结缕草属（Zoysia Willd．）植物物候期的差异分析

于2005年至2006年在南京市对结缕草属（Zoysia Willd．）5种1变种共109份种源的物候期进行了系统观测分析。结果表明,不同种源间各植物物候期的时间存在不同程度的差异,其中进入盛花期、枯黄期、返青期、结实期、初花期和孕穗初期的时间分别相差58、56、38、35、33和29d;不同种源的青绿期为215～277d。孕穗初期的早晚与初花期、盛花期、结实期和枯黄期的早晚及青绿期的长短呈显著正相关,返青期早晚与青绿期的长短呈极显著负相关,而枯黄期的早晚与青绿期的长短则呈极显著正相关,说明返青期越早青绿期越长,枯黄期越早青绿期越短。另外,结缕草属植物的返青期、孕穗初期、初花期、盛花期及枯黄期均随原分布地纬度的增加显著提前。     

不同山丹居群在保定的生长特性分析

对25个居群的山丹在保定地区的物候期、生长期特性进行了调查分析。结果表明,不同山丹居群的物候期存在明显差异。萌芽期和开花期最早的为辽宁居群,最晚的为易县和邯郸居群,萌芽期相差37～39 d,开花期相差将近3个月。25个居群的不同生长发育阶段(花蕾发育期、花期天数、生长周期)所需的时间长短不一。不同居群山丹生长曲线基本一致,均为慢-快-慢的生长趋势。相关分析表明纬度与山丹的萌芽期、现蕾期、始花期、末花期、果熟期、枯萎期之间均呈极显著负相关。山丹的自然物候期也存在明显早、晚差异,这为百合育种提供了良好的资源。     

莎车巴旦姆物候期对气象条件的响应及花期预测模型

利用莎车县农业气象试验站2008—2013年巴旦姆物候期和同期气象观测资料,分析了巴旦姆物候期的变化特征以及气温、日照时数对物候期的影响.结果表明：巴旦姆花期之前的物候期始日之间均呈正相关,与花期之后的物候期始日的相关性大多较小,花芽膨大早迟与休眠期、生长期天数分别呈极显著的正相关和负相关.以果实成熟期为界,气温对之前、之后物候期间隔日数的影响分别为负相关和正相关,日照时数与物候期间隔日数大多为正相关.果实成熟 叶变色始期间隔日数对平均最高气温以及花序出现 开花末期、叶变色始期 落叶末期间隔日数对日照时数存在明显的响应.当巴旦姆休眠期符合日平均气温-3.0～-7.5 ℃的天数满30 d后,经过17～28 d将进入花芽萌动期.花芽萌动期、开花始期、叶变色始期和落叶末期的始日分别与首个候平均气温≥4 ℃且候平均最高气温≥12 ℃、春季侯平均气温≥14 ℃且侯平均最高气温≥22 ℃、秋季首个侯平均气温≤10 ℃且侯平均最高气温≤18 ℃和冬季首个侯平均气温≤1.9 ℃的候序一一对应.利用偏最小二乘法回归分析,建立巴旦姆盛花期始日预测模型,经过检验模型效果较好.     

北京植物园引进植物物候变化随纬度变化的环境解释

探讨了北京植物园主要引进树种的物候与原产地物候差异在纬度梯度上的变化机制。通过多元回归的方法在环境梯度上建立了最佳能量模型, 降水模型和海拔模型, 以此来解释引进的24 种植物物候随纬度梯度在叶期(叶芽开放, 展叶期, 盛叶期)和花期(始花期, 盛花期, 花末期)上的变化规律。结果表明: (1)物候因子变化与纬度变化呈现极显著相关(p < 0.001), 纬度梯度变化越大, 物候变化也越加剧烈。(2)海拔模型在解释物候(叶期物候, 花期物候)变化中贡献相对较小,能量模型和降水模型能够很好的解释物候(叶期物候, 花期物候)沿着纬度梯度变化的规律。(3)方差分解结果显示三个模型对花期物候和叶期物候变化的解释程度具有一定的相似性。三个模型的交互效应较高(33.7%,31.1%), 三个模型可以很好的解释物候（花期物候, 叶期物候）沿着纬度变化的规律, 可为农林业引种驯化提供科学依据。     

