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This study focuses on the accumulated indigenous knowledge of the Yao ethnic minority in Bac Kan Province of Vietnam. Through centuries of observation and experimentation, the Yao people have developed complex farming systems, cultural practices, and a knowledge base well-suited to their environments. Data for this study was collected through surveys, interviews, and focus group discussions to gather indigenous knowledge on native crop varieties and animal breeds, weather forecasting, and the timing and location of cultivation prac- tices. In so doing, this study documents unique examples of how indigenous knowledge is being used alone and blended with scientific knowledge to make accurate decisions and help local communities adapt to climate change. The case of the Yao people in northern Vietnam supports the argument that if indigenous knowledge were better integrated into adaptation planning and policies, its conservation and application would enhance resiliency to climate change in indigenous communities and beyond.

1. Introduction 

Indigenous knowledge (IK) is commonly acknowledged as an un- tapped resource in the process of local and community development (World Bank, 1998). Although relatively new to climate science, this knowledge has been long recognized as a key source of insight into disciplines such as agro-forestry, traditional medicine, biodiversity conservation, resource management, impact assessment, and natural disaster preparedness and response (Balemie, 2011; Dey and Sarkar, 2011; Walsh et al., 2013; Lakshmi et al., 2014; Cuc, 2015; Armatas et al., 2016). Resilience in the face of change is embedded in this know- how, and manifested in more diversified resources and secured liveli- hoods, social institutions and networks, and cultural values and atti- tudes (Fikret et al., 2000; Anthony et al., 2007; Pareek and Trivedi, 2011; Bonnin and Turner, 2012; Naess, 2013; Delisle and Turner, 2016; Turner et al., 2015). IK could comprise a more vital component of global knowledge on development issues, contributing problem-solving strategies for local, and especially economically disadvantaged, com- munities (World Bank, 1998). Scholars in the knowledge economy are exploring these ideas with the expectation that IK contains important messages employable to overcoming current shortcomings in 

agriculture and environmental sustainability (Fikret et al., 2000). The erosion of IK undermines the future adaptive capacity of local com- munities, particularly those situated in the Global South (Ford and Smit, 2004; Alexander et al., 2011). If local knowledge were better incorporated into adaptation planning by policy makers, its conserva- tion and application would enhance resiliency to climate change in indigenous communities.

Although the relevance of IK in the face of future climate change remains contested, its role has received increasing interest in adapta- tion studies (Ford et al., 2007; Armatas et al., 2016). Adaptation in the context of climate change consists of adjustments in practices, pro- cesses, or structures performed in response to the actuality or threat of long-term climate change and understood to be an evolving process (Adger et al., 2007). Thus, adaptation means both recovery and change. For example, after a natural disaster, affected communities recover from the impact, that is they return to some pre-existing state and/or they may adjust and make minor or major changes to accommodate the impact. Therefore, adaptation is a long-term process of learning and adjusting. In this paper, adaptation is understood as a set of strategies and actions taken in reaction to or in anticipation of change by people to enhance or maintain their well-being; where well-being is used as the 

surrogate of community resilience from a local perspective. Such stra- tegies could include the adoption of efficient environmental resource management practices such as the planting of early maturing crops, adoption of hardy varieties, or the selective keeping of livestock in areas where rainfall has declined. They also include the use of tech- nological products that enable the individual to function under the “new” conditions (Anthony et al., 2007).

Indigenous knowledge (IK) refers to the unique know-how of a so- ciety or culture, and encompasses the cultural traditions, values, beliefs, and worldviews of local people (Agrawal, 1995). IK has been defined as institutionalized local knowledge that has been built upon and passed from one generation to the other by word-of-mouth (Osunade, 1994). It provides the basis for local-level decision-making in many rural com- munities. Notably, as indicated by Rautela and Karki (2015), the in- tegration of IK in disaster risk reduction has revealed its significant actual and potential contributions in the preparation, response, and post- natural disaster recovery processes. In geographical context of Vietnam, local or indigenous knowledge refers to the activities of the country's many ethnic minority communities. This knowledge is formed, accumulated, and perfected through the production process of the whole community and passed orally from generation to generation (Tý and Cúc, 1998).

