优良水土保持植物——芨芨草

芨芨草 (Achnatherum splendens)又称积极草、席芨草等 ,属禾本科芨芨草属。多分布于我国北方 ,在黄土高原常分布于道路、村庄及沟坡陡坎上 ,多呈零星块状分布 ,集中连片较少。1　生物生态学特性芨芨草为多年生草本植物 ,构成紧密的丘状草丛 ,丛径一般为 0 .5～ 1 .0 m,茎秆直立、坚硬 ,株高 0 .6～ 1 .8m。叶片坚韧、卷折 ,长 0 .3～ 0 .6 m。园锥花序 ,长 0 .3～ 0 .5 cm,小穗长 6～8mm,灰绿带紫色 ,在黄土高原多为 6～ 7月开花 ,8月中旬到 9月上旬种子成熟 ,芒自外稃齿间伸出 ,不扭转 ,易脱落。根粗坚韧 ,外被沙套 ,须根发达 ,成庞大根系 ,入土深达 0 .5～ 1 .5 m,根直径均达 0 .2～ 0 .3cm,根幅在 1 .5～ 2 .0 m,其根上有白色毛状菌根。在沙质棕钙土上 ,芨芨草有明显分蘖节位移现象 ,在放牧过度地段上 ,由于土壤坚实 ,即盐分集中在土壤上层 ,使之毛细管现象加速土壤干燥 ,因此 ,从土壤的剖面观察到残存的大量死根 ,即活根系集中于剖面的上部 ,由于根量的减少 ,引起分蘖数减少 ,如不合理放牧或刈割利用...

芨芨草在黄土边坡治理中的应用效果

针对黄土高原铁路、公路、大坝及农田地埂边坡长期裸露的水土流失与生态环境问题,选择禾本科植物-芨芨草,进行了为期10年的引种、栽培、生理生态特性与水保等方面的综合开发利用研究。结果表明,芨芨草具有耐旱、耐盐碱、耐瘠薄、抗风沙和极强的固土护坡作用,采用的包衣穴播、分根栽植、基茎扦插3大栽培技术,使芨芨草植株在长期干旱裸露的边坡能快速形成密集的地上部分和发达的根系,固结土壤,防止地表径流冲刷土壤,保护了铁路、公路、大坝及农田地埂边坡的生态安全,为我国西部同类型区的边坡治理,提供了抗逆性较强的优良禾本科植物与配套的栽培技术体系。

青海湖地区围栏封育芨芨草种子形态及其萌发特性

以青海湖地区三角城种羊场的芨芨草(Achnatherum splendens)为观测对泉,研究围栏内外芨芨草的种子外观特征差异,及其在5,10,15,20,25,30℃时的萌发特性,以期评价围栏封育对种子形态和萌发特性的影响.结果表明,围栏内芨芨草种子无论是颗粒大小,还是饱满程度均好于围栏外;在温度低于5℃时,芨芨草种子将不萌发,随着温度的升高,发芽率不断上升,高于25℃发芽率有下降的趋势.低温或高温均不利于种子萌发,即低于20℃或超过25℃萌发均受到不同程度抑制,芨芨草种子萌发适宜温度为20～25℃.围栏内芨芨草种子的萌发状况好于围栏外.

The floristic of the family Gramineae of Karakorum and Kunlun area, China

There are 47 genera and 161 species of Gramineae except the cultivated species in the area of the Karakorum and Kunlun Mountains. The results of research on the distribution of the genera and species of Gramineae in the Karakorum and Kunlun Mountains show that (1) The Gramineae mainly contains elements of North Temperate, rich Old Word Temperate and other Temperate. It is obvious that the floristic nature of Gramineae in the Karakorum and Kunlun Mountains is the North Temperate; (2) All Pantropic genera can stretch to the Temperate Zone in this region, which all parts of the Pantropic type are the Temperate nature to a certain degree. For example, Erianthus ravennae from mediterranean to the Karakorum and Kunlun Mountains through the Central Asia; (3) As most genera of Grasses are the type of Temperate and the Frigid Zone, they have distinct floristic characteristics of mountainous and plateau flora such as Orinus, Alopecurus, Elymus, Trisetum, Littledalea, Elytrigia, Stephanachne and Paracolpodium etc. All of these indicate adaptive phenomenon of alpine specialization and cold-xerophilization on Grasses in this area; (4) Endemic genus of Gramineae is absent due to its nature and history and the endemic species are also rare in the Karakorum and Kunlun Mountains. Most of the genera with one or fewer species have originated from its relative and widespread genera, such as Ptilagrostis from Stipa, Timouria from Achnatherum, and so on; (5) Flora of the Karakorum and Kunlun Mountains is most closely related to the flora of Tibet, and is also extensively to its adjacent areas.

Notes on grasses (Poaceae) for the Flora of China, VI. New combinations in Stipeae and Anthoxantham

When Oryzopsis is confined to the type species, Chinese species are placed in Achnatherum and Piptatherum. This necessitates the following new combinations: Piptatherum grandispiculum, Piptatherum aequiglume var. ligulatum, Piptatherum tibeticum var. psilolepis.. Piptatherum. munroi var. parviflorum, Achnatherum henryi. and Achnatherum henryi var. acutum. Achnatherum henryi is lectotypified. The new name Piptatherum kuoi replaces the illegitimate name Piptatherum obtusum, and this species is lectotypified. Hierochloe potaninii is transferred to Anthoxanthum as A. potaninii, as Hierochloe is regarded as a synonym of Anthoxanthum. All the grass taxa (Poaceae) listed are endemic to China.

《马可波罗游记》中记载的肃州毒草及其生态环境背景调查

调查了《马可波罗游记》所记载的中国古代肃州引起牲畜中毒的毒草类型、分布特征及其发育地的生态环境背景。结果表明：在马可波罗当年旅行经过的肃州地区，狼毒，Stellera chamaejasma．棘豆Oxytropis，醉马草Achnatherum inelrians3种毒草大面积分布,已泛滥成灾,造成了数万头(只)牛、羊等家畜大量中毒死亡，严重影响了当地畜牧业的发展。肃南县是毒草生态灾害的重灾区，狼毒、棘豆、醉马草在该区广泛发育。狼毒、醉马草、黄花棘豆O.ochrantha发育在海拔：3000m左右、降水量近300mm的祁连山中高山区草原生态环境：小花棘豆O.glabra分布在降水量不到100mm、蒸发量可达2900mm、严重盐碱化的明花区走廊荒漠草原生态环境。棘豆植物分布区地理位置和牲畜中毒征状说明肃南县的棘豆毒草很可能是《马可波罗游记》中所记载的引起牲畜中毒的毒草。