College of Forestry, Guizhou University, Guiyang, Guizhou, China.
PLoS One. 2023 Jun 30;18(6):e0286722. doi: 10.1371/journal.pone.0286722. eCollection 2023.
The distribution pattern of species diversity along various elevation gradients reflects the biological and ecological characteristics of species, distribution status and adaptability to the environment. Altitude, a comprehensive ecological factor, affects the spatial distribution of species diversity in plant communities by causing integrated changes in light, temperature, water and soil factors. In Guiyang City, we studied the species diversity of lithophytic mosses and the relationships between species and environmental factors. The results showed that: (1) There were 52 species of bryophytes in 26 genera and 13 families within the study area. The dominant families were Brachytheciaceae, Hypnaceae and Thuidiaceae. The dominant genera were Brachythecium, Hypnum, Eurhynchium, Thuidium, Anomodon and Plagiomnium; The dominant species were Eurohypnum leptothallum, Brachythecium salebrosum, Brachythecium pendulum etc. The number of family species and dominant family genera increased first and then decreased with the increase of altitude, and their distribution in elevation gradient III (1334-1515m) was the largest, with 8 families, 13 genera and 21 species. The elevation gradient I (970-1151m) was the least species distributed, with 5 families, 10 genera and 14 species. The dominant species with the largest number in each elevational gradient were Eurohypnum leptothallum, Brachythecium pendulum, Brachythecium salebrosum and Entodon prorepens; (2) There were five kinds of life forms in different elevation gradients, including Wefts, Turfs, Mat, Pendants and Tail. Among them, wefts and turfs appeared in all elevations, while a small amount of Pendants appeared in the area of elevational gradient I (970-1151m), and the most abundant life form was found in the range of elevational gradient III (1334-1515m); (3) Patrick richness index and Shannon-Wiener diversity index were highly significantly (p<0.01) positively correlated, both of which increased and then decreased with elevation, reaching a maximum at elevation gradient III (1334-1515m); The Simpson dominance index had a highly significant (p<0.01) negative correlation with the Patrick richness index and the Shannon-Wiener diversity index, which showed a decreasing and then increasing trend with increasing altitude; Pielou evenness index showed no discernible trend; (4) β diversity study revealed that while the similarity coefficient tended to decrease with increasing altitude, the species composition of bryophytes increased. The elevation gradient II (1151-1332m) and elevation gradient I (970-1151m) shared the most similarities, whereas elevation gradient III (1515-1694m) and elevation gradient I shared the least similarities (970-1151m). The findings can enrich the theory of the distribution pattern of lithophytic moss species diversity at distinct elevation gradients in karst regions, and serve a scientific and reasonable reference for restoring rocky desertification and protecting biodiversity there.
沿不同海拔梯度的物种多样性分布格局反映了物种的生物学和生态学特征、分布状况以及对环境的适应性。海拔是一个综合的生态因素，通过综合改变光照、温度、水分和土壤因素，影响植物群落中物种多样性的空间分布。在贵阳市，我们研究了石生藓类植物的物种多样性及其与环境因素的关系。结果表明：（1）研究区有藓类植物 52 种，隶属于 13 科 26 属。优势科为真藓科、金发藓科和石松科。优势属为真藓属、金发藓属、齿萼藓属、石松属、凤尾藓属和蔓藓属。优势种为粗肋凤尾藓、垂枝真藓、垂枝短月藓等。科、属的种数和优势科、属随海拔升高呈先增后减的变化趋势，在海拔梯度 III（1334-1515m）分布最多，有 8 科、13 属、21 种；海拔梯度 I（970-1151m）分布的种类最少，有 5 科、10 属、14 种。各海拔梯度中种数最多的优势种为粗肋凤尾藓、垂枝真藓、垂枝短月藓和密叶绢藓；（2）不同海拔梯度存在 5 种生活型，包括挺水型、密丛型、疏丛型、悬垂型和茎叶扭旋型。其中挺水型和密丛型在各海拔均有出现，少量悬垂型出现在海拔梯度 I（970-1151m），而茎叶扭旋型在海拔梯度 III（1334-1515m）最丰富；（3）Patrick 丰富度指数和 Shannon-Wiener 多样性指数呈极显著正相关（p<0.01），均随海拔升高先增后减，在海拔梯度 III（1334-1515m）达到最大值；Simpson 优势度指数与 Patrick 丰富度指数和 Shannon-Wiener 多样性指数呈极显著负相关，呈先减后增的变化趋势；Pielou 均匀度指数无明显变化趋势；（4）β多样性研究表明，随着海拔的升高，相似系数有下降的趋势，而藓类植物的物种组成则增加。海拔梯度 II（1151-1332m）和海拔梯度 I（970-1151m）的相似性系数最高，而海拔梯度 III（1515-1694m）与海拔梯度 I（970-1151m）的相似性系数最低。研究结果丰富了喀斯特地区不同海拔梯度石生藓类物种多样性分布格局的理论，为恢复石漠化和保护生物多样性提供了科学合理的参考。
