Soil Science最新文献

{"title":"Effects of environmental factors on the influence of tillage conversion on saturated soil hydraulic conductivity obtained with different methodologies: a global meta-analysis","authors":"K. Liao, Juan Feng, X. Lai, Q. Zhu","doi":"10.5194/soil-8-309-2022","DOIUrl":"https://doi.org/10.5194/soil-8-309-2022","url":null,"abstract":"Abstract. The saturated hydraulic conductivity (Ksat) is a key\u0000soil hydraulic property governing agricultural production. However, the influence of the conversion from the conventional tillage (CT) to conservation tillage (CS; including no tillage, NT, and reduced tillage, RT) on the Ksat of soils is not well understood and still debated. In this study, we applied a global meta-analysis method to synthesize 227 paired\u0000observations for soil Ksat from 69 published studies and investigated factors influencing the effects of conversion to CS on Ksat. Results showed that soil layer, conservation tillage type, soil texture type, and cropping system management did not have significant effects on the influence of conversion to CS on Ksat. When the Ksat was measured by the rainfall simulator, the conversion to CS significantly (p<0.05) increased the\u0000surface and subsurface soil Ksat by 41.7 % and 36.9 %, respectively. In addition, the subsurface Ksat also tended to increase under CS practices when the Ksat was measured by a tension disc infiltrometer. However, when the Ksat was measured by a hood infiltrometer, ring infiltrometer, constant/falling head, and Guelph permeameter, the conversion to CS had no significant effects on the Ksat. It is observed that, when the conversion period was less than 15 years, the Ksat under CS showed a greater increase for a longer conversion period. Climatic and topographic factors, including the mean annual temperature (MAT) and the mean annual precipitation (MAP), were statistically related to the responses of Ksat to tillage conversion at the global scale. Quadratic polynomials can describe the relationships between them. These findings suggested that quantifying the effects of tillage conversion on soil Ksat needed to\u0000consider experimental conditions, especially the measurement technique and conversion period.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79450072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lower functional redundancy in “narrow” than “broad” functions in global soil metagenomics","authors":"Huaihai Chen, Kayan Ma, Yu Huang, Qi Fu, Ying Qiu, Jiajiang Lin, C. Schadt, Hao Chen","doi":"10.5194/soil-8-297-2022","DOIUrl":"https://doi.org/10.5194/soil-8-297-2022","url":null,"abstract":"Abstract. Understanding the relationship between soil microbial taxonomic compositions\u0000and functional profiles is essential for predicting ecosystem functions\u0000under various environmental disturbances. However, even though microbial\u0000communities are sensitive to disturbance, ecosystem functions remain\u0000relatively stable, as soil microbes are likely to be functionally redundant.\u0000Microbial functional redundancy may be more associated with “broad”\u0000functions carried out by a wide range of microbes than with “narrow”\u0000functions in which specific microorganisms specialize. Thus, a comprehensive\u0000study to evaluate how microbial taxonomic compositions correlate with\u0000broad and narrow functional profiles is necessary. Here, we\u0000evaluated soil metagenomes worldwide to assess whether functional and\u0000taxonomic diversities differ significantly between the five broad and\u0000the five narrow functions that we chose. Our results revealed that,\u0000compared with the five broad functions, soil microbes capable of\u0000performing the five narrow functions were more taxonomically diverse,\u0000and thus their functional diversity was more dependent on taxonomic\u0000diversity, implying lower levels of functional redundancy in narrow\u0000functions. Co-occurrence networks indicated that microorganisms conducting\u0000broad functions were positively related, but microbes specializing\u0000in narrow functions were interacting mostly negatively. Our study provides\u0000strong evidence to support our hypothesis that functional redundancy is\u0000significantly different between broad and narrow functions in soil\u0000microbes, as the association of functional diversity with taxonomy was\u0000greater in the five narrow than in the five broad functions.