%0 Journal Article %A Bin-Yang LIU %A Wei-Qiu LIU %A Yi-Shun ZHANG %A Chun-Yi LEI %T Physiological responses of bryophytes experienced low temperature stress to simulated nitrogen deposition %D 2011 %R 10.3724/SP.J.1258.2011.00268 %J Chinese Journal of Plant Ecology %P 268-274 %V 35 %N 3 %X

Aims Increasing N deposition and frequent abnormal weather are two characteristics of global climate change. Our objective was to study the physiological responses of bryophytes to simulated nitrogen treatments and low temperature stress to provide insights to the relationship between N deposition and compensatory effect after low temperature stress.
Methods Physiological responses of three bryophyte species, Pogonatum cirratum subsp. fuscatum, Hypnum plumaeforme and Reboulia hemisphaerica, which were subjected to a 2-year-simulated N deposition and suffered a low temperature stress in early 2008, were studied and compared with the results of the bryophytes that experienced a 1-year-simulated N deposition and normal weather conditions. N treatments (Control, 20, 40 and 60 kg N·hm-2·a-1) in three replicates were established for each species. The N additions were divided into four applications per year.
Important findings The results of 2008 showed that net photosynthetic rate and concentration of starch decreased with increasing N addition doses within the range of 0-60 kg N·hm-2·a-1. The concentration of total N increased with increasing N treatment doses within the range of 0-40 kg N·hm-2·a-1, but decreased at N addition doses of 60 kg N·hm-2·a-1. At control and low N addition conditions (20 kg N·hm-2·a-1), most of the indices of carbon and nitrogen metabolism of the three bryophytes were higher than the results of 2007 of the same species at the same N treatments, but N addition depressed the increase. At high N treatment conditions (≥ 40 kg N·hm-2·a-1), the results of 2007 and 2008 were usually similar. Results indicate that the bryophytes exhibit overcompensatory growth after experiencing a low temperature stress, but at stimulated N deposition conditions, their compensatory ability decreases.

%U https://www.plant-ecology.com/EN/10.3724/SP.J.1258.2011.00268