鹞落坪国家级自然保护区草本植物多样性及空间分布

鹞落坪国家级自然保护区森林群落研究主要集中于乔木层生物多样性、群落组成与结构及其维持机制，但对保护区林下草本层植物多样性及空间结构缺乏研究。以鹞落坪国家级自然保护区内落叶阔叶林11.56 km²永久大样地（以下简称大样地）林下草本植物为研究对象，探讨草本层植物多样性、空间分布格局及优势种的种间联结性和相关性。结果表明：（1）大样地内的草本植物共有52科134属195种，其中百合科、唇形科、堇菜科、菊科与毛茛科草本植物占主导作用。（2）大样地内草本植物优势种明显，多样性指数较高且整体分布较为均匀，其中北部阳坡物种多样性较低，南部阴坡、中部半阳坡的物种多样性较高。（3）七种空间格局分析方法均表明大样地内草本植物优势种呈现聚集分布。（4）大样地内10个草本优势种45个优势种对的χ²检验、联结系数AC检验、Pearson相关系数检验和Spearman秩相关系数检验结果显示，种对间正联结、正相关的数量多于负联结、负相关的数量；Spearman秩相关系数检验更具灵敏性；种间联结强度与相关度较弱，说明林下草本植物种间及与环境之间关系尚未达到相对稳定状态。对鹞落坪落叶阔叶林下草本植物调查与长期监测，为深入研究林下草本植物的生态功能、对林下草本植物资源的保护利用及自然保护区管理提供理论依据。

Diversity and spatial distribution of herbaceous species with deciduous broad-leaved forest in the Yaoluoping National Nature Reserve

The main protection objects of the Yaoluoping Nature Reserve are typical representative forest vegetation and the national key protected, rare and endangered animal and plant resources in the Dabie Mountain area. It is also an important water conservation forest reserve in the Dabie Mountains. The total area of the reserve is 123 km², which is divided into three functional areas. The core area is 21.2 km² (including Shifosi-Dachuanling core area, Diaojujing core area, Qilingou core area and Duozhijian core area), the buffer area is 28.4 km², and the experimental area is 73.4 km². This paper took the herbaceous plants under the deciduous broad-leaved forest 11.56 km² permanent sample plot in the Yaoluoping National Nature Reserve as the research objects, and then investigated the plant diversity, spatial distribution pattern, interspecific association, and correlation of dominant species in the herb layer. The main results are as follows:1. The herbaceous plants investigated in the sample plot belong to 52 families, 134 genera and 195 species. The floristic geographical compositions of herbaceous plants in the Yaoluoping sample plot are complex, covering many distribution types. Among them, there are more temperate elements, accounting for 60.44% of the total genera. The results showed that the temperate characteristics of deciduous broad-leaved forest communities were obvious. Tropical plants accounted for 18.66% of the total genera. The herbaceous plants in the sample plot had an obvious affinity to the temperate growth environment.2. Analysis of important values of 195 herbaceous plants in plot showed that the important values of Carex breviculmis, Carex brachyathera, Carex siderosticta, Elymus kamoji, Viola acuminata, Galium hoffmeisteri, Cardamine engleriana, Cardamine macrophylla, Carex sp., and Galium bungei accounted for 58.57% of the total, and they were the dominant species in the plot. Among them, the Carex breviculmis had a significant advantage in the plot.3. Species diversity not only reflects the species richness of community composition and the degree of uniform distribution among species, it also reflects the relationship between different physical and geographical conditions and the community, as well as the stability and dynamics of the community. It is an important feature of the combination of community organization. Through analysis of Simpson index, Shannon-Wiener index, and Pielou evenness index of herbaceous plants in the sample plot, it is found that the dominant species of herbaceous plants in this area are obvious, the herbaceous plant diversity is rich, and the overall distribution is relatively uniform. The area with high species diversity is concentrated in the central and southern corner of the river, and the species diversity on shady slope of the south is higher than that on sunny slope of the north.4. Diffusion coefficient (C), average congestion degree (m*), negative binomial parameter (K), cluster index (I), agglomeration index (PI), cassie index (C_A), green index (GI) and other methods were used to analyze the spatial distribution patterns of the dominant species. The species correlation was measured according to the 2×2 joint list and coefficient (AC) and χ² statistics. The results demonstrated that the herbaceous plants were mostly aggregated, and the positive correlation of species was higher than negative correlation, but the correlation intensity was low. It indicated that the community remained in the unstable succession stage.5. In the Spearman rank correlation test of the dominant populations in the large sample plot, among the 45 species pairs of the first 10 herbaceous dominant species, 27 species pairs showed positive correlation, accounting for 60.00% of the total species logarithm. Among them, the logarithm with extremely significantly positive correlation was 17, accounting for 37.78% of the total species logarithm, and the species logarithm with a significantly positive correlation was 1, accounting for 2.22% of the total species logarithm. The species logarithm with negative correlation among species pairs was 18, of which the species logarithm with extremely significant negative correlation was 9, accounting for 20.00% of the total species logarithm. The species logarithm with significantly negative correlation was 2, accounting for 4.44% of the total species logarithm. The total species logarithm which was not significant was 16 pairs, accounting for 35.56% of the total species logarithm. The results showed that the correlation among the dominant species was not strong, and the interspecific state was loose as a whole, which was consistent with the results of the dominant population χ²-test. The association test among herbaceous species in large sample plots of mountain deciduous broad-leaved forest showed that the scope of Pearson correlation coefficient test was for the data of continuous and linear relationship between two variables, normal distribution or near-normal unimodal distribution. However, the Spearman rank correlation coefficient test did not require the overall distribution shape of the two variables and the size of the sample size. The investigation and monitoring of herb under the deciduous broad-leaved forest provided an importantly theoretical basis for the effective protection and rational utilization of precious herb resources under the forest.