Herbaceous Growth Form Research Articles

Different sets of traits determine transition of alien species along the invasion continuum

Invasive alien species are currently considered as one of the dominant drivers of global environmental change. Till now, the majority of studies have focused on single or a few traits of alien species that facilitate their invasion. Also inclusion of all the traits which determine the transition of aliens along the different stages of invasion continuum (casual, naturalised and invasive) has remained largely overlooked. In this study, we collected a comprehensive trait dataset on 144 alien plant species of Kashmir Himalaya – a global biodiversity hotspot region. To test which traits of alien species, individually or in combination along with anthropogenic factors, determine their transition along the invasion continuum, we employed chi-square tests, boosted regression trees and phylogenetic methods. We found the perennial life span, longer residence time, greater number of introduced regions, and better seed dispersal mechanism were critical in determining the transition from casual to naturalised. The herbaceous growth form, therophyte Raunkiaer life-form, annual life span, achene fruit, longer residence time and broader introduced range were the species' traits determining transition from naturalised to invasive. Aliens introduced as ornamentals have more propensity to become naturalised; whereas aliens introduced unintentionally show overrepresentation at the invasive stage. Phylogeny alone showed mixed results indicating both clustering and dispersion; however, in combination with other traits, it plays a significant role in determining the stage of invasion. Overall, our study disentangles the individual and interactive roles of multiple traits that determine the transition of alien species' along the invasion continuum. Further, we foresee the potential applicability of our findings in designing robust invasion risk analysis protocols and stage-specific invasion management strategies in this Himalayan region, with learnings for elsewhere in the world.

Floristic composition, life history traits and phytogeographic distribution of forest vegetation in the Western Himalaya

IntroductionScientific documentation of the qualitative forest vegetation parameters of a biogeographical area provides baseline information to guide conservation strategies and design policies for biodiversity management regulations.MethodsWe present one of the most comprehensive qualitative vegetation analyses to evaluate the entire structure and function of an ecosystem in the remote northern part of the Kashmir Himalaya, India. Several multivariate ecological community analyses were conducted after determining the presence of plant species in the various habitats using a random sampling technique.ResultsIn total, 155 plant species belonging to 120 genera and 49 families occurred in the area. Asteraceae was the largest family (12% of plant species) followed by Rosaceae (11%). The patterns of species distribution across families were uneven, with 50% of the species belonging to only 7 families, and 23 families being monotypic. In terms of functional groups, the herbaceous growth form dominated. Therophytes were the dominant life form, indicating that the vegetation was disturbed. According to the phytogeographical research, 65% of the species documented in the study area were native, 15% were invasive, 14% naturalized, and 5% being casual. The majority (30%) of exotic species were reported along roadsides. Of all the species found, 39% grew in their natural habitats, such as forests, and 11% were scattered along roadsides. Plant species were grouped in five different clusters based on their floristic similarity. According to the estimated diversity indices, natural forest has the greatest values for Shannon’s and Simpson’s index. We found that the study area serves as the natural habitat for several significant, endangered medicinal plants, including Arnebia benthamii, Bergenia ciliata, Delphinium roylei, Gentiana kurroo, Phytolacca acinosa, Saussurea costus, and Trillium govanianum. Therefore, we recommend that human intervention in natural regeneration efforts be prioritized in these habitats to increase the population of these species.ConclusionExamining species features from the perspective of functional groups contributes to our understanding of the ecological aspects of the flora. It may also be useful in developing management plans to ensure long-term management of forest landscapes in this remote Himalayan region.

Solutions to fire and shade: resprouting, growing tall and the origin of Eurasian temperate broadleaved forest.

