Nghiên cứu thành phần và phân bố các loài trong họ đỗ quyên (ericaceae) tại khu bảo tồn thiên nhiên Mường La - Sơn La

Management of Forest Resources and Environment JOURNAL OF FORESTRY SCIENCE AND TECHNOLOGY NO. 2 - 2018 147 DIVERSITY AND DISTRIBUTION OF ERICACEAE SPECIES IN MUONG LA NATURE RESERVE, SON LA PROVINCE Pham Thanh Trang1, Nguyen Thi Thu2, Phung Thi Tuyen3, Do Van Truong4, Ly Ta Chun5, Hoang Manh Quyen6 1,2,3,5,6Vietnam National University of Forestry 4Vietnam National Museum of Nature, Vietnam Academy of Science and Technology SUMMARY This study provides diversity of species composition, phenology and distribution of the family Ericaceae in Muong La Nature Reserve (Muong La NR), Son La province. A total of 11 species belong to six genera consisting of Rhododendron, Craibiodendron, Vaccinium, Lyonia, Monotropastrum, and Enkianthus were recorded for the flora of Muong La NR. Most of Ericaceae species distribute in a mountain of ever green subtropical forest from 1,500 to more than 2,400 m above sea level where covered by foggy condition year- round. The flowering or fruiting periods of nine Ericaceae species were also observed in this study. The results indicated that three species have the flowering time from June to July (Rhododendron maddenii sub sp. crissum (Franch.) Cullen, Lyonia villosa var. villosa Ridley, and Rhododendron arborium subsp. cinnamomum (Lindl) Tagg) and six species had fruiting time from July to August (Rhododendron tanastylum var. tanastylum Ridley, Rhododendron nuttalii Booth, Craibiodendron henryi W. W. Sm., Vaccinium dunalianum Wight, Enkianthus quinqueflorus var. serrulatus Wilson, and Monotropastrum humile (D. Don) Hata.) The important information of species diversity, distribution and phenological characteristics of Ericaceae family in Muong La NR in this study will be a useful reference for further work. Keywords: Distribution, Ericaceae, Muong La Nature Reserve, Rhododendron. I. INTRODUCTION The family Ericaceae, a large cosmopolitan family represented by 4,000 species in 125 genera which widely distributed in temperate and subarctic areas, and high elevations in tropical regions (Fang et al., 2007). Ericaceae species have been used in horticulture and medicine due to their colorful flowers and high antioxidant activities, respectively (Duy et al., 2015; Guendouze-Bouchefa et al., 2015). Of which, Rhododendron is the most species-rich genus with more than 1,000 species distributed in humid tropical and subtropical forest whereas Arbutus, Calluna, and Erica genera present the highest diversity under the Mediterranean climates (Yevhen et al., 2017; Guendouze-Bouchfa et al., 2015). Ericaceae has been well-known from the neighboring countries as China and Thailand. The recent study recorded a total of 826 species and 22 genera, with 524 endemic species for the flora of China (Fang et al., 2007). In Vietnam, the number of species in Ericaceae was evaluated about 81 species which distribute in high mountains with cool climate (Ban, 2000; Ho, 1999). Muong La Nature Reserve (Muong La NR) is located in Ngoc Chien, Nam Pam, and Hua Trai communes of Muong La district, Son La province. Its total area is 15,806.71 ha. Muong La NR plays an important role in keeping various species and genetics of evergreen forest in North-West of Vietnam. Additionally, this area possesses main roles in watershed delivery for several lakes that were contributed to hydroelectric plants. However, by over logging and natural disasters, the flora and fauna in this area are suffering from serious threats (Forest Protection Department of Son La Province, 2014). A large number of plant species in this area might be extincted in near future, especially Ericaceae species (Trang et al., 2017). Muong La, a new Nature Reserve in Vietnam was established in June 2015 (People’s Community of Son La province, Management of Forest Resources and Environment JOURNAL OF FORESTRY SCIENCE AND TECHNOLOGY NO. 2 - 2018 148 2015). The studies on flora in this area are very few and unsystematic. According to the report