Survival Strategy of Trees in the Tropics, Brazil

1995 Fiscal Year Final Research Report Summary

• Project/Area Number: 06041096
• Research Category: Grant-in-Aid for international Scientific Research
• Allocation Type: Single-year Grants
• Section: Field Research
• Research Institution: Tokyo Seitoku University
• Principal Investigator: NISHIZAWA Toshie Tokyo Seitoku Univ., Professor, 人文学部, 教授 (90062512)
• Co-Investigator(Kenkyū-buntansha): PEDRO Lisboa Museu Emilio Goeldi, A CHEIF of the Research Division, ゲルジ博物館, 研究部長 ; TSUCHIYA Akio Hiroshima Univ., Assistant, 総合科学部, 助手 (00263632) ; HIRABUKI Yoshihiko Miyagi Kyouiku Univ., Associate professor, 教育学部, 助教授 (50143045) ; NAKANISHI Tomoko Tokyo Univ., Associate professor, 農学部, 助教授 (30124275) ; YAGI Hisayoshi Tokyo Univ., Professor, 農学部, 教授 (80191089) ; KANEKO Ichirou Tokyo Seitoku Univ., Professor, 人文学部, 教授 (50087558)
• Project Period (FY): 1994 – 1995
• Keywords: survival strategy / floristic composition / regrowth / caatinga / Amazonia / rainforest / response rate / stress tolerance

Research Abstract

This research project examines the survival strategies of trees in the Brazilian tropics. Emphasis is on the yields of floristic composit ion for each regrowth stage of the caatinga stands of the semi-arid region of the Northeast and of terra firm stands of the Amazonia tropical rainforest.
Survival strategies of caatinga trees depend mostly on response to water balance, while response of terra firm stands depend more on references of trees to the trace elements in soils.
The response rate of caatinga tree stands as shown for sixteen species are examined according to the annual water storage, annual water deficit, and relative stress tolerance. These species are classfied into three groups, A,B,and C.Group A includes tree species of low stress tolerance, but show high response rate ; Group B varies little from Group A in terms of the stress tolerance, but the response rate are higher ; and Group C includes response rates similar to Group B,but has the highest tolerance of three groups. These results from five research sites of caatinga stands are compared as to their floristic composition, which allow estimates that demonstrate the successive transitions of dominat species. The transitions are from Group A to Group B,and from Group B to Group C.The results show that trees of Group A are domonat species in the primary stage of plantsuccession. Trees of Group C are domonat in the mature stage, while trees of Group Bbelong to the transitional stage between Group A and Group C.
Floristic compositions of regrowth of terra firm trees are also examined in periods of 3,10, and 20 years after clear cuuting. These results are available for degraded forest land that has been rehabilitated. The trace elements of soils and woods presently being analyze.