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Trade-offs between soil functions hamper maximizing soil multifunctionality in agroecosystems. Taking soil microbial functional trade-offs into consideration in agricultural management is crucial for optimizing the impacts of changes in soil microbial communities on soil health in agroecosystems. Interactions within soil microbial communities influence functional trade-offs. Manipulating soil microbial diversity and interactions through soil health-improving management can alleviate functional trade-offs and improve soil health and agricultural sustainability. Better mechanistic understanding of the interdependencies between soil-induced functions is essential to improve soil health and agricultural sustainability. Soil microbial communities play pivotal roles in maintaining soil health in agroecosystems. However, how the delivery of multiple microbial functions in agroecosystems is maintained remains poorly understood. This may put us at risk of incurring unexpected trade-offs between soil functions. We elucidate how interactions between soil microbes can lead to trade-offs in the functioning of agricultural soils. Interactions within soil microbial communities can result in not only positive but also neutral and negative relationships among soil functions. Altering soil conditions through soil health-improving agricultural management can alleviate these functional trade-offs by promoting the diversity and interrelationships of soil microbes, which can help to achieve more productive and sustainable agroecosystems. [ABSTRACT FROM AUTHOR]

Double rice cropping system are crucial for sustainable food and security and agricultural ecosystem balance in South China. However, intensive chemical fertilization has reduced rice productivity, and soil and ecosystem degradation. To develop a suitable organic fertilization scheme for double-rice cropping systems and explain its association with soil quality index (SQI), microbial diversity and ecological multifunctionality (EMF). A 4-years field trial was conducted to examine the effects of four different organic materials (bio-organic fertilizer, OF; decomposed straw and manure, ST; biochar, BC and soil conditioner as silicon calcium magnesium fertilizer, SC) combined with chemical fertilizers (NPK) on rice yield, soil microbial abundance and diversity, SQI and EMF. Compared with NPK, NPK.OF and NPK.ST in early rice, and NPK.OF and NPK.BC in late rice both resulted in higher rice yield and SQI by enhancing soil microbes, soil dissolved organic carbon (DOC), and carbon (C)- and nitrogen (N)-cycle enzyme activities. Additionally, optimum organic fertilization increased soil bacterial abundance in early rice and that of fungi in late rice. Proteobacteria , Acidobacteriota , Bacteroidota and Nitrospirota were the dominant microbial groups in both rice seasons. Specifically, NPK.OF and NPK.ST increased the abundance of Bacteroidetes and Proteobacteria , but suppressed that of Acidobacteria and Nitrosospira in early rice. Conversely, the fungal community showed no significant changes with organic fertilization in late rice. Microbial phylogenetic diversity (PD) of bacteria and fungi showed positive linear relationships with soil EMF in both rice seasons. Heatmap analysis indicated that Proteobacteria and Nitrospirae can serve as bioindicators of soil EMF in response to organic fertilization in early rice. This was related to the soil indices of bacterial PD, and DOC. Random forest and structural equation model analyses revealed that soil bacterial PD, DOC, and N-functional enzymes were the primary drivers and predictors of EMF. Soil bacterial diversity and its interactions with soil properties played an important role in determining rice productivity and EMF. Suitable fertilization management in the region include NPK.OF and NPK.ST for early rice, and NPK.OF and NPK.BC for late rice. Optimum organic fertilization can achieve higher rice yield, SQI, and EMF in a double rice cropping system. However, future widespread application requires careful overall consideration of environmental factors, soil fertility and rice species in different ecological regions. • Optimum organic fertilization enhances rice yield, microbial diversity and EMF. • Optimum organic fertilization boosts bacterial abundance and diversity in early rice but fungi abundance in late rice. • Proteobacteria and Nitrospirae serve as EMF bioindicators responded to organic fertilization in early rice. • Bacterial PD, DOC, and N-functional enzymes serve as the main drivers of soil EMF. [ABSTRACT FROM AUTHOR]

Subsurface manure application has been suggested as a priming strategy to improve soil fertility and potentially enhance crop yield quickly. However, the soil quality and ecosystem multifunctionality responses and their relationship with crop yield remain uncertain. Here, a two-year field experiment was conducted to investigate the effects of different subsurface manure application methods (1T, one-time fertilization; and 2T, two-time split fertilization during two consecutive years) with the same manure amount on soil quality index (SQI), ecosystem multifunctionality (EMF), and crop yield in the North China Plain. Compared to control (no manure application, CK), 1T increased SQI at both 0–20 and 20–40 cm soil layers by 15–19 % in the first year, but no change in the second year. As a comparison, 2T increased SQI at 0–20 and 20–40 cm soils by 37–42 % compared to CK in the second year. Meanwhile, 2T increased soil EMF at 0–20 cm (0.4 unit) compared to CK over the two years. Both 1T and 2T increased soil EMF at 20–40 cm (0.1–0.8 unit) over the two years. The crop yield was positively related to surface SQI and subsurface EMF regardless of manure application method. Soil organic C, total C, total N, total P, and the C and P cycling-related enzyme activities were key factors that contributed to the improvement of SQI and EMF. The partial least squares path models revealed that the two subsurface manure application methods enhanced surface SQI and subsurface EMF by improving topsoil nutrients and subsoil enzyme activities separately, consequently increasing crop yield. Overall, our results documented that subsurface manure application is an effective strategy for improving soil quality and crop yield. [Display omitted] • The effects of two subsurface manure application methods were explored in the North China Plain. • One-time application increased soil ecosystem multifunctionality compared to control at 20–40 cm. • Two-time split application enhanced soil quality index and ecosystem multifunctionality at 0–20 cm and 20–40 cm. • The improved topsoil quality and subsoil multifunctionality contributed to increased winter wheat yield. [ABSTRACT FROM AUTHOR]

Soil microbial communities play a crucial role in driving multiple ecosystem functions. Although numerous studies have investigated the effects of fertilization on the entire soil microbial community, the responses of abundant (relative abundance ≥ 1 % in all samples, or ≥ 1 % in some samples but never < 0.01 % in any samples) and rare (relative abundance < 0.01% in all samples, or < 0.01% in some samples but never≥ 1% in any samples) microbial taxa, as along with their relative contributions to ecosystem functions in agricultural soils under combined organic and inorganic fertilization, have been less explored. Here, a field experiment revealed that rare bacterial and fungal taxa were more sensitive to short-term fertilization than abundant taxa. The combined application of inorganic and organic fertilizers maintained the alpha-diversity of rare bacterial taxa and enhanced the alpha-diversity of rare fungal taxa. The significant impact of fertilization on the bacterial community was primarily induced by alterations in soil pH (decreased from 6.01 to 5.46), total phosphorus (0.32 – 0.37 g/kg), available phosphorus (1.24 – 4.76 mg/kg), and available potassium (41.11 – 58.78 mg/kg), whereas the fungal community was less influenced by fertilization. The dissimilarity of both abundant (Mantel r = 0.38, P = 0.001) and rare (Mantel r = 0.26, P = 0.014) bacterial taxa exhibited positive relationships with ecosystem multifunctionality. Additionally, ecosystem multifunctionality was positively associated with the relative abundance of specific genera and keystone species, particularly rare bacterial taxa (e.g., Melioribacter , Aquisphaera , Sunxiuqinia , Methylobacterium , and Thermosporothrix), the abundant fungal genus Achroiostachys , and rare fungal taxa (e.g., Paraphelidium , Pseudallescheria , Scutellinia , Niesslia , Tilletia , Coprinopsis , Poaceascoma , Entrophospora sp., Acremonium persicinum , Hydropisphaera erubescens , and Rozellomycota sp.) (ρ = 0.52–0.75, P < 0.05). A partial least-squares path model indicated that soil nutrients (path coefficient = 0.83, p = 0.001) and microbial beta-diversity (path coefficient = 0.18, p = 0.049) exerted primary direct and positive effects on ecosystem multifunctionality, with soil nutrients also indirectly influencing ecosystem multifunctionality through microbial beta-diversity. Collectively, these findings underscore the significant response of rare, rather than abundant, microbial taxa and their contributions to ecosystem multifunctionality. This highlights the potential of appropriately combined inorganic and organic fertilizers, which promote rare microbial taxa, to enhance the multifunctionality of agricultural ecosystems. • Combined inorganic and organic fertilization enhanced ecosystem multifunctionality. • Rare microbial taxa had stronger responses to fertilization than the abundant taxa. • Combined inorganic and organic fertilization boosted rare microbial α-diversity. • Short-term fertilization altered bacterial, but not fungal, community structures. • Rare microbes have an oversized role in enhancing ecosystem multifunctionality. [ABSTRACT FROM AUTHOR]

