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The European Journal of Soil Science (EJSS) is celebrating its 75th anniversary in March 2024. Published by Wiley on behalf of the British Society of Soil Science (BSSS), the journal has evolved over the years and supports international authors and a diverse readership. It has published over 2,000 papers since 1949, many of which are still highly cited today. The EJSS accepts various types of articles and has seen increased online engagement. They prioritize fairness in publishing, open data sharing, and author diversity. The journal looks forward to continued support from its stakeholders. [Extracted from the article]

Nitrogen (N) deposition is a component of global change that has considerable impact on belowground carbon (C) dynamics. Plant growth stimulation and alterations of fungal community composition and functions are the main mechanisms driving soil C gains following N deposition in N‐limited temperate forests. In N‐rich tropical forests, however, N deposition generally has minor effects on plant growth; consequently, C storage in soil may strongly depend on the microbial processes that drive litter and soil organic matter decomposition. Here, we investigated how microbial functions in old‐growth tropical forest soil responded to 13 years of N addition at four rates: 0 (Control), 50 (Low‐N), 100 (Medium‐N), and 150 (High‐N) kg N ha−1 year−1. Soil organic carbon (SOC) content increased under High‐N, corresponding to a 33% decrease in CO2 efflux, and reductions in relative abundances of bacteria as well as genes responsible for cellulose and chitin degradation. A 113% increase in N2O emission was positively correlated with soil acidification and an increase in the relative abundances of denitrification genes (narG and norB). Soil acidification induced by N addition decreased available P concentrations, and was associated with reductions in the relative abundance of phytase. The decreased relative abundance of bacteria and key functional gene groups for C degradation were related to slower SOC decomposition, indicating the key mechanisms driving SOC accumulation in the tropical forest soil subjected to High‐N addition. However, changes in microbial functional groups associated with N and P cycling led to coincidentally large increases in N2O emissions, and exacerbated soil P deficiency. These two factors partially offset the perceived beneficial effects of N addition on SOC storage in tropical forest soils. These findings suggest a potential to incorporate microbial community and functions into Earth system models considering their effects on greenhouse gas emission, biogeochemical processes, and biodiversity of tropical ecosystems. [ABSTRACT FROM AUTHOR]

Approximately a third of all annual greenhouse gas emissions globally are directly or indirectly associated with the food system, and over a half of these are linked to livestock production. In temperate oceanic regions, such as the UK, most meat and dairy is produced in extensive systems based on pasture. There is much interest in the extent to which such grassland may be able to sequester and store more carbon to partially or completely mitigate other greenhouse gas emissions in the system. However, answering this question is difficult due to context-specificity and a complex and sometimes inconsistent evidence base. This paper describes a project that set out to summarize the natural science evidence base relevant to grassland management, grazing livestock and soil carbon storage potential in as policy-neutral terms as possible. It is based on expert appraisal of a systematically assembled evidence base, followed by a wide stakeholders engagement. A series of evidence statements (in the appendix of this paper) are listed and categorized according to the nature of the underlying information, and an annotated bibliography is provided in the electronic supplementary material. [ABSTRACT FROM AUTHOR]

Bioenergy crops have a secondary benefit if they increase soil organic C (SOC) stocks through capture and allocation below-ground. The effects of four genotypes of short-rotation coppice willow (Salix spp., ‘Terra Nova’ and ‘Tora’) and Miscanthus (M. × giganteus (‘Giganteus’) and M. sinensis (‘Sinensis’)) on roots, SOC and total nitrogen (TN) were quantified to test whether below-ground biomass controls SOC and TN dynamics. Soil cores were collected under (‘plant’) and between plants (‘gap’) in a field experiment on a temperate agricultural silty clay loam after 4 and 6 years’ management. Root density was greater under Miscanthus for plant (up to 15.5 kg m−3) compared with gap (up to 2.7 kg m−3), whereas willow had lower densities (up to 3.7 kg m−3). Over 2 years, SOC increased below 0.2 m depth from 7.1 to 8.5 kg m−3 and was greatest under Sinensis at 0-0.1 m depth (24.8 kg m−3). Miscanthus-derived SOC, based on stable isotope analysis, was greater under plant (11.6 kg m−3) than gap (3.1 kg m−3) for Sinensis. Estimated SOC stock change rates over the 2-year period to 1-m depth were 6.4 for Terra Nova, 7.4 for Tora, 3.1 for Giganteus and 8.8 Mg ha−1 year−1 for Sinensis. Rates of change of TN were much less. That SOC matched root mass down the profile, particularly under Miscanthus, indicated that perennial root systems are an important contributor. Willow and Miscanthus offer both biomass production and C sequestration when planted in arable soil. [ABSTRACT FROM AUTHOR]

