Variation in glomalin in soil profiles and its association with climatic conditions, shelterbelt characteristics, and soil properties in poplar shelterbelts of Northeast China

Abstract

Glomalin-related soil protein (GRSP) sequesters large amounts of carbon and plays important roles in maintaining terrestrial soil ecosystem functions and ecological restoration; however, little is known about GRSP variation in 1-m soil profiles and its association with stand characteristics, soil properties, and climatic conditions, hindering GRSP-related degraded soil improvement and GRSP evaluation. In this study, we sampled soils from 1-m profiles from poplar (Populus spp.) shelterbelts in Northeast China. GRSP contents were 1.8-2.0 times higher in the upper 40 cm soil layers than at 40-100 cm. GRSP-related soil organic carbon (SOC) sequestration in deeper soil layers was * 1.2 times higher than in surface layers. The amounts of GRSP-related nutrients were similar throughout the soil profile. A redundancy analysis showed that in both surface and deeper layers, soil properties (pH, electrical conductivity, water, SOC, and soil nutrients) explained the majority of the GRSP variation (59.5-84.2%); the second-most-important factor in GRSP regulation was climatic conditions (temperature, precipitation, and altitude), while specific shelterbelt characteristics had negligible effects (\ 5%). Soil depth and climate indirectly affected GRSP features via soil properties, as manifested by structural equation model analysis. Our findings demonstrate that GRSP is important for carbon storage in deep soils, regardless of shelterbelt characteristics. Future glomalin assessments should consider these vertical patterns and possible regulating mechanisms that are related to soil properties and climatic changes. Keywords Soil depth Á Glomalin-related soil protein (GRSP) Á Soil organic carbon storage Á Climate change Á Soil improvement

Glomalin and Contribution of Glomalin to Carbon Sequestration in Soil: A Review

“…The findings show that SOC decreased with the increase of soil depth as well as forest soil always the highest results in respect of SOC, TG, and EEG except in TG up to 15 cm soil depth. Wang et al (2020) also reported that AMF produced 1.8-2.0 times higher GRSP up to 40 cm soil layer than at 40-100 cm. GRSP related SOC sequestrated 1.2 times higher in deep soil than surface soil.…”

“…Nichols and Wright (2005) reported that native grasses soil contained higher amounts of glomalin than introduced grasses soil as well as after shifted these lands to cattle, glomalin content was higher than overgrazed soils. The GRSP structures and their differences depend on the content of SOC as well as the depth of soil (Wang et al, 2020). Different pools of glomalin such as TG, immune reactive total glomalin (IRTG), EEG, and IREEG directly contribute carbon sequestration in soil (Figure 1).…”

Effects of organic mulching on soil aggregate stability and aggregate binding agents in an urban forest in Beijing, China

“…Although there are some limitations on the application of organic mulching in this study, the results can contribute to knowledge on rapid urbanization. In the short term, frequent changes in urban green spaces have affected soil quality and ecosystem functions (Gao et al 2020;Wang et al 2020a). In some cities, organic mulching measures have been used to prevent the soil dust storms in winter, and mulches would be removed in warmer weather (Zhang et al 2017).…”

“…In addition, EG/TG (easily extractable/total GRSP) ratios reflect difference in the potential accumulation of glomalin-related soil protein in soils (Liu et al 2020). TG/SOC (total GRSP/soil organic carbon) ratios and EG/SOC (easily extractable GRSP/soil organic carbon) ratios represent the contribution of glomalin-related soil protein to the total soil organic carbon pool (Wang et al 2017b(Wang et al , 2020a(Wang et al , 2020b. Wood chips alone significantly increased easily extractable/total GRSP ratios in large macroaggregates and silt + clay fractions, indicating that glomalin-related soil protein accumulation increased.…”

Dominant Species Abundance, Vertical Structure and Plant Diversity Response to Nature Forest Protection in Northeastern China: Conservation Effects and Implications

“…Selecting an appropriate statistical analysis method was crucial to decouple the associations between species diversity and forest structure and find the most likely pathway of forest structural improvement, species diversity and dominant species protection [9,22,23]. We chose structural equation modeling (SEM) to identify the structural relationship among the complex associations.…”