Kibale National Park (795 km2) is
located in western Uganda (0 13' - 0 41' N and 30 19' - 30 32' E)
near the foothills of the Ruwenzori Mountains and contains moist
evergreen forest (Struhsaker, 1975; 1997; Chapman et al., 1997;
Chapman and Lambert, 2000, Chapman et al. 2000). The park consists
of mature, mid-altitude, moist semi-deciduous and evergreen forest
(57%), grassland (15%), woodland (4%), lakes and wetlands (2%),
colonizing forest (19%), and plantations of exotic trees (1%; primarily
Cupressus lusitanica, Pinus patula, P. caribaea, and Eucalyptus
spp.; Chapman and Lambert, 2000; the pine plantations are currently
being removed and indigenous vegetation is being allowed to grow).
| Photo: Arthur Mugisha
Mean annual rainfall in the region
is 1750 mm (1990-1999, or 1543 mm from 1903-2000, see evidence of
climate change below); the mean daily minimum temperature is 15.5
Co; and the mean daily maximum temperature is 23.7 Co (1990-1999,
Chapman and Chapman, unpublished data). Rainfall is bimodal, with
two rainy seasons generally occurring from March to May and September
to November. Over the last century there has been an increase in
the amount of rainfall that the region receives annually.
Kibale forest received National Park
status in 1993. Prior to 1993, it was a Forest Reserve, gazetted
in 1932, with the stated goal of providing a sustained production
of hardwood timber (Osmaston, 1959). A polycyclic felling cycle
of 70 years was initiated, and it was recommended that logging open
the canopy by approximately 50% through the harvest of trees over
1.52 m in girth (Kingston, 1967). This history of logging led to
varying degrees of disturbance among sites.
| Photo: Arthur Mugisha
The area around MUBFS is called Kanyawara;
names after the nearby village. Foresters have classified Kanyawara
as a Parinari forest, distinguished on photo aspect maps by the
large spreading crowns of Parinari excelsa; a valuable timber tree
(Kingston, 1967; Skorupa, 1988). The presence of P. excelsa and
the subdominants found near Kanyawara (Aningeria altissima, Olea
welwitschii, Newtonia buchananii, and Chrysophyllum gorungosanum)
are thought to indicate a climax forest between 1370 m and 1525
m (Osmaston, 1959).
Within walking distance of the field
station there are 3 forestry compartments that have been disturbed
in different fashions. The K-15 forestry compartment at Kanyawara
is a 347 ha section of forest that experienced high intensity selective
felling from September 1968 through April 1969. Total harvest averaged
21 m3/ha or approximately 7.4 stems/ha (Skorupa, 1988; Struhsaker,
1997); however, incidental damage was much higher; it is estimated
that approximately 50% of all trees in this compartment were destroyed
by logging and incidental damage (Skorupa, 1988; Chapman and Chapman,
1997). A total of 18 tree species were harvested, with nine species
contributing more than 95% of the harvest volume (Kasenene, 1987;
Forestry compartment K-14, a 405
ha forest block, experienced low intensity selective felling from
May through December 1969 (averaging 14m3/ha or 5.1 stems/ha). Twenty-three
tree species were harvested, with nine species accounting for 94%
of before harvest volume. Approximately 25% of all trees in compartment
K-14 were destroyed by logging and incidental damage (Skorupa, 1988;
Struhsaker, 1997). Harvest was not evenly distributed in this forestry
compartment (Struhsaker, 1997; Chapman and Chapman, 1997). As a
result, we divided this compartment into two areas: a moderately
logged area (Mikana) and a lightly logged area, where stump and
gap enumeration suggests only a few selected trees were removed
K-30 is a 282-ha area that has not
been commercially harvested. However, prior to 1970, a few large
stems (0.03 to 0.04 trees/ha) were removed by pitsawyers. This extremely
low level of extraction seems to have had very little impact on
the structure and composition of the forest (Skorupa, 1988; Struhsaker,
1997). Hence, compartment K-30 serves as one of the control plots
for some of our comparisons. As a control, we are assuming that
differences between the unlogged K-30 compartment and the logged
compartments (K-14, K-15) are due primarily to the effects of logging.