But this is far from the full value that could be extracted from a dataset, if the ingenuity of other researchers, perhaps combined with other datasets, could be applied to the dataset. Data articles should give sufficient information to enable other scientists, whether soil scientists or those in related disciplines, to properly use the datasets in their own research. These datasets are sometimes re-used or integrated with other datasets by the original researchers or selected collaborators. [Extracted from the article]

Microbial necromass is a large and persistent component of soil organic carbon (SOC), especially under croplands. The effects of cropland management on microbial necromass accumulation and its contribution to SOC have been measured in individual studies but have not yet been summarized on the global scale. We conducted a meta‐analysis of 481‐paired measurements from cropland soils to examine the management effects on microbial necromass and identify the optimal conditions for its accumulation. Nitrogen fertilization increased total microbial necromass C by 12%, cover crops by 14%, no or reduced tillage (NT/RT) by 20%, manure by 21%, and straw amendment by 21%. Microbial necromass accumulation was independent of biochar addition. NT/RT and straw amendment increased fungal necromass and its contribution to SOC more than bacterial necromass. Manure increased bacterial necromass higher than fungal, leading to decreased ratio of fungal‐to‐bacterial necromass. Greater microbial necromass increases after straw amendments were common under semi‐arid and in cool climates in soils with pH <8, and were proportional to the amount of straw input. In contrast, NT/RT increased microbial necromass mainly under warm and humid climates. Manure application increased microbial necromass irrespective of soil properties and climate. Management effects were especially strong when applied during medium (3–10 years) to long (10+ years) periods to soils with larger initial SOC contents, but were absent in sandy soils. Close positive links between microbial biomass, necromass and SOC indicate the important role of stabilized microbial products for C accrual. Microbial necromass contribution to SOC increment (accumulation efficiency) under NT/RT, cover crops, manure and straw amendment ranged from 45% to 52%, which was 9%–16% larger than under N fertilization. In summary, long‐term cropland management increases SOC by enhancing microbial necromass accumulation, and optimizing microbial necromass accumulation and its contribution to SOC sequestration requires site‐specific management. [ABSTRACT FROM AUTHOR]

It is vital to understand responses of soil microorganisms to predicted climate changes, as these directly control soil carbon (C) dynamics. The rate of turnover of soil organic carbon is mediated by soil microorganisms whose activity may be affected by climate change. After one year of multifactorial climate change treatments, at an undisturbed temperate heathland, soil microbial community dynamics were investigated by injection of a very small concentration (5.12 µg C g−1 soil) of 13C-labeled glycine (13C2, 99 atom %) to soils in situ. Plots were treated with elevated temperature (+1°C, T), summer drought (D) and elevated atmospheric carbon dioxide (510 ppm [CO2]), as well as combined treatments (TD, TCO2, DCO2 and TDCO2). The 13C enrichment of respired CO2 and of phospholipid fatty acids (PLFAs) was determined after 24 h. 13C-glycine incorporation into the biomarker PLFAs for specific microbial groups (Gram positive bacteria, Gram negative bacteria, actinobacteria and fungi) was quantified using gas chromatography-combustion-stable isotope ratio mass spectrometry (GC-C-IRMS). Gram positive bacteria opportunistically utilized the freshly added glycine substrate, i.e. incorporated 13C in all treatments, whereas fungi had minor or no glycine derived 13C-enrichment, hence slowly reacting to a new substrate. The effects of elevated CO2 did suggest increased direct incorporation of glycine in microbial biomass, in particular in G+ bacteria, in an ecosystem subjected to elevated CO2. Warming decreased the concentration of PLFAs in general. The FACE CO2 was 13C-depleted (δ13C = 12.2‰) compared to ambient (δ13C = ∼−8‰), and this enabled observation of the integrated longer term responses of soil microorganisms to the FACE over one year. All together, the bacterial (and not fungal) utilization of glycine indicates substrate preference and resource partitioning in the microbial community, and therefore suggests a diversified response pattern to future changes in substrate availability and climatic factors. [ABSTRACT FROM AUTHOR]