不同纬度阔叶红松林红松径向生长对气候因子的响应

运用树木年轮气候学方法,研究了不同纬度阔叶红松林红松径向生长趋势及其与气候因子的关系,以期揭示不同纬度红松径向生长对气候因子响应的差异以及气候变化影响下红松的动态特征、适应性及敏感性.结果表明: 不同纬度红松径向生长对当地气候因子的响应存在差异,最南部的白石砬子自然保护区红松径向生长与生长季的平均相对湿度呈显著正相关,与平均最高气温呈显著负相关.中部的长白山自然保护区的低海拔区域红松径向生长与生长季的水分因子(降水、相对湿度和帕尔默干旱指数PDSI)呈显著正相关,而与平均最高气温呈显著负相关;凉水自然保护区红松径向生长与生长季的水分因子(相对湿度和PDSI)呈显著正相关,与气温因子(平均气温和平均最高气温)呈显著负相关.而最北部的胜山自然保护区红松径向生长则与大部分月份的气温因子呈显著正相关.当年6月气候因子是影响所有纬度红松径向生长的关键气候因子,4个样地都与当年6月平均最高气温呈显著负相关.在气温不断上升的近40年,最南部的红松径向生长呈显著下降趋势,最北部呈显著上升趋势,中部的变化不显著.如果未来气温升高而降水不变,红松分布区可能缩小.     

大学校园植物物候格局及其气候驱动因子研究——以海南大学为例

植物的物候格局通常随时间而变化,展叶、开花和结实的出现时间和数量因年而异,或因事件而异,然而,热带地区的物候格局在很大程度上仍然是未知的。该研究利用海南岛海口市海南大学校园3年的物候监测数据,分析植物的展叶、开花、结实物候格局。对物候期与环境变量进行多重回归分析影响热带地区植物物候的主要气候因子。结果表明, 热带地区植物物候格局具有明显的季节性,展叶、开花和结实分别集中在4月—6月、4月—8月、5月—11月;影响展叶和开花物候格局的气候因子均为月均日照时长,每月结实物种数与气温相关,尤其是每月果实成熟物种数与月最低气温呈显著相关。不同功能群之间物候期存在差异,灌木展叶早于草本和乔木,风媒植物展叶早于虫媒植物,肉质果型植物展叶和果实成熟时间早于非肉质果型植物。乔木开花比草本和灌木早,非肉质果型植物开花时间比肉质果型植物早,风媒植物果实成熟早于虫媒植物。这些对将来预测热带物候事件具有重要意义。     

气候变暖对内蒙古地区小白杨物候的影响

基于1982—2006年内蒙古地区17个小白杨物候观测站的气温以及小白杨春季和秋季物候资料,对该区小白杨春季和秋季物候的变化趋势进行了研究,分析了物候期变化与气候变暖的关系,并利用逐步回归方法建立了小白杨始花期和落叶期变化的预估模型.结果表明：1982—2006年间,研究区气温呈增加趋势,该区小白杨春季物候呈提前趋势,秋季物候呈延后趋势;小白杨始花期与冬、春季气温呈负相关,主要影响因子为3—4月的平均气温;落叶期与秋季气温呈正相关,主要影响因子为8—10月的平均气温;根据气候变化国家评估报告,未来内蒙古地区春、秋季平均气温分别升高1.5 ℃～5.4 ℃和1.2 ℃～4.4 ℃,小白杨始花期将提前3.9～17.8 d,落叶期将延后3.0～12.4 d.     

不同产地苦楝苗期生长节律研究

苦楝在我国分布广泛,具有丰富的遗传变异性。为进一步做好苦楝种源筛选和良种选育工作,该文对不同产地苦楝实生苗生长性状和各阶段的生长特点进行了比较分析,初步揭示了苦楝苗期生长规律。以15个产地的1年生实生苗为试材,对苗高、地径、复叶生长及生物量积累等生长性状进行了观测分析,并用Logistics方程对生长节律进行了拟合。结果表明:(1)不同产地苦楝苗高、地径生长差异均达显著水平,根生物量、茎生物量及复叶相关性状差异均达极显著性水平;(2)苗高和地径生长均呈现慢-快-慢的S型生长规律,且均存在2次生长高峰,与苗高生长高峰出现时间相比,地径生长高峰出现时间较晚;(3)Logistic拟合方程的R²为0.976～0.994,均达到极显著相关水平,说明可用Logistic方程拟合苦楝的生长节律;(4)总体上地径速生期较苗高速生期长20～30 d,北方产地苗高和地径进入速生期和结束速生期的时间均早于南方产地,速生期苗高和地径累积生长量均超过总生长量的60%;(5)各生长指标均与纬度负相关,苗高、生物量及复叶面积与经度正相关,其他指标与经度负相关。综上结果表明,苦楝为全期生长型树种,各生长性状在产地间达显著差异水平,生长受纬度和经度双重控制,以纬度控制为主。     

