Seasonal dynamics of soil mineral nitrogen pools and nitrogen mineralization rate in different forests in subtropical China

doi:10.13287/j.1001-9332.201703.036

Abstract

Abstract: We conducted an in situ incubation experiment to determine soil mineral N (NH₄⁺-N and NO₃^--N) concentrations and soil net N mineralization rates (net ammonification rate and net nitrification rate) using close-top PVC tubes in three adjacent forests (natural forest, Castanopsis kawakamii and Cunninghamia lanceolata plantation) from September 2014 to August 2015 in subtropical China, investigating the effects of forest type and season on soil inorganic N concentrations and soil net N mineralization rates. Results showed that soil NO₃^--N was the dominant form in mi-neral N pool in all three forests, and the proportion of NO₃^--N to soil inorganic N content ranged from 55.1% to 87.5% and from 56.1% to 79.1% in natural forest and Cunninghamia lanceolata plantation, respectively. The effects of forest types on soil mineral N pool were only significant on soil NO₃^--N, and the concentration of NO₃^--N in Castanopsis kawakamii was significantly lower than in the other two forests. The NO₃^--N and mineral N pool varied seasonally in all forests, and were higher in dormant season (October to February) than in growing season (March to September). Soil nitrification rate was very low in the whole year in all three forests and soil net ammonification was the major process of soil net mineralization. Tree species significantly affected soil net ammonification rate, and the value under Chinese fir was significantly lower than the other two fore-sts. The seasonal patterns of the soil net ammonification rate were not similar in all the three forests, but with the lowest value occurring in November and February in the following year. Analysis using variance of repeated measures indicated that soil mineral N concentrations and soil N mineralization rates were significantly affected by forest type and season, and correlation analysis showed that soil mineral N and soil N mineralization rate were significantly affected by water moisture and temperature, and the effects of litter on soil N mineralization rate were mainly through quality control, ra-ther than the quantity control.

Key words: forest type, soil available N, litterfall, Chinese fir, soil nitrogen transformation rate

XIAO Hao-yan, LIU Bao, YU Zai-peng, WAN Xiao-hua, SANG Chang-peng, ZHOU Fu-wei, HUANG Zhi-qun. Seasonal dynamics of soil mineral nitrogen pools and nitrogen mineralization rate in different forests in subtropical China[J]. Chinese Journal of Applied Ecology, 2017, 28(3): 730-738.

