Characteristics of Water Physiological Integration and its Ecological Significance for Populus euphratica Young Ramets in an Extremely Drought Environment

Abstract

Water physiological integration plays an important role and has profound effects on the population renewal and expansion of clonal plants. This work discussed the spatial distribution architecture, water sources, water physiological integration, and the ecological significance of Populus euphratica young ramets in an extremely drought environment based on field investigation, stable isotope technology, and eco‐physiological experiments. The spatial distribution architecture of P. euphratica young ramets assumes a guerrilla growth form that is adapted to significant heterogeneity and patches of habitat resources. There is obvious water integration that is characterized by an acropetally flow. The water integration process and daily flow showed the bimodal pattern following the physiological rhythm of parent trees and declined with increasing length of spacers connecting parent trees and their young daughter ramets. The young daughter ramets of P. euphratica can use the deeper soil water in a similar manner to the parent trees and obtain an average daily water acquisition of about 1.09 kg by water integration when the spacer length is about 2–3 m. It is about 5 times as much water as seedlings sucking by themselves. This lets young ramets maintain higher leaf water content and midday leaf water potential of 10.27% and 29.73%, respectively, than seedlings in same habitats. Therefore, P. euphratica young ramets can benefit from a higher survival advantage in extreme drought habitats compared to seedlings. This facilitates the establishment and growth of young ramets in those adverse habitats where P. euphratica seedlings are less likely to survive.

Influence of the size of clonal fragment on the nitrogen turnover processes in a bamboo ecosystem

“…All clonal fragments must adopt a cost-benefit tradeoff strategy when the costs outweigh the benefits of resource translocation (Wang et al, 2014;Zhang et al, 2020). Results showed that this cost-benefit tradeoff strategy occurred when the spacer length was approximately 30 cm (Figure 3), which was different from the results for Populus euphratica (20-30 m) (Zhu et al, 2018), Halophila stipulacea (2.7 cm), and Cymodocea nodosa (81 cm) (Marba et al, 2002). This may be due to differences in species of clonal plants (D'Hertefeldt et al, 2014;You et al, 2014).…”

“…Differences in spacer length may affect the energy required for resource translocation and limit the intensity of clonal integration (Liu et al, 2004;Li et al, 2008;Yu et al, 2020). Previous studies have shown that the benefits of the physiological integration of water in a clonal fragment of Indocalamus decorus and Populus euphratica decrease when the spacer length increases (Hu et al, 2015;Zhu et al, 2018). In addition, the ramet number can also lead to differences in the sizes of clonal fragments.…”

“…Numerous previous studies have indicated that fragment size can strongly affect the survival, regrowth, and biomass of clonal ramets based on the tradeoff between costs and benefits (Dong et al, 2012;Lin et al, 2012;Huber et al, 2014). Several studies have tried to reveal the influence of the size of clonal fragments on water integration (Hu et al, 2015;Zhu et al, 2018). However, the effect of differences in the sizes of clonal fragments on rhizosphere processes, such as nitrogen turnover, remains largely unknown.…”

Introduction to the Water‐Soil‐Air‐Plant‐Human Nexus: Modeling and Observing Complex Land Surface Systems at River Basin Scale

“…It was found that the increased precipitation brought an enhanced carbon sequestration for the desert-grassland ecosystem in Inner Mongolia (Zhang et al, 2019). The characteristics of water physiological integration to young ramets of Populus euphratica Oliv., which is important in maintaining oases in the desert riparian forest ecosystem, was found to be characterized by an acropetally flow by combining field survey and experiment (Zhu et al, 2018). Finally, the relationships between the flooding of 413 Australian catchments and larger-scale climate indices such as the El Niño-Southern Oscillation were investigated (Liu, Zhang, et al, 2018).…”

Belowground inter‐ramet water transport capacity in Populus euphratica, a Central Asian desert phreatophyte

“…As established P. euphratica trees are completely dependent on groundwater and as this species is capable of forming extensive clones, the question of the water transport capacity through the spacers that connect a ramet with its 'parent' plant arises. Recently, Zhu et al (2018) conducted on-site measurements of the water flow through P. euphratica spacers, but only considered the connections between small 'daughter ramets' (<1.5 m high, <3.0 cm stem diameter) with their 'parent' plant and did not include mature tree ramets in their study. Nevertheless, they found a significantly higher water use in the ramets compared to that of seedlings.…”