水杉是我国特有的孑遗植物,利川原生水杉母树资源占全球水杉母树资源的 99.43%,保存利川水杉母树资源十分必要,意义深远.本研究采用实地调查与资料收集的方法,了解利川水杉种质资源及其保护现状.目前水杉母树资源生存受到自然灾害、保存技术落后、资金投入不足、缺乏顶层规划设计以及周边社区人为活动等因素的综合影响.本文提出强化原生母树就地保护,用科学技术手段克服迁地保护中的难题,拓宽水杉原生母树种质资源保存资金渠道,加强宣传教育提高全民对野生动植物的保护意识等对策与方法有效保护水杉种质资源,供参考借鉴.
Choristoneura metasequoiacola Liu, 1983 is an important caterpillar species that specifically infests the leaves and branches of Metasequoia glyptostroboides Hu & W. C. Cheng 1948 with short larval infestations, long-term dormancy, and has a limited distribution in Lichuan, Hubei, China. The complete mitochondria genome of C. metasequoiacola was determined by using Illumina NovaSeq, and analyzed based on previously annotated sibling species. In total, we obtained mitochondria genome with 15,128 bp in length, circular in shape with a double-stranded closed ring structure, including 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and an AT-rich region. Of which the nucleotide composition was highly A + T biased, accounting for 81.98% of the whole mitogenome. Thirteen protein-coding genes (PCGs) were 11,142 bp; Twenty-two tRNA genes and AT-rich region were 1,472 and 199 bp, respectively. Phylogenetically, the relationship between Choristoneura spp. (containing C. metasequoiacola) and Adoxophyes spp. was closer than any other two genera from Tortricidae, and the relationship between C. metasequoiacola and C.murinana was the closest among nine sibling species from that genus, which helps to explain species evolution within the family Tortricidae.
[目的]探讨水杉Metasequoia glyptostroboides母树凋落物物理阻隔对水杉天然更新的影响,为解除水杉天然更新障碍及保护水杉种群提供科学依据.[方法]通过野外模拟试验,对不同类型凋落物(新鲜凋落物和自然凋落物)采用0(对照)、100、300、500、700、900 g·m?2的质量梯度,分别在种子下层和上层覆盖凋落物来探究凋落物对水杉幼苗出土及早期生长的影响.[结果]①凋落物对水杉种子出苗率和幼苗存活率产生抑制作用,在凋落物质量为300~900 g·m?2时抑制作用显著增强(P<0.05).②除在种子下层铺垫自然凋落物外,其余处理在凋落物质量为300 g·m?2时促进水杉幼苗苗高和地径生长,但与对照差异不显著(P>0.05);当凋落物质量高于300 g·m?2时,全部处理均抑制幼苗生长.随着凋落物质量的增加,对水杉幼苗根长的抑制作用逐渐增强.③随凋落物质量增加,水杉幼苗地上生物量和地下生物量呈先上升后下降的变化趋势,只有在种子下层铺垫300 g·m?2的自然凋落物处理后有一定波动,其余各处理均抑制幼苗地下生物量累积;当凋落物质量达500 g·m?2以上时,凋落物显著阻碍幼苗地上和地下生物量的累积(P<0.05).④同一凋落物质量下(>300 g·m?2),新鲜凋落物对水杉幼苗出土和早期生长的抑制作用大于自然凋落物,种子下层铺垫凋落物比种子上层覆盖凋落物的抑制作用更强.[结论]水杉母树凋落物对水杉幼苗出土和早期生长具有明显的物理阻隔作用,进而影响水杉更新生长.因此,建议在种子雨高峰期前,对水杉林下不同类型的凋落物进行及时清理,以促进水杉天然更新.
