| Research Articles |
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| Gas exchange of Populus euphratica leaves in a riparian zone |
| Dieter OVERDIECK1*, Daniel ZICHE2, RuiDe YU3 |
1 Institute of Ecology/Ecology of Woody Plants, TU-Berlin, D-14195 Berlin, Germany;
2 von Thuenen-Institut, Institute of Forest Ecology and Forest Inventory, D-16225 Eberswalde, Germany;
3 Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China |
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Abstract Riparian vegetation belts in arid regions of Central Asia are endangered to lose their ecosystem ser-vices due to intensified land use. For the development of sustained land use, management knowledge of plant performance in relation to resource supply is needed. We estimated productivity related functional traits at the edges of the habitat of Populus euphratica Oliv. Specific leaf area (SLA) and carbon/nitrogen (C/N) ratio of P. euphratica leaves growing near a former river bank and close to moving sand dunes in the Ebinur Lake National Nature Reserve in Xinjiang, Northwest China (near Kazakhstan) were determined and daily courses of CO2 net as-similation (PN), transpiration (E), and stomatal conductance (gs) of two consecutive seasons were measured during July–August 2007 and June–July 2008. Groundwater level was high (1.5–2.5 m below ground) throughout the years and no flooding occurred at the two tree stands. SLA was slightly lower near the desert than at the former river bank and leaves contained less N in relation to C. Highest E and gs of P. euphratica were reached in the morning before noon on both stands and a second low maximum occurred in the afternoon despite of the unchanged high levels of air to leaf water vapor pressure deficit (ALVPD). Decline of gs in P. euphratica was followed by decrease of E. Water use efficiency (WUE) of leaves near the desert were higher in the morning and the evening, in contrast to leaves from the former river bank that maintained an almost stable level throughout the day. High light compensation points and high light saturation levels of PN indicated the characteristics of leaves well-adapted to intensive irradiation at both stands. In general, leaves of P. euphratica decreased their gs beyond 20 Pa/kPa ALVPD in order to limit water losses. Decrease of E did not occur in both stands until 40 Pa/kPa ALVPD was reached. Full stomatal closure of P. euphratica was achieved at 60 Pa/kPa ALVPD in both stands. E through the leaf surface amounted up to 30% of the highest E rates, indicating dependence on water recharge from the ground despite of obviously closed stomata. A distinct leaf surface temperature (Tleaf) threshold of around 30°C also existed before stomata started to close. Generally, the differences in gas exchange between both stands were small, which led to the conclusion that micro-climatic constraints to E and photosynthesis were not the major factors for declining tree density with increasing distance from the river.
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Received: 27 November 2012
Published: 06 December 2013
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| Fund: The German Academic Exchange Service, PPP-China (D/06/00362). |
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| Aphalo P J, Jarvis P G. 1991. Do stomata respond to relative humidity? Plant, Cell & Environment, 14(1): 127–132.Arndt S K, Arampatsis C, Foetzki A, et al. 2004. Contrasting patterns of leaf solute accumulation and salt adaptation in four phreatophytic desert plants in a hyperarid desert with saline groundwater. Journal of Arid Environments, 59(2): 259–270.Bogeat-Triboulot M B, Brosché M, Renaut J, et al. 2007. Gradual soil water depletion results in reversible changes of gene expression, protein profiles, ecophysiology, and growth performance in Populus euphratica, a poplar growing in arid regions. Plant Physiology, 143(2): 876–892.Bruelheide H, Vonlanthen B, Jandt U, et al. 2010. Life on the edge–to which degree does phreatic water sustain vegetation in the periphery of the Taklamakan Desert? Applied Vegetation Science, 13(1): 56–71.Cao S K, Feng Q, Su Y H, et al. 2011. Research on the water use efficiency and foliar nutrient status of Populus euphratica and Tamarix ramosissima in the extreme arid region of China. Environmental Earth Sciences, 62(8): 1597–1607.Chang Y, Chen S L, Yin W L, et al. 2006. Growth, gas exchange, abscisic acid and calmodulin response to salt stress in three poplars. Journal of Integrative Plant Biology, 48(3): 286–293.Chen S L, Li J K, Wang S S, et al. 2001. Salt, nutrient uptake and transport, and ABA of Populus euphratica; a hybrid in response to increasing soil NaCl. Trees, 15(3): 186–194.Chen S L, Li J K, Fritz E, et al. 2002. Sodium and chloride distribution in roots and transport in three poplar genotypes under increasing NaCl stress. Forest Ecology and Management, 168(1–3): 217–230.Chen S L, Li J K, Wang T H, et al. 2003. Gas exchange, xylem ions and abscisic acid response to Na+–salts and Cl––salts in Populus euphratica. Acta Botanica Sinica, 45(5): 