土壤种子库的研究现状与进展综述

土壤种子库是指存在于土壤表层掉落物和土壤中全部活性种子的总和。土壤种子库是现在植物种群生态学研究中不可缺少的一部分。土壤种子库时期是植物种群生活史的一个重要阶段,有人称之为潜种群阶段,是种群的定居、生存、繁衍和扩散的基础。土壤种子库理论作为群落生态学和恢复生态学的基础理论,是退化生态系统重建的重要组成部分,已成为植物生态学研究的热点问题。随着其发生发展,土壤种子库研究方法更加科学准确,研究内容得到了不间断的更新和补充,研究领域涉及了植物学、遗传学、生态学、杂草科学和农学等各科学。至此,土壤种子库已经形成了相对完善的理论框架,主要包括:1.土壤种子库的研究的沿革;2.土壤种子库的特征3.土壤种子库的动态变化4.土壤种子库的分类问题5.土壤种子库的研究方法6.对植物生态学的贡献。     

Advances in Understanding Seed Dormancy at the Whole-seed Level:An Ecological, Biogeographical and Phylogenetic Perspective

Following a brief account of the early foundations of seed germination ecology sensu lato, some historical and recent developments pertaining to the ecology, biogeography and phylogeny of seed dormancy are discussed.     

海草种子特性与海草床修复

海草床面积的急剧减少已引起人们对海草床生态修复的重视, 种子在海草床修复中具有较大的应用潜力。该文系统归纳了近年来有关海草种子的研究概况及其应用进展: 从种子生物学和生态学角度对海草种子的形态结构、发育、散布、休眠和萌发进行了归纳比较; 提出了在研究天然海草种子库的同时, 有必要建立人工海草种子库的观点, 并指出建立和完善人工海草种子库需基于种子生物学和生态学研究, 以指导种子的采集和保存; 对海草种子的播种方式和利用种子修复海草床的途径进行了阐述, 并指出了目前研究和应用中存在的一系列问题。最后对海草种子的研究和应用前景进行了展望, 提出海草种子生态学将成为今后的研究热点, 在应用方面, 仍然需要以提高种子萌发率和成苗率为研究重点, 并指出如果利用由种子获得的人工幼苗进行海草床修复, 需首先解决幼苗成活率低的难题。     

Seed germination traits can contribute better to plant community ecology

Analyses of functional traits have become fundamental tools for understanding patterns and processes in plant community ecology. In this context, regenerative seed traits play an important, yet overlooked, role because they largely determine the ability of plants to disperse and re‐establish. A survey of recent publications in community ecology suggests that seed germination traits in particular are neglected at the expense of other relevant but overused traits based only on seed morphology. As a response to this bias, we discuss the functional significance of seed germination traits in comparison with morphological and biophysical seed traits, and advocate their use in vegetation science. We also demonstrate how research in community assembly, climate change and restoration ecology can benefit from the inclusion of germination traits, encompassing functions that cannot be explained solely by adult plant traits. Seed germination experiments conducted in the laboratory or field to quantify these traits provide ecologically meaningful and relatively easy‐to‐obtain information about the functional properties of plant communities. We argue that bridging the gap between seed physiologists and community ecologists will improve the prediction of plant assemblages, and propose further perspectives for including seed traits into the research agenda of functional community ecologists.     

土壤种子库研究综述

土壤种子库是指存在于土壤表面和土壤中全部存活种子的总和。土壤种子库研究是植物生态学研究的一个重要领域。研究土壤种子库是对生物多样性研究的一个重要补充 ,有助于对植被更新和植被演替动态的了解 ,对于植被重建与恢复具有指导意义 ,有利于指导我们的生产实践。本文从土壤种子库研究的取样方法、研究内容及进展等方面进行一个较系统的总结 ,为将来的研究提供一些有益的途径。     

Post‐dispersal seed recovery by animals: is it a plant‐ or an animal‐driven process?

