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Because reactive oxygen species are involved in the regulation of biological rhythms, we hypothesized that intra-annual variability of seed progeny quality at low doses of ionizing radiation (LDIRs) would differ from that of background plants. We conducted 12 consecutive experiments using the roll culture method by germinating seeds (monthly for 3 weeks) of six herbaceous plant species (Bromus inermis, Geum aleppicum, Plantago major, Rumex confertus, Silene latifolia, and Taraxacum officinale) growing under conditions of chronic radiation in the East Ural Radioactive Trace (EURT). We assessed physiological (seed viability and abnormality frequency) and biochemical (low-molecular-weight antioxidants, LMWAs) parameters of seedlings. Total absorbed dose rates of maternal plants (TADRplants) and seed embryos (TADRseeds) in the EURT exceeded background levels by 1–3 and 1–2 orders of magnitude, respectively. Nonlinear dependencies on TADR were mainly characteristic of physiological and biochemical parameters. For most populations of the studied species (B. inermis, G. aleppicum, R. confertus, and S. latifolia), seedling survival and root length decreased in the autumn–winter period, while the frequency of abnormal seedlings increased. The content of LMWAs could be ranked as R. confertus > B. inermis > G. aleppicum > S. latifolia, in good agreement with the presence of anthocyanin pigmentation in the plants. The lowest synthesis of antioxidants in seedlings was observed in winter. A high LMWA content promoted growth and reduced the frequency of abnormal seedlings. These results underscore a multistage nature of the impact of LDIRs on intra-annual biological rhythms in plants. High heterogeneity in reference group 'wild grasses' and diversity of their radiobiological effects should help to develop methods of radiation protection for natural ecosystems and facilitate approaches used by the International Commission on Radiological Protection. Absorbed dose rates for six plant species in the East Ural Radioactive Trace (EURT) area range from 0.11 to 73.89 µGy h−s (plants) and 0.11 to 6.88 µGy h−s (seed embryos). Intra-annual rhythms of physiological and biochemical parameters in the EURT zone differ from those in background seedlings. Plants in the EURT area exhibit a wide range of trait variability, asynchrony of the manifestation of the effects, nonlinear dose–response relations, and hormesis. A high content of low-molecular-weight antioxidants (LMWAs) is associated with low frequency of developmental abnormalities and high viability of seed progeny. [ABSTRACT FROM AUTHOR]

The Lamiaceae family comprises herbaceous to woody plants that can thrive in a wide range of habitats and are cosmopolitan in distribution. In Turkey, there are 45 genera and 586 species belonging to the Lamiaceae family. Among these species, 239 taxa are endemic, making it the third-largest family in Turkey in terms of endemic individuals. In this study, seeds of three species from the Lamiaceae family, Izmir oregano (Origanum onites L.), French lavender (Lavandula stoechas L.), and basil (Ocimum basilicum L.), were used as test materials. The research aimed to overcome heterogeneous and low germination issues observed in these seeds, which were determined to be seed-related through preliminary studies, and to achieve the highest germination percentage and average germination time. Various pre-sowing treatments were applied to improve the germination performance and quality of Izmir oregano, French lavender, and basil seeds. For this purpose, the effects of treatments including control, KNO3, GA3, polymer coating, priming, priming + polymer coating, priming + polymer coating + KNO3, and priming + polymer coating + GA3 on seed germination rate and average germination days were investigated in comparison to the control. Prior to the treatments, molecular analyses were conducted on all seed samples to detect viral agents. As a result of the research, the highest germination percentage of 94% was found in Izmir oregano with the priming + polymer coating + KNO3 treatment. In contrast, for French lavender and basil seeds, the germination performance with a 92% and 94% germination rate, respectively, was achieved with the priming + polymer coating + GA3 treatment. Molecular analyses conducted on seed samples did not detect any viral agents. [ABSTRACT FROM AUTHOR]

