Variations of root traits in three Xizang grassland communities along a precipitation gradient

doi:10.17521/cjpe.2018.0140

Abstract

Abstract:

Aims Root functional traits and their variations mediate coexistence and adaptive strategy of plant species. Yet, strong environmental constraints may induce convergence of root traits among different plant species. To study the variations of root traits and clarify the diverse adaptive strategies across plant species, we sampled three alpine grasslands along a precipitation gradient in the Xizang Plateau.
Methods In three grassland communities along a precipitation gradient: Nagqu, Baingoin and Nyima from east to west of Xizang Plateau, we collected 22 coexisting plant species and measured three key root traits: 1st-order root diameter, 1st-order lateral root length and root branch intensity.
Important findings The main results showed that: (1) the root of plants in the alpine grassland was generally thin, and the interspecific variation was also small (22.76%); (2) the root diameter of 86% plant species was in the range from 0.073 mm to 0.094 mm. Compared with the thick-root species, thin-root species had a higher root branching intensity, but shorter lateral root length. In addition, at community-level, plants mainly increased root diameter and lateral root length, but reduced root branching intensity to adapt to the decreasing precipitation; while at species-level, the plant species exhibited diverse adaptive strategies along the precipitation gradient.

http://jtp.cnki.net/bilingual/detail/html/ZWSB201811004

Key words: trait variation, adaptive strategy, root branching, root diameter, root length, alpine grassland

ZHOU Wei, LI Hong-Bo, ZENG Hui. Variations of root traits in three Xizang grassland communities along a precipitation gradient[J]. Chin J Plant Ecol, 2018, 42(11): 1094-1102.

Add to citation manager EndNote|Ris|BibTeX

URL: https://www.plant-ecology.com/EN/10.17521/cjpe.2018.0140

https://www.plant-ecology.com/EN/Y2018/V42/I11/1094

Figures/Tables 7

Table 1 Basic information of the sampling sites of root in Xizang alpine grassland communities

地点 Site	经纬度 Latitude and longitude	年平均气温 Mean annual temperature (℃)	年降水量 Mean annual precipitation (mm)	海拔 Elevation (m)	土壤氮含量 Soil N (%)	土壤碳含量 Soil C (%)	土壤碳氮比 Soil C:N
那曲 Nagqu	31.65° N, 92.02° E	-2.2	445	4 600	0.193	1.965	22.97
班戈 Baingoin	31.43° N, 90.03° E	-1.2	329	4 700	0.117	1.081	13.93
尼玛 Nyima	32.08° N, 86.90° E	-3.1	286	4 780	0.115	2.062	18.24

Fig. 1 Variations of phylogeny and traits among the 22 plant species in the alpine grassland.

Table 2 Summary of the three root traits for 22 species in Xizang alpine grassland

根属性 Root trait	最小值 Min.	最大值 Max.	平均值 Mean	变异系数 Coefficient of variation (%)
一级根直径 1st-order root diameter (mm)	0.073	0.142	0.088	22.76
一级根长度 1st-order root length (mm)	0.335	5.239	1.541	80.19
根系分支强度 Root branching intensity (No.cm^-1)	1.119	12.041	4.439	61.05

Table 3 Pearson correlations with (top right) and without (bottom left) phylogenetically independent contrasts for root traits across 22 species in Xizang alpine grassland

根属性 Root trait	一级根直径 1st-order root diameter	分支强度 Root branching intensity	一级根长度 1st-order root length
一级根直径 1st-order root diameter		-0.008^ns	0.672^**
根系分支强度 Root branching intensity	-0.432^*		-0.139^ns
一级根长度 1st-order root length	0.728^**	-0.573^**

Fig. 2 Community-weighted root traits of the three grasslands along the precipitation gradient in Xizang alpine grassland.

