黄土高原自然植被演替过程中的植物特征与土壤元素动态

在 3～ 14 9年的时间尺度上 ,对黄土高原植被次生演替过程中植物特征和土壤养分元素动态进行了研究。结果表明 :1)随着演替时间尺度的延伸 ,土壤全C、全N含量呈增加趋势 ,而土壤全K、全Na和土壤pH值呈下降趋势 ,土壤全P变化趋势不明显 ;此外 ,表层 (0～ 10cm)土壤CaO含量在演替系列上呈下降趋势 ,深层 (2 0～ 30cm ,4 0～5 0cm)则呈增加趋势。演替过程对几种土壤化学元素含量影响的程度随着土壤深度的增加而减弱。 2 )植物群落物种丰富度在演替的中间阶段最高。 3)在演替的早期阶段 ,植物群落优势种往往具有稳定的土壤种子库、CR_生活对策和S_繁殖对策 ,在贫瘠的土壤上具有较强的竞争能力 ,且具有较强的水平扩展能力和克隆繁殖能力 ,C_生活对策、在土壤全N含量较高的生境中具有较强竞争能力的多年生植物 ,在演替中后期占据群落的优势地位。此外 ,在所涉及的植物特征中 ,多年生生活史 ,C_、CR_、SC_、SR_、S_生活对策 ,以及R_、W_、Bs_、VBs_和V_繁殖对策等特征在非优势物种中出现的频率较高。 4 )C_、SC_生活对策 ,克隆能力 ,多年生生活史 ,水平扩展能力 ,种子的动物传播方式 ,秋季开花 ,荚果、坚果等特征出现的比例在一定程度上与土壤全C、全N和全K含量正相关 ;而S_、SR_、R_、CR_生活对策 ,一、二年生     

南亚热带森林不同演替阶段植物与土壤中N、P的化学计量特征

选择南亚热带森林演替过程3个阶段(初期、中期和后期)的典型森林生态系统为研究对象, 在测定植物与土壤中全N、全P含量的基础上, 阐明了森林演替过程中植物与土壤的N、P化学计量特征。结果显示: 1)土壤中全N含量随演替进行而增加, 马尾松(Pinus massoniana)林(初期)、混交林(中期)和季风林(后期) 0-10 cm土层中全N含量分别为0.440、0.843和1.023 g·kg^-1; 混交林0-10 cm土层中全P的含量最为丰富, 为0.337 g·kg^-1, 马尾松林和季风林土壤全P含量分别为0.190和0.283 g·kg^-1。2)植物叶片中全N、全P的含量随演替呈减少的趋势, 但根系中全N、全P的含量都以马尾松林为最多, 混交林和季风林含量彼此相当。3)各土层中N:P随演替的进行呈现明显增加趋势, 马尾松林、混交林和季风林0-10 cm土层中N:P分别为2.3、2.5和3.6; 植物各器官中N:P随演替的进行也呈增加趋势, 且叶片和根系中的N:P相近, 马尾松林、混交林和季风林叶片中N:P分别为22.7、25.3和29.6。基于上述结果, 探讨了南亚热带森林生态系统植物与土壤中N:P特征、森林演替过程中植物与土壤中N:P变化规律以及P对南亚热带森林生态系统的限制作用。结果表明, P已经成为南亚热带森林生态系统生物生长和重要生态过程的限制因子。     

茂兰喀斯特森林不同演替阶段植物叶片功能性状与土壤因子的关系

植物如何改变功能性状来适应环境一直是生态学的研究征点。为探究茂兰喀斯特森林不同演替阶段植物叶片的适应策略，该文以茂兰自然保护区5个不同演替阶段(草本、灌木、灌乔、乔木和顶极群落阶段)优势种为研究对象，测定不同演替阶段的优势植物叶片功能性状与土壤理化性质。结果表明：(1)随着植被正向演替的进行，土壤全氮(STN)含量、土壤有机质(SOM)含量、土壤含水量(SWC)逐渐增加，土壤全磷(STP)含量和土壤全钾(STK)含量先增加后减少，土壤pH值整体呈减小的趋势。(2)随着植被演替的进行，叶面积(LA)、叶干物质含量(LDMC)、叶厚度(LT)和叶片碳含量(LCC)逐渐上升，比叶面积(SLA)与叶片钾含量(LKC)则与之相反，叶片氮含量(LNC)呈先升后降的趋势，叶片磷含量(LPC)呈先降后升的趋势。(3)冗余分析表明，演替初期植物主要分布在土壤pH值高而STK、STP、SWC、SOM、STN相对低的环境中，群落内植物叶片采取高SLA、LNC、LPC,低LA、LDMC、LT、LWC的性状组合，演替晚期植物主要分布在土壤水分和养分含量较高的环境，LDMC、LT、LA、LWC与演替初期相比呈上升...     

