沙区生物土壤结皮演替对表层土壤养分和微生物群落组成的影响

doi:10.12118/j.issn.1000-6060.2024.322

摘要/Abstract

摘要：

生物土壤结皮是旱地生态系统的重要组成部分，在土壤表面生物和非生物因子的相互作用中发挥着重要作用。研究了腾格里沙漠南缘不同类型生物土壤结皮及其下0~2 cm和2~5 cm层土壤理化性质、微生物群落组成和酶活性，分析了土壤微生物群落组成和酶活性随结皮演替的变化特征及其与土壤理化性质的关系。结果表明：（1）随着结皮向着以藓类为优势的群落演替，结皮层及下层土壤有机碳、全氮、全磷、电导率（EC）及黏粉粒含量均呈显著增大趋势，但随着土层深度的增加而显著减小；pH、容重及砂粒含量则呈相反趋势。（2）结皮层总PLFAs、细菌和真菌PLFAs均表现为藓结皮>地衣结皮>藻结皮，藓结皮与藻结皮相比分别增加了24%、15%和39%；与藻结皮相比，藓结皮真菌和细菌PLFAs的比值（F:B）增加了20%。结皮下0~2 cm和2~5 cm土层微生物群落组成表现出相似的规律，但各参数均随土层深度的增加而显著减小。（3）结皮层及其下0~2 cm和2~5 cm层土壤蔗糖酶、过氧化氢酶、纤维素酶、淀粉酶、多酚氧化酶、过氧化物酶、脲酶和碱性磷酸酶活性均随结皮演替而显著升高，但其活性均随土层深度的增加而显著减小。（4）土壤微生物群落组成和酶活性与土壤有机碳、全氮、全磷、EC和黏粉粒含量呈显著正相关，而与pH、容重及砂粒含量呈显著负相关。结构方程模型分析表明结皮演替引发的土壤化学属性的变化是微生物群落和酶活性的关键驱动因子。

关键词: 微生物群落, 酶活性, 生物土壤结皮, 演替, 沙区

Abstract:

Biological soil crusts (BSCs), a critical component of dryland ecosystems, mediate interactions between biotic and abiotic factors on the soil surface. This study examines the soil physicochemical properties, microbial community composition, and enzyme activities of different types of BSCs—algae-dominated (AC), lichen-dominated (LC), and moss-dominated (MC)—along with the underlying soil layers (0-2 cm and 2-5 cm) at the southern edge of the Tengger Desert, Inner Mongolia, China. We analyzed variations in microbial community composition and enzyme activities during BSCs succession and explored the relationship between these dynamics and soil physicochemical properties. Results revealed that the contents of soil organic carbon (SOC), nitrogen (N), phosphorus (P), silt, clay, and electrical conductivity (EC) in both crust and underlying soils increased significantly as BSCs progressed toward moss dominance, while these variables decreased with greater soil depth. Conversely, pH, bulk density, and sand content exhibited opposing trends. The total phospholipid fatty acids (PLFAs), as well as bacterial and fungal PLFAs, were highest in MC and lowest in AC, with MC exhibiting 24%, 15%, and 39% higher values than AC, respectively. Compared to AC, the fungal-to-bacterial PLFAs ratio (F:B) in MC increased by 20%. The microbial community composition in the 0-2 cm and 2-5 cm soil layers followed similar patterns, though all parameters significantly declined with depth. Enzyme activities—sucrase, catalase, cellulase, amylase, polyphenol oxidase, peroxidase, urease, and alkaline phosphatase—showed an upward trend with BSCs succession, but decreased with soil depth. Further analysis revealed that microbial community composition and enzyme activities were significantly positively correlated with SOC, N, P, EC, and clay content, but negatively correlated with pH, bulk density, and sand content. Structural equation modeling suggested that changes in soil chemical properties driven by BSCs succession were the key determinants of microbial community structure and enzyme activities.

Key words: microbial community, enzyme activity, biological soil crusts, succession, desert region

贺郝钰, 刘蔚, 常宗强, 侯春梅, 孙力炜, 迟秀丽. 沙区生物土壤结皮演替对表层土壤养分和微生物群落组成的影响[J]. 干旱区地理, 2024, 47(10): 1724-1734.

