 |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Of the one billion people in the humid tropics, perhaps a fifth live in or adjacent to forests. To provide fuelwood and charcoal for their daily needs, these 200 million people fell acres of trees each year. In addition, much fuelwood is cut for shipment to urban markets. Together with commercial timber logging and expansion of agriculture, the result is depletion of tropical forests at a rate that exceeds any present attempts to replenish them.
This study, the second of two volumes, is concerned with ways of establishing self-replenishing sources of fuelwood. In some countries trees are already being profitably cultivated in energy plantations, and the idea has become more attractive as the price of other fuels rises.
Conditions in the humid tropics promote the growth of many kinds of trees and shrubs, with the heat and dampness ensuring high rates of photosynthesis and short harvest cycles. The question is, which trees are the best candidates for deliberate cultivation?
The first volume of this report described the following species as worth testing for fuelwood crops in the humid tropics:
|
Acacia auriculiformis |
Mangroves |
| | |
|
Calliandra calothyrsus |
Mimosa scabrella |
| |
|
|
Casuarina equisetifolia |
Muntingia calabura |
| |
|
|
Derris indica |
Sesbania bispinosa |
| |
|
|
Gliricidia septum |
Sesbania grandiflora |
| |
|
|
Gmelina arborea |
Syzygium cumini |
| |
|
|
Guezuma ulmifolia |
Terminalia catappa |
| |
|
|
Leucaena leucocephala |
Trema spp |
This section of the present volume describes further shrub and tree species that hold promise for cultivation in humid tropical regions both for profit and for staving off the threat of fuelwood depletion in developing tropical countries.
Species included in other sections of this volume that are worth testing in the humid tropics are Melaleuca quinquenervia and Robinia pseudoacacia.
Botanic Name
Albizia falcataria (L. ) Fosberg
Synonyms
Albizzia falcata (L.) Backer, A. molluccana Miq.
Common Names
Batai, Molucca albizzia, Moluccan sau,
djeungjing, sengon, falcata, vaivai, puah, white albizzia, kayu macis, tamalini,
mare, placate, plakata
Family
Leguminosae (Mimosoidae)
Main Attributes
Because of its rapid growth, vigorous
coppicing, and usefulness when grown in combination with agricultural crops, it
should be considered for firewood, notwithstanding its low specific gravity and
low caloric value. In some regions like Western Samoa and Java the species is
already used as fuelwood.
Description
One of the fastest growing of all trees, Albizia
falcataria reaches (under favorable conditions) 15 m in height in 3 years, 30 m
in 10 years, and 44 m in 17 years. When grown in the open, its crown spreads to
form a large umbrellashaped canopy, but in plantations it has a narrow crown.
Its flowers are creamy white and have a slight fragrance.
Distribution
Albizia falcataria is native to Papua New
Guinea, West Irian, the Solomon Islands, and the Moluccas. The species is grown
in plantations, notably in the Philippines and elsewhere in Southeast Asia and
in Fiji. It has also been used in variety trials in India, Sri Lanka, Taiwan,
and Western Samoa. It is now naturalized in many urban areas of Sabah. On Java,
especially west Java, it is planted in home gardens and gardens mixed with
herbaceous and tree crops (for example fruit trees) as a source of timber and
firewood. The practice is quite widespread in the area and can yield a
substantial income for villagers.
Use as Firewood
The wood is light, soft, and lacks strength
(specific gravity 0.24-0.49). Tests performed in Java show that it makes good
charcoal and that its caloric potential varies from 2,865-3,357 kcal per kg.
Yield
On better soils growth can be up to 50 m3 per ha per
year, while average sites yield up to 39 m3 per ha per year on a 10-year
rotation. (Growth tends to culminate at or before 10 years.)
Other Uses
· Wood. The wood is excellent for fiber board
and particle board. It is also used as veneer core stock and for pallets and
crating, furniture components, matches, and boxes.
· Pulp. The species is most suitable for ground wood pulp because of its low density, pale color, and fiber length and qualities. In the Philippines it is successfully used for newsprint.
· Shade. Albizia falcataria is widely used as a shade tree for cattle and for cocoa, coffee, banana, and tea plantations.
Environmental Requirements
· Temperature. Albizia
falcataria requires a temperature range of 22°-29°C.
· Altitude. Within its natural range, this species occurs up to 1,000 m elevation. It is grown at altitudes up to 1,500 m, but generally does best in plantations below 800 m.
· Rainfall. This tropical species thrives in humid tropical climates with no more than a slight dry season (0-2 months). The best Philippine growth has been achieved on sites with an annual rainfall of 4,500 mm and no dry period.
· Soil. Albizia falcataria does best on welldrained, deep soils with reasonably high fertility. Like some other legumes, it is likely to perform better on slightly alkaline than on acid soils.
Establishment
The tree regenerates easily by natural seeding
on any clearing. It produces seeds prolifically and regularly from an early age,
usually from 3 to 4 years on.
· Seed treatment. Best germination occurs after mechanical scarification or treatment with sulfuric acid for 12 minutes followed by water for 15 minutes. Seed may also be placed in boiling water, removed from heat, and wrapped in wet cloth for 24 hours.
· Ability to compete with weeds. Remarkably fast initial growth is typical of Albizia falcataria; therefore, weeding normally can be limited to one complete weeding and three spot weedings during the first year after planting. Occasional elimination of vines may be necessary after that.
Pests and Diseases
Various white and brown rots are the most
serious diseases afflicting Albizia falcataria plantations. These diseases
normally follow wind damage. Plantings in the Philippines are subject to attack
by the fungus Coiticum salmonicolor, causing "albizia canker," which can be
devastating unless controlled with Bordeaux mixture or other fungicides. Harmful
insects are Eurema blanda, Eurema hecabe, Semiothise spp., Xystocera festiva
(wood borer), and Penthicodes jarinosa.
