Interdependent Dynamics of LAI-ET across Roofing Landscapes: the Mongolian and Tibetan Plateaus

doi:10.5814/j.issn.1674-764X.2019.03.008

Abstract

Abstract:

The Mongolian and Tibetan Plateaus have experienced warming higher than the global average in recent decades, resulting in many significant changes to ecosystem structures and functions. Among items that show change are the leaf area index (LAI) and evapotranspiration (ET), both of which play a fundamental role in shaping many causes and consequences of land surface processes and climate. This study examines the spatiotemporal changes of the LAI and ET and their relationships on these two roofing landscapes. Based on the MODIS products from 2000 through 2014, we found that there existed a general positive relationship between LAI and ET on the Mongolia Plateau (MP), while synergy did not exist on the Tibetan Plateau (TP). Overall, 49.38% (50.62%) of land areas on the TP experienced significant increases (decreases) in LAI, while on the MP the percentages of increase and decrease were 94.92% (5.09%). For ET, the increased land area was 21.70% (124100 km²) on the TP and 88.01% (341600 km²) on the MP. More importantly, the relationships varied substantially across space and over time, with mismatches found in some parts of the landscapes. Additional observational investigations and/or experimental research are needed to explore the relationships, including the influences of vegetation characteristics and disturbances.

Key words: ET, LAI, alpine, Eurasian continent, altitude and latitude, land surface process

TIAN Li. Interdependent Dynamics of LAI-ET across Roofing Landscapes: the Mongolian and Tibetan Plateaus[J]. Journal of Resources and Ecology, 2019, 10(3): 296-306.

Figures/Tables 7

Fig. 1 (a) The spatial distributions of land cover types on the two plateaus; (b) The average annual LAI during 2000-2014; (c) The average annual ET during 2000-2014; (d-e) The probability density function (PDF) for LAI and ET.

Fig. 2 Spatial distributions of the change trends for LAI in the growing season (May-September); the inset map shows significant increases (blue) and decreases (red) (P<0.05).

Fig. 3 Spatial distributions of the change trends for ET in the growing season (May-September); the inset map shows significant increases (blue) and decreases (red) (P<0.05).

Table 1 The average annual and standard deviation (std) of LAI and ET during 2000-2014 by average annual LAI class on the Mongolian Plateau (MP) and the Tibetan Plateau (TP)

Var	Loc	Sig. Area	Annual	May	June	July	August	September
LAI	TP	Total (1000 km²)	57.41	65.03	38.39	47.92	48.00	42.96
		Decreasing	29.06	3.16	6.53	19.99	18.55	31.03
		(%)	(50.62)	(4.86)	(17.01)	(41.72)	(38.65)	(72.23)
		Increasing	28.35	61.86	31.86	27.93	29.45	11.93
		(%)	(49.38)	(95.13)	(82.99)	(58.28)	(61.35)	(27.77)
	MP	Total (1000 km²)	101.93	57.12	100.63	80.81	62.59	61.36
		Decreasing	5.19	17.25	2.24	4.99	6.21	7.63
		(%)	(5.09)	(30.20)	(2.23)	(6.17)	(9.92)	(12.43)
		Increasing	96.75	39.87	98.39	75.82	56.38	53.73
		(%)	(94.92)	(69.80)	(97.77)	(93.83)	(90.08)	(87.57)
ET	TP	Total (1000 km²)	571.90	196.90	478.20	476.80	333.90	265.70
		Decreasing	447.80	154.30	332.40	278.70	295.40	250.10
		(%)	(78.30)	(78.36)	(69.51)	(58.46)	(88.47)	(94.12)
		Increasing	124.10	42.60	145.80	198.00	38.50	15.60
		(%)	(21.70)	(21.64)	(30.49)	(41.54)	(11.53)	(5.88)
	MP	Total (1000 km²)	388.20	86.10	343.30	496.80	224.60	49.80
		Decreasing	46.50	53.80	48.40	29.40	78.10	30.30
		(%)	(11.99)	(62.42)	(14.11)	(5.92)	(34.79)	(60.82)
		Increasing	341.60	32.40	294.80	467.40	146.40	19.50
		(%)	(88.01)	(37.58)	(85.89)	(94.08)	(65.21)	(39.18)

Fig. 4 The trends of the mean LAI on grasslands in the Mongolian and Tibetan plateaus

Fig. 5 The trends of the ET on the grasslands in the Mongolian and Tibetan plateaus

Fig. 6 Boxplots of MODIS ET retrieval as a function of MODIS-estimated leaf area index (LAI) classed (0.5 LAI steps); stratified average data for the two plateaus

