艾比湖高盐湖泊湿地典型植物群落下土壤呼吸规律研究

发布时间：2018-04-01 22:05

本文选题：艾比湖　切入点：土壤呼吸速率　出处：《新疆师范大学》2017年硕士论文

【摘要】：艾比湖是新疆第一大咸水湖,受到高盐、干旱、沙化和大风的影响,导致该区域土壤、植被退化严重。它的生态安全稳定直接威胁着新疆天山北坡经济带的可持续发展,同时也是重建丝绸之路经济带不可或缺的一部分。土壤呼吸是全球碳循环的重要环节,近年来,关于干旱区湖泊湿地土壤碳循环逐渐受到重视,但是对于干旱区高盐湖泊湿地土壤碳循环的研究大大滞后于其它地区。本研究在艾比湖鸟岛管护站设置垂直于湖滨向南延伸4 km的纵向样带,选取典型植物群落芦苇(Phragmites australis)和柽柳(Tamarix ramosissima)为研究对象,并设置裸地为对照组,于2015-2016年4月至11月,每月的中下旬利用碳通量监测仪LI-840A(Li-cor公司,美国)对芦苇、柽柳和裸地土壤呼吸速率进行连续24 h的监测,并记录和测定环境因子,研究土壤呼吸速率的日变化和季节变化规律,探讨影响艾比湖湿地典型植物群落土壤呼吸速率变化规律的因素,以期为科学评价干旱半干旱区土壤碳循环提供基础实验数据和依据。主要结论如下:(1)芦苇、柽柳和裸地不同生长周期土壤呼吸速率具有明显的日变化,均呈不规则的单峰曲线形式;在萌芽期、迅速生长期、生长中期、旺盛期内土壤呼吸速率日均值大小依次为芦苇柽柳裸地,而枯黄期和越冬期则为柽柳芦苇裸地。芦苇的越冬期、柽柳的萌芽期和迅速生长期以及越冬期、裸地的所有生长周期在夜间出现负值,这说明芦苇、柽柳和裸地在该监测时段内土壤以某种方式吸收空气中的CO2,产生碳汇现象。(2)芦苇、柽柳和裸地土壤呼吸速率季节变化呈明显的单峰型曲线形式,整个生长周期内,土壤呼吸速率芦苇柽柳裸地,芦苇和柽柳表现为碳排放过程,而裸地为碳吸收过程。(3)不同生长周期空气温度与芦苇、柽柳和裸地土壤呼吸速率均呈显著正相关性;而空气相对湿度与土壤呼吸速率呈显著负相关性(除芦苇、柽柳和裸地的越冬期);与土壤温度呈显著相关性,且芦苇Q10大于柽柳和裸地;与土壤含水量相关性不固定;与土壤盐分和pH呈负相关;与土壤有机碳、全磷和铵态氮均呈正相关;与芦苇和柽柳土壤硝态氮与呈负相关,而裸地呈正相关。土壤脲酶、磷酸酶、过氧化氢酶与土壤呼吸速率均呈显著或不显著正相关。(4)从整个生长周期来看,芦苇、柽柳和裸地空气温度分别在22~35、23~30、24~34℃时,土壤温度分别在21~33、21~29、23~36℃时,土壤含水量分别在3.8~14.9、2.2~24.9、0.2~10.9%时,有机碳含量在12.8~26.8、26.3~40.6、1.4~8 g/kg范围内、脲酶分别达到0.18、0.14、0.1 mg/kg以上,磷酸酶分别达到0.33、0.75、0.03 mg/kg以上,过氧化氢酶分别达到2.05、5.59、2.57 mg/kg以上会促进土壤呼吸速率的产生;而当空气相对湿度分别在42~69、52~75、33~80%时,盐分分别达到24.7(盐土20 g/kg)、22.5(盐土)和7.6(中度盐渍化6~10 g/kg)以上,pH值达到7.4以上会抑制土壤呼吸速率的产生。(5)芦苇在不同生长周期影响其土壤呼吸速率日变化主导因子有土壤温度、土壤含水量、空气温度;柽柳则为土壤温度、空气相对湿度和土壤含水量;裸地为土壤温度和空气温湿度;而影响芦苇土壤呼吸速率季节变化的环境因子为空气温度和空气相对湿度;柽柳为空气温度、土壤温度、铵态氮;裸地是由土壤温度、硝态氮和过氧化氢酶起主导作用。(6)艾比湖高盐湖泊生长季均表现出碳排放过程(除艾比湖裸地);生长季芦苇、柽柳和裸地的CO2增温潜势GWPs分别为650.58、412.22和-3.97kg CO2/hm2,相对于其他研究区其排放量较小,对增强温室效应的能力较小。
[Abstract]:Ebinur Lake is Xinjiang's largest saltwater lake, by high salinity, drought, desertification and the effects of strong winds, resulting in the regional soil, serious vegetation degradation. The ecological security and stability it directly threatens the sustainable development of the economic belt on the northern slope of the Tianshan Mountains in Xinjiang, but also the reconstruction of the Silk Road Economic Zone part of soil respiration is an important indispensable. Part of the global carbon cycle in recent years, in arid areas of Lake wetland soil carbon cycle has been paid more and more attention, but for the study of soil carbon cycling in arid area of high salt lake wetland has lagged behind other regions. This research station is arranged perpendicular to the longitudinal Lake extends southward like 4 km band in the Ebinur Lake Island and typical plants reed (Phragmites australis) and community Tamarix (Tamarix ramosissima) as the research object, and set the bare land as the control group, in the 2015-2016 years from April to November, every month in the late LI-840A carbon flux monitor (Li-cor company, USA) of reed, Tamarix chinensis and soil respiration rate of bare land was continuously monitored in 24 h, and record and determination of environmental factors, diurnal and seasonal variation of soil respiration rate, to explore influencing factors of the Ebinur Lake wetland plant communities were typical variation of soil respiration rate in order. Provide basic experimental data and the basis for soil carbon cycling in semi arid area of scientific evaluation of drought. The main conclusions are as follows: (1) reed, Tamarix chinensis and bare soil respiration