沙埋对中国浑善达克沙地榆树幼苗存活、生长、气体交换及生物量分配的影响

Effects of sand burial on survival, growth, gas exchange and biomass allocation of Ulmus pumila seedlings in the Hunshandak Sandland, China.

作者信息

Shi L, Zhang Z J, Zhang C Y, Zhang J Z

机构信息

Institute of Botany, the Chinese Academy of Sciences, Nanxincun 20, Beijing 100093.

出版信息

Ann Bot. 2004 Oct;94(4):553-60. doi: 10.1093/aob/mch174. Epub 2004 Aug 25.

DOI:10.1093/aob/mch174

PMID:15329332

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4242228/

Abstract

BACKGROUND AND AIMS

In the last decade, the number of young plants of Ulmus pumila in the Hunshandak Sandland has decreased sharply because of severe sand burial, and their ecological protective function has been weakened. In order to develop an understanding of the tolerance of U. pumila to sand burial and to suggest reasonable measures to protect the sparse-elm-grassland ecosystem, the effects of burial on the survival, growth, photosynthesis and biomass allocation in U. pumila were studied.

METHODS

Seedlings were buried at five different depths in pot experiments: no burial (control), partial burial (33 % and 67 % stem height), and complete burial (100 % and 133 % stem height). Growth analyses and measurements of photosynthesis were carried after the plants had been uncovered.

KEY RESULTS

All the plants survived partial burial, but about 30 % and 80 % of the seedlings died as a result of the 100 % and 133 % sand burial treatments, respectively. The numbers of newly produced leaves and branches, and the height of the stems of the seedlings in the 33 % and 67 % burial treatments during the period of the experiment were significantly greater than those in the control. Furthermore, net photosynthetic rate, transpiration rate and water use efficiency were also elevated by the partial burial, but not affected by burial time. This might be attributed to the increased root length, which improved water acquisition. The biomass and biomass allocation of the seedlings were significantly changed by the burial treatments and burial times. The biomass was enhanced by partial burial but was reduced by complete burial at each burial time. However, the biomass allocation was not significantly changed by the 33 % and 67 % sand burial treatments 2 or 4 weeks following the burial.

CONCLUSIONS

Ulmus pumila was shown to be tolerant to partial sand burial, but must be protected from complete burial.

摘要

背景与目的

在过去十年间，由于严重的沙埋，浑善达克沙地的榆树幼树数量急剧减少，其生态保护功能也被削弱。为了解榆树对沙埋的耐受性，并提出保护疏林草原生态系统的合理措施，研究了沙埋对榆树存活、生长、光合作用及生物量分配的影响。

方法

通过盆栽试验，将幼苗埋于五个不同深度：不埋（对照）、部分埋（茎高的33%和67%）和完全埋（茎高的100%和133%）。植株出土后进行生长分析和光合作用测定。

主要结果

所有植株在部分埋处理下均存活，但在100%和133%沙埋处理下，分别约有30%和80%的幼苗死亡。在试验期间，33%和67%埋深处理的幼苗新叶和新枝数量以及茎高显著高于对照。此外，部分埋处理提高了净光合速率、蒸腾速率和水分利用效率，但不受埋深时间影响。这可能归因于根长增加，从而改善了水分获取。埋深处理和埋深时间显著改变了幼苗的生物量和生物量分配。部分埋处理增加了生物量，而在每个埋深时间下，完全埋处理均降低了生物量。然而，在埋深2周或4周后，33%和67%沙埋处理对生物量分配没有显著影响。