Despite the importance of soil bacterial diversity in regulating ecosystem functions and services is increasingly recognized, it is still unclear how the relationships of bacterial diversity-ecosystem multifunctionality changes in spatial pattern. Here, combining spatial analysis methods of GIS and geostatistics analysis with bacterial community, based on the differences in the dominant forest types (Quercus aliena var. acuteserrata , Pinus armandi and Soft-broad mix) in the Qinling Mountains, we revealed the spatial distribution patterns of bacterial composition and diversity, and forest ecosystem multifunctionality. Moreover, the spatial variations the relationships of bacterial diversity-multifunctionality were evaluated. Our findings indicated bacterial diversity and multifunctionality in three forests exhibited a similar pattern, with Quercus aliena var. acuteserrata forest > Soft-broad mix forest > Pinus armandi forest. Form spatial perspective, bacterial diversity was higher in the southern region, followed by northeast. Forest ecosystem multifunctionality decreased from the southwest to the northeast. We also observed direct positive effects of bacterial diversity and dominant taxa on forest multifunctionality. The relationship of bacteria-multifunctionality exhibited significant spatial variations, a positive correlation remained predominant in spatial dimension. Overall, this study highlights the changing characteristics of the connections between bacteria and forest multifunctionality under the regulation of vegetation, climate, geographical features and their interactions. The application of geospatial analysis methods to microorganism-ecosystem function offered valuable insights for predicting microbial spatial distribution and protecting forest ecosystems. [Display omitted] • The spatial patterns of bacteria community diversity were revealed. • Bacterial diversity and dominant taxa positive effect on multifunctionality. • The relationships of bacteria-multifunctionality exhibited significant spatial variations. • A positive correlation remained predominant in spatial dimension. [ABSTRACT FROM AUTHOR]

Semi-natural grasslands and their diverse biota are threatened by changes in land-use like afforestation, abandonment of traditional practices, urban development or conversion into intensive agricultural land. Extensive loss and fragmentation of semi-natural grasslands consequently affects ecosystem functioning inherit to open landscapes and the sustainable provision of ecosystem services. Ecological restoration of grasslands has potential to halt further decline and hopefully reverse some of the damage done to the grasslands and vital ecosystem services they provide. By assessing grasslands before and after the restoration, we evaluated how restoring overgrown and forested semi-natural grasslands to open grasslands impacts nine ecosystem services: habitat maintenance, soil condition maintenance, soil carbon storage, pollination, pest regulation, provision of wild food and medicinal herbs, forage production, wood production and recreation. We also analyzed the relationship between ecosystem multifunctionality and species richness of multiple organism groups. We found that already few years after restoration, restored grasslands exhibited rapidly increasing biodiversity and ecosystem service provision. Similarly, the overall ecosystem multifunctionality increased significantly after restoration in previously overgrown and afforested grasslands. However, while a robust and strong positive relationship between multitrophic diversity and ecosystem multifunctionality existed before restoration, this relationship was somewhat weakened after restoration. We propose two potential explanations: first, the previously distinct condition classes became more similar, starting to resemble open grassland habitats in their species richness and composition. Second, the relationship may have been weakened by the temporarily disrupted and transitional nature of the ecosystem post-restoration, due to varying recovery rates among different species groups and ecosystem services. Notably, soil-related services (carbon storage and soil maintenance) take longer to respond to restoration, compared to other services. In addition, we detected significant negative impact of prolonged drought on pest regulation and forage production service in both restored and unrestored areas. Semi-natural grasslands are both biodiversity and ecosystem service "hotspots" in European landscapes and restoring these habitats significantly increases the provision potential of important ecosystem services. However, restoration planning must consider landscape history, regional characteristics and the importance of long-term monitoring for getting the most accurate results. • Grassland restoration raised multitrophic diversity and ecosystem multifunctionality. • We detected rapid positive impacts of restoration on several ecosystem services. • No effect on soil condition or soil carbon storage was detected. • Prolonged drought severely impacts ecosystem service provision and grassland recovery. • Long-term monitoring of the sites is essential to measure restoration success and grassland recovery. [ABSTRACT FROM AUTHOR]

Ecosystem multifunctionality reflects the capacity of ecosystems to simultaneously maintain multiple functions which are essential bases for human sustainable development. Whereas viruses are a major component of the soil microbiome that drive ecosystem functions across biomes, the relationships between soil viral diversity and ecosystem multifunctionality remain under-studied. To address this critical knowledge gap, we employed a combination of amplicon and metagenomic sequencing to assess prokaryotic, fungal and viral diversity, and to link viruses to putative hosts. We described the features of viruses and their potential hosts in 154 soil samples from 29 farmlands and 25 forests distributed across China. Although 4,460 and 5,207 viral populations (vOTUs) were found in the farmlands and forests respectively, the diversity of specific vOTUs rather than overall soil viral diversity was positively correlated with ecosystem multifunctionality in both ecosystem types. Furthermore, the diversity of these keystone vOTUs, despite being 10–100 times lower than prokaryotic or fungal diversity, was a better predictor of ecosystem multifunctionality and more strongly associated with the relative abundances of prokaryotic genes related to soil nutrient cycling. Gemmatimonadota and Actinobacteria dominated the host community of soil keystone viruses in the farmlands and forests respectively, but were either absent or showed a significantly lower relative abundance in that of soil non-keystone viruses. These findings provide novel insights into the regulators of ecosystem multifunctionality and have important implications for the management of ecosystem functioning. [ABSTRACT FROM AUTHOR]

• Structural attributes are the optimal predictors of ecosystem multifunctionality. • High plant diversity is critical for multifunctionality at low thresholds. • Increased soil fungal diversity promotes multifunctionality, bacteria show opposite trend. • Nutrient-rich soils have an enabling effect on forest multifunctionality. • Topography induces tradeoffs limiting synchronization optimizing diverse functions. Biodiversity is widely recognized as a crucial factor in driving ecosystem functioning. However, the processes that sustain forest ecosystem multifunctionality (EMF) through plant and soil microbial diversity are not yet fully understood. Here, we assessed eight ecosystem functions in a mixed temperate forest using averaging and weighted threshold methods to examine the associations between EMF and diversity across environmental gradients. The findings indicated that structural attributes serve as the optimal predictor of EMF. Both complementarity and selection effects had minor impacts on EMF, while the jack-of-all-trades effect drove the relationship between plant diversity and EMF. EMF was positively correlated with soil fungal diversity but negatively correlated with soil bacterial diversity. Soil microbial diversity influenced forest EMF by regulating the trade-offs between different functions. Additionally, we noted that forests situated on steep slopes may experience limitations in terms of multifunctionality, while nutrient-rich soils had a facilitative effect. This study underscores the significance of taking into account both aboveground and belowground diversity to improve forest functions. Within a certain range, more complex and diverse stand structures are effective strategies for sustainable forest management. [ABSTRACT FROM AUTHOR]

Soil biota and energy flow within their food webs have a profound impact on various ecosystem functions. However, there are still significant gaps in our understanding of how climate change factors, such as nitrogen deposition and reduced precipitation, impact ecosystem functioning, particularly in temperate forest ecosystems. In this study, we evaluated the response of ecosystems to long-term nitrogen deposition and/or reduced precipitation due to climate change. We assessed these responses by examining nematode community energy fluxes and their associated ecosystem multifunctionality. Field experiments were conducted in a temperate forest to simulate nitrogen deposition (5.0 kg N·ha−1·yr−1) using NH 4 NO 3 application and to reduce precipitation (to 70 % of a normal year) using rain shelters. Our findings showed that nitrogen addition and/or precipitation reduction treatments altered soil nematode composition. Nitrogen addition alone reduced the abundance and energy fluxes of high trophic groups such as omnivore-predators, which served as proxies for total abundance and energy fluxes. In contrast, precipitation reduction did not exhibit significant effects on overall abundance and energy fluxes. Environmental factors influencing changes in soil nematode abundance and energy fluxes included soil pH, NH 4 +-N, and total nitrogen in the soil. Nitrogen addition increased ecosystem multifunctionality by promoting nutrient cycling, while precipitation reduction promoted plant productivity and inhibited carbon cycling, without changing ecosystem multifunctionality. Regression analysis showed that soil nematode energy fluxes were negatively correlated with ecosystem multifunctionality. The effects of these two factors on soil nematode food webs showed temporal variation, as well as indicators related to multiple functions of the ecosystem. Our study suggests that soil nematode energy fluxes are more sensitive than nematode abundance for quantifying the relationship between biodiversity and ecosystem multifunctionality. [Display omitted] • N addition and/or precipitation reduction change the composition of soil nematode communities. • N addition decreases the abundance and energy fluxes of soil nematode communities. • Soil pH, NH 4 +, and total N played important roles in driving the nematode abundance and energy fluxes. • Interaction of N and water mediate ecosystem multifunctionality by changing soil nematode abundance and trophic energy flux. [ABSTRACT FROM AUTHOR]

