title: Life span and structure of ephemeral root modules of different functional groups from a desert system.
abstract: The terminal branch orders of plant root systems have been proposed as short-lived 'ephemeral' modules specialized for resource absorption. The occurrence of ephemeral root modules has so far only been reported for a temperate tree species and it is unclear if the concept also applies to other woody (shrub, tree) and herb species. Fine roots of 12 perennial dicotyledonous herb, shrub and tree species were monitored for two growing seasons using a branch-order classification, sequential sampling and rhizotrons in the Taklamakan desert. Two root modules existed in all three plant functional groups. Among the first five branch orders, the first two (perennial herbs, shrubs) or three (trees) root orders were ephemeral and had a primary anatomical structure, high nitrogen (N) concentrations, high respiration rates and very short life spans of 1-4 months, whereas the last two branch orders in all functional groups were perennial, with thicker diameters, no or collapsed cortex, distinct secondary growth, low N concentrations, low respiration rates, but much longer life spans. Ephemeral, short-lived root modules and long-lived, persistent root modules seem to be a general feature across many plant functional groups and could represent a basic root system design.
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China.|Cele National Station of Observation and Research for Desert Grassland Ecosystem in Xinjiang, Cele, 848300, Xinjiang, China.
authors: Bo
authors: B
authors: Liu
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China.|Cele National Station of Observation and Research for Desert Grassland Ecosystem in Xinjiang, Cele, 848300, Xinjiang, China.
authors: Junxia
authors: J
authors: He
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China.|Cele National Station of Observation and Research for Desert Grassland Ecosystem in Xinjiang, Cele, 848300, Xinjiang, China.|Key Laboratory of Biogeography and Bioresource in Arid Land, Chinese Academy of Sciences, Urumqi, 830011, China.
authors: Fanjiang
authors: F
authors: Zeng
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China.|Cele National Station of Observation and Research for Desert Grassland Ecosystem in Xinjiang, Cele, 848300, Xinjiang, China.
authors: Jiaqiang
authors: J
authors: Lei
authors: School of Ecosystem and Forest Sciences, University of Melbourne, 500 Yarra Boulevard, 3121, Richmond, Vic, Australia.
authors: Stefan K
authors: SK
authors: Arndt
mesh_terms: D002681:China; D003889:Desert Climate; D017753:Ecosystem; D019684:Magnoliopsida / Q000033:anatomy & histology / Q000502:physiology; D031625:Morus / Q000033:anatomy & histology / Q000502:physiology; D009584:Nitrogen / Q000378:metabolism; D018517:Plant Roots / Q000033:anatomy & histology* / Q000502:physiology*; D010944:Plants / Q000033:anatomy & histology*; D032107:Populus / Q000033:anatomy & histology / Q000502:physiology; D013997:Time Factors; D014197:Trees
chemical_list: D009584:Nitrogen
keywords: anatomical traits; ephemeral root module; fine roots; functional groups; life span; modified rhizotron; nitrogen concentration; respiration