Plant Diversity Research Articles

Modelling landscape-scale occurrences of common grassland species in a topographically complex mountainous environment

Mountainous regions typically harbour high plant diversity but are also characterised by low sampling intensity. Coarse-scale species distribution models can provide insights into the distribution of poorly sampled species, but the required bioclimatic data are often limited in these landscapes. In comparison, several environmental factors that vary over relatively fine scales in mountain environments (e.g. measures of topography) can be quantified from remotely-sensed data, and can potentially provide direct and indirect measures of biologically-relevant habitat characteristics in mountains. Therefore, in this study, we combine field-sampled floristic data with environmental predictors derived from remotely-sensed data, to model the ecological niches of 19 montane plant species in the Maloti-Drakensberg mountains, South Africa. The resulting models varied considerably in their performance, and species showed generally inconsistent responses to environmental predictors, with altitude and distance to watershed being most frequently included in models. These results highlight the species-specificity of the forb species’ environmental tolerances and requirements, suggesting that environmental change may result in re-shuffling of community composition, instead of intact communities shifting along gradients. Furthermore, while the relatively high importance of altitude (a proxy for temperature) and topographic wetness index (a proxy for soil moisture) suggest that the flora of this region will be sensitive to shifts in temperature and rainfall patterns, several non-climatic environmental variables were also influential. Our findings indicate that local response to climate change in mountains might be especially constrained by soil type and topographic variables, supporting the important influence of non-climatic factors in microclimatic refugia dynamics.

Ecosystem services in mountain pastures: A complex network of site conditions, climate and management

Mountain pastures offer a multitude of ecosystem services (ES) such as fodder for ruminants, habitat for pollinators, climate change mitigation, aesthetic landscape for recreation, and biodiversity conservation. We aimed at analysing to which extend these ES are influenced by small-scale gradients of climate, site conditions and management – and to disentangle relationships among ES and the factors influencing them. Therefore, we quantified ES on six mountain summer farms in two contrasting regions in Switzerland: the Northern Alpine Foothills (lower elevation, higher precipitation, calcareous bedrock) and the Eastern Central Alps (higher elevation, lower precipitation, silicious bedrock). We measured six ES indicators (forage quantity, forage quality, carbon storage, colour abundance, resources for pollinators, plant diversity) and related them to explanatory factors of climate (temperature and precipitation), site conditions (soil fertility, soil acidity, terrain slope) and management (local grazing intensity, remoteness) in 66 study plots, i.e., 11 per farm. A holistic picture of the complex relationships among these factors was drawn by various statistical approaches: allometric line fitting, variance partitioning, and structural equations modelling. We found a huge heterogeneity of ES indicators and explanatory factors on each farm: the variability within farms was even higher than between regions. Variance partitioning and structural equations modelling demonstrated strongest influence of climate and site conditions and revealed trade-offs among ES indicators: High forage quantity and quality were associated with low plant diversity and grassland aesthetics, whereas diversity, aesthetics and pollinator resources were positively correlated with each other. ES indicators were explained by a range of climatic and topographic factors: High precipitation reduced plant diversity, whereas temperature increased forage quantity and quality; slope reduced soil fertility, forage quantity, forage quality and carbon storage; soil fertility in turn increased forage quantity; the farther away a pasture was from the main farm building, the lower was the forage quantity and the higher the plant diversity. Although allometric relations among local grazing intensity and ES indicators were strong, the direct influence of the management factors measured on ES was surprisingly small: Cattle preferred areas of high forage quantity and quality, and carbon storage was higher in these areas. On the other hand, places less visited by cattle offered more pollinator resources, and showed higher aesthetics and plant diversity. Trade-offs among ES prevent the realisation of all ES at the same place, but heterogeneity of mountain pastures allows to realise a broad bundle of contrasting ES on each individual summer farm.

How did the diversity of woody plants in urban forests vary with the urban-rural gradient in Qingdao, China?