HE Haoyu, LIU Wei, CHANG Zongqiang, HOU Chunmei, SUN Liwei, CHI Xiuli. Effects of biological soil crust succession on soil nutrients, microbial community composition in desert regions[J]. Arid Land Geography, 2024, 47(10): 1724-1734.

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参考文献 50

[1]	Belnap J, Büdel B, Lange O L. Biological soil crusts: Characteristics and distribution[C]// Biological Soil Crusts: Structure, Function, and Management. Heidelberg: Springer, 2001: 3-30.
[2]	Xie T, Shi W L, Yang H T, et al. Variations in organic carbon mineralization of the biological soil crusts following revegetation in the Tengger Desert, north China[J]. Catena, 2023, 222: 106860, doi: 10.1016/j.catena.2022.106860.
[3]	Li X R, Jia R L, Zhang Z S, et al. Hydrological response of biological soil crusts to global warming: A ten-year simulative study[J]. Global Change Biology, 2018, 24(10): 4960-4971.
[4]	王新平, 肖洪浪, 张景光, 等. 荒漠地区生物土壤结皮的水文物理特征分析[J]. 水科学进展, 2006, 17(5): 592-598.
	[Wang Xinping, Xiao Honglang, Zhang Jingguang, et al. Hydrophysical characteristics of biological soil crust in an arid desert area[J]. Advances in Water Science, 2006, 17(5): 592-598.]
[5]	苏延桂, 李新荣, 陈应武, 等. 生物土壤结皮对荒漠土壤种子库和种子萌发的影响[J]. 生态学报, 2007, 27(3): 938-946.
	[Su Yangui, Li Xinrong, Chen Yingwu, et al. Effects of biological soil crusts on soil seed bank and seed germination of desert plants in north China[J]. Acta Ecologica Sinica, 2007, 27(3): 938-946.]
[6]	Rodriguez-caballero E, Belnap J, Büdel B, et al. Dryland photoautotrophic soil surface communities endangered byglobal change[J]. Nature Geoscience, 2018, 11: 185-189.
[7]	Li X R, Zhang P, Su Y G, et al. Carbon fixation by biological soil crusts following revegetation of sand dunes in arid desert regions of China: A four-year field study[J]. Catena, 2012, 97: 119-126.
[8]	Yair A, Verrecchia E. The role of the mineral component in surface stabilization processes of a disturbed desert sandy surface[J]. Land Degradation & Development, 2002, 13(4): 295-306.
[9]	Pietrasiak N, Regus J U, Johansen J R, et al. Biological soil crust community types differ in key ecological functions[J]. Soil Biology and Biochemistry, 2013, 65: 168-171.
[10]	Housman D C, Yeager C M, Darby B J, et al. Heterogeneity of soil nutrients and subsurface biota in a dryland ecosystem[J]. Soil Biology and Biochemistry, 2007, 39(8): 2138-2149.
[11]	He M Z, Hu R, Jia R L. Biological soil crusts enhance the recovery of nutrient levels of surface dune soil in arid desert regions[J]. Ecological Indicators, 2019, 106: 105497, doi: 10.1016/j.ecolind.2019.105497.
[12]	Liu Y M, Yang H Y, Li X R, et al. Effects of biological soil crusts on soil enzyme activities in revegetated areas of the Tengger Desert, China[J]. Applied Soil Ecology, 2014, 80: 6-14.
[13]	Zhang B C, Zhang Y Q, Li X Z, et al. Successional changes of fungal communities along the biocrust development stages[J]. Biology and Fertility of Soils, 2018, 54(2): 285-294.
[14]	Zhao K, Zhang B C, Li J N, et al. The autotrophic community across developmental stages of biocrusts in the Gurbantunggut Desert[J]. Geoderma, 2021, 388: 114927, doi: 10.1016/j.geoderma.2021.114927.
[15]	Xu L, Zhang B C, Wang E T, et al. Soil total organic carbon/total nitrogen ratio as a key driver deterministically shapes diazotrophic community assemblages during the succession of biological soil crusts[J]. Soil Ecology Letters, 2021, 3(4): 328-341. doi: 10.1007/s42832-020-0075-x
[16]	Liu Y B, Zhao L N, Wang Z R, et al. Changes in functional gene structure and metabolic potential of the microbial community in biological soil crusts along a revegetation chronosequence in the Tengger Desert[J]. Soil Biology and Biochemistry, 2018, 126: 40-48.
[17]	Liu Y B, Wang Y S, Wang Z R, et al. Characteristics of iron cycle and its driving mechanism during the development of biological soil crusts associated with desert revegetation[J]. Soil Biology and Biochemistry, 2022, 164: 108487, doi: 10.1016/j.soilbio.2021.108487.
