Tradeoffs and thresholds in the effects of nitrogen addition on biodiversity and ecosystem functioning: evidence from inner Mongolia Grasslands

Global Change Biology - Tập 16 Số 1 - Trang 358-372 - 2010
Yongfei Bai1, Jianguo Wu2,3, Christopher M. Clark2, Shahid Naeem4, Qingmin Pan1, Jianhui Huang1, Lixia Zhang1, Xingguo Han1
1State Key Laboratory of Vegetation and Environmental Change,#N#Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
2School of Life Sciences and Global Institute of Sustainability, Arizona State University, Tempe, Arizona 85287-4501, USA,
3State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
4Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA

Tóm tắt

AbstractNitrogen (N) deposition is widely considered an environmental problem that leads to biodiversity loss and reduced ecosystem resilience; but, N fertilization has also been used as a management tool for enhancing primary production and ground cover, thereby promoting the restoration of degraded lands. However, empirical evaluation of these contrasting impacts is lacking. We tested the dual effects of N enrichment on biodiversity and ecosystem functioning at different organizational levels (i.e., plant species, functional groups, and community) by adding N at 0, 1.75, 5.25, 10.5, 17.5, and 28.0 g N m−2 yr−1 for four years in two contrasting field sites in Inner Mongolia: an undisturbed mature grassland and a nearby degraded grassland of the same type. N addition had both quantitatively and qualitatively different effects on the two communities. In the mature community, N addition led to a large reduction in species richness, accompanied by increased dominance of early successional annuals and loss of perennial grasses and forbs at all N input rates. In the degraded community, however, N addition increased the productivity and dominance of perennial rhizomatous grasses, with only a slight reduction in species richness and no significant change in annual abundance. The mature grassland was much more sensitive to N‐induced changes in community structure, likely as a result of higher soil moisture accentuating limitation by N alone. Our findings suggest that the critical threshold for N‐induced species loss to mature Eurasian grasslands is below 1.75 g N m−2 yr−1, and that changes in aboveground biomass, species richness, and plant functional group composition to both mature and degraded ecosystems saturate at N addition rates of approximately 10.5 g N m−2 yr−1. This work highlights the tradeoffs that exist in assessing the total impact of N deposition on ecosystem function.

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Tài liệu tham khảo

10.1146/annurev.energy.29.062403.102142

10.1038/nature02850

10.1890/07-0992.1

Barrett JE, 2002, Abiotic nitrogen uptake in semiarid grassland soils of the U.S. Great Plains, Soil Science Society of America Journal, 66, 979, 10.2136/sssaj2002.9790

Bobbink R, 2002, Empirical Critical Loads for Nitrogen, 40

10.1046/j.1365-2745.1998.8650717.x

10.1890/1051-0761(2006)016[1183:NCLFAV]2.0.CO;2

10.1007/s10021-007-9058-3

10.1111/j.1365-2664.2006.01251.x

Chen SH, 2001, Root Systems of Grassland Plants in Northern China

10.1111/j.1461-0248.2007.01053.x

10.1038/nature06503

10.1126/science.280.5364.745

10.1890/1051-0761(2001)011[0343:GMACIG]2.0.CO;2

10.1046/j.1365-2486.2003.00592.x

10.1111/j.1654-1103.2004.tb02266.x

10.1007/BF00054662

10.1029/95GB00158

10.1034/j.1600-0706.2000.890302.x

10.1126/science.289.5480.762

10.1126/science.286.5442.1123

10.1007/BF01007582

Inner Mongolia Soil Census Office, Inner Mongolia Soil and Fertilizer Service, 1994, The Soils of Inner Mongolia

10.2307/1938801

10.2136/sssaj2000.6441503x

10.2307/1312895

10.1126/science.291.5503.481

10.1023/A:1017529816140

10.1007/BF00349810

10.1890/06-2057.1

10.1007/s10533-007-9142-y

Li YH, 1988, The divergence and convergence of Aneurolepidium chinense steppe and Stipa grandis steppe under the grazing influence in Xilin river valley, Inner Mongolia, Acta Phytoecologica et Geobotanica Sinica, 12, 189

Li YQ, 2002, Changes of species diversity in succession of plant community of abandoned land in typical steppe, Journal of Inner Mongolia Agricultural University (Natural Science Edition), 23, 26

10.1111/j.1365-2486.2008.01728.x

10.1023/A:1023376905096

10.1007/BF01007574

Millennium Ecosystem Assessment, 2005, Ecosystems and Human Well‐being: Synthesis

10.2307/2261256

Mulvaney RL, 1996, Methods of Soil Analysis. Part 3. Chemical Methods, 1123

10.1111/j.1523-1739.1998.96379.x

NEGTAP(2001) Transboundary Air Pollution: Acidification Eutrophication and Ground Level Ozone in the UK. In. Department Environment Food and Rural Affairs London

Nilsson J, 1988, Critical loads for sulphur and nitrogen (Report 1988:15)

10.1038/416084a

10.1046/j.1365-2486.2003.00660.x

Reynolds JF, 2002, Global Desertification: Do Humans Cause Deserts?

10.1890/0012-9658(1998)079[0165:HEOPAN]2.0.CO;2

10.1046/j.1365-2494.1999.00166.x

10.1046/j.1461-0248.2003.00454.x

10.1126/science.1094678

10.1073/pnas.0408648102

10.1016/j.tree.2003.10.005

10.2307/2937080

10.2307/1939572

10.1038/367363a0

10.1038/nature04742

10.1038/379718a0

Vitousek PM, 1997, Human alteration of the global nitrogen cycle, Ecological Applications, 7, 737

10.1007/BF00002772

10.1126/science.274.5293.1720

White R, 2000, Pilot Analysis of Global Ecosystems: Grassland Ecosystems

Xu ZX, 1994, Study on patterns of carbohydrate reserves in Inner Mongolia steppe, Acta Prataculturae Sinica, 3, 27

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Global Change Biology

Tập 16 Số 1

358-372

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