How to determine the optimal dosage of phosphorus (P) fertilizer input for an agricultural field is important to maintain soil quality and crop production while minimizing environmental impact. In this study, we set up a 5-year rice-wheat rotation with contrasting P fertilization treatments (0, 25, 50, 75, 100, and 150 kg P 2 O 5 ha−1, hereafter, P 0 , P 25 , P 50 , P 75 , P 100 , and P 150 , respectively) per season to explore the relationship between the amount of P input and crop yield, P use efficiency (PUE), balance of P accumulation and loss, ecosystem multifunctionality (EMF), and soil quality. Our results indicate that increased P amounts significantly boosted rice and wheat production of both straw and grain, but the tendency slowed down when the input was over 75 kg P 2 O 5 ha−1. The PUE declined with increased P input and soil P balance of 50 kg P 2 O 5 ha−1 for wheat and 100 kg P 2 O 5 ha−1 for rice. Runoff emerges as the main pathway for soil P loss and escalates with higher P application rates. We emphasize increasing ridge height and controlling water input for basal fertilizer to minimize P loss. The application of P fertilizer increased the soil P pool, with labile P (L-P) and moderately labile P (M-P) increasing by 13–114 % and 23–111 %, respectively, compared to P 0. The transformation of M-P to L-P in paddy soil is associated with an increased abundance of Actinobacteria. Low P applications (P 25 and P 50) increased EMF by 3.27 and 3.58 times, while high P applications (P 75 , P 100 , and P 150) decreased EMF. Furthermore, P application significantly improved the soil quality index (SQI) compared to P 0. The impact of abiotic factors on yield and P loss is more significant than that of biotic elements, with the SQI serving as a dependable indicator for predicting yield. Central to minimizing P loss while maximizing yield is the reduction of Resin-P content and the maintenance of NaOH-P i levels, suggesting that organic materials may be a good alternative strategy. These findings provide valuable data and theoretical support for optimizing P application in rice-wheat cropping systems, promoting a mutually beneficial scenario for agricultural production and ecological protection. [Display omitted] • Balance P annually with 100 and 50 kg P 2 O 5 ha−1 in rice and wheat seasons. • Control runoff and prolong retention time in the field to minimize P loss. • The soil quality index (SQI) is a reliable predictor of crop yield. • Reduce Resin-P and maintain NaOH-P i to enhance SQI and decrease P loss. [ABSTRACT FROM AUTHOR]

Substituting chemical fertilizer with organic alternatives has been proven to improve soil fertility and crop yield and mitigate adverse environmental effects. However, the impact of different organic materials, such as animal-sourced organic fertilizer (AOF) and plant-sourced organic fertilizer (POF), on soil quality index (SQI) and ecosystem multifunctionality (EMF) in perennial systems like tea plantations remains unclear. This study evaluated the impact of partially substituting (30 %) chemical fertilizer with AOF (SM, sheep manure; PM, pig manure; CM, cow manure) and POF (SC, soybean cake) on soil properties, enzyme activity, enzyme stoichiometry, SQI, and EMF in a tea plantation of China. Partial substitution with AOF improved soil pH, total C content, and β-1,4-glucosidase, β-1,4-N-acetylglucosaminidase, L-leucine aminopeptidase, and acid phosphatase activities. In contrast, chemical fertilizer alone (CF) and POF substitution reduced these parameters. Compared with the control, CF, and POF, AOF substitution treatments effectively alleviated soil microbial C limitation but increased N limitation. Additionally, all fertilizer treatments enhanced the SQI and EMF of the tea plantation. Among the organic treatments, partial substitution with AOF resulted in the maximum increase in SQI (60 %–134 %) and EMF (157 %–177 %) compared with no fertilization, while POF substitution resulted in a comparatively lower improvement (53 % in SQI and 50 % in EMF). Random forest modeling identified five soil variables and eight enzyme variables as key contributors to the differences in EMF under partial organic substitution. Partial least squares path modeling further revealed that the changes in enzyme properties and microbial metabolic limitations directly influenced EMF in these treatments. Thus, the study proves that partially substituting chemical fertilizers with organic fertilizers, especially composted manure, enhances the soil quality and ecosystem functionality of tea plantations. These findings provide a scientific basis for developing effective soil management strategies to improve crop production sustainably. [Display omitted] • Organic fertilizer substitution improves soil quality index (SQI). and ecosystem multifunctionality (EMF) in a tea plantation. • Animal-sourced organic fertilizer (AOF) has a better effect on SQI and EMF than plant-sourced ones. • Partial AOF substitution alleviates microbial limitation but aggravates N limitation. • Soil properties indirectly affect EMF by altering soil enzyme properties. [ABSTRACT FROM AUTHOR]

Soil nematodes play a crucial role in maintaining agroecosystem functions and are sensitive to fluctuations in precipitation. However, the impact of soil nematode biodiversity on regulating agroecosystem multifunctionality under altered precipitation remains poorly understood. This study conducted a field experiment in a dryland agroecosystem in China's loess tableland region, manipulating precipitation levels (ambient, 1/3 decreased, and 1/3 increased) with and without nematode inhibitor application (10 % fosthiazate granules). The effects of altered precipitation on agroecosystem multifunctionality and the role of soil nematode biodiversity were explored. Seventeen variables related to crop productivity, nutrient supply, organic carbon decomposition, and pathogen control were investigated during wheat harvest period to assess agroecosystem multifunctionality. Soil nematode communities were analyzed using high-throughput sequencing targeting V4 region of 18 S rDNA, examing multiple dimensions of nematode biodiversity, such as taxonomic, functional, and phylogenetic diversity, and network complexity. Results indicated that increased precipitation positively influenced agroecosystem multifunctionality (rising from −0.02–0.29), driven by improved pathogen control, organic carbon decomposition and crop productivity functions, despite a decline in nutrient supply function. Concurrently, increased precipitation led to higher taxonomic, functional, and phylogenetic diversity, and network complexity of soil nematodes. This was evidenced by simultaneous rises in metrics such as Chao1, PD_whole_tree, functional divergence, multidimensional diversity, as well as node and edge numbers, betweenness centrality, and clustering coefficient within nematode networks. A positive correlation was observed between nematode multidimenstional diversity and agroecosystem multifunctionality (R2=0.072, P < 0.05). Further analysis revealed that higher precipitation levels enriched nematode diversity by improving soil water content, consequently amplifying nematode network complexity and ultimately enhancing agroecosystem multifunctionality. However, nematode inhibitor application substantially reduced nematode abundance across precipitation levels (reducing by 26.25 %-69.63 %), and decreased multidimensional nematode diversity under increased precipitation (decreasing from 0.34 to −0.15), thereby counteracting the multifunctionality benefits of precipitation. These findings underscore the significance of soil nematode biodiversity in enhancing agroecosystem multifunctionality under altered precipitation, offering guidance for sustainable agroecosystem management in the Loess Plateau and comparable environments impacted by climate change. [Display omitted] • Agroecosystem multifunctionality increases with increasing precipitation. • Increased precipitation positively impacts soil nematode biodiversity across multiple dimensions. • Greater nematode diversity and network complexity enhance agroecosystem multifunctionality. • Nematode biodiversity is crucial in driving agroecosystem multifunctionality under altered precipitation. [ABSTRACT FROM AUTHOR]

Soil ecosystem multifunctionality (EMF), the ability of an ecosystem to perform multiple functions, remains uncertain in its contribution to crop production, especially in the context of long-term fertilization ecosystems. This study was carried out on a 40-year-old long-term fertilization experiment in black soil in China. Soil samples were collected from four treatments: control (CK); nitrogen (N) fertilizer; phosphorus (P) fertilizer; and a combination of nitrogen and phosphorus (NP) in both maize and wheat planting seasons. The results showed significant effects of N, P fertilizers and crop season on soil biotic and abiotic properties, especially on soil enzyme activities. Crop productivity and soil EMF showed a similar pattern across different treatments and both crop seasons, with significant higher values recorded in treatments with N addition (i.e. N and NP). Soil EMF was strongly associated with crop productivity in both maize and wheat seasons, while soil pH had a negative impact on crop yield. Random forest analysis revealed that microbial functional gene structure was significantly correlated with both soil ecosystem multifunctionality and crop yield. This suggested that fertilization leads to alterations in soil nutrients and the composition of functional microbial communities, subsequently impacting ecological functions and crop growth. These findings indicated that mineral fertilizers can enhance crop yield through soil EMF in the black soils, while exerted substantial impact on soil properties, raising concerns about the sustainability of soils under continuous chemical fertilization. • Long-term mineral fertilization improves soil ecosystem multifunctionality. • Soil ecosystem multifunctionality is strongly associated with crop productivity. • Soil pH and nitrate were the dominant variables in determining soil ecosystem multifunctionality. • Functional gene community structure had significant correlation with crop production. [ABSTRACT FROM AUTHOR]