[18]	Xu L, Zhu B J, Li C N, et al. Increasing relative abundance of non-cyanobacterial photosynthetic organisms drives ecosystem multifunctionality during the succession of biological soil crusts[J]. Geoderma, 2021, 395: 115052, doi: 10.1016/j.geoderma.2021.115052.
[19]	Miralles I, Domingo F, García-Campos E, et al. Biological and microbial activity in biological soil crusts from the Tabernas Desert, a sub-arid zone in SE Spain[J]. Soil Biology and Biochemistry, 2012, 55: 113-121.
[20]	王融融, 樊瑾, 丛士翔, 等. 毛乌素沙地火电厂周边不同类型生物结皮酶活性及其影响因素[J]. 中国沙漠, 2023, 43(4): 209-219. doi: 10.7522/j.issn.1000-694X.2023.00011
	[Wang Rongrong, Fan Jin, Cong Shixiang, et al. Enzyme activity characteristics and their influencing factors of different biocrusts around thermal plant in Mu Us Sandy Land[J]. Journal of Desert Research, 2023, 43(4): 209-219.] doi: 10.7522/j.issn.1000-694X.2023.00011
[21]	刘玉冰, 王增如, 高天鹏. 温带荒漠生物土壤结皮微生物群落结构与功能演替研究综述[J]. 微生物学通报, 2020, 47(9): 2974-2983.
	[Liu Yubing, Wang Zengru, Gao Tianpeng. Succession of microbial community structure and their functions of biological soil crusts in temperate desert: A review[J]. Microbiology China, 2020, 47(9): 2974-2983.]
[22]	Hu R, Wang X P, Xu J S, et al. The mechanism of soil nitrogen transformation under different biocrusts to warming and reduced precipitation: From microbial functional genes to enzyme activity[J]. The Science of the Total Environment, 2020, 722: 137849, doi: 10.1016/j.scitotenv.2020.137849.
[23]	Garcia-pichel F, Pringault O. Cyanobacteria track water in desert soils[J]. Nature, 2001, 413: 380-381.
[24]	Grote E E, Belnap J, Housman D C, et al. Carbon exchange in biological soil crust communities under differential temperatures and soil water contents: Implications for global change[J]. Global Change Biology, 2010, 16(10): 2763-2774.
[25]	马全林. 腾格里沙漠南缘土壤-植被系统恢复及其驱动机制[D]. 兰州: 中国科学院寒区旱区环境与工程研究所, 2009.
	[Ma Quanlin. Restoration of soil-vegetation system and its driving mechanism in the southern margin of Tengger Desert[D]. Lanzhou: Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, 2009.]
[26]	都军, 李宜轩, 杨晓霞, 等. 腾格里沙漠东南缘生物土壤结皮对土壤理化性质的影响[J]. 中国沙漠, 2018, 38(1): 111-116. doi: 10.7522/j.issn.1000-694X.2017.00073
	[Du Jun, Li Yixuan, Yang Xiaoxia, et al. Effects of biological soil crusts types on soil physicochemical properties in the southeast fringe of the Tengger Desert[J]. Journal of Desert Research, 2018, 38(1): 111-116.] doi: 10.7522/j.issn.1000-694X.2017.00073
[27]	Frostegard, Baath E, Tunlio A. Shifts in the structure of soil microbial communities in limed forests as revealed by phospholipid fatty acid analysis[J]. Soil Biology and Biochemistry, 1993, 25(6): 723-730.
[28]	关松荫. 土壤酶及其研究法[M]. 北京: 农业出版社, 1986.
	[Guan Songyin. Soil enzyme and its research method[M]. Beijing: Agriculture Press, 1986.]
[29]	Chamizo S, Cantón Y, Miralles I, et al. Biological soil crust development affects physicochemical characteristics of soil surface in semiarid ecosystems[J]. Soil Biology and Biochemistry, 2012, 49: 96-105.
[30]	Li X R, Xiao H L, He M Z, et al. Sand barriers of straw checkerboards for habitat restoration in extremely arid desert regions[J]. Ecological Engineering, 2006, 28(2): 149-157.
[31]	Miralles I, ladrón de Guevara M, Chamizo S, et al. Soil CO₂ exchange controlled by the interaction of biocrust successional stage and environmental variables in two semiarid ecosystems[J]. Soil Biology and Biochemistry, 2018, 124: 11-23.
[32]	Mager D M. Carbohydrates in cyanobacterial soil crusts as a source of carbon in the southwest Kalahari, Botswana[J]. Soil Biology and Biochemistry, 2010, 42(2): 313-318.
[33]	Chamizo S, Cantón Y, Domingo F, et al. Evaporative losses from soils covered by physical and different types of biological soil crusts[J]. Hydrological Processes, 2013, 27(3): 324-332.
[34]	Xie Y C, Wen X M, Tu Y L, et al. Mechanisms of artificial biological soil crusts development for anti-desertification engineering on the Qinghai-Tibetan Plateau[J]. Environmental Technology & Innovation, 2024, 33: 103542, doi: 10.1016/j.eti.2024.103542.