References 48

[1]	Bala G, Caldeira K, Wickett M, et al.2007. Combined climate and carbon-cycle effects of large-scale deforestation.Proceedings of the National Academy of Sciences, USA, 104(16): 6550-6555.
[2]	Bonan G B, Pollard D, Thompson S L.1992. Effects of Boreal Forest Vegetation on Global Climate.Nature, 359(6397): 716-718.
[3]	Brulebois E, Castel T, Richard Y, et al.2015. Hydrological response to an abrupt shift in surface air temperature over France in 1987/88.Journal of Hydrology, 531: 892-901.
[4]	Chen J, Wan S, Henebry G, et al.2013. Dryland East Asia: Land Dynamics amid Social and Climate Change. Higher Education Press. (in Chinese)
[5]	Choi M, Mu Q Z, Kim H, et al.2017. Ecosystem-dynamics link to hydrologic variations for different land-cover types.Terrestrial Atmospheric and Oceanic Sciences, 28(3): 437-462.
[6]	Cleugh H A, Leuning R, Mu Q Z, et al.2007. Regional evaporation estimates from flux tower and MODIS satellite data.Remote Sensing of Environment, 106(3): 285-304.
[7]	Davin E L, de Noblet-Ducoudre N.2010. Climatic Impact of Global-Scale Deforestation: Radiative versus Nonradiative Processes.Journal of Climate, 23(1): 97-112.
[8]	Enkhtur K, Pfeiffer M, Lkhagva A, et al.2017. Response of moths (Lepidoptera: Heterocera) to livestock grazing in Mongolian rangelands.Ecological Indicators, 72: 667-674.
[9]	Fatichi S, Ivanov V Y.2014. Interannual variability of evapotranspiration and vegetation productivity.Water Resources Research, 50(4): 3275-3294.
[10]	French A N, Hunsaker D J, Clarke T R.2012. Forecasting spatially distributed cotton evapotranspiration by assimilating remotely sensed and ground-based observations.Journal of Irrigation and Drainage Engineering-ASCE, 138(11): 984-992.
[11]	Friedl M A, McIver D K, Hodges J C F, et al.2002. Global land cover mapping from MODIS: algorithms and early results.Remote Sensing of Environment, 83(1): 287-302.
[12]	Garcia M, Fernandez N, Villagarcia L, et al.2014. Accuracy of the Temperature-Vegetation Dryness Index using MODIS under water-limited vs. energy-limited evapotranspiration conditions.Remote Sensing of Environment, 149: 100-117.
[13]	Gu S, Tang Y H, Cui X Y, et al.2008. Characterizing evapotranspiration over a meadow ecosystem on the Qinghai-Tibetan Plateau.Journal of Geophysical Research,113. Doi: 10.1029/2007JD009173.
[14]	IPCC.2014. Climate Change 2014. Synthesis Report Summary Chapter for Policymakers.
[15]	Jassal R S, Black T A, Spittlehouse D L, et al.2009. Evapotranspiration and water use efficiency in different-aged Pacific Northwest Douglas- fir stands.Agricultural and Forest Meteorology, 149(6): 1168-1178.
[16]	John R, Chen J Q, Lu N, et al.2009. Land cover/land use change in semi-arid Inner Mongolia: 1992-2004. Environmental Research Letters, 4(4). Doi: 10.1088/1748-9326/4/4/045010
[17]	John R, Chen J Q, Ou-Yang Z T, et al.2013. Vegetation response to extreme climate events on the Mongolian Plateau from 2000 to 2010. Environmental Research Letters, 8(3). Doi:10.1088/1748-9326/8/3/035033
[18]	Jung M, Reichstein M, Ciais P, et al.2010. Recent decline in the global land evapotranspiration trend due to limited moisture supply.Nature, 467(7318): 951-954.
[19]	Keeling R F, Piper S C, Heimann M.1996. Global and hemispheric CO2 sinks deduced from changes in atmospheric O-2 concentration.Nature, 381(6579): 218-221.
[20]	Krishnan P, Meyers T P, Scott R L, et al.2012. Energy exchange and evapotranspiration over two temperate semi-arid grasslands in North America.Agricultural and Forest Meteorology, 153: 31-44.
[21]	Krishnaswamy J, John R, Joseph S.2014. Consistent response of vegetation dynamics to recent climate change in tropical mountain regions.Global Change Biology, 20(1): 203-215.
[22]	Lee X, Goulden M L, Hollinger D Y, et al.2011. Observed increase in local cooling effect of deforestation at higher latitudes.Nature, 479(7373): 384-387.
[23]	Li G, Zhang F M, Jing Y S, et al.2017. Response of evapotranspiration to changes in land use and land cover and climate in China during 2001-2013.Science of the Total Environment, 596: 256-265.
[24]	Li Q Y, Xu L, Pan X B, et al.2016. Modeling phenological responses of Inner Mongolia grassland species to regional climate change. Environmental Research Letters , 11(1). Doi:10.1088/1748-9326/11/1/015002
