Ecological Significance Of Stable Isotope Carbon And Soil Physical And Chemical Properties Of Tamarix Chinensis In The Lower Reaches Of The Tarim River

Tamarix is a major plant species of the desert ecosystem in the arid region of northwestern China.During the continuous growth of Tamarix,wind and sand will be blocked by Tamarix and form sand-hillocks.In turn,sand-hillocks will promote the growth of Tamarix.After long-term interaction between sand and tamarisk,sand-hillocks will be formed.Tamarix sand-hillocks will be formed in particular because of the sand and tamarisk litter.The hierarchy is known as the"Tamarix sand-hillocks layer."There is abundant environmental information in the layer of the sand-hillocks of the Tamarix.As one of the effective tools for studying environmental changes in the arid regions,the Tamarix sand-hillocks play a very important role in the development of the sand-hillocks.The Tarim River is located in the northern part of the Tarim Basin in Xinjiang and is subject to the dual impact of human economic and social development on large-scale water conservancy.Due to the unreasonable use of water resources,the rivers in the lower reaches of the Tarim River?here in after referred to as Tahe?have dried up for 320km,and the ecological environment in the surrounding areas has been greatly damaged.Three observation sections-Yingsu,Abdallah,and Kardai in the lower reaches of the Tahe River in Xinjiang are selected.Tamarix and its sand-hillocks,which are one of the main groups of the Tahe River,are selected as research objects.Based on the physical forms of Tamarix Scrub and sand-hillock,the stable isotope carbon,cations,ecological stoichiometric characteristics,and sporo-pollen correlation analysis of Tamarix,the combination of meteorological data from Tishigank Weather Station reveals the region Environmental changes in recent years,forecasting future environmental evolution.To provide a theoretical basis and reference materials for understanding the effects of past environmental changes in the region and future environmental evolution on Tamarix stratification.The main findings of this article are as follows:1.Effects of Stable Isotope Carbon of Tamarix on Tamarix Scrub and sand-hillock?1?The maximum number of years for a sample of sphagnum sand-hillocks is 10 years from 2006 to 2015.With the increase of the sand layer of Tamarix,the content of?¹³C of litter in the layer showed a decreasing trend,and there was a negative correlation between?¹³C and carbon content.The average value of?¹³C measured in the study area is-24.42‰,the maximum value is-22.09‰,the minimum value is-25.24‰,and Tamarix is a C₃ plant.?2?With the increase of the layer length of Tamarix,the?¹³C decreased year by year.The height,length,width,and spatial occupancy rate of the long axis,short axis,height,space occupancy rate and Tamarix Scrub and sand-hillock were increasing.?3?The morphological parameters of Tamarix shrubs and sand-hillocks are obviously related to each other.Tamarix chinensis can promote the growth of Tamarix shrubs.In turn,the growth of Tamarix shrubs can also affect the expansion of sand-hillocks.There is a significant correlation between the age level of Tamarix japonicus?ie,the sand-hillocks layer?and the spatial share of Tamarix shrubs and sand-hillocks.2.Response of cation content of Tamarix to environmental changes?1?There is a positive correlation between the changes of cation content in litterfall of Tamarix and temperature changes,which indicates that the change of cation content of Tamarix litter can be used as an indicator of temperature change to study the change of local temperature.?2?There is also a link between litterfall cations and groundwater.From the change of content,it can reflect the change of soil water quality and groundwater level in the sampling area.3.Response of eco-chemical stoichiometry of litterfall of Tamarix to environmental changes?1?The linear relationship between TOC and TN in the litterfall of Tamarix sand-hillocks was very significant;there was no significant difference between TOC and C/N,and the linear relationship was not obvious;and there was a highly negative linear relationship between C/N and N/P.?2?The contents of TOC and TN in litterfall of Tamarix sand-hillocks decreased,and the C/N ratio increased,reflecting the increase in ambient temperature.It can also be said that the content of TOC and TN has a negative correlation with the temperature,and the C/N ratio has a positive correlation with the temperature.?3?The characteristics of TOC,TN and C/N in organic matter in the litter of Tamarix can be used as the main parameters for the study of climate change in the classification of environmental changes.Through experimental comparison,the results are also relatively reliable,which proves that this method is feasible effective.