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1.
小熊猫对食物的选择和觅食对策的初步研究 总被引:9,自引:6,他引:9
作者在四川马边大风顶自然保护区对小熊猫的食物选择和觅食对策进行了研究,结果表明小熊猫喜欢选择在坡度较大,林木郁闭度适中,竹子生长良好,竹子密度适中,离水源较近的杜鹃-大叶筇竹林中活动觅食,喜食大叶筇竹竹叶和竹笋,偶食白背玉山竹竹叶和竹笋,不食刺竹,并且对大叶筇竹竹龄和竹叶也有明显的选择,喜食1、2年生竹或刚萌生的幼嫩竹叶。环境每1m^2的大叶筇竹竹叶能提供2850、09KJ的能量,若按1%的利用率 相似文献
2.
为了探讨圈养大熊猫主食竹食谱组成及主要影响因素,并为圈养单位提供科学合理的食物营养配比和饲养管理建议。本研究通过对成都大熊猫繁育研究基地10 只成年大熊猫4 年(2009. 03 -2013.02)的饲养数据,3只成年大熊猫1 年(2012. 07 -2013. 06)的觅食行为观察数据,以及投饲的3 种竹笋和5 种主食竹常规养分和总黄酮含量的统计分析。结果发现,基地圈养大熊猫偏好竹笋,喜食巴山木竹叶、白夹竹茎和苦竹茎,随机采食箬竹叶和刺竹茎;基地大熊猫根据投饲竹种类和季节的变化,形成了较为稳定的食谱组成;对投饲竹各部位成分比较分析发现,投饲竹养分含量的变化呈现出一定的规律性:其中粗蛋白、粗脂肪、蛋白质和能量比都以竹叶最高,竹枝次之,竹茎最低;干物质和粗纤维的含量则以竹茎最高,竹枝次之,竹叶最少;竹茎和竹枝呈现钙少磷多的现象,而竹叶则是钙多磷少;各投饲竹不同部位总黄酮含量以叶中最高,枝中其次,茎中最低。研究结果表明,圈养大熊猫主食竹食谱的选择遵循能量和营养学的规律,选择适口性强、营养价值高的食物假说。 相似文献
3.
佛坪自然保护区食竹鸟兽种类的初步调查 总被引:1,自引:0,他引:1
1991~2004年采用检查死亡个体的胃或嗉囊内容物、新鲜粪便和在野外直接观察动物采食的3种方法,在陕西佛坪国家级自然保护区对食竹的鸟兽种类进行了初步调查。巴山木竹和秦岭箭竹是大熊猫采食的主要食物资源。除大熊猫外,采食这两种竹的鸟兽有38种,隶属6目14科,其中鸟类9种,兽类29种。大量采食、中等采食和少量采食竹类的物种分别为1种、5种和33种,所占比例分别为2.6%、12.8%和84.6%。39种鸟兽均采食竹笋,其中32种只采食竹笋。黑熊和野猪是食竹笋量比较大的大型兽类,羚牛、鬣羚和斑羚3种牛科动物全年都采食竹类,其中以羚牛对竹叶的采食量最大。这些食竹鸟兽一方面直接与大熊猫竞争食物资源,特别是竹笋,另外也会间接地影响大熊猫对竹类的利用。 相似文献
4.
本文以2010—2020年15只母兽带仔野化培训的大熊猫幼仔为研究对象,基于红外视频监控系统观察和音频颈圈解译获得的行为资料、GPS颈圈跟踪定位采集的粪样数据,分析了野化培训大熊猫幼仔的行为发育进程和食性转换特征。结果表明:随着野化培训大熊猫幼仔的生长发育,与觅食和警戒相关的行为得到充分发育,且具有较强的时间关联性,包括食乳、爬行、走动、玩耍物品、爬树、咬玩竹子、饮水和采食竹子等。8~10月龄的大熊猫幼仔开始取食竹子,其发育性食性转换过程划分为3个阶段:食乳期(1~7月龄)、食母乳—食竹子转换期(8~28月龄)和食竹期(29~39月龄),其中转换期细分为关键期(8~18月龄)和过渡期(19~28月龄)。从统计检验来看,不同食性阶段间差异显著;过渡期的大熊猫幼仔可离开母兽独立生活,此阶段大熊猫幼仔食物组分比例与食竹期相比无显著差异。野化培训大熊猫幼仔的季节性食性转换规律与带仔母兽和野生大熊猫具有相似的格局,即春季主要取食竹笋,夏、秋季则以嫩竹茎和竹叶为食,冬季采食竹叶与竹茎。 相似文献
5.