The distribution and diversity of woody vegetation are crucial for understanding the structure and ecology of urban forests. As urbanization accelerates, the construction and composition of urban forests vary significantly along the urban-rural gradient. Qingdao's urban forests offer an opportunity to test the relationship between the diversity of woody plants and the urban-rural gradient. We classified the urban-rural gradient using imperviousness and construction time, then investigated the diversity of woody plants in Qingdao's urban forests under different urban-rural gradients and tested the reasonableness of their allocation. Correlation analysis found that the diversity index of woody plants in urban forests was highly connected to the urban-rural gradient (by imperviousness: rMargalef Index = −0.589, rShannon-Wiener Index = -0.373, rPielouIndex = −0.170, rSimpson Index = 0.272/by construction time: rMargalef Index = −0.530, rShannon-Wiener Index = −0.360, rPielouIndex = −0.148, rSimpson Index = 0.272/0.174). With a decrease in urbanization density, the Margalef (H), Shannon-Wiener (H′), and Simpson (D) indices all decreased while the Pielou (E) index increased. The four diversity indices showed a substantial correlation with one another, but not with the Margalef and Pielou indices. The analysis utilizing the 10/20/30 rule of empirical demonstrates a clear irrationality in allocating shrub species in Qingdao's urban forests, and the distribution of tree species is reasonable. Based on the study results, strategies for optimizing and enhancing urban forests in Qingdao are proposed for different urban-rural gradients, respectively. This study can provide a scientific framework for urban biodiversity conservation and management in Qingdao and serve as a guide for urban forests and greening with comparable climates.

Varying patterns of taxonomic and functional plant composition and diversity across different types of urban and rural grasslands

AbstractSemi‐natural grasslands are found predominantly in agricultural landscapes; however, their counterparts are also found in cities, referred to as urban grasslands. We sampled the most extensive patches of urban grasslands in Wrocław (Poland, Europe) in urban parks and along a river valley. We compared urban grasslands to broadly defined rural grasslands in terms of compositional gradients and both taxonomic and functional diversity. We also tested for relationships between rare species and different facets of diversity. Urban grasslands corresponded to three rural grassland habitat types: mesic pastures, mesic meadows, and alluvial meadows. We conducted analogous analyses, including and excluding habitat‐level assignment, to determine if emerging patterns between rural and urban grasslands are habitat‐dependent. Rural pastures and their urban counterparts showed high taxonomic and functional similarity, implying that short‐ and frequent‐cutting, applied in cities, mimics grazing management on agricultural sites. Rural mesic hay grasslands and alluvial meadows showed high taxonomic and functional dissimilarities from their urban counterparts. We found that rare species contribute to taxonomic diversity while only affecting functional diversity in a few cases. Varying patterns of taxonomic and functional similarity were observed across different habitats. Comparisons of grasslands without regard for habitat types mask diverging patterns in taxonomic and functional diversity. Despite high environmental and management pressures in urban areas (higher nutrient levels and temperatures, decreased moisture, and intensified management and soil disturbances), we showed that urban grasslands hold a considerable portion of the plant diversity found in rural grasslands.

Diversity patterns of herbaceous community in environmental gradients of dehesa ecosystems

Dehesa is a unique ecosystem associated with high biodiversity, that integrates trees, livestock, and pasture, making agro-pastoral production compatible with sustainability. However, in the last few decades, a manifold of factors have caused a decline in tree vitality, density, and coverage, leading to long-term changes in species composition and ecosystem structure. This study aims to determine changes in the diversity of the herbaceous plant community in relation to environmental characteristics, the phytosanitary state of the holm oak (Quercus ilex L. subsp. ballota (Desf.) Samp.), and possible interactions with biotic agents, including Phytophthora cinnamomi. For this purpose, the floristic composition and alpha diversity of the understory were assessed in two dehesa stands in Southern Spain. Additionally, the spatial heterogeneity (beta diversity) patterns of herbaceous plants were evaluated in relation to a climatic gradient and subplot orientation at the regional, plot, tree, and subplot scales. Our findings show that microsite features and climate substantially impact the herbaceous plant community in dehesa stands. Annual precipitation is a crucial factor affecting the diversity and biomass of herbaceous plants on a broader, regional scale, consistent with its role as a limiting factor in the Mediterranean climate. However, site-level differences, such as soil clay content and plot slope angle, positively correlate with plant biodiversity, growth, and richness, varying with the Biodiversity Index considered. Moreover, microsites resulting from the combined effects of plot and tree are the main drivers of dissimilarities between samples, as expressed by beta diversity. Contrary to our initial hypothesis, our results reveal no significant association between tree health and herbaceous biodiversity decline.