[35]	Housman D C, Powers H H, Collins A D, et al. Carbon and nitrogen fixation differ between successional stages of biological soil crusts in the Colorado Plateau and Chihuahuan Desert[J]. Journal of Arid Environments, 2006, 66(4): 620-634.
[36]	Jayne B, Gardner John S. Soil microstructure in soils of the Colorado Plateau: The role of the cyanobacterium microcoleus vaginatus[J]. The Great Basin Naturalist, 1993, 53(1): 40-47.
[37]	Zhang L X, Zhou B, Song B, et al. Significant carbon isotopic fractionation during early formation of biological soil crusts with indications for dryland carbon cycling[J]. iScience, 2024, 27(3): 109114, doi: 10.1016/j.isci.2024.109114.
[38]	Maier S, Tamm A, Wu D M, et al. Photoautotrophic organisms control microbial abundance, diversity, and physiology in different types of biological soil crusts[J]. The ISME Journal, 2018, 12: 1032-1046.
[39]	焦冰洁, 张丙昌, 赵康, 等. 生物结皮演替对黄土高原水蚀风蚀交错区土壤氮素转化及微生物活性的促进效应[J]. 中国沙漠, 2023, 43(4): 191-199. doi: 10.7522/j.issn.1000-694X.2022.00139
	[Jiao Bingjie, Zhang Bingchang, Zhao Kang, et al. Promoting effect of biological soil crusts succession on soil nitrogen transformation and microbial activity in water-wind erosion crisscross region of Loess Plateau[J]. Journal of Desert Research, 2023, 43(4): 191-199.] doi: 10.7522/j.issn.1000-694X.2022.00139
[40]	Chamizo S, Rodríguez-Caballero E, Sánchez-Cañete E P, et al. Temporal dynamics of dryland soil CO₂ efflux using high-frequency measurements: Patterns and dominant drivers among biocrust types, vegetation and bare soil[J]. Geoderma, 2022, 405: 115404, doi: 10.1016/j.geoderma.2021.115404.
[41]	Pointing S B, Belnap J. Microbial colonization and controls in dryland systems[J]. Nature Reviews Microbiology, 2012, 10: 551-562. doi: 10.1038/nrmicro2831 pmid: 22772903
[42]	Cleveland C C, Nemergut D R, Schmidt S K, et al. Increases in soil respiration following labile carbon additions linked to rapid shifts in soil microbial community composition[J]. Biogeochemistry, 2007, 82(3): 229-240.
[43]	Iwai C B, Oo A N, Topark-Ngarm B. Soil property and microbial activity in natural salt affected soils in an alternating wet-dry tropical climate[J]. Geoderma, 2012, 189/190: 144-152.
[44]	Rousk J, Demoling L A, Bahr A, et al. Examining the fungal and bacterial niche overlap using selective inhibitors in soil[J]. FEMS Microbiology Ecology, 2008, 63(3): 350-358. doi: 10.1111/j.1574-6941.2008.00440.x pmid: 18205814
[45]	Wu H W, Cui H L, Fu C X, et al. Unveiling the crucial role of soil microorganisms in carbon cycling: A review[J]. The Science of the Total Environment, 2024, 909: 168627, doi: 10.1016/j.scitotenv.2023.168627.
[46]	杨娥女, 王宝荣, 姚宏佳, 等. 黄土高原生物土壤结皮发育过程中颗粒态和矿物结合态有机碳变化特征[J]. 水土保持研究, 2023, 30(1): 25-33, 40.
	[Yang Enü, Wang Baorong, Yao Hongjia, et al. Dynamics of particulate and mineral-associated organic carbon during the development of biological soil crusts in the Loess Plateau[J]. Research of Soil and Water Conservation, 2023, 30(1): 25-33, 40.]
[47]	张雪, 张春平, 杨晓霞, 等. 草地和荒漠生态系统生物土壤结皮对土壤养分及酶活性的影响[J]. 草地学报, 2023, 31(3): 632-640. doi: 10.11733/j.issn.1007-0435.2023.03.002
	[Zhang Xue, Zhang Chunping, Yang Xiaoxia, et al. Effects of biological soil crusts on soil nutrient and enzyme activities in grassland and desert ecosystems[J]. Acta Agrestia Sinica, 2023, 31(3): 632-640.] doi: 10.11733/j.issn.1007-0435.2023.03.002
[48]	武杰, 张丙昌, 陈静, 等. 黄土高原水蚀风蚀交错区不同生物结皮类型对土壤有机碳及其转化的影响[J]. 水土保持学报, 2024, 38(4): 38-44.
	[Wu Jie, Zhang Bingchang, Chen Jing, et al. Effects of different biocrust types on soil organic carbon and its transformation in the water wind erosion crisscross region of the Loess Plateau[J]. Journal of Soil and Water Conservation, 2024, 38(4): 38-44.]
[49]	Miralles I, Domingo F, Cantón Y, et al. Hydrolase enzyme activities in a successional gradient of biological soil crusts in arid and semi-arid zones[J]. Soil Biology and Biochemistry, 2012, 53: 124-132.
[50]	Dilly O, Munch J C, Pfeiffer E M. Enzyme activities and litter decomposition in agricultural soils in northern, central, and southern Germany[J]. Journal of Plant Nutrition and Soil Science, 2007, 170(2): 197-204.

