Ecological Indicators (Sep 2021)
The relationship of the main root-shoot morphological characteristics and biomass allocation of Saussurea salsa under different habitat conditions in Sugan lake wetland on the northern margin of the Qinghai-Tibet Plateau
Abstract
The response analysis of plant morphological characteristics and biomass allocation in salt marsh wetland to heterogeneous habitats is helpful to explore the internal correlation between plant morphological plasticity mechanism and biomass allocation, which is of great significance for the in-depth understanding of habitat stress tolerance strategies of salt marsh plants. However, the relationship between the main root-shoot morphological indexes and biomass allocation of inland alpine arid area salt marsh plant is still unclear. According to the difference of the habitat conditions of Saussurea salsa, 3 test sample were set up, plot I (the Inland salt marsh area, 200–500 m from the lakeshore), plot II (the Oasis Wetland area, 500–1000 m from the lakeshore), plot III (the Seasonal river wetland area, 1000–1500 m from the lakeshore). The relationship between the main root-shoot morphological characteristics and biomass allocation of Saussurea salsa in the Sugan Lake salt marsh was studied in response to heterogeneous habitats. The results showed that Saussurea salsa tended to form the large and thick leaf pattern, the root morphological construction pattern with moderate root diameter (RD) and specific root length (SRL), and the root-shoot ratio (RSR) with minimum biomass allocation strategy in plot I. In plot II, the thin-leaf pattern with the largest specific leaf area (SLA) and the smallest thickness (LT) was formed. Meanwhile, the slender root morphology pattern with the smallest RD, the largest SRL and the moderate RSR was preferred. In plot III, a lobular pattern with minimum leaf area (LA) and SLA, and moderate thickness was formed. At the same time, a thick root pattern with maximum RD and minimum root length, and a maximum RSR were formed. Moreover, there was a highly significant negative correlation (p < 0.01) between SLA and RD at three plots. Besides, there appeared a less significant positive correlation (p < 0.05) between LA and LT, shoot biomass at three plots. Through the synergistic changes of morphological characteristics of aboveground and underground organs and biomass allocation strategies, the inland salt marsh plant population can maintain normal survival, growth and reproduction under harsh environment, which reflects its morphological plasticity and stress resistance mechanism under heterogeneous environment.
