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Effect of Precipitation Variation on Soil Respiration in Rain-Fed Winter Wheat Systems on the Loess Plateau, China. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19116915. [PMID: 35682496 PMCID: PMC9180287 DOI: 10.3390/ijerph19116915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/02/2022] [Accepted: 06/02/2022] [Indexed: 11/18/2022]
Abstract
Global climate change has aggravated the hydrological cycle by changing both the amount and distribution of precipitation, and this is especially notable in the semiarid Loess Plateau. How these precipitation variations have affected soil carbon (C) emission by the agroecosystems is still unclear. Here, to evaluate the effects of precipitation variation on soil respiration (Rs), a field experiment (from 2019 to 2020) was conducted with 3 levels of manipulation, including ambient precipitation (CK), 30% decreased precipitation (P−30), and 30% increased precipitation (P+30) in rain-fed winter wheat (Triticum aestivum L.) agroecosystems on the Loess Plateau, China. The results showed that the average Rs in P−30 treatment was significantly higher than those in the CK and P+30 treatments (p < 0.05), and the cumulative CO2 emissions were 406.37, 372.58 and 383.59 g C m−2, respectively. Seasonal responses of Rs to the soil volumetric moisture content (VWC) were affected by the different precipitation treatments. Rs was quadratically correlated with the VWC in the CK and P+30 treatments, and the threshold of the optimal VWC for Rs was approximately 16.06−17.07%. However, Rs was a piecewise linear function of the VWC in the P−30 treatment. The synergism of soil temperature (Ts) and VWC can better explain the variation in soil respiration in the CK and P−30 treatments. However, an increase in precipitation led to the decoupling of the Rs responses to Ts. The temperature sensitivity of respiration (Q10) varied with precipitation variation. Q10 was positive correlated with seasonal Ts in the CK and P+30 treatments, but exhibited a negative polynomial correlation with seasonal Ts in the P−30 treatment. Rs also exhibited diurnal clockwise hysteresis loops with Ts in the three precipitation treatments, and the seasonal dynamics of the diurnal lag time were significantly negatively correlated with the VWC. Our study highlighted that understanding the synergistic and decoupled responses of Rs and Q10 to Ts and VWC and the threshold of the change in response to the VWC under precipitation variation scenarios can benefit the prediction of future C balances in agroecosystems in semiarid regions under climate change.
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Yan T, Song H, Wang Z, Teramoto M, Wang J, Liang N, Ma C, Sun Z, Xi Y, Li L, Peng S. Temperature sensitivity of soil respiration across multiple time scales in a temperate plantation forest. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 688:479-485. [PMID: 31254813 DOI: 10.1016/j.scitotenv.2019.06.318] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 06/20/2019] [Accepted: 06/20/2019] [Indexed: 06/09/2023]
Abstract
Soil respiration (Rs) is the largest carbon (C) flux from terrestrial ecosystems to the atmosphere. Predictions of Rs and associated feedback to climate change remain largely uncertain, in part due to the high temporal heterogeneity of temperature sensitivity (apparent Q10) of Rs under a changing climate. Therefore, it is of critical importance to provide better insight into how Q10 varies across multiple temporal scales. We investigated the diurnal, seasonal, and annual variabilities in the Q10 of Rs using continuous Rs measurements (at hourly intervals) over six growing seasons in a mature temperate larch plantation in North China. We found that night-time values of Q10 were slightly lower than daytime values. Large seasonal and annual fluctuations of Q10 were observed, as illustrated by high coefficients of variation of 15.0% and 21.8%, respectively. The higher Q10 in spring and autumn were primarily regulated by fine root growth and higher soil moisture after snow melt in spring, and leaf senescence in autumn. Lower Q10 in summer may have been caused by limitations in substrate availability and microbial activity resulting from drought, which also caused a decoupling of Rs from soil temperature in summer. Furthermore, a bivariate nonlinear model incorporating both soil temperature and soil moisture best explained Q10 variability. Generally, lower soil temperature and higher soil moisture lead to higher values of Q10, indicating that climate warming could exert a negative effect on Q10, partially offsetting the warming-induced increase in soil C loss. We provide long-term field experimental evidence that it would be inappropriate to estimate Rs on a multiyear scale using a fixed Q10 value or a value obtained from one season and/or one year. Thus, we emphasize the importance of incorporating the seasonal and annual heterogeneities of Q10 into C cycle model simulations under future climate change scenarios.
