Elevated temperature differently affects growth, photosynthetic capacity, nutrient absorption and leaf ultrastructure of Abies faxoniana and Picea purpurea under intra- and interspecific competition

Abstract

There is a limited understanding of the impacts of global warming on intra- and interspecific plant competition. Resolving this knowledge gap is important for predicting the potential influence of global warming on forests, particularly on high-altitude trees, which are more sensitive to warming. In the present study, effects of intra- and interspecific competition on plant growth and associated physiological, structural and chemical traits were investigated in Abies faxoniana and Picea purpurea seedlings under control (ambient temperature) and elevated temperature (ET, 2 °C above ambient temperature) conditions for 2 years. We found that A. faxoniana and P. purpurea grown under intra- and interspecific competition showed significant differences in dry matter accumulation (DMA), photosynthetic capacity, nutrient absorption, non-structural carbohydrate (NSC) contents and leaf ultrastructure under ET conditions. ET increased leaf, stem and root DMA of both conifers under both competition patterns. Moreover, under ET and interspecific competition, P. purpurea had overall superior competitive capacity characterized by higher organ (leaf, stem and root) and total DMA, height growth rate, net photosynthetic rate, specific leaf area, water use efficiency (δ13C), leaf and root N and NSC concentrations and greater plasticity for absorption of different soil N forms. Thus, the growth of P. purpurea benefitted from the presence of A. faxoniana under ET. Our results demonstrated that ET significantly affects the asymmetric competition patterns in subalpine conifer species. Potential alteration of plant competitive interactions by global warming can influence the composition, structure and functioning of subalpine coniferous forests.

Combined effects of water stress and salinity on growth, physiological, and biochemical traits in two walnut genotypes

“…The same leaves used for gas exchange measurements were sampled and analyzed for the carbon isotopic composition expressed as δ 13 C values (relative to Pee Dee Belemnite). The 13 C/ 12 C ratios of the leaf samples were determined using DELTA V Advantage Isotope Ratio Mass Spectrometer (Thermo Fisher Scientific, Inc.) according to the procedure by Yu et al (2019).…”

Variations in Rainfall Affect the Responses of Foliar Chemical Properties of Cunninghamia lanceolata Seedlings to Soil Warming

“…Tubes with residue were left uncovered and ovendried at 80 • C, incubated in perchloric acid at 80 • C for 20 min, and centrifuged at 21,000 g for 10 min. Glucose equivalents were used to determine soluble sugar and starch concentrations using the anthrone-sulfuric acid method (Yu et al, 2019). Starch and soluble sugar concentrations were added to calculate the total non-structural carbohydrate concentration.…”

Effects of Warming and N Deposition on the Physiological Performances of Leymus secalinus in Alpine Meadow of Qinghai-Tibetan Plateau

“…It can influence carbon sequestration in terrestrial ecosystems, especially alpine ecosystems (Ganjurjav et al, 2018). Warming and drying over the QTP is becoming serious for decades (Chen et al, 2014), which may affect plant physiological processes such as photosynthesis and enzymatic antioxidant (Shi et al, 2010;Yu et al, 2019). Generally, photosynthetic process and the antioxidant enzyme are the most sensitive to climate warming (Atkin et al, 2006).…”