In the case of climate change, indigenous observation is on the local level and resultantly communicates change from the point of view of the geographically proximate. Observations may relate to changes in the predictability of weather or the increased frequency of extreme weather events. These observations complement global science (Dyanna and Berkes, 2001). In example, global circulation models provide a powerful tool for climate change research, but are limited in their explanatory power, especially at local level (Berkes, 2007). Community-based monitoring and indigenous observations are sig- nificant in this regard because they provide insights into local impacts and adaptations (Fikret et al., 2000). In effect, as climate change pre- sents itself in weather extremes and variability, IK provides a mean- ingful local expression of this manifestation.

According to Chanza and Wit (2016), the elements of IK, for ex- ample, participation, flexibility, inclusion, and autonomy are a function of climate governance. For instance, as a response to climatic events such as floods and drought, users of IK are often flexible to actively choose available coping and adaptive options for climate proofing. Examples of such adaptation strategies based on local knowledge have been identified by various authors for predicting hydro-meteorological and catastrophic threats through environmental observations (Bright et al., 2013; Mavhura et al., 2013; Hiwasaki et al., 2014; Armatas et al., 2016). Research is gradually recognizing the importance of IK systems in developmental studies. Climate change mitigation and adaptation projects can learn from the experiences of other developmental projects by further recognizing the value of indigenous knowledge systems (Anthony et al., 2007). As such, incorporating it into climate change adaptation strategies would add value to the sustainable development of and help to create more ethical economies. Indigenous knowledge systems provide mechanisms for participatory approaches. A major requirement for the sustainability of any project is that the local po- pulation must be seen as partners in the project, with joint ownership (Anthony et al., 2007).

Vietnam is predominately an agricultural country, and is classified as one that will be most severely affected by climate change (Dasgupta et al., 2007). The erratic seasonal fluctuations of temperature, rainfall, and humidity often lead to adverse impacts on human health as the increase in the occurrence of disease and natural disasters stress food production and food security (McSweeney et al., 2010). Nelson and Kokic (2004) state that climate change is now having a pronounced impact on all aspects of rural life, including income and food security, and found an attributed intensified rate of environmental degradation. In turn, this has negative upstream effects on the national economy. In recent studies on climate change in Vietnam, it is stated that it has intensified the effects of disasters, especially on poorer and rural po- pulations in mountainous areas and along the coastal regions (Shaw, 2006; Bangalore et al., 2016; Delisle and Turner, 2016; Vu et al., 2017). Consequently, it is the ethnic minorities of Vietnam, who largely reside in these peripheral areas, who are particularly sensitive and vulnerable to its impacts and are more likely to face rapid variations in tempera- ture, weather patterns, and extreme weather events (Son, 2013; Wildcat, 2013; Valentino et al., 2016; William et al., 2016; and Ella et al., 2017).

The country of Vietnam has 54 different ethnic groups, many of who have lived for years in the northern mountainous region of the country and have their own cultural traditions and unique agricultural prac- tices. Many of these mountainous communities rely largely on their experience, traditional practices, and knowledge drawn from environ- mental observations (Son, 2013; Van Dien and Van, 2014). However, the accrued local knowledge of these indigenous groups is being lost at rapid rates. While appreciating that IK evolves over time, it currently tends to be more recognized and used among the elders in Vietnamese ethnic minority communities. Younger people express little interest in conserving traditional knowledge and skills, and tend to be more in- terested in scientific knowledge and modern technologies. The desire for increased earning potential also results in fewer youth remaining involved in farming, and urban migration is the norm. As a result, land- based skills among ethnic minority populations has eroded. For ex- ample, Son (2013) found few ethnic minority youths who knew which plants or herbs could be applied as medicine for common injuries or illnesses. This erosion of traditional and local knowledge undermines the future adaptive capacity of these communities.

With a population of 751,067 people accounting for < 1% of the total population of Vietnam (according to the 2009 Census of Population and Housing in Vietnam released by the General Statistics Office of Vietnam (2009)), the Yao or Dao ethnic minority ranks ninth in size among ethnic groups in the country. They reside largely in the northern mountain provinces of Ha Giang, Tuyen Quang, Cao Bang, Bac Kan, Lang Son, Lai Chau, Son La, Lao Cai, and Yen Bai. Many Yao people speak a language belonging to the Hmong-Dao family as a first language (Dien, 2002). Living in middle altitudes, between 400 and 600 m above sea level, the Yao people reside at higher elevations than the Tay, but not as high as the Hmong. As a result of their local terrain, the Yao people have developed their own unique indigenous systems of terraced farming, which along with weaving and silver craft making, comprise their main source of income. Farmers grow wet rice on ter- raced fields to provide a primary source of food (Son, 2013). Little is known about their vulnerability and adaptation to climate change.

