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To examine the effects of the recent Acmella radicans invasion on plant community and diversity in invaded habitats, the composition, density, species richness, diversity indices, and evenness index of the soil seed bank community of two different habitats (wasteland and cultivated land) in Yunnan Province, China, were analyzed through field sampling and greenhouse germination tests. A total of 28 species of plants belonging to 15 families and 28 genera, all annual herbs, were found in the soil seed bank. Seed densities and species number in the seed bank tended to be greater in April than in October; cultivated land also featured higher seed densities and species numbers compared to wasteland. With increased A. radicans cover, the seed bank population of A. radicans also significantly increased, but the seed bank populations of many other dominant species (e.g., Ageratum conyzoides and Gamochaeta pensylvanica) and native species (e.g., Laggera crispata and Poa annua) clearly declined. The germination of A. radicans seeds was concentrated during the period from the 4th to the 5th weeks. Vertically, the seed number of A. radicans was significantly different among the 0–5 cm, 5–10 cm and 10–20 cm layers that accounted for 80.7–90.6%, 9.4–16.1% and 0.0–3.2% of the total seed density in wasteland, respectively; and in cultivated land, A. radicans accounted for 56.8–64.9%, 26.7–31.8% and 8.1–13.5% of the total seed density, respectively. With reduced A. radicans cover, the species richness, Simpson index, Shannon–Wiener index, and Pielou indices of the weed community generally increased, and most diversity indices of weed communities in cultivated land were lower than in wasteland under the same cover of A. radicans. The results indicate that the invasion of A. radicans has negatively affected local weed community composition and reduced weed community diversity, and that these negative impacts in cultivated land may be enhanced by human disturbance. Our study was the first to elucidate the influence of A. radicans invasion on soil seed bank community characteristics in invaded habitats, providing a better understanding of its invasion and spread mechanisms in order to aid in developing a scientific basis for the prevention and control of this invader. [ABSTRACT FROM AUTHOR]

As a key component of the ecosystem, soil seed banks (SSBs) play a vital role in the evolution and renewal of plant communities. Although the pattern and mechanisms of influence of SSBs along the altitudinal gradient have been reported, most studies have focused on forest, grassland and alpine meadow ecosystems. The pattern and factors of SSBs across the altitudinal gradient in sedge peatlands remain largely unknown. Through vegetation surveys and seed germination experiments, we studied the changes in aboveground vegetation and SSBs in sedge peatlands at altitudes ranging from 300 m to 1300 m in the Changbai Mountains, China, and discussed the direct and indirect effects of climatic factors, soil properties and aboveground vegetation on SSBs. The results showed that the richness and density of the SSBs of sedge peatlands decreased with the altitude. Similarly, aboveground vegetation richness and density declined with altitude. A Spearman correlation analysis showed that SSB richness and density were mainly correlated with mean annual temperature, soil total phosphorus and ammonia nitrogen and the plant composition and richness of aboveground vegetation. A structural equation model analysis showed that climatic factors and aboveground vegetation directly affected seed bank richness, while soil properties indirectly affected it by directly affecting aboveground vegetation. Climatic factors, soil properties and aboveground vegetation directly affected SSB density, and soil properties indirectly affected it by directly affecting aboveground vegetation. This finding enhances our understanding of the altitude patterns of the SSBs in sedge peatlands and the response to future climate and environmental changes. [ABSTRACT FROM AUTHOR]

Understanding the modulating effect of environmental conditions on the germination of seeds constituting a persistent soil seed bank has both theoretical and practical merits. I studied the role of precipitation in the germination of seeds of the imperiled geophyte Iris atrofusca , which exhibits strong seed dormancy and intermittant germination over years. I wanted to know how a single significant rain event in one of the first several seasons after seed maturation and dispersal can affect seed germination and seedling growth in I. atrofusca. This is important because knowing the amount and time of such a rainfall event, one can imitate it by a single watering applied to an artificial soil seed bank, thus initiating or substantially increasing seed germination and improving seedling growth and therefore survival. Overall, the results imply that the most efficient in terms of both seed germination and seedling survival is supplementary irrigation equivalent to 40 mm rainfall applied as a single rain event to the artificial soil seed bank early in the first and second season, plus watering equivalent to 20–40 mm in the months when the amount of precipitation is low (below 20 mm) not only in the first and second, but also in subsequent seasons. [ABSTRACT FROM AUTHOR]

Background: Phytogenic mounds are a type of microtopography formed under perennial plants canopies in water erosion areas. However, the function of phytogenic mounds in seed assemblages and their ecological consequences remain poorly understood in semiarid areas with water erosion. Thus, understanding the characteristics of seed banks on mounds is crucial for ecosystem conservation and management in water-eroded areas. Methods: We compared the quantity and composition of soil seed banks on the upslope and downslope parts of mounds and intercanopy surfaces along four slope gradients. We also explored the relationships among the soil seed bank, aboveground vegetation, and environmental factors. Furthermore, the species similarity between the soil seed bank and aboveground vegetation was analyzed to clarify the important ecological consequences of phytogenic mounds for plant community construction in serious soil erosion area. Results: For slopes with a = 46.6%, the intercanopy surfaces had greater soil seed bank species composition, density, and diversity than did the phytogenic mounds, and these characteristics showed no significant differences between the upslope and downslope parts of the mounds. As the slope increased, the soil seed bank density and species composition increased on the upslope part of the mound, and reached a maximum for slopes with a > 70%, while the downslope part of the mound negatively effected on seed aggregation. The sediment accumulation rate, soil moisture, particle size distribution, pH, organic matter carbon, and hardness were significantly correlated with the soil seed bank density and diversity in the study area. For slopes with 0 < a = 26.8%, the species similarity coefficient between the soil seed bank and aboveground vegetation was the highest for the intercanopy surface. This species similarity on the upslope part of the mound showed an increasing trend with increasing slope gradient, while the downslope part of the mound had the opposite trend. For slopes with a > 70%, the upslope part of the mound did not only have more species in the soil seed bank but also had more species in aboveground vegetation than did the downslope part of the mound and intercanopy surface. Conclusion: For slopes with a = 46.6%, phytogenic mounds had barely impact soil seed bank accumulation and conservation in semiarid and eroded areas. For slopes with a > 46.6%, the mounds (particularly on the upslope part of the mound) showed seed assemblage functions, which are coupled with improving edaphic conditions and decreasing microhabitat stress; thus, phytogenic mounds, or areas of microtopography, can be used to promote restoration success in semiarid eroded areas. [ABSTRACT FROM AUTHOR]

The soil seed bank (SSB) and soil microbial communities are among the most crucial drivers of belowground biodiversity in grasslands. Changes in components of soil biodiversity following protection from grazing were observed in cold, semiarid grasslands. To study these changes, soil samples were taken in an intensively grazed area and in an exclosure established 20 years prior to this study. In particular, changes in biodiversity components such as SSB and microbial activities in two soil depths (0–5 and 5–10 cm) were measured. Nonmetric dimensional scaling showed that after grazing removal, the SSB had changed. SSB density, richness, and diversity were higher in the ungrazed plots. The increase in SSB density and diversity in the exclosure may have been caused by the absence of direct adverse effects of grazing on the SSB, like trampling and plant consumption, or by reduced indirect effects, such as seed germination facilitation in canopy gaps created by grazing animals. The effect of grazing removal on basal respiration, substrate‐induced respiration, and urease activity was highly significant (p < 0.01) and may be due to an increase in soil moisture after grazing exclusion. The effect of grazing removal on soil biological parameters was greater in the upper layer than in the deeper soil layer. This study shows that grazing exclusion can be a useful approach in restoring components of soil biodiversity. [ABSTRACT FROM AUTHOR]

