Variations in Species-Level N:P Stoichiometry of Charophytes and Aquatic Angiosperms on the Tibetan Plateau

Abstract

The variations in nitrogen (N) and phosphorus (P) stoichiometry between species and along environmental gradients reflects plant growth and survival under certain conditions. Exploring the determinants of plant N and P stoichiometry at species level could help us understand the mechanisms of plant distribution. Temperature is considered a driving factor in forming the geographical patterns of plant N and P stoichiometry at the community level. Here we selected four common aquatic plants to explore the divergence of plant N and P stoichiometry between species and the species-level variations across large geographical gradients on the Tibetan Plateau. We found that plant N and P concentrations and N:P ratios were significantly different among the four species/groups. Charophytes had the lowest N and P concentrations, but the N:P ratio did not differ significantly from those of angiosperms. All four species/groups plant N concentrations were positively correlated with P concentrations. The temperature was also the primary explanatory variable, while the habitats properties showed weak and inconsistent effects on plant N and P stoichiometry. Plant N and P concentrations increased, but N:P ratios decreased, with decreasing temperature. Altitude, rather than latitude, determined the environmental patterns of plant N and P stoichiometry by affecting the temperature. These findings indicated that, after removing the influences of species replacement at the community level, temperature still plays a primary role in forming the geographical patterns of plant N and P stoichiometry at species level. Plants of each species could optimize their investment strategies of elements under different environmental conditions. The Tibetan Plateau is recognized as an area that is sensitive to global warming. Our results provided evidence, in terms of N and P stoichiometry, of potential variations among aquatic plants in nutrient absorption and element cycling under climatic warming.

Salinity Induces Allometric Accumulation of Sulfur in Plants and Decouples Plant Nitrogen‐Sulfur Correlation in Alpine and Arid Wetlands

“…Yang et al, 2021). Previous studies on the Tibetan Plateau indicated that LN of wetland plants increased with decreasing temperature (Wang, 2001(Wang, , 2018. In this study, similar patterns were detected for all observations when the study area was expanded to the Arid Regions and the whole western alpine and arid regions of China (Figure S4 in Supporting Information S1), confirming the importance of low temperature for N accumulation in plants (Reich & Oleksyn, 2004).…”

“…Environmental patterns of LN have been well studied in both terrestrial and aquatic plants at global (Reich & Oleksyn, 2004), national (Han et al., 2011) and regional scales (Xia et al., 2014; Zhao et al., 2016), and were compared among plant life forms (Pan et al., 2020; L. Yang et al., 2021). Previous studies on the Tibetan Plateau indicated that LN of wetland plants increased with decreasing temperature (Wang, 2001, 2018). In this study, similar patterns were detected for all observations when the study area was expanded to the Arid Regions and the whole western alpine and arid regions of China (Figure S4 in Supporting Information S1), confirming the importance of low temperature for N accumulation in plants (Reich & Oleksyn, 2004).…”

Macrophyte habitat architecture and benthic-pelagic coupling: Photic habitat demand to build up large P storage capacity and bio-surface by underwater vegetation

“…Both the phosphorus content and the nutrient elemental stoichiometry of the aquatic plants vary among plant species or locations (e.g., Lukatelich et al, 1987;Mazej and Germ, 2008;Wang et al, 2018). Despite this rather narrow range of variation for phosphorus acquisition among plant species, the essential role of macrophytes for lake ecosystems lies in their phosphorus storage capacity, which means retaining this nutrient element and thus making a large amount of phosphorus not bio-available for the development of photosynthetic plankton microorganisms during the growing season of a current year.…”

Soil Degradation Effects on Plant Diversity and Nutrient in Tussock Meadow Wetlands

“…Most previous studies pay close attentions to the exchange of nutrient and energy between plants and the environment at regional and local scales (Choudhury et al 2018). Plant nutrient reflects the ability of carbon accumulation in plants as well as indicating the effect limited nutrient availability has on the plant growth during growing season (Zhang et al 2018;Wang et al 2018b). Thus, plant nutrient has been applied to resolve ecological problems, especially in relation to the growth and responses of plants to soil nutrients.…”