Experimental sand burial affects seedling survivorship, morphological traits, and biomass allocation of <i>Ulmus pumila</i> var. <i>sabulosa</i> in the Horqin Sandy Land, China
As a native tree species, <i>Ulmus pumila</i> var. <i>sabulosa</i> (sandy elm) is widely distributed in the Horqin Sandy Land, China. However, seedlings of this species have to withstand various depths of sand burial after emergence because of increasing soil degradation, whi...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-07-01
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| Series: | Solid Earth |
| Online Access: | http://www.solid-earth.net/7/1085/2016/se-7-1085-2016.pdf |
| Summary: | As a native tree species, <i>Ulmus pumila</i> var. <i>sabulosa</i> (sandy elm) is widely distributed in
the Horqin Sandy Land, China. However, seedlings of this species have to
withstand various depths of sand burial after emergence because of
increasing soil degradation, which is mainly caused by overgrazing, climate
change, and wind erosion. An experiment was conducted to evaluate the
changes in its survivorship, morphological traits, and biomass allocation
when seedlings were buried at different burial depths: unburied controls and
seedlings buried vertically up to 33, 67, 100, or 133 % of their initial
mean seedling height. The results showed that partial sand burial treatments
(i.e., less than 67 % burial) did not reduce seedling survivorship, which
still reached 100 %. However, seedling mortality increased when sand
burial was equal to or greater than 100 %. In comparison with the control
treatment, seedling height and stem diameter increased at least by 6 and
14 % with partial burial, respectively. In the meantime, seedling taproot
length, total biomass, and relative mass growth rates were at least enhanced
by 10, 15.6, and 27.6 %, respectively, with the partial sand
burial treatment. Furthermore, sand burial decreased total leaf area and
changed biomass allocation in seedlings, partitioning more biomass to
aboveground organs (e.g., leaves) and less to belowground parts (roots).
Complete sand burial after seedling emergence inhibited its re-emergence and
growth, even leading to death. Our findings indicated that seedlings of
sandy elm showed some resistance to partial sand burial and were adapted to
sandy environments from an evolutionary perspective. The negative effect of
excessive sand burial after seedling emergence might help in understanding
failures in recruitments of sparse elm in the study region. |
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| ISSN: | 1869-9510 1869-9529 |