2013年3月至2014年2月,在秦岭南坡观音山自然保护区大坪峪颜家沟内选取一群半野生川金丝猴的成年个体作为研究对象,采用瞬时扫描取样法收集其觅食的食物类型数据,目的是为该猴群建立食谱,并通过对比不同季节内觅取的食物组成差异探讨秦岭南坡川金丝猴如何应对喜食食物的季节性缺乏。结果表明:秦岭南坡川金丝猴共采食53种植物(包括34种乔木、13种灌木、6种藤本植物)和4种大型真菌,分别占取食植物组成的64.3%、25.3%、8.0%和2.2%,春、夏、秋、冬季节取食种类和多样性指数分别为20种(3.93)、19种(3.73)、21种(3.87)和25种(4.12)。在秦岭南坡川金丝猴的食物组成中,地衣占总觅食记录的22%;树叶占20%,其中嫩叶9%和成熟叶11%;种子、树皮、芽苞、果实和叶柄分别占16%、15%、11%、 9%和7%。该猴群觅取的植物部位具有明显的季节性差异。春季,对树皮和芽苞的觅食量较高,分别为28%和25%;夏季,增加了对成熟叶的采食量(29%),而减少了芽苞的觅取量(5%);秋季,以取食种子和果实为主,分别占总觅食的48% 和16%;冬季,地衣的采食量达到最大值(41%)。觅食的食物组成与食物的可获得性呈正相关性(R = 0.984, P < 0.01),这与大多数叶猴的适应策略类似,在喜食食物短缺的冬季,它们选择更多的地衣和树皮为食,同时它们采食的种类和食物多样性也有相应增加。 相似文献
6.
大熊猫在野外食物选择的广泛性远大于圈养个体。均衡饮食对于大熊猫异地保护至关重要,其中包括适当水平的微量营养素。评估圈养大熊猫不同采食期的营养状况,有助于构建科学的大熊猫饲养策略。本研究选取7只健康成年圈养大熊猫,依次饲喂竹叶(竹叶采食期)和竹笋(竹笋采食期)。竹叶采食期进行3次饲喂实验,竹笋采食期进行2次饲喂实验,每次饲喂实验持续3 d,每次饲喂实验间隔28 d。实验期间记录大熊猫的日采食量,测定竹子的维生素含量并查阅其矿物元素含量,从而比较大熊猫在不同采食期的维生素和矿物元素日摄入量。各采食期结束时采集大熊猫血样,测定血清中13种维生素和10种矿物元素水平。结果发现:与竹叶相比,竹笋的VA、VE、VK1、烟酸、吡哆醛及吡哆醇含量显著下降,VB5和VB12含量显著增加(P<0.05)。与竹叶采食期相比,竹笋采食期大熊猫的VE、VK1、Ca、Fe、Cu和Mn日摄入量显著降低,VB5、VB6 相似文献
7.
作者于2004年7~10月采用所有事件取样法(All-occurrence recording)和时间数据收集0-1取样法,对13只圈养大熊猫觅食行为观察,发现:圈养大熊猫食物中竹子占77%、其它占23%;幼体很少吃竹子,亚成体食竹量稍多于成体,亚成体觅食竹茎带高于成体,成体吃竹叶的量大于吃竹茎的量,偏好于吃竹叶;气温高于26℃后,大熊猫觅食频率有所下降,气温下降到22℃以下时,觅食频率开始上升;9:30~11:30和14:30~15:30为大熊猫觅食竹子的高峰期,与人为投食时间明显有关;圈养大熊猫日食竹时间占总时间的20%,其它活动时间占17%,休息时间占63%,明显短于野生大熊猫的觅食时间。以上观察结果对改进和完善圈养大熊猫的饲养管理具有重要的参考价值。 相似文献
8.
马边大风顶自然保护区大熊猫对竹类资源的选择利用 总被引:18,自引:1,他引:17
本文对凉山山系大熊猫对竹子资源选择利用进行了研究,发现对不同的竹类有不同程度的选择性。最喜食大叶筇竹和白背玉山竹,几乎不选择刺竹子;就大叶筇竹而言,喜食基径大于10mm的幼竹竹茎,特别喜食基径大于18mm的竹笋;就白背玉山竹而言,喜欢选择基径大于12mm的竹茎和基径大于16mm的竹笋,但对白背玉山竹的老嫩无明显选择。 相似文献
9.