We tested the hypothesis that the number of seedlings from the soil seed bank (SSB) in forests polluted by heavy metals and disturbed by recent fires decreases. It was also assumed that the consequences of pollution and fires for the soil seed bank are additive. We estimated the number of seedlings from the SSB of pine forests located near the Karabash copper smelter (KCS) (contaminated by Cu, Zn, Pb, and Cd) and from uncontaminated forests of the Ilmen State Reserve (ISR). In both areas, samples of the forest litter and humus horizon were taken from forests recently exposed to ground fires and long-term unburned forests. Samples were exhibited from June to September, conducting seven rounds of counting seedlings. Small peculiarities of the emergence of seedlings on the samples of the forest litter and the humus horizon were established. However, the regularities of the reaction of SSB to pollution and fire disturbances did not depend on the soil horizon. The number of seedlings on substrates from contaminated forests was 5–8 times lower than the number of seedlings on substrates from background forests. A decrease in the number of seedlings on polluted substrates was accompanied by an increase in the share of dicots in the total number of seedlings. The relationship between the number of seedlings and the age of fires was not found. The additivity of the consequences of pollution and fires has also not been established. Of the two types of damage, pollution and fires, the pollution factor is of leading importance for SSBs. The results indicate a low recovery capacity of the herb-shrub layer of polluted forests. [ABSTRACT FROM AUTHOR]

Abstract [Objective] The study aims to investigate the soil seed bank and seedling regeneration characteristics of Amygdalus ledebouriana in Xinjiang, and to explore the limiting factors affecting the population regeneration of A . ledebouriana. [Methods] A . ledebouriana in the Ta􀆳e Basin of Xinjiang was used as the research object, and the soil seed bank and seedling regeneration were studied by means of field plot investigation, soil sample collection, and seedling number and grade statistics under the mother plant. [Results] (1) The average density of seeds in the soil seed bank of A . ledebouriana was 96.45 m2. The complete seed density of the Tuoli population was the highest, and the density of seeds eaten by the Yumin population was the highest, while the insect-eaten seeds only appeared in the Tacheng population. (2) The seeds of A . ledebouriana were mainly distributed in the litter layer, accounting for 56.29% of the total seeds, S2 (0-5 cm) soil layer accounted for 29.07%, and S3 (5-10 cm) soil layer accounted for 14.65%. The horizontal diffusion distance of soil seeds was proportional to the slope of A . ledebouriana. (3) No seedlings were found in the investigated A . ledebouriana seedlings. Grade Ⅰ seedlings accounted for 51.12% of the total number of seedlings. A . ledebouriana seedlings were concentrated in the range of 50 cm from the base of the mother plant. [Conclusion] The distribution characteristics of soil seed bank of A . ledebouriana is near the mother plant and the surface, and the characteristics of seedling regeneration is also near the mother plant distribution. Under natural conditions, gnawed seeds, insect-infested seeds, and niche loss are the main reasons why A . ledebouriana seedlings cannot germinate and the regeneration of seedlings is limited.

The rare and threatened Heliosciadium repens grows in moist grasslands and has a distinct life cycle. Plants reproduce both clonally, although ramets tend to be short‐lived, and sexually, with seeds that can form a persistent soil seed bank. The germination requirements of H. repens were investigated, yielding important information for its habitat management and conservation. We examined the soil seed bank in three populations and carried out germination experiments and embryo growth measurements with fresh seeds in laboratory, greenhouse and outdoor conditions. We also investigated the effects of storage and burial of seeds. H. repens formed a long‐term persistent (>6 years) soil seed bank with very pronounced primary dormancy, but no secondary dormancy or dormancy cycles. Seeds can germinate throughout the growing season when temperatures are sufficiently high. Embryo growth and seed germination are triggered by light and, to a lesser extent, daily temperature fluctuations. Seeds of H. repens seem to have developed a unique germination syndrome with several strategies to remain dormant in the soil until optimal conditions are present for seedling establishment and survival. Both sexual reproduction and seed bank formation are crucial for the long‐term survival of the populations. [ABSTRACT FROM AUTHOR]

Context: The concept of the fire regime is central to understanding and managing fire-prone ecosystems globally, and information on past regimes can provide useful insights into species disturbance adaptations. Although observations from satellite imagery or palaeoecological proxy data can provide direct evidence of past, pre-colonial fire regimes, they may be limited in temporal or spatial resolution and are not available for all ecosystems. However, fire-related plant-trait and demographic data offer an alternative approach to understand species–fire regime associations at the ecosystem scale. Aims: We aimed to quantify the life-history strategies and associated fire regimes for six co-occurring shrub and tree species from fire-prone, Mediterranean-climate Banksia Woodlands in south-western Australia. Methods: We collected static demographic data on size structure, seedling recruitment, and plant mortality across sites of varying time since last fire. We combined demographic data with key fire-related species traits to define plant life-history strategies. We then compared observed life histories with a priori expectations for surface, stand-replacing, and mixed-severity fire-regime types to infer historical fire-regime associations. Key results: Fire-killed shrubs and weakly serotinous trees had abundant post-fire seedling recruitment, but also developed multi-cohort populations during fire-free periods via inter-fire seedling recruitment. Resprouting shrubs had little seedling recruitment at any time, even following fire, and showed no signs of decline in the long absence of fire, likely owing to their very long lifespans. Conclusions: The variation in life-history strategies for these six co-occurring species is consistent with known ecological strategies to cope with high variation in fire intervals in a mixed-severity fire regime. Whereas resprouting and strong post-fire seedling recruitment indicate a tolerance of shorter fire intervals, inter-fire recruitment and weak serotiny are interpreted as a bet-hedging strategy to cope with occasional long fire-free periods that may otherwise exceed adult and seed-bank lifespans. Implications: Our findings suggested that Banksia Woodlands have evolved with highly variable fire intervals in a mixed-severity fire regime. Further investigations of species adaptations to varying fire size and patchiness can help extend our understanding of fire-regime tolerances. Information on past fire regimes can provide useful insights into species disturbance adaptations. To test the idea that contemporary demographic parameters provide a signature of past fire regimes, we assessed fire-related plant life-history strategies by using static demographic data collected along a 1–35-year fire-age chronosequence for species with a variety of traits. Species displayed a collection of life-history strategies associated with a historical mixed-severity fire regime, including adaptations for short and long fire intervals, interacting with varying fire severity. Photograph by Russell Miller. [ABSTRACT FROM AUTHOR]

Seeds maintained on seed banks are submitted to two conditions of light during discontinuous hydration: presence or absence. We aimed to investigate the influence of light during discontinuous hydration and its relationship with the establishment of the cacti species. We raised two hypotheses: discontinuous hydration increases the longevity of seeds, and the presence and the absence of light during hydration/dehydration cycles (HD cycles) present different benefits in maintaining their viability in the soil seed bank for a longer time. We subjected seeds to HD cycles in the presence and absence of light. After that, we established a soil seed bank and analyzed the germinative behavior and biochemical compounds at intervals of 0, 3, 6, 9, 12, and 15 months. HD cycles prolonged seed longevity, confirming our first hypothesis. Treatments of HD cycles in the darkness provided the maintenance of seed viability for a period longer than 9 months, which corroborates our second hypothesis. HD cycles in the presence of light only favor the germination behavior of fresh seeds. Reducing sugars are consumed during the first months in seeds buried in the soil. However, protein concentration remains higher in seeds not submitted to HD cycles after 12 months. Our study proposes the existence of a "seed dark hydration memory" related to seed longevity and a "seed light hydration memory" related to the germination of fresh seeds. Thus, the response to light incidence during discontinuous hydration represents an important strategy for the reproductive success of positive photoblastic species in their natural environment. [ABSTRACT FROM AUTHOR]