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89926591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Land use impact on carbon mineralization in well aerated soils is mainly explained by variations of particulate organic matter rather than of soil structure","authors":"S. Schlüter, Tim Roussety, Lena Rohe, V. Guliyev, E. Blagodatskaya, Thomas Reitz","doi":"10.5194/soil-8-253-2022","DOIUrl":"https://doi.org/10.5194/soil-8-253-2022","url":null,"abstract":"Abstract. Land use is known to exert a dominant impact on a range of\u0000essential soil functions like water retention, carbon sequestration, organic\u0000matter cycling and plant growth. At the same time, land use management is\u0000known to have a strong influence on soil structure, e.g., through\u0000bioturbation, tillage and compaction. However, it is often unclear whether\u0000the differences in soil structure are the actual cause of the differences in soil\u0000functions or if they only co-occur. This impact of land use (conventional and organic farming, intensive and\u0000extensive meadow, extensive pasture) on the relationship between soil\u0000structure and short-term carbon mineralization was investigated at the\u0000Global Change Exploratory Facility, in Bad Lauchstädt, Germany. Intact\u0000topsoil cores (upper 10 cm, n=75) were sampled from all land use types at\u0000the early growing season. Soil structure and microbial activity were\u0000measured using X-ray-computed tomography and respirometry, respectively. Differences in microstructural properties between land uses were small in\u0000comparison to the variation within land uses. The most striking difference\u0000between land uses was larger macropore diameters in grassland soils due to\u0000the presence of large biopores that are periodically destroyed in croplands.\u0000Grasslands had larger amounts of particulate organic matter (POM), including\u0000root biomass, and also greater microbial activity than croplands, both in\u0000terms of basal respiration and rate of carbon mineralization during growth.\u0000Basal respiration among soil cores varied by more than 1 order of\u0000magnitude (0.08–1.42 µg CO2-C h−1 g−1 soil) and was\u0000best explained by POM mass (R2=0.53, p<0.001).\u0000Predictive power was only slightly improved by considering all bulk, microstructure\u0000and microbial properties jointly. The predictive power of image-derived\u0000microstructural properties was low, because aeration did not limit carbon\u0000mineralization and was sustained by pores smaller than the image resolution\u0000limit (<30 µm). The frequently postulated dependency of\u0000basal respiration on soil moisture was not evident even though some cores\u0000were apparently water limited, as it was likely disguised by the\u0000co-limitation of POM mass. This finding was interpreted in regards to the microbial\u0000hotspots which form on decomposing plant residues and which are decoupled\u0000from water limitation in bulk soil. The rate of glucose mineralization\u0000during growth was explained well by substrate-induced respiration\u0000(R2=0.84) prior to growth, which in turn correlated with total\u0000microbial biomass, basal respiration and POM mass, and was not affected by pore\u0000metrics. These findings stress that soil structure had little relevance in predicting\u0000carbon mineralization in well-aerated soil, as mineralization appeared to by\u0000predominantly driven by the decomposition of plant residues in intact soil.\u0000Land use therefore affects carbon mineralization in well-aerated soil mainly\u0000in the amount and quality of labile carbon.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88254497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term impact of cover crop and reduced disturbance tillage on soil pore size distribution and soil water storage","authors":"S. Araya, Jeffrey P. Mitchell, J. Hopmans, T. Ghezzehei","doi":"10.5194/soil-8-177-2022","DOIUrl":"https://doi.org/10.5194/soil-8-177-2022","url":null,"abstract":"Abstract. We studied the long-term impact of contrasting tillage\u0000and cover cropping systems on soil structure and hydraulic properties.\u0000Complete water retention and conductivity curves for the top (0–5 cm) and\u0000subsurface (20–25 cm) soils were characterized and contrasted. Dynamic\u0000water storage and retention were evaluated using numerical simulations in\u0000HYDRUS-2D software. Compared with standard-till (ST) and no-cover-crop (NO)\u0000systems, soils under no-till (NT) and cover cropping (CC) systems showed\u0000improved soil structure in terms of pore size distribution (PSD). Changes in\u0000hydraulic conductivity (K) under these systems led to an increased infiltration\u0000rate and water retention. However, NT and CC plots had lower water content\u0000at field capacity (33 kPa suction) and lower plant-available water (PAW)\u0000compared with ST and NO plots. Numerical simulations, however, showed that NT\u0000and CC plots have higher water storage (albeit marginal in magnitude) and\u0000water availability following irrigation. Because the numerical simulations\u0000considered retention and conductivity functions simultaneously and\u0000dynamically through time, they allow the capture of hydraulic states that\u0000are arguably more relevant to crops. The study concludes that the long-term\u0000practices of NT and CC systems were beneficial in terms of changes to the\u0000PSD. NT and CC systems also marginally improved soil water\u0000conductivity and storage at the plot scale.