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.