Aims: Pulse labeling of crops using 13C is often employed to trace photosynthesized carbon (C) within crop-soil systems. However, few studies have compared the C distribution for different labeling periods. The overall aim of this study was to determine the length of the monitoring interval required after 13C-pulse labeling to quantify photosynthate C allocation into plant, soil and rhizosphere respiration pools for the entire growing season of maize ( Zea mays L.). Methods: Pot grown maize was pulse-labeled with 13CO 2 (98 at. %) at the beginning of emergence, elongation, heading and grainfilling growth stages. The routing of 13C into shoot and root biomass, soil CO 2 flux and soil organic carbon (SOC) pools was monitored for 27 days after 13C-pulse labeling at the beginning of each growth stage. Results: The majority of the 13C was recovered after 27 d in the maize shoots, i.e., 57 %, 53 %, 70 % and 80 %, at the emergence, elongation, heading, and grainfilling stages, respectively. More 13C was recovered in the root biomass at elongation (27 %) compared to the least at the grainfilling stage (3 %). The amount recovered in the soil was the smallest pool of 13C at emergence (2.3 %), elongation (3.8 %), heading and grainfilling (less than 2 %). The amount of 13C recovered in rhizosphere respiration, i.e. 13CO 2, was greatest at emergence (26 %), and similar at the elongation, heading and grainfilling stages (~16 %). Conclusions: At least 24 days is required to effectively monitor the recovery of 13C after pulse labeling with 13CO 2 for maize in plant and soil pools. The recovery of 13C differed between growth stages and corresponded to the changing metabolic requirements of the plant, which indicated labeling for the entire growth season would more accurately quantify the C budget in plant-soil system. [ABSTRACT FROM AUTHOR]

RATIONALE Globally, many drylands are experiencing the encroachment of woody vegetation into grasslands. These changes in ecosystem structure and processes can result in increased sediment and nutrient fluxes due to fluvial erosion. As these changes are often accompanied by a shift from C4 to C3 vegetation with characteristic δ13C values, stable isotope analysis provides a promising mechanism for tracing these fluxes. METHODS Input vegetation, surface sediment and fluvially eroded sediment samples were collected across two contrasting C4-C3 dryland vegetation transitions in New Mexico, USA. Isotope ratio mass spectrometric analyses were performed using a Carlo Erba NA2000 analyser interfaced to a SerCon 20-22 isotope ratio mass spectrometer to determine bulk δ13C values. RESULTS Stable isotope analyses of contemporary input vegetation and surface sediments over the monitored transitions showed significant differences ( p <0.05) in the bulk δ13C values of C4 Bouteloua sp. (grama) grassland, C3 Larrea tridentata (creosote) shrubland and C3 Pinus edulis/Juniperus monosperma (piñon-juniper) woodland sites. Significantly, this distinctive δ13C value was maintained in the bulk δ13C values of fluvially eroded sediment from each of the sites, with no significant variation between surface sediment and eroded sediment values. CONCLUSIONS The significant differences in bulk δ13C values between sites were dependent on vegetation input. Importantly, these values were robustly expressed in fluvially eroded sediments, suggesting that stable isotope analysis is suitable for tracing sediment fluxes. Due to the prevalent nature of these dryland vegetation transitions in the USA and globally, further development of stable isotope ratio mass spectrometry has provided a valuable tool for enhanced understanding of functional changes in these ecosystems. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Mechanisms to mitigate global climate change by sequestering carbon ( C) in different 'sinks' have been proposed as at least temporary measures. Of the major global C pools, terrestrial ecosystems hold the potential to capture and store substantially increased volumes of C in soil organic matter ( SOM) through changes in management that are also of benefit to the multitude of ecosystem services that soils provide. This potential can only be realized by determining the amount of SOM stored in soils now, with subsequent quantification of how this is affected by management strategies intended to increase SOM concentrations, and used in soil C models for the prediction of the roles of soils in future climate change. An apparently obvious method to increase C stocks in soils is to augment the soil C pools with the longest mean residence times ( MRT). Computer simulation models of soil C dynamics, e.g. RothC and Century, partition these refractory constituents into slow and passive pools with MRTs of centuries to millennia. This partitioning is assumed to reflect: (i) the average biomolecular properties of SOM in the pools with reference to their source in plant litter, (ii) the accessibility of the SOM to decomposer organisms or catalytic enzymes, or (iii) constraints imposed on decomposition by environmental conditions, including soil moisture and temperature. However, contemporary analytical approaches suggest that the chemical composition of these pools is not necessarily predictable because, despite considerable progress with understanding decomposition processes and the role of decomposer organisms, along with refinements in simulation models, little progress has been made in reconciling biochemical properties with the kinetically defined pools. In this review, we will explore how advances in quantitative analytical techniques have redefined the new understanding of SOM dynamics and how this is affecting the development and application of new modelling approaches to soil C. [ABSTRACT FROM AUTHOR]