The soil seed bank is one of the most important ecological indicators to evaluate and monitor the ecological restoration process of plant communities. We aimed to analyze the influence of two different ecological restoration techniques on the diversity and floristic composition of the soil seed bank and of standing vegetation, in two 4‐year‐old areas under forest restoration around bauxite mining, Southeast Brazil. A total of 30 soil samples were collected in each area (SPN—forest restoration by seedling planting in rows and nucleation techniques between planting rows and SP—forest restoration by seedling planting in rows). The samples were transported to a shade house and evaluated for 6 months, where germinated individuals were counted and identified weekly. A floristic census of shrub/tree species was conducted to assess the diversity of standing vegetation. The results indicated that the soil seed banks of the two areas are floristically similar (predominance of pioneer, herbaceous, and native origin species). The two restoration techniques did not differ in their effects on the species composition of the soil seed bank, mainly due to the restoration age. However, when analyzing the standing vegetation, 38 species were recorded in SPN, while only 20 species were in SP. This result demonstrates that nucleation techniques contributed to the increase in species diversity in SPN. We conclude that combining seedling planting in rows with nucleation techniques (topsoil transposition, direct seeding, and artificial perches) can enhance species diversity in standing vegetation, improve forest functionality, and consequently enhance the potential for forest restoration. [ABSTRACT FROM AUTHOR]

Several high-elevation plant species would experience an increased risk of regional extinction due to various climatic and anthropogenic factors. Information about the effects of climate change is urgently needed for modeling vegetation dynamics because it influences the various seed parameters like seed germination, seed maturation, seed mass, and seed bank in the soil. The present study was conducted at an elevation of 3145–3560 m in the treeline area of the western Himalayan region of India. The change in seed color is correlated with other seed parameters such as seed moisture content, seed germination, seed mass, and seed fall density. A decline in moisture content in maturing seeds is closely related to seed maturity (p < 0.05). Quercus semecarpifolia contains the highest seed mass followed by Abies spectabilis. Reportedly, the species with higher seed mass have an advantage in light-restricted environments for seed germination and seedling development. In addition, the fruit mass was observed to be the highest for Rhododendron campanulatum, while both Betula utilis and R. arboreum had similar fruit mass. The seed fall density varied between 1.55 and 7.85 seeds m–2 and the maximum mortality of up to 32% of seedlings was observed during post-monsoon season from November to February. The potential disruption in the timing of seed fall, soil seed bank, and seed germination due to climatic irregularities has broader implications for forest ecosystems. Generally, the soil in treeline areas gets frozen during winter, resulting in seedlings facing severe water stress and a high rate of transpiration. The present study addresses the issue regarding the survival and proliferation of important treeline species in the western Himalayan region of India.

Soil seed bank (SSB) play an essential role in the restoration and regeneration of plant communities. Grazing is a common disturbance factor that exerts an important effect on the diversity and composition of the SSB community in forests. Here, we evaluated the structure and composition of SSB along a grazing disturbance gradient of two types of vegetation (broad-leaved forests and mixed coniferous broad-leaved forests) in southwest China. A comparison of the similarity of SSBs with the above-ground vegetation strata (tree, shrub and herb layers) was also analyzed. The experiment revealed the germination of 25 species that belonged to 14 families and 24 genera. The density of SSBs did not show significant differences along the grazing disturbance. The alpha diversity of SSBs was the highest at moderate grazing intensity in broad-leaved forests, and not significantly different along disturbance intensities in mixed coniferous broad-leaved forests. No significant changes were observed in the species composition of SSB along the grazing gradients. Nonmetric multidimensional scaling analyses revealed low similarities between SSBs and above-ground vegetation, with the lowest similarity occurring under medium grazing disturbance intensity. Overall, our research offers significant insight into the response of SSBs to grazing in different vegetation types. It serves as a guide for designing grazing management strategies tailored to natural forests.

BackgroundPhytogenic mounds are a type of microtopography formed under perennial plants canopies in water erosion areas. However, the function of phytogenic mounds in seed assemblages and their ecological consequences remain poorly understood in semiarid areas with water erosion. Thus, understanding the characteristics of seed banks on mounds is crucial for ecosystem conservation and management in water-eroded areas.MethodsWe compared the quantity and composition of soil seed banks on the upslope and downslope parts of mounds and intercanopy surfaces along four slope gradients. We also explored the relationships among the soil seed bank, aboveground vegetation, and environmental factors. Furthermore, the species similarity between the soil seed bank and aboveground vegetation was analyzed to clarify the important ecological consequences of phytogenic mounds for plant community construction in serious soil erosion area.ResultsFor slopes with α ≤ 46.6%, the intercanopy surfaces had greater soil seed bank species composition, density, and diversity than did the phytogenic mounds, and these characteristics showed no significant differences between the upslope and downslope parts of the mounds. As the slope increased, the soil seed bank density and species composition increased on the upslope part of the mound, and reached a maximum for slopes with α > 70%, while the downslope part of the mound negatively effected on seed aggregation. The sediment accumulation rate, soil moisture, particle size distribution, pH, organic matter carbon, and hardness were significantly correlated with the soil seed bank density and diversity in the study area. For slopes with 0 < α ≤ 26.8%, the species similarity coefficient between the soil seed bank and aboveground vegetation was the highest for the intercanopy surface. This species similarity on the upslope part of the mound showed an increasing trend with increasing slope gradient, while the downslope part of the mound had the opposite trend. For slopes with α > 70%, the upslope part of the mound did not only have more species in the soil seed bank but also had more species in aboveground vegetation than did the downslope part of the mound and intercanopy surface.ConclusionFor slopes with α ≤ 46.6%, phytogenic mounds had barely impact soil seed bank accumulation and conservation in semiarid and eroded areas. For slopes with α > 46.6%, the mounds (particularly on the upslope part of the mound) showed seed assemblage functions, which are coupled with improving edaphic conditions and decreasing microhabitat stress; thus, phytogenic mounds, or areas of microtopography, can be used to promote restoration success in semiarid eroded areas.

Background and aims: Soil seed bank plays a significant role in the natural recovery and the succession of forest. A large number of natural secondary forests are distributed in the Qining Mountains, China. However, it remains unclear how the soil seed banks develop and influence the recovery of secondary forests. Methods: We explored the aboveground vegetation and soil seed bank at 27 plots along forest developmental stages of pine and oak forests in the Qinling Mountains. Species composition and abundance of aboveground vegetation as well as seed bank composition and density were surveyed and their correlations with forest developmental stages were determined. Results: The results showed that the species richness of seed banks was the highest in middle-aged forests, as well as the aboveground vegetation. The seed density and abundance increased with forest developmental stages and varied among different forest types. The similarity between seed banks at different developmental stages of the same forest type was high, as well as aboveground vegetation. The seed bank and aboveground vegetation showed low similarity across the three developmental stages of both forest types, and the persistent soil seed bank did not reflect the changes in aboveground vegetation. Conclusion: Our findings demonstrate that developmental stages play an important role in the composition of seed banks and aboveground vegetation. Our results also highlight the persistent soil seed bank contributes less to the forest recovery. We can assume that the natural recovery of disturbed natural secondary forests is largely dependent on transient soil seed bank and seed dispersal. [ABSTRACT FROM AUTHOR]

Aiming to understand the responses of soil seed bank to different water levels, we investigated vegetation and soil seed bank along a water level gradient (frequently flooded area, unflooded area) on the floodplain wetland of Juzhang River. We used the structural equation model to explore the direct and indirect effects of water level on soil seed bank, and used non-metric multidimensional scaling (NMDS) to assess the role of soil seed bank for vegetation regeneration. The results showed that the density of transient and persistent seed banks at unflooded area was 36.9% and 7.8% higher than that of frequently flooded area, respectively. Shannon index and Pielou index of seed bank and vegetation were significantly affected by water level and sampling location. Water level significantly affected the similarity between seed bank and aboveground vegetation, and the similarity of persistent seed bank with aboveground vegetation was significantly higher than that with transient seed bank. Structural equation model showed that water level had a direct effect on seed bank density, and indirect effects on density and richness of seed bank via affecting soil pH and NH4+-N content. NMDS results showed that there was no significant difference in the composition of the persistent seed bank and vegetation community in autumn under different water levels, but water level significantly changed the community composition of transient seed bank. Transient seed bank was affected by the vegetation and soil property, while persistent seed bank was determined by aboveground vegetation and water level. Although soil seed bank had low regeneration potential for the vegetation communities in floodplain wetlands, soil seed bank could not be neglected during the restoration of propagule diversity after disturbance in wetlands. Persistent seed bank would be an importance source of diversity of propagules for floodplain wetlands restoration following disturbance. [ABSTRACT FROM AUTHOR]