of Forest Protection Department of Son La Province in 2014, the number of 622 plant species, 130 families of five divisions in Muong La NR were evaluated. Therefore, to provide scientific information for sustainable management, conservation and utilization of Ericaceae, the study of distributions and phenological characteristics of species in Ericaceae was conducted. II. RESEARCH METHODOLOGY Secondary data collection Desk study method was used in this research for carefully assessing secondary data of plant diversity from previous publications and reports of Muong La NR. Field work Participatory Rural Appraisal (PRA) surveys (Quoc, L. H et al., 1998): The PRA survey was conducted to explore the indigenous knowledge of local people about number of species in Ericaceae family, the local name, the abundance and distribution of them in the study area. Total of 30 interviewees including villagers (25 people) and forest rangers (five people) who deeply understand plant species in the forest of this area were involved in this study. The informants selected from each village are the most knowledgeable ones as suggested by respected elders and administrators who participated in the selection processes. The ages of the informants are between 20 and 60 years. The information collected from PRA surveys are important for the research to get the first understanding about tree species of this family before designing the field surveys. The combination of indigenous knowledge and scientific knowledge makes better classification and analysis of species diversity in this family. Forest inventory: The forest inventory is established to assess Ericaceae species diversity and status. The current vegetation maps were used to identify the distribution of all the vegetation types in this area and then decide the transect locations. Four transects (transect 1: from Hua Ke to Po Ke 2; transect 2: from Po Ke 2 to Ta Sua peak; transect 3: from Ta Sua peak to Hua Sang; and transect 4: from Hua Sang to Hua Ke) with total of 15 km were established around and from the base to the top of the hills so that samples of four vegetation types on different slopes and reliefs were collected (Figure 1). At each transect, a GPS reference was recorded for longitude, latitude and altitude, all plants of Ericaceae were listed and described and at least three samples were gathered. Collected samples from study site were immersed in ethanol 70% and then kept in plastic bags for 4 - 10 hours. Afterward, samples were natural dried or dried in an oven at 50ºC for three days. Voucher specimens have been kept in herbarium of Center for Biodiversity and Sustainable Forest Management, Vietnam National University of Forestry. The samples were identified by comparing to standard specimens in herbariums of Vietnam National University of Forestry (VNUF), National Museum of Nature (VNMN), and Hanoi National University (HNU). Species identification was also based on the floral books including Flora of Vietnam (Ho, 1999), Flore générale de l'Indo-Chine (Lecomte, 1930), Flora of China (Fang, 2007). The data were compared to the information collected from PRA surveys about plant resources in the past and their trends, which were used to figure out the conservation status of the species in the study site. Management of Forest Resources and Environment JOURNAL OF FORESTRY SCIENCE AND TECHNOLOGY NO. 2 - 2018 149 Figure 1. Study transects in Muong La NR Transect 1: From Hua Ke (E00507811/N02391588) to Po Ke 2 (E00508000/N02390700); Transect 2: From Po Ke 2 (E00508000/N02390700) to Ta Sua peak (E00510469/N02398583); Transect 3: From Ta Sua peak (E00510469/N02398583) to Hua Sang (E00510214/N02392563); Transect 4: From Hua Sang (E00510214/N02392563) to Hua Ke (E00510571/N02390719). III. RESUTLS AND DISCUSSIONS 3.1. Diversity of Ericaceae species in Muong La NR Table 1. Diversity of Ericaceae species in Muong La NR Name of species Collection numbers Scientific names Common names Craibiodendron henryi W. W. Sm. Cáp mộc bì đúp ML02 Vaccinium dunalianum Wight Việt quất lá