Schmitt J L, Windisch P G
Programa de Pós-Graduação em Qualidade Ambiental, Laboratório de Botânica, Universidade Feevale, Novo Hamburgo, RS, Brazil.
Braz J Biol. 2012 May;72(2):397-405. doi: 10.1590/s1519-69842012000200023.
The leaf production and senescence, formation and release of spores of Cyathea atrovirens (Langsd. & Fisch.) Domin were analysed based on the monthly monitoring of 50 plants growing in a secondary forest, in the municipality of Novo Hamburgo, in the state of Rio Grande do Sul, during the year 2004. The caudex height and number of mature and fertile leaves were recorded annually in 2004-09. In 2004, monthly production and senescence of leaves were concomitant, without total leaf abscission. Population synchrony at emergence (Z = 0.86) and leaf senescence (Z = 0.82) increased in spring but did not correlate with temperature and photoperiod. All individuals were fertile and the sporangia production and spore liberation presented higher and equal synchrony (Z = 0.84) respectively in spring and summer. Sporangia production was related with temperature and photoperiod, however taller plants did not produce more fertile leaves. Phenological events analysed were not influenced by precipitation, as expected for forests in non-seasonal climate. Over five years (2004-09), the annual mean caudex growth varied between 1.19 and 2.50 cm.year-1 and the plants appeared to have an ability to maintain a relatively stable amount of leaves throughout this period.
基于对南里奥格兰德州新汉堡市一片次生林中生长的50株植物在2004年全年的月度监测，分析了黑桫椤（Cyathea atrovirens (Langsd. & Fisch.) Domin）的叶片产生与衰老、孢子的形成与释放。在2004年至2009年期间，每年记录茎干高度以及成熟叶和可育叶的数量。2004年，叶片的月度产生与衰老同时发生，没有出现全部落叶的情况。出芽时（Z = 0.86）和叶片衰老时（Z = 0.82）的种群同步性在春季增加，但与温度和光周期无关。所有个体均可育，孢子囊的产生和孢子释放分别在春季和夏季呈现出更高且相等的同步性（Z = 0.84）。孢子囊的产生与温度和光周期有关，然而较高的植株并没有产生更多的可育叶。所分析的物候事件不受降水影响，这与非季节性气候森林的预期情况一致。在五年（2004年至2009年）期间，茎干的年均生长量在1.19至2.50厘米·年-1之间变化，并且在此期间植株似乎有能力维持相对稳定的叶片数量。