Community succession and photosynthetic physiological characteristics of pasture plants in a sub-alpine meadow in Gannan,China

 为了解甘南亚高山草甸围封地恢复演替动态, 探究围封恢复进程中植物光合生理特征的变化规律及其影响因子, 对围封试验地内5个典型群落样地进行样方调查, 测定了各群落优势种及3个共有种的光合参数和叶性状参数, 并测定了群落表层土壤(0–20 cm)的水分含量及全氮含量。结果显示: 该围封地内形成一个以草本植物→半灌木→灌木的演替序列, 群落表层土壤含水量及全氮含量随着演替的进行逐渐增加; 在演替的时间尺度上, 各演替阶段优势种光合生理特征间存在明显差异, 随着演替的进行, 群落优势种的净光合速率(A_area)、光合水分利用效率(WUE)、相对叶绿素含量(SPAD)呈降低趋势, 其叶片氮含量(N_mass)、光合氮利用效率(PNUE)、比叶面积(SLA)随演替变化没有严格一致的规律, 而更多地表现为不同植物功能型之间的差异; 从演替前期到后期, 同种植物的A_area、SPAD值逐渐降低, 非豆科植物披碱草(Elymus dahuricus)、老鹳草(Geranium wilfordii)的PNUE、WUE随演替进行呈降低趋势, 其N_mass、SLA随演替进行却呈增加趋势, 然而豆科植物紫苜蓿(Medicago sativa)由于具有固氮能力, 受养分限制不明显, 这些光合生理特征值没有随演替发生明显的变化。这些结果表明, 在恢复演替过程中, 该围封地由一个物质获得能力强的群落向物质保持能力强的群落过渡, 土壤水分含量及全氮含量是推动这种过渡发生的主要因子。掌握围封地群落演替过程中的光合生理动态对于亚高寒退化草甸恢复具有一定的理论指导意义。     

荒漠草原区弃耕地植被演替过程中植物群落生物量及土壤养分变化

采用空间变化代替时间变化的方法,以荒漠草原区不同年限(1、4、9、12和20年)弃耕地为对象,研究弃耕演替过程中植物群落生物量与土壤养分的变化特征.结果表明： 随弃耕年限的增加,弃耕地植物群落地上生物量呈先减少后增加的趋势,0～60 cm土层的土壤全氮、全磷和有机碳含量及碳密度均呈先增大后减小再增大的趋势,4年和20年弃耕地的土壤全氮、全磷含量达到峰值.弃耕演替过程中土壤全氮和有机碳含量对植物群落生物量的影响大于土壤容重和土壤全磷.     

海岛森林不同演替阶段土壤和植物的碳、氮、磷化学计量特征

该研究采用空间代替时间的方法,对福建省东部海域的平潭岛林区不同演替阶段群落(灌草丛、针叶林、针阔混交林、常绿阔叶林)的土壤和植物的C、N、P含量进行测定,分析不同演替阶段土壤和植物的C、N、P及生态化学计量特征的变化规律,并探讨植物与土壤养分之间的相互关系。结果表明:(1)由于土壤C、N、P的来源不同,导致土壤有机碳(SOC)和全氮(STN)含量随着演替进行逐渐增加,土壤全磷(STP)含量呈先下降后上升的趋势;土壤C∶N随演替进行呈增加趋势,土壤C∶P和N∶P呈先升高后下降的趋势。(2)植物叶片碳(LC)含量随着演替进行呈先升高后下降的趋势,叶片氮(LN)和磷(LP)含量呈先下降后升高的趋势,反映了各演替阶段植物采取不同的生态适应性;植物叶片C∶N和C∶P随演替进行呈先升高后下降的趋势,植物叶片N∶P呈逐渐增加的趋势。(3)相关分析表明,土壤SOC与STN呈显著正相关关系,表明土壤C、N元素有较强的耦合关系;植物LN与LP呈显著正相关关系,共同反映植物的光合作用;植物叶片LP与土壤STP呈显著正相关关系,且植物叶片N∶P在各演替阶段均大于16,说明平潭岛植物生长主要受到土壤P限制。     

