为定量评价木林子天然林不同恢复阶段林分结构特征变化及森林恢复现状,以木林子自然保护区内皆伐后自然恢复24、39 a的次生林及未受人为干扰的原始林为研究对象,通过林分空间结构参数分布、径阶-空间结构参数联合分布来量化描述林分径阶和空间结构特征,并采用林分空间结构指数(I)和林分空间结构距离(D)综合评价不同恢复阶段林分整体结构特征.结果表明:木林子天然林不同恢复阶段林分均混交良好,随恢复时间的推移,该林分水平分布格局整体趋势由聚集分布向随机分布发展,大小分化度呈先增加后降低的趋势,但始终趋于均衡状态.空间结构参数方差检验表明,在自然恢复过程中,大小比数、混交度能更快地趋于合理,而角尺度则需要较长时间的恢复.径阶-空间结构特征表明,各个恢复阶段林木均以随机林体为主,其中原始林林分中随机分布格局下极强度混交状态的林木胸径更大.不同恢复阶段,绝对优势等级林木中原始林的径阶区间最广.相较于24年生及39年生次生林林分,原始林空间结构最优,林分空间结构指数、林分空间结构距离分别为0.724、0.544.皆伐后自然恢复24、39 a的次生林需较长时间才能达到原始林的结构状态.

To explore the population quantitative characteristics and regional distribution of wild Viburnum plants in Southwest Hubei, and reveal the survival status and development trend of the following five Viburnum species: V. erosum, V. betulifolium, V. sympodiale, V. setigerum and V. dilatatum. A total of 27 hm2 dynamic monitoring stands were set up in Jinzi Mountains National Forest Farm, Mulinzi National Nature Reserve and Qizimei Mountains National Nature Reserve in Southwest Hubei. The age structure, dynamic quantitative analysis and static life table of five Viburnum species were used to explore the population structure, dynamic characteristics and future development potential of Viburnum plants. The results were as follows: (1) The distribution area and population size of Viburnum plants in Southwest Hubei were significantly different. (2) The age structure of the five Viburnum species displayed as the pyramidal type summarized from population structure and dynamic analysis. The number of individuals of each population was large at the young stage (89.48% of V. erosum in Jinzi Mountains, 76.38% of V. betulifolium, 67.24% of V. erosum in Mulinzi, 62.11% of V. dilatatum, 56.53% of V. sympodiale, 58.44% of V. setigerum), and only a small proportion of individuals (0.18% of V. erosum in Jinzi Mountains, 0.85% of V. betulifolium, 3.29% of V. erosum in Mulinzi, 3.97% of V. dilatatum, 8.37% of V. sympodiale, 2.79% of V. setigerum) at the old stage. The young stage plants of five Viburnum species all had strong growth potentials but were sensitive to external disturbances. (3) The survival quantity of the five Viburnum species was decreasing monotonically with increasing age class presented by static life tables. Except for V. setigerum, the life expectancy reached peak at the young age, all the other Viburnum species populations reached the peak at the middle age. The change trend of mortality rate and vanish rate were similar, but the fluctuation of vanish rate and mortality rate curves were different among different species. The survival curves were tended to be Deevey-Ⅱ type. (4) The four survival function curves showed that all five Viburnum species populations exhibited a substantial decrease at the early stage, stabilization at the middle stage, and decline at the late stage. To sum up, plant resources of Viburnum species are abundant in Southwest Hubei. Therefore, it is scientific and feasible to exploit Viburnum plants rationally. At the young stage, artificial thinning can be carried out appropriately to improve the preserving rate. During the stable middle stage, the dominant species which have good ornamental characters can be selected for appropriate development and utilization. However, some species need to be protected to maintain biodiversity in this area.

