Differentiation of Soil Fauna Populations in Conventional Tillage and No-Tillage Red Soil Ecosystems

In a field experiment, the populations of major soil fauna groups including earthworms, enchytraeids,arthropods and nematodes were examined in conventional tillage (CT) and no-tillage (NT) red soil ecosystems to evaluate their responses to tillage disturbance. Earthworms, macrry and micro-arthropods were stimulated under NT with earthworms showing the highest population increase by four times, while enchytraeids and nematodes favored CT system, predicting certain adaptability of these animals to plow-disturbed soil environment. On the basis of relative response index it was found that soil fauna was more sensitive to tillage than soil resource base (C and N pools) and microflora. The population structure of soil fauna was also affected by tillage treatments. Analysis on nematode trophic groups showed that bacteria-feeding and plant parasitic nematodes were more abundant in CT soil whereas the proportions of fungivores and omnivorepredators increased in NT soil. Possible reasons for the differentiation in both size and structure of the fauna population were discussed and the ecological significance involved in these changes was emphasized.

Preliminary Study on Biological Characteristics of Degraded Soil Ecosystems in Dry Hot Valley of the Jinsha River

Distribution characteristics of soil animals, microorganisms and enzymatic activity were studied in the dry red soil and Vertisol ecosystems with different degradation degrees in the Yuanmou dry hot valley of the Jinsha River, China. Results showed that Hymenoptera, Araneae and Collembola were the dominant groups of soil animals in the plots studied. The numbers of groups and individuals and density of soil animals in the dry red soil series were higher than those in the Vertisol series, and the numbers of individuals and density of soil animals decreased with the degree of soil degradation. Bacteria dominated microbiocoenosis not only in the dry red soils but also in the Vertisols. Microbial numbers of the dry red soil series were higher than those of Vertisol series, and decreased with the degree of soil degradation. The activities of catalase, invertase, urease and alkaline phosphatase declined with the degradation degree and showed a significant decline with depth in the profiles of both the dry red soils and the Vertisols, but activities of polyphenol oxidase and acid and neutral phosphatase showed the same tendencies only in the Vertisols. It was concluded that the characteristics of soil animals, microorganisms and enzymatic activity could be used as the bio-indicators to show the degradation degree of the dry red soils and Vertisols. Correlation among these soil bio-indicators was highly significant.

Contribution of Herbaceous Plants and Their Status and Role in Soil and Water Ecosystem

In this paper,the contemporary understanding process of herbaceous plants and their contributions are elaborated.The systematic idea of"mountain,river,forest,field,lake,and grass are a community of life"has led the grass to enter a new era of development.Broadly speaking,vegetation includes grassland,forest,crop,garden,etc.,while herbaceous vegetation is the most widely distributed on earth.From the macro and micro perspectives of soil and water ecology,this paper discusses the position and role of herbaceous vegetation in the earth's soil and water ecosystem,especially the fundamental position in mountain,river,forest,field,lake,grass and sand.Starting from the concept of soil and water ecology,the integrated protection and systematic management of mountain,river,forest,field,lake,grassland,and sand is proposed.Essentially,it is the protection and management of soil and water ecology,which summarizes various ecological systems on earth.The successful application of herbaceous plants in ecological restoration projects of mine has further enriched and developed the theory of soil and water ecology.

Changes in Ecosystem Service of Soil Conservation Between 2000 and 2010 and Its Driving Factors in Southwestern China

