Effects of grazing intensity and grazing exclusion on litter decomposition in the temperate steppe of Nei Mongol, China

doi:10.17521/cjpe.2016.00051

Abstract

Abstract:

Aims Grazing intensity and grazing exclusion affect ecosystem carbon cycling by changing the plant community and soil micro-environment in grassland ecosystems. The aims of this study were: 1) to determine the effects of grazing intensity and grazing exclusion on litter decomposition in the temperate grasslands of Nei Mongol; 2) to compare the difference between above-ground and below-ground litter decomposition; 3) to identify the effects of precipitation on litter production and decomposition. Methods We measured litter production, quality, decomposition rates and soil nutrient contents during the growing season in 2011 and 2012 in four plots, i.e. light grazing, heavy grazing, light grazing exclusion and heavy grazing exclusion. Quadrate surveys and litter bags were used to measure litter production and decomposition rates. All data were analyzed with ANOVA and Pearson’s correlation procedures in SPSS. Important findings Litter production and decomposition rates differed greatly among four plots. During the two years of our study, above-ground litter production and decomposition in heavy-grazing plots were faster than those in light-grazing plots. In the dry year, below-ground litter production and decomposition in light-grazing plots were faster than those in heavy-grazing plots, which is opposite to the findings in the wet year. Short-term grazing exclusion could promote litter production, and the exclusion of light-grazing could increase litter decomposition and nutrient cycling. In contrast, heavy-grazing exclusion decreased litter decomposition. Thus, grazing exclusion is beneficial to the restoration of the light-grazing grasslands, and more human management measures are needed during the restoration of heavy-grazing grasslands. Precipitation increased litter production and decomposition, and below-ground litter was more vulnerable to the inter-annual change of precipitation than above-ground litter. Compared to the light-grazing grasslands, heavy-grazing grasslands had higher sensitivity to precipitation. The above-ground litter decomposition was strongly positively correlated with the litter N content (R²= 0.489, p < 0.01) and strongly negatively correlated with the soil total N content (R² = 0.450, p < 0.01), but it was not significantly correlated with C:N and lignin:N. Below-ground litter decomposition was negatively correlated with the litter C (R² = 0.263, p < 0.01), C:N (R² = 0.349, p < 0.01) and cellulose content (R² = 0.460, p < 0.01). Our results will provide a theoretical basis for ecosystem restoration and the research of carbon cycling.

http://jtp.cnki.net/bilingual/detail/html/ZWSB201608002

Key words: grazing intensity, grazing exclusion, precipitation, litter decomposition, litter production, litter quality

Li-Li YANG, Ji-Rui GONG, Yi-Hui WANG, Min LIU, Qin-Pu LUO, Sha XU, Yan PAN, Zhan-Wei ZHAI. Effects of grazing intensity and grazing exclusion on litter decomposition in the temperate steppe of Nei Mongol, China[J]. Chin J Plant Ecol, 2016, 40(8): 748-759.

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URL: https://www.plant-ecology.com/EN/10.17521/cjpe.2016.00051

https://www.plant-ecology.com/EN/Y2016/V40/I8/748

Figures/Tables 8

Table 1 Basic information of the sampling plots (mean ± SE, n = 5)

样地基本信息 Basic information of the sampling plots	轻度放牧样地 Light grazing plot	重度放牧样地 Heavy grazing plot
平均高度 Average height (cm)	13.11 ± 1.46^b	19.85 ± 1.13^a
平均盖度 Average coverage (%)	57.36 ± 3.92^a	65.29 ± 2.55^a
地上生物量 Above-ground biomass (g·m^-2)	62.26 ± 0.89^b	108.76 ± 5.51^a
粪便数 Number of feces (No.·m^-2)	575.50 ± 2.04^b	1 230.00 ± 12.25^a

Table 2 The impact of sampling plots, year and their interactions on above- ground litter production, quality, decomposition and soil total C and N

	Y	P	Y × P
凋落物产量 Litter production	< 0.01	< 0.01	< 0.01
凋落物分解速率 Litter decomposition	< 0.01	< 0.01	< 0.01
凋落物C 含量 Litter C content	< 0.01	< 0.01	0.02
凋落物N含量 Litter N content	0.01	0.04	0.01
凋落物纤维素含量 Litter cellulose content	< 0.01	< 0.01	0.01
凋落物木质素含量 Litter lignin content	< 0.01	0.02	0.03
凋落物C:N Litter C:N	< 0.01	< 0.01	0.27
凋落物木质素:N Litter lignin:N	< 0.01	< 0.01	< 0.01
土壤全C Soil total C	0.01	< 0.01	< 0.01
土壤全N Soil total N	< 0.01	0.01	0.03