Plant diversity enhances ecosystem multifunctionality via multitrophic diversity.

Ecosystem functioning depends on biodiversity at multiple trophic levels, yet relationships between multitrophic diversity and ecosystem multifunctionality have been poorly explored, with studies often focusing on individual trophic levels and functions and on specific ecosystem types. Here, we show that plant diversity can affect ecosystem functioning both directly and by affecting other trophic levels. Using data on 13 trophic groups and 13 ecosystem functions from two large biodiversity experiments-one representing temperate grasslands and the other subtropical forests-we found that plant diversity increases multifunctionality through elevated multitrophic diversity. Across both experiments, the association between multitrophic diversity and multifunctionality was stronger than the relationship between the diversity of individual trophic groups and multifunctionality. Our results also suggest that the role of multitrophic diversity is greater in forests than in grasslands. These findings imply that, to promote sustained ecosystem multifunctionality, conservation planning must consider the diversity of both plants and higher trophic levels.

Florabr: An R package to explore and spatialize species distribution using Flora e Funga do Brasil

AbstractPremiseThe Flora e Funga do Brasil project is the most comprehensive effort to reliably document Brazilian plant and fungal diversity. It involves the collaborative work of hundreds of taxonomists, integrating detailed and standardized morphological descriptions, nomenclatural status, and geographic distribution information of plants, algae, and fungi collected throughout Brazil. Despite the extensive information available, managing the information from the Flora e Funga do Brasil website poses certain challenges.Methods and Resultsflorabr is an R package developed to facilitate the exploration and geographical analysis of species information derived from the Flora e Funga do Brasil. Unique to florabr is its ability to interact with the latest, or any other version of the dataset, which undergoes weekly updates. I illustrate the practical application of florabr in common tasks in biogeography and conservation studies.Conclusionsflorabr is anticipated to be of significant interest to biogeographers, ecologists, curators of biological collections, and taxonomists actively contributing to the Flora e Funga do Brasil.

Out of and in East Asia: Phylogeny, biogeography and diversification of Thalictroideae (Ranunculaceae) in the Northern Hemisphere.

Understanding the biogeographical patterns and processes underlying the distribution of diversity within the Northern Hemisphere has fascinated botanists and biogeographers for over a century. However, as a well-known centre of species diversity in the Northern Hemisphere, whether East Asia acted as a source and/or a sink of plant diversity of the Northern Hemisphere remains unclear. Here, we used Thalictroideae, a subfamily widely distributed in the Northern Hemisphere with the majority of species in East Asia, to investigate the role of East Asia in shaping the biogeographical patterns of the Northern Hemisphere and to test whether East Asia acted as a museum or a cradle for herbaceous taxa. Based on six plastid and one nuclear DNA regions, we generated the most comprehensive phylogeny for Thalictroideae including 217 taxa (ca. 66% species) from all ten of the currently recognized genera. Within this phylogenetic framework, we then estimated divergence times, ancestral ranges, and diversification rates. The monophyletic Thalictroideae contains three major clades. All genera with more than one species are strongly supported as monophyletic except for Isopyrum, which is nested in Enemion. The most recent common ancestor of Thalictroideae occurred in East Asia in the late Eocene (ca. 36 Ma). From the Miocene onwards, at least 46 dispersal events were inferred to be responsible for the current distribution of this subfamily. East Asian Thalictroideae lineages experienced a rapid accumulation at ca. 10 Ma. The biogeographical patterns of Thalictroideae support the "out of and in East Asia" hypothesis, i.e., East Asia is both a source and a sink of biodiversity of the Northern Hemisphere. The global cooling after the middle Miocene Climatic Optimum, combined with the exposed land bridges due to sea-level decline, might have jointly caused the bidirectional plant exchanges between East Asia and other Northern Hemisphere regions. East Asia serves as evolutionary museums and cradles for the diversity of Thalictroideae and likely for other herbaceous lineages.

