Effects of litter quality and climate change along an elevational gradient on litter decomposition of subalpine forests, Eastern Tibetan Plateau, China

Abstract

Temperature and freeze-thaw events are two key factors controlling litter decomposition in cold biomes. Predicted global warming and changes in freeze-thaw cycles therefore may directly or indirectly impact litter decomposition in those ecosystems. Here, we conducted a 2-year-long litter decomposition experiment along an elevational gradient from 3000 to 3600 m to determine the potential effects of litter quality, climate warming and freeze-thaw on the mass losses of three litter types [dragon spruce (Picea asperata Mast.), red birch (Betula albosinensis Burk.), and minjiang fir (Abies faxoniana Rehd. et Wild)]. Marked differences in mass loss were observed among the litter types and sampling dates. Decay constant (k) values of red birch were significantly higher than those of the needle litters. However, mass losses between elevations did not differ significantly for any litter type. During the winter, lost mass contributed 18.3–28.8 % of the net loss rates of the first year. Statistical analysis showed that the relationships between mass loss and litter chemistry or their ratios varied with decomposition periods. Our results indicated that short-term field incubations could overestimate the k value of litter decomposition. Considerable mass was lost from subalpine forest litters during the wintertime. Potential future warming may not affect the litter decomposition in the subalpine forest ecosystems of eastern Tibetan Plateau.

Keywords

Alpine forest / Elevational gradient / Freeze-thaw / Global warming / Mass losses

References

[1] Aerts R. Climate, leaf litter chemistry and leaf litter decomposition in terrestrial ecosystems: a triangular relationship. Oikos, 1997, 79: 439-449.

[2] Aerts R. The freezer defrosting: global warming and litter decomposition rates in cold biomes. J Ecol, 2006, 94: 713-724.

[3] Aerts R, Caluwe HD. Nutritional and plant mediated control son leaf litter decomposition. Ecology, 1997, 78: 244-260.

[4] Bao SHD. Agriculture soil chemical analysis. 1999, Beijing: Science Press, 263 271

[5] Berg B, Berg MP, Bottner P, Box E, Breymeyer A, CadeAnta R, Couteaux M, Escudero A, Gallardo A, Kratz W, Madeira M, Mälkönen E, McClaugherty C, Meentemeyer V, Munoz F, Piussi P, Remacle J, Vide Santo A. Litter mass loss in pine forests of Europe and Eastern United States: some relationships with climate and litter quality. Biogeochemistry, 1993, 20: 127-159.

[6] Bocock KL, Gilbert OJW. The disappearance of leaf litter under different woodland conditions. Plant Soil, 1957, 9: 179-185.

[7] Cornelissen JHC, Van Bodegom PM, Aerts R, Callaghan TV, Van Logtestijn RSP, Alatalo J, Chapin FS, Gerdol R, Gudmundsson J, Gwynnjones D, Hartley AE, Hik DS, Hofgaard A, Jónsdóttir JS, Karlsson S, Klein JA, Laundra J, Magnusson B, Michelsen A, Molau U, Onipchenko VG, Quested HM, Sandvik SM, Schmidt IK, Shaver GR, Solheim B, Soudzilovskaia NA, Stenström A, Tolvanen A, Totland Ø, Wada N, Welker JM, Zhao XQ, Team MOL. Global negative vegetation feedback to climate warming responses of litter decomposition rates in cold biomes. Ecol Lett, 2007, 10: 619-627.

[8] Cramer WA. Global response of terrestrial ecosystem structure and function to CO₂ and climate change: results from six dynamic global vegetation models. Glob Change Biol, 2001, 7: 357-373.

[9] Deng RJ, Yang WQ, Feng RF, Hu JL, Qin JL, Xiong XJ. Mass loss and element release of litter in the subalpine forest over one freeze-thaw season. Acta Ecol Sin, 2009, 29: 5730-5735.

[10] Gong Z, Zhang G, Chen Z. Pedogenesis and soil taxonomy. 2007, Beijing: Science Press (In Chinese)

[11] Hobbie S, Chapin IIIFS. Winter regulation of tundra litter carbon and nitrogen dynamics. Biogeochemistry, 1996, 35: 327-338.

[12] IPCC (2007) Climate change 2007: the physical science basis. Working Group I contribution to the IPCC fourth assessment report

[13] Konestabo HS, Michelsen A, Holmstrup M. Responses of springtail and mite populations to prolonged periods of soil freeze-thaw cycles in a sub-arctic ecosystem. Appl Soil Ecol, 2007, 36: 136-146.

[14] Liu Q, Lin B. Effects of global climate change on subalpine coniferous forest trees. 2009, Beijing: Science Press (In Chinese)

[15] Lu RK. Soil and agro-chemical analytical methods. 1999, Beijing: China Agricultural Science and Technology Press (In Chinese)

[16] Luo C, Xu G, Chao Z, Wang S, Lin X, Hu Y, Zhang Z, Duan J, Chang X, Su A, Li Y, Zhao X, Du M, Tang Y, Kimball B. Effect of warming and grazing on litter mass loss and temperature sensitivity of litter and dung mass loss on the Tibetan plateau. Glob Change Biol, 2009, 6: 1-12.

[17] Monson RK, Turnipseed AA, Sparks JP. Carbon sequestration in a high-elevation, subalpine forest. Glob Change Biol, 2002, 8: 459-478.

[18] Murphy KL, Klopatek JM, Klopatek CC. The effects of litter quality and climate on decomposition along an elevational gradient. Ecol Appl, 1998, 8: 1061-1071.