Table 3 The impact of sampling plots, year and their interactions on below-ground litter production, quality and decomposition rates

	Y	P	Y × P
凋落物产量 Litter production	< 0.01	< 0.01	< 0.01
凋落物分解速率 Litter decomposition	< 0.01	< 0.01	< 0.01
凋落物C含量 Litter C content	< 0.01	< 0.01	0.09
凋落物N含量 Litter N content	0.07	< 0.01	< 0.01
凋落物纤维素含量 Litter cellulose content	< 0.01	< 0.01	0.04
凋落物木质素含量 Litter lignin content	0.45	< 0.01	< 0.01
凋落物C:N Litter C:N	< 0.01	0.05	< 0.01
凋落物木质素:N Litter lignin:N	0.40	0.07	< 0.01

Fig. 1 Above-ground (A) and below-ground (B) litter production in the four treatment plots in 2011 and 2012 (mean ± SE). Capital letters indicate significant difference in litter production between different plots in 2011 at 0.05 levels, and lowercase letters indicate significant difference in litter production between different plots in 2012 at 0.05 levels. HG, heavy-grazing; HGE, heavy-grazing exclusion; LG, light-grazing; LGE, light-grazing exclusion .

Fig. 2 Above-ground litter C content (A), N content (B), C:N (C), cellulose content (D), lignin content (E) and lignin:N (F) in four plots in 2011 and 2012 (mean ± SE). Capital letters indicate significant difference in litter quality between different plots in 2011 at 0.05 levels, and lowercase letters indicate significant difference in litter quality between different plots in 2012 at 0.05 levels. HG, heavy-grazing; HGE, heavy-grazing exclusion; LG, light-grazing; LGE, light-grazing exclusion.

Fig. 3 Below-ground litter C content (A), N content (B), C:N (C), cellulose content (D), lignin content (E) and lignin:N (F) in four plots in 2011 and 2012 (mean ± SE). Different capital letters indicate significant difference in litter quality between different plots in 2011 at 0.05 levels, and different lowercase letters indicate significant difference in litter quality between different plots in 2012 at 0.05 levels. HG, heavy-grazing; HGE, heavy-grazing exclusion; LG, light-grazing; LGE, light-grazing exclusion.

Fig. 4 Aboveground (A) and belowground (B) litter decomposition rates (k) in four plots in 2011 and 2012 (mean ± SE). Different capital letters indicate significant difference in litter decomposition rate between different plots in 2011 at 0.05 levels, and different lowercase letters indicate significant difference in litter decomposition rate between different plots in 2012 at 0.05 levels. HG, heavy-grazing; HGE, heavy-grazing exclusion; LG, light-grazing; LGE, light-grazing exclusion.

Fig. 5 Soil total C (A) and total N content (B) in four plots in 2011 and 2012 (mean ± SE). Different capital letters indicate significant difference in soil nutrient content between different plots in 2011 at 0.05 levels, and different lowercase letters indicate significant difference in soil nutrient content between different plots in 2012 at 0.05 levels. HG, heavy-grazing; HGE, heavy-grazing exclusion; LG, light-grazing; LGE, light-grazing exclusion.

