| Research Articles |
|
|
|
|
| Competition between Populus euphratica and Tamarix ramosissima seedlings under simulated high groundwater availability |
| WU Guilin1,2, JIANG Shaowei1,2, LIU Weiyang3, ZHAO Chengyi1, LI Jun1* |
1 State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China;
2 University of Chinese Academy of Sciences, Beijing 100049, China;
3 College of Plant Science, Tarim University, Alar 843300, China |
|
|
|
Abstract Desert riparian plants experience high variability in water availability due to hydrological fluctuations. How riparian plants can survive with low water availability has been well studied, however, little is known about the effects of high water availability on plant community structuring. We conducted a mesocosm experiment to test whether seedling competition under simulated high groundwater availability can explain the shift of co-dominance of Populus euphratica and Tamarix ramosissima in early communities to P. euphratica dominance in mature ones along the Tarim River in northwestern China. Seedlings of these two plant species were grown in monoculture and mixture pools with high groundwater availability. Results indicated that the above-ground biomass and relative yield of T. ramosissima were higher than those of P. euphratica. The competitive advantages of T. ramosissima included its rapid response in growth to groundwater enrichment and its water spender strategy, as evidenced by the increased leaf biomass proportion and the inert stomatal response to leaf-to-air vapor pressure deficit (VPD). In comparison, P. euphratica showed a conservative strategy in water use, with a sensitive response to leaf-to-air VPD. Result of the short-term competition was inconsistent with the long-term competition in fields, suggesting that competition exclusion is not the mechanism structuring the desert riparian plant communities. Thus, our research highlights the importance of mediation by environmental fluctuations (such as lessening competition induced by disturbance) in structuring plant communities along the Tarim riparian zones.
|
|
Received: 23 July 2015
Published: 01 April 2016
|
| Fund: This research was funded by the National Basic Research Program of China (2013CB429903) and the National Natural Science Foundation of China (41171037, 41171095). |
|
Corresponding Authors:
|
|
|
| Aasamaa K, Sõber A. 2011. Stomatal sensitivities to changes in leaf water potential, air humidity, CO2 concentration and light intensity, and the effect of abscisic acid on the sensitivities in six temperate deciduous tree species. Environmental and Experimental Botany, 71(1): 72–78.Addington R N, Mitchell R J, Oren R, et al. 2003. Stomatal sensitivity to vapor pressure deficit and its relationship to hydraulic conductance in Pinus palustris. Tree Physiology, 24(5): 561–569.Barrat-Segretain M H. 2001. Biomass allocation in three macrophyte species in relation to the disturbance level of their habitat. Freshwater Biology, 46(7): 935–945.Bhattacharjee J, Taylor Jr J P, Smith L M, et al. 2009. Seedling competition between native cottonwood and exotic saltcedar: implications for restoration. Biological Invasions, 11(8): 1777–1787. Biswas S R, Mallik A U. 2010. Disturbance effects on species diversity and functional diversity in riparian and upland plant communities. Ecology, 91(1): 28–35. Bottollier-Curtet M, Planty-Tabacchi A M, Tabacchi E. 2013. Competition between young exotic invasive and native dominant plant species: implications for invasions within riparian areas. Journal of Vegetation Science, 24(6): 1033–1042. Bovard B D, Curtis P S, Vogel C S, et al. 2005. Environmental controls on sap flow in a northern hardwood forest. Tree Physiology, 25(1): 31–38. Buckley T N. 2005. The control of stomata by water balance. New Phytologist, 168(2): 275–292. Busch D E, Smith S D. 1995. Mechanisms associated with decline of woody