Kobresia is a subfamily of Cyperaceae, a perennial herbaceous plant that stores a large amount of organic carbon and nutrients (nitrogen, phosphorus, etc.) in the soil. This type of grass is soft and appreciated by all kinds of farm animals. It is one of the predominantly excellent fodder on the Qinghai–Tibet Plateau. Its good growth plays an important role in developing the local economy and maintaining ecological balance on the Qinghai–Tibet Plateau as well. The main objectives of this review are to systematically present and analyze the factors responsible for the low germination rate of Kobresia and to analyze the physical and chemical methods that are used in order to alleviate dormancy and to improve the germination rate of Kobresia seeds. This is performed in order to lay the foundation for future research in this field. At the same time, we have analyzed the research deficiencies and formulated recommendations for the future. This review will provide comprehensive information in order to reduce the cost of planting Kobresia, as well as to provide theoretical support and technical guidance for the purposes of ecosystem restoration and livestock development. [ABSTRACT FROM AUTHOR]

To date, the use of liquid nitrogen (LN) in plant gene banks is relatively limited. Globally, in 2021, approximately 10,000 accessions were cryopreserved, and their explants were derived from in vitro plants. In Europe, out of 500 banks, only 20 use cryogenic temperatures to store plant germplasms. The implementation of seven conservation projects in Poland starting in the 1990s meant that the gene banking system in this country began to gradually develop. Plant gene bank is mainly based on the collection of seeds and makes little use of plant tissues, including those from in vitro culture. From the point of view of systematics, plant material belonging to spermatophytes dominates in Polish gene banks, while spore plants are rarely represented. This review represents the first summary of gene cryobank activities and resources in Poland. It contains a brief overview of the ex situ plant protection programs aimed at the use of LN and presents the characteristics of four existing gene cryobanks in this country. Special attention is devoted to the presentation of studies on the cryopreservation of seeds, as well as of plant tissues, such as embryonic axes and plumules of trees, and fern gametophytes, that make a permanent contribution to gene bank resources.

Accurate tracking of seed dispersal is critical for understanding gene flow and seed bank dynamics, and for predicting population distributions and spread. Available seed-tracking techniques are limited due to environmental and safety issues or requirements for expensive and specialized equipment. Furthermore, few techniques can be applied to studies of water-dispersed seeds. Here we introduce a new seed-tracking method using safranine to stain seeds/fruits by immersing in (ex situ) or spraying with (in situ) staining solution. The hue difference value between pre- and post-stained seeds/fruits was compared using the HSV color model to assess the effect of staining. A total of 181 kinds of seeds/fruits out of 233 tested species of farmland weeds, invasive alien herbaceous plants and trees could be effectively stained magenta to red in hue (320-360°C) from generally yellowish appearance (30-70°C), in which the other 39 ineffectively-stained species were distinguishable by the naked eye from pre-stained seeds. The most effectively stained seeds/fruits were those with fluffy pericarps, episperm, or appendages. Safranine staining was not found to affect seed weight or germination ability regardless of whether seeds were stained ex situ or in situ. For 44 of 48 buried species, the magenta color of stained seeds clearly remained recognizable for more than 5 months after seeds were buried in soil. Tracking experiments using four species (Beckmannia syzigachne, Oryza sativa f. spontanea, Solidago Canadensis, and Acer buergerianum), representing two noxious agricultural weeds, an alien invasive plant, and a tree, respectively, showed that the safranine staining technique can be widely applied for studying plant seed dispersal. Identifying and counting the stained seeds/fruits can be executed by specially complied Python-based program, based on OpenCV library for image processing and Numpy for data handling. From the above results, we conclude that staining with safranine is a cheap, reliable, easily recognized, automatically counted, persistent, environmentally safe, and user-friendly tracking-seed method. This technique may be widely applied to staining most of the seed plant species and the study of seed dispersal in arable land and in disturbed and natural terrestrial or hydrophytic ecological systems. [ABSTRACT FROM AUTHOR]