As a globally important alpine ecological zone, the Qinghai-Tibetan Plateau and the stability of its ecosystem are of substantial significance to the East Asian and global climates. Livestock grazing is a traditional and important method to use grassland resources and has influenced the structure and functions of alpine grassland ecosystems; therefore, a rational grazing management strategy is important for the stability of the structure and functioning of alpine grassland. In this study, we conducted a manipulated grazing experiment with yak and Tibetan sheep, which are indigenous livestock, to investigate the effects of livestock type and its mixing ratio on soil properties, functional traits of plants, and ecosystem multifunctionality (EMF) in alpine grassland. The results showed that (1) the livestock assembly regulated EMF of alpine grassland by changing the vegetation functional traits and soil physicochemical properties; (2) all grazing treatments increased EMF of alpine grassland, with Tibetan sheep single grazing and mixed with 1:6 yak to Tibetan sheep being significantly higher than no grazing; (3) and grazing achieved EMF regulation based on the indirect effects of community functional dispersion and soil quality index. Our results demonstrate that soil quality improvement due to livestock activities is more conducive to enhancing the ecosystem multifunctionality of alpine grassland vegetation than that under moderate grazing intensity, and Tibetan sheep are more conducive to improving and optimising the ecosystem multifunctionality of alpine grassland compared with yaks under moderate grazing intensity. • Yak/Tibetan sheep single- and mixed-grazing effects explored in alpine grassland. • Livestock assemblies regulated alpine grassland ecosystem multifunctionality (EMF). • Grazing achieved EMF regulation based on the indirect effects of community functional dispersion (FD is) and soil quality index (SQI). • The effect of Tibetan sheep was more significant than that of yaks. [ABSTRACT FROM AUTHOR]

• We present a framework for identifying the optimal landscape configuration for multifunctionality. • The optimal configuration can be predicted from the response of individual services to local and landscape factors. • We show that services sharing the same optimal landscape configuration strategy form management bundles. Increased pressure on land resources to provide multiple benefits calls for landscape strategies that optimize the supply of multiple ecosystem services (ES). Previous research into the drivers of landscape multifunctionality have focused on land use composition changes, but the spatial configuration of different land use types also drives ES supply. While the impact of landscape configuration on individual ES is well understood, the net outcome of these influences when considering many ES is not. Here we present the net-balance spatial interactions hypothesis, which posits that the strength and direction of local and surrounding landscape influences on the local supply of an individual ES will drive its optimal landscape configuration. Accordingly, the net balance of these influences across multiple prioritized ES will determine the optimal configuration for landscape multifunctionality. Further, ES that share the same optimal configuration strategy form a bundle that can be managed together. Using data from German grasslands we demonstrate that the net-balance spatial interactions hypothesis is applicable to land-use planning scenarios that aim to maximize multiple ES. It allows general rules to be applied when local, detailed ES data is not available, and can help identify the best option to minimize trade-offs in the face of multiple competing land-use objectives. [ABSTRACT FROM AUTHOR]

Rice-rice-oilseed rape rotation is a typical triple cropping system in Asia, and the development of rice-oilseed rape rotation plays an important role in ensuring global food and oil security. With the intensive cropping rotation and frequent changes between paddy and upland farming under anaerobic and aerobic conditions, whether tillage and straw return would be benefit for both agronomic and environmental perspectives remained to be tested. Therefore, we used a long-term locational experiment (15 years) employing four treatments of conventional tillage without straw incorporation (CT); conventional tillage with straw incorporation (CTS); no-tillage without straw mulching (NT); no-tillage with straw mulching (NTS), to assess the relationships among soil quality, ecosystem multifunctionality, and crop yields under the straw-returning and tillage strategies, based on both agronomic and environmental perspectives. The results showed that long-term straw return to the field could increase the yield of early rice by 6.24–8.80%, late rice by 3.81–7.13%, and oilseed rape by 9.55–14.45%. Long-term straw return enhanced soil quality index (SQI) by 22.21–40.74% and ecosystem multifunctionality (EMF) by 104.19–141.14% in the 0–20 cm soil layer. Long-term conventional tillage (i.e., CT and CTS) showed higher SQI and EMF values especially in the oilseed rape season. Structural equation modelling (SEM) indicated that straw return and tillage mainly increased crop yield by increasing the SQI in the oilseed rape season. In conclusion, long-term straw return with conventional tillage would be more benefit for the improvement of soil quality and the multifunctionality of soil ecosystems under triple paddy-upland rotation system, offering an effective approach for sustainable soil management and crop production. • Long-term straw return with tillage increased rice and oilseed rape yields. • Continuous straw return improves SQI by increasing soil physicochemical properties. • Straw-returned EMF is highly correlated with SQI under different tillage practices. • The oilseed rape season improves crop yield mainly by affecting soil quality. • In rice season, crop yields were increased directly through straw return. [ABSTRACT FROM AUTHOR]

Grassland biodiversity is vital for the provision of multiple ecosystem functions, termed ecosystem multifunctionality. As an effective practice of grassland management, grazing exclusion is widely used to restore the ecosystem multifunctionality of degraded grasslands, but it might not be always beneficial for conserving grassland biodiversity. Moreover, when grazing is excluded, it remains unknown whether grassland biodiversity promotes multifunctionality. Here, we conducted a field experiment of grazing exclusion along a gradient of climatic aridity across four major grassland types in the arid grasslands of northern China. We determined the effects of grazing exclusion on biodiversity and multifunctionality, and further investigated how grazing exclusion could modify biodiversity-multifunctionality relationships. We found that grazing exclusion increased soil fungal diversity, but had negligible effects on plant species richness and soil bacterial diversity. The effects of grazing exclusion on multifunctionality varied among grassland types: it promoted multifunctionality only in less arid grasslands. Importantly, multifunctionality was positively associated with plant species richness under grazing, but this positive association disappeared under grazing exclusion. In addition, we showed that climatic aridity affected multifunctionality indirectly through its negative effect on plant species richness under grazing, whereas such effect disappeared under grazing exclusion. Furthermore, aridity weakly reduced multifunctionality under grazing, and its negative effect was strengthened under grazing exclusion. Our results suggest that grazing exclusion restrains the capacity of plant biodiversity to sustain multiple ecosystem functions, and moreover, aggravates the negative influences of climatic dryness on ecosystem multifunctionality. Our findings illustrate the value of grazing for maintaining biodiversity-multifunctionality relationships and for mitigating the impacts of climate change in arid grasslands. • Grazing exclusion increases soil fungal diversity in the arid grasslands of China. • Grazing exclusion promotes multifunctionality only in less arid grasslands. • Grazing exclusion jeopardizes plant biodiversity effect on multifunctionality. • Grazing exclusion enhances the negative effect of aridity on multifunctionality. [ABSTRACT FROM AUTHOR]

• A region-specific study about boreal and temperate forest multifunctionality. • Relationships between biodiversity and multifunctionality change with environment. • Mass ratio effects influence boreal forest multifunctionality. • Niche complementarity effects influence temperate forest multifunctionality. Biodiversity is known to affect ecosystem functioning, and environmental stress may influence the relationships between biodiversity and ecosystem functions (BEF). However, it is still unknown how the relationship between biodiversity and ecosystem multifunctionality (BEMF) varies with the environment at regional scale. We aimed to explore the change of BEMF relationship across environmental gradients in boreal and temperate forest ecosystems, and to identify the main impact mechanisms on EMF. Based on a data set collected in Northeastern China, we quantified EMF by calculating the average of six individual functions, defined species richness and functional diversity as community diversity, and defined the community-weighted means of functional traits as functional composition. We used multifactorial linear regression to assess the effect of biodiversity indices across environmental gradients on BEMF, and used structural equation models to identify the relationships among impact factors and EMF. Community diversity and functional composition, as well as their interactions with environmental gradients, were jointly influencing the EMF. In the boreal forests, functional composition was the dominant driver of EMF. In the temperate forests, community diversity became the dominant factor impacting EMF. The results imply that BEMF relationship changes with environmental conditions. EMF is mainly influenced by the community functional traits of the dominant species (mass ratio effect) in the boreal forests. In the temperate forests, greater community diversity leads to greater resource utilization and thus greater EMF (niche complementarity effect). [ABSTRACT FROM AUTHOR]