岭南槭叶色表现与色叶性状研究

岭南槭自然分布于泛珠三角低山丘陵区,春季新叶与秋冬变叶期色彩艳丽,可广泛用于岭南地区城镇绿化。选取广东省南岭国家级自然保护区、黑石顶省级自然保护区和深圳大鹏半岛国家地质公园七娘山的岭南槭天然群落为对象,开展其色叶期物候观测,量化其年周期叶片色彩值,比较研究其最佳观赏期,探究影响叶色表达的关键因子。结果显示：（1）不同地区岭南槭色叶期具有差异,南岭最佳观赏期为11月份,黑石顶为11月上旬~12月上旬,七娘山为12月份;（2）岭南槭色叶特征和土壤理化性质不同样地间差异显著（P<0.05）;（3）岭南槭红叶始期与经度、土壤速效K含量显著正相关,最大色差值与速效K呈极显著正相关,最佳观赏期持续时间与海拔、有效Cu显著负相关,最佳观赏期的最大色差值与纬度极显著负相关,红叶期持续时间与全K呈显著负相关,与有效P、有效Cu呈极显著负相关;（4）岭南槭红叶最佳观赏期由北到南逐渐延迟,海拔、经度、纬度较低,土壤中全K、有效P、有效Cu的含量较低,速效K含量较高,有利于岭南槭红叶景观的表达。     

基于生态地理分区的大兴安岭植被物候时空变化

植被与气候的关系十分密切,植被物候可作为全球气候变化的指示器.大兴安岭位于我国最北部,对气候变化较为敏感,研究该区植被物候的时空变化对评估全球变化对陆地生态系统的影响具有重要意义.依据中国生态地理区划图,将大兴安岭划分为4个生态研究区域,本文利用GIMMS NDVI 3g遥感数据集分析1982—2012年大兴安岭整体及各生态地理分区植被物候变化.结果表明: 研究期间,所有分区植被生长季开始日期均表现为提前趋势,生长季结束日期均表现为推迟趋势.植被物候对气候因子变化敏感,尤其是对气温的敏感程度高于降水,其中,北段山地落叶针叶林区植被生长季开始日期与春季温度呈显著负相关;除南段草原区外,其他3个分区植被生长季结束日期均与秋季降水呈显著负相关.从整体来看,植被物候随海拔、纬度的变化趋势明显.     

文冠果人工种群的果实发育与落花落果特性研究

以甘肃定西生长的文冠果为对象,探讨了文冠果果实发育特征及落花落果规律。结果表明：（1）文冠果果实生长发育历经约2.5个月,生长发育主要在花期后的40 d内。果实发育特点为：在花期过后的10 d内生长最快,增长率达193%,此后一月仍保持较快的生长速度,月增长率达120%,而最后一月生长比较缓慢,月增长率仅为7%,整个发育期内横径发育速度一直大于纵径;（2）文冠果落花落果主要发生在果实生长发育的初期,且落花落果率高,达94.65%(落花率5.74%,落果率88.91%）,坐果率低,只有5.35%。其落果特点为：落果是一个持续的过程,自花期过后果实膨大到成熟一直在落果,但也存在一个落果的高峰期,即花期过后的10 d内,落果最严重,落果率约达40%。研究认为,从保花保果的角度考虑,开花末期是文冠果水肥管理的重点时期。但从文冠果开花过于繁茂和可孕花分布过于集中而大量消耗树体和顶花序养分,从而造成严重的落花落果的现实考虑,应在开花末期和幼果期疏花疏果或任其自然落花落果,但均应加强果实发育中后期的水肥管理,从而提高坐果率。     