Background and Aims European mesic meadows are semi-natural open habitats of high biodiversity and an essential part of European landscapes. These species-rich communities can be a source of seed mixes for ecological restoration, urban greening and rewilding. However, limited knowledge of species germination traits is a bottleneck to the development of a competitive native seed industry. Here, we synthesize the seed ecology of mesic meadows. Methods We combined our own experimental data with data obtained from databases to create a combined dataset containing 2005 germination records of 90 plant species from 31 European countries. We performed a Bayesian meta-analysis of this dataset to test the seed germination response to environmental cues including scarification, stratification, temperature, alternating temperature and light. We also used multivariate ordination to check the relationship between seed traits (germination and morphology) and species ecological preferences, and to compare the seed ecology of mesic meadows with that of other herbaceous plant communities from the same geographic area. Key Results The seed ecology of mesic meadows is characterized by (1) high seed germinability when compared with other herbaceous plant communities; (2) low correspondence between seed traits and species ecological preferences; and (3) a deep phylogenetic separation between the two major families, Poaceae and Fabaceae. Poaceae produce many light seeds that respond to gap-detecting germination cues (alternating temperatures and light); Fabaceae produce fewer heavy seeds, which need scarification to break their physical dormancy. Conclusions High germinability of meadow seeds will reduce their capacity to form persistent seed banks, resulting in dispersal limitations to passive regeneration. For centuries, human activities have shaped the regeneration of meadows, leading to a loss of seed dormancy and decoupling seeds from seasonal cycles, as has been found in many domesticated species. The same anthropic processes that have shaped semi-natural mesic meadows have left them dependent on continued human intervention for their regeneration, highlighting the importance of active restoration via seed supply. [ABSTRACT FROM AUTHOR]

Background: Pennycress (Thlaspi arvense L.) is an annual herbaceous plant of the Cruciferae family that has attracted attention as an oil crop and interseeded cover crop. We collected seeds of pennycress from five provenances in Northeast China, compared their characteristics, i.e. oil content, fatty acid composition, physical, chemical and antioxidant properties, their correlations with environmental factors were also analysed. Results: There were significant differences in the seed characteristics, oil content, quality indicators and composition among different provenances (P < 0.05). The 1000-seed weight ranged from 0.80 to 1.03 g; seed oil content from 28.89 to 42.57%; iodine from 79.19 to 99.09; saponification value from 186.51 to 199.60; peroxide value from 0.07 to 10.60; and acid value from 0.97 to 13.02. The range of seed oil colours were 66.53–78.78 (L*), 4.51–10.29 (a*), and 105.68–121.35 (b*). Erucic acid (C22:1) was the fatty acids with the highest content in pennycress seed oils (31.12–35.31%), followed by linoleic acid (C18:2 16.92–18.95%) and α-linolenic acid (C18:3 14.05–15.34%). The fatty acid 8,11,14-eicosatrienoic acid (C20:3) was detected for the first time in seed oils from Beian city, Panshi city and Kedong county, with contents of 1.13%, 0.84% and 1.03%, respectively. We compare and report for the first time on the radical-scavenging activity of the seed oils of pennycress. The EC50 values of the DPPH radical-scavenging activity and ABTS+ radical-scavenging activity of the seed oils from different provenances were 8.65–19.21 mg/mL and 6.82–10.61 mg/mL, respectively. The ferric ion reduction antioxidant capacity (FRAP) ranged from 0.11 to 0.30 mmol Fe2+/g, which is equivalent to 4 mg/mL FeSO4 of pennycress seed oils. Conclusions: There was a significant correlation between seed characteristics and changes in geographical factors. With increasing longitude, the thickness of seeds, 1000-seed weight, and seed oil content increased, while the acid and peroxide values of the seed oil decreased. As the latitude increased, the 1000-seed weight and seed oil content increased, while the seed oil peroxide value decreased. Furthermore, mean annual temperature and annual rainfall are the two key environmental factors affecting the quality of pennycress. [ABSTRACT FROM AUTHOR]

To date, the use of liquid nitrogen (LN) in plant gene banks is relatively limited. Globally, in 2021, approximately 10,000 accessions were cryopreserved, and their explants were derived from in vitro plants. In Europe, out of 500 banks, only 20 use cryogenic temperatures to store plant germplasms. The implementation of seven conservation projects in Poland starting in the 1990s meant that the gene banking system in this country began to gradually develop. Plant gene bank is mainly based on the collection of seeds and makes little use of plant tissues, including those from in vitro culture. From the point of view of systematics, plant material belonging to spermatophytes dominates in Polish gene banks, while spore plants are rarely represented. This review represents the first summary of gene cryobank activities and resources in Poland. It contains a brief overview of the ex situ plant protection programs aimed at the use of LN and presents the characteristics of four existing gene cryobanks in this country. Special attention is devoted to the presentation of studies on the cryopreservation of seeds, as well as of plant tissues, such as embryonic axes and plumules of trees, and fern gametophytes, that make a permanent contribution to gene bank resources. [ABSTRACT FROM AUTHOR]