Fertilization will cause changes in crop growth, soil microbial community and multiple ecosystem functions, but it is unclear whether and how the optimal productivity obtained by manure application and optimizing nitrogen is driven by microbial community and ecosystem multifunctionality. We explore this mechanism based on a field fertilization experiment using a split-plot design that began in 2014 with five N rates (N0, N75, N150, N225, N300) as main plots and two manure rates (M0, NPK group; M1, MNPK group) as subplots, respectively. In general, (1) grain yield was parabolically related to the N application rate. The N rates that obtained the highest yield were 150 kg ha−1 and 225 kg ha−1 for the MNPK and NPK groups, respectively. The average yield of the MNPK group was 10.5% higher than that of the NPK group. (2) Long-term fertilization management resulted in regular changes in soil multifunctionality (SMF) and the properties of various microbial communities. The richness, network complexity and soil multifunctionality of bacterial and fungal communities also increased initially and then decreased as the N rate. On average, the response ratio of soil multifunctionality to N75, N150, N225, N300 (control is N0) and M1 (control is M0) were 0.11, 0.41, 0.53, 0.44 and 1.19, respectively. The soil multifunctionality of MNPK was 260%, 722% and 101% higher than that of NPK at the tillering, jointing and harvest stages, respectively. (3) Soil multifunctionality not only always had a significant positive effect on aboveground biomass at all growth stages, but also had significant positive correlations with bacterial richness and network complexity. Based on the existing framework, we further demonstrated that high microbial richness supports multifunctionality by ensuring strong associative complexity among microorganisms. However, only bacterial network complexity always positively drove soil multifunctionality and indirectly influenced wheat growth at all growth stages in SEMs where multiple drivers were considered simultaneously (i.e., pH, SOC and biological factors). Random forest regression analysis showed that rare bacterial taxa had stronger predictive effects on soil multifunctionality than abundant taxa. Our results validate that M1N150 can ensure high yield in the study area while maintaining a high level of ecosystem function in the soil, which also contributes to the reduction of adverse environmental risks caused by fertilizer application. Importantly, the potential of microbial network complexity, especially bacterial network complexity, to influence crop growth by driving farmland ecosystem functions deserves to be explored under different crop types, cropping systems, and irrigation conditions, compared to previous microbial richness that has been simply quantified. [Display omitted] • The yield reduction caused by excessive N application was associated with SMF. • The positive effect of SMF on wheat growth decreased with the growth stage. • Microbial network complexity predicted SMF better than diversity. • SMF driven by bacterial network complexity explains more about wheat growth. • The bacteria that have the greatest driving effect on SMF mostly belong to rare taxa. [ABSTRACT FROM AUTHOR]

Continuous cropping has can majorly damage the soil ecosystem, leading to an increased prevalence of pathogenic microorganisms and severe yield losses for watermelons. Multiple prevention strategies have been adopted to overcome this obstacle, among which the application of bioorganic fertilizer can improve microbiome deterioration. However, the response of soil ecosystem multifunctionality and soil quality to fertilizer regimes under continuous cropping remains poorly understood. In this study, based on an 8-year field experiment, we evaluated soil health and ecosystem multifunctionality under different fertilization treatments. Long-term bio-organic fertilization preserved soil electrical conductivity and increased total Cu, Zn, Fe, Mn, Ca, and Mg, total and available nutrients, and enzyme activities compared with those in unfertilized control (CK) and chemical fertilizer treatments. Enzyme activities and yield rapidly changed, indicating their sensitivity to these management practices. Conversely, soil pH, biodiversity, medium/trace elements, and total NPK content were more resistant to change than enzyme activities, suggesting higher stability over time. The area of soil quality index under bio-organic fertilization was 1.2–2.9 times larger than that under CK treatment. Applying biological organic fertilizer and a mixture of chemical and organic fertilizers improved the multifunctionality decline caused by continuous cropping by 1.1–1.4 times, whereas the effect of the chemical fertilizer was weak. Soil health was positively correlated with ecosystem multifunctionality. These findings suggest that long-term bioorganic and organic fertilization is an effective strategy for improving soil quality and multifunctionality in continuous watermelon crops while also contributing toward a more sustainable agricultural system. [Display omitted] • Soil quality and multifunctionality are decreased under continuous cropping. • Bioorganic and organic fertilizers improve soil quality and multifunctionality. • Enzyme activity and pathogen abundance represent sensitive indicators. [ABSTRACT FROM AUTHOR]

• Understory and soil responses to stand density varied with stand age. • The shrub layer was less responsive to stand density changes than the herb layer. • Soil and understory quality peaked at medium density in young and middle-aged stands. • In mature plantations, low stand densities increased understory diversity and soil quality. Robinia pseudoacacia is the most important tree species used for afforestation on the Chinese Loess Plateau. However, most R. pseudoacacia plantations face environmental problems due to inappropriate initial densities. The sustainable development of R. pseudoacacia plantations is challenging due to significant knowledge gaps regarding the appropriate stand densities for maximizing ecological benefits. Herein, R. pseudoacacia plantations of three age classes—young, middle-aged, and mature—were sampled in the loess hilly-gully region of northern Shaanxi Province, China. Based on stand density, R. pseudoacacia plantations in each age class were categorized as low (<1000 trees ha−1), medium (1000–1500 trees ha−1), and high (>1500 trees ha−1) density. We analyzed the effects of stand density on soil physicochemical properties, understory vegetation community structure, and ecosystem multifunctionality. In young stands, a medium stand density significantly increased the Shannon-Wiener index, species richness, and above-ground biomass of herbaceous communities. In middle-aged stands, stand density had no significant effects on understory diversity, whereas medium-density stands showed increased understory above-ground biomass. In mature stands, low-density stands significantly increased understory above-ground biomass and species richness of herbaceous communities. In all age classes, stand density did not significantly affect shrubby community composition, but herbaceous communities shifted compositionally towards shade-tolerant and drought-tolerant species as stand density increased. In the soils of young and middle-aged stands, organic carbon, ammonium nitrogen, nitrate nitrogen, available phosphorus, and water content were highest in medium-density stands, whereas in mature stands, these variables were highest in low-density plantations. In young, middle-aged, and mature stands, the ecosystem multifunctionality indices were highest at densities of 1000–1500, 1000–1500, and < 1000 trees ha−1, respectively. We concluded that the effects of stand density on ecosystem functions in R. pseudoacacia plantations varied with stand age. Our findings highlight a need to implement age-based stand density management strategies for R. pseudoacacia plantations to improve their ecological benefits. [ABSTRACT FROM AUTHOR]

Long-term fertilization significantly affected the function, diversity, and structure of soil microbial communities, which performed an indispensable role in maintaining ecosystem multifunctionality. However, the mechanism of how balanced fertilization affects soil microbial composition, function, and ecosystem multifunctionality is still poorly understood, especially during the whole plant life cycle, which will hinder our understanding the consequences of reducing phosphorus (P) fertilizer inputs as required in sustainable agriculture. Herein, the soil samples from a P fertilization field (with 0, 70, and 120 kg P 2 O 5 ha−1 yr−1) at different stages of wheat (greenup stage (GP: Zadoks stage 26), elongation stage (EP: Zadoks stage 31), and flowering stages (FP: Zadoks stage 64)) were collected to investigate the effects of P fertilizer input on soil bacterial community, assembly, bacterial functionality, and multifunctionality in the Loess plateau. The results showed that soil bacterial diversity and functional groups (microbial P limitation) increased as wheat developed, but the bacterial network complexity and multifunctionality decreased. The highest soil bacterial network complexity, ecosystem multifunctionality, and homogeneous selection (deterministic processes) were observed in the balanced P fertilization treatment (P70), but wheat P uptake, biomass, and grain yield were similar at P rates of 70 and 120 kg P 2 O 5 ha−1. The microbial nutrient limitation was also altered by both P fertilization and wheat growth stages. Moreover, the changes in soil available P and bacterial network complexity were the major determining factors of different microbial C and P limitations and ecosystem multifunctionality. Our results also showed that the core microorganisms with special functions drive the ecosystem multifunctionality by altering the community structure and network complexity of the microbes. Therefore, our result highlights the importance of soil available P and bacterial network complexity in maintaining ecosystem multifunctionality under P fertilizer inputs and provides support for the use of balanced P fertilization in sustainable dryland wheat production from the aspect of ecosystem multifunctionality. • Wheat P uptake, biomass, and grain yield were not reduced under balanced P input. • Soil bacterial network complexity and multifunctionality decreased as wheat developed. • Balanced P input significantly decreased microbial C limitation. • Highest network complexity and multifunctionality were observed under balanced P input. • Soil available P and network complexity were the major factors affecting multifunctionality and plant production. [ABSTRACT FROM AUTHOR]