云南元江干热河谷木本植物的物候

在中国西南干热河谷的典型地段——元江干热河谷,连续3年观测了32种木本植物的枝条生长、叶片动态、花期、果期和果实类型。这些植物的枝条生长方式可以分为连续生长、枝条枯死、陡长和间歇生长4个类型。其中连续生长型占优势,包括13种植物,它们的枝条在雨季连续不断伸长。9种植物雨季的枝条伸长与连续生长型的相似,但它们顶部的枝条在旱季末期出现枯死现象。6种植物属于陡长型,在2周内完成抽枝,且一年只抽一次枝。4种植物属于间歇生长型,枝条在雨季来临后伸长一段时间,然后生长停滞,过一段时间后再接着伸长。从叶片物候类型看,元江干热河谷植被以落叶植物占优势。落叶植物中冷凉旱季（11月～2月）落叶植物占优势（19种）,而干热旱季（3—4月）落叶植物很少（4种）。除红花柴（Indigofera pulchella）和狭叶山黄麻（Trema angustifolia）从雨季中期开始脱落叶片外,其它30种植物从雨季末期开始脱落叶片,落叶期至少延续3个月以上。常绿植物脱落近1／3～1／2的当年生叶片。共有6种植物能在旱季末期长出新叶。常绿植物的叶面积、单个枝条上的总叶面积和枝条承载（总叶面积／枝条长度）比落叶植物小。虽然一年四季都有不同植物开花和结果,但多数植物（29种,占观测树种的91％）的花期集中在旱季和雨季初期,而果实（种子）成熟期从雨季末期延续到旱季末期和下个雨季初期。果实多为核果。     

Flowering and Fruiting Patterns in a Subtropical Rain Forest,Taiwan

Reproductive patterns of tropical and temperate plants are usually associated with climatic seasonality, such as rainfall or temperature, and with their phylogeny. It is still unclear, however, whether plant reproductive phenology is influenced by climatic factors and/or phylogeny in aseasonal subtropical regions. The plant reproductive phenology of a subtropical rain forest in northern Taiwan (24°45′ N, 121°35′ E) was monitored at weekly intervals during a 7‐yr period (2002–2009). The flowering patterns of 46 taxa and fruiting patterns of 26 taxa were examined and evaluated in relation to climatic seasonality, phylogenetic constraints, and different phenophases. Our results indicated that most of the studied species reproduced annually. Additionally, both community‐wide flowering and fruiting patterns exhibited distinct annual rhythms and varied little among years. The community flowering peak matched seasonal changes in day length, temperature, and irradiance; while the community fruiting peak coincided with an increase in bird richness and the diet‐switching of resident omnivorous birds. In addition, phylogenetically closely related species tended to reproduce during the same periods of a year. Neither the mean flowering dates nor seasonal variation in solar radiation, however, was related to the fruit development times. Our results indicate the importance of abiotic, biotic, and evolutionary factors in determining the reproductive phenology in this subtropical forest.     

甜椒始花期吸收的氮素在体内的动态分配规律

 通过水培试验,利用15N示踪技术研究了甜椒(Capsicum annuum L.)始花期吸收的氮素在体内的动态分配规律。结果表明：甜椒营养器官干物质积累动态呈快速直线增长趋势,而果实则从盛采前期开始 超过其它器官。根与果实含氮量从始采期开始一直维持在同一水平;叶片中氮的含量则随生长发育而不断下降。在果实盛采期,叶片、果实和根中的氮素含量差异不明显,但是均比茎和侧枝高两倍。甜椒植株各器官的氮素积累动态与干物质积累动态相似。在始花期通过根吸收的大部分标记态氮首先分配、贮存在叶片中,吸收后第二周发现有１/2的标记态氮运转到了植物的新生部分,至吸收后的第四周标记态氮运转显著下降,但是,在吸收后的第六周仍然发现有小部分标记态氮运转到了新生部分。说明新近吸收的氮素在甜椒体内的再运转相对容易,其再利用率也高,随着在植物体内某器官存在时间的延长其再利用率逐渐降低。在整个果实收获期间,甜椒不同器官之间以果实对氮素的竞争力最强。在整株水平上,始花期吸收的标记态氮从营养器官向生殖器官的运转,既受到氮素竞争库（果实）强度和容量的影响,也受到时间因素的制约。     