类型	厚度/cm	盖度/%	隐花植物优势种	叶绿素a+b/μg·cm^-2
藻结皮	1.03±0.02	19.13±1.68	具鞘微鞘藻（Microcoleus vaginatus）、隐头舟形藻（Navicula cryptocephala）、爪哇伪枝藻（Scytonema javanicum）	2.36±0.18
地衣结皮	1.17±0.04	15.07±2.47	石果衣（Endocarpon pusillum）、糙聚盘衣（Glypholecia scabra）	3.17±0.27
藓结皮	1.49±0.09	29.34±4.03	真藓（Bryum argenteum）、土生对齿藓（Didymodon vinealis）、齿肋赤藓（Syntrichia caninervis）	4.03±0.33

土层	结皮类型	黏粒/%	粉粒/%	砂粒/%	容重/g·cm^-3	有机碳/g·kg^-1
结皮层	藻结皮	11.66±1.08Aa	24.68±1.58Aa	63.66±1.69Aa	1.16±0.03Aa	17.99±0.57Aa
	地衣结皮	11.04±1.49Aa	24.42±1.67Aa	64.54±3.15Aa	1.11±0.03Aa	21.20±2.12Ba
	藓结皮	15.14±0.73Ba	27.13±1.02Ba	57.73±0.88Ba	1.04±0.04Ba	24.99±1.59Ca
结皮下0~2 cm	藻结皮	4.49±0.37Ab	9.51±0.94Ab	86.01±1.30Ab	1.32±0.04Ab	3.84±0.15Ab
	地衣结皮	4.70±0.31Ab	10.10±1.04Ab	85.20±1.34Ab	1.30±0.04Ab	4.42±0.34Bb
	藓结皮	7.49±0.63Bb	21.85±0.61Bb	70.66±1.01Bb	1.20±0.02Bb	4.64±0.15Bb
结皮下2~5 cm	藻结皮	1.79±0.21Ac	4.57±0.23Ac	93.64±0.39Ac	1.46±0.01Ac	1.63±0.13Ac
	地衣结皮	2.07±0.08Ac	7.01±0.29Bc	90.92±0.29Bc	1.43±0.01Bc	2.12±0.03Bc
	藓结皮	2.77±1.41Bc	10.98±1.39Cc	86.25±1.41Cc	1.32±0.03Cc	2.80±0.18Cc
土层	结皮类型	全氮/g·kg^-1	全磷/g·kg^-1	EC/μS·cm^-1	pH
结皮层	藻结皮	1.34±0.07Aa	0.55±0.04Aa	174.47±4.74Aa	8.01±0.03Aa
	地衣结皮	1.49±0.05Aa	0.62±0.02Aa	187.73±4.06Aa	8.02±0.06Aa
	藓结皮	1.74±0.10Ba	0.78±0.03Ba	247.38±13.67Aa	7.71±0.05Ba
结皮下0~2 cm	藻结皮	0.34±0.02Ab	0.50±0.02Aa	79.58±3.28Ab	8.31±0.04Ab
	地衣结皮	0.31±0.04Ab	0.54±0.02Ab	82.78±2.29Ab	8.14±0.04Bb
	藓结皮	0.61±0.13Bb	0.64±0.02Bb	114.94±13.72Ab	8.08±0.05Bb
结皮下2~5 cm	藻结皮	0.24±0.05Ac	0.40±0.02Ab	71.99±1.31Ac	8.53±0.04Ac
	地衣结皮	0.29±0.01Ac	0.43±0.01Ac	83.21±4.01Bc	8.40±0.06Bc
	藓结皮	0.37±0.03Bc	0.53±0.03Bc	103.43±9.18Ab	8.23±0.05Cc