为查明水杉天然更新的关键障碍因素,探索促进水杉天然更新的有效途径,在野外原生境中选择5株水杉母树作为研究对象,以水杉母树为中心设置样圆,在样圆内采用不同林下处理方式(群落阻隔、林下活地被物阻隔、凋落物阻隔和无阻隔)进行分区试验,研究植被和凋落物对水杉天然更新的影响.结果表明:不同林下处理方式对水杉幼苗更新密度、存活率、苗高、地径、根长、叶片数量、叶面积、地上生物量和地下生物量有极显著影响(P<0.01);幼苗萌发生长指标均在无阻隔区达到最大值,再由高到低依次是凋落物阻隔区、林下活地被物阻隔区、群落阻隔区.水杉林下活地被物、凋落物和群落环境均是造成水杉天然更新困难的障碍因素,对水杉种子萌发和幼苗生长抑制程度的排序为:群落环境>林下活地被物>凋落物.水杉幼苗苗高的生长动态变化符合S型生长曲线(R2≥0.893),4种处理方式的水杉幼苗更新密度均呈倒"V"形分布.无阻隔处理显著促进了水杉幼苗的天然更新,其存活率、苗高、地径、根长、叶片数量、叶面积、生长速率及生物量等指标均最高;今后在水杉种群保护和管理中,应适当清除林下活地被物和凋落物,为水杉种子萌发和幼苗生长提供适宜环境,促进水杉种群天然更新.

[目的]探究林分空间结构、物种多样性随尺度变化的规律及林分空间结构与物种多样性的相互关系,为鄂西南常绿落叶阔叶混交林可持续经营提供科学依据.[方法]以鄂西南七姊妹山自然保护区、木林子自然保护区和金子山国有林场3个研究区的典型植被——亚热带常绿落叶阔叶混交林为研究对象,基于各研究区大样地调查数据,分析从20 m×20 m到200 m×200 m不同尺度下,林分空间结构指标和物种多样性指数及其随尺度变化的规律,结合Pearson相关系数法解析尺度变化影响下的空间结构指标与物种多样性的相关性.[结果]鄂西南地区常绿落叶阔叶混交林中物种丰富,常见优势乔木树种为川陕鹅耳枥、多脉青冈和锥栗.林分空间结构特征在尺度 ≥120 m×120 m后变化趋于稳定,整体表现出微聚集分布、大小分化中庸且混交良好的状态.不同尺度上林分空间结构参数角尺度与林分物种多样性存在中度相关性(P<0.01),其他结构参数与林分多样性不存在相关性.[结论]鄂西南亚热带常绿落叶阔叶混交天然林,林分空间结构调查的最适尺度为120 m×120 m;不同研究尺度下,角尺度是林分空间结构影响物种多样性的一个关键因子.

基于湖北省利川苏马荡和英山桃花冲2个风景区的森林资源特点与实地调查数据,依据《森林生态系统服务功能评估规范》(GB/T 38582-2020)定量评估2019年湖北省森林风景区生态系统服务价值.结果表明,苏马荡风景区的森林生态服务总价值为3.94亿元/年,以涵养水源价值和固碳释氧价值主(共占79.56％);生态服务贡献最大的是针阔混交林,其次为马尾松林、柳杉林、日本落叶松林和杉木林.桃花冲风景区森林生态服务总价值为5.47亿元/年,涵养水源价值在森林生态系统服务价值所占比例最大,其次为森林游憩价值、固碳释氧价值、生物多样性保育价值、保育土壤价值、林木积累营养物质价值和净化大气环境价值;森林生态服务价值中针叶林贡献最高,其次是针阔混交林、阔叶林.研究结果客观反映这2个典型区域森林生态体系建设取得的成果和对经济社会发展的贡献,同时可为湖北省相关部门"两山"转化和"双碳战略"实施提供依据,对区域森林经营管理水平的进一步提升、实现森林可持续发展具有重要意义.

Tree biomass equations are the most commonly used method to estimate tree and forest biomass on various spatial and temporal scales because of their minor damage, ease of use, and high relative accuracy. The systematic compilation of models for the biomass of mixed evergreen and deciduous broad-leaved forest (a unique and essential class of typical vegetation types in the subtropical zone of China) has not been reported so far. In this paper, we compiled a species list through an inventory of 28.9 hm2 of mixed evergreen deciduous broad-leaved forests in southwestern Hubei Province with fixed detection sample plots, produced a species list, and used it to retrieve, collect and establish a model dataset of woody plant biomass in subtropical mixed evergreen and deciduous broad-leaved forests. The species list contains a total of 665 biomass models in 167 groups as well as the information corresponding to each mode, such as the plant species name, Latin name, plant life type, plant components calculated by the model, model independent variables, measurement units and ranges of independent variables, model correlation coefficient or coefficient of determination, model sample size, climate zone, and soil type. is also recorded. By establishing this dataset, this paper not only provides essential information for in-depth research on the productivity and carbon sink of this specific vegetation but also serve as a scientific basis for the management of this type of forest, the conservation of biodiversity, and the evaluation of forest ecological benefits.