Root System Ecology of Shrubs in Qilian Mountains Alpine Rhododendron Shrubland

University of Kentucky UKnowledge

XXI International Grassland Congress / VIII International Grassland Congress Proceedings International Rangeland Congress

Wenxia Cao Gansu Agricultural University, China

Degang Zhang Gansu Agriculutral University, China

Fuzeng Hong Gansu Agriculutral University, China

Follow this and additional works at: https://uknowledge.uky.edu/igc

Part of the Plant Sciences Commons, and the Soil Science Commons This document is available at https://uknowledge.uky.edu/igc/21/1-2/48 The XXI International Grassland Congress / VIII International Rangeland Congress took place in Hohhot, China from June 29 through July 5, 2008. Proceedings edited by Organizing Committee of 2008 IGC/IRC Conference Published by Guangdong People's Publishing House

This Event is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in International Grassland Congress Proceedings by an authorized administrator of UKnowledge. For more information, please contact [email protected]. Multifunctional Grasslands in a Changing World Volume Ⅰ 瞯 97 瞯 ]

Root system ecology of shrubs in Qilian Mountains alpine rhododendron shrubland

Cao Wenxia , Zhang Degang , Hong Fuzeng Grassland Science College , Gansu A gricultural University , L anz hou 730070 , China . E‐mail :caowenxia＠ sina .com

Key words : １６ rhododendron root system ecology , shrub species , alpine shrubland , disturbance , climate warming ,Qilian mountains Introduction ‐ The Qilian Mountains National Nature ReserveRhododendron located in‐ the northeastern edge of Qinghai３０００ Tibet Plateau is the key areas for global climatic change research . The alpine shrubland survived above , ‐ m in protection area has been attracting the attention for its important ecological services function , and is also the summer pasture for rare white yak and other herbivores . Under global warming background , what or how the impact caused on the shrubland ecosystem by increasing human disturbance are the main reasons of this study . From root system ecology to understand belowground ecological characteristics and response of ecological process to disturbance could provide belowground ecological data and theoretical support for scientific utilization and conservation１６ , however , alpine shrub root systemRhododendron studies were seldom found . The root system architecture and spatial distribution of shrub species existing in alpine shrubland were studied , and the relationship with environment were discussed . Methods ５ The study area was the north slope of the Eastern Qilian Mountains ,about km from research station of GSAU .The Rhododendron Rhododendron thymi f olium ( R .t ) ,R. shrub species existing in alpine shrubland were investigated including cap itatum(R .c ) ,R . anthopogonoides ( R . a ) ,R. p rzew alskii ( R. p ) ,Salix oritrepha ( S .o ) ,S . rehderiana ( S . r ) ,S. sclerophylla( S .s) ,Lonicera hispida( L .h) ,L . rup icola ( L .r ) ,L. f erdinadii ( L. f ) ,Potentilla f ruticosa ( P. f ) ,Sp riaea alpina( Sp .a) ,Caragana j ubata(C.j ) ,A retous ruber (A .r) ,Rubus irritans (R .i) and H ip pophae tibetica( H .t) . Coarse root length and distribution were studied by using traditional skeleton‐ method to expose root１９９５ systems ,and２００１ fine root length and distribution were studied by soil core sampling method and wet sieving method( Mou P . , ; Robert , ) . Results ０‐３０１ (R .t ; R .c ; RThe .p ; S root .o) system of shrubs spread mainly(S .r;S.s;R.a;L in the cm .f soil layer (Figure ) . The shallow root dominant species‐ Sp .a ; Pand .f ;C. subdominantj species ) form the constructiveL . h synusia; A . r of the community ; deep rooted shrubs ( ) are only companion species form the middle synusia ; compose the low synusia ,other species are rare species in community .

0 R.t R.cR.aRp So Sr Ssl.h L.r U PfSpaC.j A.r

10 20 'E' 30 140 15. {l 50 g 60 70 oJ Vertical distribution depth 80 ~ dominant soil layer of total fine root length 90 □

Figure 1 Overlap ping and sep aration o f niche o f di f f erent shrub roots in soil layer .

Discussion １６ By using niche overlapping and separating theory , the role of shrubs species in the community and the relationship with environment can be explained . The dominant species and‐ subdominant species adapt to the alpine freezing and humid environment with shallow and dense root distribution , but deep rooted shrubs‐ only can survived occasionally in community‐ . Global climate摧 warming and human activity disturbance may lead that the deep root style shrubs replace the current shallow roots type s constructive species in succession . The hypothesis is consistent with the status of serious damaged Rhododendron shrubland and transitional zone . References et al . , １９９５ MouP.R.H.Jones R.J. . Spatial distribution of roots in sweetgum and loblolly pine monocultures and ( ) Functional Ecology ９６８９‐６９９ relations with aboveground biomass and soil nutrients . , , . et al . , ２００１ Journal o f A rid Env ironments , ４９２２１‐ Robert２６３ P . Gibbens ( ) . Root systems of some Chihuahuan Desert plants . , .

Grasslands/Rangelands Resources and Ecology ——— Ecology of Grasslands/Rangelands