The ability of animals to find and consume hoarded seeds (i.e. seed recovery) is a key stage within the seed dispersal process. However, the ecology of seed recovery is still poorly understood. Here, we analyze the factors controlling seed recovery by scatter‐hoarding rodents in an oak‐dominated temperate forest. We examined the relative importance of intrinsic seed traits (i.e. plant‐driven) and extrinsic seed factors (i.e. animal‐driven) on the probability of seed recovery. We found that seed recovery is mainly driven by extrinsic seed factors, mostly related to animal behavior (pilfering frequency, microsite preference, predation risk, burial depth and cache size). Important intrinsic traits such as seed size, seed quality and seed‐drop timing were, on average, of lower significance in the probability of seed recovery (2.8‐times less important than extrinsic factors); only seed quality was an important intrinsic trait. On the other hand, larger and nutritionally more valuable seeds showed a removal–recovery tradeoff as they enhance seed removal and hoarding (increasing dispersal quality) but also favour seed recovery (increasing predation). We find that other mechanisms beyond seed traits (e.g. masting) are needed to decrease seed recovery and, thus, increase seed survival. We conclude that, as seed recovery is mostly driven by animal behavioural factors, it substantially differs from other previous stages of the seed dispersal process that are more dependent on seed traits. We argue that seed recovery needs further attention to advance our understanding of the ecology of seed dispersal and the role of secondary dispersers as a selective force for seeds.     

Reproductive ecology of Aloe plicatilis,a fynbos tree aloe endemic to the Cape Winelands,South Africa

While the pollination ecology of many Aloe species is well-documented, knowledge on aloe seed ecology, and hence aloe reproductive ecology in its entirety is limited. The aim of this study was to investigate the reproductive ecology of Aloe plicatilis, a Cape fynbos tree aloe endemic to the Cape Winelands, South Africa. Results from a pollinator exclusion experiment conducted at an A. plicatilis population on Paarl mountain suggests pollination primarily by insects, although bird visitation significantly increased seed set/fruit indicating possible co-pollination with insects. The species' long-tubed flowers and production of concentrated nectar, with observations of malachite sunbirds as the most common avian visitors to A. plicatilis flowers indicate the importance of long-billed specialist avian nectarivores as floral visitors. Analysis of the relationship between plant size and inflorescence production for five populations combined revealed a significant, positive linear relationship between plant size and the logarithm of the number of inflorescences/plant. Natural fruit and seed set determined for three populations (1325, 27,930 and 251,616 seeds/population) suggests low reproductive output compared to several other Aloe species. The smallest (31 individuals) and least dense (75 plants/ha) A. plicatilis population produced the lowest seed set/plant (128 seeds) and per population (1325 seeds), suggesting an Allee effect. Evaluation of seed dispersal potential showed that potential dispersal distances were approximately three times the canopy height; however, the occurrence of A. plicatilis on mountains isolated from more continuous mountain ranges on which the species also occurs suggests the possibility of long-distance dispersal by strong, gusty, summer winds. Soil seed bank samples collected from 13 populations yielded close to zero seedling emergence, indicating the absence of persistent seed banks. A. plicatilis seeds stored under ambient laboratory conditions for 3, 18 and 24 months were germinated in an environmental control chamber and a laboratory. High percentage germination was recorded for 18- and 24-month-seed (86 and 80%, respectively), while germination of 3-month-old seeds was three times lower, suggesting the need for after-ripening. Germination of fresh and one-year-old seed under ambient nursery conditions at the Karoo Desert National Botanical Garden in Worcester yielded emergence percentages of 67 and 44%, respectively, and were therefore less successful than germination under more controlled conditions. This is the first known study to investigate the reproductive ecology of a tree aloe species and that of a Cape fynbos aloe. The study highlights the importance of further studies on aloe seed ecology, particularly for rare and threatened species.     

The Ecology and Evolution of Fruit Odor: Implications for Primate Seed Dispersal

Primates are now known to possess a keen sense of smell that serves them in various contexts, including feeding. Many primate species are frugivorous and provide essential seed dispersal services to a variety of plants. Studies of pollination ecology, and recently seed dispersal ecology, indicate that animal mutualist behavior exerts selection pressures that drive changes in flower and fruit traits. As a result, the use of olfaction in in primate feeding ecology may have affected the evolution of fruit odor in species that rely on primate seed dispersal. However, this hypothesis is seldom tested. Here, we summarize the available information on how primates may have affected the evolution of fruit odor. We ask what the chemistry of primate fruit odor may look like, what information fruit odor may convey, whether there are geographical differences in fruit odor, and what other factors may affect the odor of fruits consumed by primates. We identify many gaps in the available data and offer research questions, hypotheses, and predictions for future studies. Finally, to facilitate standardization in the field, we discuss methodological issues in the process of odor sampling and analysis.     

