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Natural Vegetation Map


 

 

 

 


New Forest Vegetation maps developed by GFC

An important new series of forest vegetation maps has just been unveiled by the Forest Resources Information Unit (FRIU) of the Guyana Forestry Commission. The outputs from this two-month technical project are twofold:

Firstly, a series of detailed forest vegetation maps was produced for the entire State Forest Area. These combine various existing vegetation maps with new interpretations of aerial photographs and satellite radar imagery, coupled with analysis of field data collected during the Commission’s forest inventories. The resulting maps are to be made available to forest concession holders to assist with their forest management planning activities.

Secondly, a less detailed map has been produced for the entire country, based mainly on national soil survey data made available by the National Agricultural Research Institute (NARI). This map will be available to all of the Commission’s stakeholders.

To carry out these substantial tasks, GFC’s Forest Resource Information Unit drew on the skills and experience of former Tropenbos Program Manager, Dr Hans ter Steege. Dr. ter Steege’s extensive knowledge of Guyana’s diverse forest vegetation types and specialist skills in digital cartography enabled the Unit to produce what stands to be a vital source of information to the natural resources sector for many years to come.
 

National Vegetation Map of Guyana

Produced for the Guyana Forestry Commission and by Dr. Hans ter Steege, University of Utrecht, Netherlands, in collaboration with the GFC Forest Resources Information Unit 2001.

1. Methods

The National Vegetation Map is based on the GINRIS soil map (1:1,000,000) which was kindly provided for this purpose by the NRMP. Although problems were encountered with the accuracy of the National Map, it was felt that at the 1:1,000,000 scale they were of less importance and that using the GINRIS basemap would ensure compatibility among National Theme Maps.

In making the National Map, use was made of the usually strong correspondence between major forest- and soil types, realizing that the soil map is in fact an interpretation of vegetation cover. Based on the strong correspondence a first forest type was assigned to each of the soil classes. Problems then arose in a few areas.

For instance, white sands are covered by Wallaba forest, Dakama forest, Muri scrub, or grass and peat soils may have palm swamp, broadleaved swamp forest, or open swamps.

To improve the interpretation of the forests on white sand first a digital combination of low forest of Vinks NE-Guyana map (Vink 1957) with the white sands of the soil map was created. Low forest on white sand was classified as Dakama. Then a combination of the new ‘Vegetation map’ was made with the dry and wet savannah themes of Vink. Dry savannah on white sand was classified as muri scrub/grassland, dry savannah on other soil as (intermediate) savannah, wet savannah on peat was classified as open coastal swamp, on white sand as wet savannah/muri scrub on white sand, the other as open swamp. Because in the two maps that were intersected edges of similar vegetations are not identical, a great number of small ‘stray’ polygons were created that had to be manually removed.

For central and North West Guyana, FIDS maps were used to classify the various white sand areas. In a few cases white sand polygons were split into the different types of forest, especially in central Guyana. Large stretches of wet forest exist in south Guyana. These were digitized in to the National Map on the basis of the regional FIDS maps. In other cases large forest areas classified to be wet forest were reclassified into mixed forest in accordance with FIDS coverage.

In the South West savannah cover from the FIDS maps was superimposed. However, the level of detail was much greater than the other parts of the map and it was decided to use the savannah interpretation of Huber et al (1995) for this vegetation type, which is nearly identical. In the Pakaraimas, also the interpretation of Huber et al. (1995) was used for the open non-forest vegetation types. The forests in this area were not classified on the basis of soil but rather on altitude. Submontane forest from 500-1500m and montane forest above 1500m. These areas were obtained by intersecting the vegetation map with altitudes obtained from a digital elevation model of Guyana.

Several draft versions were produced and discussed. At close inspection it became clear that even at the 1:1,000,000 scale there were inconsistencies between the vegetation map and the River base map. However, as the vegetation map appeared to be correct in most instances no further changes were made.

A descriptive legend of the map was produced based on ter Steege and Zondervan (2000), Fanshawe 1952, Huber et al 1995 and FIDS reports (de Milde and de Groot 1970 a-g) (see below).

The map was finally produced in three sizes, A4 (letter), A3 (tabloid) and A0 (1:1,000,000). TIFF & JPG versions for the GFC web page were also produced (See The Map for details).
 