species in riparian ecosystems of the Southwestern U.S. Ecological Monographs, 65(3): 347–370. Chen Y N, Xu C C, Chen Y P, et al. 2013. Progress, challenges and prospects of eco-hydrological studies in the Tarim River Basin of Xinjiang, China. Environmental Management, 51(1): 138–153. Chen Y P, Chen Y N, Xu C C, et al. 2011. Effects of groundwater depth on the gas exchange and chlorophyll fluorescence of Populus euphratica in the lower reaches of Tarim River. Acta Ecologica Sinica, 31(2): 344–353. (in Chinese) Chesson P, Huntly N. 1997. The roles of harsh and fluctuating conditions in the dynamics of ecological communities. The American Naturalist, 150(5): 519–553. Cleverly J R, Smith S D, Sala A, et al. 1997. Invasive capacity of Tamarix ramosissima in a Mojave Desert floodplain: the role of drought. Oecologia, 111(1): 12–18. Connell J H. 1983. On the prevalence and relative importance of interspecific competition: evidence from field experiments. The American Naturalist, 122(5): 661-696. Corenblit D, Steiger J, Gurnell A M, et al. 2009. Plants intertwine fluvial landform dynamics with ecological succession and natural selection: a niche construction perspective for riparian systems. Global Ecology and Biogeography, 18(4): 507–520. Fowler N. 1986. The role of competition in plant communities in arid and semiarid regions. Annual Review of Ecology and Systematics, 17: 89–110. Fredeen A L, Sage R F. 1999. Temperature and humidity effects on branchlet gas-exchange in white spruce: an explanation for the increase in transpiration with branchlet temperature. Trees, 14(3): 161–168. Friedman J M, Lee V J. 2002. Extreme floods, channel change, and riparian forests along ephemeral streams. Ecological Monographs, 72(3): 409–425. Fu A H, Chen Y N, Li W H. 2006. Analysis on water potential of Populus euphratica oliv and its meaning in the lower reaches of Tarim River, Xinjiang. Chinese Science Bulletin, 51(Suppl. 1): 221–228. Gasith A, Resh V H. 1999. Streams in Mediterranean climate regions: abiotic influences and biotic responses to predictable seasonal events. Annual Review of Ecology and Systematics, 30: 51–81. Glenn E P, Nagler P L. 2005. Comparative ecophysiology of Tamarix ramosissima and native trees in western U.S. riparian zones. Journal of Arid Environments, 61(3): 419-446.Gries D, Zeng F, Foetzki A, et al. 2003. Growth and water relations of Tamarix ramosissima and Populus euphratica on Taklamakan desert dunes in relation to depth to a permanent water table. Plant, Cell and Environment, 26(5): 725–736. Han L, Wang H Z, Zhou Z L, et al. 2007. Population structure and demography of Populus euphraticu in upper and middle reaches of Tarim River. Acta Ecologica Sinica, 27(4): 1315-1322. (in Chinese) Hutchinson G E. 1961. The paradox of the plankton. The American Naturalist, 95(882): 137–145. Kotowski W, Beauchard O, Opdekamp W, et al. 2010. Waterlogging and canopy interact to control species recruitment in floodplains. Functional Ecology, 24(4): 918–926. Körner C, Stöcklin J, Reuther-Thiébaud L, et al. 2008. Small differences in arrival time influence composition and productivity of plant communities. New Phytologist, 177(3): 698–705. Li J, Yu B, Zhao C, et al. 2013. Physiological and morphological responses of Tamarix ramosissima and Populus euphratica to altered groundwater availability. Tree Physiology, 33(1): 57–68. Lytle D A, Poff N L. 2004. Adaptation to natural flow regimes. Trends in Ecology and Evolution, 19(2): 94–100. Ma J X, Chen Y N, Li W H, et al. 2010. Response of sap flow in Populus euphratica to changes in groundwater depth in the middle and lower reaches of the Tarim River of northwestern China. Chinese Journal of Plant Ecology, 34(8): 915–923. (in Chinese) Merritt D M, Poff N L R. 2010. Shifting dominance of riparian Populus and Tamarix along gradients of flow alteration in western North American rivers. Ecological Applications, 