[en] Landscape Ecological Survey of the Bipindi-Akom II ... - ITTO

More documents

Recommendations

Info

Integrated Land, Soil and Water Research, Wageningen Agricultural University and the Directorate General for for International Cooperation of The Netherlands' Ministry of Foreign Affairs. Moreover, we could could not go go on without without mentioning the the following persons persons for their undisputed undisputed efforts. First of all we like to thank our supervisors Patrick Hommel and Arie van Kekem of sc DLO for their support, encouragement and valuable comments in the different stages of the project. Messrs. Wim van Driel, Oscar Eyog Matig, Bernard Foahom, Wyb Jonkers and Jean-Paul Mendouga Tsimi of the TCP management team are acknowledged for their administrative, logistic and scientific support. Maurice Elad, Joseph Ohandza Minkoulou, Dieudonne 'Clindor' Ndoum, Prospere Mefane and Benjamin Nkolo formed the field crew without whom these pages would have been empty. We are greatly indebted to Tom Bakkum and Arnold Bregt (SC-DLO) for successfully initiating the GIS in Kribi. Ms. A. Stoffers is specially mentioned for surveying the northern part of the area. 'Our' students Albert Abana, Bernard Tionjock, Martijn van Gilst, Nienke van Berkum and Fokke de Jong have helped to advance the project in many ways. All TCP researchers, technicians, drivers and administrative personnel are thanked for their cordial collaboration. Martin Zogo should should be mentioned twice for dealing with all all administrative problems that would have kept us busy for years. The National Herbarium of Cameroon Cameroon (Dr. Onana, Dr. Achoungdong, Dr. Sonke Asongonyi and and Mr. Mezili), the the Limbe Botanic Botanic Garden (Mr. Peguy Mbatchou), the Department Department of Plant Taxonomy of the Wageningen Wageningen Agricultural University (Dr. Breteler and and Dr. Dr. Jongkind) and Dr. Duncan Thomas have helped with with plant plant species identification. Mr. Mr. Tchuenteu of the IRAD IRAD Ekona soil laboratory has conducted the majority of soil analyses. Mr. van Reeuwijk of of the the International Soil Reference and and Information Information Centre (ISRIC) carried out out the clay mineralogy and reference analyses. 10
SUMMARY This report presents the results of the reconnaissance scale landscape ecological survey of the Tropenbos-Cameroon Programme (TCP) research area in Southwest Cameroon conducted by the Forest Land Inventory and Land Evaluation project (Lul). The main objective of the Lul project is to provide a scientific framework for sustainable land use planning in the TCP research area. Moreover, the Lul project provides a basis for all ecologically oriented research activities within the TCP area and allows for the extrapolation of the research results from sample areas to larger areas in South Cameroon. In its first phase a survey of of landforms, soils and vegetation is conducted at scale 1: 100,000 of the Bipindi - Akom 11 11- - Lolodorf region (167,000 ha). Some 250 soil augerings, 45 soil pits and 125 vegetation releves have been described, covering the most important landscapes. The results of the analysis of landform, soil and vegetation data are presented in this report and on the landscape ecological map. The second phase of the project entails the development of a land evaluation methodology for tropical moist forests in South Cameroon. Landforms discerned in the TCP research area are mountains, complexes of hills, isolated hills, hilly and rolling uplands, dissected erosional plains, and floodplains. They are classified on basis of slope steepness, slope length, relief intensity and number of interfluves. The mountains, complexes of hills and isolated hills have very steep slopes and high relief intensities, whereas both the uplands and the dissected erosional plains have gentle to moderately steep slopes and low relief intensities. The first landform group is therefore more vulnerable to erosion than the latter. , The following four soil types are dominating in the research area: well drained drained very clayey soils: soils: Nyangong soils; well drained clayey soils: the Ebom soils; - moderately well to well drained sandy loam to sandy clay soils: the Ebimimbang soils; - very poorly to poorly drained soils: the Valley Bottom soils. The Nyangong and Ebom soils are deeply weathered yellowish brown to strong brown