This study gathered the IK of the Yao people in one Commune in Bac Kan Province on native crop varieties and animal breeds, their experi- ences with and understanding of weather prediction, and how they organize the timing and location of specific cultivation practices. The IK that survives continues to evolve to match local conditions, and helps to build the capacity of households and communities to adapt to changing situations. The main objective of this study is to provide insights into how the IK of the Yao people is used in climate change adaptation, and how this might promote the integration of IK into climate change adaptation plans and strategies on the local, regional, and national, and international scales. 

2. Description of study area 

Phuc Loc is an economically-disadvantaged and remote commune of 3150 people in Ba Be District, 50 km from the center of Bac Kan Province (Fig. 1). The commune has 19 villages, 12 of which are mountainous and difficult to access, and only 10 of the 19 villages are equipped with electricity. Due to the complex terrain, mainly upland hills, the area has a number of meso- and micro-climates. The agri- cultural fields and livestock are typically proximate to smaller streams, meaning production is often affected by natural disasters and variable 

Fig. 1. Study location.

Source: The Authors.

extreme local weather events including floods, hail, landslides, intense cold, and frequent droughts. Fig. 1 shows the location of Phuc Loc Commune and Ba Be District within the context of northern Vietnam.

The climate in the north of Vietnam is divided into 4 seasons: Spring (February to April), summer (May to July), autumn (August to October), and winter (November to January of the following year). Precipitation is highest in the summer meaning it is typically referred to as the “rainy season”. During this season, the entire mountainous region experiences heavy rains, flooding, and landslides. In contrast, pre- cipitation is lowest in the winter and as such it is referred to as the “dry season”. The area of Phuc Loc Commune is over 50% forest land. Only 25% of the land is under cultivation (See Table 1).

The Phuc Loc Commune villages of Phieng Chi and Na Ma were selected as the study sites. There are 53 households in Phieng Chi Village and 37 households in Na Ma. Everyone residing in these villages are members of the Yao ethnic minority. Both villages have high rates of poverty, with 88.46% and 75% of surveyed households respectively. Agriculture is the main source of income in both locations. This is summarized in Table 2. 

3. Methodology

 A number of previous studies exploring the IK of ethnic minorities in response to climate change have employed case studies as the primary means of data collection (e.g., Grenier, 1998; Rivaldo et al., 2012). This study also used a case study approach to examine the vulnerability and capacity of the Yao people in responding to climate change. This combination of approaches was used to: (1) identify the climate in- duced risks that Yao communities have already experienced; (2) char- acterize how Yao communities experience and manage climatic risks using IK; (3) identify opportunities for and constraints to adapting to climate variability and change when using IK; and (4) identify entry points for adaptation policy.

Data collection for this study combined surveys, interviews, focus group discussions (FGDs), and participant observation to generate in- formation, triangulate insights, and compile an accurate and detailed

Table 1

Areas of different land-use in Phuc Loc Commune.

Source: Unpublished Report of Phuc Loc Commune, Vietnam.

Land use                                     Area (ha)                           Percentage

Forest land



Agriculture land



Aquaculture land



Residential land






Table 2

General information of study areas. Source: Fieldwork, 2017. 


Phieng Chi village

Na Ma village

Number of households



Poverty rate (%)



Main livelihood



 picture of the dynamics of using IK for climate change adaptation. This was further supported by the insights and opinions of local and regional decision-makers, resource managers, scientists, published and un- published literature, and other available sources of information. Overall, data collection can be divided into the following six general- ized steps.

 3.1.   Preparation for eldwork

 Considerable work prior to entering the field helped to establish a network of collaborators at the at local, regional, national, and inter- national levels that helped to strengthen knowledge sharing and de- velop research outlets for academic and advocacy purposes. This in- cluded government offices, non-government stakeholders, and research institutions active at the study site. During this process, the actual study area was identified based on the pre-determined criteria including that it be a village densely populated by Yao people, affected by climate induced events such as drought and cold spells, and one whose popu- lation was heavily involved in non-timber related agricultural activities.

Two villages of Phuc Loc commune, Ba Be district, Bac Kan Province of Vietnam (See Fig. 1) were selected as field sites. Bac Kan Province is situated in the north-eastern part of northern Vietnam and Ba Be is one of its poorest districts. Covering a total area of 67,809 ha, the popula- tion consists of about 47,000 people living in 16 communes. Approxi- mately 80% of the population belong to ethnic minority groups, in- cluding the Tay, Yao, Hmong, and Nung.

