The patterns of N/P/K stoichiometry in the Quercus wutaishanica community among different life forms and organs and their responses to environmental factors in northern China

Abstract

Nitrogen (N), phosphorus (P), and potassium (K) play an essential role in plant growth, development and reproduction. The pattern of nutrient stoichiometry across various plant organs and plant life forms can reflect the trade-off of plant growth strategies. However, there is a lack of systematic research on plant nutrient stoichiometry and the influence of environmental factors. Therefore, the main forest type Quercus wutaishanica community was considered as the object for this study and samples of different life forms (trees, shrubs, herbs) and different organs (leaves, stems, roots, seeds) were collected in northern China. First, we analyzed N/P/K stoichiometry among different organs and different life forms in the Quercus wutaishanica natural community. Second, we explored the influence of environmental factors on N/P/K stoichiometry and clarified the relative contributions of variables among different life forms. The results showed that the distributions of nutrient stoichiometry in different life forms and organs were different. As the most active organ, the content of elements in leaves was significantly higher than that in other organs. Among them, P was the main limitation in leaves and roots; N was the main limitation in stems and seeds in this area. Environmental factors had different effects on the N/P/K stoichiometry of different life forms. The nutrient stoichiometry in trees was mainly affected by topographical factors; the nutrient stoichiometry in shrubs and herbs was mainly affected by soil factors. Therefore, the differences in N, P, and K stoichiometry may be caused by the growth environment and the plant’s own adaptation strategies. All of these studies provide new insight for studying the homeostasis system within plants and communities by means of stoichiometry. This study is expected to guide the management and protection of the natural community, make the natural community give more ecological functions, and provide support for the cultivation of artificial forests in the future.