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Effects of climate and nomadic activities on the development of grassland vegetation in Mongolia

气候和游牧活动对蒙古草原植被发育的影响

基本信息

批准号：
12575003
负责人：
HIROSE Tadaki
金额：
$ 6.59万
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：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12575003/
关键词：
Mongolia Grassland Vegetation Climate Nomadism

项目摘要

Mongolian grasslands have been under strong influence of the traditional nomadic activities. We studied how the structure and function of grassland vegetation are influenced by the climate and nomadic activities. In June 1999 we established exclosures with a dimension of100 x 100 m to exclude grazing effects of livestock in mesic (Partizan), typical(Tumentsogt) and dry(Bayan-Unjuul) steppe zone. Inside and outside of the exclosure, ten permanent quadrats were set at each study site. We described species structure of vegetation in the permanent quadrats and harvested plant samples from four 0.5 x 0.5 m quadrates inside and outside of the exclosure in summer (July - August) of 1 999 through 2002. The number of species appeared in an area of 1 m^2 in 1999 was 45 at Partizan, 46 at Tumentsogt and 18 at Bayan-Unjuul. There was no significant difference in the species composition and aboveground plant biomass between inside and outside of the exclosure in 1999. Species-Area curves indicated that species number nearly saturated at 2 m^2 both at Tumentsogt and Bayan-Unjuul, while it was still increasing at Partizan reflecting its higher species diversity. Although the species composition in 2002 was not different from that in 1999, aboveground biomass and the leaf area index were higher in the exclosure than the outside grazing zone. Reduction in soil evaporation due to litter accumulation as well as exclusion of livestock grazing were probably responsible for the higher aboveground growth in the exclosure. Species composition changed with climate. Proportion of gramineae in the aboveground biomass increased and overall species diversity decreased with Bowing of precipitation. There were year-to-year variations in biomass and species composition probably owing to different summer precipitation.

蒙古草原深受传统游牧活动的影响。我们研究了气候和游牧活动如何影响草原植被的结构和功能。 1999 年 6 月，我们建立了尺寸为 100 x 100 m 的围栏，以排除中等草原（Partizan）、典型草原（Tumentsogt）和干旱草原（Bayan-Unjuul）地区牲畜放牧的影响。在围墙内外，每个研究地点设置了十个永久样方。我们描述了永久样方植被的物种结构，并从 1 999 年至 2002 年夏季（7 月至 8 月）从保护区内外的 4 个 0.5 x 0.5 m 方方收获的植物样本。 1999 年 1 m^2 面积内出现的物种数量为 Partizan 45 个、Tumentsogt 46 个和 Bayan-Unjuul 18 个。 1999年，保护区内外的物种组成和地上植物生物量没有显着差异。物种面积曲线表明，图门索格特和巴彦温朱尔的物种数量接近饱和，达到2 m^2，而游击区的物种数量仍在增加，反映了其较高的物种多样性。虽然2002年的物种组成与1999年没有什么不同，但围垦区的地上生物量和叶面积指数高于外部放牧区。由于凋落物堆积而导致的土壤蒸发减少以及牲畜放牧的排除可能是围场中地上生长较高的原因。物种组成随气候而变化。随着降水的减少，禾本科植物在地上生物量中的比例增加，总体物种多样性减少。生物量和物种组成存在逐年变化，可能是由于夏季降水不同所致。