摘要
为了测度一年生和多年生豆禾混播草地的超产效应与植物多样性效应的关系,明确一年生和多年生混播草地的高产优势,探索豆禾混播草地多样性效应和超产效应对其生态功能的响应机制,于2013–2015年在新疆伊犁地区昭苏盆地开展了3年的牧草产量观测试验。该试验设置3种牧草混播种类和混播比例,分别为一年生豆禾混播草地(2种牧草混播, AM2)和多年生豆禾混播草地(2种牧草混播, PM2;4种牧草混播, PM4;6种牧草混播, PM6),豆禾混播比例分别为6:4、5:5和4:6。结果表明:1) 2013、2014年和3年平均值AM2的超产幅度小于PM2和PM6, 2015年AM2的超产幅度大于PM2、PM4和PM6;混播群落生产力与群落组分中生产力最高产物种单产以及各组分种平均单产的差值表现出相似的规律。2) 2013、2014年和3年平均值AM2的互补效应大于PM2、PM4和PM6,AM2的选择效应则远小于互补效应,PM2、PM4和PM6的互补效应则比较稳定。3)物种丰富度和物种均匀度与牧草产量(群落生产力)大部分情况下呈单峰的"饱和上升型"模式,分别在4种牧草混播和豆禾混播比例为5:5时,具有较高生产力。4)多年生豆禾混播草地的互补效应、选择效应和多样性净效应均随生长年限的延长而呈下降趋势,也导致了超产幅度、超产效应及其稳定性的下降。由此可见,在建植初期,互补效应和选择效应共同主导了多年生豆禾混播草地的超产效应,而随着生长年限的延长,选择效应则成为主要影响因素;一年生豆禾混播草地的超产效应则一直受互补效应的影响。
Aims Our objective was to explore mechanisms underlying the effects of transgressive overyielding and plant diversity effects associated with legume-grass mixtures in Zhaosu Basin, Yili Prefecture, Xinjiang Uygur Autonomous Region, China. Methods Replicate plots(n = 3) were sown in 2013 as legume and grass monocultures(8 in total, including Vicia sativa, Avena sativa, Onobrychis viciaefolia, Bromus inermis, Trifolium pratense, Phleum pratense, Medicage sativa, Dactylis glomerata), a two-species mixture(AM2, annual legume and grass;PM2, perennial legume and grass), a four-species mixture(PM4, 2 perennial legumes and 2 grasses), a six-species mixture(PM6, 3 perennial legumes and 3 grasses), and three mixed-ratio combinations(legume : grass = 6:4, 5:5 and 4:6). Total plot productivity was measured as forage yield(dry matter) each summer between 2013 to 2015, which were used to calculate transgressive overyielding effect(OV), transgressive overyielding effect 1(OV1), and transgressive overyielding effect 2(OV2). Plant diversity effects were determined by calculating the complementary effect(CE), selection effect(SEF), and net biodiversity effects(?Y). Important findings The OV amplitudes of AM2 in 2013, 2014 and 3 years average were less than those of PM2 and PM6. The OV amplitude of AM2 in 2015 was greater than those of PM2, PM4 and PM6. The difference between the productivity of the mixed community and the yield of the most productive product species in the community components and the average yield of each species showed similar laws. CE of AM2 in 2013, 2014, and 3 years average was greater than PM2, PM4 and PM6 in the respective years. While SEF were much smaller than CE in AM2, changes in CE were relatively stable in PM2, PM4 and PM6. Fitted curves of species richness, species evenness, and forage yield(community productivity) predominantly showed a single maximum in PM4, yet productivity was highest in the 5:5 ratio plot. CE, SEF, and ?Y in perennial legume-grass mixtures decreased over time, which also led to declines in OV amplitude, OV1 and OV2, and their stability. Thus, in the initial study year, CE and SEF jointly dominated OV, OV1 and OV2 in perennial legume-grass mixtures. Over the next two growing years, SEF became the main factor that influenced OV, OV1 and OV2 in perennial legume-grass mixtures. OV, OV1 and OV2 of annual legume-grass mixtures were all influenced by CE from 2013 to 2015.
作者
黎松松
王宁欣
郑伟
朱亚琼
王祥
马军
朱进忠
LI Song-Song;WANG Ning-Xin;ZHENG Wei;ZHU Ya-Qiong;WANG Xiang;MA Jun;ZHU Jin-Zhong(College of Pratacultural and Environmental Science,Xinjiang Agricultural University,Ürümqi 830052,China;Xinjiang Key Laboratory of Grassland Resources and Ecology,Ürümqi 830052,China)
出处
《植物生态学报》
CAS
CSCD
北大核心
2021年第1期23-37,共15页
Chinese Journal of Plant Ecology
基金
新疆维吾尔自治区高校科研计划重点项目(XJEDU2019Z18)
农业农村部“国家牧草现代产业技术体系”项目(CARS-34)
国家自然科学基金(31660692)
国家重点研发计划(2017YFE0109200)。
关键词
物种丰富度
物种均匀度
超产效应
互补效应
选择效应
多样性净效应
生长年限
species richness
species evenness
transgressive overyielding effect
complementarity effect
selection effect
net effect of biodiversity
growth years