Fig. 3 Root trait mean values of seven regionally common species (appearing in two or three sites at the same time) at three grassland sites (mean + SE) in Xizang alpine grassland. Ad, Artemisia demissa; Ts, Trisetum spicatum; Lp, Leontopodium pusillum; Sp, Stipa purpurea; Pb, Potentilla bifurca; Om, Oxytropis microphylla; Hs, Heteropappus semiprostratus.

Fig. 4 The average percentage of root traits of seven regionally common species (appearing in two or three sites at the same time) to water stress at three grassland sites in Xizang alpine grassland. Ad, Artemisia demissa; Ts, Trisetum spicatum; Lp, Leontopodium pusillum; Sp, Stipa purpurea; Pb, Potentilla bifurca; Om, Oxytropis microphylla; Hs, Heteropappus semiprostratus.

References 41

[1]	Ackerly DD, Cornwell WK ( 2007). A trait-based approach to community assembly: Partitioning of species trait values into within-and among-community components. Ecology Letters, 10, 135-145. DOI URL PMID
[2]	Albert CH, Grassein F, Schurr FM, Vieilledent G, Violle C ( 2011). When and how should intraspecific variability be considered in trait-based plant ecology? Perspectives in Plant Ecology Evolution & Systematics, 13, 217-225. DOI URL
[3]	Albert CH, Thuiller W, Yoccoz NG, Douzet R, Aubert S, Lavorel S ( 2010). A multi-trait approach reveals the structure and the relative importance of intraspecific vs. interspecific variability in plant traits. Functional Ecology, 24, 1192-1201. DOI URL
[4]	Bernston GM ( 1997). Topological scaling and plant root system architecture: Developmental and functional hierarchies. New Phytologist, 135, 621-634. DOI URL
[5]	Bystrova EI, Zhukovskaya NV, Ivanov VB ( 2018). Dependence of root cell growth and division on root diameter. Russian Journal of Developmental Biology, 49, 79-86. DOI URL
[6]	Chen J, Luo Y, Xia J, Cao J ( 2016). Differential responses of ecosystem respiration components to experimental warming in a meadow grassland on the Tibetan Plateau. Agricultural & Forest Meteorology, 220, 21-29. DOI URL
[7]	Chen W, Zeng H, Eissenstat DM, Guo D ( 2013). Variation of first-order root traits across climatic gradients and evolutionary trends in geological time. Global Ecology & Biogeography, 22, 846-856. DOI URL
[8]	Cornwell WK, Ackerly DD ( 2009). Community assembly and shifts in plant trait distributions across an environmental gradient in coastal California. Ecological Monographs, 79, 109-126. DOI URL
[9]	Díaz S, Kattge J, Cornelissen JH, Wright IJ, Lavorel S, Dray S, Reu B, Kleyer M, Wirth C, Prentice IC, Garnier E, Bönisch G, Westoby M, Poorter H, Reich PB, Moles AT, Dickie J, Gillison AN, Zanne AE, Chave J, Wright SJ, Sheremet'ev SN, Jactel H, Baraloto C, Cerabolini B, Pierce S, Shipley B, Kirkup D, Casanoves F, Joswig JS, Günther A, Falczuk V, Rüger N, Mahecha MD, Gorné LD ( 2016). The global spectrum of plant form and function. Nature, 529, 167-171. DOI URL PMID
[10]	Dwyer JM, Laughlin DC ( 2017). Constraints on trait combinations explain climatic drivers of biodiversity: The importance of trait covariance in community assembly. Ecology Letters, 20, 872-882. DOI URL PMID
[11]	Eissenstat DM ( 1991). On the relationship between specific root length and the rate of root proliferation: A field study using citrus rootstocks. New Phytologist, 118, 63-68. DOI URL