Granivores, such as rodents and harvester ants, are common in dryland ecosystems. In intact dryland ecosystems, the effects of such granivores on soil seed banks, plant community structure, and ecosystem functioning are well established. However, the effects of granivores on dryland restoration have received much less attention. In this study, we evaluated the seasonality of seed removal by harvester ants, seed preference of harvester ants, and effects of granivore exclosure on the soil seed bank at four sites in southeastern Utah. We studied two species of harvester ants, Pogonomyrmex rugosus and P. occidentalis. The foraging behavior of Pogonomyrmex spp. was temperature‐dependent; they removed no seeds during winter months, and up to 80% of seeds during high activity in the summer. Despite seasonal differences in seed removal, Pogonomyrmex spp. did not show significant preferences for seed species. However, their seasonal foraging behavior translated into measurable differences in an experimental soil seed bank. Over the summer months, ants reduced the number of seeds in the seed bank by approximately 20%, but when ants were excluded during the winter, the number of seeds in the seed bank remained the same. This finding supports the timing of business‐as‐usual seeding practices of applying seeds in late fall. If seeds germinate in the first season after application, ant granivory is unlikely to pose a large barrier to establishment. However, if seeds remain dormant during the first year, as is common in many dryland species, seeds are vulnerable to ant granivory. [ABSTRACT FROM AUTHOR]

The soil seed bank plays a key role in vegetation resilience under environmental disturbances, and is especially important for the restoration of degraded vegetation. However, the responsive dynamics of the soil seed bank to animal grazing and its potential in the restoration of grazing degraded steppe grassland remain unclear. Here we examined the changes in plant species diversity and density in both the soil seed bank and the aboveground vegetation of a natural grassland along an experimental gradient of four grazing intensities (nil, light, moderate and heavy grazing) in an adaptive grazing management system that ensures grassland residual cover was always above a certain criteria. The grassland is a typical steppe dominated by Leymus chinensis, Stipa grandis, and Cleistogenes squarrosa in central Inner Mongolia, China. We found that (i) plant species richness and density of the seed bank in the top 10 cm soil layer increased with grazing intensity, though the density of the seed bank in the top 5 cm soil layer showed an decrease. (ii) Moderate and heavy grazing significantly decreased the density of perennial but increased annual and biennial plants in the top 5 cm soil layer, which dominate the changes in the top 10 cm soil layer. (iii) Plant species richness and density in the aboveground vegetation also increased with grazing intensity, so did the similarity between the species composition of the soil seed bank and aboveground vegetation in the top 10 cm. The increase in the richness and density of annual and biennial species dominated the responsive changes to grazing of the soil seed bank and aboveground vegetation in the studied grassland. Our results provide a reference basis for grazing management in the region from the perspective of the soil seed bank, and suggest that the adaptive grazing system with grassland residual height controlled above a criterion benefits to the soil seed bank thus the re-generation of vegetation.

To examine the effects of the recent Acmella radicans invasion on plant community and diversity in invaded habitats, the composition, density, species richness, diversity indices, and evenness index of the soil seed bank community of two different habitats (wasteland and cultivated land) in Yunnan Province, China, were analyzed through field sampling and greenhouse germination tests. A total of 28 species of plants belonging to 15 families and 28 genera, all annual herbs, were found in the soil seed bank. Seed densities and species number in the seed bank tended to be greater in April than in October; cultivated land also featured higher seed densities and species numbers compared to wasteland. With increased A. radicans cover, the seed bank population of A. radicans also significantly increased, but the seed bank populations of many other dominant species (e.g., Ageratum conyzoides and Gamochaeta pensylvanica) and native species (e.g., Laggera crispata and Poa annua) clearly declined. The germination of A. radicans seeds was concentrated during the period from the 4th to the 5th weeks. Vertically, the seed number of A. radicans was significantly different among the 0–5 cm, 5–10 cm and 10–20 cm layers that accounted for 80.7–90.6%, 9.4–16.1% and 0.0–3.2% of the total seed density in wasteland, respectively; and in cultivated land, A. radicans accounted for 56.8–64.9%, 26.7–31.8% and 8.1–13.5% of the total seed density, respectively. With reduced A. radicans cover, the species richness, Simpson index, Shannon–Wiener index, and Pielou indices of the weed community generally increased, and most diversity indices of weed communities in cultivated land were lower than in wasteland under the same cover of A. radicans. The results indicate that the invasion of A. radicans has negatively affected local weed community composition and reduced weed community diversity, and that these negative impacts in cultivated land may be enhanced by human disturbance. Our study was the first to elucidate the influence of A. radicans invasion on soil seed bank community characteristics in invaded habitats, providing a better understanding of its invasion and spread mechanisms in order to aid in developing a scientific basis for the prevention and control of this invader.

As a key component of the ecosystem, soil seed banks (SSBs) play a vital role in the evolution and renewal of plant communities. Although the pattern and mechanisms of influence of SSBs along the altitudinal gradient have been reported, most studies have focused on forest, grassland and alpine meadow ecosystems. The pattern and factors of SSBs across the altitudinal gradient in sedge peatlands remain largely unknown. Through vegetation surveys and seed germination experiments, we studied the changes in aboveground vegetation and SSBs in sedge peatlands at altitudes ranging from 300 m to 1300 m in the Changbai Mountains, China, and discussed the direct and indirect effects of climatic factors, soil properties and aboveground vegetation on SSBs. The results showed that the richness and density of the SSBs of sedge peatlands decreased with the altitude. Similarly, aboveground vegetation richness and density declined with altitude. A Spearman correlation analysis showed that SSB richness and density were mainly correlated with mean annual temperature, soil total phosphorus and ammonia nitrogen and the plant composition and richness of aboveground vegetation. A structural equation model analysis showed that climatic factors and aboveground vegetation directly affected seed bank richness, while soil properties indirectly affected it by directly affecting aboveground vegetation. Climatic factors, soil properties and aboveground vegetation directly affected SSB density, and soil properties indirectly affected it by directly affecting aboveground vegetation. This finding enhances our understanding of the altitude patterns of the SSBs in sedge peatlands and the response to future climate and environmental changes.

Summary: Information on seed persistence and seedling emergence from the soil seed bank is critical for understanding species coexistence and predicting community dynamics. However, quantifying seed persistence in the soil is challenging; thus, its association with other life‐history traits is poorly known on a broad scale.Using germination phenology for 349 species in a 42‐yr experiment, we quantified the persistence–emergence correlations and their associations with intrinsic regeneration traits using Bayesian phylogenetic multilevel models.We showed no trade‐off between seed persistence and seedling emergence. Physically dormant seeds were more persistent but exhibited lower emergence than nondormant seeds. Monocarpic species had both higher persistence and emergence than polycarpic species. Seed mass posed a marginal proxy for persistence, while emergence almost doubled from the smallest to the largest seeds.This study challenges the traditional assumption and is the first demonstration of noncorrelation between persistence and emergence, probably owing to the complexity of regenerative strategies. Species with short persistence and low emergence would be the most vulnerable for in situ conservation. Our analyses of this unique, long‐term dataset provide a strong incentive for further experimental studies and a rich data resource for future syntheses. See also the Commentary on this article by Meitzel, 241: 521–522. [ABSTRACT FROM AUTHOR]