References

[1] Chapin FS, Matson PAI, Mooney HA. Principles of Terrestrial Ecosystem Eology. New York, USA: Sprin-ger, 2002
[2] Tateno R, Takeda H. Nitrogen uptake and nitrogen use efficiency above and below ground along a topographic gradient of soil nitrogen availability. Oecologia, 2010, 163: 793-804
[3] Rabalais NN. Nitrogen in aquatic ecosystems. Ambio, 2002, 31: 102-112
[4] Groffmann PM, Zak DR, Christensen S, et al. Early spring nitrogen dynamics in a temperate forest landscape. Ecology, 1993, 74: 1579-1585
[5] Thébault A, Clément JC, Ibanez S, et al. Nitrogen limitation and microbial diversity at the treeline. Oikos, 2014, 123: 729-740
[6] Pérez CA, Hedin LO, Armesto JJ. Original articles: Nitrogen mineralization in two unpolluted old-growth fore-sts of contrasting biodiversity and dynamics. Ecosystems, 1998, 1: 361-373
[7] Cheng Y, Wang J, Mary B, et al. Soil pH has contrasting effects on gross and net nitrogen mineralizations in adjacent forest and grassland soils in central Alberta, Canada. Soil Biology & Biochemistry, 2013, 57: 848-857
[8] Ros GH, Hanegraaf MC, Hoffland E, et al. Predicting soil N mineralization: Relevance of organic matter fractions and soil properties. Soil Biology & Biochemistry, 2011, 43: 1714-1722
[9] Hishi T, Urakawa R, Tashiro N, et al. Seasonality of factors controlling N mineralization rates among positions and aspects in cool-temperate deciduous natural forests and larch plantations. Biology and Fertility of Soils, 2014, 50: 343-356
[10] Templer PH, Lovett GM, Weathers KC, et al. Influence of tree species on forest nitrogen retention in the Catskill Mountains, New York, USA. Ecosystems, 2005, 8: 1-16
[11] Isobe K, Koba K, Otsuka S, et al. Nitrification and nitrifying microbial communities in forest soils. Journal of Ethnopharmacology, 1987, 21: 351-362
[12] Huang ZQ, Wan XH, He ZM, et al. Soil microbial biomass, community composition and soil nitrogen cycling in relation to tree species in subtropical China. Soil Bio-logy & Biochemistry, 2013, 62: 68-75
[13] Lovett GM, Weathers KC, Arthur MA, et al. Nitrogen cycling in a northern hardwood forest: Do species matter? Biogeochemistry, 2004, 67: 289-308
[14] Chen Y-P (陈印平), Pan K-W (潘开文), Wu N (吴宁), et al. Effect of litter quality and decomposition on N mineralization in soil ofCastanopsis platyacantha-Schima sinensis forest. Chinese Journal of Applied and Environmental Biology (应用与环境生物学报), 2005, 11(2): 146-151 (in Chinese)
[15] Scott NA, Dan B. Foliage litter quality and annual net N mineralization: Comparison across North American fore-st sites. Oecologia, 1997, 111: 151-159
[16] Cookson WR, Cornforth IS, Rowarth JS. Winter soil temperature (2-15 ℃) effects on nitrogen transformations in clover green manure amended or unamended soils: A laboratory and field study. Soil Biology & Biochemistry, 2002, 34: 1401-1415
[17] Dalias P, Anderson JM, Bottner P, et al. Temperature responses of net nitrogen mineralization and nitrification in conifer forest soils incubated under standard laboratory conditions. Soil Biology & Biochemistry, 2002, 34: 691-701
[18] Wang C, Han X, Xing X. Effects of grazing exclusion on soil net nitrogen mineralization and nitrogen availability in a temperate steppe in northern China. Journal of Arid Environments, 2010, 74: 1287-1293
[19] Shibata H, Urakawa R, Toda H, et al. Changes in nitrogen transformation in forest soil representing the climate gradient of the Japanese archipelago. Journal of Forest Research, 2011, 16: 374-385
[20] Lin S, Yu Z. Secondary forest floristic composition, structure, and spatial pattern in subtropical China. Journal of Forest Research, 2011, 18: 111-120
[21] Joergensen RG. The fumigation-extraction method to estimate soil microbial biomass: Calibration of the k_EC value. Soil Biology and Biochemistry, 1996, 28: 25-31
[22] Joergensen RG, Mueller T. The fumigation-extraction method to estimate soil microbial biomass: Calibration of the k_EN value. Soil Biology & Biochemistry, 1996, 28: 33-37
[23] Su P (苏波), Li G-C (李贵才). Factors affecting soil N availability in forest ecosystems: A literature review. Chinese Journal of Ecology (生态学杂志), 2002, 21(2): 40-46 (in Chinese)