Human activities significantly alter ecosystems and their services; however, quantifying the impact of human activities on ecosystems has been a great challenge in ecosystem management. We used the Universal Soil Loss Equation and county-level socioeconomic data to assess the changes in the ecosystem service of soil conservation between 2000 and 2010, and to analyze its spatial characteristics and driving factors in the southwestern China. The results showed that cropland in the southwestern China decreased by 3.74%, while urban land, forest, and grassland areas increased by 46.78%, 0.86%, and 1.12%, respectively. The soil conservation increased by 1.88 × 10^(11) kg, with deterioration only in some local areas. The improved and the degraded areas accounted for 6.41% and 2.44% of the total land area, respectively. Implementation of the Sloping Land Conversion Program and urbanization explained 57.80% and 23.90% of the variation in the soil conservation change, respectively, and were found to be the main factors enhancing soil conservation. The 2008 Wenchuan earthquake was one of the factors that led to the degradation of soil conservation. Furthermore, industrial adjustment, by increasing shares of Industry and Service and reducing those of Agriculture, has also promoted soil conservation. Our results quantitatively showed and emphasized the contributions to soil conservation improvement made by implementing ecological restoration programs and promoting urbanization. Consequently, these results provide basic information to improve our understanding of the effects of ecological restoration programs, and help guide future sustainable urban development and regional industrial restructuring.

Coupling changes of soil functional gene abundances and extracellular enzyme activities across the diagnostic horizons of agricultural Isohumosols

Soil functional microbial taxa and extracellular enzymes are involved in a variety of biogeochemical cycling processes.Although many studies have revealed the vertical change patterns of microbial communities along soil profile,the general understanding of the coupling changes in the functional gene abundances(FGAs)and extracellular enzyme activities(EEAs)in soil profiles is still limited,which hinders us from revealing soil ecosystem processes.Herein,we comparatively investigated the FGAs and EEAs in the diagnostic A,B,and C horizons of soil profiles obtained from two suborders of Isohumosols(Mollisols),Ustic and Udic Isohumosols,in Northeast China based on quantitative real-time polymerase chain reaction and standard fluorometric techniques,respectively.The distribution patterns of both FGAs and EEAs significantly distinguished by the two soil suborders and were also separated from A to C horizon.Additionally,the variations of EEAs and FGAs were greater in Udic Isohumosols compared to Ustic Isohumosols along soil profiles,and greater changes were observed in C horizon than in A horizon.Both FGAs and EEAs correspondently decreased along the soil profiles.However,when normalized by soil organic carbon,the specific EEAs significantly increased in deep soil horizons,suggesting that microorganisms will input more resources to the production of enzymes to ensure microbial nutrient requirements under resource scarcity.More importantly,we revealed that soil microbial nutrient demands were limited by carbon(C)and phosphorus(P),and the C and P limitations significantly increased along soil profiles with a greater C limitation observed in Ustic Isohumosols than in Udic Isohumosols.Overall,our findings provided solid evidence showing the links between FGAs,EEAs,and microbial nutrient limitations,which would be helpful for a better understanding of the ecosystem processes in soil profiles.

Bacteriophages assisted bacteria to facilitate soil multifunctionality under organochlorine pesticide contamination

As the most abundant living entities in the environment,viruses have been well recognized as crucial members in sustaining biogeochemical cycling.However,the significance of viruses in soil ecosystem multifunctionality remains under-explored.In this study,we used metagenomics and meta-viromics analysis to investigate the role of soil viruses in soil ecosystem functions under heavy,light,and no organochlorine pesticides(OCPs)contamination.In the three types of soil samples collected,lightcontaminated soils supported the highest level of multifunctionality,followed by heavy-contaminated soils and clean soils.Additionally,our results revealed a positive correlation between bacterial community evenness and multifunctionality index(p<0.05).Dominant bacterial species with biodegradation and stress resistance advantages exhibited higher abundance in OCPaffected soils,potentially playing a core functional supporting role.Furthermore,our results indicated that the species richness and diversity of bacteriophages were positively correlated with multifunctionality(p<0.05)in OCP-affected soils.Bacteriophages in OCP-affected soils regulate host metabolism and enhance soil ecosystem multifunctionality by infecting functional bacterial hosts and encoding AMGs related to soil element cycling.Our findings emphasize the potential effect of phages on ecosystem multifunctionality in contaminated soil,suggesting that phages may serve as contributors to soil ecology beyond bacteria and other microorganisms.Therefore,in polluted or constrained soils,further research could potentially translate phage communities and related ecological processes into artificial methods for application in soil pollution remediation or ecological restoration.

