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四川红杉-岷江冷杉原始林凋落物K和Na的归还动态

曾欣1,付长坤2,杨佳萍1,朱亮1,吴福忠1,张丽1*   

  1. 1四川农业大学生态林业研究所, 长江上游林业生态工程四川省重点实验室, 高山森林生态系统定位研究站, 成都 611130; 2四川师范大学生命科学学院, 成都 610101)
  • 出版日期:2020-05-10 发布日期:2020-05-10

Dynamics of potassium (K) and sodium (Na) return in litterfall in a Larix mastersiana-Abies faxoniana primary forest.

ZENG Xin1, FU Chang-kun2, YANG Jia-ping1, ZHU Liang1, WU Fu-zhong1, ZHANG Li1*   

  1. (1Provincial Key Laboratory of Ecological Forestry Engineering in the Upper Reaches of Yangtze River, Longterm Research Station of Alpine Forest Ecosystems, Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu 611130, China; 2College of Life Science, Sichuan Normal University, Chengdu 610101, China).
  • Online:2020-05-10 Published:2020-05-10

摘要:

以凋落物为载体的养分归还是生态系统物质循环的主要过程,也是林木生长所需养分的重要来源。相对于其他元素,钾(K)和钠(Na)在调节渗透压方面有着极其重要的作用,且淋溶作用强烈,极易流失,但缺乏必要关注。因此,以海拔3589 m高山峡谷区典型的四川红杉(Larix mastersiana)岷江冷杉(Abies faxoniana)原始林为研究对象,在2015年9月到2016年8月期间调查了不同类型凋落物中K和Na元素在不同时期的归还特征。结果表明:1)凋落物K和Na元素年归还量分别为25.34和4.44 kg·hm-2,表现为:凋落叶>凋落枝>其他凋落物>凋落皮>附生植物>繁殖器官。其中,凋落叶和枝占总凋落物K和Na元素归还的85%以上;2)总凋落物、凋落叶和枝的K、Na元素归还动态呈现“双峰型”,最大值出现在5月和10月;凋落皮和繁殖器官K、Na元素归还动态呈现“单峰型”,最大值出现在5月;3)乔木层树种凋落物的K和Na元素呈现“双峰型”的归还模式,最大值在5月和10月,灌木树种凋落物的K和Na元素呈现“单峰型”归还模式,最大值在9—10月。这些结果说明了高山峡谷区典型针叶林不同类型凋落物元素归还的季节性特征,为进一步认识区域森林物质循环及相关的生态学过程提供了基础数据。
 

关键词: 逆境萌发, 小麦, 种子活力, 酶活性, 基因表达

Abstract: Nutrient return with litters is the main process of ecosystem material cycling and an important source of nutrients for tree growth. Compared with other elements, potassium (K) and sodium (Na) play an extremely important role in regulating osmotic pressure. Both elements are easy to be lost, as their leaching is strong. However, there is a lack of necessary attentions. We investigated the return characteristics of K and Na in different types of litter from September 2015 to August 2016 in a primary dark coniferous forest (3589 m a.s.l.), which was dominated by Larix mastersiana andAbies faxoniana. The results showed that: (1) The amount of annual return of K and Na in litter was 25.34 and 4.44 kg·hm-2, respectively, with the order of different organs: foliar litter>twig litter>miscellaneous>bark litter>epiphytic litter>reproductive organ litter. Among them, foliar litter and twig litter accounted for more than 85% of the total return of K and Na. (2) The return dynamics of K and Na in total litter, foliar litter and twig litter presented “bimodal”patterns, with the maximum values in May and October. The dynamics of K and Na returns in bark litter and reproductive organ litter showed a “unimodal” pattern, with a maximum in May. (3) The K and Na in tree litters showed a “bimodal” return pattern, with the maximum values in May and October. The K and Na returns in shrub litters showed a “unimodal” pattern, with peaks in September to October. These results illustrate the seasonal characteristics of element return in different types of litters in typical coniferous forests in alpine areas, providing basic reference for further understanding regional forest material cycling and related ecological processes.

Key words: stress germination, wheat (Triticum aestivum), seed vigor, enzyme activity, gene expression.