References 57

[1]	Aldezabal A, Moragues L, Odriozola I, Mijangos I (2015). Impact of grazing abandonment on plant and soil microbial communities in an Atlantic mountain grassland. Applied Soil Ecology, 96, 251-260.
[2]	An H, Li GQ (2014). Differential effects of grazing on plant functional traits in the desert grassland. Polish Journal of Ecology, 62, 239-251.
[3]	AOAC International (2000). AOAC official method 973.18 fiber (acid detergent) and lignin (H2SO4) in animal feed. In: Horwitz W ed. Official Methods of Analysis of AOAC International, 17th edn. Association of Official Analytical Chemists, Gaithersburg, USA.
[4]	Austin AT, Vitousek PM (2001). Precipitation, decomposition, and litter decomposability of Metrosideros polymorpha on Hawaii. Journal of Ecology, 88, 129-138.
[5]	Bai WM, Fang Y, Zhou M, Xie T, Li LH, Zhang WH (2015). Heavily intensified grazing reduces root production in an Inner Mongolia temperate steppe. Agriculture Ecosystems & Environment, 200, 143-150.
[6]	Bardgett RD, Manning P, Elly M, Franciska V (2013). Hierarchical responses of plant-soil interactions to climate change: Consequences for the global carbon cycle. Journal of Ecology, 101, 334-343.
[7]	Bontti EE, Decant JP, Munson SM, Gathany MA, Przeszlowska A, Haddix ML, Owens S, Burke IC, Parton WJ, Harmon ME (2009). Litter decomposition in grasslands of Central North America (US Great Plains). Global Change Biology, 15, 1356-1363.
[8]	Bremner JM (1960). Determination of nitrogen in soil by the Kjeldahl method. Journal of Agricultural Science, 55, 11-33.
[9]	Canadell JG, Mooney HA, Baldocchi DD, Berry JA, Ehleringer JR, Field CB, Gower ST, Hollinger DY, Hunt JE (2000). Carbon metabolism of the terrestrial biosphere: A multitechnique approach for improved understanding. Ecosystems, 3, 115-130.
[10]	Cingolani AM, Posse G, Collantes MB (2005). Plant functional traits, herbivore selectivity and response to sheep grazing in Patagonian steppe grasslands. Journal of Applied Ecology, 42(42), 50-59.
[11]	Dormaar JF, Willms WD (1990). Effect of grazing and cultiva- tion on some chemical properties of soils in the mixed prairie. Journal of Range Management, 43, 456-460.
[12]	Eldridge DJ, Westoby M, Holbrook KM (1992). Soil surface characteristics, microtopography and proximity to mature shrubs: Effects on survival of several cohorts of Atriplex vesicaria seedlings. Journal of Ecology, 78, 357-364.
[13]	Freschet GT, Cornwell WK, Wardle DA, Elumeeva TG, Liu W, Jackson BG, Onipchenko VG, Soudzilovskaia NA, Tao J, Cornelissen JH (2013). Linking litter decomposition of above- and below-ground organs to plant-soil feedbacks worldwide. Journal of Ecology, 101, 943-952.
[14]	Giese M, Gao YZ, Zhao Y, Pan QM, Lin S, Peth S, Brueck H (2009). Effects of grazing and rainfall variability on root and shoot decomposition in a semi-arid grassland. Applied Soil Ecology, 41, 8-18.
[15]	Gao YH, Chen H, Luo P, Wu N, Wang GX (2007). Effects of grazing intensity on decompositions of two dominant plant species litters in alpine meadow on the Northwester Sichuan. Ecological Science, 26(3), 193-198. (in Chinese with English abstract)[高永恒, 陈槐, 罗鹏, 吴宁, 王根绪 (2007). 放牧强度对川西北高山草甸两个优势物种凋落物分解的影响. 生态科学, 26(3), 193-198.]
[16]	Gong XY, Fanselow N, Dittert K, Taube F, Lin S (2015). Re- sponse of primary production and biomass allocation to nitrogen and water supplementation along a grazing intensity gradient in semiarid grassland. European Journal of Agronomy, 63, 27-35.
[17]	Greenwood KL, Hutchinson KJ (2003). Root characteristics of temperate pasture in New South Wales after grazing at three stocking rates for 30 years. Grass & Forage Science, 53, 120-128.
[18]	Hewins DB, Archer SR, Okin GS, Mcculley RL, Throop HL (2013). Soil-Litter mixing accelerates decomposition in a Chihuahuan Desert Grassland. Ecosystems, 16, 183-195.
[19]	Holland CA, Detling JK (1990). Plant response to herbivory and belowground nitrogen cycling. Ecology, 71, 1040-1049.
[20]	Hou FJ, Chang SH, Yu YW, Lin HL (2004). A review on trampling by grazed livestock. Acta Ecologica Sinica, 24, 784-789. (in Chinese with English abstract)[侯扶江, 常生华, 于应文, 林慧龙 (2004). 放牧家畜的践踏作用研究评述. 生态学报, 24, 784-789.]