Peganum harmala L., known as Harmal or African, Syrian Rue, Espand (in Iranian culture), and Ozallaik (in Turkey), is a perennial herbaceous glabrous plant, which offers many antimicrobial activities in indoor air. In this regard, in the present study, we aimed at evaluating the disinfectant effects of Peganum harmala L. (PHL) seed smoke on microbial load in air. For this reason, the effects of four doses of PHL seeds (5, 10, 15, and 20 g) and various sampling times in the range of 0–30 min were examined on its antibacterial and antifungal effects. The experiments were conducted at two different areas including a classroom located at the health faculty of Ahvaz University of Medical Sciences and a residential area with a similar volume of 60 m3. Tryptic soy agar (TSA) was applied as a specific bacterial culture medium, and sabouraud dextrose agar (SDA) was used as a specific fungal culture medium. The concentration of bacteria and fungi in the indoor air of the residential area decreased by 71.4 and 94.7%, respectively. In the educational area, the concentration of bacteria and fungi decreased by 92.8 and 88.9%, respectively. In conclusion, the PHL smoke showed antibacterial and antifungal effects, which may be due to its alkaloids harmine properties, while it causes an increase in the concentration of particles in the air of indoor environments. Therefore, it can be used as an indoor air disinfectant for decreasing the load of bacteria and viruses in a closed space. [ABSTRACT FROM AUTHOR]

Maternal care is one of the key fitness parameters in all organisms. In plants, maternal care takes the form of seeds production. Although seed mass is the most studied proxy for this maternal provision due to its correlation with the overall amount of nutrients, this proxy does not take into account seed nutrient contents and the proportions of light‐dependent resources (C) and soil‐dependent resources (N and P), which can strongly affect seedling establishment and survival. We tested the hypothesis that seed nutrient contents is fine‐tuned to the expected conditions of seed germination, namely, that seeds of plants from light‐limited conditions will have proportionally more carbon than those of plants that are not light‐limited and vice versa. We used a phylogenetically informed comparative approach with 510 central European herbaceous species to examine relationships between proportions of N, P and nonstructural C, and the environment in which their seedlings typically germinate. We showed that, in spite of the strong phylogenetic signal in nutrient contents, proportions of N and nonstructural C vary according to our hypothesis, i.e. seeds are primarily provided with nutrients expected to be limiting in a given environment. Namely, the proportion of nonstructural C in seeds was higher in species from nutrient‐rich habitats. This enables seedlings to develop independent resource‐acquiring organs quickly. We demonstrated that seed nutrient contents depends on seed mass; namely, the proportion of P out of the total seed mass was higher in small seeds, and the proportion of unusable structural C was higher in large seeds. Our results suggest that seed nutrient content is under selection driven by both seed mass and the environment in which seedlings are likely to germinate. It means that seed nutrient content is a seed trait of clear ecological relevance and hence deserves much closer attention. [ABSTRACT FROM AUTHOR]

Seed dispersal by ants is an important means of migration for plants. Many myrmecochorous plants have specialized appendages in their seeds called elaiosome, which provides nutritional rewards for ants, and enable effective seed dispersal. However, some nonmyrmecochorous seeds without elaiosomes are also dispersed by ant species, suggesting the additional mechanisms other than elaiosomes for seed dispersal by ants. The seeds of the achlorophyllous and myco-heterotrophic herbaceous plant Monotropastrum humile are very small without elaiosomes; we investigated whether odor of the seeds could mediate seed dispersal by ants. We performed a bioassay using seeds of M. humile and the ant Nylanderia flavipes to demonstrate ant-mediated seed dispersal. We also analyzed the volatile odors emitted from M. humile seeds and conducted bioassays using dummy seeds coated with seed volatiles. Although elaiosomes were absent from the M. humile seeds, the ants carried the seeds to their nests. They also carried the dummy seeds coated with the seed volatile mixture to the nest and left some dummy seeds inside the nest and discarded the rest of the dummy seeds outside the nest with a bias toward specific locations, which might be conducive to germination. We concluded that, in M. humile seeds, volatile odor mixtures were sufficient to induce seed-carrying behavior by the ants even without elaiosomes. [ABSTRACT FROM AUTHOR]