3.2.   Interviews: Phase 1 

Ten in-depth interviews were conducted with local representatives of varying social and economic groups in order to obtain initial im- pressions of their experiences with natural disasters, weather extremes,

                                                                                                                                                    climate change, and the attributed adaptation strategies. It also pro-

Forest land



Agriculture land



Aquaculture land



Residential land








vided base information on social, economic, educational, and en- vironmental conditions of the intended study areas. On the basis of the results from these interviews, a more complex interview schedule was developed. This schedule was tested and continuously improved  throughout the subsequent interview process. Finally, as the primary language of many Yao people is not Vietnamese, support staff to assist with potential linguistic difficulties were also identified, typically the head of the local village. As research progressed into later stages, we ultimately found that most respondents were able to communicate ef- fectively in Vietnamese.

3.3.   Household survey

 A baseline survey was carried out in the two villages to become better acquainted with residents and their situational context. The survey beneficially helped establish contacts with potential respondents while constructing both a sampling framework of key themes and a database of information on which to build subsequent research. A questionnaire was also used to facilitate the collection of basic data on the organization of local households. These included the domestic household economy, agricultural production systems, and membership in village institutions and organizations. Questions were also included inquiring how households and communities have been able to adapt to climate events through, in example, food sharing, (in-) formal net- works, and the support of local institutions. The households for the baseline survey were chosen randomly. Later, a sub-sample of 30 households (16 households in Phieng Chi Village and 14 households in  Na Ma) were selected based on socio-economic indicators such as housing conditions and location of the household in the village. These respondents were interviewed as part of the second phase of interviews listed below in number 5. 

3.4.  Focus group discussions

 FGDs were organized to take advantage of village group dynamics to both acquire information and also cross-check and clarify informa- tion collected by other means. Participants were selected to include both genders and every economic standing. The first FGD groups were segregated by gender to address cultural norms where women may have found it difficult to express themselves in the presence of their husbands or elderly male villagers. The second set of FGDs reintegrated respondents to illicit their observations on similar themes with inter- views such as impacts of climate change on the Yao people, the use of IK by the community, and how IK was being combined with scientific knowledge. Each FGD session was comprised of 5 discussants, ranging in age from 35 to 60 years old. The agreed upon opinions help to form and situate the conclusions of this article.

3.5.   Interviews: Phase 2

 The most important method for primary data collection for this study was the qualitative interview. Experienced farmers knowledge- able of the area were considered eligible to participate. In each village,

20 experienced farmers were interviewed. Additionally, two staff members of the Department of Agricultural Extension of Ba Be District and Phuc Loc Commune were interviewed. A total of 42 key re- spondents were selected taking into consideration their age, gender, and employment in the village. Key respondents included an IK scien- tist, district and commune agricultural extension and development of- ficers, village head, women's union head, and selected elderly with standing peerage. Interview questions focused on assessing the impacts of climate change on the Yao people, the use of IK by the community, how IK was being combined with scientific knowledge, and the iden- tification of entry points for IK promotion. All respondents who were asked to participate agreed. Upon the completion of fieldwork, inter- view data was processed using SPSS and qualitative information ana- lysis for reporting and documentation.

3.6.   Participant observation

 Throughout fieldwork, participant observation was used to facilitate 

Table 3

Social-economic background of respondents. Source: Fieldwork, 2017.


Gender Male




















Above 60



Marriage status












No formal education



Primary school





Item                                         Number (x = 30)              Percentage (%)

amiable rapport with respondents, ease the sharing of information on sensitive topics, and gain insights into daily activities and perceptions. Observations and insights were further clarified during the interview process. Participant observation also permitted the first-hand observa- tion of the impacts of climate hazards on local livelihoods, and the practices of the Yao people in response.

 4. Results 

4.1.   Household survey

 A survey was designed to gather basic social-economic data on the residents of the villages. It included open- and closed-ended questions. 30 people completed the survey; 16 from Phieng Chi Village and 14 from Na Ma Village. Notable is the lack of even a secondary school education of most respondents and the low household economic status. However, the respondents were able to understand, speak, or write in Vietnamese (Table 3).

