Leaf Nitrogen and Phosphorus Stoichiometry and Its Response to Geographical and Climatic Factors in a Tropical Region: Evidence from Hainan Island

Abstract

Leaf stoichiometry effectively indicates the response and adaptation of plants to environmental changes. Although numerous studies on leaf stoichiometry patterns have focused on the mid-latitudes and specific species of plants, these patterns and the effect of the climate change on them across a broad range of plants have remained poorly characterized in hot and humid regions at low latitudes. In the present study, leaf N, P, N:P, C:N, and C:P ratios, were determined from 345 plant leaf samples of 268 species at four forest sites in Hainan Island, China. For all plants, leaf N (3.80 ± 0.20 mg g−1) and P (1.82 ± 0.07 mg g−1) were negatively correlated with latitude and mean annual temperature (MAT) but were positively correlated with longitude. Leaf N was found to be positively correlated with altitude (ALT), and leaf P was positively correlated with mean annual precipitation (MAP). The leaf C:N ratio (278.77 ± 15.86) was significantly correlated with longitude and ALT, leaf C:P ratio (390.69 ± 15.15) was significantly correlated with all factors except ALT, and leaf N:P ratio (2.25 ± 0.10) was significantly correlated with ALT, MAT, and MAP. Comparable results were observed for woody plants. The results suggest that leaf stoichiometry on Hainan Island is affected by changes in geographical and climatic factors. In addition, the low N:P ratio indicates that plant growth may be limited by N availability. Moreover, the significant correlation between leaf N and P implies a possible synergistic relationship between N and P uptake efficiency in the plants of this region. This study helps to reveal the spatial patterns of leaf stoichiometry and their response to global climate change in a variety of plants in tropical regions with hot and humid environments, which may provide an insight in nutrient management in tropical rainforest.

Response of carbon, nitrogen, and phosphorus in leaves of different life forms to altitude and soil factors in Tianshan wild fruit forest

“…In this study, the carbon-to-nitrogen ratio of arbor leaves was higher than that of herbs. Since the growth rate of arbors was lower than that of herbs, arbors reduced the photosynthetic rate by increasing the carbon content in the leaves to improve their tolerance to high temperatures and drought (Wang J. J. et al, 2023). According to Koerselman and Meuleman (1996), when the nitrogen-to-phosphorus ratio of plant leaves is greater than 16, plant growth is mainly restricted by phosphorus, and when the nitrogen-to-phosphorus ratio is between 14 and 16, plant growth may be limited by both nitrogen and phosphorus; when the nitrogen-phosphorus ratio is less than 14, plant growth is mainly determined by nitrogen.…”

Leaf stoichiometry of potassium, calcium, and magnesium in tropical plants: Responses to climatic and geographical variations—A case study from Hainan Island

“…Global climate change is a complex phenomenon that exerts direct and indirect influences on the physical, biological, and chemical processes within ecosystems (Fahad et al, 2021; Hong et al, 2022). Such changes have the potential to modulate nutrient availability, alter plant physiological functions, and subsequently impact plant stoichiometry (Rosenblatt & Schmitz, 2016; Lin et al, 2023; Wang et al, 2023a). Therefore, it is necessary to conduct a multifaceted and comprehensive analysis of the factors controlling the leaf K, Ca, and Mg contents in plants.…”

“…Such changes have the potential to modulate nutrient availability, alter plant physiological functions, and subsequently impact plant stoichiometry (Rosenblatt & Schmitz, 2016;Lin et al, 2023;Wang et al, 2023a). Therefore, it is necessary to conduct a multifaceted and comprehensive analysis of the factors controlling the leaf K, Ca, and Mg contents in plants.…”