土壤理化性质	结皮类型		土层		结皮类型×土层
土壤理化性质	F	P	F	P	F	P
黏粒/%	12.151	<0.001	163.003	<0.001	1.599	0.218
粉粒/%	37.192	<0.001	207.552	<0.001	7.099	0.001
砂粒/%	37.142	<0.001	275.449	<0.001	4.132	0.514
容重/g·cm^-3	24.114	<0.001	46.844	<0.001	0.766	0.561
有机碳/g·kg^-1	7.981	0.003	396.440	<0.001	3.640	0.204
全氮/g·kg^-1	13.825	<0.001	314.947	<0.001	1.536	0.234
全磷/g·kg^-1	38.701	<0.001	51.625	<0.001	1.448	0.259
EC/μS·cm^-1	30.847	<0.001	219.799	<0.001	2.710	0.063
pH	25.348	<0.001	73.662	<0.001	2.010	0.136

参数	砂粒	粉粒	黏粒	容重	有机碳	全氮	全磷	EC	pH
细菌PLFAs	-0.922^**	0.905^**	0.910^**	-0.765^**	0.924^**	0.940^**	0.746^**	0.933^**	-0.851^**
真菌PLFAs	-0.913^**	0.897^**	0.900^**	-0.838^**	0.898^**	0.915^**	0.843^**	0.931^**	-0.907^**
F:B	-0.739^**	0.744^**	0.696^**	-0.838^**	0.628^**	0.660^**	0.892^**	0.707^**	-0.868^**
总PLFAs	-0.913^**	0.901^**	0.891^**	-0.810^**	0.889^**	0.912^**	0.797^**	0.918^**	-0.882^**
蔗糖酶	-0.917^**	0.879^**	0.942^**	-0.796^**	0.961^**	0.960^**	0.764^**	0.959^**	-0.840^**
过氧化氢酶	-0.938^**	0.908^**	0.948^**	-0.759^**	0.962^**	0.961^**	0.729^**	0.918^**	-0.835^**
纤维素酶	-0.882^**	0.840^**	0.917^**	-0.699^**	0.972^**	0.971^**	0.731^**	0.958^**	-0.796^**
淀粉酶	-0.910^**	0.870^**	0.939^**	-0.732^**	0.980^**	0.972^**	0.712^**	0.946^**	-0.812^**
多酚氧化酶	-0.626^**	0.635^**	0.579^**	-0.753^**	0.520^*	0.558^*	0.782^**	0.667^*	-0.714^**
过氧化物酶	-0.841^**	0.793^**	0.888^**	-0.792^**	0.947^**	0.930^**	0.792^**	0.952^**	-0.814^**
脲酶	-0.874^**	0.840^**	0.896^**	-0.765^**	0.930^**	0.935^**	0.764^**	0.948^**	-0.821^**
碱性磷酸酶	-0.868^**	0.840^**	0.879^**	-0.778^**	0.929^**	0.933^**	0.790^**	0.939^**	-0.807^**