rate in different growth period has obvious change, showed a single peak curve form irregular; in the germination period, growth period, growth period, soil respiration rate the daily mean size of exuberant period followed by reed Tamarix bare land, yellow and wintering period for Tamarix reed bare land. Winter reed, Tamarix chinensis germination period and the period of rapid growth and more In winter, all the growth cycle of bare land is negative in the night, the reed, Tamarix and bare in the monitoring period of soil in some way in the air to absorb CO2, produce carbon sink phenomenon. (2) reed, Tamarix chinensis and bare soil respiration rate change season showed a single peak curve form obvious, the whole growth cycle in the soil respiration rate of Tamarix Tamarix and reed reed land, for carbon emissions, and bare land as carbon sequestration. (3) in different growth periods of air temperature and reed, Tamarix and bare soil respiration rate showed a significant positive correlation; and the air relative humidity and soil respiration rate showed a significant negative correlation (except reed, Tamarix and bare in winter); showed significant correlation with soil temperature, and reed Q10 greater than Tamarix and bare soil; and soil moisture correlation is not fixed; and negatively correlated with soil salinity and soil pH and soil organic carbon, The total phosphorus and ammonium nitrogen were positively correlated with reed and Tamarix; soil nitrate nitrogen and negatively related, and bare land were positively correlated. Soil urease, phosphatase, was not significantly correlated with catalase. Soil respiration rate was (4) reed from the whole growth cycle, Tamarix, and bare air temperature at 22~35,23~30,24~34 DEG C, soil temperature respectively at 21~33,21~29,23~36 DEG C, soil moisture in 3.8~14.9,2.2~24.9,0.2~10.9%, organic carbon content in the 12.8~26.8,26.3~40.6,1.4~8 g/kg range, urease reached 0.18,0.14,0.1 above mg/kg, phosphatase reached 0.33,0.75,0.03 above mg/kg, catalase reached 2.05,5.59,2.57 above mg/kg will promote the soil respiration rate; and when the air the relative humidity in 42~69,52~75,33~80%, salinity reached 24.7 (20 g/kg, 22.5 (saline) and saline (7.6) 6~10 g/kg), moderate Salinization Soil pH value reached more than 7.4 inhibited soil respiration rate. (5) reed in the different growth cycle affect the soil respiration rate of dominant factor of soil temperature, soil moisture, air temperature, soil temperature; Tamarix, air relative humidity and soil water content for bare land; soil temperature and air temperature and humidity; environmental factors affect the change of soil respiration rate for reed seasonal air temperature and relative humidity; for Tamarix air temperature, soil temperature, soil ammonium nitrogen; by soil temperature, nitrate nitrogen and hydrogen peroxide enzyme plays a leading role. (6) the Ebinur Lake High Salt Lake Ji Jun show the carbon emissions (except the Ebinur Lake bare land); growth Ji Luwei, Tamarix and bare CO2 warming potential of GWPs 650.58412.22 and -3.97kg CO2/hm2 respectively, compared to the other of its emissions is small, to increase The power of a strong greenhouse effect is small.

【学位授予单位】：新疆师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q948.1

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