Question: Patchiness of herbaceous species is a common feature of degraded alpine grasslands on the Qinghai–Tibet Plateau; however, the impact of this phenomenon on vegetation, soil seed bank (SSB), and soil carbon (C) and nitrogen (N) is largely unknown. We asked how different herbaceous patches affect above‐ground vegetation, the SSB and soil organic C (SOC) and total N (TN) contents in alpine meadows. Location: An alpine meadow on the Qinghai–Tibetan Plateau, China. Methods: We used field and greenhouse experiments to evaluate above‐ground vegetation parameters, the SSB composition, and SOC and TN contents of four commonly distributed herbaceous patches (Leymus secalinus, Kobresia humilis, Leontopodium nanum and Pedicularis kansuensis) and non‐patch vegetation (control). Results: There were significant differences in the species composition of above‐ground vegetation, with the plant species richness, Shannon–Wiener index, Simpson index, and Pielou evenness index reduced in the four patches compared to the control. In addition, patches had increased above‐ground biomass (AGB) and a lower below‐ground biomass to above‐ground biomass ratio (BGB:AGB); while the species diversity indices did not change considerably among the patches. The species composition of the SSB in the four patches differed from that in the control and the seed density increased markedly, but the species richness and diversity of the SSB remained unaltered. Moreover, the contents of SOC, total C, TN, microbial biomass C, and microbial biomass N in the four patches were markedly lower than in the control. Conclusions: These findings suggest that patchiness of herbaceous species can alter the flora composition of alpine meadows and reduce plant species diversity, as well as the SOC and TN contents, which will adversely impact grassland biodiversity conservation and soil C sequestration, and then may intensify the degradation of alpine meadows on the Qinghai–Tibet Plateau. [ABSTRACT FROM AUTHOR]

Increased atmospheric nitrogen (N) deposition affects biodiversity in terrestrial ecosystems. However, we do not know whether the effects of N on above‐ground plant β‐diversity are coupled with changes occurring in the soil seed bank. We conducted a long‐term N‐addition experiment in a typical steppe and found that above‐ground β‐diversity increased and then decreased with increasing N addition, whereas below‐ground β‐diversity decreased linearly. This suggests decoupled dynamics of plant communities and their soil seed bank under N enrichment. Species substitution determined above‐ and below‐ground β‐diversity change via an increasing role of deterministic processes with N addition. These effects were mostly driven by differential responses of the above‐ground vegetation and the soil seed bank β‐diversities to N‐induced changes in environmental heterogeneity, increased soil inorganic N concentrations and soil acidification. Our findings highlight the importance of considering above‐ and below‐ground processes simultaneously for effectively conserving grassland ecosystems under N enrichment. [ABSTRACT FROM AUTHOR]

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Long-term occupation of coal gangue dumping sites (CGDS) may destroy ecological environment of nearby area. However, how the CGDS affects the distribution pattern of soil seed banks and vegetation in the nearby area is not clear. In this study, we investigated soil seed bank and vegetation at different distances from the second CGDS of Yangchangwan in Ningdong mining area, Lingwu, Ningxia. The results showed that soil seed bank was mainly distributed in 0-10 cm layer and decreased with increasing soil depth. Species richness of soil seed bank and vegetation first increased and then tended to be stable with increasing distance to the CGDS. The influence range of CGDS on soil seed banks was 300-500 m and was 100-300 m on aboveground vegetation. The CGDS did not affect the vertical distribution pattern of soil seed bank, but significantly affected the horizontal distribution pattern of soil seed banks and aboveground vegetation. The key area of vegetation restoration around the CGDS was between 100 m and 300 m. [ABSTRACT FROM AUTHOR]

Background and aims – The cup plant (Silphium perfoliatum) is being grown in Germany as a promising new bioenergy crop with an increasing area under cultivation in the last years. Its alien status, its high productivity, and high reproductive potential could carry the risk of this species becoming invasive. The present study investigates the dispersal and persistence of cup plant seeds, to contribute to the assessment of its invasive potential. Material and methods – For this purpose, four experimental studies were conducted in Germany, Central Europe: wind dispersal distance was measured in a field experiment for wind speeds up to 7 m.s-1. The seeds were offered to rodents in different habitats near to a cup plant field. We observed seed persistence and germination over 4 weeks storing in water and over 4 years storing in different soil depths. Key results – Cup plant seeds are dispersed by wind only over a few meters. In the forest, rodents removed 100% of the offered seeds, in open habitats none. Independent of the duration of storage in water, germination rate of the cup plant seeds was constantly high. Most of the seeds already germinated in water in the first two weeks. Stored on the soil surface and at 10 cm soil depth, the seeds germinated already in the first two years. Stored at 30 cm depth, one third of the seeds retained their germination ability over four years. Conclusion – Wind serves as short-distance dispersal vector for cup plant seeds. Rodents remove the seeds, but it is unknown whether they disperse them or just eat them. Water could disperse the seeds, which retain their germination ability, over long distances. The cup plant could therefore spread and possibly become invasive in Central Europe, and therefore measures are suggested to prevent its dispersal and spontaneous settlement. [ABSTRACT FROM AUTHOR]

Pioneer trees require high‐light environments for successful seedling establishment. Consequently, seeds of these species often persist in the soil seed bank (SSB) for periods ranging from several weeks to decades. How they survive despite extensive pressure from seed predators and soil‐borne pathogens remains an intriguing question. This study aims to test the hypotheses that decades‐old seeds collected from the SSB in a lowland tropical forest remain viable by (i) escaping infection by fungi, which are major drivers of seed mortality in tropical soils, and/or (ii) maintaining high levels of seed dormancy and seed coat integrity when compared to inviable seeds. We collected seeds of Trema micrantha and Zanthoxylum ekmanii at Barro Colorado Island, Panama, from sites where adult trees previously occurred in the past 30 years. We used carbon dating to measure seed age and characterized seed coat integrity, seed dormancy and fungal communities. Viable seeds from the SSB ranged in age from 9 to 30 years for T. micrantha, and 5 to 33 years for Z. ekmanii. We found no evidence that decades‐old seeds maintain high levels of seed dormancy or seed coat integrity. Fungi were rarely detected in fresh seeds (no soil contact), but phylogenetically diverse fungi were detected often in seeds from the SSB. Although fungal infections were more commonly detected in inviable seeds than in viable seeds, a lack of differences in fungal diversity and community composition between viable and inviable seeds suggested that viable seeds are not simply excluding fungal species to survive long periods in the SSB. Synthesis. Our findings reveal the importance of a previously understudied aspect of seed survival, where the impact of seed–microbial interactions may be critical to understand long‐term persistence in the SSB. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

In many landscapes, successful re‐establisment of plant populations depends on the presence of diaspores, either near or directly beneath sites to be restored. The soil seed bank is, therefore, an important part of ecosystem resilience and a vital pillar for regeneration of genetic diversity in many plant populations. However, regeneration from the soil seed bank and the siubsequent restoration can only be considered successful when genetic diversity of restored populations is not eroded nor genetic differentiation inflated.We compared genetic variation within and among soil seed bank and aboveground populations of Origanum vulgare, to test whether genetically variable populations can be restored from the soil seed bank. We explored levels of genetic diversity within aboveground populations and the corresponding soil seed banks. Furthermore, we assessed the extent to which the soil seed bank differs genetically from the aboveground population.Levels of genetic diversity were to generally similar in aboveground populations and the corresponding soil seed banks. Only levels of inbreeding were slightly higher in the lower layer of the soil seed bank compared to the aboveground populations, probably because of selection processes acting against homozygotes accumulating in the seed bank. Furthermore, significant genetic differentiation between the aboveground population and the corresponding seed banks was completely absent. Across all sites, genetic differentiation between the soil seed bank was similar to that between aboveground populations, probably due to the absence of severe climate conditions, strong bottlenecks or disturbance events.Our conclusions support the possibility of successful re‐establishment of healthy, genetically variable plant populations after aboveground destruction or following soil re‐allocation from persistent seed banks. [ABSTRACT FROM AUTHOR]