Limitations
Albizia falcataria is extremely susceptible to
uprooting and breakage of branches by high winds. Once exposed, the low-density
wood is easily attacked by fungi, which bring about rotting of the trees. The
tree has a massive root system that is known to contribute to soil erosion, and
it should not be planted on steep hillsides. Large tree roots, rather than
holding the soil, have an opposite effect. Grass and herbaceous plants are soil
retainers.
Botanic Name
Bursera simaruba Sarg.
Synonyms
Bursera gummifera L., B. ovalifolia Engler,
Elaphrium simaruba Rose
Common Names
Gumbo limbo, gum-elemi, gumtree, West Indian
birch, red birch, almacigo, indio desnudo, palo mulato, galo de incienso,
turpentine tree, and many others
Family
Burseraceae
Main Attributes
This handsome tree is esteemed for fuel and
for living fence posts throughout Central America and the Caribbean. So far,
however, it is virtually unknown elsewhere. It is easily propagated - green
branches thrust into the ground take root quickly and grow vigorously. The trees
regenerate swiftly after cutting. In fact, even trees blown down by winds send
up shoots, which soon become trunks as big as the original.
Description
The gumbo limbo as it grows in forests is an
erect, straight, resinous tree reaching 20-30 m, with a stout trunk (to 75 cm)
that is often forked about 2 m from the ground, forming thick vertical branches
that fork again higher up. The bark, which peels off in thin flakes, is
typically copper colored (sometimes silvery) and glossy. When growing in the
open, the branches spread and form a broad crown. The tree is bare during the
cool, dry season. The leaves are compound and have a turpentine odor when
crushed.
Distribution
This handsome tree is native to and esteemed in
areas from central Florida through the Bahamas and West Indies and from southern
Mexico to the northern parts of South America.
Use as Firewood
The wood has a high moisture content, but
when thoroughly dry it is commonly burned as firewood and charcoal. Because of
its flammability, Indians of Yucatan use it for kindling. The wood has a
specific gravity, green and oven dried, of 0.30-0.40.
Yield
No studies have been made of the potential firewood
yield. In Belize, surveys have shown populations of up to 57 trees per ha in the
wild.
Other Uses
· Wood. The wood seasons well, with slight
shrinkage; is easily worked; saws, planes, and polishes satisfactorily; holds
nails firmly; and is used commercially for a veneer that resembles
paper
birch and for plywood for interior use. It is fairly strong, but is not durable
for outside use, being attacked by borers, beetles, and termites. Locally, it is
made into boxes and crates, soles for sandals, light furniture, and matchsticks
and toothpicks.
· Beautification. The gumbo limbo is much used as an ornamental. In southern Florida it is planted as a landscape tree in new developments and along streets, mainly because of its quick growth, but also because of the newly awakened appreciation of native species. It has long been planted as a living fence throughout the Caribbean area.
· Resin. The aromatic resin, which oozes from an incision as a thick, amber gum, is concentrated and dried and the chips offered as tithes or burned as incense in South American churches.
Environmental Requirements
· Temperature. Gumbo limbo
requires a subtropical or tropical climate. Fully grown trees stand occasional
brief winter frosts.
· Altitude. It is found from sea level to 1,800 m elevation in Guatemala, but generally occurs below 1,000 m.
· Rainfall. The tree abounds where annual rainfall averages 500-1,400 mm.
· Soil. Gumbo limbo endures extreme soil types ranging from fertile, moist forest habitats to dry, barren limestone, but it grows best in rich lowlands. Under the severely arid conditions of some Caribbean islands it is rather stunted and crooked, but survives. It has a high degree of salt tolerance.
Establishment
While the tree reseeds itself in its natural
areas, it is seldom deliberately propagated by seed.
· Ability to compete with weeds. Being a forest tree, the gumbo limbo tolerates shade at all stages of growth. It is not retarded by the shade of competing vegetation even in the juvenile period.
Pests and Diseases
The resin is a natural insect repellent,
and no pests or diseases are reported in available literature.
Limitations
Apart from cold sensitivity, the handicaps seem
to be only the brittleness of branches, which may be snapped off by strong gusts
of wind; the perishability of exposed wood; and the discoloration of the timber
by the sap-stain fungi to which it is prone because of its high moisture
content. (Such staining can be avoided by immediate kiln drying or by immediate
spraying of the cut logs with a
fungicide.)
Botanic Name
Coccoloba uvifera (L.) L.
Synonyms
Coccolobis uvifera Jacq., Polygonum uvifera L.
Common Names
Seagrape, seaside grape, bay grape, baya de
praga, mangle de falda, raisin la mer, uva de mar, uva de playa, uva caleta,
uvero, horsewood, hopwood
Family
Polygonaceae
Main Attributes
Seagrape is one of the first woody species to
become established on sandy shores, being more hardy in these exposed places and
more tolerant of salt than most trees.
Description
Fully exposed on windswept seacoasts, the
seagrape is dwarfed and bushy (to 2.5 m high) and forms dense colonies. On
leeward shores and inland locations it becomes a roundtopped, spreading,
low-branching tree up to 15 m high, with thick, smooth branches and a stout
trunk to 1 m in diameter. The stiff and leathery leaves are large, thick, and
almost circular. They turn scarlet or yellow and drop off in the winter dry
season, but they are soon replaced by silky new growth with a bronze hue. Small
and fragrant white flowers are borne profusely in spring and develop into
red-purple grapelike clusters of velvet-skinned edible fruits. Male and female
flowers are borne on separate trees.
