摘要
【目的】蘑菇圈是草原上常见的生态学景观,蘑菇圈的真菌不仅会影响植物的生长,而且会极大地改变土壤理化性质和微生物群落,从而间接影响土壤呼吸。探究草原蘑菇圈的土壤呼吸作用,为精确估算草地土壤温室气体排放提供科学依据。【方法】采用Li-8100土壤呼吸监测系统,对呼伦贝尔草甸草原蘑菇圈不同位置(圈上、圈内、圈外)的土壤呼吸作用进行监测,并使用探针式电子温度计(CJTP-101)和手持式土壤水分仪测量土壤温度和土壤含水量,同时测定蘑菇圈土壤生物量和土壤养分,探讨它们之间的相关性。【结果】蘑菇圈上的地上生物量为246.2 g·m^-2,显著高于圈内(153.1 g·m^-2)和圈外(132.6 g·m^-2),圈上地上生物量分别为圈内和圈外的1.61倍和1.86倍;蘑菇圈上地下生物量为763.9 g·m^-2,小于圈内(927.4 g·m^-2)和圈外(824.8 g·m^-2),圈上、圈内、圈外地下生物量差异不显著(P>0.05);蘑菇圈上枯落物量为17.9 g·m^-2,大于圈内(13.1 g·m^-2)和圈外(9.6 g·m^-2),但差异不显著(P>0.05);圈上土壤速效氮和速效磷的含量分别为52.2和7.8 mg·kg^-1,显著高于圈内和圈外(P<0.05),速效氮的含量分别比圈内、外平均值高42%和40%,速效磷的含量分别比圈内、外平均值高53%和59%;蘑菇圈上土壤有机质和全氮含量分别为3560.1和319.8 mg·kg^-1,均低于圈内和圈外;而全磷含量为502.2 mg·kg^-1,高于圈内和圈外,但均无显著差异(P>0.05)。草原蘑菇圈上平均土壤呼吸速率为5.26μmol·m^-2·s^-1,显著大于圈内(4.07μmol·m^-2·s^-1)和圈外(4.17μmol·m^-2·s^-1),土壤呼吸速率与土壤温度和土壤含水量之间分别存在显著的指数和线性回归关系(P<0.01)。【结论】土壤温度和水分不是造成蘑菇圈土壤呼吸速率差异性的主导要素,蘑菇圈上的土壤呼吸速率增强与圈上较高的速效养分和较强的微生物活性及酶活性有关。
【Objective】Circles of mushrooms coupled with regular rings or arcs of greener plants are commonly observed in grassland.This pattern is often referred to as‘fairy rings’.Indeed,fairy ring funguses not only affect plant growth but also greatly modify the soil quality and microbial populations,thus indirectly have impact on soil respiration.The aim of this study was to observe soil respiration of the fairy rings to accurately estimate greenhouse gas emissions from grassland soil.【Method】Measurement of soil respiration of the outside(OUT),on(ON)and inside(IN)the rings was conducted by Li-8100 automatic instrument.Meanwhile,soil temperature and soil water content were measured by the monitoring instrument CJTP-101 and TDR 300.The biomass and soil nutrients through field investigation on fairy rings were also measured.【Result】The average aboveground biomass of ON zone was 246.2 g·m^-2,significantly higher than that of IN(153.1 g·m^-2)and OUT(132.6 g·m^-2)zones,which was 1.62 times of IN zone and 1.86 times of OUT zone.The average belowground biomass of ON zone was 763.9 g·m^-2,less than that of IN(927.4 g·m^-2)and OUT(824.8 g·m^-2)zones,and there was no significant difference(P>0.05)of the belowground biomass among them.The litter of ON zone was 17.9 g·m^-2,higher than that of IN(13.1 g·m^-2)and OUT(9.6 g·m^-2)zones,and there was no significant difference in different zones(P>0.05).The available nitrogen and phosphorus of ON zone were 52.2 and 7.8 mg·kg^-1,significantly higher than that in IN and OUT zones(P>0.05),respectively.The available nitrogen was 42%and 40%higher than the IN and OUT zones,and the available phosphorus was 53%and 59%higher than the IN and OUT zones,respectively.The organic matter and total nitrogen of ON zone were 3560.1 and 319.8 mg·kg^-1,respectively,less than that in IN and OUT zones.The total phosphorus of ON zone was 502.2 mg·kg^-1,higher than the IN and OUT zones,but the difference was not significant(P>0.05).The average soil respiration rate(SRR)of ON zone was 5.26μmol·m^-2·s^-1,significantly higher than IN and OUT zones which were 4.07 and 4.17μmol·m^-2·s^-1,respectively.The significantly relationship were found between the SRR and soil temperature and soil water content(P<0.01).【Conclusion】It was suggested that the soil temperature and soil water content were not the dominant factors.And the enhancement of soil respiration in the ON zone was related to the higher available nutrients and stronger microbial and enzyme activities.
作者
范凯凯
佟旭泽
闫玉春
辛晓平
王旭
FAN KaiKai;TONG XuZe;YAN YuChun;XIN XiaoPing;WANG Xu(National Hulunber Grassland Ecosystem Observation and Research Station/Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 100081)
出处
《中国农业科学》
CAS
CSCD
北大核心
2020年第13期2595-2603,共9页
Scientia Agricultura Sinica
基金
国家重点研发计划(2016YFC0500603,2017YFC0503906,2017YFE0104500)、中国农业科学院基本科研业务费专项(1610132020028)。
关键词
蘑菇圈
草地生态系统
土壤呼吸
温度
土壤含水量
土壤养分
fairy rings
grassland ecosystem
soil respiration
temperature
soil water content
soil nutrient