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Affiliation(s)
- Tao Yan
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Huanhuan Song
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Shenyang 110016, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaoqi Wang
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Munemasa Teramoto
- Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan
| | - Jinsong Wang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Naishen Liang
- Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan
| | - Chao Ma
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Zhenzhong Sun
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Yi Xi
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Lili Li
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Shushi Peng
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
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Diurnal and Seasonal Variations in Soil Respiration of Four Plantation Forests in an Urban Park. FORESTS 2019. [DOI: 10.3390/f10060513] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Understanding the carbon dynamics of urban trees and forests is one of the key components for developing mitigation strategies for climate change in a fast-paced urbanized world. This study selected four plantation forests composed of poplar, black locust, Chinese pine and mixture of poplar and black locust, located in an urban forest park on a well-drained fluvial plain with same land-use history. The diurnal and seasonal changes in soil respiration (Rs) and biophysical factors were measured from April 2015 to March 2016. At the diurnal scale, Rs varied out of phase with soil temperature (Ts) and the time-lag occurred in May and July when Ts was relatively high and soil moisture (Ms) was low. Strong seasonal variations in Rs were mainly determined by Ts, while the growing-season mean Rs positively correlated with the fine root biomass (FRB), soil organic carbon content (SOC), and total nitrogen content (TN) for all the forests. FRB alone could explain 75% of the among-stand variability. This study concluded that urban forest plantations have similar soil respiration dynamics to forest ecosystems in non-urban settings.
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Guan C, Li X, Zhang P, Chen Y. Diel hysteresis between soil respiration and soil temperature in a biological soil crust covered desert ecosystem. PLoS One 2018; 13:e0195606. [PMID: 29624606 PMCID: PMC5889175 DOI: 10.1371/journal.pone.0195606] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 03/26/2018] [Indexed: 11/25/2022] Open
Abstract
Soil respiration induced by biological soil crusts (BSCs) is an important process in the carbon (C) cycle in arid and semi-arid ecosystems, where vascular plants are restricted by the harsh environment, particularly the limited soil moisture. However, the interaction between temperature and soil respiration remains uncertain because of the number of factors that control soil respiration, including temperature and soil moisture, especially in BSC-dominated areas. In this study, the soil respiration in moss-dominated crusts and lichen-dominated crusts was continuously measured using an automated soil respiration system over a one-year period from November 2015 to October 2016 in the Shapotou region of the Tengger Desert, northern China. The results indicated that over daily cycles, the half-hourly soil respiration rates in both types of BSC-covered areas were commonly related to the soil temperature. The observed diel hysteresis between the half-hourly soil respiration rates and soil temperature in the BSC-covered areas was limited by nonlinearity loops with semielliptical shapes, and soil temperature often peaked later than the half-hourly soil respiration rates in the BSC-covered areas. The average lag times between the half-hourly soil respiration rates and soil temperature for both types of BSC-covered areas were two hours over the diel cycles, and they were negatively and linearly related to the volumetric soil water content. Our results highlight the diel hysteresis phenomenon that occurs between soil respiration rates and soil temperatures in BSC-covered areas and the negative response of this phenomenon to soil moisture, which may influence total C budget evaluations. Therefore, the interactive effects of soil temperature and moisture on soil respiration in BSC-covered areas should be considered in global carbon cycle models of desert ecosystems.