• The negative effect of grazing on the reduction of EMF in Chinese grasslands cannot be ignored. • Fungal diversity was closely related to the response of EMF to heavy grazing and typical grasslands. • Soil fungal and bacterial diversity mitigated the decrease in EMF between 0–5 years of grazing. Grazing can alter soil microbial diversity and ecosystem multifunctionality (EMF) through feeding, trampling, and excreta deposition. However, it remains unclear how grazing intensity and grazing duration across Chinese grasslands affect the relationship between soil microbial diversity and EMF. Here, we conducted a meta-analysis to analyze the responses of soil microbial diversity and EMF to grazing disturbance using 54 publications with 62 sample sites from alpine grasslands and temperate grasslands in China. The results showed that EMF tended to decrease with increasing grazing duration and grazing intensity. Bacterial diversity was significantly and negatively correlated with EMF under moderate grazing, whereas fungal diversity was significantly and positively correlated with EMF under heavy grazing. Both fungal and bacterial diversity regulated the effects of grazing on EMF with grazing durations of up to 5 years. Furthermore, bacterial diversity was negatively correlated with EMF in typical steppe but positively in alpine grassland, and fungal diversity was positively correlated with EMF in typical steppe. Our results highlight the importance of microbial diversity in maintaining the multifunctionality of grassland ecosystem. We suggest that both grazing intensity, duration and grassland type should be seriously considered in the conservation of biodiversity and the sustainability of grassland ecosystem services and functions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A high amount of added soil increases multifunctionality of degraded grasslands. • Biotic and abiotic factors are important to influence ecosystem functions. • Fungal richness and network complexity positively influence ecosystem functions. Soil addition is now widely used in the restoration of degraded ecosystems, but how soil addition influences multiple ecological functions of degraded grasslands, and whether these effects depend on the amount and type of soil inoculum, are still not clear. We performed two parallel experiments to examine how two different donor soil types and two amounts of donor soil addition affect the restoration of degraded grassland. In a field experiment at a degraded grassland site where the top layer of the soil was removed (5 cm), we assessed the effect of addition of soil collected from two different ecosystems (upland meadow and meadow steppe) and addition of different amounts of soil (0 cm, 1 cm and 3 cm) on ecosystem multifunctionality. In a microcosm experiment, we examined the effects of soil biotic and abiotic factors on ecosystem functions by inoculating sterilized and non-sterilized soil. Soil addition promoted the restoration of degraded grassland, particularly when higher amounts of soil were added. Both biotic and abiotic factors increased ecosystem multifunctionality. Biotic factors, especially fungal richness and network complexity, had the strongest positive effects on ecosystem multifunctionality. Our study reveals the importance of fungal communities in soil for improving ecosystem multifunctionality in restoration of degraded grassland. Future studies should explore the effects of joint addition of arbuscular mycorrhizal fungi and saprophytic fungi on the ecosystem functions of degraded grasslands. [ABSTRACT FROM AUTHOR]

As an effective field management practice for better crop productivity, fertilization showed profound impacts on soil health by altering soil chemical, physical, and biological processes. But, how soil health and related ecosystem multifunctionality (EMF) respond to long-term fertilization remains unclear. In this study, based on a 29-year field experiment, we evaluated soil health and EMF under chemical fertilization versus manure application. Long-term manure application maintained soil pH, significantly increased water-stable aggregate, total and available nutrients, microbial biomass and community (bacteria, fungi, and actinomycetes, etc.), and enzyme activities compared with treatments under chemical fertilizers. Edaphic factors of soil organic carbon (SOC), available phosphorous (AP), fungi, cation exchange capacity, and clay content were identified as key indicators of soil health evaluation by network analysis. The soil health indices (SHIs) of chemical fertilizer treatments were 39–52% lower than that of natural vegetation recovery, with carbon and nutrient cycling, soil biodiversity maintenance, and productivity at low ecosystem function levels. Manure application enhanced soil health by 150–196% compared to unfertilized control by improving SOC, P availability, and sustaining ecosystem functions with carbon and nutrient cycling, soil biodiversity maintenance, buffering and filtering capacity, and productivity at relatively high ecosystem function levels. The individual functions of carbon and nutrient cycling, physical structure stability, and productivity illustrated sensitive responses to the increase in soil health, while inherent soil functions of buffering and filtering capacity and soil biodiversity maintenance were only correlated with high soil health. Manuring improved soil functions and soil health simultaneously, indicating a synergistic relationship. Our findings highlight the significance of manure application to improve soil health and sustain functions in intensive agricultural systems. • SOC, AP, fungi, clay content, and CEC were identified as key indicators. • Natural vegetation recovery improved SHI compared with chemical fertilization. • Manuring improved soil health by sustaining soil multifunction at high levels. • Soil functions had diverse responses to soil health shifts. [ABSTRACT FROM AUTHOR]

Relating biodiversity to ecosystem functioning in natural communities has become a paramount challenge as links between trophic complexity and multiple ecosystem functions become increasingly apparent. Yet, there is still no generalised approach to address such complexity in biodiversity–ecosystem functioning (BEF) studies. Energy flux dynamics in ecological networks provide the theoretical underpinning of multitrophic BEF relationships. Accordingly, we propose the quantification of energy fluxes in food webs as a powerful, universal tool for understanding ecosystem functioning in multitrophic systems spanning different ecological scales. Although the concept of energy flux in food webs is not novel, its application to BEF research remains virtually untapped, providing a framework to foster new discoveries into the determinants of ecosystem functioning in complex systems. [ABSTRACT FROM AUTHOR]

Soil multifunctionality is the consequence of biotic interactions that drive decomposition, nutrient cycling and net primary production. Energy flux describes the energy consumed and transferred among multitrophic groups in the soil food web, which are logically linked to multifunctionality. In a subtropical agroecosystem with an annual sweet potato-oilseed rape rotation, we explored how biochar and synthetic fertilizer jointly affected agroecosystem multifunctionality (e.g., crop production, soil carbon storage and nutrient cycling) and the energetic structure of the nematode food web during two consecutive years. Results showed that biochar increased soil multifunctionality by 37–110% mainly by promoting a uniform energy flow through the soil nematode food web, which was largely due to increased energy fluxes of fungivores and omnivores-carnivores at the expense of decreased energy flux through herbivores. Applying a lower rate of synthetic fertilizer led to non-uniform energy flow in the soil nematode food web, suggesting that nitrogen limitation could offset the stimulatory effect of biochar on soil multifunctionality. This was because biochar induced oligotrophic conditions (a stoichiometry-induced nitrogen limitation), effectively warranting that continuous biochar application would aggravate nutrient limitations to crops, especially when low rates of synthetic fertilizer are applied. Notably, soil nutrient impoverishment could lead to resource reallocation from aboveground shoot to belowground root production, thereby fueling the energy flow through the herbivore channel. Our findings highlight the importance of balancing biochar and synthetic fertilizer applications to sustain a stable energetic structure in soil nematode food webs, which are associated with greater crop production and soil health in subtropical region. • Biochar increased the energy flow uniformity and arable soil multifunctionality. • Energy flow uniformity was positivity related to multifunctionality. • Biochar stimulatory effects were weakened when reducing synthetic fertilizer input. • Sustaining multifunctionality needs complementary input of both biochar and nutrients. [ABSTRACT FROM AUTHOR]

• Diversity of different biota groups showed distinct responses to natural restoration. • Multitrophic network complexity continuously increased with progressing succession. • Soil network complexity better indicates ecosystem functioning than biodiversity. • Key biotic and abiotic elements for forming a networked community were identified. Natural restoration of abandoned land is a widely used strategy to restore ecosystem functions. Previous studies mainly focused on restoring the diversity of a limited number of organism groups, ignoring that biodiversity loss occurs across multiple trophic levels and that ecological processes depend on complex interactions. In this study, the effects of natural restoration on diversity and network of multiple soil trophic groups and 10 variables related to a broad range of ecosystem functions were investigated along a 50-year natural restoration chronosequence. The diversity of different trophic groups had distinct responses to natural restoration. Furthermore, the complexity of soil networks, indicated by co-occurrence patterns across trophic levels, significantly increased with progressing succession. Ecosystem multifunctionality was significantly positively associated with soil network complexity than diversity in all individual and multiple trophic groups (multitrophic diversity). After controlling for confounding factors of ecosystem multifunctionality, these relationships remained robust, including geographic location and soil attributes. Moreover, the positive association between multifunctionality and soil biodiversity across restoration sites could be indirectly due to the soil network complexity. Diversity levels of soil archaea and invertebrates, and soil nutrient cations were significantly associated with the interconnectivity of complex multitrophic networks. Therefore, this study provides insights into the important role of soil network structure in maintaining ecosystem functioning, highlighting the necessity of considering potential interactions among soil organisms in the restoration of degraded ecosystems rather than simply focusing on the number of species. [ABSTRACT FROM AUTHOR]

[Display omitted] • Agricultural residues increase ecosystem multifunctionality. • Agricultural residues increase soil microbe-nematode network complexity. • Soil microbial biomass is positively correlated with ecosystem multifunctionality. • Integrated crop-livestock system obtained the highest economic benefit. The negative environmental impacts of chemical fertilizers have been recognized for a long time, and the returning of agricultural residues to the soil is considered a sustainable agricultural practice. However, few studies have focused on the ecological and economic benefits of returning agricultural residues to the soil simultaneously. Using a 16-year field experiment, we integrally evaluated and compared the ecological and economic benefits of six fertilization practices. The treatments included a no-fertilizer control, conventional chemical NPK fertilization, and partial substitutions of the NPK in chemical fertilizers with a low (30%) or high (60%) level of agricultural residues (straw or cattle manure). The amount of N, P and K inputs remained constant across all fertilization treatments, but the source of N, P and K differed. Ecological benefits were assessed through a study of ecosystem multifunctionality and through a co-occurrence network analysis of the soil micro-food web. Our results showed that applications of agricultural residues increased soil microbial biomass and diversity, soil co-occurrence network complexity, and ecosystem multifunctionality compared with the chemical fertilization alone. The high-level straw substitution treatment supported the greatest ecosystem multifunctionality and soil network complexity. Random Forest regression analysis revealed that soil microbial biomass and fungal diversity were important biological traits associated with ecosystem multifunctionality. The economic benefit was highest when cattle manure was returned to the soil, lowest when crop straw was returned to the soil, and intermediate with chemical fertilization alone. Therefore, the return of cattle manure to the soil provided comprehensive ecosystem services. Our findings increase the understanding of the relationships between economic and ecological effects of returning agricultural residues to the soil. [ABSTRACT FROM AUTHOR]

