Eating from the wild: diversity of wild edible plants used by Tibetans in Shangri-la region, Yunnan, China

Wild edible plants (WEPs) refer to species that are harvested or collected from their wild natural habitats and used as food for human consumption [1‐3]. They provide staple food for indigenous people, serve as supplementary food for non-indigenous people and are one of the primary sources of cash income for poor communities [4‐6]. WEPs play an important role in ensuring food security and improve the nutrition in the diets of many people in developing countries [1, 5]. They are potential sources of species for domestication and provide valuable genetic traits for developing new crops through breeding and selection [7, 8].

Although domesticated plants are the main source of food and income for people in rural areas, they are not able to meet the annual food requirements [9‐11]. Thus, the collection and consumption of wild edible plants has been “a way of life” to supplement dietary requirements for many rural populations throughout the world [5, 12]. However, due to social change and acculturation processes, indigenous knowledge (or traditional knowledge) about the use of wild edible species is declining and even vanishing with modernization and increasing contacts with western lifestyles [13]. Meanwhile, the loss of traditional knowledge has also been recognized as one of the major factors that have negative effects on the conservation of biological diversity [14]. Thus, it is becoming urgent to document and revitalize traditional knowledge of WEPs to preserve genetic and cultural diversity [12, 15, 16]. China is renowned for its wide use of wild harvested resources in the human diet, and many studies have focused on wild edible plants [17‐28]. These ethnobotanical surveys not only play an important role in conserving traditional knowledge associated with WEPs, but also contribute to nutritional analysis of the most widely used species [1, 13]. Nutritional analyses may provide significant information for the utilization of those species that have the best nutritional values, thus helping to maintain dietary diversity and improve local food security [1, 2, 15].

Diqing Tibetan Autonomous Prefecture of Yunnan Province, commonly known as the Shangri-la region, belongs to the world-famous area called Three Parallel Rivers (Nujiang River, Lancang River and Jinsha River). It is the core of the eastern Himalayas and is regarded as a biodiversity hotspot [29]. Because of its complex topography and high diversity of climates, abundant plant and animal species are distributed in this area [30, 31]. Although Tibetans account for about 32.36% of the total population of the whole prefecture and have a relatively well-preserved and distinct cultural identity, there are also Lisu, Han, Naxi, Yi as well as Bai populations, among whom mutual cultural influences have existed for a long time [30, 31]. Furthermore, the diet of local Tibetan people differs somewhat from that of Tibetans in Xizang Autonomous Region. People living in the Tibetan Plateau have a limited range of food choices. The staple traditional diet includes Tsampa (made from hull-less barley), yak meat, mutton, buttered tea, sweet tea, barley wine and yogurt [32]. They seldom eat vegetables or fruits. On the other hand, because plant resources in Diqing Prefecture are more plentiful, and local Tibetans are influenced by other nationalities, they not only cultivate various crops, but also collect wild edible plants as supplementary food. These WEPs provide various microelements, and are also an important feature of local agrobiodiversity in which Tibetans have traditionally lived. However, the ecology of Diqing Tibetan Autonomous Prefecture is very fragile, and agrobiodiversity is being rapidly lost due to many natural and human caused factors [33‐35]. Many precious plant resources that may have potential for future sustainable development are vanishing before they have been discovered. The reduction of plant diversity also leads to the extinction of the associated indigenous knowledge [36]. Thus, documentation and evaluation of edible plants and relevant local knowledge is urgently needed. This work may guide proper conservation and sustainable utilization of those wild food plants and related indigenous knowledge.

Although there are several ethnobotanical studies concerning wild food plants used by ethnic minorities, such as Mongolians [18, 19], Miao in Hunan Province [21] and various ethnic groups in Yunnan Province [5, 17, 26‐28], to our knowledge, information on WEPs of the Shangri-la region used by Tibetans has not previously been documented. In order to fill this gap, ethnobotanical surveys were conducted throughout the prefecture. Scientific and local names, plant parts used, modes of preparation, seasonality patterns in collection and use, and commercialization possibilities of the WEPs are presented in this paper.

This paper is the first ethnobotanical study of wild food plants used by local Tibetans in Diqing Tibetan Autonomous Prefecture. As plant resources in this area are rather plentiful, and under the influence of other ethnic groups, local Tibetans not only cultivate various crops, but also collect wild edible plants as food. Our survey showed the diversity of WEPs and related indigenous knowledge in this area.

Different parts of plants are used by local people, and the most frequently used parts were fruits, young leaves and stems. These plants have different specific food uses, with leafy vegetable uses being most frequent, followed by fruit uses. WEPs provide food and nutrients to local communities, such as essential amino acids, various vitamins and minerals which are needed to keep healthy and enhance immunity against diseases and infections.

If properly harvested, WEPs could be the source of cash income for local people with low cash income because they are enjoyed by local people very much and often traded in markets. Furthermore, with the increased demand for green, healthy and safe food in modern society, wild food resources have attracted global interest because they are pollution-free and contain numerous important micronutrients and pharmacologically active substances. In order to properly utilize the wild food resources, we have some suggestions: 1) properly exploit and improve conservation and management of wild food plants; 2) focus on scientific research on wild food resources; 3) protect the natural environment and habitat for wild food plants.

In addition to food value, more than 50% of recorded plants have medicinal, ornamental, and cultural and other uses that are important in local Tibetan culture. Furthermore, some are crop wild relatives and could provide useful genes for crop improvement, which may have significant consequence on global food security. However, along with the development of economy, these multi-valued resources are threatened by human activities and natural causes, and associated traditional knowledge is eroding rapidly. Therefore, sustainable management of these resources as well as conserving biodiversity is of the utmost importance.

In a word, our ethnobotanical surveys provide data and information basis for conservation and sustainable utilization of local wild edible plants, and also contribute to preserve cultural and genetic diversity in Diqing Tibetan Autonomous Prefecture.