Using Leaf Ecological Stoichiometry to Direct the Management of Ligularia virgaurea on the Northeast Qinghai-Tibetan Plateau

Abstract

Leaf ecological stoichiometry not only reflects the plasticity and adaptability, but also the growth of plants within environments where temperature, precipitation, and soil properties vary across an elevation gradient. Ligularia virgaurea (Maxim.) Mattf. ex Rehder & Kobuski — an invasive poisonous plant — is common in the northeast portion of China’s Qinghai-Tibetan Plateau and its presence greatly affects the native ecosystem. Based on L. virgaurea leaf carbon ([C]leaf), nitrogen ([N]leaf) and phosphorus ([P]leaf) concentrations, and their ratios, the species’ coping strategies across an elevation gradient (2,600 m, 3,000 m, and 3,300 m) were identified, and served to inform the development of improved management strategies. Mean [C]leaf, [N]leaf and [P]leaf in L. virgaurea across all elevations were 413.14 g·kg−1, 22.76 g·kg−1, and 1.34 g·kg−1, respectively, while [C]leaf: [N]leaf, [C]leaf: [P]leaf, and [N]leaf: [P]leaf were 18.27, 328.76, and 17.93. With an increase in precipitation and decrease in temperature from 2,600 m to 3,000 m–3,300 m, [C]leaf, [C]leaf: [N]leaf and [C]leaf: [P]leaf of L. virgaurea decreased at first and then increased. The [N]leaf and [P]leaf gradually increased, whereas [N]leaf: [P]leaf showed little change. Although temperature, precipitation and soil water content were the main factors affecting the ecological stoichiometry of L. virgaurea leaves, their roles in influencing leaf elements were different. The [C]leaf was mainly influenced by soil water content, [N]leaf by temperature and soil water content, and [P]leaf by all of them. With potential future climate change in the study area, L. virgaurea may grow faster than at present, although soil P may still be a growth-limiting element. As L. virgaurea can reduce plant diversity and the quality of forage, while increasing biomass, management of L. virgaurea should receive greater attention.

Response of leaf stoichiometry of Potentilla anserina to elevation in China's Qilian Mountains

“…Therefore, [C] leaf /[N] leaf of P. anserina decreased at higher elevations to benefit growth priority. The [N] leaf /[P] leaf of P. anserina increased with elevation, similar to the study of Cao et al (2020) on Oxytropis ochrocephala and the study of Wang et al (2019) on Sabina przewalskii in the Qilian Mountains, while Su et al (2022) found no significant changes in Ligularia virgaurea's [N] leaf /[P] leaf across elevation in the Qilian Mountains. The increasing [N] leaf /[P] leaf of P. anserina with elevation indicates that the growth of P. anserina in the study area may be more susceptible to P-limitation at higher elevations.…”

“…Soil pH exerted a positive influence on [C] leaf , consistent with the study of Liu M. et al ( 2021 ). However, most previous studies showed that higher soil pH had a significant negative impact on [C] leaf as it inhibits photosynthesis (e.g., He et al, 2016 ; Gong et al, 2018 ; Lin et al, 2022 ; Su et al, 2022 ). These results indicated that the impact of soil pH on [C] leaf was significant but varied with species.…”

“…This agrees with the observations of van de Weg et al ( 2009 ) and Hu et al ( 2020 ) and supports our hypothesis that elevation would significantly influence leaf stoichiometry of P. anserina . However, Qin et al ( 2022 ) found that elevation only significantly affected [C] leaf , [N] leaf , and [C] leaf /[N] leaf of Potentilla fruticosa , while Su et al ( 2022 ) reported that elevation was the key factor regulating the leaf stoichiometries of Ligularia virgaurea except [P] leaf and [N] leaf /[P] leaf in the Qilian Mountains. This suggests diverse adaptation strategies of different species to environmental changes.…”

“…Decreased soil pH could promote the reabsorption of nitrogen to maintain plant growth, leading to increased [N] leaf (Su et al, 2022 ). Haynes ( 1986 ) found that when SOC/STN was ≤ 25, soil nitrogen was mineralized as available nitrogen for plant growth, while when it was > 25, microorganisms mineralized soil nitrogen for maintaining their own growth.…”

Arbuscular Mycorrhizal Fungi Improve the Growth, Water Status, and Nutrient Uptake of Cinnamomum migao and the Soil Nutrient Stoichiometry under Drought Stress and Recovery

“…The crushed and sieved (0.2 mm) dried samples were digested via the H 2 SO 4 -H 2 O 2 method in a digesting block at 350 °C [ 47 ] before total N and total P measurements. The total concentration of nitrogen (TN) in the plants was measured by the indophenol blue colorimetry method and assayed at 625 nm; similarly, the total concentration of phosphorus (TP) in plants was measured by the vanadium molybdate yellow colorimetric method at 450 nm [ 48 , 49 ].…”