种子微生物生态学研究进展

植物种子微生物生态学是研究与种子相联合的微生物的组成﹑功能﹑演替、它们之间关系及其与宿主之间相互关系的科学。种子中蕴含着丰富的微生物资源,它们对种子以及植物的健康具有重要的影响。不同种类植物种子联合的微生物群落由于受到种子本身及外界环境因素的影响而有所差异。论述了种子微生物生态学的概念、主要研究方法、种子微生物生态系统中的微生物种类、相关影响因素,以及种子微生物生态学研究的发展方向。种子微生物生态学的研究对生产实践有重要意义,同时也将丰富种子生物学的内容,对种子科学的发展起到促进作用。     

甘草野生种群果实与种子形态特征的地理变异研究

目的：研究甘草荚果和种子形态特征地理变异规律并分析其形成的生态学机制。方法：采用样方调查的方法测定全国4省区8个旗县甘草野生种群的地上植株形态特征,采用双重筛选逐步回归分析方法探讨甘草荚果和种子形态特征的地理变异规律及其形成的生态学机制。结果：（1）不同甘草种群的荚果数、荚果腺毛长度、种室数目、每荚种子粒数和结实率5项指标的差异达到了极显著水平（P〈0．01）;荚果长度、荚果厚度、荚果腺毛密度和种子长度4项指标的差异达到了显著水平（P〈0．05）。（2）荚果厚度、种室数目等5项形态特征与经度呈显著相关,只有荚果腺毛长度1项指标与纬度显著相关。结论：甘草野生种群荚果与种子形态特征存在显著的地理变异,其变异趋势以经向变异为主,光照因子差异是导致地理变异的主要原因,其次为温度因子和水分因子,其相关关系可用多元回归模型解释。     

Only seed size matters for germination in different populations of the dimorphic Tragopogon pratensis subsp. pratensis (Asteraceae)

Many studies have focused on the ecology of seed dimorphism, the production of two seed types by a single plant. Morphology and seed size are usually correlated, but how morphology affects germination percentage and seedling growth is poorly understood. Here we explicitly separate these effects for nine populations of the dimorphic species Tragopogon pratensis subsp. pratensis. Larger seeds yielded higher germination percentages, yet seed morphology had no additional direct effect on germination. Neither seed size nor seed morphology affected seedling growth. Neither germination nor seedling growth varied among populations, but seed head varied significantly. Results show that germination is mainly controlled by seed size rather than by seed morphology. This study is one of the few to distinguish explicitly between seed size and seed morphology effects on ecological characteristics and suggests that seed dimorphism may exert its ecological effects predominantly through its correlated size.     

Ecological niche and phylogeny explain distribution of seed mass in the central European flora

Seed size is a crucial life‐history trait determining the amount of reserves that are available to establishing seedlings. The most frequently observed patterns in seed size distribution are a higher frequency of large‐seeded species in shaded habitats and a positive correlation of seed size with plant size. We analysed to what extent realised niche dimensions, as expressed by Ellenberg indicator values and plant functional traits such as plant height and life form, explained seed mass variation in the central European flora. By including information on phylogenetic relatedness of the species, not only contemporary ecology but also the evolutionary history of plant species could be taken into account. Seed mass evolution was slow and was best explained by selection‐inertia models with multiple adaptive peaks as a function of either habitat or life form. The highest seed mass optima were observed in the deciduous forest and saltwater and seashore habitats, and in phanerophytes in case of models with optima as a function of life form. The analyses showed that Ellenberg values were more important than habitat and life form in explaining seed mass distribution in the central European flora. The often observed relation between shade and large seeds was also evident in our study, but we found an equally important relation between large seeds and drought and a positive relation between seed mass and salinity. Our results indicate that not only plant size and competition for light but a complex set of factors influence the ecology of seed size, and that a more precise delineation of species’ niches improves the understanding of seed size evolution.     