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Affiliation(s)
- Chao Guan
- Shapotou Desert Research and Experimental Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu, China
- University of Chinese Academy of Sciences, Beijing, China
- * E-mail:
| | - Xinrong Li
- Shapotou Desert Research and Experimental Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu, China
| | - Peng Zhang
- Shapotou Desert Research and Experimental Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu, China
| | - Yongle Chen
- Shapotou Desert Research and Experimental Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu, China
- University of Chinese Academy of Sciences, Beijing, China
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López-Serrano FR, Rubio E, Dadi T, Moya D, Andrés-Abellán M, García-Morote FA, Miettinen H, Martínez-García E. Influences of recovery from wildfire and thinning on soil respiration of a Mediterranean mixed forest. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 573:1217-1231. [PMID: 27179619 DOI: 10.1016/j.scitotenv.2016.03.242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 03/30/2016] [Accepted: 03/31/2016] [Indexed: 06/05/2023]
Abstract
The ecosystem recovery after wildfire and thinning practices are both key processes that have great potential to influence fluxes and storage of carbon within Mediterranean semiarid ecosystems. In this study, started 7years after a wildfire, soil respiration (SR) patterns measured from 2008 to 2010 were compared between an unmanaged-undisturbed mature forest stand (UB site) and a naturally regenerated post-wildfire stand (B site) in a Mediterranean mixed forest in Spain. The disturbed stand included a control zone (unthinned forest, BUT site) and a thinned zone (BT site). Our results indicated that SR was lower at naturally regenerated after fire sites (BUT and BT) than at unburnt one. Soil under the canopy layer of pine and oak trees exhibited higher SR rates than bare or herbaceous layer soils, regardless of the site. The effect of thinning was only manifest, with a significant increase of SR, during the 1st year after thinning practices. SR showed a clear soil temperature-dependent seasonal pattern, which was strongly modulated by soil water content (SWC), especially in summer. Site-specific polynomial regression models were defined to describe SR responses, being mainly controlled by both soil temperature (Ts) and SWC at UB site, or Ts at burnt sites. The sensitivity of SR rate to Ts variations (Q10) ranged between 0.20 and 6.89, with mean annual values varying between 0.92 and 1.35. Q10 values were higher at BT than at UB-BUT sites. The results revealed a significant, non-linear dependence, of Q10 on both Ts and SWC at UB site, and on Ts at both burnt sites. This study contributes to (i) improve the understanding of how natural recovery and management practices affect soil respiration in a Mediterranean forest during their early stages after fire disturbance and (ii) highlight the importance of Q10 values <1 which emphasizes drought stress effect on SR temperature sensitivity.
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Affiliation(s)
- F R López-Serrano
- Department of Science and Agroforestry Technology and Genetics, Higher Technical School of Agricultural and Forestry Engineering, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain; Environmental Department, Renewable Energy Research Institute, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain
| | - E Rubio
- Department of Applied Physics, School of Industrial Engineering, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain.
| | - T Dadi
- Department of Science and Agroforestry Technology and Genetics, Higher Technical School of Agricultural and Forestry Engineering, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain; Environmental Department, Renewable Energy Research Institute, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain
| | - D Moya
- Department of Plant Production, Higher Technical School of Agricultural and Forestry Engineering, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain
| | - M Andrés-Abellán
- Department of Science and Agroforestry Technology and Genetics, Higher Technical School of Agricultural and Forestry Engineering, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain; Environmental Department, Renewable Energy Research Institute, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain
| | - F A García-Morote
- Department of Science and Agroforestry Technology and Genetics, Higher Technical School of Agricultural and Forestry Engineering, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain; Environmental Department, Renewable Energy Research Institute, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain
| | - H Miettinen
- Department of Science and Agroforestry Technology and Genetics, Higher Technical School of Agricultural and Forestry Engineering, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain; Environmental Department, Renewable Energy Research Institute, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain
| | - E Martínez-García
- Department of Science and Agroforestry Technology and Genetics, Higher Technical School of Agricultural and Forestry Engineering, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain; Environmental Department, Renewable Energy Research Institute, University of Castilla-La Mancha, Campus Universitario s/n, CP 02071 Albacete, Spain
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Chen J, Wang Q, Li M, Liu F, Li W. Does the different photosynthetic pathway of plants affect soil respiration in a subtropical wetland? Ecol Evol 2016; 6:8010-8017. [PMID: 27878073 PMCID: PMC5108253 DOI: 10.1002/ece3.2523] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 09/01/2016] [Indexed: 11/10/2022] Open
Abstract
Plants with different photosynthetic pathways could produce different amounts and types of root exudates and debris which may affect soil respiration rates. Therefore, wetland vegetation succession between plants with different photosynthetic pathways may ultimately influence the wetland carbon budget. The middle and lower reaches of the Yangtze River has the largest floodplain wetland group in China. Tian'e Zhou wetland reserve (29°48'N, 112°33′E) is located in Shishou city, Hubei province and covers about 77.5 square kilometers. Hemathria altissima (C4) was found gradually being replaced by Carex argyi (C3) for several years in this place. An in situ experiment was conducted in Tian'e Zhou wetland to determine the change of soil respiration as the succession proceeds. Soil respiration, substrate‐induced respiration, and bacterial respiration of the C4 species was greater than those of the C3 species, but below‐ground biomass and fungal respiration of the C4 species was less than that of the C3 species. There were no significant differences in above‐ground biomass between the two species. Due to the higher photosynthesis capability, higher soil respiration and lower total plant biomass, we inferred that the C4 species, H. altissima, may transport more photosynthate below‐ground as a substrate for respiration. The photosynthetic pathway of plants might therefore play an important role in regulating soil respiration. As C. argyi replaces H. altissima, the larger plant biomass and lower soil respiration would indicate that the wetland in this area could fix more carbon in the soil than before.