为了解自然保护区管理状况,提升保护区管理水平和实现保护区管理目标,以枟湖北星斗山国家级自然保护区总体规划(2013~2022年)枠及其实施情况为研究对象,基于枟自然保护区管理评估规范枠(HJ913-2017)对星斗山保护区管理状况进行评分,结果表明:(1)保护区规划内容包括保护管理工程、科研监测工程、公众教育工程、基础设施工程和可持续发展工程共计184项指标,完成率达53.79%;(2)保护区管理机构已健全,人员的编制总体上已落实;(3)保护区项目资金投入比例达43.48%,其中,中央投资占总投资的48.73%,地方配套占51.27%,单位未能自筹经费进行项目建设;(4)保护区总得分为75.5分,评估等级为"良",其中保护区管理基础得分相对较高,管理保障得分相对较低.说明星斗山国家级自然保护区总体的管理水平处于良好的状态.
为了研究水杉原生种群胸径、树高与树冠之间的关系,采用通径分析的方法对星斗山国家级自然保护区内的水杉原生种群不同林龄阶段的胸径、树高和树冠等进行分析.结果表明:各年龄阶段胸径对冠幅的直接作用均大于间接作用,胸径对于冠幅的影响均大于树高对冠幅的影响;树高对冠长率具有促进作用,且在成年林时作用最大;胸径对于冠形率的正向作用一直减小甚至成为负向作用.
水杉(Metasequoia glyptostroboides)原生种群天然更新困难,为探究其原因是否与繁殖特性有关,本文以其核心种质资源(40株个体)为对象,通过对生境、母树个体和种子性状的调查,并结合田间播种试验,分析其繁殖特性.以方差分析检测不同母树个体间种子性状、发芽率和幼苗生长特征的差异;采用相关性分析和多元线性回归模型分析个体性状对其种子、发芽率及幼苗生长的影响;通过Logistic模型拟合,分析幼苗生长的节律参数.结果 显示:(1)40株母树个体仅有7株产种,产种率仅为17.50%,且不同母树个体间产种量差异显著(P<0.05).(2)不同母树个体间的种子千粒重、种子发芽率、幼苗存活率和基径生长量均存在显著差异(P<0.05).(3)7株母树个体种子的平均发芽率为19.73%,幼苗平均存活率为73.42%,不同母树之间差异显著(P<0.05).(4)母树个体的胸径与种子千粒重、种子发芽率呈显著负相关(P<0.05),种子发芽率与幼苗存活率呈极显著正相关(P< 0.001),树高与幼苗存活率呈显著正相关(P<0.05)、与幼苗基径呈极显著正相关(P< 0.001).(5)母树树高对幼苗存活率有显著正效应(P<0.05),胸径对种子发芽率有显著负效应(p<0.05).(6)苗高、基径的生长符合“S”型生长曲线(R2≥0.928).水杉原生种群产种量低,种子发芽率低、幼苗存活率较低,且不同母树之间差异显著可能是造成其天然更新困难的原因.
基于鄂西南4个地段典型植被的调查数据,对川陕鹅耳枥种群结构与动态进行分析.结果表明:1)4个地段种群幼龄个体数量丰富,均属增长型种群;2)川陕鹅耳枥种群的胸径与树高呈显著正相关,胸径与树高异速生长明显;3)鄂西南种群死亡率和消失率均呈双峰型,在生长前期和中期达到高峰;存活曲线趋于Deevey-Ⅲ型,但各地段川陕鹅耳枥存活曲线在不同阶段呈现不同类型;4)生存分析表明,鄂西南川陕鹅耳枥种群总体呈现出前期锐减、中期稳定、后期衰退的特点.