云南普洱季风常绿阔叶林演替系列植物和土壤C、N、P化学计量特征

通过测定中国西南季风常绿阔叶林不同演替阶段(演替15a,演替30a及原始林)群落中植物叶片与土壤中C、N、P含量,探索了季风常绿阔叶林不同演替阶段群落C、N、P化学计量特征及其与物种丰富度及多度的相关性。结果表明:土壤及植物中全N、全P含量及土壤中C含量均为演替30a群落中最低,而植物中C含量在不同演替阶段群落间无显著性差异。在不同演替阶段共有种中,40%的物种N含量原始林中最高,40%的物种P含量演替15a群落中最高,而80%的物种C含量无显著性差异。土壤中C:N比在不同演替阶段间无显著变化,而N:P及C:P比则随演替呈减小趋势。植物中C:N及C:P比均为演替30a群落最高,而N:P比则随演替呈增加趋势。不同演替阶段共有种的C:N比中,40%的物种原始林中最低,40%的物种无差异,而C:P与N:P比中则均有60%物种无显著性差异,但70%物种在演替15a群落中N:P小于14,演替30a群落中50%物种N:P在14—16,原始林中则有80%物种N:P大于16。群落物种丰富度及个体多度均与C:N、N:P、C:P无显著的相关性,但植物中的N、P与土壤的N、P分别具有显著的线性正相关,说明土壤中N、P供应量影响植物体中的N、P含量。     

内蒙古典型草原不同恢复演替阶段植物养分化学计量学

对内蒙古典型草原不同恢复演替阶段群落土壤养分动态及空间格局、植物养分及其化学计量比时空动态、植物与土壤养分相关性等进行了分析, 以揭示放牧干扰对植物的养分及其化学计量比影响。结果表明: 土壤各养分含量表现为恢复群落略高于严重退化群落, 土壤全氮(STN)/土壤全磷(STP)恢复群落高于严重退化群落, 土壤有机质(SOC)/STN恢复群落低于严重退化群落; 大多数植物叶片C含量在恢复群落最高, 严重退化群落最低, 与恢复演替时间呈正相关, 而植物的全氮(TN)和全磷(TP)含量则是严重退化群落最高, 恢复群落最低, 与退化程度呈正相关, 且TP含量的变幅明显高于TN含量; 植物叶的N:P和C:N表现为严重退化群落最低, 与退化程度呈负相关; 严重退化群落植物相对于P而言, 总体上表现为缺N; 而恢复群落相对于N而言, 更为缺P, 或同时缺N和P; 群落优势种化学计量学特征对群落演替方向有一定的指示作用。     

高寒矮嵩草群落退化演替系列氮、磷生态化学计量学特征

运用历史资料与实地调查相结合的方法,以多元数量统计为手段确定采样地点,以空间尺度代替时间尺度,确定演替系列,以生态化学计量学为基础探讨了高寒矮嵩草草甸退化演替系列氮(N)磷(P)含量及化学计量学特征,发现:1)高寒矮嵩草草甸土壤全量N、P含量随退化演替程度的加深而呈倒"V"字形变化趋势,速效N、P含量随退化程度的加深呈降低趋势,但土壤草甸全量及速效N/P化学计量学特征则呈现降低趋势;2)地上植物N/P化学计量学特征在整个退化演替过程没有明显的差异。说明高寒矮嵩草群落退化改变了土壤中全量及速效N、P的积累和分解速率,打破了土壤系统养分平衡模式,但并没有明显改变植物地上部分整体的N/P化学计量学特征,因此在退化演替过程中植物N/P比为草地退化诊断的惰性指标;土壤N/P化学计量学特征变化同草地退化演替过程具有较好的同步性,其对草地退化演替的敏感性较高,有可能成为未来草地退化诊断的生态指示指标。     

