Regrowth dynamics of Calamagrostis epigejos after defoliation as affected by nitrogen availability

Abstract

Young plants of a rhizomatous grass Calamagrostis epigejos (L.) Roth were grown from seed in nutrient solutions containing nitrogen in concentrations 0.1, 1.0, and 10 mM. After six weeks of cultivation the plants were defoliated and changes in growth parameters and in content of storage compounds were measured in the course of regrowth under highly reduced nitrogen availability. Plants grown at higher nitrogen supply before defoliation had higher amount of all types of nitrogen storage compounds (nitrates, free amino acids, soluble proteins), which was beneficial for their regrowth rate, in spite of lower content of storage saccharides. Amino acids and soluble proteins from roots and stubble bases were the most important sources of storage compounds for regrowth of the shoot. Faster growth of plants with higher N content was mediated by greater leaf area expansion and greater number of leaves. In plants with lower contents of N compounds number of green leaves decreased after defoliation significantly and senescing leaves presumably served as N source for other growing organs. Results suggest that internal N reserves can support regrowth of plants after defoliation even under fluctuating external N availability. Faster regrowth of C. epigejos with more reserves was mediated mainly by changes in plant morphogenesis.

Suppressing competitive dominants and community restoration with native parasitic plants using the hemiparasitic Rhinanthus alectorolophus and the dominant grass Calamagrostis epigejos

“…It uses the guerrilla strategy of clonal growth (Rebele & Lehmann ) to spread rapidly in previously unoccupied communities diversity of which is consequently reduced by competitive exclusion of subordinate species (Somodi, Virágh & Podani ; Rebele ). The competitive success of the C. epigejos lies in its ability to store and translocate resources below ground (Rebele & Lehmann ; Kavanová & Gloser ; Gloser, Košvancová & Gloser ) and high nutrient use efficiency (Yuan et al . ).…”

The influence of Calamagrostis epigejos expansion on the species composition and soil properties of mountain mesic meadows

“…There are many publications about the physiology and ecology of Calamagrostis epigejos [13,19,27,28]. However, its expansion mechanism and the dynamics of changes it causes in grassland communities and habitats still remain relatively poorly explained.…”

Carbon and nitrogen reserves in marandu palisade grass subjected to intensities of continuous stocking management

“…The mobilization of reserve compounds may be limited more by N than C stores, since N uptake can be severely reduced or even interrupted for several days after defoliation (Clement et al 1978;Jarvis & MacDuff 1989). According to Gloser et al (2007), N reserves can support re-growth of plants after defoliation even under fluctuating external N availabilities. In contrast, Turner et al (2006b) pointed out that N reserves were found to play a minor role during re-growth of cocksfoot (Dactylis glomerata L.), indicating that the reliance on N as a plant reserve has not been conclusively established.…”

“…Although they are used as substrates in respiration, N reserves are still not as important as carbohydrate reserves in supporting re-growth (White 1973). However, Ourry et al (1988Ourry et al ( , 1989 and Gloser et al (2007) concluded that N compounds are important components interfering with restoration of sward leaf area index (LAI) and growth.…”

“…According to Gloser et al . (2007), N reserves can support re-growth of plants after defoliation even under fluctuating external N availabilities. In contrast, Turner et al .…”