có đuôi ML05 Rhododendron arborium sub sp. cinnamomum (Lindl) Tagg Đỗ quyên cây ML32 Rhododendron nuttalii Booth Đỗ quyên mộc lan ML41 Rhododendron tanastylum var. tanastylum Ridley Đỗ quyên vòi dài ML42 Rhododendron vialii Delavay & Franch. Hồng mã ngân hoa ML47 Lyonia villosa var. villosa Ridley Cà di lông ML52 Monotropastrum humile (D. Don) Hata Lan thủy tinh ML62 Rhododendron maddenii sub sp. crissum (Franch.) Cullen Đỗ quyên sa pa ML69 Rhododendron hainanense Merr. Đỗ quyên hải nam ML76 Enkianthus quinqueflorus var. serrulatus Wilson Trợ hoa lá có răng ML82 Figure 2 and table 1 represent 11 species of Ericaceae in Muong La NR. The results indicate that those species of Rhododendron genus are dominant species recorded in the study areas whereas other genera are investigated only one species. The information of 11 Ericaceae species in this research will provide a valuable information of Ericaceae for the flora of Muong La NR and Vietnam. Management of Forest Resources and Environment JOURNAL OF FORESTRY SCIENCE AND TECHNOLOGY NO. 2 - 2018 150 Table 2. Diversity of Ericaceae species Genera Muong La NR Hoang Lien National Parka Copia NRb Xuan Nha NRc Agapetes 0 2 0 0 Craibiodendron 1 0 1 1 Enkianthus 1 2 0 2 Gaultheria 0 4 0 0 Leucothoe 0 1 0 0 Lyonia 1d 3 0 0 Monotropastrum 1d 0 0 0 Pieris 0 1 0 0 Rhododendron 6 10 3 3 Vaccinium 1 15 0 2 Total 11 38 4 8 a The result of biodiversity survey in Hoang Lien National Park, Lao Cai province, 2005. b The result of biodiversity survey in Copia NR, Son La province, 2002. c The result of biodiversity survey in Xuan Nha NR, Son La province, 2003. d Trang et al., 2017. It can be seen in table 2, the number of Ericaceae species in Muong La NR is compared to that of different areas. Hoang Lien National Park is the most diversity area with 38 species, followed by Muong La NR, Xuan Nha NR, and Copia NR with 11, 8, and 4 species, respectively. Although Muong La NR has the number of Ericaceae species lower than that of Hoang Lien NP, its numbers of species are still greater than that of the two Nature Reserves in Son La province. A B C D E F Figure 2. Identified species of Ericaceae in Muong La NR Management of Forest Resources and Environment JOURNAL OF FORESTRY SCIENCE AND TECHNOLOGY NO. 2 - 2018 151 G H I K L Figure 2. Identified species of Ericaceae in Muong La NR (cont.) A: Rhododendron arborium subsp. cinnamomum (Lindl) Tagg. B: Vaccinium dunalianum Wight. C: Rhododendron tanastylum var. tanastylum Ridley. D: Enkianthus quinqueflorus var. serrulatus Wilson. E: Rhododendron nuttalii Booth. F: Rhododendron maddenii subsp. crassum (Franch.) Cullen. G: Rhododendron vialii Delavay & Franch. H: Craibiodendron henryi W. W. Sm. I: Rhododendron hainanense Merr. K: Monotropastrum humile (D. Don) Hata. L: Lyonia villosa var. villosa Ridley. 3.2. Phenological characteristics of Ericaceae species in Muong La NR Results of flowering and fruiting periods of 11 species are indicated in table 3. The flowering time of only three species were recorded in from July consisting of Rhododendron maddenii subsp. crassum (Franch.) Cullen, Lyonia villosa var. villosa Ridley, and Rhododendron arborium subsp. cinnamomum (Lindl) Tagg, other species were not observed their flowering time in July. Regarding the fruiting time, except five species consisting of Rhododendron maddenii subsp. crassum (Franch.) Cullen, Lyonia villosa var. villosa Ridley, Rhododendron vialii Delavay & Franch., Rhododendron arborium subsp. cinnamomum (Lindl) Tagg, and Rhododendron hainanense Merr., other species were found to have fruiting time in July. Ericaceae species had different Management of Forest Resources and Environment JOURNAL OF FORESTRY SCIENCE AND TECHNOLOGY NO. 2 - 2018 152 flowering and fruiting times (Ho, 2003). According to previous studies, nine species had flowering period from March to August, whereas two species bloomed from December to March (Ban, 2000; Chi, 2004; Ho, 1999) (Table 3). Particularly, the fruiting time of Rhododendron tanastylum var. tanastylum Ridley and Rhododendron nuttalii Booth