Vascular epiphytes of the South America Dry Diagonal: characterising their occurrence and richness in this neglected region

ABSTRACT The South America Dry Diagonal (SADD) is the most extensive and continuous portion of dry vegetation on the continent, characterised by lower rainfall and a marked dry season. Epiphytes are very poorly known and understudied in this area, even though they represent a high proportion of plant diversity in South America. Here, we compiled a dataset of epiphyte records from the SADD. The compiled epiphyte records date from 1859 to 2021, covering all four SADD domains, four countries, and 24 ecoregions. We utilised two databases for life form classification: Epilist and Brazil Flora Group. Our dataset contains 41,039 records distributed among 1119 epiphyte and hemiepiphyte species belonging to three main groups: angiosperms, ferns, and lycophytes. The SADD domains host a high number of unique species in each domain, with the Cerrado and Caatinga regions serving as primary hosts for the majority of species in the SADD dataset. Despite notable differences in species composition among domains, the least significant differences were observed between the Caatinga and Cerrado, as well as between the Chaco and the Pantanal. Orchidaceae, Bromeliaceae, and Polypodiaceae families exhibited the highest species diversity within the region. However, the species containing the highest number of specimens collected varied considerably among the domains. Herein, we also outlined some inconsistencies in the life-form classification across taxonomic bases, acknowledging the challenges of categorising epiphyte species while considering their intraspecific life-form variation.

Response of Herbaceous and Woody Plant Species in Southern Portugal to Cope Oak Decline Associated to Phytophthora cinnamomi

The decline of oak canopies in Iberian woodlands is strongly influenced by abiotic and biotic stress factors, such as the oomycete Phytophthora cinnamomi which has the capacity to infect a wide range of plant species. Understory plant diversity plays an important role in the epidemiology of P. cinnamomi in these ecosystems. This study aimed to identify a set of woody and herbaceous plants that can impact oak decline. Twenty-two herbaceous plant species from three families, and nineteen woody plants (trees and shrubs) from seven families were assessed for their response to infection by P. cinnamomi. Most of the herbaceous species did not show evident susceptibility, only a few exhibited significant biomass root reduction and just seven were identified as hosts. Yellow lupin was the only herbaceous species showing high susceptibility. Among the woody plant species, only two shrub and two tree species exhibited disease symptoms. The other ones, mostly hosts, ranged between low susceptible and tolerant. These results highlight the possibility that many of these species can maintain the pathogen active in the soil or even increase its population. In this context, the findings of this study can contribute to effective management strategies to mitigate Phytophthora infection in woodland soils.

Getting insights into chemical composition and antiherpetic capability of jujube (Ziziphus jujuba mill.) drupes

Food plant diversity in bioactive compounds makes them an exploitable resource in the search for effective natural products to prevent or treat viral infections. Therefore, in the framework aimed at studying the antiviral properties of extractive mixtures from fruits (and their waste) grown in the Campania Region (Italy), jujube drupes (Zizyphus jujuba Mill.) were our focus. The drupes were dissected into their peel, pulp and seed parts, each of which was extracted by ultrasound-assisted maceration and further fractionated, thus obtaining, beyond the sugar fraction, a polyphenolic fraction and a lipid fraction. UHPLC-HR MS/MS tools highlighted that the polyphenolic component of the seed was strongly dissimilar from that of the edible parts, being constituted by swertisin and its derivatives. Moreover, the peel mostly accounted for triglycosylated flavonols, whereas the pulp was rich in volatile aromatic glycosides. Among lipids, p-coumaroyl triterpenes mainly characterized the peel. All fractions were screened for their cytotoxicity, and non-toxic concentrations of each extract were tested against herpes simplex virus type 1 (HSV-1) by plaque assays. Molecular tests and Western blot analyses were also carried out. The jujube mixtures, in detail the peel and pulp polyphenolic fractions, and peel lipophilic fraction (the latter enriched mainly in ursane-type triterpenes), showed a marked inhibitory activity against HSV-1 acting in the early stages of viral infection and preventing attachment of the virus to the host cell. The acquired data suggest jujube active mixtures as promising candidates for the prevention and treatment of herpetic lesions.

