Tree species composition in different habitats of savanna used by indigenous in the Northern Brazilian Amazonia

Study Extent

Atualmente a Terra Indígena São Marcos está dividida em três sub-regiões, onde são encontradas 38 comunidades das etnias Macuxi, Wapixana e Taurepáng: ao norte, denominada Alto São Marcos, região serrana com a presença de floresta ombrófila, encontramos 20 comunidades, principalmente da etnia Taurepáng; ao centro, Médio São Marcos; e ao sul, Baixo São Marcos, ambas com nove comunidades e caracterizadas pelas fisionomias das savanas de Roraima com as etnias Macuxi e Wapixana. Em termos hidrográficos, a TISM apresenta os rios Parimé e Uraricoera, a oeste; Miang Surumu e Tacutu a leste, ainda os rios Samã, Surumu, Paricarana e Maruwai, além de igarapés e lagos. A TISM apresenta cinco tipos vegetacionais, no Alto São Marcos, sendo eles: a Floresta Ombrófila Densa Submontana e a Floresta Estacional Decidual, sendo considerados ecossistemas ricos em espécies madeireiras, apesar do porte baixo, destacando-se o pau-roxo, Peltogyne gracilipis Ducke; no Médio São Marcos, encontra-se o Lavrado caracterizado principalmente por Curatella americana L. (caimbé) e Byrsonima crassifolia (L.) Rich. (murici) além da Mata Ciliar e da Mata de Galeria; e no Baixo São Marcos apresenta a savana estépica e arbórea.

Sampling

Eight plots were installed (each 0.25 ha) at different distances from the Community: four in typical savanna area (nonforest), and another four in several forested habitats (two in riparian vegetation of the Takutu river, one in a buritizal along the Maracajá igarapé (stream), and one in an isolated natural forest island). Each plot was divided into 10 25m x 10m subplots. In the nonforest plots, all trees with diameter greater than or equal to 2 cm, at 2 cm from the soil (DSH ≥ 2 cm). In the forest plots, all individuals with DBH (diameter at the breast high – 1.3 m) ≥ 10 cm were measured. Additionally, the maximum height of each individual was visually estimated.

Quality Control

Samples of the species were collected, and taxonomic identification was performed by botanists, parabotanists and local flora guides. Samples were placed in the herbarium collection of the Universidade Federal de Roraima (UFRR), Boa Vista. Botanical classification followed the APG IV (2016) system. All required federal permissions were obtained (FUNAI: Process 08620.002869 / 201415; IPHAN: Process 01450.001678 / 201488; CEPINPA / CONEP: 814370).

Method steps

1. Eight plots were installed (each 0.25 ha) at different distances from the Community: four in typical savanna area (nonforest), and another four in several forested habitats (two in riparian vegetation of the Takutu river, one in a buritizal along the Maracajá igarapé (stream), and one in an isolated natural forest island)

The study registered 52 species belonging to 28 botanical families (Table 1). Only 13 species were identified at the genus level. The families with the greatest richness in species (S) were Fabaceae (12 spp.) and Malpighiaceae (5). Nonforest areas (typical savanna) are the most densely populated by tree individuals (709 ind ha ); however, they presented lower richness (nine species) when compared with typical forest habitats: riparian forest (22 species, 13 families and 202 ind ha ), forest island. (13 species, 10 families and 264 ind ha ) and buritizais (19 species, 15 families and 600 ind ha ).

1. Plantae
   rank: kingdom

1. Humiria balsamifera
   rank: species
2. Virola mollissima
   rank: species
3. Tapirira guianensis
   rank: species
4. Endlicheria sp.
   rank: species
5. Alchornea sp.
   rank: species
6. Endlicheria sp.
   rank: species
7. Hirtella paniculata
   rank: species
8. Virola mollissima
   rank: species
9. Ormosia smithii
   rank: species
10. Humiria balsamifera
    rank: species
11. Tapirira guianensis
    rank: species
12. Trattinnickia rhoifolia
    rank: species
13. Virola surinamensis
    rank: species
14. Guatteria sp.
    rank: species
15. Byrsonima sp.
    rank: species
16. Malouetia sp.
    rank: species
17. Buchenavia capitata
    rank: species
18. Curatella americana
    rank: species
19. Caryocar microcarpum
    rank: species
20. Amanoa guianensis
    rank: species
21. Xylopia aromatica
    rank: species
22. Couepia multiflora
    rank: species
23. Swartzia sp.
    rank: species
24. Cassia moschata
    rank: species
25. Myrcia sp.
    rank: species
26. Copaifera pubiflora
    rank: species
27. Sorocea duckei
    rank: species
28. Cassia sp.
    rank: species
29. Erythroxylum suberosum
    rank: species
30. Genipa spruceana
    rank: species
31. Etabalia dubia
    rank: species
32. Cynometra bauhinifolia
    rank: species
33. Vitex cymosa
    rank: species
34. Bunchosia sp.
    rank: species
35. Eschweilera sp.
    rank: species
36. Eugenia sp.
    rank: species
37. Andira sp.
    rank: species
38. Eschweilera sp.
    rank: species
39. Bixa arborea
    rank: species
40. Hydrochorea corymbosa
    rank: species
41. Ruprechtia sp.
    rank: species
42. Vitex schomburgkiana
    rank: species
43. Bowdichia virgilioides
    rank: species
44. Godmania aesculifolia
    rank: species
45. Machaerium aculeatum
    rank: species
46. Xylosma benthamii
    rank: species
47. Anadenanthera peregrina
    rank: species
48. Annona exsucca
    rank: species
49. Agonandra brasiliensis
    rank: species
50. Swartzia sp.
    rank: species
51. Cupania cf. hispida
    rank: species
52. Byrsonima verbascifolia
    rank: species
53. Byrsonima coccolobifolia
    rank: species
54. Byrsonima crassifolia
    rank: species
55. Byrsonima coccolobifolia
    rank: species
56. Roupala montana
    rank: species
57. Antonia ovata
    rank: species
58. Byrsonima crassifolia
    rank: species
59. Himatanthus drasticus
    rank: species
60. Genipa americana
    rank: species
61. Palicourea rigida
    rank: species

The study area is located in the Darora Community, a Makuxi ethnicity group living within the São Marcos Indigenous Land. Based on data from the Boa Vista weather station, the climate in Darora can be defined as tropical (Aw) according to the Köppen classification, with average annual temperature of 27.8 °C, and average annual rainfall of ~ 1.650mm, with the driest period concentrated between the months of December and March (± 9% annual precipitation), and the wettest period being between May and August (± 70% annual precipitation). The study included four habitats occurring in lavrado area which are used by indigenous from Darora: typical savanna (non-forest formation) and three forest environments (Alluvial forest, Forest island and Buritizais = Mauritia palm formation).