Family, visitors and the weather: patterns of flowering in tropical rain forests of northern Australia

Abstract

Summary1 A data base on the flowering phenology of the Wet Tropics bioregion of far northern Queensland, Australia, has been constructed, based upon over 36 774 records from two Queensland-based herbaria. 2 Flowering patterns have been analysed against the predictions of three overlapping hypotheses based on climatic, biotic and phylogenetic explanations. No one hypothesis is supported to the exclusion of the others. 3 Patterns of flowering in the Wet Tropics show marked seasonal increases and decreases, except in the northern lowlands. In general this seasonality correlates with rainfall and temperature and is exacerbated by increasing latitude and altitude. 4 There is little or no statistical evidence for the over-dispersion of flowering times that would indicate a competition-avoidance mechanism: flowering within taxa or morphological groups tends to be clumped (and if not, is random). 5 That clumping of flowering within taxa does not coincide with a single season provides support for a mass action hypothesis based on the minimization of generalist predation and/or the avoidance of flower predation. 6 Timing of flowering did show some consistency among species within genera and within families, but there was little consistency at higher taxonomic levels. Clear separation of the biotic and phylogenetic hypotheses requires greater knowledge of pollination ecology and phylogeny of this large and diverse flora. 7 Understanding of flowering patterns and their underlying determining mechanisms is a key to assessing the ecosystem health of the forest. Our results highlight the importance of competitive interactions and of physical and evolutionary factors as determinants of flowering time, intensity and co-occurrence in tropical forests.

Phenophysiological variation of a bee that regulates hive humidity, but not hive temperature

“…Rather, they had a higher asymptotic VĊ O2 (y 0 ) in the wet summer than in the dry winter. Hence, acclimatisation may be acting to match metabolic rates with ecological energy availability in the wet summer, which is the peak season for flowering and nectar production in tropical Australia (Boulter et al, 2006). High metabolic rate is correlated with the maintenance of highly active flight muscles (Suarez, 2000;Suarez et al, 1996), and higher activity.…”

Reproductive phenology of Miconia mirabilis (Melastomataceae) within three distinct physiognomies of Atlantic Forest, Bahia, Brazil

“…The presence of these abundant resources throughout the year clearly influenced the general pattern of the community. Continuous and extended reproductive patterns mean year-round food availability for pollinators and frugivores, and this in turn contributes to community maintenance through the constant presence of the animals using those resources (Snow 1965, Denslow et al 1986, Pedroni et al 2002, Bolmgren et al 2003, Boulter et al 2006, Elzinga et al 2007.…”

Some growth characteristics and relative competitive ability of invasive Spartina alterniflora and native Scirpus mariqueter

“…(1)气候因素假说: 气候因素假说认为, 植物开 花物候与环境因素的变化有关, 这些环境因子主要 包括日照长度 (Stevenson et al, 2008)、温度 (Ashton et al, 1988)、降水 (Borchert, 1996)和太阳辐射强度 (Wright & van Schaik, 1994 (Kochmer & Handel, 1986;Bolmgren et al, 2003;Chang-Yang, et al, 2013;Du et al, 2015)。但也有研究表明, 植物 开花物候受系统发育关系的影响较小, 并未表现出 明显的谱系保守性 (Frankie et al, 1974;Boyle & Bronstein, 2012)。系统发育关系是否对所有森林植 物的开花物候都有影响仍然需要进一步研究, 而且 之前的相关研究多集中在比较高的分类学等级如 科或属的水平上 (Kochmer & Handel, 1986;Wright & Calderón 1995;Boulter et al, 2006) (Petersen et al, 2010;Jia et al, 2011) (Jones, 1978;Kevan, 1978) (Staggemeier et al, 2010;Chang-Yang et al, Wright & Calderón, 1995;Boulter et al, 2006;Staggemeier et al, 2010) Blomberg K值法 (Blomberg et al, 2003), 基于循环 统计校正K值, 计算循环数据的谱系信号K值 (Du et al, 2015), 即利用开花时间之间的循环距离而不是 线性绝对距离进行分析。 (Westoby et al, 1995), 因此近缘种倾向于同一时间开花以利于 吸引传粉者 (Boulter et al, 2006); 第二, 近缘种因为 拥有相似的遗传基础而使其进化方向受到限制, 从 而更容易产生相近的开花时间 (Gould & Lewontin, 1979;Kochmer & Handel, 1986;Johnson, 1993 …”