Woody plants diversity and the associated provisioning ecosystem services across three contrasting forest management regimes in Southwest Ethiopia

Woody plants are a source of provisioning ecosystem services. Coffee management impacts forest composition, structure, and diversity. We studied the effect of coffee management intensification on woody plants and their associated provisioning ecosystem services under three contrasting forest management regimes in southwest Ethiopia. The study employed mixed approaches (vegetation assessment and ethnoecological study) to collect the data. Woody plants were collected from 189 plots and perceived local ecosystem services were identified by 136 individuals through an ethnoecological approach. The total number of woody plants recorded in the natural forest, coffee forest, and coffee agroforest was 971, 945, and 521 respectively. Species richness in natural forest, coffee forest, and coffee agroforest were 57, 54, and 53 respectively. The local people perceived 17 different provisioning ecosystem services collected from the three forest types. The result showed that there is a positive relationship between the diversity and use value of woody plants across the three forest management regimes. Coffee management intensification simplifies the stand structure, woody plant composition, and ecosystem services of the forest. Plant use value increases in coffee agroforests. Coffee agroforests can serve as repositories of diversity and ecosystem services in southwest Ethiopia.

Contrasting responses of plant, soil fungal and above‐ground arthropod communities to plant invasion across latitudes

Abstract The proliferation of alien species that can suppress resident species via biotic interactions represents a growing concern worldwide. Yet, how above‐ and below‐ground communities simultaneously respond to plant invasion, particularly across large spatial scales, remains poorly explored. We hypothesized plant invasion has a greater impact on recipient above‐ and below‐ground communities at lower than higher latitudes given that biotic interactions play a more significant role in shaping communities in more favourable, lower latitude environments. To test this hypothesis, we conducted a comprehensive field survey of 124 sites spanning a 1700‐km latitudinal gradient in China, to explore the effects of invasion of Alternanthera philoxeroides, a globally widespread invasive plant, on plant, soil fungal and above‐ground arthropod communities. Invasion of A. philoxeroides had divergent effects on beta diversity (i.e. variation in taxa composition among sites) of plants, above‐ground arthropods and soil saprotrophic fungi, with negative, neutral and positive responses, respectively. Notably, the compositional dissimilarity of plant and arthropod communities between adjacent invaded and non‐invaded sites remained constant across latitudes. In contrast, the compositional dissimilarity of the entire and pathogenic fungal communities between adjacent invaded and non‐invaded sites increased with latitude. This resulted in a decreasing difference in invasion effects on the composition of plant and fungal communities with increasing latitude. Synthesis. Our study provides novel insights into the complexities of invasion effects by revealing contrasting responses of above‐ and below‐ground communities to plant invasion across latitudes. The contrasting responses could weaken or reshape above‐ and below‐ground interactions, and, in turn, affect future species invasions and the functioning of terrestrial ecosystems.

How do species richness and colour diversity of plants affect public perception, preference and sense of restoration in urban green spaces?

Urban development has led to an overlap between natural and artificial environments, affecting individuals’ experiences with nature. To create high-quality urban natural environments, it is crucial to understand the residents’ perceptions, preferences and psychophysical health benefits concerning biodiversity. This study, employing various experimental designs, investigated the perceptions, preferences and restorative experiences of 695 participants concerning different levels of plant species richness and colour diversity in four typical urban green space types (lawn, forest, square and streetscape). The following discoveries were made: (i) The colour diversity carried by vegetation in lawns was an important basis for the public to identify plant diversity. Lawns with high richness achieved by different grass species (that have green colour) were not preferred by the public, and increased colour diversity that can be achieved by adding flowering plants (forbs) was preferred by people more than a single green lawn. The species richness of forests was positively correlated with public perception, preference and perceived restoration, with single green forests being preferred by the public. Additionally, people preferred vegetated environments over unvegetated squares or streetscapes. (ii) Participants’ perceptions, preferences and perceived restoration were positively correlated. Their preference for and perceived restoration from plant diversity depended more on their perception of it than on the actual species richness. (iii) Participants’ gender, expertise, physical condition, ecological knowledge, childhood living environment, frequency of use and accessibility of green spaces, natural orientation (connectedness), gardening, sense of security and well-being all influenced their perceptions, preferences and perceived restoration from plant diversity to varying extents. Significant distinctions were found between different forms of experimental design. Combining between-subject and within-subject designs could both control individual errors to some extent and avoid long-term effects on the participants compared to using either design alone. These findings provide a theoretical basis and practical approach for future biodiversity-oriented urban green space planning and management to better maximise the ecological and social service benefits of urban green spaces.

