葎草种群自疏过程中幼苗构件性状及生物量分配变化  

Module traits and biomass allocation of Humulus scandens seedlings during population selfthinning

作　　者：樊星[1] 蔡捡 刘金平[1] 游明鸿[2] 范宣[1] 王思思[1] 

机构地区：[1]西华师范大学西南野生动植物资源保护省部共建教育部重点实验室,四川南充637009 [2]四川省草原科学研究院,成都610097

出　　处：《生态学杂志》2016年第11期2926-2934,共9页Chinese Journal of Ecology

基　　金：四川省科技支撑计划(2011NZ0064);校基金(11A035)项目资助

摘　　要：以雌雄异株攀援草本植物葎草为材料,通过每10 d测量1次,连续6次,测定幼苗期葎草种群的密度和高度、个体构件性状和生物量分配等参数,分析种群自疏过程中种群密度与个体构件性状及生物量分配的关系,研究葎草种群的自疏规律。结果表明:幼苗期葎草种群存在显著的自疏现象,种群密度60 d内下降了71%;幼苗期葎草由直立生长向横向生长时,种群密度和株高显著降低;自疏过程中存留植株的茎性状有显著变化,变化大小为节间长>主茎长>茎直径,节间长增加,叶性状变化大小为叶面积>叶柄长>叶厚>叶宽>叶长>总叶数>保留叶片数,根性状变化大小为总根长>根体积>根数>根长>最大根长;自疏过程中存留植株的构件生物量、单株生物量显著增加,而单位面积累积生物量呈阶段性下降;留存植株的地上生物量分配比相对稳定(P>0.05),根茎比和叶茎比有极显著变化(P<0.01);叶、茎、叶柄生物量与根生物量和地上生物量之间均呈极显著的异速关系(P<0.01),茎随地上生物量增长呈等速生长,而叶、叶柄和根随地上生物量增长呈异速生长,地上生物量与叶、茎、叶柄及根生物量极显著相关(P<0.01);茎生物量与密度的异速关系遵循最终产量恒定法则,叶、叶柄和根生物量并不满足-3/2或-4/3或-1自疏法则;地上和单株总生物量与密度极显著相关(P<0.01),存留单株的地上生物量和总生物量与密度的异速关系遵循最终产量恒定法则。Humulus scandens is a dioecious climbing herb. In April, a uniformly distributed wild H. scandens population was selected and managed only for controlling weeds. From the beginning of May, some parameters of H. scandens seedling, including density and height of population, individual’s module traits and biomass allocation, were determined for six consecutive times at an interval of 10 d. The purpose of this study was to analyze the relationships among population density, individual’s module traits and biomass allocation during population selfthinning, and to explore the selfthinning law of H. scandens population. The results showed that H. scandens seedling was characterized by a significant selfthinning phenomenon. Population density decreased by 71% within 60 days. During seedling from upright growth to lateral growth, density and height of population were significantly reduced. Due to selfthinning, stem traits of remained plants were significantly changed in the following order： internode length 〉 main stem length 〉 stem diameter for stem traits; leaf traits varied in the following order： leaf area 〉 petiole length 〉 leaf thickness 〉 leaf width 〉 leaf length 〉 total leaf number 〉 reserved leaf number; and root traits： total root length 〉 root volume 〉 root number 〉 root length 〉 maximum root length. Component biomass and single plant biomass of remained plants were significantly elevated, yet biomass per unit area declined gradually. Allocation ratio of aboveground biomass of remained plants was relatively stable （P〉0.05）, while the ratios of root to stem and leaf to stem changed significantly （P〈0.01）. There was highly significant allometric relationship among leaf, stem, petiole biomass, root biomass and aboveground biomass （P〈0.01）. Leaf and stem presented a constant growth pattern with the increase of aboveground biomass. Meanwhile, leaf, petiole and root presented an allometric growth pattern with the incr

关 键 词：种群 自疏 蓓草 雌雄异株 生物量分配 

分 类 号：Q948[生物学—植物学]