Background. Many studies have focused on the dormancy-breaking response to heat treatment of freshly matured seeds and immediately after thermal shock. Aims. We evaluated whether the full effect of dry heat scarification in freshly matured seeds could be delayed over time and the possible influence of previous storage in the soil. Methods. Adenocarpus argyrophyllus was the model species selected to explore our hypotheses by analysing the: (a) influence of scarification treatments; (b) seedling emergence during 5 years after dry heat scarification of freshly matured seeds, and evaluating intrapopulation variation; (c) seedling emergence after dry heat scarification of seeds rescued from soil; and (d) ability to form persistent soil seed banks. Key results. Dry heat scarification of freshly matured seeds only resulted in 22.5% germination. However, exposure to pre-sowing thermal shock stimulated seedling emergence during the first few years post-planting, with high intrapopulation variation. In seeds recovered from soil, thermal shock before reseeding increased the seedling emergence rate. Conclusions and implications. Our results show that, to avoid incomplete interpretation, studies of thermal treatment on the breaking of physical seed dormancy should allow the seeds sufficient time to exhibit the complete effects of high temperature treatment, thereby preventing underestimation. [ABSTRACT FROM AUTHOR]

Premise: In 1879, Dr. William Beal buried 20 glass bottles filled with seeds and sand at a single site at Michigan State University. The goal of the experiment was to understand seed longevity in the soil, a topic of general importance in ecology, restoration, conservation, and agriculture, by periodically assaying germinability of these seeds over 100 years. The interval between germination assays has been extended and the experiment will now end after 221 years, in 2100. Methods: We dug up the 16th bottle in April 2021 and attempted to germinate the 141‐year‐old seeds it contained. We grew germinants to maturity and identified these to species by vegetative and reproductive phenotypes. For the first time in the history of this experiment, genomic DNA was sequenced to confirm species identities. Results: Twenty seeds germinated over the 244‐day assay. Eight germinated in the first 11 days. All 20 belonged to the Verbascum genus: Nineteen were V. blattaria according to phenotype and ITS2 genotype; and one had a hybrid V. blattaria × V. thapsus phenotype and ITS2 genotype. In total, 20/50 (40%) of the original Verbascum seeds in the bottle germinated in year 141. Conclusions: While most species in the Beal experiment lost all seed viability in the first 60 years, a high percentage of Verbascum seeds can still germinate after 141 years in the soil. Long‐term experiments such as this one are rare and invaluable for studying seed viability in natural soil conditions. [ABSTRACT FROM AUTHOR]

The quality and quantity of soil seed bank composition can play a key role in secondary succession restoration efforts such as those involved in this study, which concerned the restoration of damaged native sites in riparian environments in Victoria, Australia. The objective of this study of the restoration work was to determine the role played by naturally existing soil seed bank in the success of natural restoration in these restored and unmanaged riparian areas. In this regard, we sampled the soil seed bank, seed rain, seedlings in the field and vegetation cover from three sub catchments defined by restoration attempts which had been conducted (i) 9 years previous to sampling. In addition, (iv) in order to provide comparative data, adjacent sites (iv) chosen for future restoration and (v) with remnant vegetation, were also sampled. From samples, a total of 8858 seedlings were recorded from the seed bank and the vegetation survey showed 170 species, with exotic species being more numerous than native. The seed rain (a total of 1422 seeds) was dominated by exotic species at all sites. When comparing the vegetation distribution and the seed rain composition, it was clear that whilst the seed bank was more promising as a comparative recruitment source of native species, there were still too many sites dominated by exotic species to rely on this as a long-term restoration strategy. However, this study indicated that there were significant variations in restoration potential among the sites, suggesting that some careful prior site selection for investment of restoration efforts is an important issue. As a consequence, we have recommended that a detailed understanding of the soil seed bank and seed rain species composition prior to the restoration is essential, since a positive seed bank composition with a significant relative density of native species seeds, will provide an indication of native species’ resilience and their potential for recovery. We therefore believe that the findings of this study will provide valuable information to natural resource management agencies regarding the strategy for prioritisation of restoration sites, which will be more beneficial than randomly selecting sites for habitat restoration. In addition, with successful sector restoration, it is expected that the increasing usefulness of the seed bank will allow further restoration of adjacent areas with time.

Seed banks are crucial regenerative resources for aboveground vegetation. The pattern of their changes holds immense significance in understanding alterations in the belowground seed bank. This understanding is pivotal for uncovering both short-term and long-term shifts in plant communities. Additionally, it contributes to the restoration of grassland ecosystems. To better protect grassland biodiversity and provide a theoretical basis for the restoration of degraded grasslands, in this study, the germination characteristics of soil seed banks in free-grazed, enclosed and mown areas were compared, and the results were combined with those of previous studies for a comprehensive analysis. The density of soil seed bank and perennial forage soil seed bank were significantly affected by different grassland utilization and soil depths. Grazing and enclosure grassland utilization methods increased the content of the soil seed bank, and mowing reduced the content of the seed bank. The soil seed bank density of perennial grasses accounted for the highest proportion under grazing, followed by mowing, and its lowest proportion was observed in the enclosures. Grazing not only facilitated the germination of the perennial grass seed bank but also substantially augmented its content. Mowing inhibited the germination of the upper growth grasses seed bank, which was particularly significant in the 0-2 cm soil layer under grazing. The content of the upper growth grasses seed bank affected the total seed bank to a certain extent, mainly in the 5-10 cm layer. The general correlations among the perennial grasses, upper growth grasses and soil germination seed bank resulted in 84.58% information extraction, and this information has practical significance for grassland ecological restoration. [ABSTRACT FROM AUTHOR]

Soil seed bank is the growth and reproduction source of vegetation community, playing an important role in vegetation establishment, succession and renewal, biodiversity maintenance. This study has selected the nascent wetland in the Yellow River Delta (YRD) formed in 1996 as study area and investigated the diversity and key influencing factors of soil seed bank diversity. The study results show that: (1) The soil seed bank in the study area has a simple structure, containing relatively few species. A total of five plant species, which belong to four families and five genera, were found in this bank, with Phragmites australis and Suaeda salsa being the dominant plants. (2) All species are herbs without woody species. One herb is annual herb and the others are perennial herbs. (3) From the sea to the river, the changes rules of the overall density and diversity of the seed bank are not obvious. (4) The dispersal distance from salt and freshwater has a significant influence on the density of the soil seed bank but has no significant influence on the diversity. Meanwhile, the soil salt content has a significant negative influence on the diversity of seed banks. (5) Aboveground vegetation did not closely relationship with diversity of soil seed bank. All above results can provide basic data and scientific evidence for the conservation of vegetation communities in the nascent wetlands and vegetation restoration in the degraded wetlands in the YRD. [ABSTRACT FROM AUTHOR]

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Introduced plants can have long-lasting and irreversible effects on the communities and ecosystems they invade. A critical step towards understanding the legacy of plant introductions is the characterisation of changes in the invaded plant communities and how these changes are related to biogeochemical modifications. Here, we addressed this issue by comparing the impacts of two large invasive herbs, Gunnera tinctoria and Impatiens glandulifera, on the compositional, functional, and phylogenetic structure of the standing vegetation (above-ground communities) and the soil seed bank (below-ground communities). The introduction of both invasive species was associated with a significant decrease in above-ground species richness, with subsequent changes in the functional diversity and phylogenetic dispersion of the vegetation. Yet, these invaders differed in their long-term impacts and the reversibility of any modifications they caused. While G. tinctoria invasions resulted in phylogenetically clustered communities (both above and below-ground) that were clearly distinct from uninvaded ones, seed bank communities invaded by I. glandulifera were indistinguishable from uninvaded ones, despite major compositional changes above-ground. Further, we found alterations in nutrient cycling associated with G. tinctoria invasions that could facilitate its local persistence and exacerbate any negative effects on native diversity. Our findings suggest a high susceptibility of pre-invasion above-ground communities to colonisation by distantly related herbs. However, the seed banks showed a degree of resilience against both invaders, with no major differences in species richness. Ultimately, differences in the impacts of these large invasive herbs suggest that dominance in the vegetation and a large stature are poor predictors of long-term plant community changes, including regeneration potential from seed, which are associated with plant introductions. [ABSTRACT FROM AUTHOR]