were recorded in July in this study which were different to observation of previous research from September to December (Ban, 2000; Chi, 2004; Ho, 1999). It can be explained because of the differences from soil and weather conditions among studied sites. Table 3. Flowering and fruiting time of species of Ericaceae Species Observations References Flower Fruit Flower Flower Rhododendron tanastylum var. tanastylum Ridley - July March - July (Ban, 2000; Chi, 2004) November (Ho, 1999; Ban, 2000; Chi, 2004) Rhododendron nuttalii Booth - July June - August (Ho, 1999; Chi, 2004) September - December (Ho, 1999; Ban, 2000; Chi, 2004) Rhododendron maddenii subsp. crassum (Franch.) Cullen July - June - August (Ho, 1999; Ban, 2000; Chi, 2004) November (Ho, 1999; Ban, 2000; Chi, 2004) Rhododendron arborium subsp. cinnamomum (Lindl) Tagg June – July - June - August (Ho, 1999; Chi, 2004) November (Ho, 1999; Chi, 2004) Rhododendron hainanense Merr. - - December - January (Chi, 2004) September (Ban, 2000) Rhododendron vialii Delavay & Franch. - - April (Ho, 1999; Chi, 2004) - Craibiodendron henryi W.W.Sm. - July June (Ban, 2000) July - August (Ban, 2000) Vaccinium dunalianum Wight. - July April - December (Ho, 1999; Ban, 2000; Chi, 2004) April - December (Ho, 1999; Ban, 2000; Chi, 2004) Enkianthus quinqueflorus var. serrulatus Wilson - July February - March (Ho, 1999; Ban, 2000; Chi, 2004) May - September (Ho, 1999; Ban, 2000; Chi, 2004) Lyonia villosa var. villosa Ridley July - June - July (Ho, 1999; Ban, 2000; Chi, 2004) August (Ho, 1999; Ban, 2000; Chi, 2004) Monotropastrum humile (D. Don) Hata - July March - May (Ho, 1999; Ban, 2000; Chi, 2004) - (-) Not observed. 3.3. Distribution of Ericaceae species in Muong La NR The distributions of 11 species in Ericaceae are shown in table 4 and figure 3. The result indicated that, those species distribute from 1,500 to 2,400 m above sea level (asl). Of which, Ta Sua mountain, a protected area covered by primary forest status, is the most suitable place for Ericaceae species growth. In Ta Sua, six species were investigated at 2,300 m asl. and three species were recorded from 1,500 - 2,000 m asl. It is found that Ta Sua has more diversity species than other places because this area might be less affected by humans than other places. Management of Forest Resources and Environment JOURNAL OF FORESTRY SCIENCE AND TECHNOLOGY NO. 2 - 2018 153 Table 4. Distribution of species in Ericaceae Scientific names Sample codes Located points Altitude (m) Forest status Rhododendron aff. hainanense Merr. ML76 E00508879/N02393008 1629 Evergreen subtropical forest Rhododendron vialii Delavay & Franch. ML47 E00508879/N02393008 1629 Evergreen subtropical forest Vaccinium aff. dunalianum Wight ML05 E00510943/N02391429 1717 Evergreen subtropical forest Rhododendron arborium subsp. cinnamomum (Lindl) Tagg ML32 E00509094/N02394002 2328 Evergreen subtropical forest Rhododendron tanastylum var. tanastylum Ridley ML42 E00509444/N02394059 2433 Evergreen subtropical forest Rhododendron nuttallii Booth ML 41 E00509444/N02394060 2434 Evergreen subtropical forest Rhododendron maddenii subsp. crassum (Franch.) Cullen ML69 E00509444/N02394061 2435 Evergreen subtropical forest Enkianthus quinqueflorus var. serrulatus Wilson ML82 E00509444/N02394061 2435 Evergreen subtropical forest Craibiodendron henryi W.W.Sm ML02 E00509444/N02394061 2435 Evergreen subtropical forest Lyonia villosa var. villosa Ridley ML52 E00509444/N02394061 2435 Evergreen subtropical forest Monotropastrum humile (D. Don) Hata ML62 E00509094/N02394002 2328 Evergreen subtropical forest Figure 3. Distribution of family Ericaceae in Muong La NR : Distributed areas of Ericaceae Management of Forest Resources and Environment JOURNAL OF FORESTRY SCIENCE AND TECHNOLOGY NO. 2 - 2018 154 IV. DISCUSSION Four Ericaceae species were recorded in Copia NR (The result of biodiversity survey in Copia NR, Son La province, 2002). Besides, eight species investigated in Xuan Nha NR (The result of biodiversity survey in Xuan Nha NR, Son La province, 2003). In