阔叶红松混交林连根拔起倒木及其丘坑微立地特征对幼苗更新的影响

Continuous and located studies on the influence of characteristics of uprooted treefalls, microsites with pits and mounds on the seedling regeneration will be performed in different stand types of Korean pine broadleaved mixed forest. On fine scale, the characteristics of uprooted treefalls(tree species, treefall direction, its microrelief condition, formed dating and decayed levels, DBH, height, volume, biomass, its soil type, litter and mineral soil thickness, soil physico-chemical properties, et al.), their formed pits and mounds (geometric featureslength, including respective width, depth, height, thickness, surface area, volume, and formed dating, et al.) will be explored. On stand scale, the characteristics of pits and mounds formed by uprooted treefalls (their area proportion, formation age and distribution, disappearing period, return period, et al.) will be revealed; samples or sub-samples will be set up within the micorsites of uprooted treefalls,.and pits and mounds as well as closed stands without the disturbance(intact site), their seed bank and seed rain, and seedling regeneration status in these samples or sub-samples for different stand types of Korean pine broadleaved mixed forest. The relationship between these characteristics of uprooted treefalls, their formed pits and mounds, and seedling regeneration will be illustrated on both fine scale and stand scale.This study will provide the reference for suitable microsite determination for the seedlings of Korean Pine and other accompanied tree species and basic data and technical support for artificially simulated regeneration and promoted natural regeneration.

通过对红松混交林不同林型连根拔起倒木及其形成的丘坑微立地特征与幼苗更新的连续定位研究，在细尺度上探讨连根拔起倒木特征(树种名称、树倒方向、微地形、形成年龄和腐烂等级、胸径、树高、材积、生物量、微立地土壤类型、凋落物和土层厚度及土壤理化性质和生化特性等)及其丘坑微立地特征(几何特征和形成年龄等)；在林分尺度上，揭示树木连根拔起形成倒木特征(形成频率、空间分布格局等）及丘坑微立地特征（面积比例、形成年龄及分布、微立地空间分布格局、消失期和轮回期等）；在掘根倒木、丘坑微立地以及未干扰的郁闭林分内，设置调查样方或小样方，分别调查不同林型连根拔起倒木、丘坑微立地上红松及其伴生树种的种子库、种子雨以及幼苗更新状况，分析它们的空间分布格局。阐明以上两个尺度上连根拔起倒木及其丘坑微立地特征对幼苗更新的影响。为确定红松及其伴生树种幼苗更新的适宜微立地提供参考，为人工模拟和促进天然更新提供基础数据和技术支撑。

树木连根拔起是东北东部山区红松天然混交林常见的干扰类型之一，但迄今对其形成的丘坑微立地特征及其对幼苗更新的影响以及多因素互作机制尚不清楚。此项研究采用样地设置、野外调查与模拟播种和发芽试验、土壤和植物样品采集、基于自动气象站的微气候因子连续监测、室内模拟播种和发芽实验、样品分析和数据统计等相结合的方法，从连根拔起倒木单木和林分尺度上，探讨了以下问题：①不同林型天然红松混交林连根拔起倒木与丘坑复合体形态特征及其影响因素；②不同林型树倒林隙内微立地类型的土壤微团聚体组成及其分形特征；③林型和微立地类型及其土壤性质对土壤抗侵蚀能力的影响；④云冷杉林林隙内倒木腐烂等级及其微立地类型对土壤理化性质的影响；⑤红松天然针阔混交林主要树种空间格局及其关联性；⑥云冷杉红松林内优势种群的空间格局及种间关联性；⑦阔叶红松混交林不同大小林隙地表温度和浅层土壤温度的时空异质性；⑧不同林型红松林土壤真菌群落组成和多样性；⑨不同林型红松林nosZ反硝化微生物群落组成和多样性分析；⑩不种林型原始红松林土壤nirK型反硝化微生物群落结构和多样性；⑪不同林型天然红松混交林林隙大小和枯叶分解对土壤微生物碳的影响；⑫影响不同林型天然红松混交林林隙更新的土壤特征因子；⑬外源有机物与温度耦合作用对红松阔叶混交林土壤有机碳的激发效应；⑭椴树红松林林隙边缘木特征研究；⑮三种低分子质量有机酸对温带典型林型土壤无机磷组分的影响；⑯椴树红松林林隙大小与枯叶分解对土壤香草酸含量的影响；⑰红松天然林林隙特征及其边缘木的生长释放；⑱云冷杉红松林掘根倒木及其微立地对凋落叶分解速率及养分释放的影响；⑲椴树红松林不同微环境下凋落叶的分解动态；⑳红松天然混交林种子库和种子雨特征；㉑万年藓对红松更新的影响及其机制；㉒两种林型天然红松林掘根风倒区微立地内植物的碳氮化学计量特征。旨在阐明以上两个尺度上连根拔起倒木及其丘坑微立地特征对幼苗更新的影响，为确定红松及其伴生树种幼苗更新的适宜微立地提供参考，为人工模拟和促进天然更新提供基础数据和技术支撑。