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Key messageBet-hedging is a complex evolutionary strategy involving morphological, eco-physiological, (epi)genetic and population dynamics aspects. We review these aspects in flowering plants and propose further research needed for this topic. Bet-hedging is an evolutionary strategy that reduces the temporal variance in fitness at the expense of a lowered arithmetic mean fitness. It has evolved in organisms subjected to variable cues from the external environment, be they abiotic or biotic stresses such as irregular rainfall or predation. In flowering plants, bet-hedging is exhibited by hundreds of species and is mainly exerted by reproductive organs, in particular seeds but also embryos and fruits. The main example of bet-hedging in angiosperms is diaspore heteromorphism in which the same individual produces different seed/fruit morphs in terms of morphology, dormancy, eco-physiology and/or tolerance to biotic and abiotic stresses in order to 'hedge its bets' in unpredictable environments. The objective of this review is to provide a comprehensive overview of the ecological, genetic, epigenetic and physiological aspects involved in shaping bet-hedging strategies, and how these can affect population dynamics. We identify several open research questions about bet-hedging strategies in plants: 1) understanding ecological trade-offs among different traits; 2) producing more comprehensive phylogenetic analyses to understand the diffusion and evolutionary implications of this strategy; 3) clarifying epigenetic mechanisms related to bet-hedging and plant responses to environmental cues; and 4) applying multi-omics approaches to study bet-hedging at different levels of detail. Clarifying those aspects of bet-hedging will deepen our understanding of this fascinating evolutionary strategy.

As a repository of genetic information of above-ground vegetation, the soil seed bank plays an important role in the natural succession and renewal of vegetation and the construction of ecological restoration. In this paper, three typical plant communities in the rocky desertification area of Gongcheng Yao Autonomous County were selected for the study, and soil seed bank structure and diversity in different communities and their response to soil nutrient characteristics were analyzed. The results were as follows：(1) A total of 3 648 seedlings belonging to 55 species in 51 genera and 33 families were detected, which included 20 species of 1, 2-year-old herbs, 21 species of perennial herbs, 5 species of vines, 3 species of shrubs and 6 species of trees; the average density of soil seed bank of different plant communities in karstic desertification areas of Gongcheng was Prunus salicina economic forest (22 493 grain·m-2) > Cyclobalanopsis glauca secondary forest (1 033 grain·m-2) > Phyllostachys sulphurea shrub (793 grain·m-2). (2) As for the plant life type of the soil seed bank, the soil seed bank life type of Prunus salicina economic forest was mainly annual malignant weeds, the plant life type of the soil seed banks in the Cyclobalanopsis glauca secondary forest and Phyllostachys sulphurea shrub was dominated by perennial herbs, while woody plants account for a relatively small proportion; the species diversity and similarity of the soil seed banks of different vegetation types were generally low, while the species composition of the soil seed banks also had low similarity with the aboveground communities. (3) The soil elements in the study area had higher nitrogen content and lower phosphorus content, and phosphorus was a limiting factor for plant growth in Phyllostachys sulphurea shrub and Quercus glauca secondary forest. In conclusion, the plant community in the stone desertification area of Gongcheng has some native germplasm resources, but overall shows a low species diversity, and it is urgent to introduce native tree species artificially to accelerate the positive vegetation succession on the basis of natural sequestration, and pay attention to nutrient management, especially the regulation of phosphorus elements. The results provide a theoretical reference for karst stone desertification management and vegetation restoration in Gongcheng.

Close-to-nature restoration of mining areas is becoming widely recognized for its promotion of ecosystem resilience and risk mitigation of biodiversity losses. Soil seed banks can serve as a direct source of natural restoration, as well as a buffer against environmental changes in vulnerable ecosystem. However, in arid mining area, it remains unclear how the anthropogenic disturbances affect the seed banks and what its potential for vegetation restoration. We conducted a field study to investigate the variation of aboveground plant communities and seed banks along the disturbance gradient in an opencast mining area in arid desert of northwestern China. Furthermore, we detected the influence path of disturbance on seed bank density and richness at different layers. The seed bank had considerable density, with persistent seed accounting for 46%. The density had no significant differences along the none-to-moderate disturbance gradient but decreased significantly at the severe level. Meanwhile, the richness had significant differences among all disturbance levels with the highest value at mild level. There were low similarities between soil seed bank and aboveground vegetation, and their species composition was distinctly different. The anthropogenic disturbances reduced soil seed bank directly. Besides, it indirectly decreased the density of persistent seed bank at shallow layer via the negative impact on silt content. In contrast, disturbance indirectly reduced transient seed density and richness mainly via the positive effect on aboveground vegetation. Briefly, mild-to-moderate disturbance had limited negative effects on the soil seed bank and its restoration potential in the arid mining region. Our study highlights the soil seed banks as supplementary indicator to reflect ecological degradation and the significance for ecosystem recovery. The results could be useful in protection and management projects for the restoration of arid mining areas.

Topsoil resources are important resources for ecological restoration in mining areas, although the topsoil stripped in practical projects can not be used for ecological restoration immediately. The changes that occur in topsoil after a certain period of storage in arid areas are not clear, so we have no insight on how to make the best use topsoil for ecological restoration after storage in the mining areas. Therefore, this study investigated the effects of topsoil accumulation on seed density and topsoil nutrient content in seed banks, which could provide a technical basis for vegetation reconstruction of coal mine damaged land in desert areas and theoretical support for ecological restoration practices. In this study, two storage methods of round table piles (hereafter referred to as YT) and cube ton bags (hereafter referred to as DD) were used to preserve uniformly mixed topsoil samples, and the loss of the soil seed bank and nutrient depletion under different topsoil storage methods were analyzed. In the two storage modes, the soil seed density loss on the surface of the pile was the largest, and the loss rate was 79.30%–83.65%. At a given sampling location, soil seed density increased significantly with soil depth (P<0.05). Compared with the change in seed density, soil nutrient loss was less pronounced, and the loss rate was between 8.92% and 16.62%. The seed density loss of the topsoil was the highest in both stacking modes. With the increase in the soil layer, soil seed density was significantly increased (P<0.05). At the same time, there was no significant difference in seed loss between the two storage modes. In the process of preservation, shrub seeds were the most seriously lost in the pile. The nutrient preservation effect of the ton bag storage mode (DD) was better than that of the round table storage mode (YT), and the soil nutrient loss of the top layer of the pile was the greatest, while the soil nutrient losses of other soil layers were lower. [ABSTRACT FROM AUTHOR]

The Asteraceae with up to 30,000 species occurs on all continents except Antarctica and in all major vegetation zones on earth. Our primary aim was to consider cypselae dormancy-break and germination of Asteraceae in relation to ecology, vegetation zones and evolution. Cypselae are desiccation-tolerant and in various tribes, genera, species and life forms of Asteraceae are either non-dormant (ND) or have non-deep physiological dormancy (PD) at maturity. All six types of non-deep PD are found among the Asteraceae, and dormancy is broken by cold or warm stratification or by afterripening. Soil cypselae banks may be formed but mostly are short-lived. Much within-species variation in dormancy-break and germination has been found. Using data compiled for 1192 species in 373 genera and 35 tribes of Asteraceae, we considered ND and PD in relation to life form, vegetation zone and tribe. Senecioneae and Astereae had the best representation across the vegetation zones on earth. In evergreen and semi-evergreen rainforests, more species have ND than PD, but in all other vegetation zones, except alpine/high-latitude tundra (where ND and PD are equal), more species have PD than ND. Tribes in the basal and central grades and those in the Heliantheae Alliance have both ND and PD. The high diversity and lability of non-deep PD may have enhanced the rate of species diversification by promoting the survival of new species and/or species in new habitats that became available following globally disruptive events since the origin of the Asteraceae in the Late Cretaceous. [ABSTRACT FROM AUTHOR]

