短花针茅生长和繁殖策略对载畜率的响应  

The Response of Growth and Reproduction for Stipa breviflora to Different Stocking Rates

作　　者：古琛[1] 赵天启[1] 王亚婷[1] 王玺[1] 贾丽欣[1] 赵萌莉[1] GU Chen;ZHAO Tianqi;WANG Yating;WANG Xi;JIA Lixin;ZHAO Mengli(Collage of Grassland, Resources and Environment, Inner Mongolia Agricultural University Hohhot, Inner Mongolia 010019, China)

机构地区：[1]内蒙古农业大学草原与资源环境学院,内蒙古呼和浩特010019

出　　处：《生态环境学报》2017年第1期36-42,共7页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(31660108;31460110);内蒙古农业大学草地资源教育部重点实验室资助项目

摘　　要：生长和繁殖是植物的两个最基本的生命过程,二者之间的资源分配是植物生活史策略的核心问题。为了响应家畜放牧的干扰,草原植物需要不断地在营养生长和生殖生长之间进行调节。试验以内蒙古荒漠草原为研究对象,采用4个载畜率水平完全随机区组试验设计,研究荒漠草原建群种短花针茅(Stipa breviflora)生长和繁殖策略对不同载畜率的响应,对揭示短花针茅应对放牧干扰的响应策略有重要的生态学意义,也可为荒漠草原生态系统的保护和放牧利用提供参考。结果表明:(1)短花针茅种群盖度在轻度放牧区显著增大,在重度放牧区显著降低(P<0.000 1),其种群和株丛地上生物量、高度均随载畜率的增大而显著降低(P<0.000 1),但密度随载畜率的增大而增大(P<0.000 1);(2)轻度放牧区短花针茅的分蘖数(P=0.048)和株丛径(P=0.023)显著高于其他处理,且分蘖节深度随着载畜率的增大而显著变浅(P=0.042);(3)轻度放牧显著增加了短花针茅的种子产量,重度放牧使之显著降低(P<0.000 1),且种子生物量占植株地上生物量的比例在轻度放牧区最高(P<0.000 1);(4)短花针茅总分枝数和生殖枝数在轻度放牧区最多(P<0.000 1),随着载畜率的增大而显著减少,重度放牧显著降低了生殖枝所占比例而显著提高了营养枝的比例(P<0.000 1)。短花针茅的生长、分蘖(无性繁殖)和有性生殖在轻度放牧区均显著升高,而随着载畜率的增大而显著降低,说明轻度放牧(载畜率为0.91sheep·hm-2·0.5 a-1)是短花针茅种群的最适载畜率,也是其生长和繁殖的载畜率阈值。Resource allocation between growth and reproduction,the two basic life processes,are the core of plant life-historystrategy.Plants have to balance the sexual and asexual reproduction to adapt to grazing disturbance.In our study,a completelyrandomized block design experiment with four different stocking rates was set up in the field to investigate the effects of differentstocking rates on the growth and reproduction of Stipa breviflora,the dominant specie on desert steppe in Inner Mongolia.It is ofecological significance to reveal the response of S.breviflora from grazing disturbance.This study provides a reference for theprotection of desert steppe ecosystem,as well as,grassland grazing management.Results showed that:(1)The foliage coverage of S.breviflora was higher under light grazing and lower under heavy grazing(P<0.0001),while the aboveground biomass both forcommunities and individual and height decreased(P<0.0001)but the density conversely increased(P<0.0001)with the increase instocking rates.(2)Both number of tillers(P=0.048)and diameter(P=0.023)of S.breviflora tussock increased under light grazing,and tillers depth decreased(P=0.042)with increasing stocking rates.(3)The seed yield and proportion of S.breviflora was highestwith light grazing but decreased in heavy grazing(P<0.0001).And(4)likewise,both the total and reproductive tillers of S.breviflora were highest(P<0.0001)under light grazing,and then decreased with increasing stocking rates,under heavy grazing,theproportion of reproductive tillers was decreased,while vegetative tillers’proportion increased(P<0.0001).Growth promotion of S.breviflora,as well as,tillers and reproduction were heightened by light grazing,but decreased with increase stocking rates.Resultssuggested that light grazing(stocking rate is0.91sheep?hm-2?0.5a-1)is the optimal stocking rate and the threshold for both of thegrowth and reproduction of S.breviflora in desert steppe of Inner Mongolia.

关 键 词：荒漠草原 放牧强度 种群特征 分蘖 有性生殖 

分 类 号：S812.29[农业科学—草业科学]