20(1): 135–152. Mott K A, Peak D. 2010. Stomatal responses to humidity and temperature in darkness. Plant, Cell and Environment, 33(7): 1084–1090. Naiman R J, Décamps H. 1997. The ecology of interfaces: riparian zones. Annual Review of Ecology and Systematics, 28: 621–658. Ocheltree T W, Nippert J B, Prasad P V V. 2013. Stomatal responses to changes in vapor pressure deficit reflect tissue-specific differences in hydraulic conductance. Plant, Cell and Environment, 37(1): 132–139. Pollock M M, Naiman R J, Hanley T A. 1998. Plant species richness in riparian wetlands–a test of biodiversity theory. Ecology, 79(1): 94–105. Rood S B, Patiño S, Coombs K, et al. 2000. Branch sacrifice: cavitation-associated drought adaptation of riparian cottonwoods. Trees, 14(5): 248–257. Sabo J L, Sponseller R, Dixon M, et al. 2005. Riparian zones increase regional species richness by harboring different, not more, species. Ecology, 86(1): 56–62. Sala A, Smith S D, Devitt D A. 1996. Water use by Tamarix ramosissima and associated phreatophytes in a Mojave desert floodplain. Ecological Applications, 6(3): 888–898. Scott M L, Friedman J M, Auble G T. 1996. Fluvial process and the establishment of bottomland trees. Geomorphology, 14(4): 327–339. Sher A A, Marshall D L. 2003. Seedling competition between native Populus deltoides (Salicaceae) and exotic Tamarix ramosissima (Tamaricaceae) across water regimes and substrate types. American Journal of Botany, 90(3): 413–422. Sher A A, Marshall D L, Taylor J P. 2002. Establishment patterns of native Populus and Salix in the presence of invasive nonnative Tamarix. Ecological Applications, 12(3): 760–772. Sher A A, Marshall D L, Gilbert S A. 2000. Competition between native Populus deltoides and invasive Tamarix ramosissima and the implications for reestablishing flooding disturbance. Conservation Biology, 14(6): 1744–1754. Sparks J P, Black R A. 1999. Regulation of water loss in populations of Populus trichocarpa: the role of stomatal control in preventing xylem cavitation. Tree Physiology, 19(7): 453–459. Stella J C, Battles J J. 2010. How do riparian woody seedlings survive seasonal drought? Oecologia, 164(3): 579–590. Stella J C, Rodríguez-González P M, Dufor S, et al. 2013. Riparian vegetation research in Mediterranean-climate regions: common patterns, ecological processes, and considerations for management. Hydrobiologia, 719(1): 291–315. Stromberg J. 1998. Dynamics of Fremont cottonwood (Populus fremontii) and saltcedar (Tamarix chinensis) populations along the San Pedro River, Arizona. Journal of Arid Environments, 40(2): 133–155. Stromberg J C, Lite S J, Marler R, et al. 2007. Altered stream-flow regimes and invasive plant species: the Tamarix case. Global Ecology and Biogeography, 16(3): 381–393. Tiegs S D, O’Leary J F, Pohl M M, et al. 2005. Flood disturbance and riparian species diversity on the Colorado River Delta. Biodiversity and Conservation, 14(5): 1175–1194. Vandersande M W, Glenn E P, Walworth J L. 2001. Tolerance of five riparian plants from the lower Colorado River to salinity drought and inundation. Journal of Arid Environments, 49(1): 147–159. Weigelt A, Jolliffe P. 2003. Indices of plant competition. Journal of Ecology, 91(5): 707–720. Zhang X W, Cheng T F, Chen H W, et al. 2007. Underground water monitoring and analysis on Tarim River Basin. Journal of Shihezi University: Natural Science, 25(3): 364–368. (in Chinese) Zhang Y M, Chen Y N, Pan B R. 2005. Distribution and floristics of desert plant communities in the lower reaches of Tarim River, southern Xinjiang, People’s Republic of China. Journal of Arid Environments, 63(4): 772–784. Zhou H H, Chen Y N, Li W H, et al. 2013. Xylem hydraulic conductivity and embolism in riparian plants and their responses to drought stress in desert of Northwest China. Ecohydrology, 6(6): 984–993. |
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
