藏北高寒草甸及高寒草原凋落物水浸提液对种子发芽的影响  

Effects of water extracts from litter of alpine meadows and grasslands in northern Tibet on seed germination

作　　者：张鹤 叶彦辉[1] 李文成 赵宁宁 吕思敏 王向涛 张志新[3] ZHANG He;YE Yanhui;LI Wencheng;ZHAO Ningning;LYU Simin;WANG Xiangtao;ZHANG Zhixin(College of Resources and Environment,Tibet University of Agriculture and Animal Husbandry,Nyingchi 860000,Tibet,China;Faculty of Animal Science,Tibet University of Agriculture and Animal Husbandry,Nyingchi 860000,Tibet,China;Northwest Agriculture and Forestry University,Yangling 712100,Shannxi,China)

机构地区：[1]西藏农牧学院资源与环境学院,西藏林芝860000 [2]西藏农牧学院动物科学学院,西藏林芝860000 [3]西北农林科技大学草业与草原学院,陕西杨凌712100

出　　处：《草业科学》2024年第11期2535-2544,共10页Pratacultural Science

基　　金：国家自然科学基金项目(42161012);西藏自治区重大科技专项(XZ202201ZD0005G02)。

摘　　要：高寒草原和高寒草甸是藏北草地重要的草地类型,围栏封育是高寒草地重要恢复方式,近年来被广泛应用于藏北草地恢复中,而长期围封会导致凋落物堆积,影响植被更新。为探究该两类草地凋落物对种子发芽的具体影响,本研究使用不同浓度的凋落物水浸提液模拟雨水淋溶,探究了其对藏北优势种及伴生种种子发芽特征的影响。结果表明:高寒草甸凋落物水浸提液对种子发芽的影响更明显,其中高寒草原凋落物水浸提液对种子发芽率、发芽势、平均发芽时间与发芽指数的抑制最高分别为蒸馏水对照组的75%、75%、79%、64%,而高寒草甸凋落物处理中各指标则达到对照组的52%、53%、66%、64%;与其他物种相比,凋落物水浸提液对于矮火绒草(Leontopodium nanum)发芽指数的抑制作用更为明显,对钉柱委陵菜(Potentilla saundersiana)发芽率有促进效果。此外,紫花针茅对于凋落物化感作用的影响更具有耐受性;而凋落物化感作用对钉柱委陵菜的发芽具有促进效果。因此,在未完全退化草地恢复中可以选择紫花针茅与钉柱委陵菜作为补播种;在使用围栏封育作为退化草地修复方式时进行凋落物清理可有效提高种子发芽,从而提高群落密度,有利于退化草地的恢复。Alpine grasslands and meadows are important grassland types in northern Tibet.Fencing is an important restoration method for alpine grasslands and has been widely used in grassland restoration in recent years.Long-term enclosure can lead to litter accumulation and affect vegetation renewal.This study used different concentrations of litter water extracts to simulate rainwater leaching and explore their effects on the germination characteristics of local dominant and associated species to investigate the specific effects of alpine grasslands and meadows on seed germination.The results showed that the alpine meadow litter water extract had a more significant effect on seed germination.The alpine grassland litter water extract had the highest inhibition on seed germination rate,germination potential,average germination time,and germination index,which were 75%,75%,79%,and 64%of the control group,respectively.However,in the alpine meadow litter treatment,four indicators reached 52%,53%,66%,and 64%of the control group.Compared with other species,the inhibitory effect of water extract from litter on the germination index of Leontopodium nanum is more significant,while the germination rate of Potentilla saunderiana improved under all treatments.In addition,Stipa purpurea was more tolerant to the effects of litter allelopathy.The allelopathic effect of litter had a promoting effect on the germination of Potentilla saundersiana Therefore,S.purpurea and P.saundersiana can be selected as reseeding in the restoration of incompletely degraded grassland.When fencing is used as a restoration method for degraded grassland,litter removal can effectively improve seed germination,thereby increasing community density,which is conducive to restoring degraded grassland.

关 键 词：藏北高寒地区 草地 凋落物 化感作用 水浸提液 植被更新 

分 类 号：S812[农业科学—草业科学]