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78123282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inclusion of biochar in a C dynamics model based on observations from an 8-year field experiment","authors":"Roberta Pulcher, E. Balugani, M. Ventura, N. Greggio, D. Marazza","doi":"10.5194/soil-8-199-2022","DOIUrl":"https://doi.org/10.5194/soil-8-199-2022","url":null,"abstract":"Abstract. Biochar production and application as soil amendment is a\u0000promising carbon (C)-negative technology to increase soil C sequestration\u0000and mitigate climate change. However, there is a lack of knowledge about\u0000biochar degradation rate in soil and its effects on native soil organic\u0000carbon (SOC), mainly due to the absence of long-term experiments performed\u0000in field conditions. The aim of this work was to investigate the long-term\u0000degradation rate of biochar in an 8-year field experiment in a poplar\u0000short-rotation coppice plantation in Piedmont (Italy), and to modify the\u0000RothC model to assess and predict how biochar influences soil C dynamics.\u0000The RothC model was modified by including two biochar pools, labile (4 %\u0000of the total biochar mass) and recalcitrant (96 %), and the priming effect\u0000of biochar on SOC. The model was calibrated and validated using data from\u0000the field experiment. The results confirm that biochar degradation can be\u0000faster in field conditions in comparison to laboratory experiments;\u0000nevertheless, it can contribute to a substantial increase in the soil C stock\u0000in the long term. Moreover, this study shows that the modified RothC model\u0000was able to simulate the dynamics of biochar and SOC degradation in soils in\u0000field conditions in the long term, at least in the specific conditions\u0000examined.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"140 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86664212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Content of soil organic carbon and labile fractions depend on local combinations of mineral-phase characteristics","authors":"M. Ortner, M. Seidel, Sebastian Semella, T. Udelhoven, Michael Vohland, S. Thiele-Bruhn","doi":"10.5194/soil-8-113-2022","DOIUrl":"https://doi.org/10.5194/soil-8-113-2022","url":null,"abstract":"Abstract. Soil organic matter (SOM) is an indispensable component of\u0000terrestrial ecosystems. Soil organic carbon (SOC) dynamics are influenced by\u0000a number of well-known abiotic factors such as clay content, soil pH, or pedogenic oxides. These parameters interact with each other and vary in\u0000their influence on SOC depending on local conditions. To investigate the\u0000latter, the dependence of SOC accumulation on parameters and parameter\u0000combinations was statistically assessed that vary on a local scale depending\u0000on parent material, soil texture class, and land use. To this end, topsoils were sampled from arable and grassland sites in south-western Germany in four regions with different soil parent material. Principal component analysis\u0000(PCA) revealed a distinct clustering of data according to parent material\u0000and soil texture that varied largely between the local sampling regions,\u0000while land use explained PCA results only to a small extent. The PCA\u0000clusters were differentiated into total clusters that contain the entire\u0000dataset or major proportions of it and local clusters representing only a\u0000smaller part of the dataset. All clusters were analysed for the relationships between SOC concentrations (SOC %) and mineral-phase parameters in order to assess specific parameter combinations explaining SOC\u0000and its labile fractions hot water-extractable C (HWEC) and microbial biomass C (MBC). Analyses were focused on soil parameters that are known as possible predictors for the occurrence and stabilization of SOC (e.g. fine\u0000silt plus clay and pedogenic oxides). Regarding the total clusters, we found\u0000significant relationships, by bivariate models, between SOC, its labile\u0000fractions HWEC and MBC, and the applied predictors. However, partly low explained variances indicated the limited suitability of bivariate models. Hence, mixed-effect models were used to identify specific parameter combinations that significantly explain SOC and its labile fractions of the different\u0000clusters. Comparing measured and mixed-effect-model-predicted SOC values revealed acceptable to very good regression coefficients (R2=0.41–0.91)\u0000and low to acceptable root mean square error (RMSE = 0.20 %–0.42 %).\u0000Thereby, the predictors and predictor combinations clearly differed between\u0000models obtained for the whole dataset and the different cluster groups. At a local scale, site-specific combinations of parameters explained the variability of organic carbon notably better, while the application of total\u0000models to local clusters resulted in less explained variance and a higher\u0000RMSE. Independently of that, the explained variance by marginal fixed effects decreased in the order SOC > HWEC > MBC,\u0000showing that labile fractions depend less on soil properties but presumably\u0000more on processes such as organic carbon input and turnover in soil.