甘南境内高速公路干扰区生态修复适宜草种的活力及其应用

Analysis of seed vigor and use of different grass species in ecological restoration of expressway in Gannan,China

为向青藏高原地区(比如甘南州高速公路干扰区)生态修复提供高活力草种及合适的利用途径,本研究选取包括青海、甘肃、宁夏收获的3种中华羊茅(Festuca sinensis)、垂穗披碱草(Elymus nutans)、早熟禾(Poa annua)、无芒雀麦(Bromus inermis)、紫羊茅(F.rubra)、芨芨草(Achnatherum splendens)和醉马草(A.inebrians)9种禾本科植物,以及草木樨(Melilotus officinalis)、红三叶(Trifolium pratense)、多变小冠花(Coronilla varia)、沙打旺(Astragalus adsurgens)4种豆科植物为试验材料,在活力检测筛选的基础上,将试验材料播种到收集的卓合高速公路建设工程弃土(浅层黑土、深层黄土)且添加不同的改良剂(菌肥、草木灰以及两者混合添加)中。结果表明:仅中华羊茅、醉马草、红三叶和多变小冠花种子发芽势较高,且显著高于其他种子的发芽势(P<0.05);甘肃和宁夏产地的中华羊茅、醉马草、红三叶和多变小冠花发芽率在60%以上,而其他8种植物种子发芽率均较低;种子发芽指数仅醉马草和沙打旺较高,显著高于其他种子(P<0.05);种子活力指数为3种中华羊茅、醉马草、红三叶和沙打旺较高;青海产地的中华羊茅、垂穗披碱草的胚根和胚芽长以及幼苗含水量显著高于其他禾草(P<0.05);不同土壤类型和改良剂对禾草萌发、地上地下生物量有显著影响(P<0.05),具体表现为浅层黑土的发芽数较高,土壤改良剂中草木灰能显著提高4种牧草种子总萌发率与总生物量(P<0.05),表明黑土更适宜于4种牧草的生长,且同时添加草木灰有益于禾草的生长。研究结果为高寒地区公路工程建设中合理建植当地乡土草提供了理论和实践基础。

To provide suggestions for the selection and use of suitable grass species in the ecological restoration of an expressway on Qinghai-Xizang Plateau within Gannan Tibetan Autonomous Prefecture.We studied the seed germination characteristics of nine gramineae species,which included three ecotypes of Festuca sinensis harvested from Qinghai,Gansu,and Ningxia,Elymu snutans,Poa annua,Bromus inermis,Achnatherum splendens,Festuca rubra,Achnatherum inebrians,and four legumaceae species including Melilotus officinalis,Trifolium pratense,Coronilla varia,and (Astragalus adsurgens).On the basis of different germination indices,F.sinensis,E.snutans,P.annua,and F.rubra were planted in abandoned soil(black soil and deep loess soil)collected from a road construction area in Zhuhe,Gannan.The seeds were planted in different seasons(June and September)with different additives(microbe,plant ash,and a combination of microbe and plant ash).The results showed that only F.sinensis harvested from Gansu and Ningxia,as well as A.inebrians,T.pratense,and C.varia,had seed germination rates above 60%,whereas the germination rates were relatively low for the other eight grass species.In addition,the germination forces of A.inebrians,T.pretense,and C.varia seeds were substantially higher than those of the other seeds(P<0.05),and the germination indexes of A.inebrians and A.adsurgens seeds were significantly higher than those of the other seeds(P<0.05).The seed vigor indexes of three ecotypes of F.sinensis A.inebrians,T.pretense,and A.adsurgens were higherthe highest.F.sinensis harvested from Qinghai and E.nutans had considerable longer plumule and radicle lengths as well as higher seedling water content than the other grasses(P<0.05).Both soil and additive types significantly influenced seed germination and the growth of the four grasses(P<0.05).Surface black soil was more suitable for growing the four species,and the addition of plant ash was beneficial to plant growth.These results provide a theoretical and practical basis for the reasonable planting of native grasses when constructing highways in alpine regions.