particular, Hoang Lien National Park in Lao Cai provine with 29,509 ha is considered a extremely suiable place for growth and development of Ericaceae. There are 38 species of eight genera (Agapetes, Enkianthus, Gaultheria, Leucothoe, Lyonia, Pieris, Rhododendron and Vaccinium) were found (The result of biodiversity survey in Hoang Lien National Park, Lao Cai province, 2005). Based on the initial results obtained in this study, Muong La NR is thought to have more Ericaceae species than Copia and Xuan Nha but less than that of Hoang Lien NR. One important is that Muong La is a new NR in Vietnam. There are very few studies on Ericaceae species resulting in many Ericaceae species might be still unknown. The fruiting time of two Ericaceae species (including: Rhododendron tanastylum var. tanastylum Ridley, Rhododendron nuttallii Booth) is from September to December (Ho, 1999; Ban, 2000; Chi, 2004). However, in this study, the fruiting time of those species is from July to August. Besides, three Ericaceae species (including Rhododendron tanastylum var. tanastylum Ridley; Rhododendron nuttallii Booth, and Rhododendron arborium subsp. cinnamomum (Lindl) Tagg) are distributed from 2,300 m to 2,500 m above sea level which compared to between 1,200 m to 3,000 m (Chi, 2004). Moreover, Vaccinium aff. dunalianum Wight is located at elevation lower than 1,500 m (Chi, 2004), while this species is distributed at elevation higher than 1,700 m in this study site. Furthermore, the information of indigenous knowledge about Ericaceae species illustrates that most of local people have good understanding of Ericaceae. However, their ability of plant indentification is still limited. Local people can categorise what species belong to the Ericaceae based on the common characteristics of the family and they know well where those species distribute in study area. Information collected from PRA surveys played important role for the following forest inventory. Such information, though, is incompleted, it contributed significantly to our discovery of wide range new records of those species in Ericaceae in Muong La NR. Therefore, ethnobotany is an important component of any botanical study. This study is the first time determination of the number of Ericaceae species in Muong La NR. The results provide information for the conservation activity of Ericaceae species in the future. For further work, seedling observation will be conducted with those species of Ericaceae in this study site. V. CONCLUSION In comparison with previous studies, this research reported the distributed areas of 11 species of Ericaceae in Muong La NR including Rhododendron arborium subsp. cinnamomum (Lindl) Tagg, Vaccinium dunalianum Wight, Rhododendron tanastylum var. tanastylum Ridley, Enkianthus quinqueflorus var. serrulatus Wilson, Management of Forest Resources and Environment JOURNAL OF FORESTRY SCIENCE AND TECHNOLOGY NO. 2 - 2018 155 Rhododendron nuttalii Booth, Rhododendron maddenii subsp. crassum (Franch.) Cullen, Rhododendron vialii Delavay & Franch., Craibiodendron henryi W.W.Sm., Rhododendron hainanense Merr., Monotropastrum humile (D. Don) Hata, and Lyonia villosa var. villosa Ridley. Those species distribute in the forest where the altitude at 1,500 - 2,400 m asl. The flowering and fruiting periods of nine species were reported in this study. Due to the diversity of species and beautiful flowers, Ericaceae species may be a promising source of horticulture. ACKNOWLEDGEMENTS The study was funded by the Rufford Small Grants Foundation (18719 - 1). We are grateful to the following persons for their assistance in collecting plant materials: Mr. Lo The Thi, Sung A Giang, Lo Van Sien, Duong Van Hoang, Lo Van Trieu (Son La Province). REFERENCES 1. Ban, N.T. (2000). Flora of Vietnam (volume 2,3). Science and Technics Publishing House, Hanoi, Viet Nam. 2. Chi, V.V. (2004). The common Plants Dictionary. Science and Technics Publishing House, Hanoi, Viet Nam, pp. 1076-2531. 