藏药“榜间”主流品种基原植物的潜在分布研究

Predicting the potential distribution of original plants of mainstream varieties of Tibetan medicine “Bangjian”

关键词:  “榜间”, 生态学调查, MaxEnt, ArcGIS, 潜在分布

Key words:  “Bangjian”, ecological investigation, MaxEnt, ArcGIS, potential distribution

摘要:

“榜间”为常用大宗藏药,但其生境特殊,生态位狭窄,部分品种资源量小,甚至濒危。为了明确“榜间”原植物的生态环境,预测生态适宜区分布,寻找影响适宜性分布的主要生态因子,该文以大花龙胆(Gentiana szechenyii)、高山龙胆(G. algida)、蓝玉簪龙胆(G. veitchiorum)、华丽龙胆(G. sino-ornata)和短柄龙胆(G. stipitata)五个主流品种为研究对象,采用生态学调查方法进行实地调查,以分析各品种的分布特征和生境特点,并应用MaxEnt模型和ArcGIS软件,预测潜在分布区。结果表明:(1)“榜间”五个主流品种的生长均需要较好的土壤肥力条件,大花龙胆和短柄龙胆仅分布于草本层低矮的草甸或草甸灌丛,其余品种因茎有较大的伸长幅度,生态幅较广。(2)海拔是影响“榜间”五个主流品种分布的限制因子,对大花龙胆、高山龙胆、蓝玉簪龙胆、华丽龙胆和短柄龙胆生境适宜性的贡献率分别为56.5%、39.6%、49.4%、48.1%和44.2%,高山龙胆主要分布在海拔1 500 m以上的地区,而另外四个品种主要分布于海拔2 600 m以上的地区。(3)藏药“榜间”五个主流品种生长适宜区主要集中在四川、青海、云南、甘肃和西藏五省(区),但不同基原植物在各省(区)的分布面积和空间格局有差异,大花龙胆和高山龙胆的最适分布区集中在四川、甘肃、青海、西藏四省(区)交界处,后者在新疆地区也有最适分布区; 蓝玉簪龙胆最适生长区位于四川中部、四川北部接壤青海及甘肃处、四川西南部接壤云南处、西藏东部; 华丽龙胆与短柄龙胆最适生长区主要位于四川、青海、甘肃的交界地带,适生区范围较蓝玉簪龙胆狭窄。研究结果与实际调查结果基本相符,可以为“榜间”野生资源的保护及相关植物的人工栽培提供科学依据。

Abstract:

“Bangjian” is a commonly used in Tibetan medicine, but its habitat is special, the niche is narrow, the resources of some varieties are small, even endangered. In order to define the ecological environment, predict the distribution of ecological suitable areas, and find out the main ecological factors affecting the distribution of ecological suitability of original plants of mainstream varieties of Tibetan medicine “Bangjian”, we took five mainstream varieties as the research object, including Gentiana szechenyii, G. algida, G. veitchiorum, G. sino-ornata, G. stipitata, used ecological survey methods to conduct field surveys to analyze the distribution characteristics and habitat characteristics of each species, and applied the MaxEnt model and ArcGIS software to predict potential distribution areas. The results were as follows:(1)The growth of the five mainstream varieties of “Bangjian” required good soil fertility conditions. G. szechenyii and G. stipitata were only distributed in low grasses meadow or meadow shrubs, and the other varieties had a wide range of ecology because of the large elongation of the stem.(2)Altitude was the limiting factor that affected the distribution of the five mainstream varieties of “Bangjian”, and the contribution rates to the habitat suitability of G. szechenyii, G. algida, G. veitchiorum, G. sino-ornata, G. stipitata were 56.5%, 39.6%, 49.4%, 48.1%, 44.2%, respectively. G. algida was mainly distributed in the area with an altitude of more than 1 500 m, while the other were mainly distributed in the area with an altitude of more than 2 600 m.(3)The five mainstream varieties mainly concentrated in Sichuan, Qinghai, Yunnan, Gansu and Tibet, but the distribution areas and spatial patterns of different species were different in each province(region). The optimal distribution area of G. szechenyii and G. algida was similar, concentrated at the junction of Sichuan, Gansu, Qinghai and Tibet, and the latter also had the most suitable distribution area in Xinjiang; The most suitable areas for G. veitchiorum were located in central Sichuan, northern Sichuan bordering Qinghai and Gansu, southwestern Sichuan bordering Yunnan, and eastern Tibet; G. sino-ornata was similar to G. stipitata, whose most suitable area was mainly located at the junction of Sichuan, Qinghai, and Gansu. Both of them were narrower than that of G. veitchiorum. It should be noted that G. szechenyii and G. algida were aggregated populations of plaque distribution. The ecological suitability distribution result of each species were basically consistent with the actual investigation results, which provides a basis for the protection of wild resources and artificial cultivation of related plants.