高原鼠兔冬季的食物选择 总被引:3,自引:1,他引:2
本文采用胃内容物镜检分析法,对高原鼠兔在矮嵩草草甸、垂穗披碱草草甸和杂类草草甸三种类型栖息
地中的主要食物组成进行了比较分析,旨在探讨三类栖息地不同食物资源状况对高原鼠兔食物组成的影响,以
及高原鼠兔在食物匮乏的冬季的觅食对策。研究结果表明:高原鼠兔在冬季主要选食弱小火绒草和铺散亚菊,
甘肃棘豆、垂穗披碱草和长茎藁本也是冬季食物主要组成部分。在冬季食物资源较为匮乏的情况下,高原鼠兔
选食的主要植物种类相对较多,且不同植物比例变化明显,说明高原鼠兔对食物具有一定的选择性。在矮嵩草
草甸中,其食物组成依次为铺散亚菊(16. 2% ) > 弱小火绒草(11. 5% ) > 甘肃棘豆(11. 3% ) > 大籽蒿
(9. 7% ) > 早熟禾(7. 6% ) > 长茎藁本(7. 5% ) > 垂穗披碱草(5. 5% )等7 种,占其食物的69. 3% ;在垂
穗披碱草草甸,其主要食物组成依次为垂穗披碱草(15. 8% ) > 甘肃棘豆(14. 7% ) > 弱小火绒草(14. 5% )
> 铺散亚菊(14. 2% ) > 早熟禾(7. 8% ) > 长茎藁本(6. 9% ) > 锥果葶苈(6. 2% )等7 种,占其食物的
80. 1% ;在杂类草草甸中,其主要食物组成依次为铺散亚菊(20. 8% ) > 长茎藁本(20. 6% ) > 大籽蒿
(9. 9% ) > 弱小火绒草(9. 8% ) > 锥果葶苈(6. 5% ) > 圆齿狗娃花(5. 5% )等6 种,占选食食物的73. 1% 。
不同栖息地之间食物组成比较分析结果表明,在冬季食物资源匮乏的情况下,栖息地类型不同对高原鼠兔食物
组成的影响较小,杂类草构成了它们的主要食物,这可能是由食物质量决定的,而不同栖息地中喜食植物可利
用量是决定鼠兔食物组成的主要因子,进一步验证了食物可利用量和质量决定植食性小哺乳动物食物选择模式
的假设。 相似文献
地中的主要食物组成进行了比较分析,旨在探讨三类栖息地不同食物资源状况对高原鼠兔食物组成的影响,以
及高原鼠兔在食物匮乏的冬季的觅食对策。研究结果表明:高原鼠兔在冬季主要选食弱小火绒草和铺散亚菊,
甘肃棘豆、垂穗披碱草和长茎藁本也是冬季食物主要组成部分。在冬季食物资源较为匮乏的情况下,高原鼠兔
选食的主要植物种类相对较多,且不同植物比例变化明显,说明高原鼠兔对食物具有一定的选择性。在矮嵩草
草甸中,其食物组成依次为铺散亚菊(16. 2% ) > 弱小火绒草(11. 5% ) > 甘肃棘豆(11. 3% ) > 大籽蒿
(9. 7% ) > 早熟禾(7. 6% ) > 长茎藁本(7. 5% ) > 垂穗披碱草(5. 5% )等7 种,占其食物的69. 3% ;在垂
穗披碱草草甸,其主要食物组成依次为垂穗披碱草(15. 8% ) > 甘肃棘豆(14. 7% ) > 弱小火绒草(14. 5% )
> 铺散亚菊(14. 2% ) > 早熟禾(7. 8% ) > 长茎藁本(6. 9% ) > 锥果葶苈(6. 2% )等7 种,占其食物的
80. 1% ;在杂类草草甸中,其主要食物组成依次为铺散亚菊(20. 8% ) > 长茎藁本(20. 6% ) > 大籽蒿
(9. 9% ) > 弱小火绒草(9. 8% ) > 锥果葶苈(6. 5% ) > 圆齿狗娃花(5. 5% )等6 种,占选食食物的73. 1% 。
不同栖息地之间食物组成比较分析结果表明,在冬季食物资源匮乏的情况下,栖息地类型不同对高原鼠兔食物
组成的影响较小,杂类草构成了它们的主要食物,这可能是由食物质量决定的,而不同栖息地中喜食植物可利
用量是决定鼠兔食物组成的主要因子,进一步验证了食物可利用量和质量决定植食性小哺乳动物食物选择模式
的假设。 相似文献
10.