Tree species of Eurasian broadleaved forest possess two divergent trait syndromes with contrasting patterns of resource allocation adapted to different selection environments: short-stature basal resprouters that divert resources to a bud bank adapted to frequent and severe disturbances such as fire and herbivory, and tall trees that delay reproduction by investing in rapid height growth to escape shading. Drawing on theory developed in savanna ecosystems, we propose a conceptual framework showing that the possession of contrasting trait syndromes is essential for the persistence of broadleaved trees in an open ecosystem that burns. Consistent with this hypothesis, trees of modern Eurasian broadleaved forest bear a suite of traits that are adaptive to surface and crown-fire regimes. We contend that limited opportunities in grassland restricts recruitment to disturbance-free refugia, and en masse establishment creates a wooded environment where shade limits the growth of light-demanding savanna plants. Rapid height growth, which involves investment in structural support and the switch from a multi-stemmed to a monopodial growth form, is adaptive in this shaded environment. Although clustering reduces surface fuel loads, these establishment nuclei are vulnerable to high-intensity crown fires. The lethal effects of canopy fire are avoided by seasonal leaf shedding, and aerial resprouting enhances rapid post-fire recovery of photosynthetic capacity. While these woody formations satisfy the structural definition of forest, their constituents are clearly derived from savanna. Contrasting trait syndromes thus represent the shift from consumer to resource regulation in savanna ecosystems. Consistent with global trends, the diversification of most contemporary broadleaved taxa coincided with the spread of grasslands, a surge in fire activity and a decline in wooded ecosystems in the late Miocene-Pliocene. Recognition that Eurasian broadleaved forest has savanna origins and persists as an alternative state with adjacent grassy ecosystems has far-reaching management implications in accordance with functional rather than structural criteria. Shade is a severe constraint to the regeneration and growth of both woody and herbaceous growth forms in consumer-regulated ecosystems. However, these ecosystems are highly resilient to disturbance, an essential process that maintains diversity especially among the species-rich herbaceous component that is vulnerable to shading when consumer behaviour is altered.

Soil seed bank distribution and restoration potential in the vegetation of Buska Mountain range, Hamar district, southwestern Ethiopia

The seed banks are vital components for the reestablishment of degraded lands since they are used to predict the future coverage of vegetation and allow for the implementation of appropriate conservation measures in a particular area. The study was conducted in the Buska Mountains of the Hamar area in south-western Ethiopia and determined the composition, density and vertical distribution of soil seed banks under various land-use systems and soil layers. A total of 96 soil samples were involved in the study; four land-use types (grassland, forest, scrub and bare ground). Three distinct soil layers from each plot (0–3 cm, 3–6 cm, 6–9 cm depths) were sampled. Jaccard's Similarity Coefficient was applied to evaluate the correspondence between different land-use types and soil layers. One-way ANOVA was used to compute species density and composition respectively within land-use systems along with the seed bank and above ground vegetation. Fifty six (56) species within 27 plant families and 50 genera were recorded. Twenty percent of the species was contributed by Asteraceae followed by Poaceae (16%). Herbaceous growth forms were the most dominant in the area, contributing about 78.6%. The total seedling density in the study plots was 8171 seedlings/m2. Jaccard's Similarity Coefficient is relatively higher (0.52) between grassland and scrub, while the forest and bare land had the least amount of similarity (0.22). There was seen a higher similarity of species between the first and second soil layers and a decreasing density with soil depth. A substantial difference between the aboveground species and seed bank was recorded in the area. The lower resemblance between the standing vegetation and the seed bank infers a lower overall restoration potential and suggests other alternative regeneration mechanisms such as seedling plantation of priority indigenous plant species and avoiding anthropogenic disturbances.

Diversity, distribution and drivers of alien flora in the Indian Himalayan region