Pollination ecology and pollination system of Impatiens reptans (Balsaminaceae) endemic to China

BACKGROUND AND AIMS: China is one of the centres of geographical distribution of Impatiens L. Studies of the pollination ecology of this genus in China have, until now, been unreported. Impatiens reptans, a species endemic to China, was studied. The aims were to examine the pollination ecology and pollination system of this species, to compare its pollination ecology with other Impatiens species growing in Sumatra and Japan, and to discuss possible reasons for its limited distribution. METHODS: The pollination ecology of I. reptans was studied by carrying out continuous observations within three naturally growing populations. Its pollination system was studied using different pollination methods, marking and counting pollen grains, assessing pollen viability and observing pollinator behaviour. KEY RESULTS: The flowering phase of the protandrous I. reptans lasted for 89 d. The life span of an individual flower was 3.6 d. Primary pollinators were honey-bees and bumble-bees. Secondary pollinators were diurnal hawk moths and butterflies. Bombus briviceps and Bombus sp. were nectar gatherers. The mean nectar sugar concentration was 29.5 %, and the mean value of sucrose/glucose + fructose was 0.82. The proportion of seed set ranged from 0.857 to 0.873. Distances that seeds were ejected ranged from 0.58 to 1.17 m. Percentage seed germination under controlled conditions was 23.1. Pollen viability was highest on the day of anthesis and thereafter decreased. Ratios of pollen : ovules ranged from 958.8 to 970.6. CONCLUSIONS: Impatiens reptans reproduces by means of cross-pollination. Its dependence on a specialized habitat, a narrow environmental niche, a low percentage of seed germination, and habitat loss could be reasons for its limited distribution and endemism.     

Multiple causes of seedling rarity in scrub plum, Prunus geniculata (Rosaceae), an endangered shrub of the Florida scrub

Conservation of an imperiled plant often requires an understanding of its reproductive ecology. Scrub plum (Prunus geniculata) is an endangered Florida shrub endemic to pyrogenic xeric uplands. Although plants are long-lived and may flower profusely, particularly after burning, fruit yield is sparse and seedlings are rare. We investigated potential causes of seedling rarity in scrub plum by studying its floral sex and breeding systems, fruit development, and germination ecology. We also developed a flow chart based on two time-since-fire scenarios to illustrate the cumulative impact of these factors on seedling recruitment. Breeding system experiments suggested partial gametophytic self-incompatibility in this functionally andromonoecious species, with inbreeding depression in self-compatible individuals. Predispersal seed predation, the major constraint on seedling recruitment, was lower in the first postburn season. In two field experiments, seed germination was <11% irrespective of treatment. These results indicate that seedling recruitment in scrub plum may be limited by multiple factors, including sexual reproductive failure, high predispersal seed predation, and low seed germination. The chance of a bisexual flower producing a seedling ranges from 5 in 1000 to 5 in 100000, depending on the time since fire. Restoration of scrub plum's historical fire regime may mitigate some of these factors.     

The ecology of germination and reproduction of less frequent and vanishing species of the Czechoslovak flora IV.Melilotus altissima Thuill

The ecology of seed germination was examined in air-conditioned boxes in the laboratory, and the sprouting of seeds was investigated in an experimental plot at Pr?honice. The seeds show a marked dormancy caused by the impermeability of testa to water (seed hardcoatness). 72–100% of hard seeds were found in 16 seed samples. Seed hardcoatness is an important protective strategy of the species against the frost killing of seedlings and, on the other hand, for the longevity of seeds (Table 3) and for the possibility of endochoric spreading. It is also important to establish seed supply in the soil. The seed sprout from the first decade of April till the beginning of May. The soft seed sprout as early as in autumn, and the seedlings freeze out (Table 4).     

Possible predation of cysts--a gap in the knowledge of dinoflagellate ecology?

A theoretical model of dinoflagellate ecology is presented.The model incorporates currently neglected aspects of potentialimportance in the field of plankton research, such as lossesto the cyst seed bank due to predation or microbial degradation.     