The spatial distribution of alkaline phosphomonoesterase (ALP) activity in the rhizosphere and bulk soil of three plants (Zea mays, Medicago sativa, and Cyperus rotundus) grown in a karst soil (pH 8.27) was visualized using in situ soil zymography. According to the zymogram images, we identified and precisely collected soil samples from hotspots and non-hotspots of ALP activity, and then analyzed the phoD genes that encoded alkaline phosphomonoesterase and assessed the microbial community. The results showed that (1) the phoD abundance in the plant types varied and was highest in the alfalfa and lowest in the maize; (2) Proteobacteria dominated the phoD-harboring microbes in the rhizosphere and Actinobacteria dominated the phoD-harboring microbes in the bulk soil, and (3) the ALP activity was positively correlated with the relative abundance of the diazotrophic Azotobacter, but negatively correlated with the phoD gene abundance, microbial community richness, and diversity. By coupling zymography and microbial molecular approaches, we identified hotspots of enzymatic and microbial activity in rhizosphere soil and evaluated the relative contributions from potential active microorganisms. We found that the function of specific phoD-harboring microorganisms in these hotspots differed depending on the plant in the soil, which had implications for phosphorus (P) management in P-limited karst soils. The results also suggested that free-living N2-fixing bacteria (Azotobacter) might promote ALP activity, thereby emphasizing vital linkages between, and coupling of, the soil nutrient cycles. [ABSTRACT FROM AUTHOR]

Purpose : Nitrogen (N) transfer from white clover (Trifolium repens cv.) to ryegrass (Lolium perenne cv.) has the potential to meet ryegrass N requirements. This study aimed to quantify N transfer in a mixed pasture and investigate the influence of the microbial community and land management on N transfer. Methods: Split root 15N-labelling of clover quantified N transfer to ryegrass via exudation, microbial assimilation, decomposition, defoliation and soil biota. Incorporation into the microbial protein pool was determined using compound-specific 15N-stable isotope probing approaches. Results: N transfer to ryegrass and soil microbial protein in the model system was relatively small, with one-third arising from root exudation. N transfer to ryegrass increased with no microbial competition but soil microbes also increased N transfer via shoot decomposition. Addition of mycorrhizal fungi did not alter N transfer, due to the source-sink nature of this pathway, whilst weevil grazing on roots decreased microbial N transfer. N transfer was bidirectional, and comparable on a short-term scale. Conclusions: N transfer was low in a model young pasture established from soil from a permanent grassland with long-term N fertilisation. Root exudation and decomposition were major N transfer pathways. N transfer was influenced by soil biota (weevils, mycorrhizae) and land management (e.g. grazing). Previous land management and the role of the microbial community in N transfer must be considered when determining the potential for N transfer to ryegrass. [ABSTRACT FROM AUTHOR]