黑叶猴食物组成及其季节性变化 总被引:2,自引:0,他引:2
对灵长类来说,喀斯特石山生境是一种比较独特的生活环境。喀斯特森林具有生物量低,物种多样性高的特点,生活于其中的灵长类的食物资源受环境的影响强烈,有明显的季节性变化。黑叶猴(Trachypithecus francoisi)是生活在喀斯特石山的特有灵长类动物。在食物资源波动较大的石山生境中,黑叶猴如何在食物匮乏时期获得食物?是否采取了大多数灵长类的应对策略,还是采用适应喀斯特环境的特殊对策?为了回答这些问题,2005年9月至2006年8月,在广西弄岗国家级自然保护区选择一群黑叶猴作为观察对象,采用瞬时扫描取样法收集相关的食性数据。通过比较不同季节食物组成的差异来探讨黑叶猴如何应对喜食食物(嫩叶、果实)的季节性缺乏的问题。结果表明:黑叶猴共采食92种植物,其中乔木和灌木38种,藤本植物52种,草本植物1种,寄生植物1种。猴群平均每月采食食物22.8种(6-34种),月平均食物多样性指数为2.5(1.6-3)。在弄岗黑叶猴的食物组成中,树叶占总觅食记录的71%,其中嫩叶46.9%,成熟叶24.1%的;果实、花和种子分别占13.2%、6.3%和4.3%;其他食物类型占5.4%,分别包括茎1.8%,叶柄1.1%,未知部位2.5%。黑叶猴的食物组成具有明显的季节性差异。在旱季,平均月食物种类和食物多样性指数分别为29.3和2.8,明显高于雨季的16.2和2.1。在雨季,嫩叶在食物中的比例明显高于旱季(61.5%相对32.3%);在旱季,猴群对成熟叶的采食比例明显高于雨季(39.4%相对8.9%),且在该季节才利用种子作为食物,占食物组成的8.6%。黑叶猴的食物组成受食物可获得性的影响。主要表现为嫩叶在食物中所占的比例与其可获得性有显著的正相关关系(r=0.865,n=12,P=0.000)。另外,当成熟叶和果实的可利用性降低时,黑叶猴的食物多样性指数提高(成熟叶:r=-0.602,n=12,P=0.039;果实:r=-0.716,n=12,P=0.009)。黑叶猴在嫩叶丰富的雨季,它们采食更多的嫩叶;而在喜食性食物短缺的旱季,它们采取选择更多种类的成熟叶和种子为食,同时它们采食的种类和食物多样性也相应地增加。这与大多数叶食性灵长类的适应策略相似。 相似文献
11.
Seasonal energy intake and digestion of bamboo by red pandas were measured in energy balance trials at the field station at an altitude of 3,100 m in Yele Natural Reserve, Mianning County of Sichuan Province, Peoples Republic of China. Two‐week trials were conducted at monthly intervals by feeding animals with only natural bamboo browse, Bashania spanostachya, from May to November 1995. Results demonstrated that energy intake, digestible energy, and digestibility differed significantly among seasons and diets. Energy digestibilities were high in summer‐autumn, intermediate in spring, and low in winter. These variations correlated positively with the nutrient contents of bamboo. The daily metabolic energy requirement measured varied from 2,603.3 kJ in the spring to 3,139.8 kJ in the summer‐autumn to 2,740.8 kJ in the winter. The results also showed that shoots were more easily digested than leaves and exhibited the highest digestibility. Restricted by the capacity of digestive tracts, red pandas poorly utilized the energy provided by bamboo as indicated by the lower energy digestibility (averaging 26.47% for leaves and 44.08% for shoots among the seasons). To fulfill their daily energy requirements, red pandas ingested a large amount of energy from bamboo leaves, which varied from 10,145.8 kJ in the spring, 12,045.1 kJ in the summer‐autumn, and 12,276.9 kJ in the winter to maximize the rate of energy intake. Zoo Biol 19:27–33, 2000. © 2000 Wiley‐Liss, Inc. 相似文献
12.