滇西北高原纳帕海湿地植物多样性与土壤肥力的关系

采用植物群落研究法与原状土就地取样技术,研究了滇西北高原典型退化湿地纳帕海植物多样性、土壤养分、酶活性格局特征及其相互关系.随着湿地原生沼泽向沼泽化草甸、草甸的演替,湿地植物群落盖度增加、物种组成增多,群落优势种优势度减小,伴生种数量增加,植物多样性呈增加趋势;湿地土壤有机质、全氮含量不断减少,过氧化氢酶、蛋白酶、蔗糖酶活性增加,脲酶活性降低.植物α多样性指数(辛普森、香浓-维纳指数)与湿地土壤有机质、全氮含量呈负相关,与土壤过氧化氢酶、蛋白酶、蔗糖酶活性呈正相关,与脲酶活性呈负相关;土壤有机质、全氮含量与过氧化氢酶、蛋白酶、蔗糖酶活性呈一致负相关,与脲酶活性则成正相关.湿地景观在一定程度上反映了人为生产活动干扰的类型与强度,其植物多样性、土壤养分和酶活性特征及其相互关系是湿地生态系统演替过程中时空间体现,研究结果揭示了人为干扰下湿地退化的生态学过程及机理,可为我国高原湿地生物多样性保护,退化湿地生态恢复与湿地资源可持续利用提供一定的理论依据.     

How do species dominating in succession differ from others?

Abstract. Data on succession were collected from 15 seres starting on bare ground in man-made habitats (i.e. sites disturbed by various mining activities, bulldozed sites, ruderal urban sites, the exposed bottom of a destroyed water reservoir, and abandoned fields), all in the western part of the Czech Republic, Central Europe. The period for which the data on succession were available ranged from 12 to 60 yr. 56 species reaching dominance in some period of succession were selected (the criterion being: at least 25 % cover in at least one year in any sere); they were compared for biological and ecological traits with other species participating in the seres (167 species with at least 1 % cover in at least one year in any sere), and with the Central European flora as a whole. Significant differences between the species dominating in succession and others were found for the following traits: life form, life strategy, pollination mode, and ability of lateral spread. Dominant species differed from the regional flora in distribution of life strategies, pollination mode and immigration status. The results suggest that an ‘ideal successional dominant’ is a tall, wind-pollinated plant, often a geophyte capable of intensive lateral spread, requiring high nutrient supply and sufficient site moisture. The set of traits contributing to achieving dominance by a species in human-made habitats includes both features occurring independently of phylogenies (life strategy, pollination mode, plant height, moisture demands) and those which dominant species probably share due to their common ancestors (nutrient demands, capability of extensive lateral spread).     

Spontaneous Establishment of Woody Plants in Central European Derelict Sites and their Potential for Reclamation

The performance of woody plants was analyzed in 15 successional seres starting at bare ground in central European manmade habitats. The total cover of woody species after 10 years of succession was significantly related neither to initial soil moisture nor to nitrogen (expressed using Ellenberg indicator values). But the comparison of seres indicates that establishment of woody plants was easier under moderate environmental conditions and retarded in extreme habitats (dry, nutrient-poor, or acid). The arrival of the first woody plants was delayed in dry sites. No significant differences were found between primary and secondary seres, either with respect to the total cover of woody plants reached after 10 years of succession or considering the time of their arrival. In total, 24 woody species (10 shrubs and 14 trees) appeared in the series investigated. Their successional performance (in terms of the number of seres in which the species occurred and maximum cover reached in any sere) was not related to species traits (life strategy, type of mycorrhizae, mode of dispersal, diaspore weight), except for the regeneration strategy, species with seasonal regeneration by seeds were capable of creating higher cover. Betula pendula (European birch) was the most successful species in spontaneous succession, especially on moist sites. Practical suggestions for the management of particular habitats (sites disturbed by mining, sites reclaimed after acid rain deforestation, urban sites, abandoned fields) are provided regarding the establishment of woody plants.     

Relationship between light availability and species richness during fen grassland succession

The complex relation between standing crop and species richness in herbaceous plant communities is still one of the most intensively discussed topics in vegetation ecology. In this study, we focus on the extent to which light availability is able to explain this relationship in fen grasslands. We analyse changes of light availability (measured as relative irradiance, RI), standing crop and species richness during fen grassland succession. Our study include communities representing differences in drainage intensity and nutrient status (‘land use intensification sere’) and successional stages developing after abandonment (‘abandonment seres’). Both in the land use intensification sere and in the abandonment seres, we recorded an increase in standing crop reaching highest values of approx. 800 g m^‐2. RI, species richness and number of small‐growing species declined in the successional seres. RI was highest in stands of low‐productive communities, where light compensation points (5% RI) were already attained at soil surface and light saturation points (30% RI) at soil surface or at 15 cm height. Horizontal heterogeneity of RI at soil surface and at 30 cm height decreased in the abandonment seres, but not at 30 cm height in the land use intensification sere. Furthermore, we detected a signiñcant negative relation between standing crop and RI. Species richness declined with increasing standing crop and thus consequently also with decreasing RI. This result points out that light competition might be of importance for this pattern. The number of small‐growing species decreased exponentially with an increase in standing crop (and decrease in RI). It can be assumed that low light availability negatively affects small‐growing species at standing crop values higher than 400–500 g m². As the maintenance of small‐growing species and the improvement of habitat conditions for their establishment are important aims of nature conservation in fen grasslands, management strategies should be orientated at maintaining standing crops that are not higher than these values.     