Preferences of seed predators may be an important factor that introduces bias in the results of seed predation studies. In this paper, we report on the experimentally established preferences of carabid beetles for seeds of herbaceous plants. The standard arrangement of 28 species of seeds from 13 families was offered to 37 species of carabids belonging to 5 tribes. The overall consumption was affected by the body mass more than by the body length and showed a quadratic relationship with the dry body mass of the carabid. The number of preferred species of seeds varied from 1 to 16, and in unspecialized species the ordered standardized consumptions formed an almost straight line with negative slope, while in specialized to highly specialized species the standardized consumption exponentially declined with increasing order of species. The most preferred seeds were Taraxacum officinale, Capsella bursa-pastoris, Tripleurospermum inodorum and Descurainia sophia, which were preferred by 28, 20, 19 and 19 species of carabids, respectively, while Consolida regalis, Arctia lappa and Bidens tripartita were not preferred by any of the studied carabids. We pinpoint that choice for a model seed species for a seed predation experiment in the field shall reflect the attractiveness of the seed for predators as seed identity may bring bias in the results. [ABSTRACT FROM AUTHOR]

Summary: Herbaceous plants harbour species‐rich communities of asymptomatic endophytic fungi. Although some of these endophytes are entomopathogenic, many are not, and remarkably little is known about how the presence of these fungi in plant tissues affects phytophagous insects.Here we show through a meta‐analysis that both entomopathogenic and nonentomopathogenic endophytes have a negative effect on insect herbivores. Growth and performance of polyphagous and sucking insects are reduced by nonentomopathogenic endophytes, but monophages are unaffected, likely because the latter are better adapted to secondary metabolites produced or induced by the fungi.Furthermore, studies using excised leaves report weaker effects than those with intact plants, likely caused by chemical changes being masked by leaf excision. Most surprisingly, endophyte infection of seeds produces the greatest effect on insect herbivores in subsequent mature plants, even though the usual mode of fungal transmission is infection of leaves by airborne spores.We conclude that these ubiquitous hidden fungi may be important bodyguards of plants. However, in order to fully understand their roles in plant protection, we must be aware that minor differences in experimental design can lead to contradictory results. [ABSTRACT FROM AUTHOR]

Lipnik site 5, from which a storage pit dated to the Middle Bronze Age (ca. 1400–1100) was studied, gave more than 70 plant taxa in the extraordinarily well-preserved charred assemblage. In the paper, a detailed description of selected plants is presented followed by environmental interpretation. Acorns (Quercus) dominated in volume and proso millet (Panicum miliaceum) in the number of specimens. The first large find of that late incomer north of the Carpathian Mountains is presented here. The pit users also used hulled wheat (einkorn, emmer, and spelt); barley; and probably peas. In the pit, a large number of grassland plants were noted accompanied by a very few remains of aquatic (Elatine) and forest herbaceous plants (Astrantia major). Weeds and ruderal plants were also present. The composition of plant remains is very unusual for this type of archeological feature, suggesting a mixed type of food strategy for its users, dominated by plant gathering and animal husbandry. The site is located in a newly settled ecotone zone, on the margin of fertile loess areas and mountain foothills. [ABSTRACT FROM AUTHOR]

The objective of this work was to determine the seed quality of 20 accessions of herbaceous legumes. The seeds were from a collection mission carried out in the Ciego de Ávila province, located in the central region of Cuba. Afterwards a germination test (with seed coat cut) was conducted on all the material in glass Petri dishes with filter paper according to the recommendations made by ISTA. The number of seeds used was variable in each accession and a completely randomized design was used with two and four replicas according to the seed availability. High quality was obtained in the seeds of the accessions Galactea spiciformis (Cruise 1 provenance), Calopogonium caeruleum and Lablab purpureus with 100, 80 and 70%, respectively, which did not occur in Centrosema plumieri, Centrosema molle and Galactea spiciformis (these last two of the Florencia provenance) which did not germinate. Most of the accessions achieved 100% survival in the ones sown in bags as well as in the field of the total accessions that survived, 50% of those planted in bags reached 100%, while 70% of those planted in the field obtained it. The accessions Lablab purpureus, Centrosema plumieri, Centrosema molle and Galactea spiciformis (Florencia provenance) did not survive in one medium or the other. It is concluded that the species Galactea spiciformis and Calopogonium caeruleum (both of the provenance Cruise 1) were the ones that showed the best results regarding the quality of the seeds. [ABSTRACT FROM AUTHOR]