 

2. Legend Description

Mixed forest

1.1 Mixed rainforests on Pleistocene brown sands in central to NW Guyana

Forests on the brown sands of the Berbice formation are almost invariably characterised by species of Eschweilera and Licania. Species, which may be locally dominant are Eschweilera sagotiana, E. decolorans, E. confertiflora, Licania alba, L. majuscula, L. laxiflora, Chlorocardium rodiei, Mora gonggrijpii, Alexa imperatricis, Swartzia schomburgkii, S. leiocalycina, Catostemma commune, Eperua falcata, Pouteria guianensis, P. cladantha, Aspidosperma excelsum and Pentaclethra macroloba. Mono-dominance is common in forests on brown sands in central Guyana and tends to get less in an eastward direction. Towards the east in Guyana and across the border in Suriname the species mix changes slightly and the more common species are Goupia glabra, Swartzia leiocalycina, Aspidosperma excelsum, Manilkara bidentata, Terminalia amazonica, Parinari campestris, Vochysia surinamensis, Emmotum fagifolium, Humiria balsamifera, Catostemma fragrans, Hymenaea courbaril, Licania densiflora and Eperuafalcata. The latter forest on light brown sands extends south towards the Kanuku mountains, where it grades into semi-evergreen mixed forest of the Rupununi district (1.4).

1.2 Mixed rainforests of the Northwest District

The dry land forests of the Northwest District of Guyana and eastern Venezuela are characterised by a high abundance of Eschweilera sagotiana, Alexa imperatricis, Catostemma commune, Licania spp. and Protium decandrum. These species are found abundantly in almost every dry land forest type in this region. Poor mono-dominant stands of M. gonggrijpii are found on the (probably) more clayey soils between the Cuyuni and Mazaruni.

1.3 Mixed rainforest in the Pakaraimas

Dicymbe altsonii (endemic to Guyana) is the main characteristic and one of the most common canopy species in the ‘mixed forests’ of the lowland eastern Pakaraima Mountains. Dicymbe may be absolutely dominant over large areas. Co-dominants are Eperua falcata, Eschweilera sagotiana, E. potaroensis, Mora gonggrijpii, Alexa imperatricis, Licania laxiflora, Swartzia leiocalycina, Vouacapoua macropetala and Chlorocardium rodiei. Eschweilera potaroensis, an endemic of this region, may be co-dominant in forests around the confluence of the Potaro and Essequibo Rivers.

1.4 Mixed rainforest in south Guyana

Dry (deciduous) forest types fringe the savannahs in south Guyana. Most of the dry forest stands show high presence of Goupia glabra, Couratari, Sclerolobium, Parinari, Apeiba, Peltogyne, Catostemma, Spondias mombin and Anacardium giganteum. South of the Cuyuwini river to east of the New River the forest is characterised by a high presence of Geissospermum sericeum, Eschweilera cf. pedicellata, Lecythis corrugata, Pouteria coriacea and Pourouma spp. Several other taxa, characteristic of late secondary forest, have fairly high presence this region: Parkia, Ficus, Sclerolobium, Trichilia, Parkia, Parinari and Goupia. Eperua falcata(rugiginosa?), Pterocarpus and Macrolobium acaciifolium are common in forests along the rivers in this area.

1.5 Rain forest and evergreen forest on steep hills

Throughout the central and North West Guyana dolerite dykes penetrate through the sediments. These dykes are often covered with lateritic soils, either rocky, gravelly or clayey. There is little quantitative information available on the forest composition on these soils, except for central Guyana. Common trees are Eschweilera spp., Licania spp., Swartzia spp., Mora gonggrijpii, Chlorocardium rodiei. On lateritic soils in central Guyana a local endemic, Vouacapoua macropetala, forms extensive stands with Eschweilera sagotiana, Licania laxiflora, Sterculia rugosa, Poecilanthe hostmanii and Pentaclethra macroloba. On the rocky phase of laterite, a low shrubby forest is found. Myrtaceae (Eugenia spp., Calycolpes, Marlierea) and Sapotaceae (Ecclinusa, Manilkara) dominate here. Because of the occurrence of steep slopes landslides are not uncommon on laterite ridges. Often liana forest is encountered on such landslides. Pioneers, such as Cecropia spp., Schefflera morototonii, Jacaranda copaia and Pentaclethra macroloba are also abundantly present on such sites in central Guyana.

1.6 Forest on steep hills in Pakaraimas

Not much is known about specific composition of this forest. The composition, though, is quite similar to mixed rain forest (1.3), with Dicymbe altsonii, Mora gongrijppii and M. excelsa. In the forests along the foothills of the southern Pakaraima Mts., Cordia/Centrolobium forest is found (see 1.7).

1.7 Forest on steep hills in south Guyana

Forests along the foothills and middle slopes of the Kanuku Mts. are characterised by Cordia alliodora, Centrolobium paraense, Apeiba schomburgkii, Acacia polyphylla, Pithecellobium s.l., Peltogyne pubescens, Manilkara spp., Cassia multijuga and Vitex spp. Manikara dominates the higher areas. Low forest/woodland with Erythroxylum and Clusia on slopes with bare rock.