The extent to which soil erosion is a net source or sink of carbon globally remains unresolved but has the potential to play a key role in determining the magnitude of CO2 emissions from land‐use change in rapidly eroding landscapes. The effects of soil erosion on carbon storage in low‐input agricultural systems, in acknowledged global soil erosion hotspots in developing countries, are especially poorly understood. Working in one such hotspot, the Indian Himalaya, we measured and modelled field‐scale soil budgets, to quantify erosion‐induced changes in soil carbon storage. In addition, we used long‐term (1‐year) incubations of separate and mixed soil horizons to better understand the mechanisms controlling erosion‐induced changes in soil carbon cycling. We demonstrate that high rates of soil erosion did not promote a net carbon loss to the atmosphere at the field scale. Furthermore, our experiments showed that rates of decomposition in the organic matter‐rich subsoil layers in depositional areas were lower per unit of soil carbon than from other landscape positions; however, these rates could be increased by mixing with topsoils. The results indicate that, the burial of soil carbon, and separation from fresh carbon inputs, led to reduced rates of decomposition offsetting potential carbon losses during soil erosion and transport within the cultivated fields. We conclude that the high rates of erosion experienced in these Himalayan soils do not, in isolation, drive substantial emissions of organic carbon, and there is the potential to promote carbon storage through sustainable agricultural practice. [ABSTRACT FROM AUTHOR]

Agricultural grass cultivars bred for increased forage yield commonly have extensive root systems. As roots are an important input of organic matter into the soil, it follows that such cultivars could lead to important increases in soil organic carbon (SOC), but this, and the mechanisms involved, are poorly understood with little empirical field evidence. We assessed the effect of two cultivars, Lolium perenne L. cv. "AberMagic" and L. perenne L. × Festuca pratensis Huds. cv. "Prior", in comparison with mixed‐species permanent pasture ("Pasture") in a field experiment on temperate alluvial soil in the southwest UK. Root and SOC stocks, and specific plant‐derived lipids as mechanistic biomarkers for shoot and root inputs of C, were measured on intact 1‐m volumetric soil cores collected on four dates in 2013–2015. Total grass yields were greater for both grass cultivars (40–43 Mg ha−1) than Pasture (39 Mg ha−1), and by 2015 root stocks in the upper 0.1 m were significantly greater by more than 4.7 Mg ha−1. At 0.1–0.3 m depth, SOC stocks (per 0.1‐m depth) were significantly greater under the two grass cultivars (24–50 Mg ha−1) compared to Pasture (18–32 Mg ha−1). In the full 1‐m profile, mean SOC stocks were 137, 133 and 110 Mg ha−1 for AberMagic, Prior and Pasture, respectively, matching root biomass distribution. Odd‐chain n‐alkane concentrations were significantly greater for shoots than roots (274 vs. 64 mg kg−1, respectively), and roots had significantly greater concentrations than shoots of even‐chain hydroxy fatty acids (1829 vs. 305 mg kg−1, respectively) and diacids (317 vs. 93 mg kg−1, respectively). This confirmed lipids as candidate biomarkers for distinguishing shoot and root inputs into the soil, with roots being the dominant source of SOC. Based on the observations of increased forage yield and SOC stock, high‐yielding forage grass cultivars can contribute to future strategies for climate‐smart agriculture in grassland‐dominated temperate regions. Highlights: Selected root traits for increased depth, density and diameter may increase SOC in grassland.The effect of two high‐yielding forage grass cultivars were assessed in a field trial.Fast‐growing, high‐yielding cultivars enhanced root and SOC stocks compared to typical pasture.Lipid biomarkers confirmed that root inputs were the predominant C input to soil. [ABSTRACT FROM AUTHOR]