[25]	Li Z Y, Wu W Z, Liu X H, et al.2017b. Land use/cover change and regional climate change in an arid grassland ecosystem of Inner Mongolia, China.Ecological Modelling, 353: 86-94.
[26]	Loranty M M, Berner L T, Goetz S J, et al.2014. Vegetation controls on northern high latitude snow-albedo feedback: observations and CMIP5 model simulations.Global Change Biology, 20(2), 594-606.
[27]	Lu N, Wilske B, Ni J, et al.2009. Climate change in Inner Mongolia from 1955 to 2005-trends at regional, biome and local scales. Environmental Research Letters, 4(4). Doi:10.1088/1748-9326/4/4/045006
[28]	Miao L J, Muller D, Cui X F, et al.2017. Changes in vegetation phenology on the Mongolian Plateau and their climatic determinants. Plos One, 12(12). Doi: 10.1371/journal.pone.0190313
[29]	Mu Q, Heinsch F A, Zhao M, et al.2007. Development of a global evapotranspiration algorithm based on MODIS and global meteorology data.Remote Sensing of Environment, 111(4): 519-536.
[30]	Myers-Smith I H, Elmendorf S C, Beck P S A, et al.2015. Climate sensitivity of shrub growth across the tundra biome.Nature Climate Change, 5(9): 887-892.
[31]	Myneni R B, Hall F G, Sellers P J, et al.1995. The Interpretation of Spectral Vegetation Indexes.IEEE Transactions on Geoscience and Remote Sensing, 33(2): 481-486.
[32]	Nemani R R, Keeling C D, Hashimoto,Het al.2003. Climate-driven increases in global terrestrial net primary production from 1982 to 1999.Science, 300(5626): 1560-1563.
[33]	Ni J.2004. Estimating net primary productivity of grasslands from field biomass measurements in temperate northern China.Plant Ecology, 174(2): 217-234.
[34]	Oki T, Kanae S.2006. Global hydrological cycles and world water resources.Science, 313(5790): 1068-1072.
[35]	Palmer A R, Weideman C, Finca A, et al.2015. Modelling annual evapotranspiration in a semi-arid, African savanna: functional convergence theory, MODIS LAI and the Penman-Monteith equation. African Journal of Range & Forage Science, 32(1): 33-39.
[36]	Peng S S, Piao S L, Ciais P, et al.2013. Asymmetric effects of daytime and night-time warming on Northern Hemisphere vegetation.Nature. DOI: 10.1038/nature12434
[37]	Pielke R A.2005. Land use and climate change.Science, 310(5754): 1625-1626.
[38]	Planque C, Carrer D, Roujean J L.2017. Analysis of MODIS albedo changes over steady woody covers in France during the period of 2001-2013.Remote Sensing of Environment, 191(15): 13-29.
[39]	Shen M G, Piao S L, Jeong S J, et al.2015. Evaporative cooling over the Tibetan Plateau induced by vegetation growth.Proceedings of the National Academy of Sciences, USA, 112(30): 9299-9304.
[40]	Tasumi M, Hirakawa K, Hasegawa N, et al.2014. Application of MODIS Land Products to Assessment of Land Degradation of Alpine Rangeland in Northern India with Limited Ground-Based Information.Remote Sensing, 6: 9260-9276.
[41]	Tian L, Zhang Y J, Zhu J T.2014. Decreased surface albedo driven by denser vegetation on the Tibetan Plateau. Environmental Research Letters, 9(10). Doi: 10.1088/1748-9326/9/10/104001
[42]	Tong X J, Zhang J S, Meng P, Li J, et al.2017. Environmental controls of evapotranspiration in a mixed plantation in North China.International Journal of Biometeorology, 61(2): 227-238.
[43]	Wang W G, Li J X, Yu Z B, et al.2018. Satellite retrieval of actual evapotranspiration in the Tibetan Plateau: Components partitioning, multidecadal trends and dominated factors identifying.Journal of Hydrology, 559: 471-485.
[44]	Wang Z S, Schaaf C B, Strahler A H, et al.2014. Evaluation of MODIS albedo product (MCD43A) over grassland, agriculture and forest surface types during dormant and snow-covered periods.Remote Sensing of Environment, 140: 60-77.
[45]	You Q G, Xue X, Peng F, et al.2017. Surface water and heat exchange comparison between alpine meadow and bare land in a permafrost region of the Tibetan Plateau.Agricultural and Forest Meteorology, 232: 48-65.
[46]	Zhang G L, Zhang Y J, Dong J W, et al.2013. Green-up dates in the Tibetan Plateau have continuously advanced from 1982 to 2011. Proceedings of the National Academy of Sciences, USA, 110(11): 4309-4314.
[47]	Zhang R Z, Yang Q Y.1982.Physical Geography of Xizang. Beijing: Science Press .(in Chinese)
[48]	Zhang Y, Kadota T, Ohata T, et al.2007. Environmental controls on evapotranspiration from sparse grassland in Mongolia.Hydrological Processes, 21: 2016-2027.