 4.2.   Climate vulnerability and impacts

 Drought, flood, and cold spells were found to be common climate risks in the mountainous provinces. As reported by the Department of Agricultural Extension of Ba Be District (Ba Be Statistics Office, 2017), droughts have increased in frequency and severity over the last fifteen years. Drought affects agricultural production, animal husbandry, and local infrastructure. Severe cold impacts the livelihoods of people as it can result in a loss of livestock and the failure of crops. Tropical cy- clones have a high level of impact on the whole community, damaging crops, infrastructure, and housing. In addition, the area is also affected by landslides, periods of extreme heat, and flash floods. Of particular importance has been the increase in temperature over the last 50 years, as this both intensifies and expands the variety of pest and disease pressures in local farming (See Fig. 2).

Table 4 summarizes some of the more extreme weather-related oc- currences in the study area over the last 20 years. An increased in- tensity, frequency, and duration of drought, flood, and cold spells were mentioned most by respondents as having adversely affected their li- velihoods.

It is also important to note that when crops are destroyed, farmers are unable to save the seeds necessary for planting in the subsequent year. This exacerbates the financial loss by adding the requirement of 

 Fig. 2.Temperature variation of Bac Kan Province over the last 50 years. Source: Bac Kan Meteorology and Hydrology Department (2013).

 an expensive outlay of capital needed to invest in future planting ma- terials.

4.3.   Adaptation strategies

4.3.1.    Using native crops and animal breeds

A number of varieties of native crops and animal breeds were uti- lized in the study area. Native crops and animal breeds fare well under local conditions. Table 5 below shows native crop varieties and animal breeds cultivated by the Yao people in the villages of Phieng Chi and Na Ma.

4.3.2.    Local experience in forecasting weather

Local skills of the Yao people in predicting the weather have evolved through observation and experience, and have been trans- mitted to subsequent generations though oral tradition. Due to their relative isolation, limited access to the availability of scientific knowl- edge and information, and cultural preferences, many mountain com- munities in northern Vietnam still rely largely on their experiences, traditional practices, and knowledge based out of environmental ob- servation.

The Yao people use several indicators to predict the onset of rainfall as well as changes in weather patterns. Weather forecasting by farmers was found to be largely based on interpreting the behavioral patterns of animals and birds, observing phonological changes associated with plant and tree species, examining phenomena in the troposphere and night sky, and most often some combination of these indicators learned over time. These they described as “personal experience”, and are used to forecast weather and adjust their routine activities and farming practices. Some of the weather forecasting tools related to flora and fauna are documented in Table 6. Today, local people can rely more on technological devices such as television or/and radio for weather forecasts, but they still see the efficiency and validity of natural 

indicators such as animal behavior or plant phenology. They also noted the unpredictability of climate related events such as rain or floods in terms of timing and magnitude. For example, based on their local ex- perience, heavy rain and thus flood ends in August, but recently it may extend through September. Stated differently, this unpredictability sometimes results in crop loss as agricultural decisions are often derived from local experience.

Some of these related to changes in the conditions of the tropo- sphere and night sky are documented in Table 7. Local people have used these indicators for years and have not seen major changes over time.

4.3.3.    Using local cultivation practices

In addition to forecasting the weather, members of the Yao ethnic group in Bac Kan Province also have valuable experience in forecasting the seasonal calendar for agricultural and forestry crops. Most of these experiences are based on observing the flowering period of plants (See Table 8). These observations have been used for a long time and have not changed considerably over time.

Additionally, respondents explained that by examining the shape and brightness of the moon they can predict the weather for the next cropping season. For example, if the moon on August 15th in the lunar calendar is neither too dark nor too bright then a good rice crop season in May of the following year can be expected. Otherwise, it will be a difficult season (e.g., caused by a lack of rain or outbreak of pests). Similarly, members of local communities also use indigenous knowl- edge to select arable land and determine optimal cropping rotations. They plant native varieties of arrowroot in newly cultivated upland fields, as the soil is known to be more nutritious and suitable for growth. Furthermore, it is widely understood that after 2–3 years that same field should be converted to the cultivation of maize. Another practice used locally is the burning of all crop residues including any straw or grass on the field before the start of a new cropping season. Respondents noted that this practice both reduced pathogens and also that the ashes advantageously provide additional nutrients to the soil. It should be noted that local farmers have little formal training in disease prevention in cropping, and rarely use commercially available chemical pesticides.