[24] Fang Y-T (方运霆), Mo J-M (莫江明), Gundersen P, et al. Nitrogen transformations in forest soils and its responses to atmospheric nitrogen deposition: A review. Acta Ecologica Sinica (生态学报), 2004, 24(7): 1523-1531 (in Chinese)
[25] Tan B, Wu FZ, Yang WQ, et al. The dynamics pattern of soil carbon and nutrients as soil thawing proceeded in the alpine/subalpine forest. Acta Agriculturae Scandinavica, Section B: Soil & Plant Science, 2011, 61: 670-679
[26] Li M (李铭), Zhu L-C (朱利川), Zhang Q-F (张全发), et al. Impacts of different land use types on soil nitrogen mineralization in Danjiangkou Reservoir Area, China. Chinese Journal of Plant Ecology (植物生态学报), 2012, 36(6): 530-538 (in Chinese)
[27] Li J-Z (李检舟), Sha L-Q (沙丽清), Wang J (王君), et al. Seasonal variation of soil nitrogen mineralization in a mountane moist evergreen broad-leaved forest in Ailao Mountains, SW China. Journal of Mountain Science (山地学报), 2006, 24(2): 186-192 (in Chinese)
[28] Zhang J. Heterotrophic nitrification is the predominant NO production mechanism in coniferous but not broad-leaf acid forest soil in subtropical China. Biology and Fertility of Soils, 2011, 47: 533-542
[29] Davidson EA, Hart SC, Firestone MK. Internal cycling of nitrate in soils of a mature coniferous forest. Ecology, 1992, 73: 1148-1156
[30] Nadelhoffer KJ, Melillo JM. Fine roots, net primary production, and soil nitrogen availability: A new hypothesis. Ecology, 1985, 66: 1377-1390
[31] Plymale AE, Boerner REJ, Logan TJ. Relative nitrogen mineralization and nitrification in soils of two contrasting hardwood forests: Effects of site microclimate and initial soil chemistry. Forest Ecology and Management, 1987, 21: 21-36
[32] Zhou C-P (周才平), Ouyang H (欧阳华), Liu J-F (刘金福). Temperature and moisture effects on soil nitrogen mineralization in deciduous broad-leaved forest. Chinese Journal of Plant Ecology (植物生态学报), 2001, 25(2): 204-209 (in Chinese)
[33] Guntiñas ME, Leirós MC, Trasar-Cepeda C, et al. Effects of moisture and temperature on net soil nitrogen mineralization: A laboratory study. European Journal of Soil Biology, 2012, 48: 73-80
[34] Paul KI, Polglase PJ, O’Connell AM, et al. Defining the relation between soil water content and net nitrogen mineralization. European Journal of Soil Science, 2003, 54: 39-48
[35] Bernhard-Reversat F. Soil nitrogen mineralization under a Eucalyptus plantation and a natural Acacia forest in Senegal. Forest Ecology and Management, 1988, 23: 233-244
[36] Stanford G, Epstein E. Nitrogen mineralization-water relations in soils. Soil Science Society of America Journal, 1974, 38: 289-299
[37] Wang C, Wan S, Xing X, et al. Temperature and soil moisture interactively affected soil net N mineralization in temperate grassland in Northern China. Soil Biology & Biochemistry, 2006, 38: 1101-1110
[38] Yan ER, Wang XH, Huang JJ, et al. Decline of soil nitrogen mineralization and nitrification during forest conversion of evergreen broad-leaved forest to plantations in the subtropical area of Eastern China. Biogeochemistry, 2008, 89: 239-251
[39] Ross DS, Lawrence GB, Fredriksen G. Mineralization and nitrification patterns at eight northeastern USA fore-sted research sites. Forest Ecology and Management, 2004, 188: 317-335
[40] Kalbitz K, Schwesig D, Schmerwitz J, et al. Changes in properties of soil-derived dissolved organic matter induced by biodegradation. Soil Biology & Biochemistry, 2003, 35: 1129-1142
[41] Kaiser K, Guggenberger G, Haumaier L, et al. The composition of dissolved organic matter in forest soil solutions: Changes induced by seasons and passage through the mineral soil. Organic Geochemistry, 2002, 33: 307-318
[42] Smolander A, Kanerva S, Adamczyk B, et al. Nitrogen transformations in boreal forest soils-does composition of plant secondary compounds give any explanations? Earth and Planetary Science Letters, 2013, 304: 259-270
[43] Sánchez LF, García J. Nitrogen mineralization in soils under grasses and under trees in a protected Venezuelan savanna. Acta Oecologica, 1997, 18: 27-37