Mixed reproduction modes explain a high genetic diversity in the invasive plant *Ludwigia grandiflora* subsp. *hexapetala* in western Europe

Mixed reproduction modes explain a high genetic diversity in the invasive plant *Ludwigia grandiflora* subsp. *hexapetala* in western Europe

Regulation of photosynthetic carbon fate by plant diversity and nutrients in abandoned farmland on the Loess Plateau

Understanding the distribution and transfer of photosynthetic carbon (PC) in ecosystems is important to determine the fate of soil carbon (C). However, the allocation on plants of newly fixed PC during secondary succession is unknown. Using in-situ 13CO2 pulse labeling we report characteristics of PC turnover and driving factors that drive it in plants and soils at different successional stages on the Loess Plateau, China. Within 30 d of labeling, 13C abundance significantly decreased in plant leaves and stems, and significantly increased in roots, especially on farmland abandoned for 30a (from 114.67 mg·m−2 to 225.08 mg·m−2). The abundance of 13C in soils significantly increases over time, with 13C abundances in bulk soil 8a after abandonment being 8.17 % higher than those after 30a and 9.34 % after 15a. The contribution of newly fixed PC to soil organic carbon (SOC) was also significantly higher in soil 8a after abandonment than after 15a and 30a. Plant diversity and nutrients are the main factors to drive PC fixation and transfer. Because farmland abandoned for 8a has low plant diversity, high species evenness, and high plant nutrient contents, its plant-soil system fixes more PC. Plant diversity is a key predictor of PC fixation, and plant nutrients have an important influence on the transfer of PC. These results provide improve our understanding of vegetation restoration and terrestrial carbon sequestration in abandoned farmlands.

Plateau zokor disturbance enhances soil bacterial diversity and reduces network complexity

Rodent disturbances are considered as the key factors that affect grassland ecological restoration worldwide. Although the impact of rodent disturbances on plant diversity and ecosystem functions has been extensively studied, our understanding of how such activities shape soil bacterial community networks and their functional roles remains limited. In this study, we employed 16S rRNA sequencing to investigate soil bacterial communities between undisturbed alpine meadow and zokor mounds at different successional stages. Additionally, we analyzed the co-occurrence networks and potential functions within the alpine meadow ecosystem. The results revealed that (1) the disturbance by plateau zokors altered the soil bacterial community structure, increased bacterial diversity and reduced network complexity. Also, there were synergistic interactions among key species in the soil bacterial co-occurrence network; (2) soil organic carbon (SOC) and total nitrogen (TN) were identified as the key environmental variables that shape soil bacterial communities; (3) functional predictions based on FAPROTAX indicated that the disturbance by plateau zokors significantly affected the functional groups involved in carbon (C) and nitrogen (N) cycling. Overall, these findings significantly enhance our understanding of how small mammal activities influence the soil nutrient cycling and bacterial community in the Qinghai-Tibet Plateau (QTP) alpine meadow.

The impact of Nassella trichotoma (Nees) Hack. ex Arechav. on plant diversity, richness and soil properties in South Africa

Nassella trichotoma (Poaceae) is a highly invasive South American grass that is invading montane grasslands in the Eastern and Western Cape provinces of South Africa. Although N. trichotoma has been recognised as a major problem in these mountains for decades, the primary concern has been on impacts on rangeland productivity and management, while the impacts of invasions on plant biodiversity have not been considered. To understand the impact of N. trichotoma on local plant biodiversity, 81 pairs of plots (total of 162 plots) were laid out in the Sneeuberg and Eastern Cape Drakensberg mountains, Eastern Cape, in March 2020 and March 2021. At each site plots were located in grassland invaded by N. trichotoma and in nearby uninvaded grassland (control). A total of 20 N. trichotoma patches were sampled with two to four plot pairs per site. All vascular plant species were recorded in all plots, the cover abundance of each species per plot was visually estimated, and the topsoil was sampled and analysed for differences in nutrient and physical factors between invaded and uninvaded plots. Plant species diversity was 24 % higher in uninvaded areas, and the native grasses Pentameris airoides (Χ2 = 4.93, d.f. = 1, p < 0.01), Tenaxia disticha (Χ2 = 5.51, d.f. = 1, p < 0.01), and Themeda triandra (Χ2 = 9.28, d.f. = 1, p < 0.001) were significantly less abundant in invaded plots. Uninvaded areas had greater native species diversity (65 species) and fewer alien species (3) than invaded areas (47 and 9 respectively). Of the 18 soil variables measured, the following were significantly higher in invaded areas than uninvaded areas: boron (23 %), calcium (18 %), phosphorous (58 %), silt (10 %), total cations (12 %), and zinc (68 %). This suggest that N. trichotoma alters soil nutrients. The results indicate that N. trichotoma is a powerful driver of native biodiversity erosion in these montane grasslands and should be a cause for major concern by landowners and government.