The Himalaya – a global biodiversity hotspot – harbors diverse flora and fauna, but increasingly beset with multiple threats, including biological invasion by alien species. Here, we aimed to investigate the diversity, distribution, and drivers of alien flora in the Indian Himalayan Region (IHR), a region spread across 12 states/union territories in India. We developed a comprehensive checklist on alien flora of IHR based on review of 141 studies published during the years 1934 to 2022, and further disentangled the key environmental (average annual rainfall, total area, protected area, forest area, total plant richness) and socioeconomic (total population, traffic length) drivers that better explain regional alien and naturalized plant richness. We recorded 771 alien plant species, including 375 cultivated and 396 naturalized species. We found that the species native to Southern America and those with perennial life span and herbaceous growth form were most represented in the IHR. Similarly, the annual herbs native to Southern America had a higher probability to become naturalized in the IHR. Based on the species composition of the total alien and naturalized flora distributed across different parts of the IHR, we found evidence of distance decay of floristic similarity. The total alien plant richness was best explained by the average annual rainfall, while the naturalized plant richness was best predicted by total traffic length. Our results identify the key environmental (i.e., average annual rainfall) and socioeconomic (i.e., total traffic length) drivers that determine the diversity and distribution patterns of alien and naturalized plants in the IHR. Our findings have practical applications in developing a scientifically-informed management and policy framework to mitigate the impacts of plant invasions and to predict the potential future plant invaders in the Himalaya. Overall, the checklist of alien flora of the IHR represents a step forward in filling the knowledge gaps on biological invasions from the Himalaya – a globally data-deficient region. • Diversity, distribution and drivers of alien flora in Indian Himalayan Region studied. • The alien flora comprise of 771 species, including 375 cultivated and 396 naturalized. • Annual herbs from Southern America showed higher naturalization probability. • Total alien plant richness was best explained by the average annual rainfall. • Naturalized plant richness was best predicted by total traffic length.

Ethnogynaecological Knowledge of Traditional Medicinal Plants Used by the Indigenous Communities of North Waziristan, Pakistan.

Background Since the beginning of civilization, medicinal plants have been used in human healthcare systems. Studies have been conducted worldwide to evaluate their efficacy, and some of the results have triggered the development of plant-based medications. Rural women in Pakistan frequently experience gynaecological disorders due to malnutrition and heavy physical work during pregnancy. Due to the low economic status, the remoteness of the area, and the lack of modern health services, herbal therapy for gynaecological disorders is common among the indigenous tribes of the study area. Methods Field surveys were carried out from April 2018 to October 2020 to collect data regarding medicinal plants used for different gynaecological disorders. A semistructured questionnaire was used to collect ethnogynaecological data. Results In total, 67 medicinal plant species belonging to 38 families are being used to treat 26 different gynaecological problems. The herbaceous growth form and the Lamiaceae family were recorded with the maximum number of plant species (42 species and 7 species, respectively). Leaves are the most highly utilized plant part, with 16 species. In the case preparation method, decoction was the dominant method (25 species, 36.76%). The informants reported the maximum number of species for the treatment of irregular menstrual flow as 11 species (15.28%). The highest relative frequency of citation (RFC) value was obtained for Acacia modesta (0.37), and the use value (UV) for Tecomella undulata (0.85). The highest informants' consensus factor (ICF) value (1.0) was obtained for emmenagogue and tonic each after delivery. The highest consensus index (CI%) value was calculated for Acacia modesta (36.92%). The Lamiaceae had the highest family importance value (FIV) (98.46%). Conclusion This is the first ever quantitative study focusing mainly on ethnogynaecological study conducted in the tribal areas of North Waziristan which highlights the importance of traditional herbal remedies for their basic medical requirements. The results of this study would serve as a baseline for advanced phytochemical and pharmacological screening, as well as conservationists for further studies.

The ecological drivers of growth form evolution in flowering plants

Abstract In flowering plants (angiosperms), the herbaceous habit has evolved repeatedly from the ancestral woody state and herbs evolved repeatedly back to woody plants. Yet, how common these transitions were and which ecological conditions promote the herbaceous habit is poorly known. Several hypotheses exist, postulating an advantage of the herbaceous growth form to better cope with frost, drought, fire and shade and in allowing a fast life strategy, but their evaluation has been hitherto limited and support equivocal. We aim to evaluate these hypotheses by testing the difference between woody plants and herbs for a set of variables related to these hypotheses. We compiled and integrated data for up to 21,581 species representing 359 families from public databases. We estimated the minimum number of evolutionary transitions between both growth forms. We assembled data on frost, drought, fire and shade tolerances, clonality and specific leaf area and we tested individual hypotheses by comparing herbaceous and woody angiosperm growth forms globally and within selected biomes and clades using phylogenetic comparative analyses. We found 1656 evolutionary transitions from woody towards herbaceous growth form and 2111 transitions in the opposite direction. In agreement with our expectations, herbs were more tolerant to frost and shade than woody plants and had higher specific leaf area. However, the growth forms did not differ in their fire tolerance and clonality. Furthermore, contrary to our expectation, woody plants were more drought tolerant than herbs. The majority of the differences were robust to the choice of biome or clade. Synthesis. Both herbaceous and woody habits evolved many times making the evolution of growth forms a well‐replicated event and suggesting that conditions favourable for either of the growth forms emerge often and plants respond to them. Apart from standard explanation by low temperatures, the success of herbs was likely enabled also by biotic interactions—by their fast life strategy, which is beneficial in seasonal and early successional habitats, and by their ability to tolerate shade.

