Soil Diversity (Pedodiversity) and Ecosystem Services

Pedogenesis of typical zonal soil drives belowground bacterial communities of arable land in the Northeast China Plain

Belowground bacterial communities play essential roles in maintaining ecosystem multifunction, while our understanding of how and why their distribution patterns and community compositions may change with the distinct pedogenetic conditions of different soil types is still limited. Here, we evaluated the roles of soil physiochemical properties and biotic interactions in driving belowground bacterial community composition across three typical zonal soil types, including black calcium soil (QS), typical black soil (HL) and dark brown soil (BQL), with distinct pedogenesis on the Northeast China Plain. Changes in soil bacterial diversity and community composition in these three zonal soil types were strongly correlated with soil pedogenetic features. SOC concentrations in HL were higher than in QS and BQL, but bacterial diversity was low, and the network structure revealed greater stability and connectivity. The composition of the bacterial community correlated significantly with soil pH in QS but with soil texture in BQL. The bacterial co-occurrence network of HL had higher density and clustering coefficients but lower edges, and different keystone species of networks were also detected. This work provides a basic understanding of the driving mechanisms responsible for belowground bacterial biodiversity and distribution patterns over different pedogenetic conditions in agroecosystems.

Vermont Global Warming Solutions Act: The Costs of Inaction from Land Conversions

The Vermont (VT) Global Warming Solutions Act (GWSA, 2020) sets greenhouse gas (GHG) emissions reduction targets at 26% below 2005 by 2025, 40% below 1990 by 2030 and 80% below 1990 by 2050 for energy-related emissions only. Vermont’s omission of GHG emissions from land conversions could result in significant costs of inaction (COI), which could hinder the state’s mitigation and adaptation plans and result in climate crisis-related risks (e.g., credit downgrade). Science-based spatio-temporal data of GHG emissions from soils because of land conversions can be integrated into the conceptual framework of “action” versus “inaction” to prevent GHG emissions. The application of soil information data and remote sensing analysis can identify the GHG emissions from land conversions, which can be expressed as “realized” social costs of “inaction”. This study demonstrates the rapid assessment of the value of regulating ecosystems services (ES) from soil organic carbon (SOC), soil inorganic carbon (SIC), and total soil carbon (TSC) stocks, based on the concept of the avoided social cost of carbon dioxide (CO2) emissions for VT by soil order and county using remote sensing and information from the State Soil Geographic (STATSGO) and Soil Survey Geographic Database (SSURGO) databases. Classified land cover data for 2001 and 2016 were downloaded from the Multi-Resolution Land Characteristics Consortium (MRLC) website. These results provide accurate and quantitative spatio-temporal information about likely GHG emissions, which can be linked to VT’s climate action plan. A failure to considerably reduce emissions from land conversions would increase climate change costs and potential legal consequences for VT and beyond its borders.

Delaware’s Climate Action Plan: Omission of Source Attribution from Land Conversion Emissions

Delaware’s (DE) Climate Action Plan lays out a pathway to reduce greenhouse gas (GHG) emissions by at least 26% by 2025 but does not consider soil-based GHG emissions from land conversions. Consequently, DE’s climate action plan fails to account for the contribution of emissions from ongoing land development economic activity to climate change. Source attribution (SA) is a special field within the science of climate change attribution, which can generate “documentary evidence” (e.g., GHG emissions inventory, etc.). The combination of remote sensing and soil information data analysis can identify the source attribution of GHG emissions from land conversions for DE. Traditional attribution science starts with climate impacts, which are then linked to source attribution of GHG emissions. The most urgent need is not only to detect climate change impacts, but also to detect and attribute sources of climate change impacts. This study used a different approach that quantified past soil GHG emissions which are then available to support impact attribution. Study results provide accurate and quantitative spatio-temporal source attribution for likely GHG emissions, which can be included in the DE’s climate action plan. Including the impact of land conversion on GHG emissions is critical to mitigating climate impacts, because without a more complete source attribution it is not possible to meet overall emission reduction goals. Furthermore, the increased climate change impacts from land conversions are in a feedback loop where climate change can increase the rates of GHG emissions as part of these conversions. This study provides a spatially explicit methodology that could be applied to attribute past, future, or potential GHG emission impacts from land conversions that can be included in DE’s GHGs inventory and climate impact assessment.

