Effects of Caragana microphylla patch and its canopy size on “islands of fertility” in a Mongolian grassland ecosystem
Tóm tắt
In arid and semiarid regions, variations in “islands of fertility” accompanied by discontinuous vegetation is frequently observed. However, the effects of vegetation patches on soil, including the influence of canopy size, are not fully understood, particularly under conditions of severe grazing. We examined the effects of patches of mound-forming shrub, Caragana microphylla, and the plant’s canopy size on these islands of fertility in a heavily grazed Mongolian grassland. In 11 patches with various canopy sizes (32.5–180 cm in diameter), we compared the chemical properties of soils among three microsites: Mound, Below, and Around, which were inside, below, and outside of C. microphylla mounds, respectively. Total carbon (C) and most essential elements for the plants were more concentrated in Mound, but total nitrogen (N) and nonlimiting elements, such as exchangeable sodium (Na), did not significantly differ among microsites. Larger canopies more strongly affected the enrichment of total C and most essential elements, including total N, in Mound. These results suggest that C. microphylla patches substantially enrich total C and most essential elements and that the extent of enrichment was intensified with canopy size. However, under severe grazing, total N may be relatively more affected by the redistribution of resources through grazing, particularly when the canopy size is small.
Tài liệu tham khảo
Abrahams AD, Parsons AJ (1994) Hydraulics of interrill overland flow on stone-covered desert surfaces. Catena 23:111–140
Augustine DJ (2003) Spatial heterogeneity in the herbaceous layer of a semi-arid savanna. Plant Ecol 167:319–332
Barth RC (1980) Influence of pinyon pine trees on soil chemical and physical properties. Soil Sci Soc Am J 44:112–114
Bernhard-Reversat F (1982) Biogeochemical cycle of nitrogen in a semi-arid savanna. Oikos 38:321–332
Bernhard-Reversat F (1988) Soil nitrogen mineralization under a Eucalyptus plantation and a natural Acacia forest in Senegal. For Ecol Manage 23:233–244
Burke IC, Lauenroth WK, Riggle R, Brannen P, Madigan B, Beard S (1999) Spatial variability of soil properties in the shortgrass steppe: the relative importance of topography, grazing, microsite, and plant species in controlling spatial patterns. Ecosystems 2:422–438
Charley JL, West NE (1975) Plant-induced soil chemical patterns in some shrub dominated semi-desert ecosystems of Utah. J Ecol 63:945–963
Cross AF, Schlesinger WK (1999) Plant regulation of soil nutrient distribution in the northern Chihuahuan Desert. Plant Ecol 145:11–25
El-Bana MI, Nijs I, Kockelbergh F (2002) Microenvironmental and vegetational heterogeneity induced by phytogenic nebkhas in an arid coastal ecosystem. Plant Soil 247:283–293
El-Bana MI, Nijs I, Khedr A-HA (2003) The importance of phytogenic mounds (Nebkhas) for restoration of arid degraded rangelands in Northern Sinai. Restor Ecol 11:317–324
Facelli JM, Temby AM (2002) Multiple effects of shrub on annual communities in arid lands of South Australia. Austra Ecol 27:422–431
Frelich LE, Calcote RR, Davis MB, Pastor J (1993) Patch formation and maintenance in an old-growth hemlock-hardwood Forest. Ecology 74:513–527
Garner W, Steinberger Y (1989) A proposed mechanism for the formation of ‘Fertile Islands’ in the desert ecosystem. J Arid Environ 16:257–262
Hirobe M, Ohte N, Karasawa N, Zhang G, Wang L, Yoshikawa K (2001) Plant species effect on the spatial patterns of soil properties in the Mu-us desert ecosystem, Inner Mongolia, China. Plant Soil 234:195–205
Hook PB, Burke IC (2000) Biogeochemistry in a shortgrass landscape: control by topography, soil texture, and microclimate. Ecology 81:2686–2703
Hook PB, Burke IC, Lauenroth WK (1991) Heterogeneity of soil and plant N and C associated with individual plants and openings in North American shortgrass steppe. Plant Soil 138:247–256
Housman DC, Yeager CM, Darby BJ, Sanford RL Jr, Kuske CR, Neher DA, Belnap J (2007) Heterogeneity of soil nutrients and subsurface biota in a dryland ecosystem. Soil Biol Biochem 39:2138–2149
Jobbágy EG, Jackson RB (2001) The distribution of soil nutrients with depth: global patterns and imprint of plants. Biogeochemistry 53:51–77
Keeny DR, Nelson DW (1982) Nitrogen—inorganic forms. In: Page AL, Miller RH, Keeny DR (eds) Method of soil analysis, Part 2. ASA and SSSA, Madison, pp 643–698