Introduction history mediates naturalization and invasiveness of cultivated plants

AbstractAimSpecies characteristics and cultivation are both associated with alien plant naturalization and invasiveness. Particular species characteristics are favoured for cultivation, obscuring the relationship between traits and naturalization success. We sought to better understand the drivers of naturalization and invasiveness by analysing relationships with species characteristics and cultivation and by disentangling the direct effects of characteristics from the indirect effects mediated by cultivation.LocationGreat Britain.Time periodc. 1000–present.Major taxa studiedSeed plants.MethodsWe used a comprehensive dataset of 17,396 alien plant taxa introduced to Great Britain before 1850, a country with one of the most well‐documented histories of plant introductions. We integrated this with cultivation data from historical and modern records from botanic gardens and commercial nurseries and with trait data. Accounting for time since introduction, we quantified the influences of cultivation and species characteristics on present‐day naturalization and invasiveness in Great Britain.ResultsLarger native range size, earlier flowering, long‐lived herbaceous growth form, and outdoor cultivated habitat were all associated with naturalization. However, these relationships between characteristics and naturalization largely reflected cultivation patterns. The indirect, mediating influence of cultivation on naturalization varied among species characteristics, and was relatively strong for growth form and weak for native range size. Cultivation variables, particularly availability in present‐day nurseries, best explained invasiveness, while species characteristics had weaker associations.Main conclusionsHuman influence on species introduction and cultivation is associated with increased probability of naturalization and invasiveness, and it has measurable indirect effects by biasing the distribution of species characteristics in the pool of introduced species. Accounting for human cultivation preferences is necessary to make ecological interpretations of the effects of species characteristics on invasion.

Plant Species Classification and Diversity of the Understory Vegetation in Oak Forests of Swat, Pakistan

The forest ecosystem has understory vegetation that plays a vital role in sustaining diversity, providing nutrients, and forming a useful association for developing a balanced ecosystem. The current study provides detailed insights into the plant biodiversity and species classification of the understory vegetation of Swat, Pakistan. The floral diversity of the area was comprised of 58 plant species belonging to 32 families. The physiognomy of the studied area was dominated by herbaceous growth form with 47 species. The dominant life-form class was hemicryptophytes with 19 species (33%), followed by nanophanerophytes with 15 species (26%) and therophytes with 13 species (22%). Of the 58 species, 43 plant species were associated with group III clustered by applying Ward’s agglomerative clustering that indicated wide sociability of the species in the studied oak-dominated forests. Group III had higher species richness (10.3), α-diversity (2.74) and β-diversity (9.85), and Margalef index values (3.95). While the group I had maximum Pielous and Simpson index values of 0.97 and 7.13, respectively. Redundancy analysis revealed that seven variables (i.e., latitude, elevation, clay, wilting point, bulk density, saturation, and electric conductivity) were significantly influential concerning the understory vegetation of oak-dominated forests. The understory vegetation of these forests plays an important role in the forest ecosystem of the region. The present study reveals floral divergence and physiognomic scenario of the unexplored study area, which could be an important reference for future ethnobotanical, phytosociological, and conservational endeavors. Moreover, this information is important to the success of efforts intended to prevent the loss of species diversity in these forests by destroying their natural habitats.