Fencing has been extensively used for the restoration of grassland degraded by human disturbance. However, its effects on ecosystem functions and services are still controversial. Here, we evaluated the response of ecosystem multifunctionality (EMF) to 7 years of grazing exclusion based on ten individual functions, and compared grazing exclusion with two common practices (mowing and grazing) in a typical steppe in Inner Mongolia. Plant and microbial diversity and three edaphic factors (soil pH, moisture and temperature) were also investigated to explore the main drivers regulating EMF. Compared with continuous grazing, fencing improved EMF mainly by increasing soil nutrient contents, including soil organic carbon, ammonium nitrogen, nitrate nitrogen and available phosphorus. No significant differences were found between fencing and mowing for all ten individual functions and EMF. Plant and fungal diversity were comparable between fencing and grazing, but were lower than under mowing, and bacterial diversity was similar between all three management practices. Soil pH, moisture and temperature were also affected by fencing. Structural equation modeling showed that EMF was mainly driven by soil moisture in the fencing and mowing plots, but by plant and bacterial diversity in the grazing plots. Our results suggest that relative to grazing, fencing and mowing are both feasible strategies to enhance EMF, and that mowing may be more conducive to biodiversity conservation. This study demonstrates that, maintenance of soil moisture is critical for the restoration of EMF in Inner Mongolia's typical steppe. [Display omitted] • Contrast with grazing, fencing improved EMF mainly through enhancing soil nutrient contents. • Fencing and mowing had comparable EMF, but mowing was preferable for biodiversity conservation. • EMF was regulated by edaphic factors in fencing and Mowing, but by biotic factors in grazing. • Maintenance of soil moisture is critical for the restoration of EMF. [ABSTRACT FROM AUTHOR]

Soil microorganisms are major regulators of ecosystem functioning and are under threat from human-induced disturbances. Among these threats is grassland degradation, which is estimated to affect 49% of the grassland area worldwide, threatening biodiversity and ecosystem functioning. Yet, we currently lack an understanding of how grassland degradation influences belowground microbial communities, their stability, and functioning, and how effective restoration efforts are for the recovery of these important belowground properties. Here, we assessed soil fungal network complexity and a suite of ecosystem functions along a well-characterised gradient of grassland degradation and restoration on the Qinghai-Tibetan Plateau, and conducted an accompanying microcosm experiment designed to test the effects of complexity on stability in soil fungal communities. We found that with increasing levels of grassland degradation, soil fungal communities became less complex and were less compositionally stable when confronted with drought under laboratory conditions. Moreover, this degradation-induced reduction in fungal community complexity was associated with lower ecosystem multifunctionality. However, fungal communities and ecosystem multifunctionality failed to recover even after ten years of grassland restoration. Our results indicate that degradation-induced simplification of fungal communities can potentially impair fungal community stability and ecosystem multifunctionality, thereby highlighting the need to protect and restore healthy grasslands with complex belowground microbial communities. • Grassland degradation resulted in less complex soil fungal communities, which were less stable when confronted with drought. • Degradation-induced reduction in fungal community complexity was associated with lower ecosystem multifunctionality. • Fungal communities and ecosystem multifunctionality failed to recover even after ten years of grassland restoration. [ABSTRACT FROM AUTHOR]

Bioplastics (biodegradable plastics) potentially offer an encouraging alternative to conventional (petroleum-based) plastics. In practice, bioplastics inevitably generate a large number of bio-microplastics (bio-MPs, diameter <5 mm) during the degradation progress. However, the impact of bio-MPs on plant and soil health within agroecosystems remains incomplete. Here, a field study was conducted to investigate the effect of two shapes (fiber and powder) of pure polylactic acid (PLA) bio-MPs on oat (Avena sativa L.) and soybean (Glycine max (L.) Merr.) growth and soil health. Our results showed that PLA application at a representative soil loading rate of 0.2% (w/w) had no significant effect on soil enzyme activities, soil physicochemical properties (soil water content, pH, etc.), root characteristics, plant biomass, and crop yield. Thus, we conclude that soil quality, plant health, and ecosystem multifunctionality were not affected by PLA over one growing season (5 months) in the presence of either bio-MP shape (fiber and powder) for either crop species (oat and soybean). Overall, PLA based bio-MPs may not pose a significant threat to agroecosystem functions in the short term (days to months) in the field, thus may provide a viable environmentally benign solution to replace traditional non-biodegradable plastics in agroecosystems. [Display omitted] • Bio-microplastics (bio-MPs) did not affect the soil enzyme activities in a field trial. • Oat and soybean growth was unaffected by the shape of added bio-MPs. • Soil quality index showed little change with bio-MPs addition compared to control. • No bio-MPs shape-dependent impact on soil ecosystem multifunctionality was observed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Warming showed stronger negative effects on plant health than microplastics. • MPs did not exaggerate the effects of warming on ecosystem multifunctionality. • Bioplastic (PHA) enhanced microbial biomass, enzyme production and soil quality. • PHA addition induced strong plant–microbe competition for nutrients in soil. • PHA inhibited plant growth and lowered the plant health index. Many anthropogenic pressures are being exerted on terrestrial ecosystems globally, perhaps the most pressing of which include microplastics (MPs; <5 mm in size) pollution and climate change, both of which may have unpredictable consequences on soil ecosystem functioning. We therefore hypothesized that a dual pressure (MPs and warming) on plant-soil functioning would be more severe than either stress alone. Thus, we studied the interactive effects of MPs and warming on soil quality and ecosystem multifunctionality. Maize (Zea mays L.) was grown for 6 weeks under ambient and warming (+5 °C) conditions in the absence (control) or presence (5 % loading) of either polyethylene (PE), polyvinylchloride (PVC), or biodegradable polyhydroxyalkanoate (PHA). We found that PHA stimulated microbial biomass and enzyme activity due to the additional C resources, thus changing soil quality and ecosystem multifunctionality under ambient temperature. However, the accelerated microbial growth in PHA-treated soils also promoted N immobilization and plant–microbe nutrient competition, consequently decreasing plant health index by 65 % relative to the Control. As PVC and PE are chemically more stable than PHA, they had limited effect on soil quality and plant health under ambient temperature in the short term (6 weeks). Most of the negative impacts of MPs only occurred under ambient temperature, with few effects evident under warming conditions. This suggested that the effect of heat stress (evidenced by stunted growth and chlorophyll content) was noticeably more acute than the effect of MPs. In conclusion, we showed that MPs do affect plant health, soil quality, and ecosystem multifunctionality but these effects on plant-soil health were not exacerbated by the effects of a warmer climate. [ABSTRACT FROM AUTHOR]

The contributions of soil microbial diversity for the multifunctionality of ecosystem functions remain little understood despite the well-known importance of soil microbial communities for regulating many ecosystem functions. Existing studies have typically focused on the role of univariate diversity or composition metrics, while ignoring that ecosystem processes are carried out via complex webs of co-occurrence networks among microbiome members. Here, the relationships of soil microbial diversity and network complexity (reflected by linkage density of inferred co-occurrence patterns) with multiple types of ecosystem functions (ecosystem multifunctionality) were assessed along a multi-elevation gradient (3755–5120 m) on the Tibetan Plateau. These functions included a suite of 18 variables related to soil nutrient status, soil carbon, nitrogen, and phosphorous cycles, plant growth, mitigation of greenhouse gases, and control of potential fungal plant pathogens in soils. The findings showed that the diversity, network complexity of both bacterial and fungal communities, as well as ecosystem multifunctionality significantly declined with increasing elevation. Although significant linear positive relationships were identified between diversity, network complexity of both microbial communities, and ecosystem multifunctionality, the relationships of network complexity had more positive relationships and explained more variance than diversity. These relationships remained robust when the confounding multifunctionality drivers (i.e., climatic, soil, and biotic factors) were simultaneously accounted for and when multiple multifunctionality approaches (i.e., multiple single functions, average multifunctionality, multithreshold, and multidimensional functions) were used. Further analysis showed that microbial diversity effects on multifunctionality were indirectly driven by microbial network complexity. This explicit empirical evidence shows that microbial network complexity enables a better prediction of ecosystem functions than the simplified microbial diversity metrics most studies applied in the past. Our results highlight the importance of co-occurrence networks as a key component of microbial biodiversity linking it with ecosystem multifunctionality. • Ecosystem multifunctionality declined with elevation on the Tibetan Plateau. • Microbial network complexity predicted multifunctionality better than diversity. • Diversity effects on multifunctionality were indirectly driven by network complexity. [ABSTRACT FROM AUTHOR]