The South Rupununi Savannah, in particular, has rock outcrops with a typical ‘rock vegetation’. The species present on the smallest rock plates are: Cereus hexagonus, Melocactus smithii, Cnidoscolus urens, Cyrtopodium glutiniferum and Portulaca sedifolia.

1.8 Complex of mixed forest and swamp forest in south Guyana

Large stretches of this type occur in SW Guyana between the upper reaches of the Oronoque and New Rivers. The forest is characterised by high occurrence of Geissospermum, Pterocarpus and Eperua.
 
 

2 Forests on excessively drained white sands

2.1 Clump wallaba forest

Clump wallaba forest, dominated by Dicymbe altsonii and D. corymbosa with co-dominance of Eperua, Catostemma and Hyeronima is found on excessively drained white sand ridges in the Mazaruni basin.

2.2 Clump wallaba/wallaba forest

In the upper Mazaruni basin Dicymbe corymbosa and Eperua spp. dominate nearly all forests on white sand. Chamaecrista and Micrandra are common co-dominants.

2.3 Wallaba forests (dry evergreen forest)

Dry evergreen forest on bleached white sands (albic Arenosols) occurs from the Pakaraima escarpment, through central Guyana and northern Suriname into a small narrow portion of French Guiana. Eperua falcata and E. grandiflora are strongly dominant and may form, alone or together, more than 60% of the canopy individuals. Common other species in the canopy layer are Catostemma fragrans, C. altsonii, Licania buxifolia, Talisia squarrosa, Ormosia coutinhoi, Eschweilera corrugata, Aspidosperma excelsum, Terminalia amazonia, Chamaecrista adiantifolia, Chamaecrista apocouita, Swartzia spp., Dicymbe altsonii (west Guyana only), D. corymbosa (ibid.), Manilkara bidentata (Pomeroon-Waini waterdivide) and Pouteria.

2.4 Forests on white sands in south Guyana

Very small patches of forests on white sand are found in south Guyana. In SW. Guyana Eperua is the most commonly found tree genus.

2.5 Dakama forest

Forest dominated by Dimorphandra conjugata (Dakama forest) is common on the higher parts of waterdivides from central Guyana to western Suriname. This forest type is characterised by very high standing litter crop (up to 800 ton/ha, Cooper 1982) and is very fire prone. Other species, characteristic for Dakama forests, are Eperua falcata, Talisia squarrosa, Emmotum fagifolium and Swartzia bannia. Humiria balsamifera (Muri) co-dominates the degraded Dakama forest and Dakama-Muri scrub with Dimorphandra.

2.6 Muri scrub/white sand savannah

In areas where fires are very regular or in flood-prone areas Dakama forest degrades into Muri-scrub, dominated by Humiria balsamifera. Other common species in this scrub are Swartzia bannia, Clusia fockeana, Licania incana, Bombax flaviflorum, Ocotea schomburgkiana, Trattinickia burserifolia, Ternstroemia punctata and Byrsonima crassifolia.
 
 

3 Swamps, swamp- and marsh forests

3.1 Open swamps

Herbaceaous and grass swamps in brackish and sweet water with Cyperus, Montrichardia, Commelina, Paspalum and Panicum.

3.2 Marsh Forest

Mora excelsa forms extensive stands along the rivers on alluvial silt up to the confluence of Rupununi and Rewa rivers. Canopy associates of the Mora forest are Carapa guianensis, Pterocarpus officinalis, Macrolobium bifolium, Eschweilera wachenheimii, E. sagotiana, Clathrotropis brachypetala, C. macrostachya, Eperua falcata, E. rubiginosa, Catostemma commune, C. fragrans, Pentaclethra macroloba, Vatairea guianensis, Symphonia globulifera, Terminalia dichotoma and Tabebuia insigni.

The rivers in the savannah area are bordered by gallery forest, which is inundated during part of the year. Trees species such as Caryocar microcarpum, Macrolobium acaciifolium, Senna latifolia, Zygia cataractae and Genipa spruceana occur along all the rivers in S-Guyana. In the open savannah Mauritia is a dominating element in the landscape.