Kelly RH, Burke IC, Lauenroth WK (1996) Soil organic matter and nutrient availability responses to reduced plant inputs in shortgrass steppe. Ecology 77:2516–2527
Klemmedson JO, Tiedemann AR (2000) Influence of western juniper development on distribution of soil and organic layer nutrients. Northwest Sci 74:1–11
Li J, Zhao C, Li Y, Wang F (2007) Effect of plant species on shrub fertile island at an oasis-desert ecotone in the South Junggar Basin, China. J Arid Environ 71:350–361
Liu LD, Zhang L, Gao YB (2004) Caragana microphylla Lam. Bull Biol 39:21–22
Ludwig F, de Kroon H, Berendse F, Prins HHT (2004) The influence of savanna trees on nutrient, water and light availability and the understorey vegetation. Plant Ecol 170:93–105
National Climate Data Center (2008) Global summary of the Day. In: National Oceanic and Atmospheric Administration. http://www.noaa.gov/
Noy-Meir I (1973) Desert ecosystems: environment and producers. Annu Rev Ecol Syst 4:25–52
Olsen SR, Sommers LE (1982) Phosphorus. In: Page AL, Miller RH, Keeny DR (eds) Methods of soil analysis, Part 2. ASA and SSSA, Madison, pp 403–430
Russelle MP (1992) Nitrogen cycling in pasture and range. J Prod Agric 5:13–23
Sasaki T, Okayasu T, Shirato Y, Undarmaa J, Takeuchi K (2007) Quantifying the resilience of plant communities under different grazing intensities in a degraded shrubland. A case study in Mandalgobi Mongolia. Grassl Sci 53:192–195
Sasaki T, Okayasu T, Shirato Y, Jamsran U, Okubo S, Takeuchi K (2008a) Can edaphic factors demonstrate landscape-scale differences in vegetation responses to grazing? Plant Ecol 194:51–66
Sasaki T, Okayasu T, Jamsran U, Takeuti K (2008b) Threshold changes in vegetation along a grazing gradient in Mongolian rangelands. J Ecol 96:145–154
Schlesinger WH, Pilmanis AM (1998) Plant–soil interactions in deserts. Biogeochemistry 42:168–187
Schlesinger WH, Reynolds JF, Cunningham GL, Huenneke LF, Jarrell WM, Virginia RA, Whitford WG (1990) Biological feedbacks in global desertification. Science 247:1043–1048
Schlesinger WH, Raikes JA, Hartley AE, Cross AF (1996) On the spatial pattern of soil nutrients in desert ecosystems. Ecology 77:364–374
Scholes RJ, Archer SR (1997) Tree–grass interactions in Savannas. Annu Rev Ecol Syst 28:517–544
StatSoft Inc. (2005) STATISTICA 06J (data analysis software system). http://www.statsoft.com
Soil Survey Staff (2006) Keys to soil taxonomy, 10th edn. USDA-Nat. Resources Conservation Services, Washington, DC, pp 332
Su YZ, Zhao HL (2003) Soil properties and plant species in an age sequence of Caragana microphylla in the Horqin Sandy Land, North China. Ecol Eng 20:223–235
Su YZ, Zhang TH, Li YL, Wang F (2005) Changes in soil properties after established of Artemisia halodendron and Caragana microphylla on shifting sand dune in semiarid Horqin Sandy Land, Northern China. Environ Manage 36:272–281
Szott LT, Fernandes ECM, Sanchez PA (1991) Soil–plant interactions in agroforestry systems. For Ecol Manage 45:127–152
Tiedemann AR, Klemmedson JO (2000) Biomass and nutrient distribution and system nutrient budget for western juniper in central Oregon. Northwest Sci 74:12–24
Tompson TL, Zaady E, Huancheng P, Wilson TB, Martens DA (2006) Soil C and N pools in patchy shrubland of the Negev and Chihuahuan deserts. Soil Biol Biochem 38:943–1955
Virginia RA (1986) Soil development under legume tree canopies. For Ecol Manage 16:69–79
Wedin DA, Tilman D (1990) Species effects on nitrogen cycling: A test with perennial grasses. Oecologia 84:433–441
Wezel A, Rajot JL, Herbrig C (2000) Influence of shrubs on soil characteristics and their function in Sahelian agro-ecosystems in semi-arid Niger. J Arid Environ 44:383–398
Xiong XG, Han XG, Bai YF, Pan QM (2003) Increased distribution of Caragana microphylla in rangelands and its causes and consequences in Xilin River Basin. Acta Pratacultural Sin 12:57–62
Yamada Y, Yamaguchi Y, Undarmaa J, Hirobe M, Yoshikawa K (2009) Environmental factors controlling leaf emergence in Caragana microphylla, a deciduous shrub of the Mongolian steppe. J Arid Land Stud 19:137–140
Zhang Z, Wang SP, Nyren P, Jiang GM (2006) Morphological and reproductive response of Caragana microphylla to different stocking rates. J Arid Environ 67:671–677
Zhao HL, Zhou RL, Su YZ, Zhang H, Zhao LY, Drake S (2007) Shrub facilitation of desert land restoration in the Horqin Sand Land of Inner Mongolia. Ecol Eng 31:1–8