Technical Innovation of Land Treatment Systems for Municipal Wastewater in Northeast China

On the basis of ecological principles including holistic optimization, cycling and regeneration, and regional differentiation, land treatment systems (LTSs) for municipal wastewater were continuously explored and updated in the western Shenyang area and the Huolinhe area, China. Intensified pretreatment, addition of a man-made soil filtration layer, and use of an ecologically diversified secondary plant cover were proved to be technically feasible. Hydraulic loading was determined according to the assimilation capacity of soil ecosystems, thus ensuring safe operation of wastewater treatment. This modernized and alternative approach to wastewater treatment had been widely applied in middle-sized and small cities and towns of Northeast China, and these innovative systems in some areas had indicated favorable ecological, social, and economic benefits.

Continental-scale assessment of provisioning soil functions in Europe

Introduction:A framework is developed to link major soil functions to ecosystem services assessment.Provisioning soil functions—with primary linkages to ecosystem services—are evaluated on a continental scale in Europe.Methods:We defined major provisioning soil functions combining the approaches proposed by the Millennium Ecosystem Assessment and the Thematic Strategy for Soil Protection of the European Union.Soil productivity was evaluated by three main land use types(cropland,grassland,forest)using a validated expert model called SoilProd.Models include soil,climate and topographic criteria.Raw material provision capacity of soils was assessed on the basis of(i)organic carbon content and(ii)availability of soil materials for construction.Results:A coherent system of soil function-based ecosystem services was compiled,taking into account major soil functions.We also produced new data on soil-based provisioning ecosystem services,including productivity and raw material availability.The attempts to cover the main human activities requiring materials of soil origin and to map the locations where those materials are available on a continental scale provide new insight to this field of research.Conclusions:Soil-based ecosystem services can be assessed by the evaluation of soil functions which play a role in the production of these services.Quantitative analysis and comparison of the spatial distribution of the investigated soil functions were performed.While crop productivity showed a general trend to increase in a northward and westward direction,local soil quality in most regions—except in the Mediterranean—can compensate for climatic handicaps to a great extent.Comparison of areas with potential for providing ecosystem services by individual soil functions highlights the complexity of decision-making for resource utilization but also the possibilities for optimization and more conscious management.

Soil Respiration of Biologically-Crusted Soils in Response to Simulated Precipitation Pulses in the Tengger Desert, Northern China

Soil respiration(SR) is a major process of carbon loss from dryland soils, and it is closely linked to precipitation which often occurs as a discrete episodic event. However, knowledge on the dynamic patterns of SR of biologically-crusted soils in response to precipitation pulses remains limited. In this study, we investigated CO_2 emissions from a moss-crusted soil(MCS) and a cyanobacterialichen-crusted soil(CLCS) after 2, 4, 8, 16, and 32 mm precipitation during the dry season in the Tengger Desert, northern China.Results showed that 2 h after precipitation, the SR rates of both MCS and CLCS increased up to 18-fold compared with those before rewetting, and then gradually declined to background levels; the decrease was faster at lower precipitation amount and slower at higher precipitation amount. The peak and average SR rates over the first 2 h in MCS increased with increasing precipitation amount, but did not vary in CLCS. Total CO_2 emission during the experiment(72 h) ranged from 1.35 to 5.67 g C m-2 in MCS, and from 1.11 to3.19 g Cm^(-2) in CLCS. Peak and average SR rates, as well as total carbon loss, were greater in MCS than in CLCS. Soil respiration rates of both MCS and CLCS were logarithmically correlated with gravimetric soil water content. Comparisons of SR among different precipitation events, together with the analysis of long-term precipitation data, suggest that small-size precipitation events have the potential for large short-term carbon losses, and that biological soil crusts might significantly contribute to soil CO_2 emission in the water-limited desert ecosystem.