Massachusetts Roadmap to Net Zero: Accounting for Ownership of Soil Carbon Regulating Ecosystem Services and Land Conversions

The state of Massachusetts (MA) has passed comprehensive climate change legislation and a roadmap of achieving Net Zero emissions in 2050, which includes the protection of environmental resources (e.g., soil) and green space across the state. Soil resources are an integral part of the land cover/land use. They can be a significant source of greenhouse gas (GHG) emissions because of the conversion of “low disturbance” land covers (e.g., evergreen forest, hay/pasture) to “high disturbance” land covers (e.g., low-, medium-, and high-intensity developed land). These often “invisible” GHG emissions can be considered as “negative externalities” and “external costs” because of the difficulty in assigning ownership to the emissions. The combination of remote sensing and soil information data analysis can identify the ownership associated with GHG emissions and therefore expand the range of policy tools for addressing these emissions. This study demonstrates the rapid assessment of the value of regulating ecosystems services (ES) from soil organic carbon (SOC), soil inorganic carbon (SIC), and total soil carbon (TSC) stocks, based on the concept of the avoided social cost of carbon dioxide (CO2) emissions for MA by soil order and county using remote sensing and information from the State Soil Geographic (STATSGO) and Soil Survey Geographic Database (SSURGO) databases. Classified land cover data for 2001 and 2016 were downloaded from the Multi-Resolution Land Characteristics Consortium (MRLC) website. The results provide accurate and quantitative spatio-temporal information about likely GHG emissions, which can be linked to ownership. The state of MA can use these remote sensing tools and publicly available data to quantify and value GHG emissions based on property ownership, therefore “internalizing” the costs of these emissions for a cost-effective climate mitigation policy.

Optimization of Reclamation Measures in a Mining Area by Analysis of Variations in Soil Nutrient Grades under Different Types of Land Usage—A Case Study of Pingshuo Coal Mine, China

The development of reclaimed mine soils is normally spatially heterogeneous, making the fine management and utilization of reclaimed mined lands difficult. Soil nutrient grading can provide a scientific basis for the precise regulation of soil nutrients, but few related studies are available in reclaimed mined areas. This study aimed to quantify the spatiotemporal variations in soil nutrient grades under different land-use types in a reclaimed mined area on the Loess Plateau, China. The study area was graded by four soil nutrients (soil available potassium (SAK), soil available phosphorus (SAP), soil total nitrogen (STN), and soil organic matter (SOM)), and the variation features of soil nutrient grades in the initial stage of reclamation under four land-use types (i.e., cultivated land, grassland, forestland, and barren land) were systematically characterized by geostatistical analysis, pedodiversity analysis, and correspondence analysis. The results show that during the initial five years after reclamation, the soil nutrient grades of most reclaimed areas increased from Grade V and VI to Grade I–IV, while the improvements were significantly heterogeneous. Notably, the four land-use types had distinct variation characteristics. The barren land had the lowest SAP level, whereas it had the highest proportion, and medium–high grades of SAK, STN, and SOM (88.3, 100.0, and 100.0%, respectively). In terms of quantitative structure, it had the lowest richness index (S′, 2.5) and Shannon’s entropy index (H′, 0.7) and the highest evenness index (E′, 0.8). These results suggest that the barren land had relatively high and balanced nutrients, with the highest homogeneity among the four land-use types. The grassland had considerable improvement in all nutrients (especially SAP; 95.6% of the area had high SAP grades); however, its improvement was the most heterogeneous (S′ = 4.5, E′ = 0.7). As the second-most heterogeneous land-use type (S′ = 4.0, E′ = 0.8), the forestland had relatively low STN, SAP, and SAK levels due to high nutrient uptake and storage by tree species, but it had the highest proportion of area that reached high SOM grades (36.4%) and medium to high SOM grades (100.0%) due to its high community productivity. The cultivated land, which received fertilization for an additional three years, was the most imbalanced in terms of nutrients. It had the highest proportion of area that reached high SAP grades (98.0%); in contrast, its area proportions of low-grade SAK and SOM (69.0 and 32.9%, respectively) were the highest among the four land-use types. Based on the above comprehensive characterization of soil nutrient grade variation, guidance was given for fine management of reclaimed mined land and the optimization of reclamation measures.

The Human Impact on All Soil-Forming Factors during the Anthropocene

Soil-the thin outer skin of the Earth's land-is a critical and fragile natural resource. Soil is the basis for almost all global agriculture and the medium in which most terrestrial biological activity occurs. Here, we reconsider the five forming factors of soil originally suggested more than a century ago (parent material, time, climate, topography, and organisms) and updated over the years to add human activity as the sixth forming factor. We demonstrate how present anthropogenic activity has become the leading component influencing each one of the original forming factors. We thus propose that, starting from the Anthropocene, human activity should no longer be considered as a separate forming factor but rather a main driving force of each of the five original ones. We suggest that the importance of soil and the strong direct and indirect effects of anthropogenic factors on soil-forming factors should be considered together to ensure sustainability of this critical resource.