Salvia hispanica L. famous as 'chia' is an annual herbaceous plant belonging to family Labiatae, is a richest source of alpha linolenic fatty acid. A detailed examination on chia seeds was performed. The microscopic investigations showed the presence of lignified fibres, epidermis cells, aleurone grains, fatty oil globules and lignified sclerides etc. Physicochemical assessment of chia seeds revealed foreign organic matter (0.76%), loss on drying (8.09%), pH (4.39), moisture content (8.96%), swelling index (8.36), foaming index (<100), total ash (7.09%), water soluble ash (1.09%), acid insoluble ash (0.48%), sulphated ash (0.94%),relative density (0.892), refractive index (1.462), acid value (1.862), saponification value (194.29), peroxide value (4.680), acetyl value (169.28) and iodine value (74.62). Elemental analysis was performed using atomic absorption spectroscopy various heavy metals (As, Hg, Pb, Cd) and other elements (Cu, Zn, Fe and Mg) all were within limits. Chia seeds crude material as well as its extract showed no microbial contamination. High performance thin layer chromatography fingerprinting profile of chia seeds fixed oil showed the presence of alpha linolenic acid. Work on standardization assumes imperative consequence. However, wide-ranging literature survey on this plant revealed that, more research work is required to update the standardization parameters. Therefore, findings of this study will facilitate quality control and presence of the various phytoconstituents in plant seed. [ABSTRACT FROM AUTHOR]

Floral and seed traits, their relationships, and responses to abiotic constraints are considered the key determinants of the invasion success of non-native plant species. However, studies evaluating the pattern of floral and seed traits of non-native species in mountain ecosystems are lacking. In this study, we determined (a) whether the floral and seed traits of native and non-native species show similarity or dissimilarity across elevations in mountains, and (b) whether the non-native species follow different allometric patterns compared with native species. Functional variations between native and non-native species were assessed through floral and seed traits: flower count, flower display area, flower mass, specific flower area, seed count, and seed mass across an elevational gradient. Permanent plots (20 × 20 m) were laid at each 100 m elevation rise from 2000 to 4000 m a.s.l. for sampling of herbaceous plant species. The mean values of floral and seed traits such as flower display area, specific flower area, and seed count were significantly higher for non-native species compared to native species. A significant difference in trait values (flower display area, flower mass, seed count, and seed mass) between non-native species and native species was observed along the elevational gradient, except for flower count and specific flower area. The bivariate relationship revealed non-native species to exhibit a stronger relationship between flower display area ∼ flower mass, and flower display area ∼ seed mass traits than the native species. Non-native species showed enhanced reproductive ability under varying environmental conditions along an elevational gradient in mountain ecosystems. Greater flower display area and seed mass at lower elevations and a stronger overall trait-trait relationship among non-native species implied resource investment in pollinator visualization, flower mass, and seed quality over seed quantity. The study concludes that enhanced plasticity and reproductive fitness of floral and seed traits would consequently aid non-native species to adapt, become invasive, and displace native species in mountain ecosystems if the climatic barriers acting on non-native species are reduced with climate change. • Studied floral and seed traits of native and non-native species in mountain ecosystems. • Floral and seed traits exhibited significant differences between non-native and native plants. • Bivariate scaling relationships exhibited stronger allometric relationships for non-natives. • Non-natives showed enhanced reproductive ability along an elevational gradient. • Enhanced reproductive traits facilitate non-natives to adapt in mountains. [ABSTRACT FROM AUTHOR]