[12]	Eissenstat DM, Kucharski JM, Zadworny M, Adams TS, Koide RT ( 2015). Linking root traits to nutrient foraging in arbuscular mycorrhizal trees in a temperate forest. New Phytologist, 208, 114-124. DOI URL PMID
[13]	Fajardo A, Piper FI ( 2011). Intraspecific trait variation and covariation in a widespread tree species (Nothofagus pumilio) in southern Chile. New Phytologist, 189, 259. DOI URL PMID
[14]	Fitter AH ( 1987). An architectural approach to the comparative ecology of plant root systems. New Phytologist, 106, 61-77. DOI URL
[15]	Jiang YB, Fan M, Zhang YJ ( 2017). Effect of short-term warming on plant community features of alpine meadow in Northern Tibet. Chinese Journal of Ecology, 36, 616-622. DOI URL
	[ 姜炎彬, 范苗, 张扬建 ( 2017). 短期增温对藏北高寒草甸植物群落特征的影响. 生态学杂志, 36, 616-622.] DOI URL
[16]	Jung V, Muller S ( 2010). Intraspecific variability and trait- based community assembly. Journal of Ecology, 98, 1134-1140. DOI URL
[17]	Kembel SW, Cowan PD, Helmus MR, Cornwell WK, Morlon H, Ackerly DD, Blomberg SP, Webb CO ( 2010). Picante: R tools for integrating phylogenies and ecology. Bioinformatics, 26, 1463-1464. DOI URL PMID
[18]	Kichenin E, Freschet GT ( 2013). Contrasting effects of plant inter- and intraspecific variation on community-level trait measures along an environmental gradient. Functional Ecology, 27, 1254-1261. DOI URL
[19]	Kong D, Ma C, Zhang Q, Li L, Chen X, Zeng H, Guo D ( 2014). Leading dimensions in absorptive root trait variation across 96 subtropical forest species. New Phytologist, 203, 863-872. DOI URL PMID
[20]	Kraft NJB, Godoy O, Levine JM ( 2015). Plant functional traits and the multidimensional nature of species coexistence. Proceedings of the National Academy of Sciences of the United States of America, 112, 797-802. DOI URL PMID
[21]	Kunstler G, Falster D, Coomes DA, Hui F, Kooyman RM, Laughlin DC, Poorter L, Vanderwel M, Vieilledent G, Wright SJ, Aiba M, Baraloto C, Caspersen J, Cornelissen JH, Gourlet-Fleury S, Hanewinkel M, Herault B, Kattge J, Kurokawa H, Onoda Y, Peñuelas J, Poorter H, Uriarte M, Richardson S, Ruiz-Benito P, Sun IF, Ståhl G, Swenson NG, Thompson J, Westerlund B, Wirth C, Zavala MA, Zeng H, Zimmerman JK, Zimmermann NE, Westoby M ( 2011). Plant functional traits have globally consistent effects on competition. Nature, 529, 204-207. DOI URL PMID
[22]	Kunstler G, Lavergne S, Courbaud B, Thuiller W, Vieilledent G, Zimmermann NE, Kattge J, Coomes DA ( 2012). Competitive interactions between forest trees are driven by species’ trait hierarchy, not phylogenetic or functional similarity: Implications for forest community assembly. Ecology Letters, 15, 831-840. DOI URL PMID
[23]	Laughlin DC, Joshi C, van Bodegom PM, Bastow ZA, Fulé PZ ( 2012). A predictive model of community assembly that incorporates intraspecific trait variation. Ecology Letters, 15, 1291-1299. DOI URL PMID
[24]	Laughlin DC, Messier J ( 2015). Fitness of multidimensional phenotypes in dynamic adaptive landscapes. Trends in Ecology & Evolution, 30, 487-496. DOI URL PMID
[25]	Li H, Liu B, Mccormack ML, Ma Z, Guo D ( 2017). Diverse belowground resource strategies underlie plant species coexistence and spatial distribution in three grasslands along a precipitation gradient. New Phytologist, 216, 1140-1150. DOI URL PMID
