Picea seedlings show apparent acclimation to drought with increasing altitude in the eastern Himalaya

Abstract

We measured plant structural and physiological responses of two sympatric Picea species, Picea likiangensis (Franchet) E. Pritzel var. balfouriana and Picea asperata Masters var. retroflexa to altitude close to the treeline in the eastern Himalaya. Most measured tree characteristics differed between different altitudes, between different ages, and between shaded and un-shaded treatments. Both P. likiangensis and P. asperata had lower foliage area/stem cross-sectional area ratios, smaller specific leaf areas, higher root mass/foliage area ratios, and less negative d 13 C at 3,900 m than at 3,600 m altitude, and in the un-shaded treatment than in the shaded treatment. The 7-and 9-year-old seedlings also showed lower foliage area/stem cross-sectional area ratios, higher root mass/foliage area ratios and less negative d 13 C than younger seedlings. Shading resulted in an increase of biomass accumulation at all altitudes. A close relationship, independent of altitude, was observed between d 13 C and specific leaf area, suggesting that internal resistance could limit CO 2 diffusion to the site of carboxylation. The results indicate that, in spite of greater water availability, trees at higher altitudes show quite a number of apparent acclimations to drought.

Effect of drought and ABA on growth, photosynthesis and antioxidant system of Cotinus coggygria seedlings under two different light conditions

“…Leaf samples for the carbon isotope (␦ 13 C) analysis were oven-dried for 24 h at 80 • C and homogenized by grinding in a ball mill. Stable carbon isotope abundance in combusted samples was measured with a mass spectrometer (Finnegan MAT Delta-E, Bremen, Germany), as described by Li et al (2004). The overall precision of the ı values was better than 0.1‰, as determined from repeated samples.…”

Long-term acclimation of mesophyll conductance, carbon isotope discrimination and growth in two contrasting Picea asperata populations exposed to drought and enhanced UV-B radiation for three years

“…Samples of 100 mg DW of plant material, oven-dried at 70 • C for 24 h, were homogenized by grinding in a ball mill. The stable carbon isotope abundance in the combusted samples was measured with a mass spectrometer (Finnegan MAT Delta-E) as described by Li et al (2004). The overall precision of the ı-values was better than 0.1‰, as determined from repeated samples.…”

Adaptability to elevated temperature and nitrogen addition is greater in a high-elevation population than in a low-elevation population of Hippophae rhamnoides

“…Changes in the photosynthesis parameters of plants grown under N addition have been reported in Picea seedlings in many previous studies (e.g., Li et al 2004). Some studies have showed that the values of photosynthesis parameters significantly increase in Cryptomeria japonica and hybrid poplar seedlings according to the degree of N deposition, while they decrease when the amount of N exceeds the critical point (Nakaji et al 2001;Cooke et al 2005).…”

“…Thus, drought stress resulted in increased water use efficiency. In addition, many previous observations have showed that d 13 C increases with elevation in conifer leaves (Hultin and Marshall 2000;Li et al 2004). Correlations between d 13 C and various abiotic factors over altitude gradients have been reported, including soil moisture, air temperature, atmospheric CO 2 concentration and evaporative demand (Van de Water et al 2002;Maunoury-Danger et al 2010).…”