Red panda behaviour was studied in the Wolong Reserve, Sichuan, China to understand better the ecology of this herbivorous member of the Carnivora. Leaves of montane bamboo were the most common food in all months (93.7% of 791 droppings), supplemented in spring with bamboo shoots, and in late summer with arboreal fruits. Home-range estimates by radiotelemetry for one adult female (94 ha) and one adult male (111 ha) most closely approximated allometrically-predicted range size for omnivores. Pandas were active45–49% of the time, with highest levels in April, and, for the female in summer when lactating. Activity was higher in daylight than at night, especially in summer, coincident with arboreal foraging. The hypothesis that pandas rest in direct sunlight in winter to minimize heat loss while reducing peripheral circulation, was inferentially supported by their spending significantly more time resting on clear compared to overcast winter days. The red panda's anatomy, diet and low metabolic rate suggest an arboreal folivorous lineage incorporating terrestrial foraging to capitalize on a super-abundant food resource–bamboo. Energy content of the annual recruitment of bamboo leaves within home ranges was substantially greater than annual energy requirements predicted allometrically. Gross food availability was not limiting to the radio-collared pandas, but may have been so in unoccupied habitats with a lower bamboo density following the bamboo die-back. Maternity den trees are probably a limiting resource in clearcut and deciduous forest habitats. 相似文献
13.
拐棍竹是卧龙野生大熊猫春季的主要食物。2014-2016年,从设置的3条固定样线中我们发现了当地野生大熊猫有分段取食拐棍竹笋的现象,且没有到放牧活动和人为干扰严重的河谷区域取食竹林内的拐棍竹笋。它们首先在海拔较低( 2 100 m左右)、新笋发育较早且人为干扰不严重的区域觅食,当这些区域的新笋普遍超过2 m高度时会向海拔较高处迁移。大熊猫优先选择有较高比例粗大竹笋的区域作为觅食场所,且当觅食斑块内新笋普遍较小时对粗笋有倾向性选择(P<0.05),但当环境中的新笋质量较好时,选择性有所降低(P>0.05)。大熊猫在新笋质量较好的觅食斑块中取食率较高,在海拔较高处因竹笋的基径较小所以取食率较低(F=20.12, P<0.05)。大熊猫取食新笋所留残桩高度与周边竹笋的高度呈正比(r=0.50, P<0.001)。为保证大熊猫在新笋期的觅食活动免遭干扰,管理者应该在这一时期严格限制大熊猫活动频繁区域的人为干扰。 相似文献
14.
The red panda Ailurus fulgens Cuvier, 1825 is endemic to the Himalayan-Hengduan Mountains. Many of its ecological traits are still poorly understood although
important from a scientific standpoint as a highly specialized bamboo feeder. To understand its food habits and space-use,
we carried out a field study from April 2002 to May 2003 in Fengtongzhai Nature Reserve, China. The results showed that red
pandas almost exclusively fed on Bashania faberi, but not on Yushania brevipaniculata in the study area. Besides differences in nutritional quality, accessibility to food items is perhaps another factor affecting
their utilization of bamboo species. B. faberi leaves are the highest in crude protein, being the primary year-round food source; new shoots and fruits of Sorbus, and Rubus are nutritious and digestible, seasonally occurred in their diet. Red pandas seemed to select most nutritious food items
to feed on. The home range of red pandas averaged 2.2 km2 across individuals (2.6 km2 for the males and 1.7 km2 for the females), and overlapped extensively (ranging 18.9–78.1%). No significant difference was found in monthly percentage
of total home range used among seasons and sexes. The daily movement distance was 455 m (447 m for the females and 463 m for
the males), significantly affected by sexes and months. Our findings indicated that food resource significantly influenced
behaviour of red pandas in foraging and space use, and their behavioural responses are adaptive being helpful to energy intake
and maintenance. 相似文献
15.
Carbon and nutrient dynamics in relation to growth rhythm in the giant bamboo Phyllostachys pubescens 总被引:2,自引:0,他引:2
The carbon and nutrient dynamics in relation to growth rhythm in the giant bamboo Phyllostachys pubescens on Mount Jinyun, Chongqing, China, was studied during 1993–1996. Concentrations of TNC (total non-structural carbohydrates), N, P, and K all showed the same distribution pattern among organs: leaves > branches rhizomes stems roots. The rapid spring growth of new shoots noticeably reduced the concentration of TNC in the rhizomes, in which a large amount of carbohydrates was stored. The N concentration of the rhizomes did not decrease, however. Nutrient concentration of new (1st-year) leaves was significantly higher than that of old (2nd-year) leaves. Although the density of adult shoots was almost the same during 1994–1996, the low ratio of the number of adult shoots with new to that with old leaves from June 1994 to April 1995 resulted in a low TNC concentration in the rhizomes in early spring (April) 1995. This led to a low production of new shoots in the spring of 1995, their number being only ca. 10% of that in 1994 and 1996. Before old leaves were shed, a large amount of nutrients was remobilized and translocated to other plant parts to support further growth. Fertilization with NPK significantly increased the concentrations of N and P in leaves and subsequently increased the number of emerging new shoots. 相似文献
16.