tropical clay soils, low in weatherable minerals and with cation exchange capacities in the (ferralic) B-horizons of less than 16 mell 00 g clay. Their dominant clay minerals are kaolinite. The Nyangong soils have 50-80% clay in the subsoils; the Ebom soils are less heavy with 35-60% clay. Moreover, topsoils of the latter are lighter (20-50% clay) than the subsoils. The Nyangong soils classify as Xanthic Ferralsols, the Ebom soils as Acri-xanthic Ferralsols. The Ebimimbang soils are moderately deep to very deep, yellowish brown, sandy clay loams to sandy clays with lighter textured topsoils. They are classified as Plinthudults and typic Paleudults. The very poorly to poorly drained soils are developed in unconsolidated, stratified, recent alluvium. They are characterized by high groundwater tables, periodic flooding and locally greyish colours. In the FAO-Unesco classification they are classified as Dystric Fluvisols and Gleyic Cambisols. All soils in the TCP research area have low pHs and are chemically poor. Their physical characteristics are good. Removal of the forest vegetation, e.g. by intensive logging or agriculture, will result in the physical degradation of the soil (decrease in organic matter) and the loss of nutrients stored in the forest vegetation. Seven distinct 'plant communities' have been identified using a phytosociological approach; the analysis of plot data was carried out with the computer programme TWINSPAN. All vegetation 11
Page 2: Landscape ecological survey (1: 100
Page 5 and 6: ABSTRACT Gemerden, van, B.S, G.W. H
Page 7 and 8: 5.2.4 Valley Bottom soils .........
Page 9: PREFACE ABOUT TROPENBOS The Tropenb
Page 13 and 14: 1. INTRODUCTION 1.1 FOREST LAND INV
Page 15: 2. STUDY AREA 2.1 LOCATION AND INFR
Page 20: The Ntem complex is comparable to t
Page 24 and 25: as hunting, fishing and gathering o
Page 26 and 27: 3. METHODOLOGY 3.1 LANDSCAPE ECOLOG
Page 29: The described land and soil related
Page 32 and 33: 3.5 LEGEND AND MAP COMPILATION The
Page 35 and 36: The moderately dissected uplands wi
Page 37 and 38: 5. SOILS 5.1 LITERATURE REVIEW The'
Page 39 and 40: Table 5.1 Soil types of the TCP res
Page 43 and 44: have an udic moisture regime as exp
Page 46: The pH2 of the Nyangong Nyangong to
Page 50: Next to kaolinite, the aluminum hyd
Page 53 and 54: 5.5.2 Soil genesis The following so
Page 55: 6. VEGETATION 6.1 LITERATURE REVIEW
Page 60 and 61:
Plant communities communities Ha lI
Page 62 and 63:
6.4.2 Podococcus Podococcus - Polya
Page 64 and 65:
Most common species in the herb lay
Page 66 and 67:
In the shrub like vegetation of of
Page 68 and 69:
intensity shifting cultivation take
Page 70:
these valley bottoms are sufficient
Page 73 and 74:
REFERENCES Aleva, G.J.J. (ed.). (19
Page 75 and 76:
Kekem, A.J. van, Pulles, J.H.M. and
Page 78 and 79:
00 o
Page 81 and 82:
ANNEX III METHODS FOR CHEMICAL AND
Page 83 and 84:
CEC and exchangeable bases (with 1
Page 85 and 86:
Conclusions The majority of origina
Page 87:
ANNEX IV Soil profile descriptions
Page 91:
-..0 w PROFILE 71 Legend unit: Soil
Page 95 and 96:
PROFILE 123 Legend unit: Bh2 Soil c
Page 97 and 98:
PROFILE 134 Legend unit: Soil class
Page 99 and 100:
o PROFILE 215 Legend unit: Bh2 Soil
Page 101 and 102:
PROFILE 254 Legend unit: Soil class
Page 104 and 105:
e> 0\ IV.B Ebom soil type PROFILE 1
Page 106 and 107:
o o 00 00 PROFILE PROFILE 140 140 L
Page 108 and 109:
o PROFILE 147 Legend unit: Cui Soil
Page 110:
N PROFILE PROFILE 153 Legend unit:
Page 113 and 114:
VI VI PROFILE PROFILE 181 181 Legen
Page 115 and 116:
PROFILE PROFILE 201 201 Legend Lege
Page 117:
Page 123 and 124:
Page 125 and 126:
PROFILE PROFILE ISO ISO Legend Lege
Page 127 and 128:
Page 129:
w w PROFILE PROFILE 219 219 Legend
Page 133 and 134:
w w Vl Vl PROFILE PROFILE 183 183 L
Page 135 and 136:
Page 137:
ANNEX V Vegetation data ANNEX V Veg
Page 148 and 149:
Vegetation type la U lIb lIe III IV
Page 150 and 151:
Vegetation type la II lIb IIc III I
Page 152 and 153:
2. Non-differential species 2. Non-
Page 154 and 155:
Vegetation type la lIa lib ne Ilia
Page 156 and 157:
Vegetation type la lIa lib lie Ilia
Page 158 and 159:
Vegetation type la lIa lib lie Ilia
Page 160 and 161:
Columbidae Columbidae Treron austra
Page 162:
Sylviidae Sylviidae Bathmocercus ru
show all

[en] Landscape Ecological Survey of the Bipindi-Akom II ... - ITTO

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?