• We assessed the relationship between biodiversity and ecosystem multifunctionality of alpine meadows. • We used a neural network model to predict the importance of biodiversity to ecosystem multifunctionality. • Biodiversity collectively explains ecosystem multifunctional processes. • Species richness is an essential driver of ecosystem multifunctionality. Exploring the spatial pattern of biodiversity in different dimensions and its relationship with ecosystem multifunctionality was one of the hot topics in ecological research, and elevation was an important topographic factor affecting biodiversity changes. The maintenance mechanism of ecosystem multifunctionality (EMF) relationship between different dimensions of biodiversity and ecosystem multifunctionality in alpine meadows on the eastern Qinghai-Tibetan Plateau was still unclear. This paper investigates the elevation patterns of species, functions, and phylogenetic diversity of plant communities in alpine meadows on the eastern Qinghai-Tibetan Plateau and their effects on EMF using factor analysis and the radial basis function (RBF) neural network model. The results showed that (1) the species and phylogenetic diversity indices (except MPD index) increased and then decreased with elevation; the functional diversity indices FRic and FEve showed a decreasing trend with elevation, while FDiv showed the opposite. (2) Ecosystem multifunctional indices for the five elevation gradients were 3000 m > 3250 m > 3500 m > 3750 m > 4000 m. There were significant correlations between biodiversity and ecosystem functions. Species richness, Simpson, FRic, and FDiv increased with increasing EMF, but the relationship between phylogenetic diversity and EMF was insignificant. (3) Among the biodiversity indices, species richness and functional richness indices had a greater impact on EMF and were also important drivers to explain changes in EMF, followed by PD indices. The high biodiversity of alpine meadows can contribute to the supply of multifunctional ecosystems, making them healthier and more stable. [ABSTRACT FROM AUTHOR]

It is well established that grassland degradation negatively affects ecosystem functioning. Many studies have explored the changes of individual functions involved with grassland degradation, while fewer considered an ecosystem multifunctionality (EMF) summarizing the multiple simultaneous changes in the response of ecosystem functions to grassland degradation. Further, how changes in multiple ecosystem functions with grassland degradation in relation to above- and belowground biodiversity has been rarely explored. Here we assessed the effects of grassland degradation on nutrient cycling, biological productivity and overall EMF in a Tibetan Plateau alpine grassland. We quantified both the direct effect of grassland degradation and indirect effects mediated by changes in plant richness, soil biodiversity and abiotic factors, on EMF. We found that 1) there were negative effects of grassland degradation on EMF, plant richness and soil biodiversity; 2) EMF was positively related to plant richness, soil biodiversity and soil moisture, but not with soil pH; 3) grassland degradation had a strong negative direct effect on EMF and the positive interaction between aboveground and belowground biodiversity enhanced the negative effects on EMF, especially, through plant richness. Our study reveals how grassland degradation affects EMF directly and indirectly through biotic and abiotic pathways and highlights the importance of both above- and belowground biodiversity for maintaining multiple ecosystem functions. Protecting belowground diversity is as important as preserving aboveground diversity for maintaining ecosystem functioning and the restoration of degraded grassland ecosystem. • Grassland degradation negatively affects EMF, plant richness and soil biodiversity. • EMF is closely associated with biodiversity and soil moisture but not with soil pH. • The interaction between biodiversity enhances the effects of degradation on EMF. [ABSTRACT FROM AUTHOR]

Grazing exclusion is widely used to restore the grasslands that degraded by overgrazing. However, it is not clear how the interaction of above- and below-ground functioning affects the restoration of ecosystem multifunctionality in long-term grazing exclusion. Here, long-term grazing exclusion experiments were performed in a desertified alpine grassland of eastern Tibetan Plateau. We measured critical ecosystem functioning indices including species diversity, community biomass, soil water content and soil nutrient concentrations. Our results showed that both above- and below-ground functioning increased over restoration time, with the mean values increased by 187%, 112%, 195%, 92% and 242% from GE2 to GE12 for above-ground biomass, soil water content, soil organic matter, soil total nitrogen and soil total phosphorus, respectively. Species diversity tended to an "inverted U curve" over restoration time. The response of belowground functioning lagged behind that of aboveground functioning during the restoration process. The trade-off values between above- and below-ground ecosystem functioning in the early restoration stage was significantly higher (P < 0.01) than that in the late restoration stage. We also found that the feedback of aboveground functioning on belowground functioning shifted from negative in the early restoration stage to positive in the late stage. The findings of this study suggested that the interaction between above- and below-ground functioning controls the restoration of ecosystem multifunctionality. This study is valuable for improving sustainable grassland policies and optimizing desertified grassland management on the Tibetan Plateau. [Display omitted] • The restoration of belowground functioning lagged behind that of aboveground functioning in the restoration sequences. • The interaction between above- and below-ground functioning gradually turned from a trade-off relationship to synergistic. • Response of aboveground functioning on belowground functioning shifted from negative to positive from early to late stage. • The interaction between above- and below-ground functioning controls the restoration of ecosystem multifunctionality. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three microbial taxonomic groups show consistent water-depth distance-decay patterns. • Ecosystem functions and multifunctionality generally increase towards deep water. • Community composition and evenness dominate ecosystem multifunctionality variations. • Water depth indirectly affects microbial diversity-ecosystem multifunctionality links. Lake level or water depth are key physical variables known to respond dramatically to climate change, especially in arid regions, and their fluctuations exert substantial influences on lake biodiversity and ecosystem functioning. However, it is unclear how multiple ecosystem functions (i.e., ecosystem multifunctionality, EMF) respond to changes in water depth and how aquatic community attributes, such as species richness, evenness and community compositions, are linked to EMF along water depth gradients. Lake Hulun, a representative of semiarid-region lake in China, has experienced serious lake area shrinkage over the past 20 years. Here, we explored the water-depth patterns of three microbial taxonomic groups of bacteria, archaea and fungi and nine ecosystem functions related to nutrient cycling in Lake Hulun. We further examined the relative importance of different community attributes on EMF variations. We found that the community compositions of bacteria, archaea and fungi showed consistent water-depth decay patterns, and EMF and most individual ecosystem functions involved in C, N, P and S cycling increased with water depth. Further, EMF was predominantly mediated by microbial evenness and community composition, but not species richness, as predicted by the traditional theory of biodiversity-ecosystem functioning relationships. In addition, water depth indirectly affected the relationships between the microbial community and EMF via sediment nutrient contents. These findings indicate that the water depth changes under climate change could substantially alter ecosystem structure and functioning in arid regions. We further emphasize the necessity of including multiple community attributes in biodiversity-EMF relationship research to clarify the biotic and abiotic forces underlying EMF variations. [ABSTRACT FROM AUTHOR]

• We described floodplain functioning with the ecosystem multifunctionality index. • Both negative and positive correlation occurred between floodplain functions. • Multifunctionality declines with distance to the water table and hydrological distance. • Effect of distance to the water table is stronger than of hydrological distance. • Multifunctionality indices link floodplain functioning with flooding. Various ecosystem functions provided by floodplains depend on a natural river activity and floodplain morphology. Therefore, anthropogenic alterations of rivers modify their flooding regimes and may affect the provisioning of numerous ecosystem functions. Restoration projects, which aim at reestablishing natural processes of floodplains, require a better understanding of the ecosystem's ability to simultaneously provide multiple functions (multifunctionality) and how this relates to the environmental template. Here we investigate the relationship between environmental drivers and ecosystem multifunctionality. We focus on 24 ecosystem functions, representing five ecosystem services provided by floodplains of the Mulde River: plant productivity, biodiversity provisioning, retention of sediments, nutrients and pollutants. These functions were measured on 74 plots located on three well preserved floodplain sites of the Mulde River. We described synergies and trade-offs between single functions using correlations and calculated quantitative measures of ecosystem multifunctionality, quantified as the number of functions provided above either 50% of maximal functioning, or 75% of maximal functioning. We then explored relations of multifunctionality with two environmental factors, which also affect the probability of flooding i.e., the hydrological distance and the distance to the water table. Although numerous functions related to sedimentation processes were positively correlated to each other, they traded off with functions related to biodiversity provisioning. This advocates the application of a holistic measure of ecosystem functioning. Multifunctionality indices decreased with an increase of both distance to the water table and hydrological distance, with effects of the distance to the water table being most strongly negative. These findings imply that ecosystem multifunctionality is highest at sites which are flooded regularly. We conclude that restoration attempts which shorten hydrological distance and distance to the water table, like removal of artificial embankments or reconstruction of side channels, may have a positive effect not only on single functions, but also on overall ecosystem multifunctionality. We also advocate the application of a multifunctionality measure to facilitate management and restoration of floodplains. [ABSTRACT FROM AUTHOR]