3.3 Coastal swamp forest

In permanently flooded, flat plains in the present coastal zone a low swamp forest is found. Characteristic species are Symphonia globulifera, Tabebuia insignis/fluviatilis, Pterocarpus officinalis and Euterpe oleracea. Species that can become locally dominant in this forest type in Guyana are Pentaclethra macroloba, Vatairea guianensis, Pterocarpus officinalis and Virola surinamensis. Manicaria saccifera is commonly found as a narrow belt along rivers. More inland the duration of flooding is less pronounced and forest composition is slightly different. Common species here are Symphonia globulifera, Virola surinamensis, Iryanthera spp., Pterocarpus officinalis, Mora excelsa, Pachira aquatica, Manicaria saccifera and Euterpe oleracea.
 
 

4 Mangrove forests

4.1 Mangrove forests

Mangrove forests occur in a narrow belt of a few kilometres wide along the coast and along the banks of the lower reaches of rivers. The mangrove forest along the coast consists mainly of Avicennia germinans, with occasional undergrowth of the salt fern, Acrostichum aureum. Rhizophora occupies the more exposed, soft silts in river mouths and shores. Where the water is distinctively brackish a third mangrove species can be found, Laguncularia racemosa. Further inland mangrove species mix with Euterpe oleracea palms and such trees as Pterocarpus officinalis.

 

5 Savannah

5.1 Lowland shrub and grass savannah

Lowland grass savannahs

Lowland savannahs, dominated by the grasses Trachypogon and Axonopus and the shrubs Curatella and Byrsonima are found mainly in the southern parts where the Pakaraima Mts. border the Rupununi and Rio Branco savannahs and are also scattered throughout the western part of the region. At slightly higher altitude Echinolaena and Bulbostylis are also typical. Savannahs on white sands have more sedges and also include more genera typical of the alpine meadows.

Lowland shrub savannah

Fire-climax savannah vegetation, which contains characteristic species such as: Curatella americana, Byrsonima crassifolia, Byrsonima coccolobifolia, Antonia ovata, Palicourea rigida, Tibouchina aspera and Amasonia campestris. The main grasses belong to the genera Trachypogon, Paspalum, Axonopus and Andropogon and the main sedges to the genera Rhynchospora and Bulbostylis
 
 

6 Highland open vegetation types

6.1 Xeromorphic scrub

Xeromorphic scrub is found throughout the Pakaraimas. Humiria, Dicymbe, Clusia and Dimorphandra are typical genera of this vegetation type.

6.1 Tepui scrub

At high altitudes tepui scrub is found - in Guyana only on Mts. Roraima and Ayanganna. Most characteristic genera are Bonnetia, Schefflera, Clusia, and Ilex.

6.2 Upland savannah

Uplands savannahs are very similar in composition to lowland savannahs. The upland savannahs on white sands have more sedges and also include more genera typical of the alpine meadows.

6.3 Alpine meadows

The alpine meadows are also a very rich and distinct formation within the Guyana Highlands. In Guyana it is only found in the upper reaches of the Kamarang R., Mt. Holitipu and Lamotai Mt., both along the lower Kamarang R. Grasses are usually not dominant but are replaced by Stegolepis spp.. Other common genera include Abolboda, Xyris, Orectanthe, Chalepophyllum, Lagenocarpus and Brocchinia.
 
 

7 Submontane and montane forests of the Pakaraimas

7.1 Submontane forests of the Pakaraima uplands

Submontane forests, from 500 – 1500m, are fairly similar in composition to the lowland forests surrounding them, with species from Dicymbe, Licania, Eschweilera, Mora, Alexa being common to dominant. On white sands Dicymbe, Dimorpandra, Eperua and Micrandra are the most characteristic genera. Dry submontane forest is characterised by Dicymbe jenmanii (endemic to the Kaieteur region), Moronobea jenmanii, Humiria balsamifera, Chrysophyllum beardii, Tabebuia spp., Anthodiscus obovatus, Saccoglottis, Dimorphandra cuprea and Clusia spp.

7.2 Upper montane forests of the Pakaraima highlands

Upper montane forests (1500-2000m) are only found on the high table mountains, such as Mts. Roraima, Ayanganna and Wokomung. Typical highland genera such as Bonnetia tepuiensis, Schefflera, Podocarpus, Magnolia and Weinmannia are found here. Low scrubs with Melastomataceae, Rubiaceae, Ilex and Podocarpus steyermarkii are also expected.

 

8 Submontane forests of south Guyana

8.1 Submontane forest of south Guyana

Submontane forest is found in the Acarai Mts from 600-800 m. The forest is quite similar to the forest in the Kanuku Mts. with Centrolobium, Cordia, Peltogyne, Vitex, Inga, Protium, Tetragastris, Parkia, Pseudopiptadenia, Spondias and Genipa. Forests on the mountain tops are dominated by Myrtaceae and Clusia on Sierra do Acarai
 

Literature cited and/or used:

Boggan, J., Funk, V., Kelloff, C., Hoff, M., Cremers, G. and Feuillet, C. (1997). Checklist of the plants of the Guyanas (Guyana, Surinam, French Guiana). 2nd edition. Centre for the Study of Biological Diversity, University of Guyana, Georgetown, Guyana.