Purpose: Plants growing in the soils of karst forests associate with arbuscular mycorrhizae (AM) or ectomycorrhizae (ECM) to acquire nutrients. We researched how these different mycorrhizal associations affect rhizosphere soil nutrient economy in these calcareous soils. Methods: Bulk and rhizosphere soils were sampled beneath 25 AM and 9 ECM plants growing in primary forests at the Puding Karst Critical Zone Observatory. Nutrient contents and potential enzyme activities were analyzed to test the effect of different types of mycorrhizal association on rhizosphere soil nitrogen (N) and phosphorus (P) economies. Results: The contents of nitrate-N and available-P were markedly lower in the rhizospheres of ECM plants compared to AM plants. Ectomycorrhizal plants promoted relatively greater investment in N-acquisition enzymes, in contrast, AM plants caused relatively greater investment in P-acquisition enzymes. The decreased pH in the rhizospheres of AM plants likely promoted the greater P availability. Conclusion: Our results revealed how plants that form contrasting mycorrhizal associations have fundamentally different effects on rhizospheric nutrient economies in the low fertility karst soils of southwest China. Differentiation in N- and P-acquisition capacity of these plants have implications for species coexistence and the high levels of plant biodiversity observed in these forests. [ABSTRACT FROM AUTHOR]

Current consensus on global climate change predicts warming trends with more pronounced temperature changes in winter than summer in the Northern Hemisphere at high latitudes. Moderate increases in soil temperature are generally related to faster rates of soil organic carbon (SOC) decomposition in Northern ecosystems, but there is evidence that SOC stocks have remained remarkably stable or even increased on the Tibetan Plateau under these conditions. This intriguing observation points to altered soil microbial mediation of carbon‐cycling feedbacks in this region that might be related to seasonal warming. This study investigated the unexplained SOC stabilization observed on the Tibetan Plateau by quantifying microbial responses to experimental seasonal warming in a typical alpine meadow. Ecosystem respiration was reduced by 17%–38% under winter warming compared with year‐round warming or no warming and coincided with decreased abundances of fungi and functional genes that control labile and stable organic carbon decomposition. Compared with year‐round warming, winter warming slowed macroaggregate turnover rates by 1.6 times, increased fine intra‐aggregate particulate organic matter content by 75%, and increased carbon stabilized in microaggregates within stable macroaggregates by 56%. Larger bacterial "necromass" (amino sugars) concentrations in soil under winter warming coincided with a 12% increase in carboxyl‐C. These results indicate the enhanced physical preservation of SOC under winter warming and emphasize the role of soil microorganisms in aggregate life cycles. In summary, the divergent responses of SOC persistence in soils exposed to winter warming compared to year‐round warming are explained by the slowing of microbial decomposition but increasing physical protection of microbially derived organic compounds. Consequently, the soil microbial response to winter warming on the Tibetan Plateau may cause negative feedbacks to global climate change and should be considered in Earth system models. [ABSTRACT FROM AUTHOR]

This chapter reviews contributions made to agricultural and environmental science and practice from research on temperate grassland carried out from 1982 to present at Rothamsted Research's North Wyke Research Station, Devon, UK. It describes the evolution of the research program and demonstrates the importance of sustained, interdisciplinary, and collaborative research. North Wyke has maintained a clear research focus, alongside an ability to adapt to changing grassland and environmental research needs and funding sources, and despite having changed affiliations on several occasions. The substantial contribution to agricultural and environmental science arising from the research station has influenced and continues to influence farm practice, research, and policy nationally and internationally. Some key topics have included nutrient cycling, farm waste management, gaseous emissions, biodiversity, grazing management, animal production (meat and milk), and forage quality. Currently, North Wyke Research Station is leading the way on taking increasingly holistic approaches to researching more efficient, sustainable approaches to grazing-livestock agricultural production. This involves the use of world-leading, facilities such as the North Wyke Farm Platform, comprising three farmlets, designed to test the productivity and environmental sustainability of contrasting temperate grassland beef and sheep systems. Future perspectives highlight key challenges facing the agricultural industry including climate change mitigation and adaptation, and the growing world population. Opportunities exist to tackle these challenges through technological advances, but also through increased integration of agricultural, environmental, economic and social research. North Wyke Research Station provides an example of a research facility where such challenges can be addressed. [ABSTRACT FROM AUTHOR]