Climatic factors governing plant phenological phases along a Norwegian fjord

In the present project, the time of leaf budding and flowering, and partly also of fruit ripening, was studied over 3 years in different cultivated and native plants on a gradient along a western Norwegian fjord about 300 km long, from oceanic to relatively continental regions. In the plants investigated, flowering of the red currant was most strongly favoured by oceanic conditions in the outermost part of the fjord. On the other hand, flowering of the apple was earliest in the middle district, as were flowering of the common lilac and raspberry, while differences were small between the districts for flowering of the plum and pear. In the inner district, leaf budding of the apple was about 1.5 weeks earlier than flowering of the red currant, while these two phenophases, on average, occurred on the same day in the oceanic district. The time from 1 April to flowering was generally lengthened by increased precipitation in the pear, apple, lilac and raspberry, but not in the red currant and plum. By contrast, the period from leaf budding to flowering was significantly shortened in the plum by high precipitation. The present studies also indicated that leaf budding of the birch was favoured by the high minimum temperature and the relatively high precipitation normally found in the oceanic district. Partial correlations showed that increased precipitation delayed the flowering of both rowan and bird cherry trees; there was also a week effect on bud break in the same two species. The clear conclusion of the present study, therefore, is that various plant species react differently to various climatic factors ("phenological interception"), even in different phenophases within the same species. This means that the various species are best fitted to certain climatic regions and should preferably be planted there if other growth factors are satisfactory.     

Floral resources,pollinators and fruiting in a threatened tropical deciduous tree

Aims Nothapodytes nimmoniana (Family Icacinaceae) is a deciduous tree species distributed in Asia facing severe population decline. Wood chips from the tree are a source of camptothecin, a globally sought-after alkaloid with cancer-treating properties, and are harvested unsustainably in natural forests. We studied the pollination ecology of the species and asked if there are constraints in pollination and fruiting success in its natural populations. We also discuss the potential effects of wood extraction on pollinators and reproductive success in the population.Methods The study was carried out during the flowering season in two populations with varying exploitation levels, both located in the Protected Area Network in the Western Ghats of Karnataka State. We assessed floral resource availability and measured pollinator diversity and activity in the canopy from the perspective of the biology of the species. We quantified pollinator abundance and percent fruit set as a function of population density.Important findings Flowers belong to the fly pollination syndrome and are open to visits by generalists such as Apis dorsata and Trigona iridipennis. Fruiting success did not vary between exploited and unexploited sites, but there was a significant difference in pollinator assemblage. In a lean male flowering year, fruit set was low, suggesting pollen limitation in the population. No fruiting was recorded in the second year at the site where trees were felled soon after the flowering period. We argue that when male floral resources are altered in exploited populations, pollinators of generalist nature may show a shift in foraging pattern. Also, generalist plants may be as susceptible to pollination loss as are specialist plants. The need for outcrossing in the species would probably exacerbate this vulnerability.     

In Loquat (Eriobotrya japonica Lindl.) Return Bloom Depends on the Time the Fruit Remains on the Tree

In loquat (Eriobotrya japonica Lindl.), the comparison of fruiting trees and defruited trees carried out covering a range of developmental fruit stages reveals a significant reduction in flowering due to fruit from its early stage of development, being higher when it changes color and becomes senescent, which coincides with the floral bud inductive period. This effect occurred both at the tree and at the shoot level. Furthermore, although current shoots almost always develop into panicles, those from fruiting trees develop fewer flowers, suggesting that fruit also affects at the floral bud level. In our experiment, the gibberellin concentration at the floral bud inductive period was significantly higher in bark tissues (periderm, cortex and phloem tissues) of fruiting trees, compared with defruited trees that tend to flower more. The lower concentration of IAA in the bark tissues of defruited trees also contributes to increase their flowering intensity. On the contrary, the zeatin concentration was higher. Accordingly, at bud burst, the IAA/zeatin ratio, an indication of effect on flowering, was significantly higher for fruiting trees. Some disruption in the nitrate reduction process in fruiting tree was also observed. The process of floral bud induction and differentiation was not associated with either reducing or translocating and reserve carbohydrate concentration. Hence, loquat flower intensity depends on the time the fruit is maintained on the tree. The intensity is affected indirectly, by reducing the number of shoots, and directly, by reducing the number of flowers per panicle, and these effects are linked to endogenous plant hormone contents.     