Distribution
The seagrape is native to southern Florida,
Bermuda, the Bahamas, and West Indies. It also grows from the northeast coast of
Mexico along the Atlantic coast of Central America, reaching down both coasts of
South America as far as Peru and Brazil. It is often planted as a seashore
windbreak in the Hawaiian Islands. It was introduced into the Philippines and
Zanzibar about 40 years ago.
Use as Firewood
Throughout its range, the wood is commonly
employed as firewood and for making charcoal. In Mexico the charcoal has been
particularly prized by blacksmiths and silversmiths. In an ignition trial, small
dry branches and twigs were lit with matches. The first flames gave off a little
smoke; within 5 minutes there were red coals and only wisps of smoke; and in
another 5 minutes there were bright, smokeless, even flames whose intense heat
surpassed the maximum 204°C on a thermometer held 40 cm above the fire,
proving the seagrape to be ideal for cooking. Its specific gravity is reported
to be from 0.7 to 0.96.
Yield
The seagrape is fast growing, multistemmed if pruned,
and profusely branched. Yield should be exceptional, though no statistics are
available.
Other Uses
· Wood. The wood is fine "rained, compact,
heavy, and hard. It takes a high polish and is valued for furniture and
cabinetwork, but is subject to dry-wood termites.
· Ornamental. The seagrape is widely grown as an ornamental tree and is a great favorite for Florida landscaping in even the most sophisticated sites, either free form or trimmed to a globular head. It is also close planted and trimmed as a hedge. It flourishes inland as well as in coastal locations and is long lived.
· Fruit. The fruits are popular in the Caribbean, where they are sold by street vendors and in local markets. They make excellent jelly.
· Honey. The flowers yield abundant nectar, and the honey, though high in moisture, is of good quality, light amber in color, and spicy.
· Bark. The bark is rich in tannin. In the past, the red-brown evaporated decoction of the wood and bark, called king, was regularly exported to Europe for use in tanning and dyeing.
Environmental Requirements
· Temperature. The seagrape
requires a subtropical or tropical, climate. It does need full sun.
· Altitude. In the Philippines the tree grows well from sea level to an elevation of 500 m. In Florida it occurs up to the central part of the peninsula, and it has withstood brief freezes that have killed mature mango trees.
· Rainfall. Throughout its range, the seagrape is subject to great variations in annual precipitation, from the 1,400-mm Florida average to the 500-mm average of the near-arid islands of the Caribbean.
· Soil. The seagrape is remarkable in its ability to thrive in nearly pure sand and on rocky coasts, as well as in marl, oolitic limestone, and diabase, dry or wet, but with good drainage. It is extremely tolerant of salt.
Establishment
Seeds germinate readily, but a seedling
seagrape may not fruit for 6-8 years. Vegetative propagation is preferred
because it is quicker and is the only way to assure reproduction of female trees
or selected cultivars. Air layering, ground layering, and grafting are
practiced, but mature wood cuttings are most commonly employed for mass
multiplication.
· Seed treatment. None required.
· Ability to compete with weeds. The seagrape cannot tolerate shade; therefore, seedlings should be weeded until they outgrow competition. For this reason, cuttings are more practical because they become established quickly and outdistance the weeds.
Pests and Diseases
In Hawaii, seagrapes planted inland are
attacked by the rose beetle Adoretus sinicus. Generally, the seagrape is
virtually free of pests and diseases, but occasionally, under adverse
conditions, the leaves are affected by rust or fungal or algal leaf spots, and
there have been reports of mushroom root rot.
Limitations
The seagrape is not adapted to extremely hot and
humid environments. It needs full sun, low altitudes, and mild winter weather
where only brief frosts may occur. Leaf fall may be a nuisance in cold dry
seasons.
Botanic Name
Eucalyptus brassiana S. T. Blake
Common Names
Cape York red gum, gumtopped peppermint
(Queensland); karo (Papua New Guinea)
Family
Myrtaceae
Main Attributes
Eucalyptus brassiana is a hardy, fast-growing
tree adapted to a variety of site conditions in the lowland tropics. It
tolerates periodic flooding and readily coppices.
Description
The tree often grows from 7 to 15 m high on
infertile sites but reaches more than 30 m on better sites. The trunk may be
moderately straight for half the tree's height, but is often badly shaped.
Typically, it divides into several large ascending branches.
Distribution
A tropical eucalypt, Eucalyptus brassiana occurs
in southwestern Papua New Guinea and on Cape York Peninsula in Queensland,
northern Australia, between latitudes 8° and 16° S. The best
development is on lowland sites in Papua. It has recently been introduced to
several subhumid to humid tropical areas.
Use as Firewood
Eucalyptus brassiana is a fastgrowing species
with the capacity to produce coppice shoots. The wood is moderately dense,
probably similar to that of Eucalyptus camaldulensis.
Yield
Trees in experimental plots in Malaysia have reached as
high as 7.6 m, with a diameter of 6.3 cm at 2.5 years of age. In Bangladesh the
tree's growth rate is similar to that of Eucalyptus camaldulensis, while it has
shown average-togood growth rates in trial plots in Vietnam, parts of East and
West Africa, and Brazil.
Other Uses
· Wood. The brown or pale reddish brown
heartwood is hard, heavy, strong, and durable. Because the natural stands occur
in areas of low population density, the timber has been used very little. On
Daru Island, Papua New Guinea, it is regarded as an excellent building timber
for general construction and posts.
Environmental Requirements
· Temperature. In Queensland
and Papua New Guinea, the natural habitat of the species, the climate is
tropical and humid to subhumid. The trees withstand high temperatures, since the
mean maximum temperature of the hottest month is around 32°C. Frosts have
not been recorded, and the seedlings are likely to be frost-sensitive.
· Altitude. The natural stands occur at low altitudes from sea level to 650 m.