秦岭大熊猫冬春季节对巴山木竹竹林生长指标的选择 总被引:1,自引:0,他引:1
2004~2005年冬季的12月、1月和春季的4月、5月,在秦岭山系南坡佛坪自然保护区内就大熊猫对构成其主要栖息地和食物来源的巴山木竹竹林的选择进行研究后的结果表明:在冬季,大熊猫栖息地多为幼竹与死竹比例基本持平、密度稳定的巴山木竹竹林,主要取食老竹;在春季,大熊猫更偏好选择竹子密度和盖度略低、竹子粗壮高大、幼竹与竹笋比例高的竹林活动,主要取食幼竹。大熊猫春季栖息地幼竹比例通常高过死竹比例,竹林密度处于增长期。竹林进入发笋期后,稀疏、高大的竹林下的粗大竹笋成为大熊猫的主要食物来源。 相似文献
17.
Rachel L. Hansen Meghan M. Carr Carolyn J. Apanavicius Pingping Jiang Heidi A. Bissell Barbara L. Gocinski Frances Maury Marian Himmelreich Sara Beard John R. Ouellette Andy J. Kouba 《Zoo biology》2010,29(4):470-483
The giant panda (Ailuropoda melanoleuca) is classified as a carnivore, yet subsists on a diet comprised almost exclusively of bamboo. Wild and captive giant pandas use highly selective foraging behaviors for processing and consuming bamboo. These behaviors are for the first time quantified in captive giant pandas over a 5‐year period of time showing highly specific seasonal trends. Giant panda feeding behavior was recorded using live video observations of two giant pandas housed at the Memphis Zoo from November 2003 to June 2008. Leaf was the primary plant part consumed from June to December, whereas culm was consumed primarily from February to May, with both bears displaying similar seasonal shifts in plant part consumption. From May to June, leaf consumption increased significantly (P‐values<0.001); from June to August, leaf consumption remained high and stable. From December to March, leaf consumption decreased significantly (P‐values<0.001). Specific behaviors for bamboo leaf and culm consumption were also observed. Both bears formed wads of leaves before ingestion while feeding on leaf, but the male employed this feeding behavior more often than the female (54 and 33%, respectively). Both bears used similar culm‐stripping behavior (26 and 25%), used to remove the outer layer and isolate the pith for consumption. This study indicates that unique seasonal foraging behaviors observed in wild pandas are also apparent in captive animals in relation to plant part selectivity and feeding behaviors. Zoo Biol 29:470–483, 2010. © 2009 Wiley‐Liss, Inc. 相似文献
18.
Changes in the size and age structure of the canopy of the leguminous shrub Retama sphaerocarpa in semi-arid south-eastern Spain were investigated by monitoring growth and survivorship of cladodes (photosynthetic stems) on marked shoots over a period of 26 months. Three basic morphological types of cladodes – long shoots, short shoots, and secondary short shoots – were distinguished.The canopy of the shrubs contained three annual cohorts of cladodes in spring and summer. The number and size of shoots produced each year was highly variable and was apparently related to the amount of rainfall during the preceding cool season. The spring cohort of 1994 produced only 37% of cladodes compared with 1993. Two cohorts of shoots were actually initiated in spring and late summer of each year, but the second cohort produced only 2–12% of the number of cladodes compared with the spring cohort. The proportions of the different cohorts in the canopy changed rapidly from April to August, but only slowly during the remainder of the year when only two annual cohorts remained after extensive litterfall in late summer. This late summer litterfall caused a substantial reduction in green canopy area (40–50%) which was achieved mainly be shedding of one year old cladodes. The life expectancy of cladodes decreased with increasing order of their morphological type from 850 ± 25 days in long shoots to 563 ± 4 days and 546 ± 9 days in short shoots and second order short shoots, respectively.Flowering and fruiting took place from May to July, almost exclusively on one year old cladodes, and coincided with the maximum development of the canopy. Flowering intensity was high in 1994, when individual shoots supported a mean number of approximately 150 flowers. Shoots produced an average of 12.6 ± 0.6 and 5.3 ± 1.0 fruits per shoot in 1993 and 1994, respectively. Most of the annual fruit crop (80–90%) was shed during litterfall in late summer. A proportion of 10–20% was retained in the canopy for up to 12 months, however, with some fruits persisting for more than 22 months. 相似文献