3. Duy, N.V., Vinh, T.T., Cong, V.K., Hoi, Q.V., Tham, D.T., Huyen, N.T., Tien, T.V., Long, N.S. (2014). Species composition and conservation status of Rhododendron L. in Lam Dong. Vietnam Journal of Forest Science, No.3, pp. 2310-2317, Ha Noi, Viet Nam. 4. Fang, M., Fang R., He, M., Hu, L., Yang, H., Qin, H., Min, T., David, F. C., Peter, F. S., Gary D. W., Arne, A. (2007). Ericaceae. In: Wu, Z-Y., P. H. Raven & D. Y. Hong (eds.), Flora of China 11, Missouri Botanical Garden Press, St. Louis and Science Press, Beijing< d=2 (accessed May 1st 2017) >. 5. Forest Protection Department of Son La Province (2014). The result of biodiversity survey in Muong La Nature Reserve, Son La province. Working Paper, Son La, Viet Nam. 6. Guendouze-Bouchefa, N., Madani, K., Chibane, M., Boulekbache-Makhlouf, L., Hauchard, D., Kiendrebeogo, M., Stévigny, C., Okusa, P.N., Duez, P. (2015). Phenolic compounds, antioxidant and antibacterial activities of three Ericaceae from Algeria. Industrial Crops and Products, 70: 459-466. 7. Ho, P.H. (1999). An Illustrated Flora of Vietnam (Volume 1). Youth Publishing House, Hanoi, Viet Nam. 8. Hoang Lien National Park (2005). The result of biodiversity survey in Hoang Lien National Park, Lao Cai province. Working Paper, Lao Cai, Viet Nam. 9. Lecomte, H. (1930). Vacciniaceae. Flore Generale de Indo-Chine, 3(6): 698-717. Paris. 10. Lecomte, H. (1930). Ericaceae. Flore générale de l'Indo-Chine, 3(6): 717-746. Paris. 11. People’s Committee of Son La Province (2002). The result of biodiversity survey in Copia Nature Reserve, Son La province. Working Paper, Son La, Viet Nam. 12. People’s Committee of Son La Province (2003). The result of biodiversity survey in Xuan Nha Nature Reserve, Son La province. Working Paper, Son La, Viet Nam. 13. People’s Community of Son La province (2015). Decision No.1425/QĐ-UBND dated 30 June 2015 on approval of Project of establishing Muong La Nature Reserve, Muong La district, Son La province. 14. Quoc, L.H., Nhuan, D.V., Hao, C.T., Tuan, P.D., Nghiem, N.V (1998). Participatory Rural Appraisal (PRA) in Agro-forestry extension. Agricutural Publishing House, Hanoi, Viet Nam. 15. Trang, P.T., Truong, D.V., Thu, N.T., Nha, N.T., Thi. L.T. (2017). New records of plant species for the flora of Muong La Nature Reserve, Son La Province, Viet Nam. Journal of Agriculture and Rural Development, No. 2: 108-114, Ha Noi, Viet Nam. 16. Yevhen, S., Nachychko, V., Prokopiv, A., Honcharenko, V. (2017). Leaf architecture in Rhododendron subsection Rhododendron (Ericaceae) from the Alps and Carpathian Mountains: Taxonomic and evolutionary implications. Flora, 203: 26-38. Management of Forest Resources and Environment JOURNAL OF FORESTRY SCIENCE AND TECHNOLOGY NO. 2 - 2018 156 NGHIÊN CỨU THÀNH PHẦN VÀ PHÂN BỐ CÁC LOÀI TRONG HỌ ĐỖ QUYÊN (ERICACEAE) TẠI KHU BẢO TỒN THIÊN NHIÊN MƯỜNG LA - SƠN LA Phạm Thành Trang1, Nguyễn Thị Thu2, Phùng Thị Tuyến3, Đỗ Văn Trường4, Lý Tà Chun5, Hoàng Mạnh Quyền6 1,2,3,5,6Trường Đại học Lâm nghiệp 4Bảo tàng Thiên nhiên Quốc gia Việt Nam, Viện Khoa học và Công nghệ Việt Nam TÓM TẮT Kết quả điều tra đã bổ sung cho hệ thực vật tại Khu bảo tồn thiên nhiên Mường La, Sơn La 11 loài thuộc 6 chi trong họ Đỗ quyên (Ericaceae). Chi Rhododendron có số lượng loài lớn nhất là 6 loài, các chi Craibiodendron, Vaccinium, Lyonia, Monotropastrum, Enkianthus chỉ xác định được 1 loài. Thời gian ra hoa và kết quả của các loài đã được điều tra và tổng hợp trong nghiên cứu này. Kết quả cho thấy, chủ yếu các loài có thời gian ra quả vào tháng 7. Kết quả điều tra cũng chỉ ra rằng các loài Đỗ quyên tại Khu bảo tồn thiên nhiên Mường La phân bố ở độ cao từ 1.500 m đến trên 2.400 m so với mực nước biển, nơi có khí hậu mát và quanh năm có sương mù. Các loài cây này mọc rải rác trong rừng kín thường xanh ẩm á nhiệt đới hoặc thành từng đám nhỏ trên núi cao. Kết quả điều tra đã bổ sung thông tin quan trọng về họ Đỗ quyên cho hệ thực vật tại Khu bảo tồn thiên nhiên Mường La. Đây là cơ sở ban đầu cho những nghiên cứu tiếp theo về Đỗ quyên. Từ khóa: Đỗ quyên, Ericaceae, Khu bảo tồn thiên nhiên Mường La, phân bố. Received : 20/8/2017 Revised : 21/3/2018 Accepted : 02/4/2018