· Rainfall. In its native habitat the tree tolerates a dry season lasting from 3 to 5 months; the minimum annual rainfall is 1,000 mm.
· Soil. The species grows from well-drained rocky slopes to undulating plains and on seasonally inundated flats and depressions. The soils are typically infertile. It has grown well on the margins of rice fields in Bangladesh.
Establishment
Eucalyptus brassiana regularly produces good
seed crops. Seed germination is high, and the seeds are long lived when kept
sealed and dry in cold storage. The plantable stock raised in the nursery is
likely to be about 25 percent of the viable seeds sown. The seedlings can be
raised in trays and transplanted into containers or sown directly in containers.
Under favorable conditions, plantable seedlings can be produced within 6-10
weeks after sowing.
· Seed treatment. None required.
· Ability to compete with weeds. Poor. Rapid initial growth is dependent on complete weeding during the first year.
Limitations
There is little experience with planting this
species in large areas, and its silvicultural requirements are not well known,
but it must be kept free of weeds during the establishment phase. Provenance
trials are required to determine the optimum seed sources.
Related Species
The tree is related to the wellknown fuelwood
species Eucalyptus tereticornis and Eucalyptus camaldulensis, and to Eucalyptus
exserta, which is widely planted in the People's Republic of
China.
Botanic Name
Eucalyptus deglupta Blume
Synonym E. naudiniana F. Muell.
Common Names
Kamarere (Papua New Guinea); bagras
(Philippines); leda (Indonesia)
Family
Myrtaceae
Main Attributes
Kamarere is one of the world's fastest
growing trees. It is capable of colonizing land eroded by landslides and areas
of recent volcanic activity.
Description
This is a large tree, generally reaching from 35
to 60 m high but occasionally reaching up to 75 m, with diameters of 0.5-2 m or
greater. On unstable soils and river alluvia the tree often develops buttresses
3-4 m high. The trunk is one-half to two-thirds of the tree height and is
typically straight.
Distribution
A wholly tropical eucalypt, kamarere has a
markedly discontinuous distribution that includes Mindanao in the Philippines;
Sulawesi, Ceram, and lrian Jaya in Indonesia; and parts of the mainland and New
Britain in Papua New Guinea. The best development occurs on riverine banks at
altitudes mainly below 150 m in New Britain. The species has been introduced to
many humid tropical areas.
Use as Firewood
The main use of Eucalyptus deglupta is as a
pulpwood. It is normally considered too valuable for use as firewood. However,
it grows so quickly that in suitable fuel-short areas it could be considered for
both uses. Its wood has a specific gravity of 0.40-0.80. Trees greater than 15
years of age yield good charcoal.
Yield
Test plots in Papua New Guinea suggest that in 15
years' time it may reach 44 m in height, with a diameter at breast height of 54
cm. Yields of 20-40 m3 per ha per year are common to that age in several
countries.
Other Uses
· Wood. The wood from natural stands has been
used for heavy construction, furniture, and flooring. Shrinkage and fibre
collapse have been slight,
· Pulp. Pulps of good yield have been obtained using the sulfate process.
Environmental Requirements
· Temperature. Kamarere's
native climate is subequatorial in coastal areas and tropical else where. Near
sea level the mean maximum temperature of all months may be 30°-32°C,
but al higher altitudes the mean maximum of the coolest month may be only
24°C.
· Altitude. It is found from sea level to about 1,800 m.
· Rainfall. The mean annual rainfall is mainly 2,500-3,500 mm in its native habitat, but there is no upper limit for planted stands on well-drained sites.
· Soil. The tree grows best on deep' moderately fertile sandy loams, but also occurs on soils derived from volcanic ash and pumice. Although most stands occur on alluvium along rivers, landslides and volcanic disturbances provide sites for small stands inland.
Establishment
Under plantation conditions, kamarere flowers
at an early age, usually by 3-4 years. Normally, the seedlings are field planted
as tubed stock.
· Seed treatment. None required. The seed germinates quickly and subsequent seedling growth is usually fast.
· Ability to compete with weeds. The planting fields for kamarere must be weeded for the first 6 months and some weeding is necessary until the end of the second year.
Pests and Diseases
In both natural stands and plantations,
termites are the most serious pests of Eucalyptus deglupta. Young trees in
Malaysia have been damaged severely by the cossid moth Zeuzera coffeae and a
ring bark borer (family Hepialidae). Tip dieback of young trees in the Solomon
Islands is caused by the coreid bug. Ant control must be continuous in Brazil.
Trees of some provenances have been attacked by a stem and bark borer (Agrilis
spp) in Papua New Guinea and the Philippines.
Limitations
The bark is very thin and the tree is sensitive
to fire, susceptible to frost damage, and intolerant of drought. Young trees in
particular are brittle and easily damaged by strong winds, thereby decreasing
the viability of seed. Kamarere usually does not
coppice.
Botanic Name
Eucalyptus pellita F. Muell.
Synonym
E. spectabilis F. Muell.
Common Name
Red mahogany, red stringybark, large-fruited red
mahogany, Daintree stringybark
Family
Myrtaceae
Main Attributes
Red mahogany grows quickly in humid and
subhumid tropical lowland regions. Good provenances from the Cape York Peninsula
could provide the basis for important new eucalypt trials in tropical countries.
Description
Red mahogany is a medium to large tree, usually
20-25 m in height but exceeding 35 m under favorable conditions. At its best its
trunk grows straight up to half the tree height, with a large, heavily branched
crown. On bare rock above beaches it may be reduced to a bushy shrub.
Distribution
This eucalypt occurs on lower coastal slopes of
Australia. Northern populations occur from near the top of Cape York Peninsula
to between Cairns and Townsville (latitude 12°-18°S) and southern ones
from near Brisbane to the Batemans Bay area in southern, coastal New South Wales
(27°-36°S).