AimsExploring the effects of topography on leaf functional traits across plant life forms is helpful to understand species diversity maintenance in forests.The objective of this study is to test how leaf traits among trees, shrubs and woody lianas respond to topographic variability distinctly.Methods Five leaf functional traits (leaf area, leaf thickness, leaf dry mass, leaf dry matter content and specific leaf area) were measured for 224 woody plant species with contrasting life forms (trees, shrubs and woody lianas) across 50 plots of evergreen and deciduous broadleaved mixed forests in Xingdou Mountain, Hubei Province, China.The variation in leaf functional traits of trees, shrubs and woody lianas were analyzed by one-way ANOVA.We tested the significance of the effect of topographic variability on leaf functional traits of woody plants by Partial Mantel test at community level and species level, respectively. Important findingsThe coefficient of variation of leaf functional traits in different life forms ranged from 23.42% to 110.45%, and there were significant differences in leaf functional traits among different life forms.At the community level, there was a significant positive correlation between altitude and tree leaf dry mass, shrub leaf area and woody liana leaf thickness.Slope only had significant influences on shrub and woody liana leaf area, and slope aspect had significant effects on shrubs leaf thickness.There was a significant positive correlation between leaf dry mass and specific leaf area.At the species level, the effects of slope and slope aspect on plant leaf functional traits were more significant than those of altitude, and the sensitivity in the responses of functional
Based on several comprehensive field investigations in Xingdoushan Nature Reserve in Hubei Province from 2013 to 2015,we collected 3 441 plant specimens. According to related origin information records in Flora Hubeiensis,Flora Republicae Popularis Sinicae and Flora of China,we found the distribu-tion of 45 new seed plants in Hubei Province,involving 36 genera in 25 families.
[目的]探讨水杉原生母树适宜的硬枝扦插技术.[方法]在湖北星斗山国家级自然保护区小河片区水杉原生母树种群调查的基础上,采用不同扦插基质、不同硬枝插穗处理方式及不同胸径的水杉原生母树所采集的硬枝插穗进行扦插试验,探讨其扦插成活率及影响扦插成活率的因素.[结果]以沙为基质,清水处理水杉原生母树的枝条扦插成活率最高,达到16.97%.水杉原生母树胸径对插穗扦插成活率有显著影响,胸径为80 ~ 120 cm的水杉原生母树所采集的硬枝插穗扦插成活率最高.胸径小于40 cm的水杉原生母树插穗适宜用沙作基质,50 mg/L NAA处理插穗24h后进行扦插,效果最佳;而胸径为40 ~ 59 cm、60 ~ 79 cm、80~99 cm、100~119 cm、≥120 cm的水杉母树用沙作基质,清水浸泡处理插穗后直接进行扦插,效果最佳.[结论]该研究可为更好保存现存水杉原生母树遗传资源提供科学依据.
于2013-2015年对湖北星斗山国家级自然保护区进行多次全面野外调查,采集植物标本3441号,并对其种子植物区系特点进行了研究.结果显示,该保护区共有野生种子植物138科678属1617种,其中裸子植物6科15属19种,被子植物132科663属1598种.区系分析表明,热带科(66.06%)多于温带科(33.94%),这与该区曾经历过古热带的历史背景相吻合;属级水平上则为温带属性(58.45%)强于热带(41.55%);中国特有种623个(占总种数的38.53%),均与四周区域所共有,反映出东西南北植物区系在此交汇渗透的态势;这些均表明该区种子植物区系成分不但复杂多样,而且还具有过渡区域的特点;保护区内植物区系还具有古老、残遗的特性,一些古老的残遗植物在该地有良好的原生群落分布;保护区内特有树种和珍稀濒危植物也很丰富,具有很大的保护价值.
自然保护区的建设是生态文明建设中的一个系统工程,搞好自然保护区的建设将更好地维护生态安全和建设生态文明,是开展生态文明建设的重要载体;美丽恩施的建设是一项综合工程,但是生态文明建设是其中重要一环,因此,加强恩施州自然保护区的建设,保护生态资源、培育生态文化、发展生态经济,努力建设生态恩施,将有效促进生态恩施、美丽恩施建设进程。
本文通过分析在林木育种中使用的分子标记技术、基因生物技术等,从而在一定程度上促进当地林木育种工作,提高育种效率,丰富生物资源的多样性。