Non-Structural Carbohydrate Storage Strategy Explains the Spatial Distribution of Treeline Species

Abstract

Environmental factors that drive carbon storage are often used as an explanation for alpine treeline formation. However, different tree species respond differently to environmental changes, which challenges our understanding of treeline formation and shifts. Therefore, we selected Picea jezoensis and Betula ermanii, the two treeline species naturally occurring in Changbai Mountain in China, and measured the concentration of non-structural carbohydrates (NSC), soluble sugars and starch in one-year-old leaves, shoots, stems and fine roots at different elevations. We found that compared with P. jezoensis, the NSC and soluble sugars concentrations of leaves and shoots of B. ermanii were higher than those of P. jezoensis, while the starch concentration of all the tissues were lower. Moreover, the concentration of NSC, soluble sugars and starch in the leaves of B. ermanii decreased with elevation. In addition, the starch concentration of B. ermanii shoots, stems and fine roots remained at a high level regardless of whether the soluble sugars concentration decreased. Whereas the concentrations of soluble sugars and starch in one-year-old leaves, shoots and stems of P. jezoensis responded similarly changes with elevation. These findings demonstrate that compared with P. jezoensis, B. ermanii has a higher soluble sugars/starch ratio, and its shoots, stems and fine roots actively store NSC to adapt to the harsh environment, which is one of the reasons that B. ermanii can be distributed at higher altitudes.

Changes in Growth Parameters, C:N:P Stoichiometry and Non-Structural Carbohydrate Contents of Zanthoxylum armatum Seedling in Response to Five Soil Types

“…NSC, which mainly includes glucose, fructose, sucrose, and starch, are products of plant photosynthesis, and its levels in plant organs can reflect the correction of C uptake. Moreover, NSC levels are also necessary for transport metabolism and osmotic regulation, which can be used to resist adverse external environments in plants [22,27]. Soil, as one of the environmental factors, will affect the normal physiological metabolism of trees and then change the storage of carbohydrates in trees and their distribution in various organs [27].…”

“…Moreover, NSC levels are also necessary for transport metabolism and osmotic regulation, which can be used to resist adverse external environments in plants [22,27]. Soil, as one of the environmental factors, will affect the normal physiological metabolism of trees and then change the storage of carbohydrates in trees and their distribution in various organs [27]. Therefore, NSC can be used as one of the indexes to evaluate whether a certain soil is suitable for the cultivation of Z. armatum [49].…”

“…In plant organs, the quantity of NSCs commonly reflects C supply as well as the balance between C acquisition and consumption [25]. Higher NSC concentrations can improve the drought resistance and cold stress resistance of plants, which is beneficial for the survival and growth of plants in adverse environments [26,27]. Plants may adjust their biomass, nutrient content distribution, and photosynthetic characteristics to meet their own growth and development needs in response to different soil environments, which is an adaptation strategy to variable environments [21,28].…”

Combined Application of Nitrogen and Phosphorus Promotes the Growth and Nutrient Accumulations of Cinnamomum camphora Container Seedlings

“…Soluble sugar and starch are nutrient compositions stored in plant tissues that reflect the nutrient status of the plant. It can also provide energy and metabolic intermediates for plant growth [31,32]. Soluble proteins are important osmoregulatory substances that play a protective role in vital cellular substances and biological membranes [33].…”

Spatial and Temporal Patterns of Non-Structural Carbohydrates in Faxon Fir (Abies fargesii var. faxoniana), Subalpine Mountains of Southwest China

“…These functions include growth activity, osmoregulation, osmoprotection, pest and disease resistance, water and nutrient transport, storage, and drought and cold resistance [9,[20][21][22][23]. The higher ratio of soluble sugars and starches in plant organs explains the ability of some species to grow in low-temperature stressed environments at high elevations [24].…”