Use as Firewood
The tree has a high density (990 kg per m3)
suitable for charcoal and fuelwood.
Yield
In Espirito Santo, Brazil, a northern provenance
reached a mean height of 13.7 m and a diameter of 12.6 cm in 3.5 years. In Minas
Gerais State, the same provenance was 14.9 m tall with a diameter of 13.3 cm at
the same age.
Other Uses
· Wood. The heartwood is moderately heavy,
strong, and durable in and out of the ground. Although the grain is somewhat
interlocked, the wood is not difficult to work. It has a wide range of uses for
building and heavy ornamental work.
· Honey. The flowers are a minor source of thin, strong-flavored honey from January to February in Queensland. They provide large quantities of pollen for the bee colonies.
Environmental Requirements
· Temperature. Red mahogany
is found main ly in the humid climatic zone. The mean maximum temperature of the
hottest month varies from 24° to 33°C and the mean minimum of the
coolest from 6° to 16°C; frosts are absent or occur less frequently
than five times a year.
· Altitude. From sea level to about 750 m.
· Rainfall. The mean annual rainfall in the tree's natural Australian habitat is 900-2,30C mm.
· Soil. The tree grows mainly on gentle-to. moderate topography, though it is found to a km. ited extent on steep, well-drained slopes. It prefers moist sites - the lower slopes of large ridges and even alongside small streams in the drier and hotter parts of its occurrence. Soil types range from shallow sandy podsols derived from sand. stone to deep forest loams. However, red mahogany is recommended for planting only in well. drained, sandy soil.
Establishment
· Seed treatment. No pretreatment is
required. The seeds remain viable for many years under controlled storage
conditions.
· Ability to compete with weeds. Once established, the tree forms a dense crown that shades out weeds at an early stage.
Pests and Diseases
Eucalyptus pellita is moderately resistant
to the stem canker Cryphonectria cubensis (Bruner) Hodges.
Limitations
In areas other than Australia where it has been
grown, Eucalyptus pellita's growth rate has not been good enough to demonstrate
an advantage over the better-known Eucalyptus resinifera. However, these results
appear to be based largely on the southern provenances. Northern provenances
have grown well in moist tropical areas, especially in
Brazil.
Botanic Name
Eucalyptus urophylla S. T. Blake
Synonyms
E. decaisneana, also erroneously referred to as E.
alba
Common Names
Ampupu, Timor mountain gum
Family
Myrtaceae
Main Attributes
Eucalyptus urophylla shows promise in
tropical or subtropical countries where the rainfall exceeds 1,000 mm annually.
It is highly resistant to the stem canker Cryophonectria cubensis (Bruner)
Hodges, which has caused serious losses to eucalypts in Latin America.
Description
On favorable sites this species can exceed 50 m
in height, with diameters of up to 2 m and straight clear boles for half or
two-thirds of the tree height. There is considerable variation within the
species in the degree of retention of rough bark, ranging from only a short
stocking to boles fully clothed in rough fibrous bark.
Distribution
Eucalyptus urophylla occurs in Timor and other
Indonesian islands. It was introduced into Brazil in 1919 under the name
Eucalyptus alba, and the progeny from this introduction were used to establish
large areas of plantations. The progeny were mainly hybrid stock, and these
trees have become known as "Brazil alba." The pure species has grown extremely
well in Brazil, Cameroon, Ivory Coast, and the People's Republic of Congo and is
showing considerable promise in areas in Southeast Asia and the Pacific where
there is a distinct but not too severe dry period in the cool season.
Use as Firewood
Although one of the less dense eucalypts,
young trees make a satisfactory fuelwood. It coppices well.
Yield
Yields of 20-30 m3 per ha per year have been reported
under favorable growing conditions. Low-altitude provenances have usually given
the highest yields.
Other Uses
· Wood. The wood of older trees is used in
heavy construction, building poles, and fence posts and gives a high pulp yield.
Environmental Requirements
· Temperature. Mean monthly
temperatures range from 18 ° to 28 °C in Eucalyptus urophylla's
natural habitat.
· Altitude. This is primarily a mountainous species, growing at altitudes from 300 m to almost 3,000 m.
· Rainfall. The rainfall can be as low as 1,300-1,400 mm, but the tree does best with rainfall of 2,000-2,500 mm.
· Soil. This eucalypt grows best on deep, moist, free-draining, medium-to-heavy soils derived from noncalcareous rock.
Establishment
The species seems to grow best under nursery
conditions. In one trial in Costa Rica, seedlings were transplanted 55 days
after sowing to polyethylene bags containing loamsand mixture. In northeast
Brazil the seedlings are grown in polyethylene bags in the nursery. They reach
an optimum size of about 25 cm in 75 days. A technique to raise Eucalyptus
urophylla and a hybrid of Eucalyptus urophylla x Eucalyptus grandis vegetatively
by cuttings has been developed in Brazil and the Congo.
· Seed treatment. None required.
· Ability to compete with weeds. The tree is highly sensitive to competition in the early stages, and the plantation must be kept weed free for 612 months after planting. After that time, the dense crown inhibits competing weeds.
Pests and Diseases
Eucalyptus urophylla is susceptible to
termite attack. In Australia defoliation by a range of insects has reduced the
growth considerably. The trees are resistant to the canker disease in Brazil.
Leaf-cutting ants, Atta spp. and Acromyrmex spp., can be a problem in parts of
South America; control measures are essential where the ants are present.
Limitations
Seeds are not yet readily available from
plantations or natural forests however, a seed orchard has been planted in the
Congo.
Botanic Name
Hibiscus tiliaceus L.
Synonyms
Pariti tiliaceum Britton, Paritium tiliaceum St.