Evolution of herbs: key to the conundrum might be tolerance not avoidance

Abstract Aims Woody plants represent the ancestral growth form in angiosperms with herbs evolving repeatedly from them. While there are a number of hypotheses about drivers of the evolution of the herbaceous habit, the ability to avoid frost damage in winter by discarding their aboveground biomass has often been invoked as the main force in their evolution. We propose instead that any unpredictable disturbance might have been much more important than the seasonal frost, as herbs easily survive repeated disturbance. Methods We tested this hypothesis by comparing herbs and woody plants in their ability to deal with three types of simulated disturbances, more predictable winter freezing, less predictable spring freezing and herbivory. Comparison was made in an experimental common garden setup with 20 species differing in woodiness. We evaluated the effects of these disturbances on mortality and regrowth of plants. Important Findings Herbs did not have an advantage over woody plants in survival when exposed to winter freezing. In less predictable conditions of spring freezing herbs survived the treatment better than woody plants and this advantage was even larger in case of the simulated herbivory treatment. The advantage of herbs over woody plants in less predictable conditions suggests that herbaceous growth form might be an adaptation to unpredictable disturbance, which herbs are able to tolerate thanks to their ability to survive loss of aboveground biomass. Consequently, factors such as mammal herbivory or fire might have been the most likely factors in the transition from woody species to herbs.

Observations on the floristic, life-form, leaf-size spectra and habitat diversity of vegetation in the Bhimber hills of Kashmir Himalayas

Vegetation analysis provides the prerequisites to understand the overall community structure and function of any ecosystem and is a fundamental requirement for the precise evaluation of biodiversity. Although many studies have assessed floristic attributes of specific areas, there are still unexplored regions, as is the case of the mountain region in the Kashmir Himalayas. Current research highlighted the recent findings of the scientific characterization of floristic and ecological aspects on the forest flora found in the Bhimber hills, Pakistan. Floristically, a total of 93 species belonging to 80 genera in 41 families were recorded. The species distribution patterns across the families were disproportionate with half of the species contributed by 8 families and 25 families were monotypic. Based on the floristic analysis, Asteraceae was the largest family with 12% of species followed by Poaceae with (11%) species. PAST software, a multivariate ecological community analysis was used to classify the species similarities and differences among the different habitat types. According to the habitat wise distribution, 21% of species were growing in the natural forest habitat, while 15% of species were dispersed in highly distributed habitats along roadsides and 8% on pedestrians. In terms of functional diversity, the herbaceous growth form was dominant (58%). The biological spectrum revealed therophytes as the dominant life form as it indicates the disturbed habitat vegetation. The phytogeographical analysis revealed that the maximum (69%) species were native, while the minimum (31%) species were exotic. Thus, the study of these functional and habitat diversity patterns can significantly improve our understanding of the ecological aspects of the flora in the geographical location. This information may additionally be useful in devising management plans to ensure sustainable utilization and better management of forest landscapes in this Himalayan region.

Floristic diversity and correlates of naturalization of alien flora in urban green spaces of Srinagar city

The sustainable management of green spaces in cities is crucial in achieving the challenging goal of urban sustainability. The common practice of cultivation of alien plants in urban green spaces is often associated with risk of naturalisation (i.e. escape into wild), which can have sometime adverse impacts on biodiversity and ecosystem services. To mitigate these risks, understanding patterns and processes of naturalisation of alien flora in urban green spaces becomes crucial. Here we report the floristic diversity of alien flora and correlates of its naturalisation in the green spaces of Srinagar city – one of the largest urban centres in the Himalaya. We documented 342 plant species belonging to 66 families from the green spaces of Srinagar, predominantly represented by 245 alien species (72%). Among the alien species pool, 133 species (54%) are exclusively under cultivation (non-escapes) and 112 species (46%) grow in the wild (cultivation escapes and accidentally introduced species); and of the latter, 51 were naturalised, 39 casual and 22 invasive. The cultivated alien species escaped into the wild belong to 27 families, and most prominently to the Asteraceae. Habitat-wise, plant dumping sites in the green spaces constituted the most dominant habitat of cultivation escapes. A significant relationship was revealed between the proportion of aliens under cultivation and species traits such as growth form, life span and residence time; and plant species with herbaceous growth form, annual life span and relatively longer residence time showed higher proportion of naturalisation. We found a significant correlation between abundance of the cultivation escapes and residence time (r = 0.507). The present study has generated policy-relevant data on urban green spaces of Srinagar, which can support policy regulations to steer the sustainable development of this rapidly urbanising Himalayan city.