[26]	Liu B, Li H, Zhu B, Koide RT, Eissenstat DM, Guo D ( 2015). Complementarity in nutrient foraging strategies of absorptive fine roots and arbuscular mycorrhizal fungi across 14 coexisting subtropical tree species. New Phytologist, 208, 125-136. DOI URL PMID
[27]	Lynch JP ( 2013). Steep, cheap and deep: An ideotype to optimize water and N acquisition by maize root systems. Annals of Botany, 112, 347. DOI URL
[28]	McCormack ML, Adams TS, Smithwick EA, Eissenstat DM ( 2012). Predicting fine root lifespan from plant functional traits in temperate trees. New Phytologist, 195, 823-831. DOI URL PMID
[29]	Messier J, Mcgill BJ, Lechowicz MJ ( 2010). How do traits vary across ecological scales? A case for trait-based ecology. Ecology Letters, 13, 838-848. DOI URL PMID
[30]	Muscarella R, Uriarte M ( 2016). Do community-weighted mean functional traits reflect optimal strategies? Proceedings of the Royal Society B: Biological, 283, 20152434. DOI: 10.?1098/rspb.2015.2434. DOI URL PMID
[31]	Nosil P, Harmon LJ, Seehausen O ( 2009). Ecological explanations for (incomplete) speciation. Trends in Ecology & Evolution, 24, 145-156. DOI URL PMID
[32]	Pérez-Ramos IM, Roumet C, Cruz P, Blanchard A, Autran P, Garnier E ( 2012). Evidence for a “plant community economics spectrum” driven by nutrient and water limitations in a mediterranean rangeland of southern France. Journal of Ecology, 100, 1315-1327. DOI URL
[33]	Pregitzer KS, Deforest JL, Burton AJ, Allen MF, Ruess RW, Hendrick RL ( 2002). Fine root architecture of nine North American trees. Ecological Monographs, 72, 293-309. DOI URL
[34]	Reich PB ( 2014). The world-wide “fast-slow” plant economics spectrum: A traits manifesto. Journal of Ecology, 102, 275-301. DOI URL
[35]	Umaña MN, Zhang C, Cao M, Lin L, Swenson NG ( 2015). Commonness, rarity, and intraspecific variation in traits and performance in tropical tree seedlings. Ecology Letters, 18, 1329. DOI URL PMID
[36]	Valladares F, Bastias CC, Godoy O, Granda E, Escudero A ( 2015). Species coexistence in a changing world. Frontiers in Plant Science, 6, 866. DOI URL PMID
[37]	Valverde-Barrantes OJ, Freschet GT, Roumet C, Blackwood CB ( 2017). A worldview of root traits: The influence of ancestry, growth form, climate and mycorrhizal association on the functional trait variation of fine-root tissues in seed plants. New Phytologist, 215, 1562-1573. DOI URL
[38]	Violle C, Enquist BJ, Mcgill BJ, Jiang L, Albert CH, Hulshof C, Jung V, Messier J ( 2012). The return of the variance: Intraspecific variability in community ecology. Trends in Ecology & Evolution, 27, 244-252.
[39]	Wu JS, Li XJ, Shen ZX, Zhang XZ, Shi PL, Yu CQ, Wang JS, Zhou YT ( 2012). Species diversity distribution pattern of alpine grasslands communities along a precipitation gradient across Northern Tibetan Plateau. Acta Prataculturae Sinica, 21, 17-25. DOI URL
	[ 武建双, 李晓佳, 沈振西, 张宪洲, 石培礼, 余成群, 王景升, 周宇庭 ( 2012). 藏北高寒草地样带物种多样性沿降水梯度的分布格局. 草业学报, 21, 17-25.] DOI URL
[40]	Zhan A, Schneider H, Lynch JP ( 2015). Reduced lateral root branching density improves drought tolerance in maize. Plant Physiology, 168, 1603-1615. DOI URL PMID
[41]	Zhu GL, Li J, Wei XH, He NP ( 2017). Longitudinal patterns of productivity and plant diversity in Tibetan alpine grasslands. Journal of Natural Resources, 32, 210-222.
	[ 朱桂丽, 李杰, 魏学红, 何念鹏 ( 2017). 青藏高寒草地植被生产力与生物多样性的经度格局. 自然资源学报, 32, 210-222.]