Hill
Common Names
Mahoe, majagua, majagua de playa, sea hibiscus,
seaside mahoe, emajagua, hau, among others
Family
Malvaceae
Main Attributes
The wood of this fast-growing tree is used
chiefly for fuel, although the fibrous bark is much used for cordage. The trees
sprout from stumps and, when cut back, produce long, vigorous shoots from which
quantities of rope can be made.
Description
The mahoe is an evergreen that may grow 12 m
tall. Normally, it has a short trunk and a broad, rounded crown. In wetlands it
is branched close to the ground, forming a low and sprawling massive mound. The
lowest branches bend down, take root, and put forth new growth, thus forming
extensive tangled thickets. The handsome leaves are somewhat heart shaped.
Distribution
The mahoe is pantropic, growing just inshore of
the mangroves on the coastal fringe and extending up estuaries and rivers.
Use as Firewood
In Puerto Rico, India, and Malaya, the wood
is used principally for fuel; it is also employed as firewood in Ghana. In
Malaya, the tree is recommended for planting on poor soils as a firewood
resource. In American Samoa and other Pacific islands, it is prized for making
fire by friction because it ignites readily when a hardwood stick is twirled
rapidly against it. In the past, in Hawaii, oiled sticks of mahoe wood were set
afire and thrown from cliffs in quick succession as "fireworks." The wood has a
specific gravity of 0.6.
Coppicing is remarkably swift and profuse, with multiple long stems arising from cut stumps.
Yield
No systematic study has been made of the productivity
of mahoe for firewood. Its rapid growth and spreading habit, however, augur well
for high volume per hectare.
Other Uses
·Wood. The tree has been of such inestimable
value to Pacific seafarers that it was formerly necessary to obtain permission
before cutting a single branch. The heartwood is yellowish or purplish, light
but firm, flexible, porous, close "rained, easy to work, and takes a high
polish. Durable in salt water, it is popular for fishing-net floats, floats for
outriggers and for light boats, planking, and pilings for dwellings in wetlands.
It is also used for laths for huts and for tool handles and cabinetwork. It has
been pulped for papermaking, but the product is of low quality because of the
wood's short fibers and is fit only for wrapping purposes.
· Bark. The bark has always been used for making rope and twine; for long, strong cables for hauling logs and ships; for harpoon lines and fish traps; and for mats, household strainers, tape cloth, and hula skirts. Easily stripped from the branches in long ribbons, its rough outer surface is peeled off, leaving a smooth surface. When reduced to fiber, it is similar to jute. It is stronger wet than dry.
· Erosion control and dune fixation. The mahoe is ofen planted to stablize sand dunes and, on muddy shores, to trap soil to reinforce the coastline. In India it is planted to prevent erosion on the banks of rivers and reservoirs.
· Beautification. The mahoe is widely valued as an ornamental because of its lush foliage and attractive flowers. On high, well-drained land it becomes an elegant landscape plant with a symmetrical, rounded head and clear trunk, providing it is "raised up" by pruning the base when the tree is young. Enough space must be available for development of its form; this is not a tree for small gardens. It is sometimes close planted as a living fence.
Environmental Requirements
· Temperature. The species is
adapted to warm, humid areas, from near-tropical (for example southern Florida)
to ultratropical.
· Altitude. The mahoe grows from sea level to 500 m elevation.
· Rainfall. It thrives where there is annual precipitation of 1,400 mm. Some scattered specimens are found on the coasts of extremely dry regions.
· Soil. The tree has no particular soil requirements; it seems to grow equally well in mud, marl, sand, and limestone, assuming greater stature on high, dry sites inland than in its native habitat - shallow brackish swamps. It is highly salt tolerant.
Establishment
The seed capsules may float for months until
they reach favorable shores, where the seeds readily germinate and colonize the
area. In cultivation the tree is easily raised from seed or cuttings, or by air
layering. Growth is rapid; in 2-3 years the tree is large enough to provide
shade.
· Ability to compete with weeds. Seedlings should be weeded in the early stages if planted inland. If planted in swampy, saline sites, there will be little vegetative competition and they will be self-sustaining.
Pests and Diseases
The mahoe is an extraordinarily healthy
tree with few problems. Spring and summer wilting was observed at Lahore, India,
and attributed to Alternaria dianthi, which is locally prevalent on other
plants. The tree recovers by the following season without treatment. In Florida
it is sometimes affected by leaf spot caused by Gloeosporium spp or Phyllosticta
hibiscina.
Limitations
The mahoe is limited to warm, humid, low
elevations. It is intolerant of cold, though mature trees have not been
seriously injured by brief frosts in southern
Florida.
Botanic Name
Maesopsis eminii Engl.
Common Names
Musizi, ndunga, muhumula, esenge
Family
Rhamnaceae
Main Attributes
Maesopsis eminii is a quickgrowing,
short-lived species suggested for enrichment planting in the humid tropics where
it grows well if the canopy opening is sufficient and there is no dense shade.
It is also recommended for well-drained grassy areas of watercourses.
Description
This fast-growing deciduous tree is cylindrical,
straight, free of branches for 9-20 m, and has a wide-spreading crown. The size
of the tree decreases across the African continent from east to west. In Nigeria
it is seldom over 15 m high, while in Uganda it grows to 36 m.
Distribution
The species is native to tropical Central Africa
from Liberia to Tanzania, covering a range of latitudes from 8°N to
2°S. Plantations have been established or natural forests managed in Fiji,
Indonesia, Malaysia, Kenya, Tanzania, Uganda, and Zaire. Trials have been
established in other African countries and in Costa Rica, Hawaii, Western Samoa,
and the Solomon Islands.