As a repository of genetic information of above-ground vegetation, the soil seed bank plays an important role in the natural succession and renewal of vegetation and the construction of ecological restoration. In this paper, three typical plant communities in the rocky desertification area of Gongcheng Yao Autonomous County were selected for the study, and soil seed bank structure and diversity in different communities and their response to soil nutrient characteristics were analyzed. The results were as follows:(1)A total of 3 648 seedlings belonging to 55 species in 51 genera and 33 families were detected, which included 20 species of 1, 2-year-old herbs, 21 species of perennial herbs, 5 species of vines, 3 species of shrubs and 6 species of trees; the average density of soil seed bank of different plant communities in karstic desertification areas of Gongcheng was Prunus salicina economic forest(22 493 grain·m-2)> Cyclobalanopsis glauca secondary forest(1 033 grain·m-2)> Phyllostachys sulphurea shrub(793 grain·m-2).(2)As for the plant life type of the soil seed bank, the soil seed bank life type of Prunus salicina economic forest was mainly annual malignant weeds, the plant life type of the soil seed banks in the Cyclobalanopsis glauca secondary forest and Phyllostachys sulphurea shrub was dominated by perennial herbs, while woody plants account for a relatively small proportion; the species diversity and similarity of the soil seed banks of different vegetation types were generally low, while the species composition of the soil seed banks also had low similarity with the aboveground communities.(3)The soil elements in the study area had higher nitrogen content and lower phosphorus content, and phosphorus was a limiting factor for plant growth in Phyllostachys sulphurea shrub and Quercus glauca secondary forest. In conclusion, the plant community in the stone desertification area of Gongcheng has some native germplasm resources, but overall shows a low species diversity, and it is urgent to introduce native tree species artificially to accelerate the positive vegetation succession on the basis of natural sequestration, and pay attention to nutrient management, especially the regulation of phosphorus elements. The results provide a theoretical reference for karst stone desertification management and vegetation restoration in Gongcheng. [ABSTRACT FROM AUTHOR]

Some research indicates that soil seed banks can promote species coexistence through storage effects. However, the seed bank mechanism that maintains plant assembly and its role in degraded grassland restoration are still not clear. We collected seed bank samples from early, mid and late secondary successional stages of an abandoned subalpine meadow on the Tibetan Plateau, and samples from each stage were exposed to full (i.e., natural), mid, and low light treatments in the field to represent light availability at the bottom/understory (soil surface) of a plant community in the early, mid and late stages of succession, respectively. Species richness, seed density, species composition, and community weighted mean values (CWMs) of seed mass of the species whose seeds germinated in soil samples were evaluated. In response to the light treatments, species richness increased significantly with increased light only for the late successional stage, seed density increased significantly with increased light only in the early and mid successional stages, and seed mass decreased significantly with increased light only in the mid and late successional stages. Species composition differed significantly among the light treatments only in the late successional stage. For the successional series, species richness and seed mass of the species that germinated increased significantly with succession only under mid and full light treatments. Seed density decreased significantly with succession in each light treatment. Species composition differed significantly between the early‐ and late stage and between the mid and late stage in each light treatment. Both the abiotic (light) and biotic (seed mass) factors influence seed bank recruitment to the plant community. Regeneration of small‐seeded species in the seed bank was inhibited under low light in the late successional stage. The balance of stochastic and deterministic processes along a successional gradient was determined by regeneration from the seed bank depending on light intensity change. Differences in seed response to light intensity change largely determined plant community assembly. Our findings should help in the development of effective conservation and restoration strategies. [ABSTRACT FROM AUTHOR]

Long-term active restoration is often employed to restore degraded grasslands. The establishment of a viable soil seed bank is the key to successful restoration, as it enhances the resilience of vegetation. However, little is known of how the soil seed bank affects vegetation resilience following long-term active restoration of degraded grasslands. We determined seed abundance and species composition of the soil seed bank and soil properties and vegetation resilience of intact, degraded, and long-term (>10 years) actively restored grasslands on the Tibetan plateau (3900–4200 m a.s.l.). The plant-soil-seed bank quality index and structural equation modelling (SEM) were used to assess the effect of the soil seed bank on vegetation resilience. After long-term (>10 years) active restoration of degraded grasslands by sowing seeds of native plant species, the densities of transient and persistent seeds increased by 5%, but seed richness (number of species) decreased by 25% when compared with degraded grasslands. This occurred largely as a result of an increase in grass but decrease in forb seeds. Persistent seeds of grasses play an important role in the productivity of restored grasslands, while the density of persistent seeds serves as an indicator of the resilience of vegetation. A combination of the plant community and soil properties determined seed density. Here, we show for the first time that long-term active restoration enhances vegetation resilience of grasslands by altering the soil seed bank. A high seed density of sown Gramineae and a low seed density of forbs in the soil seed bank is a key to the successful active restoration of degraded grasslands. [ABSTRACT FROM AUTHOR]

In order to increase biodiversity in cultivated areas, the implementation of agri-environmental programs is proposed, including interventions and eco-schemes. Flower strips are one such proposal. In order to achieve satisfactory results, the appropriate selection of plants is crucial. In flower strips, the number and diversification of overwintering plant species are important. Our observations suggest that the species diversity observed in the second year of the strip's presence in western Poland composed of mostly annual 14 plant species did not overlap in the next year. The flower strip was established on soils in a very good rye complex. The average monthly air temperature in both seasons was similar. In the winter months after the establishment of the flower strip, the lowest temperature at the ground level and the lowest air temperature were recorded in December (−5.4 °C and −13.7 °C, respectively). Hydrological conditions were not favorable, including a very dry March. Wild species originally from the soil seed bank were dominant. The selection of the appropriate species composition of mixtures intended for flower strips should take into account not only the preferences of beneficial insects but also environmental conditions. The possibilities of the selected plant species are important. A large variety of spontaneously emerging species (considered weeds) can also successfully colonize existing gaps in the flower strips, providing an increase in biodiversity. From the beginning of June to the end of July, the share of flowering plants from the seed bank ranged from 42.59% to 88.19%, while among originally intended plant species, it was only 11.81–57.41%. In May and at the beginning of June, two intended species that were intensively flowering, Trifolium incarnatum L. (over 70.5%) and Phacelia tanacetifolia Benth. (26.47%), were definitely dominant. In later observations, it was noted that, unfortunately, the sown plants had a low level of flowering compared to the wild plants found in the flower strip. It is very important that flower strips include species that also bloom in July and August, and wildflower plants can highlight the attractiveness of the flower strip to beneficial insects and are a valuable addition. This paper evaluates the suitability of a commercially available seed mixture in terms of the floristic attractiveness and overwintering potential of annual plants. [ABSTRACT FROM AUTHOR]

In Nigeria, Chromolaena odorata (L.) R. M. King and H. Rob and Tithonia rotundifolia (Mill.) S. F. Blake, are exotic invasive weeds, but a gradual decrease in the population of C. odorata with the rapid invasion of T. rotundifolia is now observed. Therefore, this study investigated the adaptive features of each weed in competition, with a further determination of seedling recruitment from the soil seed bank of plots invaded by T. rotundifolia. Field sampling was carried out in 10 plots: T. rotundifolia invaded plots and low or uninvaded plots in co-existing with other plants using 10 m x 10 m quadrats. The readily germinable seed species composition and the Sorensen index of similarity between the seed bank and their above ground vegetation were determined. Competition Series Experiment was also conducted for the two plants. Mariscus alternifolius (227) and Oldenlandia corymbosa (358) were the most abundant species in the seed bank while T. rotundifolia recruited 25 individuals. Low similarity index existed between the seed bank and the standing vegetation of the invaded and uninvaded plots. T. rotundifolia had improved growth in heteroculture with C. odorata over when in monoculture. However, a reduction in growth of C. odorata occurred when in competitive association with T. rotundifolia compared to when in monoculture. T. rotundifolia had competitive advantage over C. odorata.