However, we have no means of insuring that the control and treatment
areas did not differ prior to logging, in fact they likely did differ.
Also, within walking distance are
a number of stream systems, and a system of papyrus swamps. The
forest is drained by two major everflowing rivers, Dura and Mpanga,
both of which are tributaries of Lake George. These rivers are fed
by numerous small forest streams, many of which are intermittent.
Extensive valley swamps dominated by papyrus characterize both river
systems. The closest papyrus swamp is the Rwembaita Swamp, which
is one of the larger papyrus swamps in the park (approximately 6.5
km in length) and feeds the Njuguta River, a tributary of the Mpanga
River. Several small intermittent streams feed into the Rwembaita
Swamp, and much of the system runs through an area that was selectively
logged 30 years ago. In such valley swamps of the Kibale Forest,
papyrus mats are generally not floating. During drier periods, open
water is restricted to small pools and deeper channels. During the
rainy periods, the papyrus swamp is transformed into a mosaic of
interconnected channels, large pools, and inundated grassland areas.
Access to the above mentioned ecosystems
are possible by foot from Kanyawara. However, there are many other
systems found within Kibale as a whole that are accessible if one
has a 4-wheel drive vehicle.
Within Kibale as a whole, there is
an elevational gradient from north to south, which corresponds to
a north to south increase in temperature and decrease in rainfall
(Howard, 1991; Struhsaker, 19970. Corresponding to these changes,
the vegetation at these different sites varies (Chapman et al.,
19970. Foresters have classified the forest at Sebatoli and Kanyawara
as Parinari forest, distinguished on photo aspect maps by large
spreading crowns of Parinari excelsa (Kingston, 1967; Skorupa, 1988).
The species associated with P. excelsa change between these two
sites. At Sebatoli the major sub-dominant is Carapa grandiflora.
Near Kanyawara co-dominants included Aningeria altissima, Olea welwitschii,
Newtonia buchananii, and Chrysophyllum gorungosanum. These assemblages
are thought to represent climax forests between 1370 m and 1525
m (Osmaston, 1959). At Dura River these species are less common;
Pterygota mildbraedii, Cola gigantea, Pipadeniastrum africanum,
and Chrysophyllum albidum are the dominant tree species. Further
south at Mainaro, the forest is dominated by Cynometra alexandri
and it's affiliated species. Detailed enumeration of the tree community
of these areas is provided by Chapman et al. (1997) and Chapman
et al. (in prep).
In the far south there are opportunities
to study forest restoration. The clearing of land for agriculture
has occurred primarily in the south of the park in an area known
as the southern corridor, particularly in the Kibale Forest Corridor
Game Reserve, which links Kibale with Queen Elizabeth National Park.
This game reserve was managed by a separate government agency from
the rest of the reserve and had an area of 340 km2, of which 134
km2 had dual status and lay within the Forest Reserve and Game Reserve
(van Orsdol, 1986; MISR, 1989; Howard, 1991; Struhsaker, 1997).
