秦岭松栎林建群种更新格局对种子扩散过程及影响因素的响应

The pine-oak mixed forest which is the most representative community in Qinling Mountains was being studied in this research. Taking the aim at explorations of responses of regeneration pattern to influencing factors of constructive species, the successional stage and stability of community, the diversified characteristics of succession trend, the main driving factor and its influencing mechanism and other important scientific problems, the research transects and community plots were established between mosaic distribution ecotone of pine and oak forest communities in the western, middle, eastern Qinling Mountains. The systematical research was carried out using plots regeneration survey, seed rain collection and seed bank survey, especially for artificial release seeds and seed fate tracking method. The findings were ⑴ to clarify and explain the differences of reproductive strategies among constructive species : Pinus tabuliformis, Quercus aliena var. acuteserrata, Pinus armandii basing on laws of its seed dispersal and influencing factors; ⑵ to study dynamics and its influencing factors of seedlings, saplings regeneration patterns of constructive species, and the link coupling between regeneration pattern and seed dispersal of the constructive species, as well as ecological factors, biological factors, and intrinsic relations among disturbed elements were comprehensively analyzed. Combining the above-mentioned ⑴and⑵ findings was to clarify interrelated process of regeneration pattern, dynamics and succession trends of pine and oak forest communities. The findings is expected to provide some scientific bases for occurrence and succession mechanism of pine-oak mixed forest in the further research in those areas, and gave guidances for establishment of forest health management technology system which conform to its own development laws and has meaningful practical value of pine oak forest.

以秦岭山地典型的松栎混交林群落为对象，针对建群种油松、锐齿栎、华山松更新格局对影响因素的响应，群落的演替阶段和稳定性，演替趋势的多元化特征、主要驱动因子及其影响机制等重要科学问题，分别在秦岭西段、中段、东段松栎林群落镶嵌分布区设立研究样带和群落调查样地，采用样方更新调查、种子雨收集、种子库调查以及人工释放种子、跟踪种子命运的方法，系统研究（1）建群种种子扩散规律及其影响因素，阐明不同建群种的生殖策略差异；（2）研究建群种幼苗、幼树更新格局动态及其影响因素，综合分析建群种更新格局和种子扩散过程、规律之间的耦合关系，以及和生态因子、生物因子、干扰要素之间的内在联系；通过（1）（2）研究，阐明松栎林群落建群种更新格局、动态与群落演替趋向间的相互关联性，为进一步深入研究松栎混交林群落的发生、演替机制提供依据；为构建符合其自身发展规律且具有实践价值的松栎林健康经营技术体系提供依据。

本研究以秦岭山地典型的松栎混交林群落为对象，系统研究该群落建群种种子扩散规律及其影响因素，阐明不同建群种种子及其生存策略差异，研究建群种幼苗、幼树更新格局和种子扩散过程之间的耦合关系。为进一步深入研究松栎林群落的发生、演替机制，构建符合自身发展规律且具有实践价值的松栎林健康经营技术体系提供依据。.项目实施过程中，选择有代表性的松栎混交林群落开展各项群落学调查，发现径级缺失是油松、华山松种群出现更新瓶颈的原因。群落空间结构表现为随机分布、生长中庸、中强度混交，随着演替进程，建群种种间竞争趋于激烈，群落物种种间关系逐渐趋于稳定共存。群落稳定性与海拔、坡度密切相关，符合多样性产生稳定性的理论。.通过设置样带、样方，持续监测建群种种子雨、种子库动态，开展种子扩散试验，不同建群种繁殖策略差异表现为生产数量的种间差异，年际间差异，种子雨高峰期的种间差异以及不同年份高峰期出现时间的差异。种子繁殖策略差异进一步影响种子扩散过程，啮齿动物在种子扩散过程中偏好就地取食油松种子，搬运取食或埋藏华山松、锐齿槲栎种子，将不同种子扩散至不同距离。凋落物覆盖、啮齿动物对种子定向扩散及扩散的微生境选择促进了松栎混交林更新格局的演变。.通过对建群种更新调查及与环境因素的关系研究，发现锐齿槲栎、油松和华山松3种建群种在松栎混交林群落内的更新均较为丰富，但后期幼苗状态存在差异，更新幼苗空间分布与成树分布存在一定分异。群落更新层物种分布受各类环境因素影响强度依次为土壤理化性质 > 林分特征 > 地形因素。土壤养分元素、枯落物厚度、草本层盖度、土壤水分、郁闭度对建群种幼苗幼树各有不同程度影响。坡向与土壤厚度显著影响锐齿槲栎群落物种多样性的变化，强度间伐措施下的华山松人工林林下植物多样性更高，具有更丰富的更新数量。.通过项目研究，已发表学术论文20篇，其中SCI收录7篇，培养博士1名，硕士5名。超额完成项目研究目标和规定的考核指标。