Long-term temporal changes of plant phenology in the Western Mediterranean

Plants are altering their life cycles in response to current climatic change around the globe. More than 200 000 records for six phenological events (leaf unfolding, flowering, fruit ripening, fruit harvesting, leaf falling and growing season) of 29 perennial species for the period 1943–2003 recorded throughout Spain provide the longest temporal and the broadest spatial assessment of plant phenology changes in the Mediterranean region. The overwhelming majority of the 118 studied phenophases shifted their dates in recent decades. Such changes differed among phenological events. Leaf unfolding, flowering and fruiting are markedly advancing (?0.48, ?0.59 and ?0.32 days yr^?1, respectively), but only since the mid‐1970s. Anemophilous have advanced more days their flowering than entomophilous. However, some species have delayed and others have advanced their leaf falling dates and as a result only a weak shift was observed in this event for the whole of the studied species (+0.12 days yr^?1). The growing season lengthened by 18 days, which implies an increase of 8% in the life of annual leaves. Such an increase was achieved mainly through the advance of leaf unfolding dates in the spring, one of the most productive times of year for vegetation in the Mediterranean. Shifts in the plant calendar were accompanied as well by long‐term changes in the range of onset dates in 39% of studied phenophases. Leaf unfolding, flowering and growing season tended to reduce spatial variability, reflecting a faster and more synchronized onset (or duration) of phenophases across the study area. Changes in spatial variability may aggravate calendar mismatching with other trophic levels resulting from changes in dates. Because temporal responses differed markedly among species, calendar guilds of plants have changed, which suggests alterations of interspecific relationships in plant communities from Mediterranean ecosystems.     

Seasonal Patterns of Flowering and Fruiting in a Dry Tropical Forest in Jamaica1

Tropical dry forests occupy more area and are more endangered than rainforests, yet their regeneration ecology has received less study and is consequently poorly understood. We recorded the flowering and fruiting phenology of a tropical dry forest in Jamaica over a period of 26 mo within ten 15 × 15‐m plots. Community‐wide recruitment reached a maximum in the wet season, whereas no recruitment occurred during the dry season. We observed a unimodal peak in rainfall and fruit production, and the periodicity and intensity of seed production were significantly correlated with rainfall seasonality (the optimal time for germination). Flowering at the community and system levels lagged behind a significant increase and subsequent decrease in rainfall by 7 and 3 mo, respectively, indicating that the dominant factor controlling flowering periodicity is the passage of the major (4‐mo long) rainy season and changes in soil moisture conditions. Fruiting lagged behind flowering by 2 mo and a significant increase in fruiting occurred 2 mo prior to a significant increase in rainfall. At the population level, a correspondence analysis identified a major dichotomy in the patterns of flowering and fruiting between species and indicated two broad species groups based on their time of peak fruiting and the number of times they were in fruit. These were either individuals which were usually in peak fruit 1–2 mo prior to the start of the major rainy season or those that were in fruit more or less continuously throughout the year with no peak fruiting time. This study supports the view that seasonal variation in rainfall and hence soil water availability constitutes both the proximate and the ultimate cause of flowering periodicity in tropical dry forests.     

Diversity of flowering and fruiting phenology of trees in a tropical deciduous forest in India

BACKGROUND AND AIMS: In the dry tropics, vegetative phenology varies widely with tree characteristics and soil conditions. The present work aims to document the phenological diversity of flowering and fruiting with reference to leafing events in Indian dry-tropical tree species. METHODS: Nine tree species, including one leaf-exchanging and eight deciduous showing varying leafless periods, were studied. Monthly counts of leaves, flowers and fruits were made on 160 tagged twigs on ten individuals of each species for initiation, completion and duration of different phenological events through two annual cycles. KEY RESULTS: Variation in flowering relative to leaf flushing (which occurred just prior to or during a hot, dry summer) revealed five flowering types: summer flowering (on foliated shoots), rainy-season flowering (on foliated shoots following significant rains), autumn flowering (on shoots with mature leaves), winter flowering (on shoots undergoing leaf fall) and dry-season flowering (on leafless shoots). Duration of the fruiting phenophase was shortest (3-4 months) in dry-season and winter-flowering species, 6-9 months in rainy-and autumn-flowering species, and maximum (11 months) in summer-flowering species. A wide range of time lag (<1 to >8 months) between the start of vegetative (first-leaf flush) and reproductive (first-visible flower) phases was recorded in deciduous species; this time lag was correlated with the extent of the leafless period. A synthesis of available phenological information on 119 Indian tropical trees showed that summer-flowering species were most abundant (56 % of total species) amongst the five types recognized. CONCLUSIONS: The wide diversity of seasonal flowering and fruiting with linkages to leaf flush time and leafless period reflect the fact that variable reproductive and survival strategies evolved in tree species under a monsoonic bioclimate. Flowering periodicity has evolved as an adaptation to an annual leafless period and the time required for the fruit to develop. The direct relationship between leafless period (inverse of growing period) and time lag between onset of vegetative and reproductive phases reflects the partitioning of resource use for supporting these phases. Predominance of summer flowering coupled with summer leaf flushing seems to be a unique adaptation in trees to survive under a strongly seasonal tropical climate.