Use as Firewood
Plantation wood of Maesopsis eminii is light
and therefore is not an ideal fuelwood. Its specific gravity is 0.38-0.48.
Yield
On good soils in Africa the tree may grow 2-3 m in
height per year while it is young. In Uganda, musizi forest plantations are
managed on a 30-year rotation, producing a final volume of 20-30 m3 per ha per
year. In many areas, yields of 8-20 m3 per ha are common; on fertile volcanic
soils of Malaysia and Indonesia annual yields even reached 20-30 m3 per ha with
a maximum of 33 m3 and 40 m3 per ha, respectively.
Other Uses
· Fruit. The fruits, which are often eaten by
animals, contain an edible oil.
· Wood. The wood of Maesopsis eminii is open "rained and light brown and, although light weight, is tough and easy to work. It tends to warp, split, or collapse during seasoning, but is used for general indoor construction, joinery, and veneers for matchboxes. It is also suitable for plywood and pulpwood. On Java, Indonesia, the species has been proposed as a substitute for Albizia falcataria because of its similar wood quality and its resistance to the Xystrocera woodborer, which damages the Albizia.
· Miscellaneous. In Zaire the trees are planted to shade
coffee and cocoa plantations.
Environmental Requirements
· Temperature. Maesopsis eminii grows in an area of mean annual temperatures ranging from 22° to 27°C, while the mean minimal temperatures of the coldest months are 16°-24°C.
· Altitude. The tree is normally found between 100 m and 700 m elevation, but in several countries, including Uganda, it grows welt up to 1,200 m.
· Rainfall. The species requires 1,200-3,000 mm of uniform summer rains.
· Soil. Maesopsis eminii is considered best suited to moderately fertile, well-drained, light-to medium-textured soils, with a neutral to acid pH.
Establishment
Natural regeneration is good; large quantities
of seed are eaten and distributed by birds. The seeds number about 700 per kg.
Artificial regeneration can be effected by direct seeding, but it is safer to
raise seedlings in nurseries. Nursery stock should be planted out as pot plants
at an early age, since the plants rapidly form long taproots. Stumps cannot be
used.
· Seed treatment. Seeds must soak in cold water for 2-3 days.
· Ability to compete with weeds. The tree cannot tolerate Imperata grass competition during its early growth, but if it has been well tended during its early years, the rather dense umbrella crown rapidly suppresses competition. It is a lightdemanding species that can be planted in pure plantations, but it can also be used for underplanting or enrichment planting in open woodlands.
Pests and Diseases
Young trees are susceptible to cankers
caused by Fusarium solani and other fungi. Bacterial wilt has been reported from
a site in Malaysia with impeded drainage. In Zaire, damage by the Monochamus
scabiosus borer has been reported.
Limitations
The species cannot stand heavy weed competition
or waterlogged soils. It is too wide crowned for use where maximum productivity
per unit of land is the aim. It does not
like
Botanic Name
Pinus caribaea Morelet
Synonyms
Pinus bahamensis Griseb., Pinus hondurensis Loock
Common Names
Caribbean pine, pitch pine, pino de la costa,
pino colorado, ocote blanco, pino caribaea de Honduras, pino macho
Family
Pinaceae
Main Attributes
Caribbean pine, which has fast initial
growth, has become one of the more important pines for commercial timber
plantations in tropical areas below 1,000 m. Because of the knowledge about the
tree and its adaptability to equatorial lowlands or degraded lowland sites, it
also deserves consideration as a fuelwood species.
Description
Pinus caribaea is a large tree that under the
best conditions may grow to 45 m in height and 135 cm in diameter. Generally the
stem is straight and the branching is regular. However, there is great variation
in tree form, particularly in the branching habits of natural stands.
Distribution
Three geographic varieties of Pinus caribaea are
distinguished. Pinus caribaea var caribaea (typical), or Caribbean pine, is
found in western Cuba and the Isle of Pines. Pinus caribaea var bahamensis,
Bahamas pine, is native to the Bahamas and Caicos Islands. Pinus caribaea var
hondurensis, Honduran pine or pino hondureno, grows in the Atlantic lowland of
Central America from northern Belize to northern Nicaragua.
Use as Firewood
Young trees often grow rapidly, and both
thinnings and branches from sawlog or pulp plantations could yield valuable
fuel. The wood is soft, moderately lightweight (specific gravity, 0.4-0.66), and
resinous.
Yield
A mean annual increment of 21-40 m3 per ha can be
achieved on suitable sites up to the thirteenth year of growth.
Other Uses
· Pulp and papermaking. Pinus caribaea from
natural forests is used in Nicaragua and Honduras for general-purpose pulpwood.
· Wood. The wood is excellent for particle board and
noncompressed fiber board. It also is
used for boat building, heavy
construction, interior joinery and furniture components, and (form permitting)
for veneer.
Environmental Requirements
· Temperature. The tree
requires a warm, equable climate with no frost. In its native habitat, mean
temperatures range from 22° to 28°C, with a maximum of 37°C and
minimum of 5°C sometimes experienced.
· Altitude. In the equatorial zone, the species grows best at altitudes below 1,000 m, although it is planted up to 1,500 m.
· Rainfall. Throughout its natural habitat, Pinus caribaea grows in a climate with summer rainfall and a winter dry season. On the islands and on most inland areas, rainfall varies between 1,000 mm and 1,800 mm. In coastal areas rainfall may reach 3,900 mm, with poorly drained sites sometimes becoming waterlogged at the height of the rains. Some stands, however, grow on sites where annual rainfall may be as low as 660 mm.
