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Role
of nurse shrubs for restoration planting of two conifers in southeast of Mu
Us Sandland, China
Li Tian1,2
and Xiaoan Wang1*
1College of Life
Sciences, Shaanxi Normal University, Xi'an, Shaanxi-710 062, China
2College of Life
Sciences, Yulin University, Yulin, Shaanxi-719 000, China
*Corresponding
Author E-mail: wangxiaoana@sina.com
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Publication
Data
Paper received:
29 September 2014
Revised received:
26 November 2014
Accepted:
03 December 2014
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Abstract
Two-year-old
pine seedlings, Pinus tabulaeformis and Pinus sylvestris were
planted under the canopies of three shrub species and in open areas to test
for facilitation during seedling establishment in southeast of Mu Us Sandland
in northern part of Shaanxi, China. Pine seedlings establishment were
assessed three times within three consecutive growing seasons. Height, area
and volume of shrubs were measured. Microclimate conditions (light intensity,
air temperature and soil temperature and moisture) were recorded in four microhabitats.
Near surface light intensity, air temperature and soil temperature were lower
under shrubs, which led to higher soil moisture and pine seedlings under the
canopy of shrub species. Pine seedlings survival was remarkably higher when
planted under the canopy of shrub species (65.7% for P. tabulaeformis and
60.6% for P. sylvestris) as compared with open areas (22.4% for P.
tabulaeformis and 38% for P. sylvestris). P. tabulaeformis
with shade-tolerance trait expressed high survival of seedlings as compared
to that of P. sylvestris seedlings under the canopy of shrub species
(Tukey test, P<0.05). Leguminous shrub (Caragana korshinskii and Amorpha
fruticosa) showed continuously facilitation during moderate drought
stress (summer 2012, 2013 and 2014), but dense and small shrub (Caragana
korshinskii) reduced the establishment of seedlings possibly for light
competition. Salix cheilophila showed a facilitation effect in growing
seasons, but the effect of allelopathy led to high mortality of seedlings
under their canopy. In addition, two pine growths were not inhibited when
planted under three shrubs. In conclusions, nurse-shrub facilitation can be
used as an effective restoration strategy in this sandland. However, use of
shrubs as nurse plants depends on their canopy structure and ecological
impacts; the selection of target species depends on their shade tolerance
traits. ????
Key
words
Facilitation,
Mu Us Sandland, Nurse shrub, Pine, Restoration
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? 2015 Triveni Enterprises. All rights reserved. No part of the Journal can
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conclusions enforced or derived, rest completely with the author(s).
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