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"1212 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76127813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rhizodeposition efficiency of pearl millet genotypes assessed on a short growing period by carbon isotopes (δ13C and F14C)","authors":"P. M. S. Ndour, C. Hatté, W. Achouak, T. Heulin, L. Cournac","doi":"10.5194/soil-8-49-2022","DOIUrl":"https://doi.org/10.5194/soil-8-49-2022","url":null,"abstract":"Abstract. Rhizosheath size varies significantly with crop genotype,\u0000and root exudation is one among its driving factors. Unravelling the\u0000relationships between rhizosheath formation, root exudation and soil carbon\u0000dynamics may bring interesting perspectives in terms of crop breeding\u0000towards sustainable agriculture. Here we grew four pearl millet (C4\u0000plant type: δ13C of −12.8 ‰, F14C = 1.012) inbred lines showing contrasting rhizosheath sizes in a C3 soil\u0000type (organic matter with δ13C of −22.3 ‰,\u0000F14C = 1.045). We sampled the root-adhering soil (RAS) and bulk soil\u0000after 28 d of growth under a semi-controlled condition. The soil organic carbon (SOC) content and δ13C and F14C of soil samples were measured and the plant-derived C amount and Clost / Cnew ratio in the RAS were calculated. The results showed a significant increase in δ13C in the RAS of the four pearl millet lines compared to the control\u0000soil, suggesting that this approach was able to detect plant C input into the soil at an early stage of pearl millet growth. The concentration of\u0000plant-derived C in the RAS did not vary significantly between pearl millet\u0000lines, but the absolute amount of plant-derived C varied significantly when\u0000we considered the RAS mass of these different lines. Using a conceptual\u0000model and data from the two carbon isotopes' measurements, we evidenced a priming effect for all pearl millet lines. Importantly, the priming effect amplitude (Clost / Cnew ratio) was higher for the small rhizosheath\u0000(low-aggregation) line than for the large rhizosheath (high-aggregation)\u0000ones, indicating a better C sequestration potential of the latter.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"118 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79404683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergy between compost and cover crops in a Mediterranean row crop system leads to increased subsoil carbon storage","authors":"D. Rath, N. Bogie, L. Deiss, S. Parikh, D. Wang, S. Ying, N. Tautges, A. Berhe, T. Ghezzehei, K. Scow","doi":"10.5194/soil-8-59-2022","DOIUrl":"https://doi.org/10.5194/soil-8-59-2022","url":null,"abstract":"Abstract. Subsoil carbon (C) stocks are a prime target for efforts to increase soil C storage for climate change mitigation. However, subsoil C dynamics are not well understood, especially in soils under long-term intensive agricultural management. We compared subsoil C storage and soil organic matter (SOM) composition in tomato–corn rotations after 25 years of differing C and nutrient management in the California Central Valley: CONV (mineral fertilizer), CONV+WCC (mineral fertilizer and cover crops), and ORG (composted poultry manure and cover crops). The cover crop mix used in these systems is a mix of oat (Avena sativa L.), faba bean (Vicia faba L.), and hairy vetch (Vicia villosa Roth). Our results showed a ∼19 Mg ha−1 increase in soil organic C (SOC) stocks down to 1 m under ORG systems, no significant SOC increases under CONV+WCC or CONV systems, and an increased abundance of carboxyl-rich C in the subsoil (60–100 cm) horizons of ORG and CONV+WCC systems. Our results show the potential for increased subsoil C storage with compost and cover crop amendments in tilled agricultural systems and identify potential pathways for increasing C transport and storage in subsoil layers.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81051284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phosphorus dynamics during early soil development in a cold desert: insights from oxygen isotopes in phosphate","authors":"Z. Frkova, C. Pistocchi, Y. Vystavna, K. Čapková, J. Doležal, F. Tamburini","doi":"10.5194/soil-8-1-2022","DOIUrl":"https://doi.org/10.5194/soil-8-1-2022","url":null,"abstract":"Abstract. At the early stages of pedogenesis, the dynamics of phosphorus (P)\u0000in soils are controlled by microbial communities, the physicochemical\u0000properties of the soil and the environmental conditions. While various\u0000microorganisms involved in carrying out biogeochemical processes have been\u0000identified, little is known about the actual contribution of microbial\u0000processes, such as organic P hydrolysis and microbial P turnover, to P\u0000cycling. We thus focused on processes driven by microbes and how they affect\u0000the size and cycling of organic and inorganic soil P pools along a soil\u0000chronosequence in the Chamser Kangri glacier forefield (Western Himalayas).