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Affiliation(s)
- Jingrui Chen
- Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical Garden Chinese Academy of Sciences Wuhan Hubei China; Institute of Soil & Fertilizer and Resources & Environment Jiangxi Academy of Agricultural Sciences Nanchang Jiangxi China
| | - Qiulin Wang
- Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical Garden Chinese Academy of Sciences Wuhan Hubei China; Jiangxi Academy of Sciences Nanchang Jiangxi China
| | - Ming Li
- Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical Garden Chinese Academy of Sciences Wuhan Hubei China
| | - Fan Liu
- Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical Garden Chinese Academy of Sciences Wuhan Hubei China
| | - Wei Li
- Hubei Key Laboratory of Wetland Evolution & Ecological Restoration Wuhan Botanical Garden Chinese Academy of Sciences Wuhan Hubei China
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Chen J, Shi W, Cao J. Effects of grazing on ecosystem CO₂ exchange in a meadow grassland on the Tibetan Plateau during the growing season. ENVIRONMENTAL MANAGEMENT 2015; 55:347-59. [PMID: 25355630 DOI: 10.1007/s00267-014-0390-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 10/15/2014] [Indexed: 05/20/2023]
Abstract
Effects of human activity on ecosystem carbon fluxes (e.g., net ecosystem exchange (NEE), ecosystem respiration (R(eco)), and gross ecosystem exchange (GEE)) are crucial for projecting future uptake of CO2 in terrestrial ecosystems. However, how ecosystem that carbon fluxes respond to grazing exclusion is still under debate. In this study, a field experiment was conducted to study the effects of grazing exclusion on R(eco), NEE, and GEE with three treatments (free-range grazing (FG) and grazing exclusion for 3 and 5 years (GE3 and GE5, respectively)) in a meadow grassland on the Tibetan Plateau. Our results show that grazing exclusion significantly increased NEE by 47.37 and 15.84%, and R eco by 33.14 and 4.29% under GE3 and GE5 plots, respectively, although carbon sinks occurred in all plots during the growing season, with values of 192.11, 283.12, and 222.54 g C m(-2) for FG, GE3, and GE5, respectively. Interestingly, grazing exclusion increased temperature sensitivity (Q10) of R eco with larger increases at the beginning and end of growing season (i.e., May and October, respectively). Soil temperature and soil moisture were key factors on controlling the diurnal and seasonal variations of R(eco), NEE, and GEE, with soil temperature having a stronger influence. Therefore, the combined effects of grazing and temperature suggest that grazing should be taken into consideration in assessing global warming effects on grassland ecosystem CO2 exchange.
