diversity, reflected by the most abundant species’ traits (community-weighted mean, CWM) and the dispersion of functional trait values (FDis), affected N-use efficiency in sandy grassland restoration. We further used the structure equation model (SEM) to evaluate the direct or indirect effects of plant species richness, biomass, functional diversity and soil properties on community-level plant N-use efficiency. We found that plant biomass and its N stock increased following sandy grassland restoration, and there were lower plant N content and higher N-use efficiency in semi-fixed dune, fixed dune and grassland as compared with mobile dune. N-use efficiency was positively associated with plant species richness, biomass, CWM plant height, CWM leaf C:N, FDis and soil gradient, but SEM results showed that species richness, CWM leaf C:N, plant biomass and FDis controlled by soil properties were the main factors exerting direct effects. CWM plant height also had a positive effect on N-use efficiency through its indirect effect on plant biomass. Soil gradient increased N-use efficiency through an indirect effect on vegetation rather than a direct effect. Final SEM models based on different plant functional diversity explained over 74% of variances in N-use efficiency. Effects of plant functional diversity on N-use efficiency supported both the mass ratio hypothesis and the complementarity hypothesis. Our results clearly highlight the important role of plant functional diversity in mediating the effects of vegetation and soil properties on community level plant N-use in sandy grassland ecosystems.

Social and environmental factors drive variation in plant and bird communities across urban greenspace in Sydney, Australia

We examined whether environmental or social factors alone, or a combination of social–ecological factors were more effective at explaining patterns in plant and bird assemblages across urban greenspaces. Thirty publicly accessible, passive recreation greenspaces provided by municipal councils (i.e. city parks) were surveyed in a highly urbanised city – Sydney, Australia. Plant communities were influenced most by topography and park management approach, and to a lesser extent by land-use history. Greenspaces with greater topographic variation and that were co-managed with local citizen groups hosted higher plant species richness and abundance. Bird species richness within greenspaces increased with increasing distance from the central business district and decreasing distance from freshwater. Bird abundance was best explained by a combination of social–ecological factors, with abundance increasing with increasing site (greenspace) age, increasing percent concrete groundcover of a site and increasing proximity to the central business district. We identified a group of ‘rare city parks’, dissimilar in ecological composition that hosted more complex and species rich plant communities compared to ‘common city parks’. We suggest this difference is likely because rare city parks received management and maintenance input from local citizen groups, whereas common city parks were managed and maintained exclusively by local councils. How different social factors, such as management approach and ongoing maintenance, are linked to the ecology of urban greenspaces are key areas for future investigation to help create sustainable urban landscapes that provide maximum benefits to urban residents.