A researcher sampled invertebrate fauna on the forest floor of Semuliki National Park in Uganda over three days during the rainy season. A total of 130 specimens from 23 species were found, including insects, spiders, snails, worms, and crabs. More individuals and species were found in the soil layer compared to the leaf layer. Additional sampling may reveal more species. Maps and temperature data from sampling sites are provided in an appendix.

1. Progress report of findings to the Monitoring & Research unit of the UWA,
April 2015
-------------------------------------------------------------------------------------------
1
The invertebrate fauna on the forest floor of the Semuliki rain forest
Zvi Sever
Biology Dep., University of Indianapolis, Indiana, U.S.A
tvision.net.ilsev@ne
In order to obtain data on the invertebrates inhabiting the forest floor of a lowland
tropical rain forest, I sectioned off during the rainy season (April 2015) a 3 sq.km.
area populated by mixed evergreen forest in south east (between Sempaya and
Bumaga, see map 1) of Semuliki N.P,(extension of Ituri forest) west Uganda on the
D.R.C. border. Two samples a day (one between trees and one between a tree's
buttresses) were taken over a 3 day period, composed of 80x80 cm of leaves and soil
that had been filtered through nets (2x2 cm to 3x3 mm). The ground was filtered to a
depth of 1 cm (6 liter each time .)
A total of 130 specimens were caught. Accordingly, 42 specimens covering 16
species were found on the ground surface (leaf layer, average depth of 5.3 cm :)
1species of amphibian, 1 species of millipede, 1 land crab, 1 earth worm, 2 spiders, 4
snails and 6 species of insects .
The 80X80X1 cm volume of filtered soil produced 88 specimens from a total of 15
species: 1 species of centipede, 1 species of millipede, 1 land crab, 1 spider, 1 earth
worm, 1 unidentified, 4 snails and 5 species of insects .
The leaf layer and the surface layer contained more insects than species from other
classes.
In both the leaf layer and the surface/soil layer, the same 8 species were found, that
is, a sum total of 23 different species of animals (mostly invertebrates) were
observed .
By calculating how many individuals were found in each layer, we can observe that
the greatest number of individuals is present in the soil layer. This can probably be

2. Progress report of findings to the Monitoring & Research unit of the UWA,
April 2015
-------------------------------------------------------------------------------------------
2
attributed to the fact that the soil is more humid even during the rainy season. In
both layers the largest number of specimens is between trees' buttresses. It can be
explained by the ground and leaf accumulation between the buttresses which makes
them reach habitat.
It was apparent that additional filtering during the rainy season might produce a
much longer list of species in both layers. It would be of interest for future research
to conduct comparative studies on the forest floor of different flora in Semuliki N.P.
(see map 2) and in other rain forests of the country, as well as in other rain forests of
Africa and other continents.
See appendix:
Appendix to the Forest floor's research
Please find attached the next data:
1. The temperatures in the filtration sites …………………….. p.3
2. The animals' list and pictures ……………..……………….. p.3
Phylum – VERTEBRATA …………………………………. P.3
Phylum – ARTHROPODA ………………………………… p.4
Phylum – MOLUSCA ……………………………………… p.8
Phylum – ANNELIDAE …………………………………… p.9
3. Maps ………………………………………………………. p.01

3. Progress report of findings to the Monitoring & Research unit of the UWA,
April 2015
-------------------------------------------------------------------------------------------
3
1. Temperatures
The temperatures were measured in all the filtration sites every hour from 8:30 to
10:30 am.
Stratum measured Average (c°)
Air – 5 cm above the leaves……………………..... 23.6
On leaves' surface ……………………………..…. 23.3
Among the leaves ……………………………..…. 22.8
On the ground surface under the leaves …………. 23.0
In the ground (depth 2 cm) ………………………. 18.9
It is possible to see that as much as we measured deeper to the leaves and ground the
temperature is lower.
2. The animals' list and pictures (23 different species were observed)
(The pictures of some animals were sent to en experts for final identification).
Body length - in mm.
Phylum – VERTEBRATA
Class - AMPHIBIA
1) Rocket frog
3.3 mm-

4. Progress report of findings to the Monitoring & Research unit of the UWA,
April 2015
-------------------------------------------------------------------------------------------
4
6 Eggs (diameter 3 mm)-
Phylum – ARTHROPODA
Class - ARACHNIDAE
Order - ARANEAE
3 species of spiders
2) Spider A- ran away before identification
3) Spider B- eggs' laying under a leaf
4) Spider C- dead specimen
15 mm-
Class - INSECTA
5) Cockroach

5. Progress report of findings to the Monitoring & Research unit of the UWA,
April 2015
-------------------------------------------------------------------------------------------
5
mm8,01,35-
6) Cricket- ran away
- Pictures of 4 species of insects were sent to experts for identification:
7) Ant A
17 mm-
8) Ant B
- 5 mm
9) Un noun insect
- 4 mm
- Pictures of 3 caterpillars and 1 pupa were sent to experts for identification:
10) Caterpillar A
-21 mm
11) Caterpillar B

6. Progress report of findings to the Monitoring & Research unit of the UWA,
April 2015
-------------------------------------------------------------------------------------------
6
- 10 mm
12) Caterpillar C
- 6 mm
13) Pupa
-17 mm
Class - CRUSTACEA
Order - ISOPODA
Sub order - Oniscoidea
14) Armadillo
- 8, 9 mm
Sub Phylum – MYRIAPODA
Class - CHILIPODA
15) Centipede

7. Progress report of findings to the Monitoring & Research unit of the UWA,
April 2015
-------------------------------------------------------------------------------------------
7
15a - 35 mm
15b - 35 mm
15c -30 mm
Class - DIPLOPODA
16) Millipede
-45, 35, 20 mm

8. Progress report of findings to the Monitoring & Research unit of the UWA,
April 2015
-------------------------------------------------------------------------------------------
8
- 65 mm
Phylum – MOLUSCA
Class - GASTROPODA
Order – Stylommatophora
Pictures of 5 species were sent to experts for identification:
17) Snail A
-10, 9 mm
18) Snail B
-13, 13, 7 mm
19) Snail C
- 11, 10, 8 mm
20) Snail D

9. Progress report of findings to the Monitoring & Research unit of the UWA,
April 2015
-------------------------------------------------------------------------------------------
9
- 4 mm
21) Snail E
-6, 6, 6 mm
Phylum – ANNELIDAE
Class - OLIGOCHAETA
22) Earth worm
- 50, 38, 18 mm -70 mm
-110 mm
Phylum – ?
Class - ?
23) Undefined species (length 15 mm)

10. Progress report of findings to the Monitoring & Research unit of the UWA,
April 2015
-------------------------------------------------------------------------------------------
11
Dorsal
Ventral
4. Maps
Map 1- Semuliki N.P. (Photo of the map in the visitor center, April 2015)

11. Progress report of findings to the Monitoring & Research unit of the UWA,
April 2015
-------------------------------------------------------------------------------------------
11
Map 2- Plants' map of Semuliki N.P. (Fig 5.3 from Howard et all, 1991)
Howard, P.C., Butono, F., Kayondo-Jjemba, P., and Muhumuzaa, C. (1991).
Integrating forest conservation into district development: a case study. Chapter 5
in: Howard, P.C. (Ed.). Nature Conservation in Uganda's Tropical Forest
Reserves. IUCN, Gland, Switzerland and Cambridge, UK. Xvii. 313 pp.