· Soil. Soils are usually loams or sandy loams, sometimes with high amounts of gravel and generally well drained. The pH is usually between 5.0 and 5.5, although the very thin layer of soil on top of the coral platforms of the Bahamas has a pH of 8.4. In Cuba the soil is a deep, fine-grained clay that allows easy movement of air and water. In mainland coastal plains, Pinus caribaea occupies the well-aerated sands and silts and the levee banks where pH is between 4 and 5. Inland it can be found on a wide range of parent materials.
Establishment
Easy germination and rapid early growth reduce
costs of seedling production. It is essential to ensure that the correct
mycorrhizae are available in the nursery soil to ensure root infection.
· Seed treatment. The seeds sometimes respond to moderate stratification, that is, a 24hour water soak followed by 2-3 days of cold storage at 4°-5°C. They can be stored up to 10 years at 0°-5°C with moisture content below 10 percent.
· Ability to compete with weeds. Pinus caribaea can bear
severe competition from shallow-rooted grasses, except when rainfall is below
1,000 mm. It is light demanding and cannot tolerate much overhead shade from
tall grasses. Fast initial growth is typical of the species, and therefore
weeding is often required for only one year after planting; weeding
must
continue longer when the trees compete with climbing vines because of
little shade production.
Pests and Diseases
This species is susceptible to soil-borne
pathogens that cause "damping off" and to various fungi that cause foliage
blights, needle cast, dieback, stem and root damage, heart rot, and sap stain,
depending on the location of the plantation. Serious insect pests are
Dendroctonus (in Central American natural populations); Ips beetles; the pine
aphid; leaf-cutting ants; termites; the Australian case moth, Hyalarcta; and the
Nantucket tip moth, Rhyacionia. Damage to young plantations has been caused by
squirrels, porcupines, and tree shrews feeding on the bark of stems and
branches.
Limitations
The great genetic variation existing within this
species suggests abundant possibilities for genetic improvement in yield, stem
form, growth, branching habit, and pest resistance. Indigenous seed of Pinus
caribaea is available through commercial sources. However, in the short term,
difficulties may be encountered in procuring seed for large plantations because
the tree is so successful that seed is in high demand. In addition, outside its
native habitat Pinus caribaea produces cones at low altitudes in the tropics,
which reduces seed
supplies.
Botanic Name
Psidium guajava L.
Common Names
Guava, guayaba
Family
Myrtaceae
Main Attributes
In high-population areas guava should be a
good tree for use as firewood. It coppices readily and its growth rate is rapid
at first and slower as the tree ages. Its ability to withstand repeated cutting
should make it an exceptionally fine firewood, although the plant can be a
problem weed and its wider planting should be encouraged only where enough
utilization to keep it in check can be assured.
Description
Guava is generally a shrub or low, wide-spreading
evergreen tree 3-10 m high. It branches close to the ground and often produces
suckers from roots near the base of the trunk. The small, fragrant white flowers
are solitary or grow in small clusters on new axiliary shoots.
Distribution
Guava is indigenous to the American tropics,
where it occurs wild and cultivated. At an early date the Spanish took it to the
Philippines and the Portuguese to India. It then spread throughout the tropics.
It has been naturalized in many countries, being spread by birds; in some places
it has become a troublesome weed in pastures and has been declared a noxious
weed in Fiji.
Use as Firewood
The hard, strong, heavy wood has a specific
gravity of 0.8 and makes excellent firewood and charcoal. The gross calorific
value per gram of dry matter (ash free) is 4,792 kcal with 0.85 percent ash.
Yield
Firewood cutting causes the guava to spread by
suckering, and it may become a pest in high-rainfall areas.
Other Uses
· Fruits. Guava fruits are made into
preserves, jam, jelly, paste, juice, and nectar. They contain two to five times
the vitamin C content of fresh orange juice, and red guavas are also a good
source of vitamin A.
· Leaves. In some countries the tannin-rich leaves and green fruits are used for dyeing and tanning.
· Wood. Because of its strength the wood has been used for tool handles and implements.
Environmental Requirements
· Temperature. The trees are
susceptible to frost, but if the freeze is not too severe they grow back quickly
by suckering from below the soil. They require light.
· Altitude. Guava grows in the tropics from sea level to 1,500 m. However, it normally grows slowly at altitudes above 800 m.
· Rainfall. Psidium gunjava does well in areas of 1,000 mm or more of well-distributed rainfall, and it can endure 4-5 months of drought.
· Soil. Guava does well on slightly to strongly acid soils. It flourishes in Florida on limestone and marl with a pH of 7.5-8.0. It grows relatively poorly in heavy clay soils; however, it is reported to tolerate flooding and to grow in areas where drainage is poor.
Establishment
The tree can be propagated from seeds,
cuttings, and suckers, or by inarching. In the past, most guavas have been grown
from seed, but because of the great variability of guava fruits, vegetative
propagation (for example, air layering) of superior clones is more common.
· Seed treatment. None required. The seeds remain viable for several months and will germinate in 3-5 weeks in the warm season.
·Ability to compete with weeds. Excellent. C;uava is an aggressive plant that can withstand partial shading and can take over a site when it receives full sunlight.
Pests and Diseases
Fruit flies, mealy bugs, scale insects,
and thrips are reported to cause damage to the guava, mostly to the fruit. Wilt,
the most serious enemy of the tree in lndia, reportedly occurs on soil above pH
7.5 and is usually fatal. Bark canker and dieback are diseases that kill
branches. A bark-eating caterpillar and mealy scale may cause severe damage.
Limitations
The trees can become serious pests, particularly
with the root suckering induced by firewood cutting.
Related Species
· Psidium littorale is a native of
Brazil that grows to a height of 8 m and can grow in dense shade as well as in
the open. It is a good understory firewood in eucalyptus plantations in wet
areas (5,000-6,000 mm rainfall). It also tolerates considerably lower
temperatures and higher elevations than Psidium
guajava.
 |
 |