Tree seed traits’ response to monsoon climate and altitude in Indian subcontinent with particular reference to the Himalayas

Seed traits are related to several ecological attributes of a plant species, including its distribution. While the storage physiology of desiccation‐sensitive seeds has drawn considerable attention, their ecology has remained sidelined, particularly how the strong seasonality of precipitation in monsoonal climate affects their temporal and spatial distribution. We compiled data on seed mass, seed desiccation behavior, seed shedding, and germination periodicity in relation to monsoon and altitude for 198 native tree species of Indian Himalayas and adjoining plains to find out (1) the adaptive significance of seed mass and seed desiccation behavior in relation to monsoon and (2) the pattern of change in seed mass in relation to altitude, habitat moisture, and succession. The tree species fall into three categories with respect to seed shedding and germination periodicities: (1) species in which both seed shedding and germination are synchronized with monsoon, referred to as monsoon‐synchronized (MS, 46 species); (2) species in which seed germination is synchronized with monsoon, but seeds are shed several months before monsoon, referred to as partially monsoon‐synchronized (PMS, 112 species); and (3) species in which both shedding and germination occur outside of monsoon months, referred to as monsoon‐desynchronized (MD, 39 species). The seed mass of MS species (1,718 mg/seed) was greater than that of PMS (627 mg/seed) and MD (1,144 mg/seed). Of the 40 species with desiccation‐sensitive seeds, 45% belong to the MS category, almost similar (approx. 47%) to woody plants with desiccation‐sensitive seeds in evergreen rain forests. Seed mass differed significantly as per seed desiccation behavior and successional stage. No relationship of seed mass was found with altitude alone and on the basis of seed desiccation behavior. However, seed mass trend along the altitude differed among monsoon synchronization strategies. Based on our findings, we conclude that in the predicted climate change (warming and uncertain precipitation pattern) scenario, a delay or prolonged break‐spell of monsoon may adversely affect the regeneration ecology of desiccation‐sensitive seed‐bearing species dominant over large forest areas of monsoonal climate.     

Frugivores and seed dispersal: mechanisms and consequences for biodiversity of a key ecological interaction

The 5th Symposium on Frugivores and Seed Dispersal, held in Montpellier (France), 13-18 June 2010, brought together more than 220 researchers exemplifying a wide diversity of approaches to the study of frugivory and dispersal of seeds. Following Ted Fleming and Alejandro Estrada's initiative in 1985, this event was a celebration of the 25th anniversary of the first meeting in Veracruz, Mexico. Frugivory and seed dispersal are active research areas that have diversified in multiple directions since 1985 to include evolution (e.g. phylogenetic diversity and dispersal adaptations), physiology (e.g. sensory cues and digestion), landscape ecology (movement patterns), molecular ecology (e.g. gene flow, genetic diversity and structure), community ecology (e.g. mutualistic interaction networks) and conservation biology (effects of hunting, fragmentation, invasion and extinction), among others. This meeting provided an opportunity to assess conceptual and methodological progress, to present ever more sophisticated insights into frugivory in animals and dispersal patterns in plants, and to report the advances made in examining the mechanisms and consequences of seed dispersal for plants and frugivores.     

萌发前处理和种子大小对瓜拉那(Paullinia cupana var.sorbilis)种子萌发的影响

为了增加对瓜拉那(Paullinia cupana var.sorbilis)种子萌发特性的了解,寻求提高瓜拉那种子萌发的最佳条件,本研究用控制实验,研究了瓜拉那种子去/不去假种皮、不同种子大小和酸处理下的萌发行为.结果表明,去假种皮且酸处理的大种子发芽率最高,为100%;不去假种皮且无酸处理的小种子基本不萌发;去假种皮种子发芽率显著高于未去假种皮种子;种子大小对萌发率有显著影响,大种子比小种子趋于有更高的萌发率;酸处理能进一步提高去假种皮种子萌发率.     

我国植物种群生态研究的成就与展望

种群生态学以种群作为研究对象,无论在理论上还是在方法上都是生态学中发展最快,最为活跃的一个领域,也是生态学研究中的一个极其重要的层次,因为它是物种存在和进化的基本单位,是生物群落和生态系统的基本组成。一、植物种群生态学研究的历史Graunt于1662年进行了人类种群的生命