Ecology of industrial pollution in China

Industrial development has brought China both opportunities and challenges since the reform and opening up in 1978.Spatial and temporal analysis showed that rapid industrialization has made eastern China under a more serious pollution stress.The most serious effects of industrial pollution were reflected in aquatic and soil ecosystem degradation,and damage can be observed from species,population,and community to ecosystem level.Public consciousness about contaminated sites rose from 2004 leading to greater efforts in ecological remediation,monitoring,and risk governance.Considerable efforts are still needed in expanding the extent and breadth of monitoring to explore where the greatest ecological risks lie and how to control them.Ecology of industrial pollution has become a popular discipline in China and will be further developed to help achieve the Sustainable Development Goals.Future research for a better ecological risk management should be focused on multi-media transfer and effects of mixed pollutants,mechanisms for clean energy and material flow,and integration of ecological risk with human health risk.

Ecotoxicological assessment of diffuse pollution using biomonitoring tool for sustainable land use in Thailand

As a developing country, Thailand has a significant issue with diffuse pollution of the soil ecosystem due to an indiscriminate use of agrichemicals and poorly regulated disposal of a wide variety of hazardous wastes. Practical risk assessment tools based on locallyoccurring species are needed to assess the effects of diffuse pollutants on the soil ecosystem in Thailand because reliance on soil criteria developed for overseas conditions may provide inadequate protection. Native soil organisms in Thailand may be more or less sensitive to contaminants compared to overseas test species. This article described a biological indicator approach for ecological risk assessment of diffuse pollution in the soil ecosystem of Thailand from pesticide application with the aim of developing standardized protocols using native species and locally generated data to better evaluate the ecological risks of non-point source soil pollution. It was found that ecotoxicological assessment provided a better understanding of the ecological impacts that diffuse pollution induced on Thai environmental conditions. Thai soil biota species were more sensitive to soil contaminants than similar species overseas. Soil series also had an influence on the ecotoxicology of contaminants to soil biota. Collembolan, Cyphoderus sp., was demonstrated as a useful alternative test species to Folsomia candida （international test species） for terrestrial ecotoxicological testing of Thai soils. In addition, the soil biota activities such as soil respiration and earthworm avoidance including soil biodiversity and the litter bag decomposition technique are also good tools to assess the effects of diffuse pollution by pesticides on the soil ecosystem of Thailand.

HARNESSING ECOLOGICAL PRINCIPLES AND PHYSIOLOGIC MECHANISMS IN DIVERSIFYING AGRICULTURAL SYSTEMS FOR SUSTAINABILITY:EXPERIENCE FROM STUDIES DEPLOYING NATUR-EBASED SOLUTIONS IN SCOTLAND

To achieve the triple challenge of food security,reversing biodiversity declines plus mitigating and adapting to climate change,there is a drive to embed ecological principles into agricultural,value-chain practices and decisionmaking.By diversifying cropping systems at several scales there is potential to decrease reliance on inputs,provide resilience to abiotic and biotic stress,enhance plant,microbe and animal biodiversity,and mitigate against climate change.In this review we highlight the research performed in Scotland over the past 5 years into the impact of the use of ecological principles in agriculture on sustainability,resilience and provision of ecosystem functions.We demonstrate that diversification of the system can enhance ecosystem functions.Soil and plant management interventions,including nature-based solutions,can also enhance soil quality and utilization of legacy nutrients.Additionally,this is facilitated by greater reliance on soil biological processes and trophic interactions.We highlight the example of intercropping with legumes to deliver sustainability through ecological principles and use legumes as an exemplar of the innovation.We conclude that there are many effective interventions that can be made to deliver resilient,sustainable,and diverse agroecosystems for crop and food production,and these may be applicable in any agroecosystem.