Effect of simulated grazing on sediment trapping by single plants: A wind-tunnel experiment with two grassland species in Mongolia
Effect of simulated grazing on sediment trapping by single plants: A wind-tunnel experiment with two grassland species in Mongolia
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模拟放牧对单一植物截留沉积物的影响：蒙古两种草地的风洞实验
DOI：
10.1016/j.catena.2021.105262
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发表时间：
2021
期刊：
影响因子：
6.2
通讯作者：
R.
中科院分区：
文献类型：
--
作者：
Kinugasa;T.;Sagayama;T.;Gantsetseg;B.;Liu;J. and Kimura;R.
植被覆盖抑制干旱地区的沙尘暴。畜牧业是干旱地区的主要产业，虽然牲畜吃草，但它们的放牧对草捕获沉积物的能力的影响还不清楚。本研究在风洞实验中量化了植物修剪（一种模拟动物放牧的方式）对单一植物沉积物截留的影响。本研究以克氏针茅和冰草两种牧草为研究对象，这两种牧草原产于蒙古草原，对牲畜来说非常可口。这两个物种生长到大约30厘米的高度，然后将单株植物放置在风洞中。在风速为8 m s−1的风吹5分钟之前和期间，拍摄了工厂的正面区域。试验结束后，测量了植物后面积累的沉积物。然后将植物的顶部5cm剪掉，并使植物经受另一次风吹试验。重复这个实验序列，直到植物的地上部分被完全移除。虽然弯曲的S。krylovii在风中是明显的，弯曲停止时，植物体的上部已被剪掉。修剪减少了锋面面积，但沉积物积累量几乎没有减少，直到所有的地上生物量已被删除。这些结果表明，沉积物的捕获由一个单一的植物可能是由于由地上植物体的下部所产生的遮蔽效果，灵活的植物体的上部显然对沉积物的捕获贡献很小。因此，当植物是孤立的或非常稀疏的分散时，通过放牧失去草体的上半部分对沉积物截留的影响很小。
Vegetative cover suppresses dust storms in arid regions. Rearing livestock is a major industry in arid regions, and although livestock consume grass, the effect of their grazing on the ability of grass to trap sediments is not well understood. This study quantified the effect of plant clipping, a mimic of animal grazing, on sediment trapping by single plants in a wind-tunnel experiment. The study focused on two grass species,Stipa kryloviiandAgropyron cristatum, which are native to the Mongolian steppe and are highly palatable for livestock. The two species were grown to a height of approximately 30 cm, and then single plants were placed in a wind tunnel. The frontal area of the plant was photographed before and during 5 min of wind blowing at a velocity of 8 m s−1. The sediment that accumulated behind the plant was measured after the trial. The top 5 cm of the plant was then clipped away, and the plant was subjected to another wind-blowing trial. This experimental sequence was repeated until the above-ground part of the plant had been entirely removed. Although bending ofS. kryloviiin the wind was clearly apparent, bending ceased when the upper part of the plant body had been clipped away. Clipping reduced the frontal area, but there was little decrease in sediment accumulation until all of the above-ground biomass had been removed. These results indicated that sediment trapping by a single plant was likely attributable to the sheltering effect created by the lower part of the above-ground plant body; the flexible upper portion of the plant body apparently contributed very little to sediment trapping. The loss of the upper part of the bodies of grasses via grazing should therefore have little effect on sediment trapping when the plants are solitary or very sparsely dispersed.