Plant phylogenetic diversity along the urban–rural gradient and its association with urbanization degree in Shanghai, China

ContextThe spatial distribution of plant diversity in urban areas is fundamental to understanding the relationship between urbanization and biodiversity. Previous research has primarily focused on taxonomic levels to assess species richness. In contrast, investigations into the spatial patterns of phylogenetic diversity in urban plants remain limited.ObjectivesThis study aims to investigate the spatial patterns of plant phylogenetic diversity along an urban–rural gradient and quantify how phylogenetic diversity and the degree of urbanization are related.MethodsA survey of vascular plants was conducted at 134 randomly selected sample plots along four urban–rural transects in Shanghai, China. Three phylogenetic diversity metrics were calculated: Faith’s phylogenetic diversity (PD), net relatedness index (NRI), and net nearest taxon index (NTI), along with the urbanization degree index (UDI). Regression analysis was employed to quantify the spatial patterns of plant phylogenetic diversity across different taxa along the urban–rural gradients and their relationships with UDI.ResultsThe study observed seven distinct patterns of plant phylogenetic diversity along the urban–rural gradients in different taxa, which support the previous hypotheses that biological distribution patterns at the species level also hold true at the phylogenetic level. Faith’s phylogenetic diversity (PD) showed a linear increase with increasing UDI for total, woody, perennial, and cultivated plant assemblages. The UDI explained 3–36% of the variation in PD for these taxa. In contrast, PD for annual and spontaneous plants exhibited a linear decrease with increasing UDI, which explained 25% and 3% variation in PD for annual and spontaneous plants, respectively. The net relatedness index (NRI) for woody, perennial, and cultivated plants, as well as the net nearest taxon index (NTI) for perennial and cultivated plants, linearly increases with UDI, whereas the NRI for total, annual, and spontaneous plants, as well as NTI for total, woody, annual, and spontaneous plants linearly decrease with UDI. However, some of these trends were only marginally significant.ConclusionsThe spatial patterns of plant phylogenetic diversity varied along the urban-to-rural gradients, indicating that urban environmental filtering has an impact on plant phylogenetic diversity. Urbanization increased the phylogenetic richness of different plant taxa in Shanghai but resulted in more clustering and relatedness of species within plant assemblages. Phylogenetic richness exhibited a linear increase with UDI, while the phylogenetic divergence decreased with UDI. The UDI is a useful predictor for examining variations in plant phylogeny due to urbanization. Our findings provide insights into how urbanization impacts plant phylogenetic diversity, helping urban plant diversity conservation.

Integrated vegetation management within electrical transmission landscapes promotes floral resource and flower-visiting insect diversity.

Electrical transmission rights-of-way are ubiquitous and critical infrastructure across the landscape. Active vegetation management of these rights-of-way, a necessity to deliver electricity more safely, maintains these landscape features as stages of early successional habitat, a rarity in many regions, making these areas viable movement corridors for many taxa. The goals of this study were to (i) evaluate the effects of different electrical transmission landscape management practices on flowering plant and flower-visiting insect diversity parameters and (ii) generate conservation management inferences for these landscapes. In this study we tested the impact of three vegetation management levels across 18 electrical transmission sites. We evaluated the effects of treatment on bloom abundance and species richness as well as flower-visiting insect abundance and family richness. We identified 76541 flowers/inflorescences across 456 transects, including 188 species in 56 plant families. Additionally, we obtained data on 11361 flower-visitoring insects representing 33 families from 2376 pan trap sets. High vegetation management favored the reduction of coarse woody debris in the sites and harbored the highest level of abundance and richness of both floral resources and flower-visiting insects. We discuss that we can align social and ecological values of rights-of-way, ensuring their sustainability by applying regular and targeted integrated vegetation management. Thus, we can use rights-of-way landscapes not only as an effective management strategy for the delivery of essential human services, but also to provide conservation benefits for wild pollinators.