Growth plasticity in response to shading as a potential key to the evolution of angiosperm herbs

In angiosperms, herbs evolved from ancestral woody growth form. A number of hypotheses on what was the driver of their evolution have been proposed, but none of them has received clear support so far. We are putting forward a new hypothesis that an important advantage of the herbaceous growth form lies in its greater capacity for plastic response to neighbour shading. Since most herbs form aboveground structures only for 1 year, they can respond to light heterogeneity more plastically than woody plants with long-living structures which need to pursue long-term goals such as stability and upward growth. To test the hypothesis, we carried out an experiment comparing plastic response to directional green shading of 21 species of young herbaceous and woody plants. We measured change of their tilt and length and compared it between herbs and woody plants using phylogenetic techniques. Both herbs and woody plants in our experiment responded to directed green shading by growing away from the shading plastic film. Overall response of herbs was, in agreement with the hypothesis, slightly stronger than response of woody plants, although there was high interspecific variation. The data indicate that herbs indeed have greater plasticity of stem growth in response to neighbour shading than woody plants, although the overall difference is not very strong. This capacity for plastic response might have played a role as one of the drivers of the evolution of the herbaceous growth form.

The effects of evolutionary and environmental variance on estimates of phylogenetic diversity in temperate forest plots

AbstractAimsPhylogenetic diversity metrics can discern the relative contributions of ecological and evolutionary processes associated with the assembly of plant communities. However, the magnitude of the potential variation associated with phylogenetic methodologies, and its effect on estimates of phylogenetic diversity, remains poorly understood. Here, we assess how sources of variation associated with estimates of phylogenetic diversity can potentially affect our understanding of plant community structure for a series of temperate forest plots in China.MethodsIn total, 20 forest plots, comprising of 274 woody species and 581 herbaceous species, were surveyed and sampled along an elevational gradient of 2800 m on Taibai Mountain, China. We used multi-model inference to search for the most parsimonious relationship between estimates of phylogenetic diversity and each of four predictors (i.e. type of phylogenetic reconstruction method, phylogenetic diversity metric, woody or herbaceous growth form and elevation), and their pairwise interactions.Important FindingsThere was no significant difference in patterns of phylogenetic diversity when using synthesis-based vs. molecular-based phylogenetic methods. Results showed that elevation, the type of phylogenetic diversity metric, growth form and their interactions, accounted for >44% of the variance in our estimates of phylogenetic diversity. In general, phylogenetic diversity decreased with increasing elevation; however, the trend was weaker for herbaceous plants than for woody plants. Moreover, the three phylogenetic diversity metrics showed consistent patterns (i.e. clustered) across the elevational gradient for woody plants. For herbaceous plants, the mean pairwise distance showed a random distribution over the gradient. These results suggest that a better understanding of temperate forest community structure can be obtained when estimates of phylogenetic diversity include methodological and environmental sources of variation.

A targeted phylogenetic approach helps explain New World functional diversity patterns of two eudicot lineages