\u0000The rapid retreat of the glacier allowed us to study the early stages of\u0000soil formation under a cold arid climate. Biological P transformations were\u0000studied with the help of the isotopic composition of oxygen (O) in phosphate\u0000(δ18OP) coupled to sequential P fractionation performed on\u0000soil samples (0–5 cm depth) from four sites of different age spanning 0 to\u0000100–150 years. The P bound to Ca, i.e., 1 M HCl-extractable P,\u0000still represented 95 % of the total P stock after approximately 100 years of soil\u0000development. Its isotopic composition was similar to the parent material at\u0000the most developed site. Primary phosphate minerals, possibly apatite,\u0000mostly comprised this pool. The δ18OP of the available P\u0000and the NaOH-extractable inorganic P instead differed from that of the\u0000parent material, suggesting that these pools underwent biological turnover.\u0000The δ18OP of the available P was mostly controlled by the\u0000microbial P, suggesting fast exchanges occurred between these two pools\u0000possibly fostered by repeated freezing–thawing and drying–rewetting cycles.\u0000The release of P from organic P becomes increasingly important with soil\u0000age, constituting one-third of the P flux to available P at the oldest site.\u0000Accordingly, the lighter isotopic composition of the P bound to Fe and Al\u0000oxides at the oldest site indicated that this pool contained phosphate\u0000released by organic P mineralization. Compared to previous studies on early\u0000pedogenesis under alpine or cold climate, our findings suggest a much slower\u0000decrease of the P-bearing primary minerals during the first 100 years of\u0000soil development under extreme conditions. However, they provide evidence\u0000that, by driving short-term P dynamics, microbes play an important role in\u0000controlling the redistribution of primary P into inorganic and organic soil\u0000P pools.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82364321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Upper Bound and Linear-Space Queries on the LZ-End Parsing.","authors":"Dominik Kempa, Barna Saha","doi":"10.1137/1.9781611977073.111","DOIUrl":"10.1137/1.9781611977073.111","url":null,"abstract":"<p><p>Lempel-Ziv (LZ77) compression is the most commonly used lossless compression algorithm. The basic idea is to greedily break the input string into blocks (called \"phrases\"), every time forming as a phrase the longest prefix of the unprocessed part that has an earlier occurrence. In 2010, Kreft and Navarro introduced a variant of LZ77 called LZ-End, that additionally requires the previous occurrence of each phrase to end at the boundary of an already existing phrase. Due to its excellent practical performance as a compression algorithm and a compressed index, they conjectured that it achieves a compression that can be provably upper-bounded in terms of the LZ77 size. Despite the recent progress in understanding such relation for other compression algorithms (e.g., the run-length encoded Burrows-Wheeler transform), no such result is known for LZ-End. We prove that for any string of length <math><mi>n</mi></math>, the number <math><msub><mrow><mi>z</mi></mrow><mrow><mi>e</mi></mrow></msub></math> of phrases in the LZ-End parsing satisfies <math><msub><mrow><mi>z</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>=</mo><mi>𝒪</mi><mfenced><mrow><mi>z</mi><msup><mrow><mi>l</mi><mi>o</mi><mi>g</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>⁡</mo><mi>n</mi></mrow></mfenced></math>, where <math><mi>z</mi></math> is the number of phrases in the LZ77 parsing. This is the first non-trivial upper bound on the size of LZ-End parsing in terms of LZ77, and it puts LZ-End among the strongest dictionary compressors. Using our techniques we also derive bounds for other variants of LZ-End and with respect to other compression measures. Our second contribution is a data structure that implements random access queries to the text in <math><mi>𝒪</mi><mfenced><mrow><msub><mrow><mi>z</mi></mrow><mrow><mi>e</mi></mrow></msub></mrow></mfenced></math> space and <math><mi>𝒪</mi><mo>(</mo><mi>p</mi><mi>o</mi><mi>l</mi><mi>y</mi><mi>l</mi><mi>o</mi><mi>g</mi><mo>⁡</mo><mi>n</mi><mo>)</mo></math> time. This is the first linear-size structure on LZ-End that efficiently implements such queries. All previous data structures either incur a logarithmic penalty in the space or have slow queries. We also show how to extend these techniques to support longest-common-extension (LCE) queries.</p>","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"144 1","pages":"2847-2866"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11145761/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83791180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}