Research devoted to investigating the relationship between elevation and seed size in alpine plants gives contradictory results. Some studies document a positive correlation between seed size and elevation, whereas in others a negative correlation is reported. We propose a novel approach to the problem by looking at the whole strategy of seed production, including seed number, and by focusing on a range of environmental variables. In the Tatra Mountains (southern Poland), we selected 73 sites at which seeds of six widely occurring mountain herbaceous species were collected. Each site was characterized by 13 parameters that included climatic and physicochemical soil variables. For each parameter, residuals from a linear regression against elevation were calculated and the residuals were used in a factor analysis. The obtained factors, together with elevation, were used as independent variables in a multiple regression analysis. Elevation affected seed size in four species: in two species the correlation was positive, and in two others it was negative. In three species seed number was related to elevation, and the correlation was negative in all cases. Our results indicate that elevation-dependence of seed production is specific to the species and reflects different resource allocation strategies. Diverse correlations of plant characteristics with elevation may also result from area-specific patterns, because different mountain ranges may exhibit different correlations between elevation and environmental factors. Only by attaining a reproductive allocation perspective and thorough assessment of environmental factors, a full understanding of elevational variation in seed size is possible. [ABSTRACT FROM AUTHOR]

Can CSR theory, in conjunction with a recently proposed globally calibrated CSR ordination (“StrateFy”), using only three easily measured leaf traits (leaf area, specific leaf area and leaf dry matter content) predict the functional signature of herbaceous vegetation along experimentally manipulated gradients of soil fertility and disturbance? To determine this, we grew 37 herbaceous species in mixture for five years in 24 experimental mesocosms differing in factorial levels of soil resources (stress) and density-independent mortality (disturbance). We measured 16 different functional traits and then ordinated the resulting vegetation within the CSR triangle using StrateFy. We then calculated community-weighted mean (CWM) values of the competitor (CCWM), stress-tolerator (SCWM) and ruderal (RCWM) scores for each mesocosm. We found a significant increase in SCWM from low to high stress mesocosms, and an increase in RCWM from lowly to highly disturbed mesocosms. However, CCWM did not decline significantly as intensity of stress or disturbance increased, as predicted by CSR theory. This last result likely arose because our herbaceous species were relatively poor competitors in global comparisons and thus no strong competitors in our species pool were selectively favoured in low stress and low disturbed mesocosms. Variation in the 13 other traits, not used by StrateFy, largely argeed with the predictions of CSR theory. StrateFy worked surprisingly well in our experimental study except for the C-dimension. Despite loss of some precision, it has great potential applicability in future studies due to its simplicity and generality. [ABSTRACT FROM AUTHOR]

The article presents analyses supporting the hypothesis that functional differentiation within herbaceous plants is based on dimensions different from those that are used in large-scale studies that include primarily woody species. Topics discussed include tolerance and avoidance as two fundamentally different strategies that plants use to cope with disturbance. Also mentioned are the leaf-height-seed (LHS) system and disturbances select and clonal and bid bank traits in trait-based analyses.

Questions Do shrubs regulate herbaceous plant community by modifying seed and plant distributions at the individual shrub scale? Do the magnitude and extent of effects at this scale change with shrub cover? Location A desert steppe, Mandalgobi, Mongolia. Methods We compared soil properties, seed accumulation and the establishment of plants of three functional types (annual forb, perennial forb and perennial graminoid) between shrub microsites (on mounds vs mound interspace) at sites differing in shrub coverage (high and low). Results Shrub patches (a legume Caragana microphylla) promoted seed accumulation but inhibited plant establishment on mounds, relative to the mound interspace, for all functional types. However, the effects varied with shrub cover, particularly in the mound interspace, with responses specific to each functional type. The accumulation of soil and annual forb seeds increased with shrub cover at both microsites. Additionally, the density of annual forbs was positively related to shrub cover in the mound interspace. In contrast, the density of perennial forbs and graminoids decreased with increasing shrub cover at both microsites, possibly because of enhanced sand accumulation. Conclusion Shrubs shape herbaceous plant community by causing differences at the individual shrub scale in seed and plant distributions. Additionally, we showed that individual shrub effects are shrub cover-dependent: dense shrub stands enhanced the dominance of annual forbs in spite of the negative effect found at the individual shrub scale, whereas perennial forbs and graminoids were less abundant in denser shrub stands. Shrubs can play an important role in structuring plant communities via shrub cover-dependent variation at microsites. [ABSTRACT FROM AUTHOR]