AbstractAimLarge‐scale functional diversity studies typically examine isolated traits, often without phylogenetic context. Here, we integrate data from five life‐history traits with phylogeny and occurrence records to assess: (a) correlated latitudinal gradients of trait combinations; (b) which traits show phylogenetic conservatism and (c) quantitative, clade‐specific differences in trait syndromes, illustrating the phylogenetic scale of observable variation in ecological strategies.LocationThe Americas.TaxonEricales (Asterids) and Fabales (Rosids).MethodsWe used publicly available trait data sets on height, seed mass, wood density, leaf mass per area (LMA) and growth form, an open‐source phylogeny, and georeferenced occurrence records to investigate functional diversity patterns. We employed phylogenetic generalized least squares and phylogenetic principal components analyses (pPCA) to assess correlated trait evolution and quantify the trait syndrome, respectively. We employed the InfoMap Ecoregions web app to cluster species by bioregions. We used standard statistical tests and randomization simulations to assess statistical significance of results.ResultsEricales and Fabales exhibited a biogeographically consistent, phylogenetically conserved trait syndrome. Moving poleward, species exhibited progressively smaller trait values and more herbaceous and shrubby growth forms (except for LMA, which showed no consistent pattern). We quantified latitudinal variation in this trait syndrome using pPCA, and provide evidence for correlated trait evolution.Main conclusionsWe demonstrate a functional trait syndrome involving height, seed mass, wood density and growth form, but not LMA. Functional trait values showed consistent latitudinal patterns and evidence of correlated evolution, suggesting an underlying ecological strategy. Furthermore, the two clades showed quantitative differences in the manifestation of this trait syndrome. Variation in the syndrome was best observed among species from con‐ordinal families. We interpret this trait syndrome as a strategy of resource acquisition in which habitats with relatively greater soil nutrient content and a shorter growing season favour shorter stature, lower seed mass and wood density, and shrubby or herbaceous growth form.

Spatial Patterns and Drivers of Angiosperm Sexual Systems in China Differ Between Woody and Herbaceous Species.

Plant sexual systems play an important role in the evolution of angiosperm diversity. However, large-scale patterns in the frequencies of sexual systems (i.e. dioecy, monoecy, and hermaphroditism) and their drivers for species with different growth forms remain poorly known. Here, using a newly compiled database on the sexual systems and distributions of 19780 angiosperm species in China, we map the large-scale geographical patterns in frequencies of the sexual systems of woody and herbaceous species separately. We use these data to test the following two hypotheses: (1) the prevalence of sexual systems differs between woody and herbaceous assemblies because woody plants have taller canopies and are found in warm and humid climates; (2) the relative contributions of different drivers (specifically climate, evolutionary age, and mature plant height) to these patterns differ between woody and herbaceous species. We show that geographical patterns in proportions of different sexual systems (especially dioecy) differ between woody and herbaceous species. Geographical variations in sexual systems of woody species were influenced by climate, evolutionary age and plant height. In contrast, these have only weakly significant effects on the patterns of sexual systems of herbaceous species. We suggest that differences between species with woody and herbaceous growth forms in terms of biogeographic patterns of sexual systems, and their drivers, may reflect their differences in physiological and ecological adaptions, as well as the coevolution of sexual system with vegetative traits in response to environmental changes.

Assessment of alpine summit flora in Kashmir Himalaya and its implications for long-term monitoring of climate change impacts

In an era of climate change, the availability of empirical data on alpine summit vegetation in the Himalaya is still scarce. Here we report the assessment of alpine summit flora in Gulmarg Wildlife Sanctuary, Kashmir Himalaya. We employed a globally standardized Multi-Summit Approach and four spatially isolated summits spanning an elevation gradient of 210 m (between 3530–3740 m a.s.l.) from natural treeline to nival zone were studied. Sampling of the summits was carried out in the year 2018 to collect floristic data together with records of soil temperature. A total of 142 vascular plant species were recorded in the sampled summits. Majority of the species were of herbaceous growth form and with perennial life span. Based on Raunkiaer’s life form, hemicryptophytes were the most dominant followed by therophytes and phanerophytes. The summit flora showed the predominance of narrow-endemic species, with broad- and non-endemics declining with elevation. A significant relationship between growth form, Raunkiaer’s life form, and the degree of endemism with elevation was observed. Both species diversity and soil temperature showed a monotonic decrease with increasing elevation. Interestingly, soil temperature clearly determined the magnitude of species diversity on the summits. Furthermore, based on floristic composition, the lowest summit had the highest dissimilarity with the rest of the summits. The present study employed globally standardized protocol to scientifically assess the patterns of plant diversity on the alpine mountain summits of Kashmir Himalaya, which in turn has wide implications towards long-term monitoring of climate change impact on alpine biodiversity in the rapidly warming Himalaya.

Disentangling the influence of ecological and historical factors on seed germination and seedling types in a Neotropical dry forest.