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Affiliation(s)
- Ji Chen
- State Key Laboratory of Loess and Quaternary Geology (SKLLQG), and Key Laboratory of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710075, China
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Escolar C, Maestre FT, Rey A. Biocrusts modulate warming and rainfall exclusion effects on soil respiration in a semi-arid grassland. SOIL BIOLOGY & BIOCHEMISTRY 2015; 80:9-17. [PMID: 25914428 PMCID: PMC4405768 DOI: 10.1016/j.soilbio.2014.09.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Soil surface communities composed of cyanobacteria, algae, mosses, liverworts, fungi, bacteria and lichens (biocrusts) largely affect soil respiration in dryland ecosystems. Climate change is expected to have large effects on biocrusts and associated ecosystem processes. However, few studies so far have experimentally assessed how expected changes in temperature and rainfall will affect soil respiration in biocrust-dominated ecosystems. We evaluated the impacts of biocrust development, increased air temperature and decreased precipitation on soil respiration dynamics during dry (2009) and wet (2010) years, and investigated the relative importance of soil temperature and moisture as environmental drivers of soil respiration, in a semiarid grassland from central Spain. Soil respiration rates were significantly lower in the dry than during the wet year, regardless of biocrust cover. Warming increased soil respiration rates, but this response was only significant in biocrust-dominated areas (> 50% biocrust cover). Warming also increased the temperature sensitivity (Q10 values) of soil respiration in biocrust-dominated areas, particularly during the wet year. The combination of warming and rainfall exclusion had similar effects in low biocrust cover areas. Our results highlight the importance of biocrusts as a modulator of soil respiration responses to both warming and rainfall exclusion, and indicate that they must be explicitly considered when evaluating soil respiration responses to climate change in drylands.
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Affiliation(s)
- Cristina Escolar
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Física y Química Inorgánica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, E-28933 Móstoles, Spain
| | - Fernando T. Maestre
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Física y Química Inorgánica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, E-28933 Móstoles, Spain
| | - Ana Rey
- Department of Biogeography and Global Change, Museo de Ciencias Naturales, C.S.I.C., Serrano 115, 28006 Madrid, Spain
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Feng W, Zhang Y, Jia X, Wu B, Zha T, Qin S, Wang B, Shao C, Liu J, Fa K. Impact of environmental factors and biological soil crust types on soil respiration in a desert ecosystem. PLoS One 2014; 9:e102954. [PMID: 25050837 PMCID: PMC4106843 DOI: 10.1371/journal.pone.0102954] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 06/25/2014] [Indexed: 11/19/2022] Open
Abstract
The responses of soil respiration to environmental conditions have been studied extensively in various ecosystems. However, little is known about the impacts of temperature and moisture on soils respiration under biological soil crusts. In this study, CO2 efflux from biologically-crusted soils was measured continuously with an automated chamber system in Ningxia, northwest China, from June to October 2012. The highest soil respiration was observed in lichen-crusted soil (0.93 ± 0.43 µmol m-2 s-1) and the lowest values in algae-crusted soil (0.73 ± 0.31 µmol m-2 s-1). Over the diurnal scale, soil respiration was highest in the morning whereas soil temperature was highest in the midday, which resulted in diurnal hysteresis between the two variables. In addition, the lag time between soil respiration and soil temperature was negatively correlated with the soil volumetric water content and was reduced as soil water content increased. Over the seasonal scale, daily mean nighttime soil respiration was positively correlated with soil temperature when moisture exceeded 0.075 and 0.085 m3 m-3 in lichen- and moss-crusted soil, respectively. However, moisture did not affect on soil respiration in algae-crusted soil during the study period. Daily mean nighttime soil respiration normalized by soil temperature increased with water content in lichen- and moss-crusted soil. Our results indicated that different types of biological soil crusts could affect response of soil respiration to environmental factors. There is a need to consider the spatial distribution of different types of biological soil crusts and their relative contributions to the total C budgets at the ecosystem or landscape level.
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Affiliation(s)
- Wei Feng
- Yanchi Research Station, College of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Yuqing Zhang
- Yanchi Research Station, College of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Xin Jia
- Yanchi Research Station, College of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Bin Wu
- Yanchi Research Station, College of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Tianshan Zha
- Yanchi Research Station, College of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Shugao Qin
- Yanchi Research Station, College of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Ben Wang
- Yanchi Research Station, College of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Chenxi Shao
- Yanchi Research Station, College of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Jiabin Liu
- Yanchi Research Station, College of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Keyu Fa
- Yanchi Research Station, College of Soil and Water Conservation, Beijing Forestry University, Beijing, China
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