[21]	Hu ZM, Li S, Guo Q, Niu SL, He NP, Li LH, Yu GR (2016). A synthesis of the effect of grazing exclusion on carbon dynamics in grasslands in China. Global Change Biology, 22, 1385-1393.
[22]	Koukoura Z, Mamolos AP, Kalburtji KL (2003). Decomposition of dominant plant species litter in a semi-arid grassland. Applied Soil Ecology, 23, 13-23.
[23]	Lindsay EA, Cunningham SA (2009). Livestock grazing exclusion and microhabitat variation affect invertebrates and litter decomposition rates in woodland remnants. Forest Ecology & Management, 258, 178-187.
[24]	Liu L, King JS, Booker FL, Giardina CP, Allen HL, Hu SJ (2009). Enhanced litter input rather than changes in litter chemistry drive soil carbon and nitrogen cycles under elevated CO2: A microcosm study. Global Change Biology, 15, 441-453.
[25]	Lu X, Yan Y, Sun J, Zhang XK, Chen YC, Wang XD, Cheng GW (2015). Carbon, nitrogen, and phosphorus storage in alpine grassland ecosystems of Tibet: Effects of grazing exclusion. Ecology & Evolution, 5, 4492-4504.
[26]	Mekuria W, Veldkamp E, Haile M, Nyssen J, Muys B, Gebrehiwot K (2007). Effectiveness of exclosures to restore degraded soils as a result of overgrazing in Tigray, Ethiopia. Journal of Arid Environments, 69, 270-284.
[27]	Mikan CJ, Schimel JP, Doyle AP (2002). Temperature controls of microbial respiration in arctic tundra soils above and below freezing. Soil Biology & Biochemistry, 34, 1785-1795.
[28]	Montané F, Romanyà J, Rovira P, Casals P (2010). Aboveground litter quality changes may drive soil organic carbon increase after shrub encroachment into mountain grasslands. Plant & Soil, 337, 151-165.
[29]	Nelson DW, Sommers LE (1982). Total carbon, organic carbon and organic matter. In: Page AL, Miller RH, Keeney DR eds. Methods of Soil Analysis. American Society of Agronomy, Madison, USA. 539-579.
[30]	Olson JS (1963). Energy storage and the balance of producers and decomposers in ecological systems. Ecology, 44, 322-331.
[31]	Pucheta E, Bonamici I, Cabido M, Díaz S (2004). Below- ground biomass and productivity of a grazed site and a neighbouring ungrazed exclosure in a grassland in central Argentina. Austral Ecology, 29, 201-208.
[32]	Qi YC, Dong YS, Geng YB, Yang XH, Geng HL (2003). The progress in the carbon cycle researches in grassland ecosystem in China. Progress in Geography, 22, 342-352. (in Chinese with English abstract)[齐玉春, 董云社, 耿元波,杨小红, 耿会立 (2003). 我国草地生态系统碳循环研究进展. 地理科学进展, 22, 342-352.]
[33]	Raich JW, Tufekciogul A (2000). Vegetation and soil respiration: Correlations and controls. Biogeochemistry, 48, 71-90.
[34]	Sanaullah M, Chabbi A, Girardin C, Durand JL, Poirier M, Rumpel C (2014). Effects of drought and elevated temperature on biochemical composition of forage plants and their impact on carbon storage in grassland soil. Plant & Soil, 374, 767-778.
[35]	Semmartin M, Ghersa CM (2006). Intraspecific changes in plant morphology, associated with grazing, and effects on litter quality, carbon and nutrient dynamics during decomposition. Austral Ecology, 31(1), 99-105.
[36]	Shariff AR, Grygiel CE (1994). Grazing intensity effects on litter decomposition and soil nitrogen mineralization. Journal of Range Management, 47, 444-449.
[37]	Shi FS, Chen H, Wu Y, Wu N (2010). Effects of livestock exclusion on vegetation and soil properties under two topographic habitats in an alpine meadow on the eastern Qinghai-Tibetan Plateau. Polish Journal of Ecology, 58, 125-133.
[38]	Smith SW, Woodin SJ, Pakeman RJ, David J, René VDW (2014). Root traits predict decomposition across a landscape-scale grazing experiment. New Phytologist, 203, 851-862.
[39]	Solly EF, Schöning I, Boch S, Kandeler E, Marhan S, Michalzik B, Müller J, Zscheischler J, Trumbore SE, Schrumpf M (2014). Factors controlling decomposition rates of fine root litter in temperate forests and grasslands. Plant & Soil, 382, 203-218.
[40]	Stark S, Männistö MK, Ganzert L, Tiirola M, Häggblom MM (2015). Grazing intensity in subarctic tundra affects the temperature adaptation of soil microbial communities. Soil Biology & Biochemistry, 84, 147-157.