5. Discussion

5.1.   The IK of the Yao people at the two communities in Bac Kan Province of Vietnam

This study collected IK from two communities populated by Yao ethnic minorities in a rural part of the north of Vietnam. It found a largely impoverished and informally educated population facing con- siderable changes in climate. Despite this, their utilization of IK pro- vides their communities with both agency and adaptability. In example, despite government incentives for the communities to produce hybrid crops, a number of native varieties and animal breeds remain culti- vated/raised in the study area. Native crops and animal breeds are well 

Table 4

Timeline of the extreme weather events in the study area. Source: Archival Research and Fieldwork, 2017.


  • A long dry spell lasted for 3 consecutive months from January to March that obstructed the cultivation plans of local farmers.


  • A number of floods occurred which covered fields and destroyed crops in July.


  • Severe cold killed livestock in a number of villages during winter.


  • Landslides and flash floods caused by heavy rain from June to July covered fields and destroyed crops.


  • Landslides and flash floods covered fields, destroyed crops, and killed livestock from August to September.


  • Incidents of storms, severe landslides, and a long dry spell limited water availablity for summer irrigation (May–July).


  • In July, flash floods occurred that covered fields and destroyed crops.


  • Prolonged heat occurred in May and June with daytime temperatures of 35–40 °C. This resulted in a shortage of water for irrigation.


  • A long drought meant no water for irrigation during June and July.


  • Storms, floods, and landslides were recorded causing extensive crop damage in a number of locations from July to September.


Native crops and animal breeds in the study area. Source: Fieldwork, 2017.

Native type

Name in the local Iu Mien dialect

Features as noted by respondents


khu Ban

Planting is in the summer and harvested in autumn. The yield and quality is equivalent to the hybrid rice variety Bao Thai. The color of the rice when ripe is brown.



The variety has good drought tolerance. It is more resistant to local pest pressures, cold hardy, and suitable for highland






The leaves and stems are smaller than and the yield one-third less than the newer hybrid varieties.



Planting season is in February to March, with the harvest in November.




me zhàngmp

Native arrowroot is better quality and has a higher proportion of starch than hybrid varieties.

The stalk is taller than most other varieties grown.



It takes 4 months from planting to harvest.



It has a low yield of only 1/3 that of the newer hybrid varieties.



It is high quality and considered more flavorful than other varieties.



It is known to store easily, is less susceptible to termite damage, and can be preserved longer (6 months to a year) than


Green soybean



hybrid maize.

It has a short growing period.



When ripe, the pods do not open, and the seeds are small and green.



Yellow soybean



It has a low productivity of only 0.8–1.1 ton/ha. It has good tolerance to drought.

It shares similar color characteristics and particle size with soybean DT84 (i.e., the hybrid commonly grown in Vietnam).


Glutinous rice



It is drought tolerant and has an average yield.

It is a high quality rice, but has low productivity.



It is drought-resistant, and can be grown on the hills as an upland crop.


Black chicken



Tall stems mean the crop is susceptible to wind damage, and it has a long growing period.

The average weight of 2 kg is smaller than that of hybrid chickens.



They suffer from less disease, are cold hardy, and produce a high quality of meat.

Black pig


They have black hair, a long muzzle, and reach a maximum weight of around 40 kg.



They suffer from less disease, are cold hardy, are easy to raise, and produce a high quality of meat.

 known to Yao farmers, thrive under local conditions, and they continue to match dietary preferences. Similarly, IK gained through experience permits the adjusting and planning for crop production to best suit local climate conditions. Farmers do not have to rely on government guide- lines which may not be appropriate to the complex topography and diverse microclimates of this mountainous region.

The knowledge of traditional forecasting has also been adapted from and evolved with local conditions. Yao people make physical observa- tions on bird behavior, the flowering or flushing of specific tree and plant species, and the patterns and movement of clouds and objects in the night sky. Within the study area, these forecasting methods were found to comprise the basis for farmer decision-making during the cropping season. In turn, this reduces vulnerability by enabling the farmers to make a variety of adaptations including adjusting the timing of their crop plantings and harvesting or changing the types of crops they plant. This is an example of adaptation in agricultural production by local farmers within the context of climate change.

Today, Yao communities have better access to weather information and forecasts from government services such as television and radio. Many households now appreciate the importance of weather forecasts and early warnings from local authorities or through the media. They make use of these services and do not have to rely only on their 

Table 6

Using flora and fauna as indicators for weather changes. Source: Fieldwork, 2017.