Climate Change Planning: Soil Carbon Regulating Ecosystem Services and Land Cover Change Analysis to Inform Disclosures for the State of Rhode Island, USA

The state of Rhode Island (RI) has established its greenhouse gas (GHG) emissions reduction goals, which require rapidly acquired and updatable science-based data to make these goals enforceable and effective. The combination of remote sensing and soil information data can estimate the past and model future GHG emissions because of conversion of “low disturbance” land covers (e.g., evergreen forest, hay/pasture) to “high disturbance” land covers (e.g., low-, medium-, and high-intensity developed land). These modeled future emissions can be used as a predevelopment potential GHG emissions information disclosure. This study demonstrates the rapid assessment of the value of regulating ecosystems services (ES) from soil organic carbon (SOC), soil inorganic carbon (SIC), and total soil carbon (TSC) stocks, based on the concept of the avoided social cost of carbon dioxide (CO2) emissions for RI by soil order and county using remote sensing and information from the State Soil Geographic (STATSGO) and Soil Survey Geographic Database (SSURGO) databases. Classified land cover data for 2001 and 2016 were downloaded from the Multi-Resolution Land Characteristics Consortium (MRLC) website. Obtained results provide accurate and quantitative spatio-temporal information about likely GHG emissions and show their patterns which are often associated with existing urban developments. These remote sensing tools could be used by the state of RI to both understand the nature of land cover change and likely GHG emissions from soil and to institute mandatory or voluntary predevelopment assessments and potential GHG emissions disclosures as a part of a climate mitigation policy.

Incorporating Ecosystem Services into STEM Education

The framework of ecosystem services (ES) and disservices (ED) has increasingly been used in various science, technology, engineering, and mathematics (STEM) disciplines, including soil science. The objectives of this study were to use ES/ED concepts to extend and test an existing lecture and laboratory exercise on soil organic carbon (SOC) in an online introductory soil science course (FNR 2040: Soil Information Systems) taught to Clemson University students from various STEM disciplines (forestry, wildlife biology, and environmental and natural resources) in Fall 2020. The laboratory exercise was extended with a series of reusable learning objects (RLOs), which are self-contained digital modules commonly utilized in e-learning. The laboratory exercise consisted of identifying ES and calculating the avoided social cost of carbon (SC-CO2) from soil organic carbon stocks in the assigned soil’s topsoil horizon. The laboratory exercise effectively increased student familiarity with ES/ED as indicated by the post-assessment survey with a +24.4% increase in the moderately familiar category and a +36.1% increase in the extremely familiar category. The graded online quiz consisted of ten questions and was taken by 51 students with an average score of 8.7 (out of 10). A post-assessment survey indicated that most of the students found that the laboratory was an effective way to learn about ES/ED with examples from soil science. Detailed students’ comments indicated enjoyment of learning (e.g., calculations, applying new knowledge), the value of multimedia (e.g., PowerPoint, video), the flexibility of learning (e.g., different parts in the laboratory), the applicability of content (e.g., real-world examples), and criticism (e.g., tedious calculations). A word cloud based on students’ comments about their experience with the laboratory exercise on soil ES indicated the most common words used by students to describe their experience, such as “soil services”, “learning”, “enjoyed”, and “ecosystems”, among others. Incorporating ES/ED into an undergraduate STEM course enabled students to connect ES/ED provided by soil with the societal systems reliant on the soil resources.

Soil Carbon Regulating Ecosystem Services in the State of South Carolina, USA

Sustainable management of soil carbon (C) at the state level requires valuation of soil C regulating ecosystem services (ES) and disservices (ED). The objective of this study was to assess the value of regulating ES from soil organic carbon (SOC), soil inorganic carbon (SIC), and total soil carbon (TSC) stocks, based on the concept of the avoided social cost of carbon dioxide (CO2) emissions for the state of South Carolina (SC) in the United States of America (U.S.A.) by soil order, soil depth (0–200 cm), region and county using information from the State Soil Geographic (STATSGO) database. The total estimated monetary mid-point value for TSC in the state of South Carolina was $124.36B (i.e., $124.36 billion U.S. dollars, where B = billion = 109), $107.14B for SOC, and $17.22B for SIC. Soil orders with the highest midpoint value for SOC were: Ultisols ($64.35B), Histosols ($11.22B), and Inceptisols ($10.31B). Soil orders with the highest midpoint value for SIC were: Inceptisols ($5.91B), Entisols ($5.53B), and Alfisols ($5.0B). Soil orders with the highest midpoint value for TSC were: Ultisols ($64.35B), Inceptisols ($16.22B), and Entisols ($14.65B). The regions with the highest midpoint SOC values were: Pee Dee ($34.24B), Low Country ($32.17B), and Midlands ($29.24B). The regions with the highest midpoint SIC values were: Low Country ($5.69B), Midlands ($5.55B), and Pee Dee ($4.67B). The regions with the highest midpoint TSC values were: Low Country ($37.86B), Pee Dee ($36.91B), and Midlands ($34.79B). The counties with the highest midpoint SOC values were Colleton ($5.44B), Horry ($5.37B), and Berkeley ($4.12B). The counties with the highest midpoint SIC values were Charleston ($1.46B), Georgetown ($852.81M, where M = million = 106), and Horry ($843.18M). The counties with the highest midpoint TSC values were Horry ($6.22B), Colleton ($6.02B), and Georgetown ($4.87B). Administrative areas (e.g., counties, regions) combined with pedodiversity concepts can provide useful information to design cost-efficient policies to manage soil carbon regulating ES at the state level.