[41]	Tateno R, Tokuchi N, Yamanaka N, Du S, Otsuki K, Shimamura T, Xue Z, Wang SQ, Hou QC (2007). Comparison of litterfall production and leaf litter decomposition between an exotic black locust plantation and an indigenous oak forest near Yan’an on the Loess Plateau, China. Forest Ecology & Management, 241(s1-3), 84-90.
[42]	Tessier M, Vivier JP, Ouin A, Gloaguen JC, Lefeuvre JC (2003). Vegetation dynamics and plant species interactions under grazed and ungrazed conditions in a western European salt marsh. Acta Oecologica, 24, 103-111.
[43]	van Soest PJ (1963). Use of detergents in analysis of fibrous feeds: A rapid method for the determination of fiber and lignin. Journal of the Association of Official Analytical Chemists, 46, 829-835.
[44]	van Soest PJ (1967). Development of a comprehensive system of feed analyses and its application to forages. Journal of Animal Science, 26, 119-128.
[45]	Wang L, Zhang Y, Xu DM, Zhang N (2013). Study on litter decomposition rates and N, P, K content of litter in different years of enclosure in desert steppe. Pratacultural Science, 30, 1508-1512. (in Chinese with English abstract)[王蕾, 张宇, 许冬梅, 张娜 (2013). 围封对草地凋落物分解速率和N、P、K含量的影响. 草业科学, 30, 1508-1512.]
[46]	Wang MJ, Han GD, Zhao ML, Chen HJ, Wang Z, Hao XL, Bo T (2007). The effects of different grazing intensity on soil organic carbon content in meadow steppe. Pratacultural Science, 10, 6-10. (in Chinese with English abstract)[王明君, 韩国栋, 赵萌莉, 陈海军, 王珍, 郝晓莉, 薄涛 (2007). 草甸草原不同放牧强度对土壤有机碳含量的影响. 草业科学, 10, 6-10.]
[47]	Wang YH, Gong JR, Liu M, Luo QP, Xu S, Pan Y, Zhai ZW (2015). Effects of land use and precipitation on above- and below-ground litter decomposition in a semi-arid temperate steppe in Inner Mongolia, China. Applied Soil Ecology, 96, 183-191.
[48]	Wardle DA, Bardgett RD, Klironomos JN, Heikki S, Wim H, Wall DH (2004). Ecological linkages between aboveground and belowground biota. Science, 304, 1629-1633.
[49]	Wen HY, Zhao HL, Fu H (2005). Effects of years for reclamation and enclosure years on soil properties of degraded sandy grassland. Scientia Agricultura Sinica, 14(1), 31-37. (in Chinese with English abstract)[文海燕, 赵哈林, 傅华 (2005). 开垦和封育年限对退化沙质草地土壤性状的影响. 草业学报, 14(1), 31-37.]
[50]	Xu DD, Guo XL (2015). Evaluating the impacts of nearly 30 years of conservation on grassland ecosystem using Landsat TM images. Grassland Science, 61, 227-242.
[51]	Yang JC, Han XG, Huang JH, Pan QM (2003). Effects of land use change on carbon storage in terrestrial ecosystem. Chinese Journal of Applied Ecology, 14, 1385-1390. (in Chinese with English abstract)[杨景成, 韩兴国, 黄建辉, 潘庆民 (2003). 土地利用变化对陆地生态系统碳贮量的影响. 应用生态学报, 14, 1385-1390.]
[52]	Yeo JJ (2005). Effects of grazing exclusion on rangeland vegetation and soils, East Central Idaho. Western North American Naturalist, 65, 91-102.
[53]	Zhang CX, Nan ZB (2010). Research progress OR effects of grazing on physical and chemical characteristics of grassland soil. Scientia Agricultura Sinica, 19(4), 204-211. (in Chinese with English abstract)[张成霞, 南志标 (2010). 放牧对草地土壤理化特性影响的研究进展. 草业学报, 19(4), 204-211.]
[54]	Zhang D, Hui D, Luo Y, Zhou G (2008). Rates of litter decom- position in terrestrial ecosystems: Global patterns and controlling factors. Journal of Plant Ecology, 1(2), 85-93.
[55]	Zhang K, Cheng X, Dang H, Ye C, Zhang YL, Zhang QF (2013). Linking litter production, quality and decomposition to vegetation succession following agricultural abandonment. Soil Biology & Biochemistry, 57, 803-813.
[56]	Zhang YB, Luo P, Sun G, Mou CX, Wang ZY, Wu N, Luo GR (2012). Effects of grazing on litter decomposition in two alpine meadow on the eastern Qinghai-Tibet Plateau. Acta Ecologica Sinica, 32, 4605-4617. (in Chinese with English abstract)[张艳博, 罗鹏, 孙庚, 牟成香, 王志远, 吴宁, 罗光荣 (2012). 放牧对青藏高原东部两种典型高寒草地类型凋落物分解的影响. 生态学报, 32, 4605-4617.]
[57]	Zuo WQ, Wang YH, Wang FY, Shi GX (2009). Effects of enclosure on the community characteristics of Leymus chinensis in degenerated steppe. Scientia Agricultura Sinica, 18(3), 12-19. (in Chinese with English abstract)[左万庆, 王玉辉, 王风玉, 师广旭 (2009). 围栏封育措施对退化羊草草原植物群落特征影响研究. 草业学报, 18(3), 12-19.]