Changes in weather Flora as indicator Fauna as indicator
Sunny weather  

If black magpie-robins and hawks are seen flying upwardly and singing when the rain appears to have stopped, the rain is said to be finished and it will become sunny.


When bamboo shoots grow straight out of the bamboo grove, windstorms can be predicted. If the bamboo shoots thrive in the middle of the bushes that year, a great storm will occur.


When going into the forest, if the leaves of the Bo De tree are observed to be turned upside down and colored white, then rain is imminent.

If mushrooms are seen in the forest (name in the local Iu Mien dialect: chiubìúng), the weather will be more humid, or it will rain heavily after three days.

If the Moc Mat tree is seen to bear more than a typical amount of fruit, annual precipitation rates will be high.

When going into the forest, if the leaves of the Bo De tree are observed to be turned upside down and colored white, then rain is imminent.

If mushrooms are seen in the forest (name in the local Iu Mien dialect: chiubìúng), the weather will be more humid, or it will rain heavily after three days.

If the Moc Mat tree is seen to bear more than a typical amount of fruit, annual precipitation rates will be high.


If the “Tuhu” tree (i.e., a native variety of litchi) is seen to bear more than a typical amount of fruit, droughts over the next year are to be expected.

Flood A great deal is learned by examining moss in local streams and ponds (name for moss in the local Iu Mien dialect: thìnhtòi). If the moss is floating in the stream, rain in approximately five days can be expected. If yellow moss is seen on the surface of a pond, then rain will occur within the next day or two

If crabs (name in the local Iu Mien dialect: gung guy) from the local stream are seen crawling on the road, it is about to flood.

Cold spell  

If the hives of bees are low, one can expect a period of prolonged coldertemperatures.

 Table 7

Troposphere and sky changes as indicator for weather phenomena. Source: Fieldwork, 2017.

Weather phenomena Descriptions
Hot weather

If the sky is seen to be with clouds shaped like fish scales arranged in stories and moving in a south to north direction, it can be predicted that in around two days there will be a prolonged period of sun until the end of the month. When the moon is seen with glowing white rings, the weather will be hot and dry in several days. 

Rain/Storm If the cloud layer is moving in a north to south direction, after two days there will be heavy rain. When the sky is red at night, there will be heavy rain or storm.

Table 8

Local cultivation practices. Source: Fieldwork, 2017.

Practices Time/Observation Description
Spring rice crop When forest peach flowers are blooming

As explained by respondents, when the flowers are blooming, the weather is warmer and wetter, so it is possible to transplant rice without fear of crop loss.

Summer-fall rice crop When the forest peach fruit is ripe

During the period when peaches ripen it typically rains, so sufficient water should be available to transplant paddy rice.

Maize cultivation When plums blossom

The plum flowers blossom during the spring rains. This implies that the soil is likely moist, creating more suitable conditions for growing maize as there is less fear of draught.


When the neem tree is flowering, it is time to sow upland rice.

Local Yao people look at this flowering to determine the optimal time for sowing. In many cases, they do not follow the government guidelines/instructions for sowing times with upland rice. Note that government instruction does not distinguish between hybrid and native varieties and only provides general procedural instructions.

Intercropping   Sweet potatoes are intercropped with arrowroot for increasing the coverage of soils and using leaves for animal feed.

personal experiences and knowledge. While the elderly tend to possess more indigenous knowledge and experience than the young, IK is not becoming less important for Yao people in climate change adaptation.

 5.2.   Future limitations of using local knowledge for climate change adaptation

 Traditional coping and adaptation strategies as employed by the Yao people can only prepare communities for some perceived risks, not necessarily for the uncertain and possibly different conditions brought by a rapidly changing climate. As a result, climate change has the po- tential to critically alter the relevance and appropriateness of at least some of their traditional knowledge. For example, native crop varieties and the IK attributed to their successful cultivation may be suited to current local climatic conditions, but unable to adapt well in future and rapidly changing climate regimes. Furthermore, natural signals that triggered activities in the past are now less reliable. For example, due to higher unpredictability of weather and climate events, some local forecasts such as timing of flood or rain are less precise.