Fanshawe, D.B. (1952). The vegetation of British Guyana. A preliminary review. Imperial Forestry Institute, Oxford, United Kingdom.

Fanshawe, D.B. (1961). Principal Timbers. Forest products of British Guiana part 1. Forestry Bulletin no. 1. Forest Department, Georgetown, Guyana.

Huber, O. (1995a). ‘Vegetation’, pp. 97-160 in P.E. Berry, B.K. Holst and K. Yatskievych (eds.), Flora of Venezualan Guayana. Volume 1, Introduction. Missouri Botanical Garden, St. Louis, USA.

Huber, O., et al, (1995). Vegetation Map of Guyana. Centre for the Study of Diversity, Georgetown, Guyana.

Huber, O. (1997). Pantepui Region of Venezuela’, pp. 312-315 in S.D. Davis, V.H. Heywood, O. Herrera-McBryde, J. Villa-Lobos and A.C. Hamilton (eds.), Centres of plant diversity. A guide and strategy for their conservation. Volume 3. The Americas. WWF, IUCN, Gland, Switzerland.

de Milde, R. and de Groot, D. . (1970a). Reconnaissance survey of the more accessible forest areas. UNDP/FAO, Georgetown, Guyana.

de Milde, R. and de Groot, D. . (1970b). Reconnaissance survey of the more accessible forest areas. Zone 1. UNDP/FAO, Georgetown, Guyana.

de Milde, R. and de Groot, D. . (1970c). Reconnaissance survey of the more accessible forest areas. Zone 2. UNDP/FAO, Georgetown, Guyana.

de Milde, R. and de Groot, D. . (1970d). Reconnaissance survey of the more accessible forest areas. Zone 3. UNDP/FAO, Georgetown, Guyana.

de Milde, R. and de Groot, D. . (1970e). Reconnaissance survey of the more accessible forest areas. Zone 4. UNDP/FAO, Georgetown, Guyana.

de Milde, R. and de Groot, D. . (1970f). Reconnaissance survey of the more accessible forest areas. Zone 5. UNDP/FAO, Georgetown, Guyana.

de Milde, R. and de Groot, D. . (1970g). Reconnaissance survey of the southern part of Guyana. UNDP/FAO, Georgetown, Guyana.

ter Steege, H. (1998). The use of forest inventory data for a National Protected Area Strategy in Guyana. Biodiversity and Conservation 7: 1457-1483.

Steege, H. ter, Lilwah, R, Ek, R.C., Hout, P. van der, Thomas, R.S., Essen, J. van and Jetten, V.G. (2000). Composition and diversity of the rain forest in Central Guyana. An addendum to ‘Soils of the rainforest in Central Guyana’. Report 2000-1. The Tropenbos-Guyana programme, Georgetown, Guyana.

ter Steege, H. (ed.) (2000). Plant diversity in Guyana. With recommendations for a National Protected Area Strategy. Tropenbos Series 18. The Tropenbos Foundation, Wageningen, The Netherlands.

ter Steege and Zondervan (2000). A preliminary analysis of large-scale forest inventory data of the Guiana Shield: pages 35-54 in ter Steege (ed.) Plant Diversity in Guyana. Tropenbos Series 18. Tropenbos Foundation, Wageningen, The Netherlands

Welch, I.A. (1974). Forests of the Chidago Reservoir area, Upper Mazaruni. Forest Department, Georgetown, Guyana.

Welch, I.A. (1966). Report on field trip to the North West District. Forest Department, Georgetown, Guyana.

Welch, I.A. (1966). Barama-Cuyuni-Kamarang forest reconnaissance. Forest Department, Georgetown, Guyana.

Welch, I.A. and Bell, G.S. (1971). Great Falls Inventory. Forest Department,  Georgetown, Guyana.

 

List of Acronyms used

GINRIS - Guyana Integrated Natural Resources Information System

NARI - National Agricultural Research Institute

GFC - Guyana Forestry Commission

FIDS - Forest Industries Development Survey (FAO)

JERS - Japanese Earth Resource Satellite

NRMP - National Resources Management Project

FAO - Food and Agricultural Organisation

The Map


 

Note: Copies of Dr ter Steege’s full report are available from GFC.  1:1,000,000 scale copies of the National Vegetation Map (A0 size) will be available shortly from the GFC Forest Resources Information Unit.

 

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