In tropical dry forests, although seed germination and seedling establishment are in general limited by the seasonal availability of water, high interspecific variability, nonetheless, exists in terms of seedling traits and germination dynamics. Differences among species in seed germination and seedling traits may be related to other plant life-history traits, such that assessing these relationships may increase our understanding of factors influencing plant establishment, which would affect the regeneration pathways of tropical dry forest communities. In this study, taking into consideration the effect species' phylogeny, we evaluated the relationships of seed germination metrics (percentage, lag time, and rate of germination) and seedling types (i.e. cotyledons functional morphology), with plant life-history traits (growth form, seed mass, dispersal syndrome and dispersal phenology) for 110 species in a Neotropical dry forest in Mexico. A total of 92% of the species studied disperse their seeds during the dry season, mainly at the beginning of this season (66%), a strategy mostly associated with autochorous herbs. Seed germination was more frequent in species that dispersed seeds at the end of the dry season. Germination percentage was not related to any of the traits studied. However, germination lag time and rate were negatively related to seed mass, a trait that in turn depended on growth form and dispersal syndrome. The dominant seedling type in the community was phanerocotylar epigeal with foliaceous cotyledons (56%), which was mostly associated with small seed mass and herbaceous growth form. Our results provide evidence that several plant life-history traits explain an important part of the variation in seed germination and seedling characteristics observed among species. Therefore, these plant life-history traits may be useful for grouping species in terms of their establishment strategies and roles on the regeneration of tropical dry communities.

Floristic diversity, biological spectrum of lower Tanawal, KP, Pakistan

Field surveys were carried out to evaluate the floristic diversity and biological spectrum of Lower Tanawal, District Abbottabad in different seasons during 2016-2018. This study area was divided into 80 stands on the basis of physiognomy of the vegetation. Life form classes and leaf spectra were classified following Raunkiers methodology. In total, 286 plant species belonging to 86 families were recorded, out of which herbaceous growth form dominated the study area with 187 species, followed by shrub with 54 species. Among all 86 families, Asteraceae was found to be the most dominant family with 25 species, followed by Fabaceae with 24 species and Rosaceae with 20 species. Based on life form classes, Therophytic life form was the leading class with 113 species (39.5104%), followed by Nanophanerophytes with 45 species (15.7342%). In leaf size spectra, Microphylls dominated the flora with 88 species (30.7692%), followed by Mesophyll with 81 species (28.3216%). This study shows the complete floristic composition that may be important as reference work for future ethnobotanical, ecological and conservational studies.

Floristic inventory and biological spectra of Balakot, District Mansehra, Pakistan

This study was conducted to assess the floristic composition, biological spectra and phenology of Tehsil Balakot. Frequent visits were made in different seasons during 2012–13. Field notebook was used to record the data within field. Biological spectrum and leaf sizes classes were determined. The floristic diversity revealed 228 plant species belonged to 184 genera and 72 families. Asteraceae family contributed maximum number of species (27) followed by Rosaceae (18), Apiaceae and Lamiaceae (12) species each, Papilionaceae (11) species while remaining 67 families contributed less than 10 species. Herbaceous growth form was the most leading one (71%), followed by shrub (15%) and tree (14%), respectively. Biological spectrum revealed that hemicryptophytes (32.45%) were the most prevalent, followed by therophytes (31.57%), nanophanerophytes (15.35%), megaphanerophytes (13.59%) and chamaephytes (4.38%). Leaf spectra showed that microphyll (28.94%) were dominant, followed by nanophyll (27.19%), leptophyll (22.80%), mesophyll (14.03%) and megaphyll (7.01%). The flora was influenced by two flowering seasons i.e. March to August and September to February. In the first spell, 193 species were recorded, of these 15.54% trees, 15.02% shrubs, 63.21% herbs, 3.62% grasses and 2.59% ferns; while in the second spell, there were 35 species having 2.85% trees, 17.14% shrubs, 74.28% herbs, and 5.71% grasses. The flowering data shows that June and July were the utmost flowering months with 28.50% in 65 and 20.17% in 46 plant species.