As the climate becomes warmer in the tropics, the rainy season can come earlier and/or later than usual (Macchi et al., 2008). As a con- sequence, indigenous people's observations and weather forecasting systems in the future may become less meaningful or even misguide them in their decisions. In this way, communities might be well adapted to their current climate, but less able to adapt to climate change as existing knowledge is typically based on the past experiences rather than coping with extreme events. For example, in the case study area of this article, the severity of the cold spells in 2008 and 2011 was outside the social memory of most households, who lacked the knowledge and experience to mitigate their adverse effects. While a cold spell with the magnitude and intensity of that in 2008 had not occurred for almost 50 years, events of this magnitude are now predicted to become more regular. This is an example where knowledge of the past may not help communities to cope with an extreme event. Such extreme events are predicted to be more common in the context of climate change, and highlight the importance of combining local and scientific knowledge in climate change adaptation. Government support to enhance local communities' access to relevant scientific information and technology, such as through early warning systems, may help reduce indigenous people's vulnerability to climate change.

 5.3.   Combining dierent types of knowledge

This study also found that the Yao people occasionally blended IK with information provided by extension agents, research institutes, and government. For example, television and radio weather forecasts were combined with observations of animal behavior and changes in flora to develop more precise weather predications suited to their local condi- tions. Farmers were also observed using drought- and/or cold-tolerant hybrid crops bred by research institutes. In addition to the native ar- rowroot species, members of the villages planted arrowroot DR1, which is provided by the government as it is high yielding and widely adap- table to many soil types and soil nutrition levels. Additionally, farmers were found to be using both hybrid maize and native maize selectively to suite different land types. Hybrid maize was grown where water was accessible, and native maize in the upper hills as it is more drought tolerant. Yao farmers were found cultivating not only native glutinous (i.e., sticky) rice varieties, but the hybrid varieties promoted by gov- ernment to manage issues of food security. On one hand, the continued resistance of the Yao people to the wholesale adoption of government recommended hybrid varieties speaks to the maintenance of autonomy (Bonnin and Turner, 2012). On the other, it also speaks to a larger collaborative potential.

As argued by Berkes (2007), scientific knowledge and IK need not be mutually exclusive and can be amalgamated. Combining indigenous and scientific knowledge on social-ecological systems is crucial for understanding the resilience of those systems (Fikret et al., 2000). Bringing different kinds of knowledge together and focusing on the complementarity of these knowledge systems helps increase the capa- city to learn (Berkes, 2007; Bohensky and Maru, 2011).

6. Conclusions 

Indigenous knowledge (IK) has the potential to further the processes of developing and promoting sustainable local and community devel- opment. Many communities globally, especially those populated by  indigenous people, already have the contextualized and relevant knowledge for addressing problems including many climate risks. This study focused on the Yao people, an ethnic minority who typically in- habit the rocky and higher mountainous regions in the north of Vietnam.

This study found that the diversity of native plants and animals in the Yao IK system contributes to the improvement and maintenance of ecosystem services, and improves their adaptability to climate change. Native plant varieties and animal breeds tend to be more resistant to diseases, less susceptible to pathogens than newer hybrid varieties, and do not require high investment for intensive cultivation. As a result, they are not only more suitable to local conditions, but also more available to the economically-disadvantaged communities. Furthermore, their cultivation prevents the loss of valuable plant ge- netic materials with high disease resistance and helps to maintain the biodiversity of the planet.

This study also found that Yao communities in Bac Kan Province either ignore government suggestions in favor of local IK (e.g., using indicators such as the flowering of the neem tree to decide sowing dates for upland rice) or combine IK with new scientific technologies to help alleviate the effects of climate change on their communities. In the case of the latter, this combination of approaches contributes to commu- nities being more capable in effectively responding to current changes in climate. Working within this collaborative framework, governments should seek to support this dualistic problem solving approach and enhance access of local communities to relevant scientific information that both supports them and accommodates their knowledge. Within our study area for example, an early warning system to notify residents of imminent temperature drops would greatly reduce vulnerability. Building on existing local and traditional knowledge about managing climate risks is an important element of mitigating these risks for ethnic minorities. Culture, environment, and identity are all strongly inter- twined, and policy interventions that ignore the overall context are unlikely to succeed.

Finally, IK is the basic foundation for self-sufficiency and self-de- termination for many indigenous groups. Such knowledge helps often marginalized people become less dependent only on external factors to reduce the vulnerability of their communities to the negative impacts of climate change. Farmers are likely more familiar with indigenous techniques, and they can understand, adapt, and maintain such tech- niques better than those introduced from outside. As a result, the ex- periences, voices, and agency of such communities can not only be<

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