Karst topography covers more than 1/3 of the People's Republic of China in area. The porous, fissured, and soluble nature of the underlying karst bedrock (primarily dolomite and limestone) leads to the formation of underground drainage systems. Karst conduit networks dominate this system, and rainfall takes a crucial role on water cycle at China karst area. Nitrogen loss from the karst system is of particular concern, with regard to nutrient use efficiency as well as water quality, as much of the karst system, including steeply sloping terrain, is used for intensive agriculture. We use simulated rainfall experiments to determine the relationship between rainfall and nitrogen loss at typical karst slope land and then estimate nitrogen loss from the karst soil. The results show that both surface runoff and subsurface runoff have a significant linear correlation with rainfall at all studied sites. Subsurface runoff is larger than surface runoff at two karst sites, while the opposite is true at the non-karst site. Exponential function satisfactorily described the correlation between rainfall and nitrogen concentrations in runoff. Nitrates accounted for 60%-95% of the dissolved nitrogen loss (DN, an index of N-loss in this research). The estimated annual N-loss load varies between 1.05 and 1.67 Tg N/year in the whole karst regions of China from 1961 to 2014. Approximately, 90% of the N-loss load occurred during the wet season, and 90% of that passed through the subsurface. Understanding the processes and estimating N-loss is highly valuable in determining long-term soil security and sustainability in karst regions. [ABSTRACT FROM AUTHOR]

Rising global temperatures may increase the rates of soil organic matter decomposition by heterotrophic microorganisms, potentially accelerating climate change further by releasing additional carbon dioxide (CO2) to the atmosphere. However, the possibility that microbial community responses to prolonged warming may modify the temperature sensitivity of soil respiration creates large uncertainty in the strength of this positive feedback. Both compensatory responses (decreasing temperature sensitivity of soil respiration in the long-term) and enhancing responses (increasing temperature sensitivity) have been reported, but the mechanisms underlying these responses are poorly understood. In this study, microbial biomass, community structure and the activities of dehydrogenase and ß-glucosidase enzymes were determined for 18 soils that had previously demonstrated either no response or varying magnitude of enhancing or compensatory responses of temperature sensitivity of heterotrophic microbial respiration to prolonged cooling. The soil cooling approach, in contrast to warming experiments, discriminates between microbial community responses and the consequences of substrate depletion, by minimising changes in substrate availability. The initial microbial community composition, determined by molecular analysis of soils showing contrasting respiration responses to cooling, provided evidence that the magnitude of enhancing responses was partly related to microbial community composition. There was also evidence that higher relative abundance of saprophytic Basidiomycota may explain the compensatory response observed in one soil, but neither microbial biomass nor enzymatic capacity were significantly affected by cooling. Our findings emphasise the key importance of soil microbial community responses for feedbacks to global change, but also highlight important areas where our understanding remains limited. [ABSTRACT FROM AUTHOR]

A Correction to this paper has been published: https://doi.org/10.1007/s11104-021-05032-6 [ABSTRACT FROM AUTHOR]

Antarctica's extreme environment and geographical isolation offers a useful platform for testing the relative roles of environmental selection and dispersal barriers influencing fungal communities. The former process should lead to convergence in community composition with other cold environments, such as those in the Arctic. Alternatively, dispersal limitations should minimise similarity between Antarctica and distant northern landmasses. Using high-throughput sequencing, we show that Antarctica shares significantly more fungi with the Arctic, and more fungi display a bipolar distribution, than would be expected in the absence of environmental filtering. In contrast to temperate and tropical regions, there is relatively little endemism, and a strongly bimodal distribution of range sizes. Increasing southerly latitude is associated with lower endemism and communities increasingly dominated by fungi with widespread ranges. These results suggest that micro-organisms with well-developed dispersal capabilities can inhabit opposite poles of the Earth, and dominate extreme environments over specialised local species. [ABSTRACT FROM AUTHOR]