As early as 1971, illegal destruction and encroachment occurred
in the corridor. In 1976, some 30 eviction orders were issued, but
were never carried out. In 1983, the government again ordered settlers
out of these encroached areas, and by 1984, it was estimated that
60% of the forest plots and 30% of the grassland plots had been
abandoned. However, the situation soon reverted to the prior state
and encroachment increased. On April 1st, 1992, the government ordered
settlers off the land, and with the aid of a United Nations Program
resettled all encroachers (MISR, 1989). Estimates of the number
of people residing in the southern corridor vary dramatically. Based
on aerial surveys counting houses van Orsdol (1986) estimated that
8,800 people were living in the southern corridor. A national census
carried out in 1980 indicated that as many as 17,000 people were
residing in Kibale. Baranga (1991) estimated 40,000 people, MISR
(1989) reported some 60,000 people, and after the resettlement the
National Environmental Management Authority (1997) estimated that
30,000 households, or approximately 170,000 people, were residing
in Kibale. The extreme variance in these estimates (8,800 to 170,000)
illustrates the need for careful research prior to the initiation
of resettlement programs. Based on our surveys conducted just after
the resettlement program was completed, it is our impression that
most of these estimates are high and it seems likely that the larger
estimates were politically and economically motivated. However,
whichever estimate one chooses, it is evident that a large number
of people were residing in the southern corridor.
Baranga, J. Kibale Forest Game Corridor: man or
wildlife?, pp. 371-375 in NATURE CONSERVATION: THE ROLE OF CORRIDORS.
D.A Saunders; R.J. Hobbs, eds. London, Surrey Beatty and Sons, 1991.
Chapman, C.A., Balcomb, S.R., Gillespie, T., Skorupa, J. and Struhsaker,
T.T. 2000. Long-term effects of logging on African primate communities:
A 28 year comparison from Kibale National Park, Uganda. Conserv.
Chapman, C.A. and Chapman, L.J. (1997) Forest regeneration in logged
and unlogged forests of Kibale National Park, Uganda. Biotropica
Chapman, C.A., Chapman L.J., Wrangham R., Isabirye-Basuta G. and
Ben-David K. (1997) Spatial and temporal variability in the structure
of a tropical forest. Afr. J. Ecol. 35,287-302.
Chapman, C.A. and Lambert, J.E. (2000) Habitat alteration and the
conservation of African Primates: a case study of Kibale National
Park, Uganda. Am. J. Primatol. 50,169-186.
Chapman, C.A.; Chapman, L.J. Forest regeneration in logged and unlogged
forests of Kibale National Park, Uganda. BIOTROPICA 29:396-412,
Chapman, C.A.; Chapman, L.J.; Wrangham, R.; Isabirye-Basuta, G.;
Ben-David, K. Spatial and temporal variability in the structure
of a tropical forest. AFRICAN JOURNAL OF ECOLOGY 35:287-302, 1997.
Howard, P.C. NATURE CONSERVATION IN UGANDA'S TROPICAL FOREST RESERVES.
IUCN, Gland, Switzerland, 1991. Kingston, B. WORKING PLAN FOR KIBALE
AND ITWARA CENTRAL FOREST RESERVES. Entebbe, Uganda, Uganda Forest
MISR (Makerere Institute for Social Research). SETTLEMENT IN FOREST
RESERVES GAME RESERVES AND NATIONAL PARKS. Kampala, Uganda, Makerere
University Press, 1989.
National Environment Management Authority (NEMA). KABAROLE DISTRICT
ENVIRONMENT PROFILE. Kampala, Uganda, NEMA, 1997.
van Orsdol, K.G. Agricultural encroachment in Uganda's Kibale Forest.
ORYX 20:115-117, 1986. Osmaston, H.A. WORKING PLAN FOR THE KIBALE
AND ITWARA FORESTS. Entebbe, Uganda, Uganda Forest Department, 1959.
Skorupa, J.P. THE EFFECT OF SELECTIVE TIMBER HARVESTING ON RAIN-FOREST
PRIMATES IN KIBALE FOREST, UGANDA. Ph.D. dissertation, University
of California, Davis, 1988.
Struhsaker, T.T. THE RED COLOBUS MONKEY. Chicago, University of
Chicago Press, 1975.
Struhsaker, T.T. ECOLOGY OF AN AFRICAN RAIN FOREST: LOGGING IN KIBALE
AND THE CONFLICT BETWEEN CONSERVATION AND EXPLOITATION. Gainesville,
Florida, The University Presses of Florida, 1997.