Analysis of Canopy Structure of Plant Communities in Mongolian Grasslands

蒙古草原植物群落冠层结构分析

基本信息

批准号：
09041142
负责人：
HIROSE Tadaki
金额：
$ 4.1万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

We studied the nitrogen use efficiency (NUE) and water use efficiency (WUE) of species growing in a humidity gradient in Mongolian grasslands to examine if there is a trade-off between the two efficiencies. Total 131 species were collected from 7 sites. WUE was evaluated by the compositional deviation of ィイD113ィエD1C(δィイD113ィエD1C). NUE was evaluated as a reciprocal of leaf nitrogen concentration (LNC). Species in drier habitats tended to have higher WUE, but there was no such trend in NUE. No trade-off was found between WUE and NUE across species distributed in different climates. However, when the values for WUE and NUE were standardized against their means for species found more than three sites, WUE increased and NUE decreased with increasing aridity, indicating the trade-off between NUE and WUE within species. Only two (Cleistogenes squarrosa and Salsola passerina) out of 131 species were found to have the C4 metabolism.Effects of climate and grazing intensities on the structure of grassland vegetation were studied. We have established three exclosures in different climates : Partizan (mesic steppe), Tumentsogt (typical steppe) and Bayan-Unjuul (dry steppe). First year vegetation survey gave 45 species (including 7 grasses) in Partizan, 46 species (8 grasses) in Tumentsogt and 18 species (4 grasses) in Bayan-Unjuul. Aboveground biomass was 122 g dw mィイD2-2ィエD2 at Parizan, 122 at Tumentsogt, and 53 at Bayan-Unjuul. Difference between exclosure and grazing plots was small, probably because of the short time since establishment of the exclosure and an unusually dry summer in 1999.

我们研究了蒙古草原湿度梯度中生长的物种的氮利用效率（NUE）和用水效率（WUE），以检查两种效率之间是否在两种效率之间进行了权衡。从7个地点收集了总共131种。 WUE通过ΔID113D1C（ΔID113 D1C）的复合差异评估。 NUE被评估为叶氮浓度（LNC）的倒数。驾驶员栖息地中的物种往往具有较高的WUE，但NUE没有这种趋势。在不同气候下分布的物种之间，WUE和NUE之间没有发现权衡。但是，当Wue和Nue的价值与发现三个以上地点的物种的平均水平进行标准化时，Wue增加了，随着干旱的增加，NUE降低了，这表明物种内NUE和WUE之间的权衡。在131种中，只有两个（克氏菌基因生成虫和莎莎酱）具有C4代谢。对草原植被结构的气候和磨碎强度的效果进行了研究。我们已经在不同的气候中建立了三个包括：Partizan（Mesic草原），Tumentsogt（典型的草原）和Bayan-Unjuul（干草原）。第一年的植被调查给了45种（包括7种草），在tomentizan中提供了46种（8种草），在Bayan-Unjuul中提供了18种（4种草（4种草）（4种草）。地上生物量在帕里山（Parizan）为122 g DW MII D2-2，在Tumentogt为122，在Bayan-Unjuul为53。排除和光栅地块之间的差异很小，这可能是因为自1999年建立排除术和异常干燥的夏天以来的时间很短。