Soils store about four times as much carbon as plant biomass, and soil microbial respiration releases about 60 petagrams of carbon per year to the atmosphere as carbon dioxide. Short-term experiments have shown that soil microbial respiration increases exponentially with temperature. This information has been incorporated into soil carbon and Earth-system models, which suggest that warming-induced increases in carbon dioxide release from soils represent an important positive feedback loop that could influence twenty-first-century climate change. The magnitude of this feedback remains uncertain, however, not least because the response of soil microbial communities to changing temperatures has the potential to either decrease or increase warming-induced carbon losses substantially. Here we collect soils from different ecosystems along a climate gradient from the Arctic to the Amazon and investigate how microbial community-level responses control the temperature sensitivity of soil respiration. We find that the microbial community-level response more often enhances than reduces the mid- to long-term (90 days) temperature sensitivity of respiration. Furthermore, the strongest enhancing responses were observed in soils with high carbon-to-nitrogen ratios and in soils from cold climatic regions. After 90 days, microbial community responses increased the temperature sensitivity of respiration in high-latitude soils by a factor of 1.4 compared to the instantaneous temperature response. This suggests that the substantial carbon stores in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted. [ABSTRACT FROM AUTHOR]

Today, insular Southeast Asia is important for both its remarkably rich biodiversity and globally significant roles in atmospheric and oceanic circulation. Despite the fundamental importance of environmental history for diversity and conservation, there is little primary evidence concerning the nature of vegetation in north equatorial Southeast Asia during the Last Glacial Period (LGP). As a result, even the general distribution of vegetation during the Last Glacial Maximum is debated. Here we show, using the stable carbon isotope composition of ancient cave guano profiles, that there was a substantial forest contraction during the LGP on both peninsular Malaysia and Palawan, while rainforest was maintained in northern Borneo. These results directly support rainforest "refugia" hypotheses and provide evidence that environmental barriers likely reduced genetic mixing between Borneo and Sumatra flora and fauna. Moreover, it sheds light on possible early human dispersal events. [ABSTRACT FROM AUTHOR]

The incorporation of new sophisticated phenotyping technologies within a crop improvement program allows for a plant breeding strategy that can include selections for major root traits previously inaccessible due to the challenges in their phenotype assessment. High‐throughput precision phenotyping technology is employed to evaluate root ontogeny and progressive changes to root architecture of both novel amphiploid and introgression lines of Festulolium over four consecutive months of the growing season and these compared under the same time frame to that of closely related perennial ryegrass (L. perenne) varieties. Root imaging using conventional photography and assembled multiple merged images was used to compare frequencies in root number, their distribution within 0–20 and 20–40 cm depths within soil columns, and progressive changes over time. The Festulolium hybrids had more extensive root systems in comparison with L. perenne, and this was especially evident at depth. It was shown that the acquisition of extensive root systems in Festulolium hybrids was not dependent on the presence of an entire Festuca genome. On the contrary, the most pronounced effect on root development within the four Festulolium populations studied was observed in the introgression line Bx509, where a single small genome sequence from F. arundinacea had been previously transferred onto its homoeologous site on the long arm of chromosome 3 of an otherwise complete L. perenne genome. This demonstrates that a targeted introgression‐breeding approach may be sufficient to confer a significant improvement in the root morphology in Lolium without a significant compromise to its genome integrity. The forage production of Bx509 was either higher (months 1–3) or equivalent to (month 4) that of its L. perenne parent control demonstrating that the enhanced root development achieved by the introgression line was without compromise to its agronomic performance. The manuscript describes the use of precision image capture technologies to measure root ontogeny of four diverse Festulolium populations and relevant perennial ryegrass controls. It describes changes over a 4‐month period of the growing season and root development at two soil depths. The paper relates changes in root design in terms of benefits to ecosystem services and to combat climate change. [ABSTRACT FROM AUTHOR]