Changes in life history trait composition during undisturbed old-field succession

This paper describes the patterns of vegetation change by spontaneous succession on former agricultural land. In 1968, initiated by Heinz Ellenberg, an experimental study site was set up on an arable field in the new botanical garden of Göttingen University (Germany). The undisturbed successions on four plots of a long sere (since 1968/69) and on four additional plots of a shorter sere (since 1982) were evaluated. The seres were classified into stages by cluster analysis, which yield to four subsequent stages for the long sere and to three subsequent stages for the short sere. The early succession is characterized by a high proportion of species invasion, whereas with developing time species extinction increased. On all study plots undisturbed succession directed to the development of pioneer forests. Altogether 247 vascular plant species were recorded. The total species richness shows a fluctuating course during the successional seres, with significantly increased numbers shortly after succession has started and a decline in the pioneer-forest stage, when stands age and close down. The primary aim was to compare the characteristics (particular traits) of species occurring at different stages of succession. The majority of the traits concerned exhibited some clear trends in the course of succession. Exclusive reproduction by seeds decreased and the ability for additional vegetative reproduction increased. Anemochorous dispersal significantly decreased, whereas the importance of dispersal by animals, especially endochorous, dominates in the pioneer-forest stage. The mean seed weight significantly increased. During early succession, plant species staying green over winter dominated, but are of none relevance in the pioneer-forest stage, where summergreen plant species dominate. The change in strategy type features a significant increase of competitive species. The mean indicator value for light in the herb layer decreased significantly in the pioneer-forest stage.     

Consequences of abandonment for a regional fen flora and mechanisms of successional change

Abstract. Until the 1960s, species-rich vegetation on minero-trophic peaty soüs (fen sites) were characteristic of the alluvial plains in Schleswig-Holstein (Northwest Germany). Today, many of these habitats undergo successional changes due to abandonment. Vegetation development after abandonment can be characterized as a sequence of different successional stages and described in terms of a successional model. Successional stage I includes grazed, mown and recently abandoned sites without dominants. Stages II and III are characterized by the dominance of highly competitive herbaceous species whüe stage IV consists of woody vegetation. Ca. 3000 phytosociological relevés were assigned to the respective successional stages. Mean cover values were calculated for 250 species of the regional fen flora and assigned to successional categories according to their changes in cover in the successional series. According to our results 141 species decrease during succession, while 100 species were restricted to early successional stages and 85 species increased. Abandonment of all fen sites in Schleswig-Holstein will probably lead to the regional loss of 23 species of the fen flora. To identify mechanisms underlying successional change, the successional categories were correlated with life history traits and ecological requirements of the species. Results indicate that both light competition and limitation of sexual reproduction of small-seeded species might play a major role in the decrease and extinction of species during succession. Finally, conservation strategies for endangered species in a cultural landscape are discussed.     

Woody species colonisation in relation to habitat productivity

A study was conducted to analyse the effect of habitat productivity on woody species colonisation. Three soil types were distinguished: a relatively poor sandy soil type (1), a somewhat richer sandy type (2) and a relatively rich sandy loamy type (3). Chronosequences were established on these three soil types of 38 (type 1), 20 (type 2) and 54 years (type 3) after abandonment. In total 117 vegetation relevées were used to analyse life form change and species responses during old field succession via regression models. On the rich soil type the colonisation rate of woody species was slower than on the poor soil type. This can be explained by higher abundances of perennial species during the first 20 years after abandonment on the rich soil type in contrast to the poor soil type. Perennial species may delay the woody species colonisation. First they close the bare ground which inhibits germination and next they compete with woody seedlings for light, water and nutrients. The effect of habitat productivity on woody species colonisation can only be determined appropriately by taking life history traits into account. Early successional 'pioneer' woody species dispersed by wind have less difficulties colonising old fields than late successional 'forest' species; they colonise old fields prior to the development of a dense perennial sward. Forest species depend on animals to be dispersed which are attracted by vegetation structure. In ± 30 years on the poor soil type and in ± 45 years on the rich soil type woody species become dominant relative to other life forms. Forest species like Quercus robur L. invaded relatively early (<5 years) in contrast to other studies which probably coincides with the distance to seed sources (forest edges).     