[19] Olson JS. Energy storage and the balance of produces and decomposers in ecological systems. Ecol, 1963, 44: 322-332.

[20] Robinson CH. Controls on decomposition and soil nitrogen availability at high latitudes. Plant Soil, 2002, 242: 65-81.

[21] Robinson CH, Wookey PA, Parsons AN. Responses of plant litter decomposition and nitrogen mineralization to simulated environmental change in a high arctic polar semi-desert and a subarctic dwarf shrub heath. Oikos, 1995, 74: 503-512.

[22] Ruark GA. Modeling soil temperature effects on in situ decomposition rates for fine roots of loblolly pine. For Sci, 1993, 9: 118-129.

[23] Rustad LE, Fernandez IJ. Soil warming: consequences for foliar litter decay in a spruce-fir forest in Maine, USA. Soil Sci Soc Am J, 1998, 62: 1072-1080.

[24] Saleska SR. Plant community composition mediates both large transient decline and predicted long-term recovery of soil carbon under climate warming. Glob Biogeochem Cycles, 2002

[25] Sanchez FG. Loblolly pine needle decomposition and nutrient dynamics as affected by irrigation, fertilization, and substrate quality. For Ecol Manag, 2001, 152: 85-96.

[26] Scowcroft PG, Turner DR, Vitousek PM. Decomposition of Metrosideros polymorpha leaf litter along elevational gradients in Hawaii. Glob Change Biol, 2000, 6: 73-85.

[27] Shaw MR, Harte J. Control of litter decomposition in a subalpine meadow sagebrush ecotone under climate change. Ecol Appl, 2001, 11: 1206-1223.

[28] Sjögersten S, Wookey PA. Decomposition of mountain birch leaf litter at the forest-tundra ecotone in the Fennoscandian mountains in relation to climate and soil conditions. Plant Soil, 2004, 262: 215-227.

[29] Sjursen H, Michelsen A, Holmstrup M. Effects of freeze-thaw cycles on microarthropods and nutrient availability in a sub-Arctic soil. Appl Soil Ecol, 2005, 28: 79-93.

[30] Su A, Lin Q, Li Y, Du M. Effects of litter quality and climate change along an elevation gradient on litter mass loss in an alpine meadow ecosystem on the Tibetan plateau. Plant Ecol, 2010, 209: 257-268.

[31] Suzuki S, Ishizuka S, Kitamura K. Continuous estimation of winter carbon dioxide efflux from the snow surface in a deciduous broadleaf forest. J Geophys Res, 2006

[32] Tan B, Wu FZ, Yang WQ. Soil hydrolase characteristics in late soil-thawing period in subalpine/alpine forests of west Sichuan. Chin J Appl Ecol, 2011, 22: 1162-1168.

[33] Taylor BR, Jones HG. Litter decomposition under snow in a balsam fir forest. Can J Bot, 1990, 68: 112-120.

[34] Uchida M, Mo W, Nakatsubo T. Microbial activity and litter decomposition under snow cover in a cool-temperate broad-leaved deciduous forest. Agric For Meteorol, 2005, 134: 102-109.

[35] Vanderbilt KL, White CS, Hopkins O. Aboveground decomposition in arid environments: results of a long-term study in central New Mexico. J Arid Environ, 2008, 72: 696-709.

[36] Verburg PSJ, Van Loon WKP, Lükewille A. The CLIMEX soil-heating experiment: soil response after 2 years of treatment. Biol Fertil Soils, 1999, 28: 271-276.

[37] Wang W, Peng S, Wang T. Winter soil CO₂ efflux and its contribution to annual soil respiration in different ecosystems of a forest-steppe ecotone, north China. Soil Biol Biochem, 2010, 42: 451-458.

[38] Xiong L, Xu Z, Yang W, Yin R, Tang S, Xu L, Chang C. Aboveground litter contribution to soil respiration in a subalpine dragon spruce plantation of western Sichuan. Acta Ecol Sin, 2015

[39] Xu Z, Wan C, Xiong P, Tang Z, Hu R, Cao G, Liu Q. Initial responses of soil CO₂ efflux and C, N pools to experimental warming in two contrasting forest ecosystems, Eastern Tibetan Plateau, China. Plant Soil, 2010, 336: 183-195.

[40] Xu ZF, Tang Z, Wan C, Xiong P, Cao G, Liu Q. Effects of experimental warming on soil enzyme activities in two coniferous forests, Western Sichuan. Chin J Appl Ecol, 2010, 21: 2727-2733.

[41] Xu Z, Pu X, Yin H, Zhao C, Liu Q, Wu F. Warming effects on the early decomposition of three litter types, Eastern Tibetan Plateau, China. Eur J Soil Sci, 2012, 63: 360-367.

[42] Zhang DQ, Hui DF, Luo YQ. Rates of litter decomposition in terrestrial ecosystems: global patterns and controlling factors. J Plant Ecol, 2008, 6: 85-93.

[43] Zhou G, Guan L, Wei X, Tang X, Liu S, Liu J, Zhang D, Yan J. Factors influencing leaf litter decomposition: an intersite decomposition experiment across China. Plant Soil, 2008, 311: 61-72.

[44] Zhou FF, Lin B, Liu Q. Soil respiration of subalpine coniferous forest in winter in the east of the Qinghai–Tibet Plateau, China. Chin J Appl Environ Biol, 2009, 15: 761-767.