561–566. Chen Y N, Zilliacus H, Li W H. 2006a. Ground-water level effects plant species diversity along the lower reaches of the Tarim River. Journal of Arid Environments, 66(2): 231–246.Chen Y P, Chen Y N, Li W H, et al. 2006b. Characterization of photosynthesis of Populus euphratica grown in the arid region. Photosynthetica, 44(4): 622–626.Farquhar G D. 1978. Feedforward responses of stomata to humidity. Australian Journal of Plant Physiology, 5(6): 787–800.Fu A H, Li W H, Chen Y N, et al. 2011. Analysis of dominant factors influencing moisture change of broad-ovate leaves of Populus euphratica Oliv. in extremely arid region. Photosynthetica, 49(2): 295–308.Fung L E, Wang S S, Altman A, et al. 1998. Effect of NaCl on growth, photosynthesis ion and water relations of four poplar genotypes. Forest Ecology and Management, 107(1–3): 135–146.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 & Environment, 26(5): 725–736.Gries D, Foetzki A, Arndt S K, et al. 2005. Production of perennial vegetation in an oasis desert transition zone in NW China–allometric estimation, and assessment of flooding and use effects. Plant Ecology, 181(1): 23–43.Hukin D, Cochard H, Dreyer E, et al. 2005. Cavitation vulnerability in roots and shoots: does Populus euphratica Oliv., a poplar from arid areas of Central Asia, differ from other poplar species? Journal of Experimental Botany, 56(418): 2003–2010. Khamzina A, Lamers J P A, Vlek P L G. 2008. Tree establishment under deficit irrigation on degraded agricultural land in the lower Amu Darya River region, Aral Sea Basin. Forest Ecology and Manage-ment, 255(1): 168–178.Lamers J P A, Khamzina A, Worbes M. 2006. The analyses of physiological and morphological attributes of 10 tree species for early determination of their suitability to afforest degraded landscapes in the Aral Sea Basin of Uzbekistan. Forest Ecology and Management, 221(1–3): 249–259.Larchevêque M, Maurel M, Desrochers A, et al. 2011. How does drought tolerance compare between two improved hybrids of balsam poplar and an unimproved native species? Tree Physiology, 31(3): 240–249.Ma H C, Fung L, Wang S S, et al. 1997. Photosynthetic response of Populus euphratica to salt stress. Forest Ecology and Management, 93(1–2): 55–61.Meinzer F C, Grantz D A. 1991. Coordination of stomatal, hydraulic and canopy boundary layer properties: do stomata balance conductances by measuring transpiration? Physiologia Plantarum, 83(2): 324–329.Monclus R, Dreyer E, Villar M, et al. 2006. Impact of drought on productivity and water use efficiency in 29 genotypes of Populus deltoidis × Populus nigra. New Phytologist, 169(4): 765–777.Monteith J L. 1995. A reinterpretation of stomatal responses to humidity. Plant, Cell & Environment, 18(4): 357–364.Mott K A, Parkhurst D F. 1991. Stomatal response to humidity in air and helox. Plant, Cell & Environment, 14(5): 509–515.Otieno D O, Schmidt M W T, Kurz-Besson C, et al. 2007. Regulation of transpirational water loss in Quercus suber trees in a Mediterra-nean-type ecosystem. Tree Physiology, 27(8): 1179–1187.Säumel I, Ziche D, Yu R, et al. 2011. Grazing as a driver for Populus euphratica woodland degradation in the semi-arid Aibi Hu region, northwestern China. Journal of Arid Environments, 75(3): 265–269. Thomas F M, Arndt S K, Bruelheide H, et al. 2000. Ecological basis for sustainable management of the indigenous vegetation in a Central-Asian desert: presentation and first results. Journal of Applied Botany, 74(5–6): 212–219.Thomas F M, Foetzki A, Arndt S K, et al. 2006. Water use by perennial plants in the transition zone between river oasis and desert in NW China. Basic and Applied Ecology, 7(3): 253–267.Thomas F M, Foetzki A, Gries D, et al. 2008. Regulation of the water status in three cooccuring phreatophytes at the southern fringe of the Taklamakan desert. Journal of Plant Ecology, 1(4): 227–235.Walter H, Box E O, Hilbig W. 1983. The deserts of Central Asia. In: West N E. The Deserts of Central Asia: Temperate Deserts and Semi-Deserts. Amsterdam: Elsevier, 193–236.Yu R D. 2008. Forest development along the former river Aqikesu in the Aibi Hu National Nature Reserve in P.R. China. Ph.D. Dissertation. TU-Berlin: Technical University of Berlin.Zhao Y, Zhao C Y, Xu Z L, et al. 2012. Physiological responses of Populus euphratica Oliv. to groundwater table variations in the lower reaches of Heihe River, Northwest China. Journal of Arid Land, 4(3): 281–291.Zhou H H, Chen Y N, Li W H, et al. 2010. Photosynthesis of Populus euphratica in relation to groundwater depths and high temperature in arid environment, northwest China. Photosynthetica, 48(2): 257–268.Zhu G F, Li X, Su Y H, et al. 2010. Parametrization of coupled CO2 and H2O gas exchange model at the leaf scale of Populus euphratica. Hydrology and Earth System Sciences, 14(3): 419–431.Zhu G F, Li X, Su Y H, et al. 2011. Seasonal fluctuations and tempera-ture dependence in photosynthetic parameters and stomatal con-ductance at leaf scale of Populus euphratica Oliv. Tree Physiology, 31(2): 178–195. |
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