Dynamics of vesicular-arbuscular mycorrhizae during old field succession

Summary The species composition of vesicular-arbuscular mycorrhizal (VAM) fungal communities changed during secondary succession of abandoned fields based on a field to forest chronosequence. Twenty-five VAM fungal species were identified. Seven species were clearly early successional and five species were clearly late successional. The total number of VAM fungal species did not increase with successional time, but diversity as measured by the Shannon-Wiener index tended to increase, primarily because the community became more even as a single species, Glomus aggregatum, became less dominant in the older sites. Diversity of the VAM fungal community was positively correlated with soil C and N. The density of VAM fungi, as measured by infectivity and total spore count, first increased with time since abandonment and then decreased in the late successional forest sites. Within 12 abandoned fields, VAM fungal density increased with increasing soil pH, H₂O soluble soil C, and root biomass, but was inversely related to extractable soil P and percent cover of non-host plant species. The lower abundance of VAM fungi in the forest sites compared with the field sites agrees with the findings of other workers and corresponds with a shift in the dominant vegetation from herbaceous VAM hosts to woody ectomycorrhizal hosts.     

Can the Study of Natural Vegetation Succession Assist in the Control of Soil Erosion on Abandoned Croplands on the Loess Plateau,China?

In the Loess Plateau, China, arable cultivation of slope lands is common and associated with serious soil erosion. Planting trees or grass may control erosion, but planted species may consume more soil water and can threaten long‐term ecosystem sustainability. Natural vegetation succession is an alternative ecological solution to restore degraded land, but there is a time cost, given that the establishment of natural vegetation, adequate to prevent soil erosion, is a longer process than planting. The aims of this study were to identify the environmental factors controlling the type of vegetation established on abandoned cropland and to identify candidate species that might be sown soon after abandonment to accelerate vegetation succession and establishment of natural vegetation to prevent soil erosion. A field survey of thirty‐three 2 × 2–m plots was carried out in July 2003, recording age since abandonment, vegetation cover, and frequency of species together with major environmental and soil variables. Data were analyzed using correspondence analysis, classification tree analysis, and species response curves. Four vegetation types were identified and the data analysis confirmed the importance of time since abandonment, total P, and soil water in controlling the type of vegetation established. Among the dominant species in the three late‐successional vegetation types, the most appropriate candidates for accelerating and directing vegetation succession were King Ranch bluestem (Bothriochloa ischaemum) and Lespedeza davurica (Leguminosae). These species possess combinations of the following characteristics: tolerance of low water and nutrient availability, fibrous root system and strong lateral vegetative spread, and a persistent seed bank.     

Allocation strategies and seed traits are hardly affected by nitrogen supply in 18 species differing in successional status

Species performance depends on ecological strategies, revealed by suites of traits, conferring different relative ecological advantages in different environments. Although current knowledge on plant strategies along successional gradients is derived from studies conducted in situ, actually quantifying these strategies requires disentangling the effects of environmental factors from intrinsic differences between species.Here we tested whether allocation strategies and seed traits differ among successional stages and nitrogen levels. To this aim, we assessed biomass and nitrogen allocations and seed traits variations for 18 species, differing in life history and belonging to three stages of a Mediterranean old-field succession. These species were grown as monocultures in an experimental garden under limiting and non-limiting nitrogen supply.Early successional species allocated allometrically more nitrogen and proportionally more biomass to reproduction, and set more seeds than later successional species. Seed mass increased with successional status and was negatively related to seed number. Early successional species thus produced more but less-provisioned seeds, suggesting better colonization abilities. These patterns were not the sole consequence of the replacement of annuals by perennials along the successional gradient, since comparable trends were also observed within each life history. Allocation patterns were generally not altered by nitrogen supply and the higher nitrogen content in vegetative organs of plants grown under high nitrogen supply was not retranslocated from leaves to seeds during seed development.We therefore conclude that differences in plant ecological strategies in species characteristics from contrasting successional stages appear to be intrinsic properties of the studied species, and independent from environmental conditions.